WorldWideScience

Sample records for current experimental techniques

  1. Experimental Techniques

    International Nuclear Information System (INIS)

    Fournier, D.; Serin, L.

    1995-01-01

    Experimental techniques to be used in the new generation of high energy physics are presented. The emphasis is put on the new ATLAS and CMS detectors for the CERN LHC. For the most important elements of these detectors, a description of the underlying physics processes is given, sometimes with reference to comparable detectors used in the past. Some comparative global performances of the two detectors are also given, with reference to benchmark physics processes (detection of the Higgs boson in various mass regions, etc). (author)

  2. Experimental techniques

    International Nuclear Information System (INIS)

    Roussel-Chomaz, P.

    2007-01-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, γ detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  3. Experimental techniques; Techniques experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Roussel-Chomaz, P. [GANIL CNRS/IN2P3, CEA/DSM, 14 - Caen (France)

    2007-07-01

    This lecture presents the experimental techniques, developed in the last 10 or 15 years, in order to perform a new class of experiments with exotic nuclei, where the reactions induced by these nuclei allow to get information on their structure. A brief review of the secondary beams production methods will be given, with some examples of facilities in operation or under project. The important developments performed recently on cryogenic targets will be presented. The different detection systems will be reviewed, both the beam detectors before the targets, and the many kind of detectors necessary to detect all outgoing particles after the reaction: magnetic spectrometer for the heavy fragment, detection systems for the target recoil nucleus, {gamma} detectors. Finally, several typical examples of experiments will be detailed, in order to illustrate the use of each detector either alone, or in coincidence with others. (author)

  4. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A; Laird, J S; Bardos, R A; Legge, G J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T; Sekiguchi, H [Electrotechnical Laboratory, Tsukuba (Japan).

    1994-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  5. Low current beam techniques

    Energy Technology Data Exchange (ETDEWEB)

    Saint, A.; Laird, J.S.; Bardos, R.A.; Legge, G.J.F. [Melbourne Univ., Parkville, VIC (Australia). School of Physics; Nishijima, T.; Sekiguchi, H. [Electrotechnical Laboratory, Tsukuba (Japan).

    1993-12-31

    Since the development of Scanning Transmission Microscopy (STIM) imaging in 1983 many low current beam techniques have been developed for the scanning (ion) microprobe. These include STIM tomography, Ion Beam Induced Current, Ion Beam Micromachining and Microlithography and Ionoluminense. Most of these techniques utilise beam currents of 10{sup -15} A down to single ions controlled by beam switching techniques This paper will discuss some of the low beam current techniques mentioned above, and indicate, some of their recent applications at MARC. A new STIM technique will be introduced that can be used to obtain Z-contrast with STIM resolution. 4 refs., 3 figs.

  6. Experimental technique of neutron reflection

    International Nuclear Information System (INIS)

    Chen Bo; Huang Chaoqiang; Li Xinxi

    2006-12-01

    It is presented that the classifications, structures and components of neutron reflectometer (NR), as well s functions and parameters of each components, detailed characters of NR facility 'PRN-2M'. Based on the practical experiments, the basic experimental techniques, the measurement and the related experimental settings are described, including the choice of experimental conditions, adjustments of polarized neutron beam line, basic experimental technique and approach of measurement. The above can be an instruction for NR experiments and a reference for NR construction. (authors)

  7. Strongly correlated systems experimental techniques

    CERN Document Server

    Mancini, Ferdinando

    2015-01-01

    The continuous evolution and development of experimental techniques is at the basis of any fundamental achievement in modern physics. Strongly correlated systems (SCS), more than any other, need to be investigated through the greatest variety of experimental techniques in order to unveil and crosscheck the numerous and puzzling anomalous behaviors characterizing them. The study of SCS fostered the improvement of many old experimental techniques, but also the advent of many new ones just invented in order to analyze the complex behaviors of these systems. Many novel materials, with functional properties emerging from macroscopic quantum behaviors at the frontier of modern research in physics, chemistry and materials science, belong to this class of systems. The volume presents a representative collection of the modern experimental techniques specifically tailored for the analysis of strongly correlated systems. Any technique is presented in great detail by its own inventor or by one of the world-wide recognize...

  8. Experimental techniques and measurement accuracies

    International Nuclear Information System (INIS)

    Bennett, E.F.; Yule, T.J.; DiIorio, G.; Nakamura, T.; Maekawa, H.

    1985-02-01

    A brief description of the experimental tools available for fusion neutronics experiments is given. Attention is paid to error estimates mainly for the measurement of tritium breeding ratio in simulated blankets using various techniques

  9. Experimental study of neoclassical currents

    International Nuclear Information System (INIS)

    Zarnstorff, M.C.; Prager, S.C.

    1985-05-01

    A detailed experimental study is presented of the bootstrap and Pfirsch-Schlueter currents that are predicted by neoclassical transport theory. In a toroidal octupole, on magnetic surfaces within the separatrix, the observed parallel plasma currents are in excellent quantitative agreement with neoclassical theory with regard to the spatial structure (along a magnetic surface), collisionality dependence and toroidal magnetic field dependence. On magnetic surfaces outside the separatrix, the ion portion of the parallel current is in agreement with neoclassical theory but the electron parallel current is observed to obtain a unidirectional component which deviates from and exceeds the theoretical prediction

  10. Nanorobotics current approaches and techniques

    CERN Document Server

    Ferreira, Antoine

    2013-01-01

    Nanorobot devices now perform a wide variety of tasks at the nanoscale in a wide variety of fields including but not limited to fields such as manufacturing, medicine, supply chain, biology, and outer space. Nanorobotics: Current Approaches and Techniques is a comprehensive overview of this interdisciplinary field with a wide ranging discussion that includes nano-manipulation and industrial nanorobotics, nanorobotics in biology and medicine, nanorobotic sensing, navigation and swarm behavior, and protein and DNA-based nanorobotics. Also included is the latest on topics such as bio-nano-actuators and propulsion and navigation of nanorobotic systems using magnetic fields. Nanorobotics: Current Approaches and Techniques is an ideal book for scientists, researchers, and engineers actively involved in applied and robotic research and development.

  11. Experimental modeling of eddy current inspection capabilities

    International Nuclear Information System (INIS)

    Junker, W.R.; Clark, W.G.

    1984-01-01

    This chapter examines the experimental modeling of eddy current inspection capabilities based upon the use of liquid mercury samples designed to represent metal components containing discontinuities. A brief summary of past work with mercury modeling and a detailed discussion of recent experiments designed to further evaluate the technique are presented. The main disadvantages of the mercury modeling concept are that mercury is toxic and must be handled carefully, liquid mercury can only be used to represent nonferromagnetic materials, and wetting and meniscus problems can distort the effective size of artificial discontinuities. Artificial discontinuities placed in a liquid mercury sample can be used to represent discontinuities in solid metallic structures. Discontinuity size and type cannot be characterized from phase angle and signal amplitude data developed with a surface scanning, pancake-type eddy current probe. It is concluded that the mercury model approach can greatly enhance the overall understanding and applicability of eddy current inspection techniques

  12. Submucosal tunneling techniques: current perspectives.

    Science.gov (United States)

    Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

    2014-01-01

    Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments.

  13. NOAA NOS SOS, EXPERIMENTAL - Currents

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA NOS SOS server is part of the IOOS DIF SOS Project. The stations in this dataset have currents data. *These services are for testing and evaluation use...

  14. An experimenter's history of neutral currents

    International Nuclear Information System (INIS)

    Sciulli, F.

    1979-01-01

    The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

  15. Compensation techniques for operational amplifier bias current

    International Nuclear Information System (INIS)

    Silva, M.S.

    1981-01-01

    Two techniques are proposed for the compensation of the input current on operational amplifiers that can be used on inverting and non-inverting configurations. A qualitative analysis of temperature drift problems is made, and as a practical application, the construction of a voltage follower for high impedance measurements is presented. (Author) [pt

  16. Phase equilibria basic principles, applications, experimental techniques

    CERN Document Server

    Reisman, Arnold

    2013-01-01

    Phase Equilibria: Basic Principles, Applications, Experimental Techniques presents an analytical treatment in the study of the theories and principles of phase equilibria. The book is organized to afford a deep and thorough understanding of such subjects as the method of species model systems; condensed phase-vapor phase equilibria and vapor transport reactions; zone refining techniques; and nonstoichiometry. Physicists, physical chemists, engineers, and materials scientists will find the book a good reference material.

  17. Experimental studies of coaxial plasma gun current

    International Nuclear Information System (INIS)

    Price, D.W.

    1988-01-01

    In this investigation of a coaxial plasma gun, plasma sheath currents and related behavior are examined. Plasma behavior in the gun affects gun characteristics. Plasma gun applications are determined by the plasma behavior. The AFWL PUFF capacitor bank (72 μF, 29 nH, 120 kV) drives the plasma gun using a deuterium fill gas. The gas breakdown site is isolated from the dielectric/vacuum interface in the AFWL system. Two gas values deliver gas in the system. The first delivers gas from the gun breech and the second optional valve delivers gas to the gun muzzle. Currents and voltages are measured by Rogowski coils, B probes and capacitive voltage probes. A O-D slug model is used to predict the current, inductance, gun voltage and plasma sheath velocity. The slug model assumes the sheath transits the gun with all mass in the sheath. In the snowplow mode, the plasma sheath is thin with a sharp current rise and drop. Our system operated in a transition mode between the snowplow and deflagration modes with early snowplow behavior and late deflagration behavior. Neutrons are produced in a plasma pinch at the gun muzzle, indicating snowplow behavior. The slug theory models overall gun behavior to experimental accuracy. Experimental results are compared to four theories for plasma sheath velocities: the Alfven collisionally limited model, the Rosenbluth model, the Fishbine saturated model and a single particle drift model. Experimental velocities vary from 10 5 to 10 6 m/s. Only the single particle drift and the slug model calculations are of the right magnitude (8 x 10 5 m/s). The Fishbine and the Rosenbluth models predict slower velocities (2 x 10 5 m/s). The Alfven model is not applicable to this system

  18. Immunoperoxidase technique in experimental chronic chagasic myocarditis

    OpenAIRE

    M.d. Maria Celina Morales; M.D. José Milei

    1987-01-01

    Chagas'disease has been described as the commonest form of chronic myocarditis. An immunologic pathogenesis has been discribed for this form of the disease. So far, no immunoperoxidase technique has been used for the detection of immunological deposits in chronic experimental Chagas'myocardiopathy. Forty-one Swiss mice, three months old were inoculated intraperitoneally with doses between 10 and 10(5) Tulahuen trypomastigotes. Mice were reinoculated one month after with doses between 10² and ...

  19. Machine monitoring via current signature analysis techniques

    International Nuclear Information System (INIS)

    Smith, S.F.; Castleberry, K.N.; Nowlin, C.H.

    1992-01-01

    A significant need in the effort to provide increased production quality is to provide improved plant equipment monitoring capabilities. Unfortunately, in today's tight economy, even such monitoring instrumentation must be implemented in a recognizably cost effective manner. By analyzing the electric current drawn by motors, actuator, and other line-powered industrial equipment, significant insights into the operations of the movers, driven equipment, and even the power source can be obtained. The generic term 'current signature analysis' (CSA) has been coined to describe several techniques for extracting useful equipment or process monitoring information from the electrical power feed system. A patented method developed at Oak Ridge National Laboratory is described which recognizes the presence of line-current modulation produced by motors and actuators driving varying loads. The in-situ application of applicable linear demodulation techniques to the analysis of numerous motor-driven systems is also discussed. The use of high-quality amplitude and angle-demodulation circuitry has permitted remote status monitoring of several types of medium and high-power gas compressors in (US DOE facilities) driven by 3-phase induction motors rated from 100 to 3,500 hp, both with and without intervening speed increasers. Flow characteristics of the compressors, including various forms of abnormal behavior such as surging and rotating stall, produce at the output of the specialized detectors specific time and frequency signatures which can be easily identified for monitoring, control, and fault-prevention purposes. The resultant data are similar in form to information obtained via standard vibration-sensing techniques and can be analyzed using essentially identical methods. In addition, other machinery such as refrigeration compressors, brine pumps, vacuum pumps, fans, and electric motors have been characterized

  20. Experimental techniques in nuclear and particle physics

    International Nuclear Information System (INIS)

    Tavernier, Stefaan

    2010-01-01

    The book is based on a course in nuclear and particle physics that the author has taught over many years to physics students, students in nuclear engineering and students in biomedical engineering. It provides the basic understanding that any student or researcher using such instruments and techniques should have about the subject. After an introduction to the structure of matter at the subatomic scale, it covers the experimental aspects of nuclear and particle physics. Ideally complementing a theoretically-oriented textbook on nuclear physics and/or particle physics, it introduces the reader to the different techniques used in nuclear and particle physics to accelerate particles and to measurement techniques (detectors) in nuclear and particle physics. The main subjects treated are: interactions of subatomic particles in matter; particle accelerators; basics of different types of detectors; and nuclear electronics. The book will be of interest to undergraduates, graduates and researchers in both particle and nuclear physics. For the physicists it is a good introduction to all experimental aspects of nuclear and particle physics. Nuclear engineers will appreciate the nuclear measurement techniques, while biomedical engineers can learn about measuring ionising radiation, the use of accelerators for radiotherapy. What's more, worked examples, end-of-chapter exercises, and appendices with key constants, properties and relationships supplement the textual material. (orig.)

  1. Experimental techniques in nuclear and particle physics

    CERN Document Server

    Tavernier, Stefaan

    2009-01-01

    The book is based on a course in nuclear and particle physics that the author has taught over many years to physics students, students in nuclear engineering and students in biomedical engineering. It provides the basic understanding that any student or researcher using such instruments and techniques should have about the subject. After an introduction to the structure of matter at the subatomic scale, it covers the experimental aspects of nuclear and particle physics. Ideally complementing a theoretically-oriented textbook on nuclear physics and/or particle physics, it introduces the reader to the different techniques used in nuclear and particle physics to accelerate particles and to measurement techniques (detectors) in nuclear and particle physics. The main subjects treated are: interactions of subatomic particles in matter; particle accelerators; basics of different types of detectors; and nuclear electronics. The book will be of interest to undergraduates, graduates and researchers in both particle and...

  2. LAMPF experimental-area beam current monitors

    International Nuclear Information System (INIS)

    Tallerico, P.J.

    1975-01-01

    This paper summarizes the design and operational performance of a wide- range current monitor system used to measure charged-particle currents in the experimental areas of the Clinton P. Anderson Meson Physics Facility (LAMPF), a proton accelerator. The major features of the system are high sensitivity, wide dynamic range, and the ability to withstand high levels of radiation. The current pulses detected are from 50 μs to 1 ms in duration at repetition rates of from 1 to 120 Hz. The pulse amplitude varies from 1 μA to 17 mA of protons or H - ions. Both real-time and integrated outputs are available, and the minimum detectable currents are 1 μA at the video output and 50 nA at the integrated output. The basic system is comprised of toroids, preamplifiers, signal conditioners, voltage-to-frequency converters, and digital accumulators. The entire system is spread out over 1 km of beam pipe. Provision is made for calibration and for sending the outputs to remote users. The system is normally controlled by a small digital computer, which allows the system to be quite flexible in operation. The design features of the toroids and the associated electronics are discussed in detail, with emphasis on the steps taken to reduce noise and make the toroids temperature and radiation resistant

  3. Immunoperoxidase technique in experimental chronic chagasic myocarditis

    Directory of Open Access Journals (Sweden)

    M.d. Maria Celina Morales

    1987-04-01

    Full Text Available Chagas'disease has been described as the commonest form of chronic myocarditis. An immunologic pathogenesis has been discribed for this form of the disease. So far, no immunoperoxidase technique has been used for the detection of immunological deposits in chronic experimental Chagas'myocardiopathy. Forty-one Swiss mice, three months old were inoculated intraperitoneally with doses between 10 and 10(5 Tulahuen trypomastigotes. Mice were reinoculated one month after with doses between 10² and 10(5 and sacrificed at 6 (n=21 and 9 months (n=9 after the first inoculation. ECGs were recorded before sacrifice. Immunoperoxidase technique (peroxidase-antiperoxidase method, immunofluorescence (direct and indirect as well as histological studies were performed in myocardiums and skeletal muscles of the surviving animals. The most sensitive methods for detecting chronic chagasic infection were the routine histologic studies (73% and the ECGs 83% and 89% on 6 and 9 mo. post-infected mice, respectively. Myocardial involvement varied from interstitial mild focal lymphocyte infiltrates up to replacement of myocytes by loose connective tissue. Atrial myocardiums (21/23, 91% were more affected than ventricles (9/23, 39%. Typical chagasic nests were rarely found. Skeletal muscle involvement (11/18 and 7/9 varied from mild to extensive lymphocyte and plasmacell infiltrates, and necrotic fibers. The involved antigen were shown in skeletal muscles by the immunoperoxidase technique as diffusely arranged granular intracytoplasmatic deposit for both IgC and total immunoglobulins. The coincidence between this technique and histologic muscle lesions was 11/18 (61(% in 6 mo. and 6/8 (75% at 9 mo. post-infection. In heart, delicate granular deposits of total immunoglobulins were seen diffusely arranged within the ventricular myocytes; coincidence between immunoperoxidase technique anl histologic involvement increased from 36 to 66% in animals sacrifeced 6 and 9 mo. post

  4. High current density ion beam measurement techniques

    International Nuclear Information System (INIS)

    Ko, W.C.; Sawatzky, E.

    1976-01-01

    High ion beam current measurements are difficult due to the presence of the secondary particles and beam neutralization. For long Faraday cages, true current can be obtained only by negative bias on the target and by summing the cage wall and target currents; otherwise, the beam will be greatly distorted. For short Faraday cages, a combination of small magnetic field and the negative target bias results in correct beam current. Either component alone does not give true current

  5. Experimental techniques for cement hydration studies

    Directory of Open Access Journals (Sweden)

    Andreas Luttge

    2011-10-01

    Full Text Available Cement hydration kinetics is a complex problem of dissolution, nucleation and growth that is still not well understood, particularly in a quantitative way. While cement systems are unique in certain aspects they are also comparable to natural mineral systems. Therefore, geochemistry and particularly the study of mineral dissolution and growth may be able to provide insight and methods that can be utilized in cement hydration research. Here, we review mainly what is not known or what is currently used and applied in a problematic way. Examples are the typical Avrami approach, the application of Transition State Theory (TST to overall reaction kinetics and the problem of reactive surface area. Finally, we suggest an integrated approach that combines vertical scanning interferometry (VSI with other sophisticated analytical techniques such as atomic force microscopy (AFM and theoretical model calculations based on a stochastic treatment.

  6. A TECHNIQUE OF EXPERIMENTAL INVESTIGATIONS OF LINEAR IMPULSE ELECTROMECHANICAL CONVERTERS

    Directory of Open Access Journals (Sweden)

    V.F. Bolyukh

    2017-04-01

    Full Text Available Purpose. Development of a technique of experimental studies linear pulse electromechanical converters parameters, which are used as shock-power devices and electromechanical accelerators, and comparing the experimental results with the calculated indices obtained using the mathematical model. Methodology. Method of experimental investigations of linear electromechanical converter is that the electrical parameters are recorded simultaneously (inductor winding current and mechanical parameters characterizing the power and speed indicators of the joke with actuator. Power indicators are primarily important for shock-power devices, and high velocity - for electromechanical accelerators. Power indices were investigated using piezoelectric sensors, a system of strain sensors, pressure pulsation sensor and high-speed videorecording. Velocity indicators were investigated using a resistive movement sensor which allows to record character of the armature movement with actuating element in each moment. Results. The technique of experimental research, which is the simultaneous recording of electrical and mechanical power and velocity parameters of the linear electromechanical converter pulse, is developed. In the converter as a shock-power device power indicators are recorded using a piezoelectric transducer, strain sensors system, pressure pulsation sensor and high-speed video. The parameters of the inductor winding current pulse, the time lag of mechanical processes in relation to the time of occurrence of the inductor winding current, the average speed of the joke, the magnitude and momentum of electrodynamics forces acting on the plate strikes are experimentally determined. In the converter as an electromechanical accelerator velocity performance recorded using resistive displacement sensors. It is shown that electromechanical converter processes have complex spatial-temporal character. The experimental results are in good agreement with the calculated

  7. Oscillation experiments techniques in CEA Minerve experimental reactor

    Energy Technology Data Exchange (ETDEWEB)

    Antony, M.; Di-Salvo, J.; Pepino, A.; Bosq, J. C.; Bernard, D.; Leconte, P.; Hudelot, J. P.; Lyoussi, A. [CEA CADARACHE, DEN/DER/SPEx, 13108 Saint Paul-lez-Durance (France)

    2009-07-01

    This paper deals with experiments in the Minerve pool Zero Power Reactor. Minerve is mainly devoted to neutronics studies, in view to improve the calculation routes by reducing the uncertainties of the experimental databases for nuclides arising in plutonium and wastes management. Minerve experimental measurement programs are performed by using the oscillation technique. This experimental technique consists in a periodic insertion and extraction of samples containing the nuclide of interest in a well characterized neutron spectrum. The reactivity variation of the sample is compensated by a calibrated rotary automatic pilot using cadmium sectors. The normal accuracy for measurements of small-worth samples in Minerve by using such a technique is about 3% for absolute reactivity worth, including the uncertainties on the material balance and on the calibration step. Reactivity effects of less than 1.5 cent can be measured. The OSMOSE and the OCEAN programs have been carried out since 2005 and will last until 2011. These programs aim at improving, in different neutron spectra, the absorption cross sections of respectively a majority of the separated heavy nuclides from {sup 232}Th to {sup 245}Cm appearing during the reactor and the fuel cycle physics, and of current and future types of absorbers as Gd, Hf, Er, Dy and Eu. (authors)

  8. Elastographic techniques of thyroid gland: current status.

    Science.gov (United States)

    Andrioli, Massimiliano; Persani, Luca

    2014-08-01

    Thyroid nodules are very common with malignancies accounting for about 5 %. Fine-needle biopsy is the most accurate test for thyroid cancer diagnosis. Elastography, a new technology directly evaluating the elastic property of the tissue, has been recently added to the diagnostic armamentarium of the endocrinologists as noninvasive predictor of thyroid malignancy. In this paper, we critically reviewed characteristics and applications of elastographic methods in thyroid gland. Elastographic techniques can be classified on the basis of the following: source-of-tissue compression (free-hand, carotid vibration, ultrasound pulses), processing time (real-time, off-line), stiffness expression (qualitative, semi-quantitative, or quantitative). Acoustic radiation force impulse and aixplorer shear wave are the newest and most promising quantitative elastographic methods. Primary application of elastography is the detection of nodular lesions suspicious for malignancy. Published data show a high sensitivity and negative predictive value of the technique. Insufficient data are available on the possible application of elastography in the differential diagnosis of indeterminate lesions and in thyroiditis. Elastography represents a noninvasive tool able to increase the performance of ultrasound in the selection of thyroid nodules at higher risk of malignancy. Some technical improvements and definition of more robust quantitative diagnostic criteria are required for assigning a definite role in the management of thyroid nodules and thyroiditis to elastography.

  9. Experimental techniques of conversion coefficient measurements

    International Nuclear Information System (INIS)

    Hamilton, J.H.

    1975-01-01

    Discusses briefly the history of conversion electron spectra measurements, and the interpretation of the collected data. Then provides a comprehensive review of techniques presently available to measure the conversion coefficients. (Auth.)

  10. Phase behavior of multicomponent membranes: Experimental and computational techniques

    DEFF Research Database (Denmark)

    Bagatolli, Luis; Kumar, P.B. Sunil

    2009-01-01

    Recent developments in biology seems to indicate that the Fluid Mosaic model of membrane proposed by Singer and Nicolson, with lipid bilayer functioning only as medium to support protein machinery, may be too simple to be realistic. Many protein functions are now known to depend on the compositio....... This review includes basic foundations on membrane model systems and experimental approaches applied in the membrane research area, stressing on recent advances in the experimental and computational techniques....... membranes. Current increase in interest in the domain formation in multicomponent membranes also stems from the experiments demonstrating liquid ordered-liquid disordered coexistence in mixtures of lipids and cholesterol and the success of several computational models in predicting their behavior...

  11. Experimental technique of small angle neutron scattering

    International Nuclear Information System (INIS)

    Xia Qingzhong; Chen Bo

    2006-03-01

    The main parts of Small Angle Neutron Scattering (SANS) spectrometer, and their function and different parameters are introduced from experimental aspect. Detailed information is also introduced for SANS spectrometer 'Membrana-2'. Based on practical experiments, the fundamental requirements and working condition for SANS experiments, including sample preparation, detector calibration, standard sample selection and data preliminary process are described. (authors)

  12. Methods and experimental techniques in computer engineering

    CERN Document Server

    Schiaffonati, Viola

    2014-01-01

    Computing and science reveal a synergic relationship. On the one hand, it is widely evident that computing plays an important role in the scientific endeavor. On the other hand, the role of scientific method in computing is getting increasingly important, especially in providing ways to experimentally evaluate the properties of complex computing systems. This book critically presents these issues from a unitary conceptual and methodological perspective by addressing specific case studies at the intersection between computing and science. The book originates from, and collects the experience of, a course for PhD students in Information Engineering held at the Politecnico di Milano. Following the structure of the course, the book features contributions from some researchers who are working at the intersection between computing and science.

  13. From experimental imaging techniques to virtual embryology.

    Science.gov (United States)

    Weninger, Wolfgang J; Tassy, Olivier; Darras, Sébastien; Geyer, Stefan H; Thieffry, Denis

    2004-01-01

    Modern embryology increasingly relies on descriptive and functional three dimensional (3D) and four dimensional (4D) analysis of physically, optically, or virtually sectioned specimens. To cope with the technical requirements, new methods for high detailed in vivo imaging, as well as the generation of high resolution digital volume data sets for the accurate visualisation of transgene activity and gene product presence, in the context of embryo morphology, were recently developed and are under construction. These methods profoundly change the scientific applicability, appearance and style of modern embryo representations. In this paper, we present an overview of the emerging techniques to create, visualise and administrate embryo representations (databases, digital data sets, 3-4D embryo reconstructions, models, etc.), and discuss the implications of these new methods on the work of modern embryologists, including, research, teaching, the selection of specific model organisms, and potential collaborators.

  14. Experimental Investigation of Centrifugal Compressor Stabilization Techniques

    Science.gov (United States)

    Skoch, Gary J.

    2003-01-01

    Results from a series of experiments to investigate techniques for extending the stable flow range of a centrifugal compressor are reported. The research was conducted in a high-speed centrifugal compressor at the NASA Glenn Research Center. The stabilizing effect of steadily flowing air-streams injected into the vaneless region of a vane-island diffuser through the shroud surface is described. Parametric variations of injection angle, injection flow rate, number of injectors, injector spacing, and injection versus bleed were investigated for a range of impeller speeds and tip clearances. Both the compressor discharge and an external source were used for the injection air supply. The stabilizing effect of flow obstructions created by tubes that were inserted into the diffuser vaneless space through the shroud was also investigated. Tube immersion into the vaneless space was varied in the flow obstruction experiments. Results from testing done at impeller design speed and tip clearance are presented. Surge margin improved by 1.7 points using injection air that was supplied from within the compressor. Externally supplied injection air was used to return the compressor to stable operation after being throttled into surge. The tubes, which were capped to prevent mass flux, provided 9.3 points of additional surge margin over the baseline surge margin of 11.7 points.

  15. Natural gas hydrates. Experimental techniques and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Yuguang; Liu, Changling (eds.) [Qingdao Institute of Marine Geology (China). Gas Hydrate Laboratory

    2013-07-01

    Focuses on gas hydrate experiment in laboratory. Intends to provide practical significant parameters for gas hydrate exploration and exploitation in the oceanic and permafrost environments. Consists of different themes that present up-to-date information on hydrate experiments. ''Natural Gas Hydrates: Experimental Techniques and Their Applications'' attempts to broadly integrate the most recent knowledge in the fields of hydrate experimental techniques in the laboratory. The book examines various experimental techniques in order to provide useful parameters for gas hydrate exploration and exploitation. It provides experimental techniques for gas hydrates, including the detection techniques, the thermo-physical properties, permeability and mechanical properties, geochemical abnormalities, stability and dissociation kinetics, exploitation conditions, as well as modern measurement technologies etc.

  16. Differential sensor in front photopyroelectric technique: II. Experimental

    International Nuclear Information System (INIS)

    Ivanov, R; Moreno, I; Araujo-Andrade, C; MarIn, E; Cruz-Orea, A; Pichardo-Molina, J L

    2009-01-01

    We describe the differential cell design and the experimental (optical and electronic) setup for the differential front photopyroelectric technique, whose theory has been developed in the first part of this paper (Ivanov et al 2008 J. Phys. D: Appl. Phys. 41 085106). We will show first how the direct (non-differential) front photopyroelectric theory described in our previous paper reproduces well the experimental results. The usefulness of the differential technique is demonstrated by means of experimental measurements of the thermal effusivity in binary ethanol-water and glycerol-water mixtures, based on a theoretical methodology that simplifies the measurement procedure and diminishes the experimental uncertainty.

  17. Differential sensor in front photopyroelectric technique: II. Experimental

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, R; Moreno, I; Araujo-Andrade, C [Facultad de Fisica, Universidad Autonoma de Zacatecas, Calz. Solidaridad Esquina Paseo de la Bufa s/n, CP 98060, Zacatecas, Zac. (Mexico); MarIn, E [Centro de Investigacion en Ciencia Aplicada y TecnologIa Avanzada-Instituto Politecnico Nacional, Legaria 694, Col. Irrigacion, CP 11500, Mexico D.F. (Mexico); Cruz-Orea, A [Departamento de Fisica, CINVESTAV-IPN, Av. IPN No. 2508, Col. San Pedro Zacatenco, CP 07360, Mexico D.F. (Mexico); Pichardo-Molina, J L, E-mail: rumen@fisica.uaz.edu.m [Centro de Investigaciones en Optica, Loma del Bosque 115, Loma del Campestre, CP 37150, Leon, Guanajuato (Mexico)

    2009-06-21

    We describe the differential cell design and the experimental (optical and electronic) setup for the differential front photopyroelectric technique, whose theory has been developed in the first part of this paper (Ivanov et al 2008 J. Phys. D: Appl. Phys. 41 085106). We will show first how the direct (non-differential) front photopyroelectric theory described in our previous paper reproduces well the experimental results. The usefulness of the differential technique is demonstrated by means of experimental measurements of the thermal effusivity in binary ethanol-water and glycerol-water mixtures, based on a theoretical methodology that simplifies the measurement procedure and diminishes the experimental uncertainty.

  18. Some current experimental challenges in elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Cline, D.B. (California Univ., Los Angeles (USA). Dept. of Physics)

    1990-06-01

    We describe three experimental challenges for experimental elementary particle physics: (1) the ongoing search for flavor changing weak neutral currents, including future prospect for a anti BB factory, (2) the status of the tests of the standard model in the W, Z and t quark sectors and (3) some current search for physics beyond the standard model, to include the possibility of searching for CPT violation using a {Phi} factory. (orig.).

  19. Electromagnetic considerations for RF current density imaging [MRI technique].

    Science.gov (United States)

    Scott, G C; Joy, M G; Armstrong, R L; Henkelman, R M

    1995-01-01

    Radio frequency current density imaging (RF-CDI) is a recent MRI technique that can image a Larmor frequency current density component parallel to B(0). Because the feasibility of the technique was demonstrated only for homogeneous media, the authors' goal here is to clarify the electromagnetic assumptions and field theory to allow imaging RF currents in heterogeneous media. The complete RF field and current density imaging problem is posed. General solutions are given for measuring lab frame magnetic fields from the rotating frame magnetic field measurements. For the general case of elliptically polarized fields, in which current and magnetic field components are not in phase, one can obtain a modified single rotation approximation. Sufficient information exists to image the amplitude and phase of the RF current density parallel to B(0) if the partial derivative in the B(0) direction of the RF magnetic field (amplitude and phase) parallel to B(0) is much smaller than the corresponding current density component. The heterogeneous extension was verified by imaging conduction and displacement currents in a phantom containing saline and pure water compartments. Finally, the issues required to image eddy currents are presented. Eddy currents within a sample will distort both the transmitter coil reference system, and create measurable rotating frame magnetic fields. However, a three-dimensional electro-magnetic analysis will be required to determine how the reference system distortion affects computed eddy current images.

  20. Dynamic Tensile Experimental Techniques for Geomaterials: A Comprehensive Review

    Science.gov (United States)

    Heard, W.; Song, B.; Williams, B.; Martin, B.; Sparks, P.; Nie, X.

    2018-01-01

    This review article is dedicated to the Dynamic Behavior of Materials Technical Division for celebrating the 75th anniversary of the Society for Experimental Mechanics (SEM). Understanding dynamic behavior of geomaterials is critical for analyzing and solving engineering problems of various applications related to underground explosions, seismic, airblast, and penetration events. Determining the dynamic tensile response of geomaterials has been a great challenge in experiments due to the nature of relatively low tensile strength and high brittleness. Various experimental approaches have been made in the past century, especially in the most recent half century, to understand the dynamic behavior of geomaterials in tension. In this review paper, we summarized the dynamic tensile experimental techniques for geomaterials that have been developed. The major dynamic tensile experimental techniques include dynamic direct tension, dynamic split tension, and spall tension. All three of the experimental techniques are based on Hopkinson or split Hopkinson (also known as Kolsky) bar techniques and principles. Uniqueness and limitations for each experimental technique are also discussed.

  1. [Intestinal lengthening techniques: an experimental model in dogs].

    Science.gov (United States)

    Garibay González, Francisco; Díaz Martínez, Daniel Alberto; Valencia Flores, Alejandro; González Hernández, Miguel Angel

    2005-01-01

    To compare two intestinal lengthening procedures in an experimental dog model. Intestinal lengthening is one of the methods for gastrointestinal reconstruction used for treatment of short bowel syndrome. The modification to the Bianchi's technique is an alternative. The modified technique decreases the number of anastomoses to a single one, thus reducing the risk of leaks and strictures. To our knowledge there is not any clinical or experimental report that studied both techniques, so we realized the present report. Twelve creole dogs were operated with the Bianchi technique for intestinal lengthening (group A) and other 12 creole dogs from the same race and weight were operated by the modified technique (Group B). Both groups were compared in relation to operating time, difficulties in technique, cost, intestinal lengthening and anastomoses diameter. There were no statistical difference in the anastomoses diameter (A = 9.0 mm vs. B = 8.5 mm, p = 0.3846). Operating time (142 min vs. 63 min) cost and technique difficulties were lower in group B (p anastomoses (of Group B) and intestinal segments had good blood supply and were patent along their full length. Bianchi technique and the modified technique offer two good reliable alternatives for the treatment of short bowel syndrome. The modified technique improved operating time, cost and technical issues.

  2. Non-Destructive Techniques Based on Eddy Current Testing

    Science.gov (United States)

    García-Martín, Javier; Gómez-Gil, Jaime; Vázquez-Sánchez, Ernesto

    2011-01-01

    Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. This paper includes an overview of the fundamentals and main variables of eddy current testing. It also describes the state-of-the-art sensors and modern techniques such as multi-frequency and pulsed systems. Recent advances in complex models towards solving crack-sensor interaction, developments in instrumentation due to advances in electronic devices, and the evolution of data processing suggest that eddy current testing systems will be increasingly used in the future. PMID:22163754

  3. Experimental typography : reviewing the modernist and the current approaches

    OpenAIRE

    Makal, Eray

    1993-01-01

    Ankara : The Department of Graphic Design and Institute of Fine Arts, Bilkent Univ., 1993. Thesis (Master's) -- Bilkent University, 1993. Includes bibliographical references leaves 65-66. The intention of this study is to evaluate the experimental typography within the history of graphic design by taking in consideration of two epochs. The Modernist and The Current. Makal, Eray M.S.

  4. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    International Nuclear Information System (INIS)

    Geinitz, Hans

    2015-01-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  5. Eddy current technique applied to automated tube profilometry

    International Nuclear Information System (INIS)

    Dobbeni, D.; Melsen, C. van

    1982-01-01

    The use of eddy current methods in the first totally automated pre-service inspection of the internal diameter of PWR steam generator tubes is described. The technique was developed at Laborelec, the Belgian Laboratory of the Electricity Supply Industry. Details are given of the data acquisition system and of the automated manipulator. Representative tube profiles are illustrated. (U.K.)

  6. Current research projects on traffic conflicts technique studies.

    NARCIS (Netherlands)

    Hondel, M. van den & and Kraay, J.H.

    1979-01-01

    A review of current research concerning the development, evaluation and use of the traffic conflicts technique is presented. The 32 studies, selected from the IRRD data base, are listed alphabetically by names of countries and under countries by names of research organizations. The IRRD descriptions

  7. Experimental Technique of Titanium Fire in Aero-engine

    Directory of Open Access Journals (Sweden)

    MI Guangbao

    2016-06-01

    Full Text Available Titanium fire is the typical catastrophic fault in the aero-engine. Aiming at the urgent demand for experimental technique of titanium fire from advanced high thrust-weight ratio aero-engine, the combustion technology and theory of titanium alloy based on friction oxygen concentration method (FOC were systematically studied. The evaluation method of fireproof property and the friction ignition model were built, and the fireproof mechanism was illustrated. By generalizing recent progress in experimental technique of titanium fire from three levels, including evolutionary rule, mechanism and prevention and control technology, the ideas and directions of experimental technique associated with the application research of titanium fire in the future were proposed, namely overall evaluation of fireproof property close to air flow environment of the aero-engine, prediction model of fireproof property and experimental verification of fireproof technique under the air flow environment of aero-engine. It is necessary to establish the prevention system of titanium fire in aero-engine, which contributes to the realization of "full titanium" in compressor and to the increase of high thrust-weight ratio.

  8. Experimental techniques for the consolidation of the neutron spectrum

    International Nuclear Information System (INIS)

    Chiaraviglio, N.; Bazzana, S.

    2013-01-01

    Unfolding techniques are widely known but their use is not widespread due to their complexity. Such procedure consists in the adjustment of calculated quantities to experimental results by the modification of the neutron spectrum, getting correction factors for the calculated quantities. In this work we describe the general procedure that must be executed for a neutron spectrum unfolding. (author) [es

  9. ELECTRONIC SYSTEM FOR EXPERIMENTATION IN AC ELECTROGRAVIMETRY I: TECHNIQUE FUNDAMENTALS

    Directory of Open Access Journals (Sweden)

    Róbinson Torres

    Full Text Available Basic fundamentals of AC electrogravimetry are introduced. Their main requirements and characteristics are detailed to establish the design of an electronic system that allows the appropriate extraction of data needed to determine the electrogravimetric transfer function (EGTF and electrochemical impedance (EI, in an experimental set-up for the AC electrogravimetry technique.

  10. Soft X-ray beam induced current technique

    Energy Technology Data Exchange (ETDEWEB)

    Watts, B; Ade, H [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Queen, D; Hellman, F [Department of Physics, University of California, Berkeley, CA 94720 (United States); Kilcoyne, A L D; Tyliszczak, T, E-mail: benjamin.watts@gmail.co [Advanced Light Source, Lawrence Berkeley Nat. Lab., Berkeley, CA 94720 (United States)

    2009-09-01

    Direct mapping of the charge transport efficiency of polymer solar cell devices using a soft X-ray beam induced current (SoXBIC) method is described. By fabricating a polymer solar cell on an x-ray transparent substrate, we demonstrate the ability to map polymer composition and nanoscale structure within an operating solar cell device and to simultaneously measure the local charge transport efficiency via the short-circuit current. A simple model is calculated and compared to experimental SoXBIC data of a PFB:F8BT bulk-heterojunction device in order to gain greater insight into the device operation and physics.

  11. Defect detection in conducting materials using eddy current testing techniques

    Directory of Open Access Journals (Sweden)

    Brauer Hartmut

    2014-01-01

    Full Text Available Lorentz force eddy current testing (LET is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in nonmagnetic moving conductors. The LET is compared (similar testing conditions with the classical eddy current testing (ECT. Numerical FEM simulations have been performed to analyze the measurements as well as the identification of internal defects in nonmagnetic conductors. The results are compared with measurements to test the feasibility of defect identification. Finally, the use of LET measurements to estimate of the electrical conductors under test are described as well.

  12. Radiotherapy in prostate cancer. Innovative techniques and current controversies

    Energy Technology Data Exchange (ETDEWEB)

    Geinitz, Hans [Krankenhaus der Barmherzigen Schwestern, Linz (Austria). Dept. of Radiation Oncology; Linz Univ. (Austria). Medical Faculty; Roach, Mack III [California Univ., San Francisco, CA (United States). Dept. of Radiation Oncology; Van As, Nicholas (ed.) [The Institute of Cancer Research, Sutton Surrey (United Kingdom)

    2015-04-01

    Examines in detail the role of innovative radiation techniques in the management of prostate cancer, including IMRT, IGRT, BART, and modern brachytherapy. Explores a range of current controversies in patient treatment. Intended for both radiation oncologists and urologists. Radiation treatment is rapidly evolving owing to the coordinated research of physicists, engineers, computer and imaging specialists, and physicians. Today, the arsenal of ''high-precision'' or ''targeted'' radiotherapy includes multimodal imaging, in vivo dosimetry, Monte Carlo techniques for dose planning, patient immobilization techniques, intensity-modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT), biologically adapted radiotherapy (BART), quality assurance methods, novel methods of brachytherapy, and, at the far end of the scale, particle beam radiotherapy using protons and carbon ions. These approaches are like pieces of a puzzle that need to be put together to provide the prostate cancer patient with high-level optimized radiation treatment. This book examines in detail the role of the above-mentioned innovative radiation techniques in the management of prostate cancer. In addition, a variety of current controversies regarding treatment are carefully explored, including whether prophylactic treatment of the pelvic lymphatics is essential, the magnitude of the effect of dose escalation, whether a benefit accrues from hypofractionation, and what evidence exists for the superiority of protons or heavy ions. Radiotherapy in Prostate Cancer: Innovative Techniques and Current Controversies is intended for both radiation oncologists and urologists with an interest in the up-to-date capabilities of modern radiation oncology for the treatment of prostate cancer.

  13. Power electronic converters PWM strategies and current control techniques

    CERN Document Server

    Monmasson, Eric

    2013-01-01

    A voltage converter changes the voltage of an electrical power source and is usually combined with other components to create a power supply. This title is devoted to the control of static converters, which deals with pulse-width modulation (PWM) techniques, and also discusses methods for current control. Various application cases are treated. The book is ideal for professionals in power engineering, power electronics, and electric drives industries, as well as practicing engineers, university professors, postdoctoral fellows, and graduate students.

  14. Current STR-based techniques in forensic science

    Directory of Open Access Journals (Sweden)

    Phuvadol Thanakiatkrai

    2013-01-01

    Full Text Available DNA analysis in forensic science is mainly based on short tandem repeat (STR genotyping. The conventional analysis is a three-step process of DNA extraction, amplification and detection. An overview of various techniques that are currently in use and are being actively researched for STR typing is presented. The techniques are separated into STR amplification and detection. New techniques for forensic STR analysis focus on increasing sensitivity, resolution and discrimination power for suboptimal samples. These are achieved by shifting primer-binding sites, using high-fidelity and tolerant polymerases and applying novel methods to STR detection. Examples in which STRs are used in criminal investigations are provided and future research directions are discussed.

  15. Advanced experimental and numerical techniques for cavitation erosion prediction

    CERN Document Server

    Chahine, Georges; Franc, Jean-Pierre; Karimi, Ayat

    2014-01-01

    This book provides a comprehensive treatment of the cavitation erosion phenomenon and state-of-the-art research in the field. It is divided into two parts. Part 1 consists of seven chapters, offering a wide range of computational and experimental approaches to cavitation erosion. It includes a general introduction to cavitation and cavitation erosion, a detailed description of facilities and measurement techniques commonly used in cavitation erosion studies, an extensive presentation of various stages of cavitation damage (including incubation and mass loss), and insights into the contribution of computational methods to the analysis of both fluid and material behavior. The proposed approach is based on a detailed description of impact loads generated by collapsing cavitation bubbles and a physical analysis of the material response to these loads. Part 2 is devoted to a selection of nine papers presented at the International Workshop on Advanced Experimental and Numerical Techniques for Cavitation Erosion (Gr...

  16. Experimental data processing techniques by a personal computer

    International Nuclear Information System (INIS)

    Matsuura, Kiyokata; Tsuda, Kenzo; Abe, Yoshihiko; Kojima, Tsuyoshi; Nishikawa, Akira; Shimura, Hitoshi; Hyodo, Hiromi; Yamagishi, Shigeru.

    1989-01-01

    A personal computer (16-bit, about 1 MB memory) can be used at a low cost in the experimental data processing. This report surveys the important techniques on A/D and D/A conversion, display, store and transfer of the experimental data. It is also discussed the items to be considered in the software. Practical softwares programed BASIC and Assembler language are given as examples. Here, we present some techniques to get faster process in BASIC language and show that the system composed of BASIC and Assembler is useful in a practical experiment. The system performance such as processing speed and flexibility in setting operation condition will depend strongly on programming language. We have made test for processing speed by some typical programming languages; BASIC(interpreter), C, FORTRAN and Assembler. As for the calculation, FORTRAN has the best performance which is comparable to or better than Assembler even in the personal computer. (author)

  17. The development of human factors experimental evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Bong Shick; Oh, In Suk; Cha, Kyung Ho; Lee, Hyun Chul; Park, Geun Ok; Cheon, Se Woo; Suh, Sang Moon

    1997-07-01

    New human factors issues, such as evaluation of information navigation, the consideration of operator characteristics, and operator performance assessment, related to the HMI design based on VDUs are being risen. Thus, in order to solve these human factors issues, this project aims to establish the experimental technologies including the techniques for experimental design, experimental measurement, data collection and analysis, and to develop ITF (Integrated Test Facility) suitable for the experiment of HMI design evaluation. For the establish of the experimental data analysis and evaluation methodologies, we developed as the following: (1) a paradigm for human factors experimentation including experimental designs, procedures, and data analysis. (2) the methods for the assessment of operator`s mental workload (3) DAEXESS (data analysis and experiment evaluation supporting system). Also, we have established a experiment execution technologies through the preliminary experiments, such as the suitability evaluation of information display on a LSDP, the evaluation of information display on a LSDP, the evaluation of computerized operation procedure and an experiment of advanced alarm system (ADIOS). Finally, we developed the ITF including human machine simulator, telemetry system, an eye tracking system, an audio/video data measurement system, and three dimensional micro behaviour analysis system. (author). 81 refs., 68 tabs., 73 figs.

  18. A novel experimental technique of nuclear lifetime measurements

    International Nuclear Information System (INIS)

    Yuminov, O.A.; D'Arrigo, A.; Giardina, G.; Taccone, A.; Vannini, G.; Moroni, A.; Ricci, R.A.; Vannucci, L.

    1995-01-01

    In the present paper a new experimental method to measure nuclear reaction time in the 10 -15 -10 -10 s region is presented. Measurements of the lifetimes of low-lying and long-lived states of 19 F and 20 Ne decaying via α-channel were carried out with the aim of checking the feasibility of the method. The results obtained in this way are compared with the lifetimes known from different techniques. ((orig.))

  19. Eddy current techniques for super duplex stainless steel characterization

    International Nuclear Information System (INIS)

    Camerini, C.; Sacramento, R.; Areiza, M.C.; Rocha, A.; Santos, R.; Rebello, J.M.; Pereira, G.

    2015-01-01

    Super duplex stainless steel (SDSS) is a two-phase material where the microstructure consists of grains of ferrite (δ) and austenite (γ). SDSS exhibit an attractive combination of properties, such as: strength, toughness and stress corrosion cracking resistance. Nevertheless, SDSS attain these properties after a controlled solution heat treatment, leading to a similar volumetric fraction of δ and γ. Any further heat treatment, welding operation for example, can change the balance of the original phases, or may also lead to precipitation of a deleterious phase, such as sigma (σ). For these situations, the material corrosion resistance is severely impaired. In the present study, several SDSS samples with low σ phase content and non-balanced microstructure were intentionally obtained by thermally treating SDSS specimens. Electromagnetic techniques, conventional Eddy Current Testing (ECT) and Saturated Low Frequency Eddy Current (SLOFEC), were employed to characterize the SDSS samples. The results showed that ECT and SLOFEC are reliable techniques to evaluate σ phase presence in SDSS and can provide an estimation of the δ content. - Highlights: • Sigma phase precipitation, even for low amounts, dramatically affects SDSS properties. • SDSS samples were thermally treated and carefully characterized by X-Ray Diffraction. • NDT techniques detected low amounts of sigma phase in SDSS microstructure

  20. Eddy current techniques for super duplex stainless steel characterization

    Energy Technology Data Exchange (ETDEWEB)

    Camerini, C., E-mail: cgcamerini@metalmat.ufrj.br [Laboratory of Non-Destructive Testing, Corrosion and Welding, Department of Metallurgical and Materials Engineering, Federal University of Rio de Janeiro (Brazil); Sacramento, R.; Areiza, M.C.; Rocha, A. [Laboratory of Non-Destructive Testing, Corrosion and Welding, Department of Metallurgical and Materials Engineering, Federal University of Rio de Janeiro (Brazil); Santos, R. [PETROBRAS R& D Center, Rio de Janeiro (Brazil); Rebello, J.M.; Pereira, G. [Laboratory of Non-Destructive Testing, Corrosion and Welding, Department of Metallurgical and Materials Engineering, Federal University of Rio de Janeiro (Brazil)

    2015-08-15

    Super duplex stainless steel (SDSS) is a two-phase material where the microstructure consists of grains of ferrite (δ) and austenite (γ). SDSS exhibit an attractive combination of properties, such as: strength, toughness and stress corrosion cracking resistance. Nevertheless, SDSS attain these properties after a controlled solution heat treatment, leading to a similar volumetric fraction of δ and γ. Any further heat treatment, welding operation for example, can change the balance of the original phases, or may also lead to precipitation of a deleterious phase, such as sigma (σ). For these situations, the material corrosion resistance is severely impaired. In the present study, several SDSS samples with low σ phase content and non-balanced microstructure were intentionally obtained by thermally treating SDSS specimens. Electromagnetic techniques, conventional Eddy Current Testing (ECT) and Saturated Low Frequency Eddy Current (SLOFEC), were employed to characterize the SDSS samples. The results showed that ECT and SLOFEC are reliable techniques to evaluate σ phase presence in SDSS and can provide an estimation of the δ content. - Highlights: • Sigma phase precipitation, even for low amounts, dramatically affects SDSS properties. • SDSS samples were thermally treated and carefully characterized by X-Ray Diffraction. • NDT techniques detected low amounts of sigma phase in SDSS microstructure.

  1. Current techniques for the investigation of vulnerable atherosclerotic plaques

    International Nuclear Information System (INIS)

    Riou, L.; Broisat, A.; Fagret, D.; Ghezzi, C.

    2005-01-01

    Atherosclerosis is the single most important contributor to cardiovascular diseases, the leading cause of death in industrialized countries. Atherosclerosis complications such as vulnerable coronary plaque rupture or erosion result in acute coronary events, i.e. myocardial infarction and sudden death. Vulnerable plaques initially develop eccentrically without impeding on the vessel lumen and are therefore not detectable using angiography. New techniques for the investigation of vulnerable plaques are needed to identify and treat vulnerable patients. Invasive techniques require the use of intracoronary probes and are thereby not applicable to large populations of patients. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the most promising invasive modalities. They provide morphological data that could potentially be associated with a more functional approach such as thermography, elasto-graphy, or spectroscopy, Non-invasive techniques are better suited for studying larger populations of patients. Computed tomography is currently used for calcium scoring, but the biological meaning and the prognostic value of this index remain to be fully determined. Non-invasive coronary magnetic resonance imaging (MRI) faces numerous technical challenges, and it essentially provides morphological data. Molecular nuclear imaging offers a great sensitivity and the ability to provide metabolic data about atherosclerotic lesions. New potential tracers of vulnerable plaques are currently being evaluated. Nuclear Medicine should therefore play a major role in the future as a non invasive imaging modality for the assessment of vulnerable atherosclerotic plaques. (author)

  2. Thermoelectric Generation Of Current - Theoretical And Experimental Analysis

    Science.gov (United States)

    Ruciński, Adam; Rusowicz, Artur

    2017-12-01

    This paper provides some information about thermoelectric technology. Some new materials with improved figures of merit are presented. These materials in Peltier modules make it possible to generate electric current thanks to a temperature difference. The paper indicates possible applications of thermoelectric modules as interesting tools for using various waste heat sources. Some zero-dimensional equations describing the conditions of electric power generation are given. Also, operating parameters of Peltier modules, such as voltage and electric current, are analyzed. The paper shows chosen characteristics of power generation parameters. Then, an experimental stand for ongoing research and experimental measurements are described. The authors consider the resistance of a receiver placed in the electric circuit with thermoelectric elements. Finally, both the analysis of experimental results and conclusions drawn from theoretical findings are presented. Voltage generation of about 1.5 to 2.5 V for the temperature difference from 65 to 85 K was observed when a bismuth telluride thermoelectric couple (traditionally used in cooling technology) was used.

  3. Thermoelectric Generation Of Current – Theoretical And Experimental Analysis

    Directory of Open Access Journals (Sweden)

    Ruciński Adam

    2017-12-01

    Full Text Available This paper provides some information about thermoelectric technology. Some new materials with improved figures of merit are presented. These materials in Peltier modules make it possible to generate electric current thanks to a temperature difference. The paper indicates possible applications of thermoelectric modules as interesting tools for using various waste heat sources. Some zero-dimensional equations describing the conditions of electric power generation are given. Also, operating parameters of Peltier modules, such as voltage and electric current, are analyzed. The paper shows chosen characteristics of power generation parameters. Then, an experimental stand for ongoing research and experimental measurements are described. The authors consider the resistance of a receiver placed in the electric circuit with thermoelectric elements. Finally, both the analysis of experimental results and conclusions drawn from theoretical findings are presented. Voltage generation of about 1.5 to 2.5 V for the temperature difference from 65 to 85 K was observed when a bismuth telluride thermoelectric couple (traditionally used in cooling technology was used.

  4. An Experimental Evaluation of Blockage Corrections for Current Turbines

    Science.gov (United States)

    Ross, Hannah; Polagye, Brian

    2017-11-01

    Flow confinement has been shown to significantly alter the performance of turbines that extract power from water currents. These performance effects are related to the degree of constraint, defined by the ratio of turbine projected area to channel cross-sectional area. This quantity is referred to as the blockage ratio. Because it is often desirable to adjust experimental observations in water channels to unconfined conditions, analytical corrections for both wind and current turbines have been derived. These are generally based on linear momentum actuator disk theory but have been applied to turbines without experimental validation. This work tests multiple blockage corrections on performance and thrust data from a cross-flow turbine and porous plates (experimental analogues to actuator disks) collected in laboratory flumes at blockage ratios ranging between 10 and 35%. To isolate the effects of blockage, the Reynolds number, Froude number, and submergence depth were held constant while the channel width was varied. Corrected performance data are compared to performance in a towing tank at a blockage ratio of less than 5%. In addition to examining the accuracy of each correction, underlying assumptions are assessed to determine why some corrections perform better than others. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1256082 and the Naval Facilities Engineering Command (NAVFAC).

  5. Technique of experimental evaluation of cloud environment attacks detection accuracy

    Directory of Open Access Journals (Sweden)

    Sergey A. Klimachev

    2018-05-01

    Full Text Available The article is devoted to research of efficiency evaluation of IDS used for dynamic and complex organizational and technical structure computing platform guard. The components of the platform have a set of heterogeneous parameters. Analysis of existing IDS evaluation technique revealed shortcomings in justification of quantitative metrics that describe the efficiency and reliability IDS resolving. This makes if difficult to prove IDS evaluation technique. The purpose of the study is to increase IDS evaluation objectivity. To achive the purpose it is necessary to develop the correct technique, tools, experimental stand. The article proposes the results of development and approbation of the technique of IDS efficiency evaluation and software for it. The technique is based on defining of optimal set of attack detection accuracy scores. The technique and the software allow solving problems of comparative analysis of IDS that have similar functionality. As a result of the research, a number of task have been solved, including the selection of universal quantitative metrics for attack detection accuracy evaluation, the defining of summarised attack detection accuracy evaluation metric based on defining of pareto-optimal set of scores that ensure the confidentiality, integrity and accessibility of cloud environment information and information resources,  the development of a functional model,  a functional scheme and a software for cloud environment IDS research.

  6. Experimental techniques for single cell and single molecule biomechanics

    International Nuclear Information System (INIS)

    Lim, C.T.; Zhou, E.H.; Li, A.; Vedula, S.R.K.; Fu, H.X.

    2006-01-01

    Stresses and strains that act on the human body can arise either from external physical forces or internal physiological environmental conditions. These biophysical interactions can occur not only at the musculoskeletal but also cellular and molecular levels and can determine the health and function of the human body. Here, we seek to investigate the structure-property-function relationship of cells and biomolecules so as to understand their important physiological functions as well as establish possible connections to human diseases. With the recent advancements in cell and molecular biology, biophysics and nanotechnology, several innovative and state-of-the-art experimental techniques and equipment have been developed to probe the structural and mechanical properties of biostructures from the micro- down to picoscale. Some of these experimental techniques include the optical or laser trap method, micropipette aspiration, step-pressure technique, atomic force microscopy and molecular force spectroscopy. In this article, we will review the basic principles and usage of these techniques to conduct single cell and single molecule biomechanics research

  7. Principle of the electrically induced Transient Current Technique

    Science.gov (United States)

    Bronuzzi, J.; Moll, M.; Bouvet, D.; Mapelli, A.; Sallese, J. M.

    2018-05-01

    In the field of detector development for High Energy Physics, the so-called Transient Current Technique (TCT) is used to characterize the electric field profile and the charge trapping inside silicon radiation detectors where particles or photons create electron-hole pairs in the bulk of a semiconductor device, as PiN diodes. In the standard approach, the TCT signal originates from the free carriers generated close to the surface of a silicon detector, by short pulses of light or by alpha particles. This work proposes a new principle of charge injection by means of lateral PN junctions implemented in one of the detector electrodes, called the electrical TCT (el-TCT). This technique is fully compatible with CMOS technology and therefore opens new perspectives for assessment of radiation detectors performances.

  8. Applying inversion techniques to derive source currents and geoelectric fields for geomagnetically induced current calculations

    Directory of Open Access Journals (Sweden)

    J. S. de Villiers

    2014-10-01

    Full Text Available This research focuses on the inversion of geomagnetic variation field measurement to obtain source currents in the ionosphere. During a geomagnetic disturbance, the ionospheric currents create magnetic field variations that induce geoelectric fields, which drive geomagnetically induced currents (GIC in power systems. These GIC may disturb the operation of power systems and cause damage to grounded power transformers. The geoelectric fields at any location of interest can be determined from the source currents in the ionosphere through a solution of the forward problem. Line currents running east–west along given surface position are postulated to exist at a certain height above the Earth's surface. This physical arrangement results in the fields on the ground having the magnetic north and down components, and the electric east component. Ionospheric currents are modelled by inverting Fourier integrals (over the wavenumber of elementary geomagnetic fields using the Levenberg–Marquardt technique. The output parameters of the inversion model are the current strength, height and surface position of the ionospheric current system. A ground conductivity structure with five layers from Quebec, Canada, based on the Layered-Earth model is used to obtain the complex skin depth at a given angular frequency. This paper presents preliminary and inversion results based on these structures and simulated geomagnetic fields. The results show some interesting features in the frequency domain. Model parameters obtained through inversion are within 2% of simulated values. This technique has applications for modelling the currents of electrojets at the equator and auroral regions, as well as currents in the magnetosphere.

  9. Immersed transient eddy current flow metering: a calibration-free velocity measurement technique for liquid metals

    Science.gov (United States)

    Krauter, N.; Stefani, F.

    2017-10-01

    Eddy current flow meters are widely used for measuring the flow velocity of electrically conducting fluids. Since the flow induced perturbations of a magnetic field depend both on the geometry and the conductivity of the fluid, extensive calibration is needed to get accurate results. Transient eddy current flow metering has been developed to overcome this problem. It relies on tracking the position of an impressed eddy current system that is moving with the same velocity as the conductive fluid. We present an immersed version of this measurement technique and demonstrate its viability by numerical simulations and a first experimental validation.

  10. Immersed transient eddy current flow metering: a calibration-free velocity measurement technique for liquid metals

    International Nuclear Information System (INIS)

    Krauter, N; Stefani, F

    2017-01-01

    Eddy current flow meters are widely used for measuring the flow velocity of electrically conducting fluids. Since the flow induced perturbations of a magnetic field depend both on the geometry and the conductivity of the fluid, extensive calibration is needed to get accurate results. Transient eddy current flow metering has been developed to overcome this problem. It relies on tracking the position of an impressed eddy current system that is moving with the same velocity as the conductive fluid. We present an immersed version of this measurement technique and demonstrate its viability by numerical simulations and a first experimental validation. (paper)

  11. Proton current measurements using the prompt gamma ray diagnostic technique

    International Nuclear Information System (INIS)

    Leeper, R.J.; Burns, E.J.T.; Johnson, D.J.; McMurtry, W.M.

    1981-01-01

    Prompt gamma ray signals from the nuclear reaction 7 Li(p,γ) 8 Be have been used to make time resolved proton current measurements. In these measurements, the proton beam was allowed to strike cylindrical thick lithium metal targets. The time integrated proton current was measured using gamma activation of copper via the reaction 63 Cu(γ,n) 62 Cu(β+). The positron activity of the copper sample was easily measured using coincidence counting techniques. The number of 62 Cu atoms produced per proton incident on a thick Li metal target was determined with separate calibration runs performed on the Sandia 2.5 MeV Van de Graaff accelerator. The time history of the prompt gamma production was measured using six EGG NPM-54 scintillator photomultiplier combinations shielded by 96.5 cm of concrete and 5.1 cm of Pb. The use of six scintillator photomultiplier combinations was necessary to increase the statistical precision of the data. The normalization of the prompt gamma time history data with the total time integrated proton-current measurement yielded the absolute time resolved proton current on target. Data from runs performed on the Sandia Proto I accelerator will be presented

  12. Eddy current techniques for super duplex stainless steel characterization

    Science.gov (United States)

    Camerini, C.; Sacramento, R.; Areiza, M. C.; Rocha, A.; Santos, R.; Rebello, J. M.; Pereira, G.

    2015-08-01

    Super duplex stainless steel (SDSS) is a two-phase material where the microstructure consists of grains of ferrite (δ) and austenite (γ). SDSS exhibit an attractive combination of properties, such as: strength, toughness and stress corrosion cracking resistance. Nevertheless, SDSS attain these properties after a controlled solution heat treatment, leading to a similar volumetric fraction of δ and γ. Any further heat treatment, welding operation for example, can change the balance of the original phases, or may also lead to precipitation of a deleterious phase, such as sigma (σ). For these situations, the material corrosion resistance is severely impaired. In the present study, several SDSS samples with low σ phase content and non-balanced microstructure were intentionally obtained by thermally treating SDSS specimens. Electromagnetic techniques, conventional Eddy Current Testing (ECT) and Saturated Low Frequency Eddy Current (SLOFEC), were employed to characterize the SDSS samples. The results showed that ECT and SLOFEC are reliable techniques to evaluate σ phase presence in SDSS and can provide an estimation of the δ content.

  13. Nonlocal Regularized Algebraic Reconstruction Techniques for MRI: An Experimental Study

    Directory of Open Access Journals (Sweden)

    Xin Li

    2013-01-01

    Full Text Available We attempt to revitalize researchers' interest in algebraic reconstruction techniques (ART by expanding their capabilities and demonstrating their potential in speeding up the process of MRI acquisition. Using a continuous-to-discrete model, we experimentally study the application of ART into MRI reconstruction which unifies previous nonuniform-fast-Fourier-transform- (NUFFT- based and gridding-based approaches. Under the framework of ART, we advocate the use of nonlocal regularization techniques which are leveraged from our previous research on modeling photographic images. It is experimentally shown that nonlocal regularization ART (NR-ART can often outperform their local counterparts in terms of both subjective and objective qualities of reconstructed images. On one real-world k-space data set, we find that nonlocal regularization can achieve satisfactory reconstruction from as few as one-third of samples. We also address an issue related to image reconstruction from real-world k-space data but overlooked in the open literature: the consistency of reconstructed images across different resolutions. A resolution-consistent extension of NR-ART is developed and shown to effectively suppress the artifacts arising from frequency extrapolation. Both source codes and experimental results of this work are made fully reproducible.

  14. Remote welding and cutting techniques for fusion experimental reactors

    International Nuclear Information System (INIS)

    Onozuka, M.; Ishide, T.; Oda, Y.; Nagaoka, E.; Ue, K.; Kamei, H.

    1995-01-01

    Experimental investigation of the YAG laser cutting/welding and plasma gouging techniques has been conducted to examine their suitability for remote maintenance systems in future fusion experimental reactors. Using a hybrid beam coupling system, two laser beams of 500W and 740W powers were successfully combined to provide a 1,240W beam power. The combined laser was transmitted through the optical fiber for cutting and welding. The transmission loss for the beams is in the range of 13% to 14%, which is low. As for plasma gouging, the shallow gouging made a groove measuring 10 mm in width and 4 mm in depth on the stainless steel plates at a traversing speed of 75 cm/min, while the deep gouging made a groove of 12 mm in width and 7.5 mm in depth at a traversing speed of 50 cm/min. In addition, it was found that the shallow gouging did not leave byproducts from the material, providing a clean surface. Based on the findings, it is shown that the YAG laser cutting/welding and plasma gouging techniques can be us3ed for remote welding and cutting in future fusion experimental reactors

  15. Remote welding and cutting techniques for fusion experimental reactors

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Ishide, T.; Oda, Y.; Nagaoka, E.; Ue, K.; Kamei, H. [Mitsubishi Heavy Industries, Ltd., Yokohama (Japan)

    1995-12-31

    Experimental investigation of the YAG laser cutting/welding and plasma gouging techniques has been conducted to examine their suitability for remote maintenance systems in future fusion experimental reactors. Using a hybrid beam coupling system, two laser beams of 500W and 740W powers were successfully combined to provide a 1,240W beam power. The combined laser was transmitted through the optical fiber for cutting and welding. The transmission loss for the beams is in the range of 13% to 14%, which is low. As for plasma gouging, the shallow gouging made a groove measuring 10 mm in width and 4 mm in depth on the stainless steel plates at a traversing speed of 75 cm/min, while the deep gouging made a groove of 12 mm in width and 7.5 mm in depth at a traversing speed of 50 cm/min. In addition, it was found that the shallow gouging did not leave byproducts from the material, providing a clean surface. Based on the findings, it is shown that the YAG laser cutting/welding and plasma gouging techniques can be us3ed for remote welding and cutting in future fusion experimental reactors.

  16. Progress in wind tunnel experimental techniques for wind turbine?

    Institute of Scientific and Technical Information of China (English)

    Jingping XIAO; Li CHEN; Qiang WANG; Qiao WANG

    2016-01-01

    Based on the unsteady aerodynamics experiment (UAE) phase VI and the model experiment in controlled conditions (MEXICO) projects and the related research carried out in China Aerodynamic Research and Development Center (CARDC), the recent progress in the wind tunnel experimental techniques for the wind turbine is sum-marized. Measurement techniques commonly used for di?erent types of wind tunnel ex-periments for wind turbine are reviewed. Important research achievements are discussed, such as the wind tunnel disturbance, the equivalence of the airfoil in?ow condition, the three-dimensional (3D) e?ect, the dynamic in?ow in?uence, the ?ow ?eld structure, and the vortex induction. The corresponding research at CARDC and some ideas on the large wind turbine are also introduced.

  17. Experimental comparison of particle interaction measurement techniques using optical traps

    International Nuclear Information System (INIS)

    Koehler, Timothy P.; Grillet, Anne Mary; Brotherton, Christopher M.; Molecke, Ryan A.

    2008-01-01

    Optical tweezers has become a powerful and common tool for sensitive determination of electrostatic interactions between colloidal particles. Recently, two techniques, 'blinking' tweezers and direct force measurements, have become increasingly prevalent in investigations of inter-particle potentials. The 'blinking' tweezers method acquires physical statistics of particle trajectories to determine drift velocities, diffusion coefficients, and ultimately colloidal forces as a function of the center-center separation of two particles. Direct force measurements monitor the position of a particle relative to the center of an optical trap as the separation distance between two continuously trapped particles is gradually decreased. As the particles near each other, the displacement from the trap center for each particle increases proportional to the inter-particle force. Although commonly employed in the investigation of interactions of colloidal particles, there exists no direct comparison of these experimental methods in the literature. In this study, an experimental apparatus was developed capable of performing both methods and is used to quantify electrostatic potentials between particles in several particle/solvent systems. Comparisons are drawn between the experiments conducted using the two measurement techniques, theory, and existing literature. Forces are quantified on the femto-Newton scale and results agree well with literature values

  18. Advances in Current Rating Techniques for Flexible Printed Circuits

    Science.gov (United States)

    Hayes, Ron

    2014-01-01

    Twist Capsule Assemblies are power transfer devices commonly used in spacecraft mechanisms that require electrical signals to be passed across a rotating interface. Flexible printed circuits (flex tapes, see Figure 2) are used to carry the electrical signals in these devices. Determining the current rating for a given trace (conductor) size can be challenging. Because of the thermal conditions present in this environment the most appropriate approach is to assume that the only means by which heat is removed from the trace is thru the conductor itself, so that when the flex tape is long the temperature rise in the trace can be extreme. While this technique represents a worst-case thermal situation that yields conservative current ratings, this conservatism may lead to overly cautious designs when not all traces are used at their full rated capacity. A better understanding of how individual traces behave when they are not all in use is the goal of this research. In the testing done in support of this paper, a representative flex tape used for a flight Solar Array Drive Assembly (SADA) application was tested by energizing individual traces (conductors in the tape) in a vacuum chamber and the temperatures of the tape measured using both fine-gauge thermocouples and infrared thermographic imaging. We find that traditional derating schemes used for bundles of wires do not apply for the configuration tested. We also determine that single active traces located in the center of a flex tape operate at lower temperatures than those on the outside edges.

  19. Wall conditioning for ITER: Current experimental and modeling activities

    Energy Technology Data Exchange (ETDEWEB)

    Douai, D., E-mail: david.douai@cea.fr [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Kogut, D. [CEA, IRFM, Association Euratom-CEA, 13108 St. Paul lez Durance (France); Wauters, T. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Brezinsek, S. [FZJ, Institut für Energie- und Klimaforschung Plasmaphysik, 52441 Jülich (Germany); Hagelaar, G.J.M. [Laboratoire Plasma et Conversion d’Energie, UMR5213, Toulouse (France); Hong, S.H. [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of); Lomas, P.J. [CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Lyssoivan, A. [LPP-ERM/KMS, Association Belgian State, 1000 Brussels (Belgium); Nunes, I. [Associação EURATOM-IST, Instituto de Plasmas e Fusão Nuclear, 1049-001 Lisboa (Portugal); Pitts, R.A. [ITER International Organization, F-13067 St. Paul lez Durance (France); Rohde, V. [Max-Planck-Institut für Plasmaphysik, 85748 Garching (Germany); Vries, P.C. de [ITER International Organization, F-13067 St. Paul lez Durance (France)

    2015-08-15

    Wall conditioning will be required in ITER to control fuel and impurity recycling, as well as tritium (T) inventory. Analysis of conditioning cycle on the JET, with its ITER-Like Wall is presented, evidencing reduced need for wall cleaning in ITER compared to JET–CFC. Using a novel 2D multi-fluid model, current density during Glow Discharge Conditioning (GDC) on the in-vessel plasma-facing components (PFC) of ITER is predicted to approach the simple expectation of total anode current divided by wall surface area. Baking of the divertor to 350 °C should desorb the majority of the co-deposited T. ITER foresees the use of low temperature plasma based techniques compatible with the permanent toroidal magnetic field, such as Ion (ICWC) or Electron Cyclotron Wall Conditioning (ECWC), for tritium removal between ITER plasma pulses. Extrapolation of JET ICWC results to ITER indicates removal comparable to estimated T-retention in nominal ITER D:T shots, whereas GDC may be unattractive for that purpose.

  20. Experimental program for development and evaluation of nondestructive assay techniques for plutonium holdup

    International Nuclear Information System (INIS)

    Brumbach, S.B.

    1977-05-01

    An outline is presented for an experimental program to develop and evaluate nondestructive assay techniques applicable to holdup measurement in plutonium-containing fuel fabrication facilities. The current state-of-the-art in holdup measurements is reviewed. Various aspects of the fuel fabrication process and the fabrication facility are considered for their potential impact on holdup measurements. The measurement techniques considered are those using gamma-ray counting, neutron counting, and temperature measurement. The advantages and disadvantages of each technique are discussed. Potential difficulties in applying the techniques to holdup measurement are identified. Experiments are proposed to determine the effects of such problems as variation in sample thickness, in sample distribution, and in background radiation. These experiments are also directed toward identification of techniques most appropriate to various applications. Also proposed are experiments to quantify the uncertainties expected for each measurement

  1. Techniques for Improving the Accuracy of 802.11 WLAN-Based Networking Experimentation

    Directory of Open Access Journals (Sweden)

    Portoles-Comeras Marc

    2010-01-01

    Full Text Available Wireless networking experimentation research has become highly popular due to both the frequent mismatch between theory and practice and the widespread availability of low-cost WLAN cards. However, current WLAN solutions present a series of performance issues, sometimes difficult to predict in advance, that may compromise the validity of the results gathered. This paper surveys recent literature dealing with such issues and draws attention on the negative results of starting experimental research without properly understanding the tools that are going to be used. Furthermore, the paper details how a conscious assessment strategy can prevent placing wrong assumptions on the hardware. Indeed, there are numerous techniques that have been described throughout the literature that can be used to obtain a deeper understanding of the solutions that have been adopted. The paper surveys these techniques and classifies them in order to provide a handful reference for building experimental setups from which accurate measurements may be obtained.

  2. Laser-welded ureteral anastomoses: experimental studies with three techniques.

    Science.gov (United States)

    Gürpinar, T; Gürer, S; Kattan, M W; Wang, L; Griffith, D P

    1996-01-01

    Tissue welding with laser energy is a new technique for reconstructive surgery. The potential advantages of laser welding are (a) lack of foreign body reaction, (b) decreased operative time, (c) less tissue manipulation, and (d) effective union of tissues equivalent to sutured anastomoses. We have performed ureteral anastomoses in adult mongrel dogs using a KTP 532 nm laser at an intensity of 1.4 W. Multiple "spot welds" of 1-s duration were utilized in a single layer anastomosis. Laser-welded anastomoses were performed with and without protein solder (33% and 50% human albumin) and were compared to sutured anastomoses. The laser-welded anastomoses required less operative time and provided bursting pressure levels similar to those of traditional sutured anastomoses. There was no advantage or disadvantage to the addition of human albumin as a solder in these experimental studies.

  3. ESR dating: is it still an 'experimental' technique?

    International Nuclear Information System (INIS)

    Skinner, A.R.

    2000-01-01

    Nearly 25 years ago, Motoji Ikeya demonstrated the potential of ESR dating. From a single substance (stalagmitic carbonate) and a single site (Akiyoshi Cavern), the field has grown to include materials from all over the world and time periods from a few thousand years ago to several million years ago. A vigorous program of instrumentation development has increased the precision of measurements as well as opening up new ways of collecting and interpreting spectra. Yet there are still references to ESR dating as an 'experimental' technique, one which cannot be trusted to produce dates that are accurate or precise. This paper discusses areas for which this is true and suggests what should be done to convince skeptics. Other areas for which the evidence suggests that ESR is at least as reliable as 'standard' methods will also be covered

  4. Experimental Determination of Bed Conditions in Concentrated Pyroclastic Density Currents

    Science.gov (United States)

    Winner, A.; Ferrier, K.; Dufek, J.

    2016-12-01

    Pyroclastic density currents (PDCs) are ground-hugging mixtures of hot gas and rock that can reach temperatures > 800 oC and speeds of 200 m/s. These flows are capable of eroding and entraining the underlying bed material into the flow, which can strongly influence flow momentum, runout distance, and hazards associated with PDCs. However, the mechanism of erosion remains poorly constrained, with proposed mechanisms including under-pressure following the head of the fluidized current, force chain enhanced stresses at the bed, and discrete particle impacts and friction. The interactions between PDCs and the bed have been difficult to observe in the field, as their infrequent occurrence, opacity, and hostile environment make real-time measurement difficult. This study is aimed at obtaining a better understanding of the interactions between PDCs and the bed through a quantitative analysis of bed forces. Our experimental apparatus consists of a rotating cylindrical flume of radius 22 cm, within which gas-rich granular material flows along the interior of the cylinder as it rotates. By using a rotating cylinder, we are able to simulate long-duration flows, allowing us to observe impact forces at the bed over timescales comparable to the flow duration of natural PDCs. To measure the distribution and evolution of forces imparted by the flow on the bed, we constructed a cylindrical insert with a non-erodible bed in which we embedded force sensor arrays parallel and perpendicular to the direction of flow. To measure the forces felt by the particles in the flow, we added "smart particles" 25 to 50 mm in diameter to the flow. Each smart particle contains a three-axis accelerometer and a micro SD card enclosed in a spherical plastic casing, and possesses a density similar to that of the pumice in the experimental flow. Each smart particle also contains a three-axis magnetometer which permits its location to be tracked by means of a unique applied magnetic field. Ultimately

  5. Novel Experimental Techniques to Investigate Wellbore Damage Mechanisms

    Science.gov (United States)

    Choens, R. C., II; Ingraham, M. D.; Lee, M.; Dewers, T. A.

    2017-12-01

    A new experimental technique with unique geometry is presented investigating deformation of simulated boreholes using standard axisymmetric triaxial deformation equipment. The Sandia WEllbore SImulation, SWESI, geometry, uses right cylinders of rock 50mm in diameter and 75mm in length. A 11.3mm hole is drilled perpendicular to the axis of the cylinder in the center of the sample to simulate a borehole. The hole is covered with a solid metal cover, and sealed with polyurethane. The metal cover can be machined with a high-pressure port to introduce different fluid chemistries into the borehole at controlled pressures. Samples are deformed in a standard load frame under confinement, allowing for a broad range of possible stresses, load paths, and temperatures. Experiments in this study are loaded to the desired confining pressure, then deformed at a constant axial strain rate or 10-5 sec-1. Two different suites of experiments are conducted in this study on sedimentary and crystalline rock types. The first series of experiments are conducted on Mancos Shale, a finely laminated transversely isotropic rock. Samples are cored at three different orientations to the laminations. A second series of experiments is conducted on Sierra White granite with different fluid chemistries inside the borehole. Numerical modelling and experimental observations including CT-microtomography demonstrate that stresses are concentrated around the simulated wellbore and recreate wellbore deformation mechanisms. Borehole strength and damage development is dependent on anisotropy orientation and fluid chemistry. Observed failure geometries, particularly for Mancos shale, can be highly asymmetric. These results demonstrate uncertainties in in situ stresses measurements using commonly-applied borehole breakout techniques in complicated borehole physico-chemical environments. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering

  6. Detection of localized damage by eddy currents technique

    Directory of Open Access Journals (Sweden)

    Aoukili A.

    2014-01-01

    Full Text Available Non destructive evaluation techniques based on eddy currents (EC are largely used for quality control of the castings in a lot of industries. The principle of detection by EC consists in using an adequate inductive coil to generate them by a variable magnetic field, and measuring their effects by using one or several sensors. These effects result from the interaction between the induced magnetic field and the excited conductive material. A local variation of the physical properties or geometry of the tested sample, due to a singularity or a flaw, causes a modification of the EC distribution, enabling thus detection. In order to optimize the capacity of defect revealing by means of EC based probes, an accurate modelling of the problem is essential. This can be used to perform simulation of the EC distribution under different circumstances and to analyze the EC sensitivity to the various implicated parameters. In this work, the modelling of EC is made by using the finite element method. Using a B-scan strategy was used, detection of a small defect having the shape of an open cavity is shown to be correctly indicated via monitoring variations of the induced voltage in the receiver coil.

  7. Biofilms and mechanics: a review of experimental techniques and findings

    International Nuclear Information System (INIS)

    Gordon, Vernita D; Davis-Fields, Megan; Kovach, Kristin; Rodesney, Christopher A

    2017-01-01

    Biofilms are developmentally-dynamic communities of sessile microbes that adhere to each other and, often, to other structures in their environment. The cohesive mechanical forces binding microbes to each other confer mechanical and structural stability on the biofilm and give rise to biofilm viscoelasticity. The adhesive mechanical forces binding microbes to other structures in their environment can promote biofilm initiation and mechanosensing that leads to changes in biological activity. Thus, physical mechanics is intrinsic to characteristics that distinguish biofilms from free-swimming or free-floating microbes in liquid culture. However, very little is known about the specifics of what mechanical traits characterize different types of biofilms at different stages of development. Even less is known about how mechanical inputs impact microbial biology and how microbes can adjust their mechanical coupling to, and interaction with, their environment. These knowledge gaps arise, in part, from the challenges associated with experimental measurements of microbial and biofilm biomechanics. Here, we review extant experimental techniques and their most-salient findings to date. At the end of this review we indicate areas where significant advances in the state-of-the art are heading. (topical review)

  8. Biofilms and mechanics: a review of experimental techniques and findings

    Science.gov (United States)

    Gordon, Vernita D.; Davis-Fields, Megan; Kovach, Kristin; Rodesney, Christopher A.

    2017-06-01

    Biofilms are developmentally-dynamic communities of sessile microbes that adhere to each other and, often, to other structures in their environment. The cohesive mechanical forces binding microbes to each other confer mechanical and structural stability on the biofilm and give rise to biofilm viscoelasticity. The adhesive mechanical forces binding microbes to other structures in their environment can promote biofilm initiation and mechanosensing that leads to changes in biological activity. Thus, physical mechanics is intrinsic to characteristics that distinguish biofilms from free-swimming or free-floating microbes in liquid culture. However, very little is known about the specifics of what mechanical traits characterize different types of biofilms at different stages of development. Even less is known about how mechanical inputs impact microbial biology and how microbes can adjust their mechanical coupling to, and interaction with, their environment. These knowledge gaps arise, in part, from the challenges associated with experimental measurements of microbial and biofilm biomechanics. Here, we review extant experimental techniques and their most-salient findings to date. At the end of this review we indicate areas where significant advances in the state-of-the art are heading.

  9. Maternal hypothyroidism: An overview of current experimental models.

    Science.gov (United States)

    Ghanbari, Mahboubeh; Ghasemi, Asghar

    2017-10-15

    Maternal hypothyroidism (MH) is the most common cause of transient congenital hypothyroidism. Different animal models are used for assessing developmental effects of MH in offspring. The severity and status of hypothyroidism in animal models must be a reflection of the actual conditions in humans. To obtain comparable results with different clinical conditions, which lead to MH in humans, several factors have been suggested for researchers to consider before designing the experimental models. Regarding development of fetal body systems during pregnancy, interference at different times provides different results and the appropriate time for induction of hypothyroidism should be selected based on accurate time of development of the system under assessment. Other factors that should be taken into consideration include, physiological and biochemical differences between humans and other species, thyroid hormone-independent effects of anti-thyroid drugs, circadian rhythms in TSH secretion, sex differences, physical and psychological stress. This review addresses essential guidelines for selecting and managing the optimal animal model for MH as well as discussing the pros and cons of currently used models. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Respiratory gated radiotherapy: current techniques and potential benefits

    International Nuclear Information System (INIS)

    Giraud, P.; Campana, F.; Rosenwald, J.C.; Cosset, J.M.; Reboul, F.; Garcia, R.; Clippe, S.; Carrie, C.; Dubray, B.

    2003-01-01

    Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. These techniques presently investigated in several medical centers worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. Physical, technical and physiological questions still remain to be answered. This paper describes the most frequently used gated techniques and the main published clinical reports on the use of respiration-gated radiotherapy in order to evaluate the impact of these techniques. (author)

  11. Experimental validation of incomplete data CT image reconstruction techniques

    International Nuclear Information System (INIS)

    Eberhard, J.W.; Hsiao, M.L.; Tam, K.C.

    1989-01-01

    X-ray CT inspection of large metal parts is often limited by x-ray penetration problems along many of the ray paths required for a complete CT data set. In addition, because of the complex geometry of many industrial parts, manipulation difficulties often prevent scanning over some range of angles. CT images reconstructed from these incomplete data sets contain a variety of artifacts which limit their usefulness in part quality determination. Over the past several years, the authors' company has developed 2 new methods of incorporating a priori information about the parts under inspection to significantly improve incomplete data CT image quality. This work reviews the methods which were developed and presents experimental results which confirm the effectiveness of the techniques. The new methods for dealing with incomplete CT data sets rely on a priori information from part blueprints (in electronic form), outer boundary information from touch sensors, estimates of part outer boundaries from available x-ray data, and linear x-ray attenuation coefficients of the part. The two methods make use of this information in different fashions. The relative performance of the two methods in detecting various flaw types is compared. Methods for accurately registering a priori information with x-ray data are also described. These results are critical to a new industrial x-ray inspection cell built for inspection of large aircraft engine parts

  12. Application of numerical analysis techniques to eddy current testing for steam generator tubes

    International Nuclear Information System (INIS)

    Morimoto, Kazuo; Satake, Koji; Araki, Yasui; Morimura, Koichi; Tanaka, Michio; Shimizu, Naoya; Iwahashi, Yoichi

    1994-01-01

    This paper describes the application of numerical analysis to eddy current testing (ECT) for steam generator tubes. A symmetrical and three-dimensional sinusoidal steady state eddy current analysis code was developed. This code is formulated by future element method-boundary element method coupling techniques, in order not to regenerate the mesh data in the tube domain at every movement of the probe. The calculations were carried out under various conditions including those for various probe types, defect orientations and so on. Compared with the experimental data, it was shown that it is feasible to apply this code to actual use. Furthermore, we have developed a total eddy current analysis system which consists of an ECT calculation code, an automatic mesh generator for analysis, a database and display software for calculated results. ((orig.))

  13. Experimental study of blockage of monochromatic waves by counter currents

    NARCIS (Netherlands)

    Suastika, I.K.

    1999-01-01

    Blockage of waves by a current can occur if waves are propagating on a spatially varying opposing current in which the velocity is increasing in the wave propagation direction. The ongoing waves become shorter and steeper while they are propagating against the current. Blocking occurs at the

  14. Experimental observations of the tearing of an electron current sheet

    International Nuclear Information System (INIS)

    Gekelman, W.; Pfister, H.

    1988-01-01

    A neutral magnetic sheet, in which the current is carried mainly by the electrons, is set up in a laboratory plasma. By forcing the current through a thin slot, the ratio of the length to height t of the sheet may be varied; the current is observed to tear when tapprox. >30. The structure of the magnetic islands and their associated currents is fully three dimensional, although a linear two-dimensional theory gives a very good estimate of the tearing mode growth time. Tearing is accompanied by the generation of significant Hall currents, and magnetic disturbances are observed to propagate at the whistler wave speed

  15. Fundamentals of functional imaging I: current clinical techniques.

    Science.gov (United States)

    Luna, A; Martín Noguerol, T; Mata, L Alcalá

    2018-05-01

    Imaging techniques can establish a structural, physiological, and molecular phenotype for cancer, which helps enable accurate diagnosis and personalized treatment. In recent years, various imaging techniques that make it possible to study the functional characteristics of tumors quantitatively and reproducibly have been introduced and have become established in routine clinical practice. Perfusion studies enable us to estimate the microcirculation as well as tumor angiogenesis and permeability using ultrafast dynamic acquisitions with ultrasound, computed tomography, or magnetic resonance (MR) imaging. Diffusion-weighted sequences now form part of state-of-the-art MR imaging protocols to evaluate oncologic lesions in any anatomic location. Diffusion-weighted imaging provides information about the occupation of the extracellular and extravascular space and indirectly estimates the cellularity and apoptosis of tumors, having demonstrated its relation with biologic aggressiveness in various tumor lines and its usefulness in the evaluation of the early response to systemic and local targeted therapies. Another tool is hydrogen proton MR spectroscopy, which is used mainly in the study of the metabolic characteristics of brain tumors. However, the complexity of the technique and its lack of reproducibility have limited its clinical use in other anatomic areas, although much experience with the use of this technique in the assessment of prostate and breast cancers as well as liver lesions has also accumulated. This review analyzes the imaging techniques that make it possible to evaluate the physiological and molecular characteristics of cancer that have already been introduced into clinical practice, such as techniques that evaluate angiogenesis through dynamic acquisitions after the administration of contrast material, diffusion-weighted imaging, or hydrogen proton MR spectroscopy, as well as their principal applications in oncology. Copyright © 2018 SERAM. Publicado

  16. Current trends in nuclear borehole logging techniques for elemental analysis

    International Nuclear Information System (INIS)

    1988-06-01

    This report is the result of a consultants' meeting organized by the IAEA and held in Ottawa, Canada, 2-6 November 1987 in order to assess the present technical status of nuclear borehole logging techniques, to find out the well established applications and the development trends. It contains a summary report giving a comprehensive overview of the techniques and applications and a collection of research papers describing work done in industrial institutes. A separate abstract was prepared for each of these 9 papers. Refs, figs and tabs

  17. Experimental Analysis of Temperature Differences During Implant Site Preparation: Continuous Drilling Technique Versus Intermittent Drilling Technique.

    Science.gov (United States)

    Di Fiore, Adolfo; Sivolella, Stefano; Stocco, Elena; Favero, Vittorio; Stellini, Edoardo

    2018-02-01

    Implant site preparation through drilling procedures may cause bone thermonecrosis. The aim of this in vitro study was to evaluate, using a thermal probe, overheating at implant sites during osteotomies through 2 different drilling methods (continuous drilling technique versus intermittent drilling technique) using irrigation at different temperatures. Five implant sites 13 mm in length were performed on 16 blocks (fresh bovine ribs), for a total of 80 implant sites. The PT-100 thermal probe was positioned 5 mm from each site. Two physiological refrigerant solutions were used: one at 23.7°C and one at 6.0°C. Four experimental groups were considered: group A (continuous drilling with physiological solution at 23.7°C), group B (intermittent drilling with physiological solution at 23.7°C), group C (continuous drilling with physiological solution at 6.0°C), and group D (intermittent drilling with physiological solution at 6.0°C). The Wilcoxon rank-sum test (2-tailed) was used to compare groups. While there was no difference between group A and group B (W = 86; P = .45), statistically significant differences were observed between experimental groups A and C (W = 0; P =.0001), B and D (W = 45; P =.0005), and C and D (W = 41; P = .003). Implant site preparation did not affect the overheating of the bone. Statistically significant differences were found with the refrigerant solutions. Using both irrigating solutions, bone temperature did not exceed 47°C.

  18. First principle leakage current reduction technique for CMOS devices

    CSIR Research Space (South Africa)

    Tsague, HD

    2015-12-01

    Full Text Available This paper presents a comprehensive study of leakage reduction techniques applicable to CMOS based devices. In the process, mathematical equations that model the power-performance trade-offs in CMOS logic circuits are presented. From those equations...

  19. Molecular techniques for MRSA typing: current issues and perspectives

    Directory of Open Access Journals (Sweden)

    P. A. Trindade

    Full Text Available Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially as to therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE, techniques involving polymerase chain reaction and multilocus sequence typing (MLST. Repetitive DNA Sequence PCR (rep-PCR may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST, are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose.

  20. Molecular techniques for MRSA typing: current issues and perspectives

    Directory of Open Access Journals (Sweden)

    Trindade P. A.

    2003-01-01

    Full Text Available Staphylococcus aureus has long been recognised as an important pathogen in human disease. Serious staphylococcal infections can frequently occur in inpatients and may lead to dire consequences, especially as to therapy with antimicrobial agents. The increase in the frequency of Methicillin-Resistant Staphylococcus aureus (MRSA as the causal agent of nosocomial infection and the possibility of emergence of resistance to vancomycin demands a quick and trustworthy characterization of isolates and identification of clonal spread within hospitals. Enough information must be generated to permit the implementation of appropriate measures for control of infection, so that outbreaks can be contained. Molecular typing techniques reviewed in this manuscript include: plasmid profile analysis, analysis of chromosomal DNA after enzymatic restriction, Southern blotting, pulsed field gel electrophoresis (PFGE, techniques involving polymerase chain reaction and multilocus sequence typing (MLST. Repetitive DNA Sequence PCR (rep-PCR may be used for screening due to its practicality, low cost and reproducibility. Because of its high discriminatory power Pulsed-Field Gel Electrophoresis (PFGE still remains the gold standard for MRSA typing. New techniques with higher reproducibility and discriminatory power, such as Multi-Locus Sequence Typing (MLST, are appearing. These are mostly useful for global epidemiology studies. Molecular typing techniques are invaluable tools for the assessment of putative MRSA outbreaks and so should be extensively used for this purpose.

  1. Experimental Observation of a Current-Driven Instability in a Neutral Electron-Positron Beam

    Science.gov (United States)

    Warwick, J.; Dzelzainis, T.; Dieckmann, M. E.; Schumaker, W.; Doria, D.; Romagnani, L.; Poder, K.; Cole, J. M.; Alejo, A.; Yeung, M.; Krushelnick, K.; Mangles, S. P. D.; Najmudin, Z.; Reville, B.; Samarin, G. M.; Symes, D. D.; Thomas, A. G. R.; Borghesi, M.; Sarri, G.

    2017-11-01

    We report on the first experimental observation of a current-driven instability developing in a quasineutral matter-antimatter beam. Strong magnetic fields (≥1 T ) are measured, via means of a proton radiography technique, after the propagation of a neutral electron-positron beam through a background electron-ion plasma. The experimentally determined equipartition parameter of ɛB≈10-3 is typical of values inferred from models of astrophysical gamma-ray bursts, in which the relativistic flows are also expected to be pair dominated. The data, supported by particle-in-cell simulations and simple analytical estimates, indicate that these magnetic fields persist in the background plasma for thousands of inverse plasma frequencies. The existence of such long-lived magnetic fields can be related to analog astrophysical systems, such as those prevalent in lepton-dominated jets.

  2. Experimental Observation of a Current-Driven Instability in a Neutral Electron-Positron Beam.

    Science.gov (United States)

    Warwick, J; Dzelzainis, T; Dieckmann, M E; Schumaker, W; Doria, D; Romagnani, L; Poder, K; Cole, J M; Alejo, A; Yeung, M; Krushelnick, K; Mangles, S P D; Najmudin, Z; Reville, B; Samarin, G M; Symes, D D; Thomas, A G R; Borghesi, M; Sarri, G

    2017-11-03

    We report on the first experimental observation of a current-driven instability developing in a quasineutral matter-antimatter beam. Strong magnetic fields (≥1  T) are measured, via means of a proton radiography technique, after the propagation of a neutral electron-positron beam through a background electron-ion plasma. The experimentally determined equipartition parameter of ε_{B}≈10^{-3} is typical of values inferred from models of astrophysical gamma-ray bursts, in which the relativistic flows are also expected to be pair dominated. The data, supported by particle-in-cell simulations and simple analytical estimates, indicate that these magnetic fields persist in the background plasma for thousands of inverse plasma frequencies. The existence of such long-lived magnetic fields can be related to analog astrophysical systems, such as those prevalent in lepton-dominated jets.

  3. Current control design for three-phase grid-connected inverters using a pole placement technique based on numerical models

    OpenAIRE

    Citro, Costantino; Gavriluta, Catalin; Nizak Md, H. K.; Beltran, H.

    2012-01-01

    This paper presents a design procedure for linear current controllers of three-phase grid-connected inverters. The proposed method consists in deriving a numerical model of the converter by using software simulations and applying the pole placement technique to design the controller with the desired performances. A clear example on how to apply the technique is provided. The effectiveness of the proposed design procedure has been verified through the experimental results obtained with ...

  4. Bulbar urethroplasty using the dorsal approach: current techniques

    Directory of Open Access Journals (Sweden)

    Barbagli Guido

    2003-01-01

    Full Text Available INTRODUCTION: The use of flaps or grafts is mandatory in patients with longer and complex strictures. In 1995-96 we described a new dorsal onlay graft urethroplasty. Over time, our original technique was better defined and changed. Now this procedure (also named Barbagli technique has been greeted with a fair amount of enthusiasm in Europe and in the United States. SURGICAL TECHNIQUE: The patient is placed in normal lithotomy position, and a midline perineo-scrotal incision is made. The bulbar urethra is then free from the bulbo-cavernous muscles, and is dissected from the corpora cavernosa. The urethra is completely mobilized from the corpora cavernosa, it is rotated 180 degrees, and is incised along its dorsal surface. The graft (preputial skin or buccal mucosa or the flap is fixed and quilted to the tunica albuginea of the corporal bodies. The right mucosal margin of the opened urethra is sutured to the right side of the patch-graft. The urethra is rotated back into its original position. The left urethral margin is sutured to the left side of the patch graft and to the corporal bodies, and the grafted area is entirely covered by the urethral plate. The bulbo-cavernous muscles are approximated over the grafted area. A 16F silicone Foley catheter is left in place. COMMENTS: Dorsal onlay graft urethroplasty is a versatile procedure that may be combined with various substitute materials like preputial skin, buccal mucosa grafts or pedicled flaps.

  5. Current experimental situation in heavy-ion reactions

    International Nuclear Information System (INIS)

    Scott, D.K.

    1978-06-01

    A detailed survey of the present experimental situation in heavy-ion physics is presented. The discussion begins by considering the simple excitation of discrete states in elastic scattering, transfer, and compound-nucleus reactions; it then turns to more drastic perturbations of the nucleus high in the continuum through fusion, fission, and deeply inelastic scattering, and concludes with the (possibly) limiting asymptotic phenomena of relativistic heavy-ion collisions. 138 figures, 5 tables, 451 references

  6. Chest trauma in children: current imaging guidelines and techniques.

    LENUS (Irish Health Repository)

    Moore, Michael A

    2011-09-01

    Given the heterogeneous nature of pediatric chest trauma, the optimal imaging approach is tailored to the specific patient. Chest radiography remains the most important imaging modality for initial triage. The decision to perform a chest computed tomography scan should be based on the nature of the trauma, the child\\'s clinical condition, and the initial radiographic findings, taking the age-related pretest probabilities of serious injury into account. The principles of as low as reasonably achievable and Image Gently should be followed. The epidemiology and pathophysiology, imaging techniques, characteristic findings, and evidence-based algorithms for pediatric chest trauma are discussed.

  7. Surface inspection technique with an eddy current testing array probe

    International Nuclear Information System (INIS)

    Nishimizu, Akira; Endo, Hisashi; Tooma, Masahiro; Otani, Kenichi; Ouchi, Hirofumi; Yoshida, Isao; Nonaka, Yoshio

    2010-01-01

    An eddy current testing (ECT) system has been developed for inspecting weld surfaces of components in the reactor pressure vessel of nuclear plants. The system can be applied to curved surfaces with an ECT array probe, it can discriminate flaws from other signal factors by using a combination of arrayed coils signal-phase. The system is applied to a mock-up of core internal components and the signal discrimination using the signal-phase clearly separated flaw and noise signals. (author)

  8. Alternating current techniques for corrosion monitoring in water reactor systems

    International Nuclear Information System (INIS)

    Isaacs, H.S.; Weeks, J.R.

    1977-01-01

    Corrosion in both nuclear and fossil fueled steam generators is generally a consequence of the presence of aggressive impurities introduced into the coolant system through condenser leakage. The impurities concentrate in regions of the steam generator protected from coolant flow, in crevices or under deposited corrosion products and adjacent to heat transfer surfaces. These three factors, the aggressive impurity, crevice type areas and heat transfer surfaces appear to be the requirements for the onset of rapid corrosion. Under conditions where coolant impurities do not concentrate the corrosion rates are low, easily measured and can be accounted for by allowances in the design of the steam generator. Rapid corrosion conditions cannot be designed for and must be suppressed. The condition of the surfaces when rapid corrosion develops must be markedly different from those during normal operation and these changes should be observable using electrochemical techniques. This background formed the basis of a design of a corrosion monitoring device, work on which was initiated at BNL. The basic principles of the technique are described. The object of the work is to develop a corrosion monitoring device which can be operated with PWR steam generator secondary coolant feed water

  9. Skeletal muscle proteomics: current approaches, technical challenges and emerging techniques

    LENUS (Irish Health Repository)

    Ohlendieck, Kay

    2011-02-01

    Abstract Background Skeletal muscle fibres represent one of the most abundant cell types in mammals. Their highly specialised contractile and metabolic functions depend on a large number of membrane-associated proteins with very high molecular masses, proteins with extensive posttranslational modifications and components that exist in highly complex supramolecular structures. This makes it extremely difficult to perform conventional biochemical studies of potential changes in protein clusters during physiological adaptations or pathological processes. Results Skeletal muscle proteomics attempts to establish the global identification and biochemical characterisation of all members of the muscle-associated protein complement. A considerable number of proteomic studies have employed large-scale separation techniques, such as high-resolution two-dimensional gel electrophoresis or liquid chromatography, and combined them with mass spectrometry as the method of choice for high-throughput protein identification. Muscle proteomics has been applied to the comprehensive biochemical profiling of developing, maturing and aging muscle, as well as the analysis of contractile tissues undergoing physiological adaptations seen in disuse atrophy, physical exercise and chronic muscle transformation. Biomedical investigations into proteome-wide alterations in skeletal muscle tissues were also used to establish novel biomarker signatures of neuromuscular disorders. Importantly, mass spectrometric studies have confirmed the enormous complexity of posttranslational modifications in skeletal muscle proteins. Conclusions This review critically examines the scientific impact of modern muscle proteomics and discusses its successful application for a better understanding of muscle biology, but also outlines its technical limitations and emerging techniques to establish new biomarker candidates.

  10. Experimental Verification of Current Shear Design Equations for HSRC Beams

    Directory of Open Access Journals (Sweden)

    Attaullah Shah

    2012-07-01

    Full Text Available Experimental research on the shear capacity of HSRC (High Strength Reinforced Concrete beams is relatively very limited as compared to the NSRC (Normal Strength Reinforced Concrete beams. Most of the Building Codes determine the shear strength of HSRC with the help of empirical equations based on experimental work of NSRC beams and hence these equations are generally regarded as un-conservative for HSRC beams particularly at low level of longitudinal reinforcement. In this paper, 42 beams have been tested in two sets, such that in 21 beams no transverse reinforcement has been used, whereas in the remaining 21 beams, minimum transverse reinforcement has been used as per ACI-318 (American Concrete Institute provisions. Two values of compressive strength 52 and 61 MPa, three values of longitudinal steel ratio and seven values of shear span to depth ratio have been have been used. The beams were tested under concentrated load at the mid span. The results are compared with the equations proposed by different international building codes like ACI, AASHTO LRFD, EC (Euro Code, Canadian Code and Japanese Code for shear strength of HSRC beams.From comparison, it has been observed that some codes are less conservative for shear design of HSRC beams and further research is required to rationalize these equations.

  11. Characterization of irradiated fuel rods using pulsed eddy current techniques

    International Nuclear Information System (INIS)

    Martin, M.R.; Francis, W.C.

    1975-11-01

    A number of irradiated fuel rods and unfueled zircaloy cladding tubes (''water tubes'') were obtained from the Saxton reactor through arrangements with the Westinghouse Electric Corporation for use in subsequent irradiation effects and fuel behavior programs. A comprehensive nondestructive and corroborative destructive characterization program was undertaken on these fuel rods and tubes by ANC to provide baseline data on their characteristics prior to further testing and for comparison against post-post data. This report deals primarily with one portion of the NDT program performed remotely in the hot cells. The portion of interest in this paper is the pulsed eddy current inspection used in the nondestructive phase of the work. 6 references

  12. Review of Surgical Techniques of Experimental Renal Transplantation in Rats.

    Science.gov (United States)

    Shrestha, Badri; Haylor, John

    2017-08-01

    Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.

  13. Techniques for data compression in experimental nuclear physics problems

    International Nuclear Information System (INIS)

    Byalko, A.A.; Volkov, N.G.; Tsupko-Sitnikov, V.M.

    1984-01-01

    Techniques and ways for data compression during physical experiments are estimated. Data compression algorithms are divided into three groups: the first one includes the algorithms based on coding and which posses only average indexes by data files, the second group includes algorithms with data processing elements, the third one - algorithms for converted data storage. The greatest promise for the techniques connected with data conversion is concluded. The techniques possess high indexes for compression efficiency and for fast response, permit to store information close to the source one

  14. Current control of superconducting coils for fusion experimental facility

    International Nuclear Information System (INIS)

    Ise, T.; Etou, D.; Chikaraishi, H.; Takami, S.; Inoue, T.

    2003-01-01

    The LHD (Large Helical Device) has twelve superconducting coils and six dc power supplies, and following specifications are required for its control system; each coil current must be controlled independently, the steady state control error is less than 0.01% of the reference value, the current settling time for 0.1% of control error is less than 1 second, and the control system must be robust against turbulence caused by appearance and disappearance of the plasma, parameter errors and external electro-magnetic noises. In this paper, the design and test results of the coil current control system for the LHD are described. The good response and robustness are in the relation of trade off each other. H-infinity controller is one of schemes to guarantee robustness for stability. However, the independent responses of six coils were impossible by the H-infinity controller only. To resolve this problem, we applied a feed-forward control with the H-infinity control. Moreover, the advanced design method of H-infinity controller using μ-synthesis was applied to guarantee the control performance in the whole operating condition. As a result, good control results were obtained by experiments. (author)

  15. Experimental study of anti-tumor activity of direct current

    International Nuclear Information System (INIS)

    Ito, Hisao; Hashimoto, Shozo

    1989-01-01

    The anti-tumor activity of direct current combined with radiation was studied. The experiments were performed with fibrosarcomas (FSA, NFSA) syngenetic to C3H mice. Direct current (0.6mA, 120min) alone was effective to reduce the tumor sizes, but could not cure the tumors. When the direct current therapy (DC therapy) was combined with radiation the DC therapy following radiation was more effective than that before radiation. Using TCD 50 assay, the DC therapy enhanced the effect of a single dose of radiation with the dose-modifying factor of 1.2. However, tumor control rates by the combination therapy were more improved at the smaller doses of radiation than at the larger ones. When the single DC therapy (0.6mA, 120min) was applied immediately after the first radiation of fractionated one the combination therapy still showed the enhanced effect. However, both DC therapy and the radiation therapy were divided in three fractions, and the DC therapy (0.6mA, 40min) was applied after each radiation. Tumor growth retardation by the combination therapy was no different from that by radiation alone. This result suggests that there might be a minimum required dose of coulombs to show the effect of the combination therapy. (author)

  16. Measuring the corrosion rate of steel in concrete – effect of measurement technique, polarisation time and current

    DEFF Research Database (Denmark)

    Nygaard, Peter Vagn; Geiker, Mette Rica

    2012-01-01

    , are in some studies considered the main reasons for the variations. This paper presents an experimental study on the quantitative effect of polarisation time and current on the measured polarisation resistance – and thus the corrosion current density – of passively and actively corroding steel. Two...... electrochemical techniques often used in instruments for on-site corrosion rate measurements are investigated. On passively corroding reinforcement the measured polarisation resistance was for both techniques found to be highly affected by the polarisation time and current and no plateaus at either short or long...... rate for actively corroding steel. For both techniques guidelines for polarisation times and currents are given for (on-site) non-destructive corrosion rate measurements on reinforcement steel in concrete....

  17. Research technique and experimental device for thermal conductivity measurements of refractory compounds

    International Nuclear Information System (INIS)

    Vishnevetskaya, I.A.; Petrov, V.A.

    1977-01-01

    Proposed is a new axial technique for determining thermal conductivity coefficient of solids at temperatures above 1000 deg C with the use of internal heating of specimens by passing electric current and with experimental determining the thermal flows on the lateral side of the working section of the specimen. This method is usable for investigating the thermal conductivity of materials whose surface radiation characteristics are unknown or unstable and for carrying out experiments not only in vacuum, but also in various atmospheres. The overall fiducial error of the results of the method is evaluated at 4-5 % within the range of temperatures between 1200 and 2300 K. A description of the experimental installation is given

  18. Comparison of current tonometry techniques in measurement of intraocular pressure.

    Science.gov (United States)

    Kouchaki, Behrooz; Hashemi, Hassan; Yekta, Abbasali; Khabazkhoob, Mehdi

    2017-06-01

    To compare four tonometry techniques: Goldmann applanation tonometer (GAT), Dynamic contour tonometer (DCT), Non-contact tonometer (NCT), and Ocular Response Analyzer (ORA) in the measurement of intraocular pressure (IOP) and the impact of some corneal biomechanical factors on their performance. In this cross-sectional study, volunteers with normal ophthalmic examination and no history of eye surgery (except for uncomplicated cataract surgery) or trauma were selected. Twenty-five subjects were male, and 21 were female. The mean age was 48 ± 19.2 years. Anterior segment parameters were measured with Scheimpflug imaging. IOP was measured with GAT, DCT, NCT, and ORA in random order. A 95% limit of agreement of IOPs was analyzed. The impact of different parameters on the measured IOP with each device was evaluated by regression analysis. The average IOP measured with GAT, DCT, NCT, and ORA was 16.4 ± 3.5, 18.1 ± 3.4, 16.2 ± 3.9, and 17.3 ± 3.4 mmHg, respectively. The difference of IOP measured with NCT and GAT was not significant ( P  = 0.382). Intraocular pressure was significantly different between GAT with DCT and IOP CC ( P  tonometers.

  19. Experimental modeling of eddy currents and deflections for tokamak limiters

    International Nuclear Information System (INIS)

    Hua, T.Q.; Knott, M.J.; Turner, L.R.; Wehrle, R.B.

    1986-01-01

    In this study, experiments were performed to investigate deflection, current, and material stress in cantilever beams with the Fusion ELectromagnetic Induction eXperiment (FELIX) at the Argonne National Laboratory. Since structures near the plasma are typically cantilevered, the beams provide a good model for the limiter blades of a tokamak fusion reactor. The test pieces were copper, aluminum, phosphor bronze, and brass cantilever beams, clamped rigidly at one end with a nonconducting support frame inside the FELIX test volume. The primary data recorded as functions of time were the beam deflection measured with a noncontact electro-optical device, the total eddy current measured with a Rogowski coil and linking through a central hole in the beam, and the material stress extracted from strain gauges. Measurements of stress and deflection were taken at selected positions along the beam. The extent of the coupling effect depends on several factors. These include the size, the electrical and mechanical properties of the beam, segmenting of the beam, the decay rate of the dipole field, and the strength of the solenoid field

  20. Current cardiac imaging techniques for detection of left ventricular mass

    Directory of Open Access Journals (Sweden)

    Celebi Aksuyek S

    2010-06-01

    Full Text Available Abstract Estimation of left ventricular (LV mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR and cardiovascular computed tomography (CCT are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test.

  1. Endoluminal weight loss and metabolic therapies: current and future techniques.

    Science.gov (United States)

    Hill, Christine; Khashab, Mouen A; Kalloo, Anthony N; Kumbhari, Vivek

    2018-01-01

    Obesity is a public health epidemic associated with a number of comorbidities, most notably type 2 diabetes and hypertension, as well as elevated all-cause mortality. The treatment for obesity and its associated comorbidities has most recently expanded into the field of bariatric endoscopy. This field bridges a gap between lifestyle counseling with or without pharmaceutical treatment and the most effective treatment of obesity, bariatric surgery. Because of its minimally invasive nature, bariatric endoscopic therapy has the potential to appeal to the large sector of the obese population that resists surgery, as well as those early in the onset of obesity. To date, five endoscopic devices have been approved by the U.S. Food and Drug Administration for the treatment of obesity, and many more are in development, undergoing clinical trials, or being used around the world. Here, we present the current state of the field, highlight recent developments, and describe the clinical outcomes of these minimally invasive procedures in terms of weight loss, improvement in metabolic profile, and reduction in comorbidities. © 2017 New York Academy of Sciences.

  2. Petroleum Pumps’ Current and Vibration Signatures Analysis Using Wavelet Coherence Technique

    Directory of Open Access Journals (Sweden)

    Rmdan Shnibha

    2013-01-01

    Full Text Available Vibration analysis is widely used for rotating machinery diagnostics; however measuring vibration of operational oil well pumps is not possible. The pump’s driver’s current signatures may provide condition-related information without the need for an access to the pump itself. This paper investigates the degree of relationship between the pump’s driver’s current signatures and its induced vibration. This relationship between the driver’s current signatures (DCS and its vibration signatures (DVS is studied by calculating magnitude-squared coherence and phase coherence parameters at a certain frequency band using continuous wavelet transform (CWT. The CWT coherence-based technique allows better analysis of temporal evolution of the frequency content of dynamic signals and areas in the time-frequency plane where the two signals exhibit common power or consistent phase behaviour indicating a relationship between the signals. This novel approach is validated by experimental data acquired from 3 kW petroleum pump’s driver. Both vibration and current signatures were acquired under different speed and load conditions. The outcomes of this research suggest the use of DCS analysis as reliable and inexpensive condition monitoring tool, which could be implemented for oil pumps, real-time monitoring associated with condition-based maintenance (CBM program.

  3. Experimental comparison of manufacturing techniques of toughened and nanoreinforced polyamides

    Science.gov (United States)

    Siengchin, S.; Bergmann, C.; Dangtungee, R.

    2011-11-01

    Composites consisting of polyamide-6 (PA-6), nitrile rubber (NBR), and sodium fluorohectorite (FH) or alumina silicate (Sungloss; SG) were produced by different techniques with latex precompounding. Their tensile and thermomechanical properties were determined by using tensile tests and a dynamic-mechanical analysis, performed at various temperatures. The PA-6/NBR composite systems produced by the direct melt compounding outperformed those obtained by using the masterbatch technique with respect to the strength and ductility, but the latter ones had a higher storage modulus.

  4. Determination of dynamic fracture toughness using a new experimental technique

    Directory of Open Access Journals (Sweden)

    Cady Carl M.

    2015-01-01

    Full Text Available In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ∼0.15 mm/s to 2.5 m/s. Digital image correlation (DIC will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

  5. Determination of dynamic fracture toughness using a new experimental technique

    Science.gov (United States)

    Cady, Carl M.; Liu, Cheng; Lovato, Manuel L.

    2015-09-01

    In other studies dynamic fracture toughness has been measured using Charpy impact and modified Hopkinson Bar techniques. In this paper results will be shown for the measurement of fracture toughness using a new test geometry. The crack propagation velocities range from ˜0.15 mm/s to 2.5 m/s. Digital image correlation (DIC) will be the technique used to measure both the strain and the crack growth rates. The boundary of the crack is determined using the correlation coefficient generated during image analysis and with interframe timing the crack growth rate and crack opening can be determined. A comparison of static and dynamic loading experiments will be made for brittle polymeric materials. The analysis technique presented by Sammis et al. [1] is a semi-empirical solution, however, additional Linear Elastic Fracture Mechanics analysis of the strain fields generated as part of the DIC analysis allow for the more commonly used method resembling the crack tip opening displacement (CTOD) experiment. It should be noted that this technique was developed because limited amounts of material were available and crack growth rates were to fast for a standard CTOD method.

  6. Techniques of Differentiation and Integration, Mathematics (Experimental): 5297.27.

    Science.gov (United States)

    Forrester, Gary B.

    This guidebook on minimum course content was designed for students who have mastered the skills and concepts of analytic geometry. It is a short course in the basic techniques of calculus recommended for the student who has need of these skills in other courses such as beginning physics, economics or statistics. The course does not intend to teach…

  7. Current Experimental Studies of Gene Therapy in Parkinson's Disease

    Directory of Open Access Journals (Sweden)

    Jing-ya Lin

    2017-05-01

    Full Text Available Parkinson's disease (PD was characterized by late-onset, progressive dopamine neuron loss and movement disorders. The progresses of PD affected the neural function and integrity. To date, most researches had largely addressed the dopamine replacement therapies, but the appearance of L-dopa-induced dyskinesia hampered the use of the drug. And the mechanism of PD is so complicated that it's hard to solve the problem by just add drugs. Researchers began to focus on the genetic underpinnings of Parkinson's disease, searching for new method that may affect the neurodegeneration processes in it. In this paper, we reviewed current delivery methods used in gene therapies for PD, we also summarized the primary target of the gene therapy in the treatment of PD, such like neurotrophic factor (for regeneration, the synthesis of neurotransmitter (for prolong the duration of L-dopa, and the potential proteins that might be a target to modulate via gene therapy. Finally, we discussed RNA interference therapies used in Parkinson's disease, it might act as a new class of drug. We mainly focus on the efficiency and tooling features of different gene therapies in the treatment of PD.

  8. Quantitative Evaluation of Defect in Stainless Steel 304 Tube Using Pulsed Eddy Current Technique

    International Nuclear Information System (INIS)

    Nurul Ain Ahmad Latif; Ilham Mukriz Zainal Abidin; Nurul Ain Ahmad Latif; Nordin Jamaludin; Zaredah Hashim; Norhayati Ramli

    2016-01-01

    Pulsed eddy current (PEC) is an advanced non-destructive testing (NDT) technique that operates based on electromagnetic principle. The excitation consists of broad frequency spectrum leading to be a potential in detecting defects that are deeply buried inside the specimen. In this paper, the experiment and simulation were conducted on stainless steel plate 304 fabricated with open surface defects having a different defect depth as an investigation towards the correlation between extracted signal feature and defect depth. Two common features; time to peak and peak value that corresponds to the location depth of defect and size of defect were used for signals analysis and evaluation. The results that acquired through finite element method (FEM) simulation were compared with experimental results for the signals evaluation and defect quantification. (author)

  9. Experimental technique of stress analyses by neutron diffraction

    International Nuclear Information System (INIS)

    Sun, Guangai; Chen, Bo; Huang, Chaoqiang

    2009-09-01

    The structures and main components of neutron diffraction stress analyses spectrometer, SALSA, as well as functions and parameters of each components are presented. The technical characteristic and structure parameters of SALSA are described. Based on these aspects, the choice of gauge volume, method of positioning sample, determination of diffraction plane and measurement of zero stress do are discussed. Combined with the practical experiments, the basic experimental measurement and the related settings are introduced, including the adjustments of components, pattern scattering, data recording and checking etc. The above can be an instruction for stress analyses experiments by neutron diffraction and neutron stress spectrometer construction. (authors)

  10. Moessbauer effect in lattice dynamics. Experimental techniques and applications

    International Nuclear Information System (INIS)

    Chen, Yi-Long; Yang, De-Ping

    2007-01-01

    This up-to-date review closes an important gap in the existing literature by providing a comprehensive description of the applications of Moessbauer effect in lattice dynamics, along with a collection of applications in metals, alloys, amorphous solids, molecular crystals, thin films, and nanocrystals. It is the first book to systematically compare Moessbauer spectroscopy using synchrotron radiation to conventional Moessbauer spectroscopy, discussing in detail its advantages and capabilities, backed by the latest theoretical developments and experimental examples. Intended as a self-contained volume that may be used as a complete reference or textbook, 'Moessbauer Effect in Lattice Dynamics' adopts new pedagogical approaches with several non-traditional and refreshing theoretical expositions, while all quantitative relations are derived with the necessary details so as to be easily followed by the reader. Two entire chapters are devoted to the study of the dynamics of impurity atoms in solids, while a thorough description of the Mannheim model as a theoretical method is presented and its predictions compared to experimental results. Finally, an in-depth analysis of absorption of Moessbauer radiation is presented, based on recent research by one of the authors, resulting in an exact expression of fractional absorption and a method to determine the optimal thickness of an absorber. Supplemented by elaborate appendices containing constants and parameters. (orig.)

  11. Influence of crack length on crack depth measurement by an alternating current potential drop technique

    International Nuclear Information System (INIS)

    Raja, Manoj K; Mahadevan, S; Rao, B P C; Behera, S P; Jayakumar, T; Raj, Baldev

    2010-01-01

    An alternating current potential drop (ACPD) technique is used for sizing depth of surface cracks in metallic components. Crack depth estimations are prone to large deviations when ACPD measurements are made on very shallow and finite length cracks, especially in low conducting materials such as austenitic stainless steel (SS). Detailed studies have been carried out to investigate the influence of crack length and aspect ratio (length to depth) on depth estimation by performing measurements on electric discharge machined notches with the aspect ratio in the range of 1 to 40 in SS plates. In notches with finite length, an additional path for current to flow through the surface along the length is available causing the notch depths to be underestimated. The experimentally observed deviation in notch depth estimates is explained from a simple mathematical approach using the equivalent resistive circuit model based on the additional path available for the current to flow. A scheme is proposed to accurately measure the depth of cracks with finite lengths in SS components

  12. Current status of antiproton impact ionization of atoms and molecules: theoretical and experimental perspectives

    DEFF Research Database (Denmark)

    Kirchner, Tom; Knudsen, Helge

    2011-01-01

    Experimental and theoretical progress in the field of antiproton-impact-induced ionization of atoms and molecules is reviewed. We describe the techniques used to measure ionization cross sections and give an overview of the experimental results supplemented by tables of all existing data. An atte......Experimental and theoretical progress in the field of antiproton-impact-induced ionization of atoms and molecules is reviewed. We describe the techniques used to measure ionization cross sections and give an overview of the experimental results supplemented by tables of all existing data...

  13. Experimental and Computational Techniques in Soft Condensed Matter Physics

    Science.gov (United States)

    Olafsen, Jeffrey

    2010-09-01

    1. Microscopy of soft materials Eric R. Weeks; 2. Computational methods to study jammed Systems Carl F. Schrek and Corey S. O'Hern; 3. Soft random solids: particulate gels, compressed emulsions and hybrid materials Anthony D. Dinsmore; 4. Langmuir monolayers Michael Dennin; 5. Computer modeling of granular rheology Leonardo E. Silbert; 6. Rheological and microrheological measurements of soft condensed matter John R. de Bruyn and Felix K. Oppong; 7. Particle-based measurement techniques for soft matter Nicholas T. Ouellette; 8. Cellular automata models of granular flow G. William Baxter; 9. Photoelastic materials Brian Utter; 10. Image acquisition and analysis in soft condensed matter Jeffrey S. Olafsen; 11. Structure and patterns in bacterial colonies Nicholas C. Darnton.

  14. Advanced Computational and Experimental Techniques for Nacelle Liner Performance Evaluation

    Science.gov (United States)

    Gerhold, Carl H.; Jones, Michael G.; Brown, Martha C.; Nark, Douglas

    2009-01-01

    The Curved Duct Test Rig (CDTR) has been developed to investigate sound propagation through a duct of size comparable to the aft bypass duct of typical aircraft engines. The axial dimension of the bypass duct is often curved and this geometric characteristic is captured in the CDTR. The semiannular bypass duct is simulated by a rectangular test section in which the height corresponds to the circumferential dimension and the width corresponds to the radial dimension. The liner samples are perforate over honeycomb core and are installed on the side walls of the test section. The top and bottom surfaces of the test section are acoustically rigid to simulate a hard wall bifurcation or pylon. A unique feature of the CDTR is the control system that generates sound incident on the liner test section in specific modes. Uniform air flow, at ambient temperature and flow speed Mach 0.275, is introduced through the duct. Experiments to investigate configuration effects such as curvature along the flow path on the acoustic performance of a sample liner are performed in the CDTR and reported in this paper. Combinations of treated and acoustically rigid side walls are investigated. The scattering of modes of the incident wave, both by the curvature and by the asymmetry of wall treatment, is demonstrated in the experimental results. The effect that mode scattering has on total acoustic effectiveness of the liner treatment is also shown. Comparisons of measured liner attenuation with numerical results predicted by an analytic model based on the parabolic approximation to the convected Helmholtz equation are reported. The spectra of attenuation produced by the analytic model are similar to experimental results for both walls treated, straight and curved flow path, with plane wave and higher order modes incident. The numerical model is used to define the optimized resistance and reactance of a liner that significantly improves liner attenuation in the frequency range 1900-2400 Hz. A

  15. Experimental study of bubbly flow using image processing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Yucheng, E-mail: ycfu@vt.edu; Liu, Yang, E-mail: liu130@vt.edu

    2016-12-15

    This paper presents an experimental study of bubbly flows at relatively high void fractions using an advanced image processing method. Bubble overlapping is a common problem in such flows and the past studies often treat the overlapping bubbles as a whole, which introduces considerable measurement uncertainties. In this study, a hybrid method combining intersection point detection and watershed segmentation is used to separate the overlapping bubbles. In order to reconstruct bubbles from separated segments, a systematic procedure is developed which can preserve more features captured in the raw image compared to the simple ellipse fitting method. The distributions of void fraction, interfacial area concentration, number density and velocity are obtained from the extracted bubble information. High-speed images of air-water bubbly flows are acquired and processed for eight test runs conducted in a 30 mm × 10 mm rectangular channel. The developed image processing scheme can effectively separate overlapping bubbles and the results compare well with the measurements by the gas flow meter and double-sensor conductivity probe. The development of flows in transverse and mainstream directions are analyzed and compared with the prediction made by the one-dimensional interfacial area transport equation (IATE) and the bubble number density transport equation.

  16. Experimental observation of current generation by asymmetrical heating of ions in a tokamak plasma

    International Nuclear Information System (INIS)

    Gahl, J.; Ishihara, O.; Wong, K.L.; Kristiansen, M.; Hagler, M.

    1986-01-01

    The first experimental observation of current generation by asymmetrical heating of ions is reported. Ions were asymmetrically heated by a unidirectional fast Alfven wave launched by a slow wave antenna inside a tokamak. Current generation was detected by measuring the asymmetry of the toroidal plasma current with probes at the top and bottom of the toroidal plasma column

  17. Currents, HF Radio-derived, SF Bay Outlet, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  18. Currents, HF Radio-derived, SF Bay, 1 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  19. Currents, HF Radio-derived, SF Bay, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  20. Currents, HF Radio-derived, Bodega Bay, 1 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 1 hour average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN EXPERIMENTAL...

  1. Physically-Based Interactive Flow Visualization Based on Schlieren and Interferometry Experimental Techniques

    KAUST Repository

    Brownlee, C.; Pegoraro, V.; Shankar, S.; McCormick, Patrick S.; Hansen, C. D.

    2011-01-01

    Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics (CFD) produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph, interferometry

  2. An overview of experimental techniques developed during hydrogeological investigations at Reskajeage Quarry, Cornwall

    International Nuclear Information System (INIS)

    Bolt, J.E.; Pascoe, D.M.; Watkins, V.M.B.

    1991-09-01

    In fractured rocks, the transport of dissolved radionuclides which may be released from the near-field of a radioactive waste repository will take place dominantly through the three dimensional network of fractures. Assessments of groundwater flow and radionuclide transport from an underground repository use continuum models, such as NAMMU, to predict radionuclide transport. To complement this approach, water flow and transport in fractured rock is being investigated at a more detailed level, using fracture network modelling. A test site, at Reskajeage Quarry in Cornwall, is currently being used to provide experimental data on flow and transport in fractured rock, to improve confidence in this modelling approach. This report describes the range of experimental techniques that have been used to obtain data on the positions, orientations and hydraulic properties of individual fractures in the slate. Also, brief descriptions of the design of a series of transport tests are given. The results of this work are described in a series of Nirex Safety Series Reports. (Author)

  3. An overview of experimental techniques developed during hydrogeological investigations at Reskajeage Quarry, Cornwall

    International Nuclear Information System (INIS)

    Bolt, J.E.; Pascoe, D.M.; Watkins, V.M.B.

    1991-09-01

    In fractured rocks, the transport of dissolved radionuclides which may be released from the near-field of a radioactive waste repository will take place dominantly through the three-dimensional network of fractures. Assessments of groundwater flow and radionuclide transport from an underground repository use continuum models, such as NAMMU, to predict radionuclide transport. To complement this approach, water flow and transport in fractured rock is being investigated at a more detailed level, using fracture network modelling. A test side, at Reskajeage Quarry in Cornwall, is currently being used to provide experimental data on flow and transport in fractured rock, to improve confidence in this modelling approach. This report describes the range of experimental techniques that have been used to obtain data on the positions, orientations and hydraulic properties of individual fractures in the slate. Also, brief descriptions of the design of a series of transport tests are given. The results of this work are described in a series of Nirex Safety Series Reports. (author)

  4. Experimental techniques for the study of radiation damage in metals and alloys

    International Nuclear Information System (INIS)

    Novion, C.H. de.

    1983-06-01

    In this review, one presents the main experimental techniques used to study point defects and defect clusters introduced by irradiation in metals and alloys; emphasis will be put on some recent techniques. In particular, the studies allowing to analyse the very small agglomerates of point defects (Huang and small angle scattering, positron annihilation, electron microscopy) will be compared [fr

  5. Enhancing the capabilities of eddy current techniques for non-destructive evaluation of austenitic stainless steels

    International Nuclear Information System (INIS)

    Rao, B.P.C.; Thirunavukkarasu, S.; Sasi, B.; Jayakumar, T.; Baldev Raj

    2010-01-01

    Eddy current non-destructive evaluation (NDE) techniques find many applications during fabrication and in-service inspection of components made of stainless steel. In recent years, concurrent developments in electromagnetic field detection sensors such as giant magneto-resistive (GMR), giant-magneto impedance (GMI) and SQUIDs sensors, computers, microelectronics, and incorporating advanced signal and image processing techniques, have paved the way for enhancing the capabilities of existing eddy current (EC) techniques for examination of austenitic stainless steel (SS) plates, tubes and other geometries and several innovative methodologies have been developed. This paper highlights a few such applications in EC testing to austenitic stainless steel components used in fast reactors. (author)

  6. Effects of modulation techniques on the input current interharmonics of Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Zare, Firuz

    2018-01-01

    operation of the grid. This paper presents the effect of the symmetrical regularly sampled Space Vector Modulation (SVM) and Discontinuous Pulse Width Modulation-30olag (DPWM2) techniques, as the most popular modulation methods in the ASD applications, on the drive’s input current interharmonic magnitudes....... Further investigations are also devoted to the cases, where the Random Modulation (RM) technique is applied on the selected modulation strategies. The comparative results show that how different modulation techniques can influence the ASD’s input current interharmonics and consequently may...

  7. Non destructive technique for cracks detection by an eddy current in differential mode for steel frames

    International Nuclear Information System (INIS)

    Harzalla, S.; Chabaat, M.; Belgacem, F. Bin Muhammad

    2014-01-01

    In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing results for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented

  8. Non destructive technique for cracks detection by an eddy current in differential mode for steel frames

    Energy Technology Data Exchange (ETDEWEB)

    Harzalla, S., E-mail: harzallahozil@yahoo.fr; Chabaat, M., E-mail: mchabaat@yahoo.com [Built Environmental Research Laboratory, Civil Engineering Faculty, University of Sciences and Technology Houari Boumediene, B.P. 32 El Alia Bab-Ezzouar, Algiers 16111 (Algeria); Belgacem, F. Bin Muhammad, E-mail: fbmbelgacem@gmail.com [Department of Mathematics, Faculty of Basic Education, PAAET, Al-Aardhia (Kuwait)

    2014-12-10

    In this paper, a nondestructive technique is used as a tool to control cracks and microcracks in materials. A simulation by a numerical approach such as the finite element method is employed to detect cracks and eventually; to study their propagation using a crucial parameter such as the stress intensity factor. This approach has been used in the aircraft industry to control cracks. Besides, it makes it possible to highlight the defects of parts while preserving the integrity of the controlled products. On the other side, it is proven that the reliability of the control of defects gives convincing results for the improvement of the quality and the safety of the material. Eddy current testing (ECT) is a standard technique in industry for the detection of surface breaking flaws in magnetic materials such as steels. In this context, simulation tools can be used to improve the understanding of experimental signals, optimize the design of sensors or evaluate the performance of ECT procedures. CEA-LIST has developed for many years semi-analytical models embedded into the simulation platform CIVA dedicated to non-destructive testing. The developments presented herein address the case of flaws located inside a planar and magnetic medium. Simulation results are obtained through the application of the Volume Integral Method (VIM). When considering the ECT of a single flaw, a system of two differential equations is derived from Maxwell equations. The numerical resolution of the system is carried out using the classical Galerkin variant of the Method of Moments. Besides, a probe response is calculated by application of the Lorentz reciprocity theorem. Finally, the approach itself as well as comparisons between simulation results and measured data are presented.

  9. Experimental demonstration of synergy between electron cyclotron and lower hybrid current drive on Tore Supra

    International Nuclear Information System (INIS)

    Artaud, J.F.; Giruzzi, G.; Dumont, R.J.; Imbeaux, F.; Bibet, P.; Bouquey, F.; Clary, J.; Ekedahl, A.; Hoang, G.T.; Lennholm, M.; Magne, R.; Segui, J.L.

    2004-01-01

    Non-inductive current drive (CD) has two main applications in tokamaks: sustainment of a substantial fraction of the toroidal plasma current necessary for the plasma confinement and control of the plasma stability and transport properties by appropriate shaping of the current density profile. For the first kind of applications, lower hybrid (LH) waves are known to provide the highest efficiency (defined as the ratio of the driven current to the injected wave power), although with limited control capability. Conversely, electron cyclotron (EC) waves drive highly localized currents, and are therefore particularly suited for control purposes, but their CD efficiency is much lower than that of LH waves (typically, an order of magnitude in present day experiments). Various calculations have demonstrated an interesting property: the current driven by the simultaneous use of the two waves, I(LH+EC), can be significantly larger than the sum I(LH)+I(EC) of the currents separately driven by the two waves in the same plasma conditions. This property, called synergy effect. The peculiar experimental conditions attainable on the Tore Supra tokamak have allowed the first experimental demonstration of the synergy between EC and LH current drive. The significant improvement of the electron cyclotron current drive (ECCD) efficiency in the presence of low hybrid current drive (LHCD), predicted by kinetic theory and confirmed by stationary experiments on Tore Supra, opens up the possibility of using ECCD as an efficient current profile control tool in LHCD plasmas

  10. MUP, CEC-DES, STRADE. Codes for uncertainty propagation, experimental design and stratified random sampling techniques

    International Nuclear Information System (INIS)

    Amendola, A.; Astolfi, M.; Lisanti, B.

    1983-01-01

    The report describes the how-to-use of the codes: MUP (Monte Carlo Uncertainty Propagation) for uncertainty analysis by Monte Carlo simulation, including correlation analysis, extreme value identification and study of selected ranges of the variable space; CEC-DES (Central Composite Design) for building experimental matrices according to the requirements of Central Composite and Factorial Experimental Designs; and, STRADE (Stratified Random Design) for experimental designs based on the Latin Hypercube Sampling Techniques. Application fields, of the codes are probabilistic risk assessment, experimental design, sensitivity analysis and system identification problems

  11. Technique of Critical Current Density Measurement of Bulk Superconductor with Linear Extrapolation Method

    International Nuclear Information System (INIS)

    Adi, Wisnu Ari; Sukirman, Engkir; Winatapura, Didin S.

    2000-01-01

    Technique of critical current density measurement (Jc) of HTc bulk ceramic superconductor has been performed by using linear extrapolation with four-point probes method. The measurement of critical current density HTc bulk ceramic superconductor usually causes damage in contact resistance. In order to decrease this damage factor, we introduce extrapolation method. The extrapolating data show that the critical current density Jc for YBCO (123) and BSCCO (2212) at 77 K are 10,85(6) Amp.cm - 2 and 14,46(6) Amp.cm - 2, respectively. This technique is easier, simpler, and the use of the current flow is low, so it will not damage the contact resistance of the sample. We expect that the method can give a better solution for bulk superconductor application. Key words. : superconductor, critical temperature, and critical current density

  12. Critical current measurement in superconducting rings using an automatic inductive technique

    International Nuclear Information System (INIS)

    Gonzalez-Jorge, H.; Linares, B.; Quelle, I.; Carballo, E.; Romani, L.; Domarco, G.

    2007-01-01

    A measurement technique was developed to identify the critical current of superconducting rings. It is based on the detection of the voltage on a secondary coil when the current induced in the superconductor by a primary one go beyond to the critical value. The technique uses a DC power supply to control the AC current circulating by the primary circuit. Such circuit mainly consists on an AC power supply which gives a constant AC voltage, a primary inducting coil and a control coil with iron core. The AC current circulating by this circuit is modified with the change in the impedance of the control coil due to the fact of the DC current supplied by the power supply in parallel with it

  13. Comparison of experimental techniques for characterization of through-thickness texture variations

    DEFF Research Database (Denmark)

    Mishin, Oleg; Lauridsen, E.M.; Krieger Lassen, N.C.

    1999-01-01

    For the investigation of through-thickness texture gradients, a number of layers in rolled plates and sheets are inspected. Crystallographic textures in different layers can be characterized using several techniques. In the present work, traditional low-energy X-ray diffraction, the electron...... backscattering pattern technique in the scanning electron microscope and a novel technique which involves high energy synchrotron radiation are used for characterization of through-thickness texture variations in commercial purity cold-rolled aluminium. Important experimental aspects of these three techniques...

  14. Endovascular stentectomy using the snare over stent-retriever (SOS technique: An experimental feasibility study.

    Directory of Open Access Journals (Sweden)

    Tareq Meyer

    Full Text Available Feasibility of endovascular stentectomy using a snare over stent-retriever (SOS technique was evaluated in a silicon flow model and an in vivo swine model. In vitro, stentectomy of different intracranial stents using the SOS technique was feasible in 22 out of 24 (92% retrieval maneuvers. In vivo, stentectomy was successful in 10 out of 10 procedures (100%. In one case self-limiting vasospasm was observed angiographically as a technique related complication in the animal model. Endovascular stentectomy using the SOS technique is feasible in an experimental setting and may be transferred to a clinical scenario.

  15. Experimental investigation of powerful pulse current generators based on capacitive storage and explosive magnetic generators

    Science.gov (United States)

    Shurupov, A. V.; Zavalova, V. E.; Kozlov, A. V.; Shurupov, M. A.; Povareshkin, M. N.; Kozlov, A. A.; Shurupova, N. P.

    2018-01-01

    Experimental models of microsecond duration powerful generators of current pulses on the basis of explosive magnetic generators and voltage impulse generator have been developed for the electromagnetic pulse effects on energy facilities to verify their stability. Exacerbation of voltage pulse carried out through the use of electro explosive current interrupter made of copper wires with diameters of 80 and 120 μm. Experimental results of these models investigation are represented. Voltage fronts about 100 ns and the electric field strength of 800 kV/m are registered.

  16. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kaushal, Vikas; Margala, Martin [Department of Electrical and Computer Engineering, University of Massachusetts Lowell, MA, 01854 (United States); Yu Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman, E-mail: vikas_kaushal@student.uml.ed [Department of Electrical and Computer Engineering, University of Rochester, NY, 14627 (United States)

    2009-11-15

    In this paper, two different theoretical models, Comsol Multiphysics{sup TM} (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  17. Current transport modeling and experimental study of THz room temperature ballistic deflection transistors

    International Nuclear Information System (INIS)

    Kaushal, Vikas; Margala, Martin; Yu Qiaoyan; Ampadu, Paul; Guarino, Gregg; Sobolewski, Roman

    2009-01-01

    In this paper, two different theoretical models, Comsol Multiphysics TM (a Finite Element Analysis tool), and a field solver Atlas/Blaze from Silvaco, are compared qualitatively to study the effect of the deflector position, its size and electric field on the charge transport and its distribution along the channel, resulting in current outputs and leakages in ballistic deflection transistors (BDT). Silvaco simulations and experimental results were then used to study the lateral charge transport as a result of variation in electric field distribution, which controls the charge current along the channel in BDT. The electric field dependence of gain is also studied with experimental and theoretical results.

  18. Current trends in dextranomer hyaluronic acid copolymer (Deflux) injection technique for endoscopic treatment of vesicoureteral reflux.

    Science.gov (United States)

    Kirsch, Andrew J; Arlen, Angela M; Lackgren, Goran

    2014-08-01

    To determine the current preferred injection technique(s) for endoscopic management of pediatric vesicoureteral reflux (VUR). Since the approval of dextranomer hyaluronic acid copolymer (Dx/HA) in 2001, injection methods have evolved and now include the hydrodistention implantation technique (HIT) and double HIT as well as subureteral transurethral injection (STING) method. In July 2012, 278 pediatric urologists in the United States were contacted to complete a 15-question survey regarding Dx/HA injection technique(s) currently used in their practice. Fifty board-certified pediatric urologists completed the survey for a response rate of 18%. Most respondents (60%) were in a single-specialty group practice, and 12% were affiliated with an academic- or university-based practice. Respondents reported seeing a mean of 159 pediatric patients (range, 40-400 patients) with VUR annually, and 94% used Dx/HA ≥4 times in the past year. Forty-seven respondents (94%) reported using double HIT over the course of their career compared with 36 (72%) for STING and 30 (60%) for HIT (P injection techniques. A significantly higher percentage currently perform double HIT (92%) compared with either STING (24%) or HIT (34%; P <.001). Respondents reported the use of double HIT 15 times more often than STING technique and 5 times more often than HIT during the past 12 months (P <.001). The double HIT method is currently the most commonly performed technique for endoscopic correction of VUR by pediatric urologists in the United States. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Oscillation experiments on Cesar and Marius - Experimental devices and measurement techniques

    International Nuclear Information System (INIS)

    Brunet, Max; Guerange, Jacques; Morier, Francis; Tonolli, Jacky

    1969-02-01

    An original method of measurement of effective cross sections of fissile materials has been developed by the CEA: a central fuel element of a critical experimental reactor is replaced by a sample containing the material to be studied. The replacement technique is based on oscillating the fuel load of the central channel. Signals are measured which are proportional to reactivity variation and to neutron density disturbance at the vicinity of the central channel, these variation and disturbance being produced by the sample oscillation. Measurements have been performed on experimental reactors (Minerve in Fontenay-aux-Roses, and Cesar and Marius in Cadarache). The authors herein describe the experimental devices and measurement techniques implemented in Marius and Cesar. In a first part, they describe the experimental devices which have been used during the three measurement campaigns (between 1965 and 1967). They report the study of measurement accuracies, and of some problems related to the use of the local detector [fr

  20. Development of Eddy Current Technique for Reactor In-Core Flux Thimble Wear

    International Nuclear Information System (INIS)

    Park, S. S.; Jang, Y. Y.; Yim, C. Y.; Park, K. H.

    1990-01-01

    Since in-core flux thimble tube wear the due to flow-induced vibration could degrade the integrity of nuclear reactor, the effective detection and interpretation of the wear is important. In order to establish an inspection technique for thimble tubes, an eddy current experiment was performed to determine the optimum test frequency, defect sensitivity and evaluation accuracy. Eddy current probes were designed and fabricated with a theory. Specimens with artificial defects were fabricated using electro discharge machining method. The results from inspection technique developed and on-site inspection showed good applicability

  1. Nondestructive evaluation of a cermet coating using ultrasonic and eddy current techniques

    International Nuclear Information System (INIS)

    Roge, B.; Fahr, A.; Giguere, J.S.R.; McRae, K.I.

    2002-01-01

    This paper describes a series of experiments conducted to characterize cermet coatings using conventional ultrasonic and eddy current techniques as well as an ultrasonic leaky surface wave method. The results demonstrate the ability of these techniques to detect the presence of artificial defects on the surface or beneath the surface of the coating. In addition, ultrasonic tests in particular ultrasonic leaky surface waves demonstrate the ability to detect the presence of manufacturing flaws. Ultrasonic time-of-flight and eddy current quadrature measurements also show sensitivity to variations in coating thickness

  2. Experimental observations of stray current effects on steel fibres embedded in mortar

    DEFF Research Database (Denmark)

    Solgaard, A.O.S.; Carsana, M.; Geiker, M.R.

    2013-01-01

    It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study) investigat......It is known that stray direct current can cause corrosive damage over time to bar reinforced concrete, but knowledge on the consequences to steel fibre reinforced concrete is limited. This paper presents analyses and corresponding results from an experimental program (parametric study......) investigating the conditions required for current to be picked up by embedded steel fibres or reinforcement (rebars). The experiments showed that there is a clear ‘length effect’ related to the susceptibility of stray current being picked up by embedded steel (fibres or rebars): the shorter the reinforcement...

  3. Study of pulse stretching in high current power supplies using multipulse techniques

    International Nuclear Information System (INIS)

    Trendler, R.C.

    1977-01-01

    Considerable interest exists at Fermilab to increase the pulse width of the Neutrino Focusing Horn to permit an increase in beam spill length from twenty (20) microseconds to one (1) millisecond. Two techniques to do this were examined: (1) a high current transformer, and (2) increased bank capacitance using the multi-power supply technique. The transformer is the most straightforward conceptually; it is, however, a complicated device requiring sizable changes to the existing horn power supply. This alternative is briefly reviewed. The second scheme involves pulsing a 20 kv 200 ka power supply to establish the required load current and then maintaining this current by the sequential pulsing of a number of low voltage high current power supplies. This alternative is discussed in detail with the results of tests performed on the Fermilab Focusing Horn System

  4. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    Energy Technology Data Exchange (ETDEWEB)

    Pua, Uei; Tan, Cher Heng [Tan Tock Seng Hospital, Department of Diagnostic Radiology, Singapore (Singapore); Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong [Tan Tock Seng Hospital, Department of Cardiology, Singapore (Singapore)

    2014-08-28

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  5. Revisiting renovascular imaging for renal sympathetic denervation: current techniques and applications

    International Nuclear Information System (INIS)

    Pua, Uei; Tan, Cher Heng; Ho, Hee Hwa; Tan, Julian Ko Beng; Ong, Paul Jau Leong

    2015-01-01

    Renal sympathetic denervation (RDN) is an emerging technique in the treatment of resistant hypertension, most commonly performed using an endovascular approach. Clinical and anatomical criteria for RDN are well established and imaging plays an integral role in selecting patients with suitable anatomy, procedural planning and device selection. Nevertheless, the current body of literature surrounding imaging related to RDN remains limited. The purpose of this article is to illustrate the expectations and limitations of various imaging techniques, including Doppler ultrasound, CT angiography, MR angiography and newer techniques such as non-contrast MR angiography, in the context of RDN. (orig.)

  6. Detection and Sizing of Fatigue Cracks in Steel Welds with Advanced Eddy Current Techniques

    Science.gov (United States)

    Todorov, E. I.; Mohr, W. C.; Lozev, M. G.

    2008-02-01

    Butt-welded specimens were fatigued to produce cracks in the weld heat-affected zone. Advanced eddy current (AEC) techniques were used to detect and size the cracks through a coating. AEC results were compared with magnetic particle and phased-array ultrasonic techniques. Validation through destructive crack measurements was also conducted. Factors such as geometry, surface treatment, and crack tightness interfered with depth sizing. AEC inspection techniques have the potential of providing more accurate and complete sizing flaw data for manufacturing and in-service inspections.

  7. Instrumentation, computer software and experimental techniques used in low-frequency internal friction studies at WNRE

    International Nuclear Information System (INIS)

    Sprugmann, K.W.; Ritchie, I.G.

    1980-04-01

    A detailed and comprehensive account of the equipment, computer programs and experimental methods developed at the Whiteshell Nuclear Research Estalbishment for the study of low-frequency internal friction is presented. Part 1 describes the mechanical apparatus, electronic instrumentation and computer software, while Part II describes in detail the laboratory techniques and various types of experiments performed together with data reduction and analysis. Experimental procedures for the study of internal friction as a function of temperature, strain amplitude or time are described. Computer control of these experiments using the free-decay technique is outlined. In addition, a pendulum constant-amplitude drive system is described. (auth)

  8. Inverse kinetics technique for reactor shutdown measurement: an experimental assessment. [AGR

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, T. A.; McDonald, D.

    1975-09-15

    It is proposed to use the Inverse Kinetics Technique to measure the subcritical reactivity as a function of time during the testing of the nitrogen injection systems on AGRs. A description is given of an experimental assessment of the technique by investigating known transients created by control rod movements on a small experimental reactor, (2m high, 1m radius). Spatial effects were observed close to the moving rods but otherwise derived reactivities were independent of detector position and agreed well with the existing calibrations. This prompted the suggestion that data from installed reactor instrumentation could be used to calibrate CAGR control rods.

  9. Calculation and experimental technique of determination of rolling procedure for cold-rolling tube mills

    International Nuclear Information System (INIS)

    Igoshin, V.F.; Aleshin, V.A.; Khoroshikh, Yu.G.; Bogatov, A.A.; Mizhiritskij, O.I.

    1983-01-01

    Calculation and experimental technique of determination of tube cold rolling procedure has been developed. Rolling procedure based on the usage of regression equation epsilon=1.24 psi, where psi is the relative reduction of area, delta-permissible reduction during rolling, has been tested on 08Kh18N10T steel. The effect of tube geometry, tool calibration parameters, lubrication conditions etc. on metal deformability in taking into account experimentally. The use of the technique proposed has allowed to shorten the time of mastering of the production of tubes from different steels

  10. Annular gap measurement between pressure tube and calandria tube by eddy current technique

    International Nuclear Information System (INIS)

    Bhole, V.M.; Rastogi, P.K.; Kulkarni, P.G.

    1992-01-01

    In pressurised heavy water reactor (PHWR) major distinguishing feature is that there are number of identical fuel channels in the reactor core. Each channel consists of pressure tube of Zr-2.5 Nb or zircaloy-2 through which high temperature, high pressure primary coolant is passing. The pressure tube contains fuel. Surrounding the pressure tube there is low pressure, cool heavy water (moderator). The moderator is thermally separated from coolant by the tube which is nominally concentric with pressure tube called calandria tube. There are four garter springs in the annular gap between pressure tube and calandria tube. During the life of the reactor there are number of factors by which the pressure tube sags, most important factors are irradiation creep, thermal creep, fuel load etc. Because of the sag of pressure tube it can touch the calandria tube resulting in formation of cold spot. This leads to hydrogen concentration at that spot by which the material at that place becomes brittle and can lead to catastrophic failure of pressure tube. There is no useful access for measurement of annular gap either through the gas annular space or from exterior of calandria tube. So the annular gap was measured from inside surface of pressure tube which is accessible. Eddy current technique was used for finding the gap. The paper describe the details of split coil design of bobbin probe, selection of operating point on normalised impedance diagram by choosing frequency. Experimental results on full scale mock up, and actual gap measurement in reactor channel, are also given. (author). 7 figs

  11. Experimental Study on the Molten Corium Interaction with Structure by Induction Heating Technique

    Energy Technology Data Exchange (ETDEWEB)

    An, Sang Mo; Ha, Kwang Soon; Min, Beong Tae; Hong, Seong Ho; Kim, Hwan Yeol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The corium compositions strongly depend on the accident scenarios, and thus the melt generation technique for various melt compositions is essential to investigate the corium-structural material interaction characteristics according to the accident scenarios. Since 1997, KAERI has several years of experiences with melt generation to investigate the material ablation characteristics and steam explosion phenomena. Based on the experiences of the TROI (Test for Real cOrium Interaction with water) facility for the steam explosion experiments, the VESTA (Verification of Ex-vessel corium STAbilization) test facility was designed and constructed in 2010 for the development of a core catcher under the APR+ project. At the same time, the VESTA-S (VESTA-Small) was established for small scale material ablation experiments. Some experimental results were reported for the interactions of metallic or oxidic melt with the structural materials such as special concrete or penetration weld. The objective of this paper is to provide the specific features of the VESTA and VESTA-S facilities including information on the melt generation technique adopted for the facilities. Some issues are also addressed in this paper for further facility improvement. In the present paper, the principles of induction heating adopted for the VESTA and VESTA-S facilities were summarized briefly and the system features for the melt-structural material interaction experiments were explained. As a major characteristic of the VESTA facility, up to 400 kg of corium melt is expected to be generated using the currently installed system. The jet impingement effect on the material ablation characteristics was demonstrated successfully in the VESTA facility. In the VESTA-S facility, the small scale material ablation experiments by long term melt interaction were performed properly by adopting the melt delivery method. However, for a more realistic severe accident simulation, we need to improve the melt temperature

  12. Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

    Directory of Open Access Journals (Sweden)

    Patcharoen Theerasak

    2018-04-01

    Full Text Available This paper describes the combination of discrete wavelet transforms (DWT and artificial intelligence (AI, which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51 and unbalanced current (60C protection relay for an application of shunt capacitor bank protection in the future.

  13. Simulation study and experimental results for detection and classification of the transient capacitor inrush current using discrete wavelet transform and artificial intelligence

    Science.gov (United States)

    Patcharoen, Theerasak; Yoomak, Suntiti; Ngaopitakkul, Atthapol; Pothisarn, Chaichan

    2018-04-01

    This paper describes the combination of discrete wavelet transforms (DWT) and artificial intelligence (AI), which are efficient techniques to identify the type of inrush current, analyze the origin and possible cause on the capacitor bank switching. The experiment setup used to verify the proposed techniques can be detected and classified the transient inrush current from normal capacitor rated current. The discrete wavelet transforms are used to detect and classify the inrush current. Then, output from wavelet is acted as input of fuzzy inference system for discriminating the type of switching transient inrush current. The proposed technique shows enhanced performance with a discrimination accuracy of 90.57%. Both simulation study and experimental results are quite satisfactory with providing the high accuracy and reliability which can be developed and implemented into a numerical overcurrent (50/51) and unbalanced current (60C) protection relay for an application of shunt capacitor bank protection in the future.

  14. Correlates of experimentation with smoking and current cigarette consumption among adolescents

    Directory of Open Access Journals (Sweden)

    Amanda Gimenes Bonilha

    2014-12-01

    Full Text Available OBJECTIVE: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. METHODS: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. RESULTS: A total of 2,014 students (mean age, 16.2 ± 1.1 years; females, 53% completed the questionnaire. We categorized 1,283 students (63.7% as never-smokers, 244 (12.1% as current smokers, and 487 (24.2% as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80, alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64, illicit drug use (OR = 9.32, having a sibling or cousin who smokes (OR = 1.39, having a friend who smokes (OR = 2.08, and high levels of stress (in females only, OR = 1.32. Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16, illicit drug use (OR = 3.61, and having a friend who smokes (OR = 7.20. CONCLUSIONS: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use suggest the need for comprehensive approaches to discourage substance use during adolescence.

  15. Correlates of experimentation with smoking and current cigarette consumption among adolescents* **

    Science.gov (United States)

    Bonilha, Amanda Gimenes; Ruffino-Netto, Antonio; Sicchieri, Mayara Piani; Achcar, Jorge Alberto; Rodrigues-Júnior, Antonio Luiz; Baddini-Martinez, José

    2014-01-01

    OBJECTIVE: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. METHODS: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. RESULTS: A total of 2,014 students (mean age, 16.2 ± 1.1 years; females, 53%) completed the questionnaire. We categorized 1,283 students (63.7%) as never-smokers, 244 (12.1%) as current smokers, and 487 (24.2%) as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80), alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64), illicit drug use (OR = 9.32), having a sibling or cousin who smokes (OR = 1.39), having a friend who smokes (OR = 2.08), and high levels of stress (in females only, OR = 1.32). Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16), illicit drug use (OR = 3.61), and having a friend who smokes (OR = 7.20). CONCLUSIONS: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use) suggest the need for comprehensive approaches to discourage substance use during adolescence. PMID:25610504

  16. Experimental and Numerical Investigation of Local Scour Around Submarine Piggyback Pipeline Under Steady Current

    Science.gov (United States)

    Zhao, Enjin; Shi, Bing; Qu, Ke; Dong, Wenbin; Zhang, Jing

    2018-04-01

    As a new type of submarine pipeline, the piggyback pipeline has been gradually adopted in engineering practice to enhance the performance and safety of submarine pipelines. However, limited simulation work and few experimental studies have been published on the scour around the piggyback pipeline under steady current. This study numerically and experimentally investigates the local scour of the piggyback pipe under steady current. The influence of prominent factors such as pipe diameter, inflow Reynolds number, and gap between the main and small pipes, on the maximum scour depth have been examined and discussed in detail. Furthermore, one formula to predict the maximum scour depth under the piggyback pipeline has been derived based on the theoretical analysis of scour equilibrium. The feasibility of the proposed formula has been effectively calibrated by both experimental data and numerical results. The findings drawn from this study are instructive in the future design and application of the piggyback pipeline.

  17. Current techniques in postmortem imaging with specific attention to paediatric applications

    International Nuclear Information System (INIS)

    Sieswerda-Hoogendoorn, Tessa; Rijn, Rick R. van

    2010-01-01

    In this review we discuss the decline of and current controversies regarding conventional autopsies and the use of postmortem radiology as an adjunct to and a possible alternative for the conventional autopsy. We will address the radiological techniques and applications for postmortem imaging in children. (orig.)

  18. Current techniques in postmortem imaging with specific attention to paediatric applications

    Energy Technology Data Exchange (ETDEWEB)

    Sieswerda-Hoogendoorn, Tessa; Rijn, Rick R. van [Academic Medical Centre Amsterdam, Department of Radiology, Amsterdam Zuid-Oost (Netherlands); Netherlands Forensic Institute, Department of Pathology and Toxicology, The Hague (Netherlands)

    2010-02-15

    In this review we discuss the decline of and current controversies regarding conventional autopsies and the use of postmortem radiology as an adjunct to and a possible alternative for the conventional autopsy. We will address the radiological techniques and applications for postmortem imaging in children. (orig.)

  19. The knee meniscus: structure-function, pathophysiology, current repair techniques, and prospects for regeneration

    Science.gov (United States)

    Makris, Eleftherios A.; Hadidi, Pasha; Athanasiou, Kyriacos A.

    2011-01-01

    Extensive scientific investigations in recent decades have established the anatomical, biomechanical, and functional importance that the meniscus holds within the knee joint. As a vital part of the joint, it acts to prevent the deterioration and degeneration of articular cartilage, and the onset and development of osteoarthritis. For this reason, research into meniscus repair has been the recipient of particular interest from the orthopedic and bioengineering communities. Current repair techniques are only effective in treating lesions located in the peripheral vascularized region of the meniscus. Healing lesions found in the inner avascular region, which functions under a highly demanding mechanical environment, is considered to be a significant challenge. An adequate treatment approach has yet to be established, though many attempts have been undertaken. The current primary method for treatment is partial meniscectomy, which commonly results in the progressive development of osteoarthritis. This drawback has shifted research interest towards the fields of biomaterials and bioengineering, where it is hoped that meniscal deterioration can be tackled with the help of tissue engineering. So far, different approaches and strategies have contributed to the in vitro generation of meniscus constructs, which are capable of restoring meniscal lesions to some extent, both functionally as well as anatomically. The selection of the appropriate cell source (autologous, allogeneic, or xenogeneic cells, or stem cells) is undoubtedly regarded as key to successful meniscal tissue engineering. Furthermore, a large variation of scaffolds for tissue engineering have been proposed and produced in experimental and clinical studies, although a few problems with these (e.g., byproducts of degradation, stress shielding) have shifted research interest towards new strategies (e.g., scaffoldless approaches, self-assembly). A large number of different chemical (e.g., TGF-β1, C-ABC) and

  20. An experimental technique to measure the capillary waves in electrified microjets

    Directory of Open Access Journals (Sweden)

    Rebollo-Muñoz Noelia

    2012-04-01

    Full Text Available Backlight optical imaging is an experimental technique with an enormous potential in microfluidics to study very varied fluid configurations and phenomena. In this paper, we show the capability of this technique to precisely characterize the capillary waves growing in electrified microjets. For this purpose, images of electrified liquid jets formed by electrospray were acquired and processed using a sub-pixel resolution technique. Our results reflect the validity and usefulness of optical imaging for this type of application.

  1. On the estimation of the current density in space plasmas: Multi- versus single-point techniques

    Science.gov (United States)

    Perri, Silvia; Valentini, Francesco; Sorriso-Valvo, Luca; Reda, Antonio; Malara, Francesco

    2017-06-01

    Thanks to multi-spacecraft mission, it has recently been possible to directly estimate the current density in space plasmas, by using magnetic field time series from four satellites flying in a quasi perfect tetrahedron configuration. The technique developed, commonly called ;curlometer; permits a good estimation of the current density when the magnetic field time series vary linearly in space. This approximation is generally valid for small spacecraft separation. The recent space missions Cluster and Magnetospheric Multiscale (MMS) have provided high resolution measurements with inter-spacecraft separation up to 100 km and 10 km, respectively. The former scale corresponds to the proton gyroradius/ion skin depth in ;typical; solar wind conditions, while the latter to sub-proton scale. However, some works have highlighted an underestimation of the current density via the curlometer technique with respect to the current computed directly from the velocity distribution functions, measured at sub-proton scales resolution with MMS. In this paper we explore the limit of the curlometer technique studying synthetic data sets associated to a cluster of four artificial satellites allowed to fly in a static turbulent field, spanning a wide range of relative separation. This study tries to address the relative importance of measuring plasma moments at very high resolution from a single spacecraft with respect to the multi-spacecraft missions in the current density evaluation.

  2. Means of Ensuring Information Security and Experimental Study of the Efficiency of Forensic Handwriting Techniques

    OpenAIRE

    Sergey Dmitrievich Kulik; Konstantin Igorevich Tkachenko; Denis Arturovich Nikonets

    2013-01-01

    This article deals with the special means, which allow to protect the information in the document. They are an integral part of the automated tools of ensuring the information security. It is proposed the use of a special input device PC Notes Taker. The results of experimental verification of the effectiveness of forensic handwriting techniques are described.

  3. Means of Ensuring Information Security and Experimental Study of the Efficiency of Forensic Handwriting Techniques

    Directory of Open Access Journals (Sweden)

    Sergey Dmitrievich Kulik

    2013-06-01

    Full Text Available This article deals with the special means, which allow to protect the information in the document. They are an integral part of the automated tools of ensuring the information security. It is proposed the use of a special input device PC Notes Taker. The results of experimental verification of the effectiveness of forensic handwriting techniques are described.

  4. Experimental evaluation of optimal Vehicle Dynamic Control based on the State Dependent Riccati Equation technique

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    Development and experimentally evaluation of an optimal Vehicle Dynamic Control (VDC) strategy based on the State Dependent Riccati Equation (SDRE) control technique is presented. The proposed nonlinear controller is based on a nonlinear vehicle model with nonlinear tire characteristics. A novel

  5. Experimental Study on Corrosion Detection of Aluminum Alloy Using Lamb Wave Mixing Technique

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Heeung; Lee, Jaesun; Cho, Younho [Pusan Nat’l Univ., Busan (Korea, Republic of)

    2016-11-15

    In this study, the Lamb wave mixing technique, which is basised on advanced research on the nonlinear bulk wave mixing technique, is applied for corrosion detection. To demonstrate the validity of the Lamb wave mixing technique, an experiment was performed with normal and corroded specimens. Comparison group in an experimentation are selected to mode and frequency with dominant in-plane displacement and out-of-plane displacement of Lamb waves. The results showed that the Lamb wave mixing technique can monitor corrosion defects, and it has a trend similar to that of the conventional Lamb wave technique. It was confirmed that the dominant displacement and mode matching the theory were generated. Flaw detectability is determined depending on displacement ratio instead of using the measurement method and mode selection.

  6. Development of an eddy current inspection technique for sleeved engine disk bolt holes

    International Nuclear Information System (INIS)

    Palanisamy, R.; Lakin, K.M.

    1983-01-01

    Recent research programs have concentrated mainly on developing techniques to characterize surface breaking cracks and very little has been done towards characterizing subsurface flaws in conducting materials. Presented in this paper are the results of some initial theoretical work aimed at the development of a reliable eddy current technique to detect and characterize defects in engine disk bolt holes under a 0.05'' stainless steel sleeve. The change in impedance of an absolute eddy current coil with and without ferrite core, and the distribution of eddy currents around a second layer crack with and without a thin insulating film between the two conducting layers have been predicted numerically. The overall system development goals and methods to accomplish them are outlined briefly

  7. Application of an eddy current technique to steam generator U-bend characterization. Final report

    International Nuclear Information System (INIS)

    Cramer, W.E.; de la Pintiere, L.; Narita, S.; Bergander, M.J.

    1982-04-01

    Eddy current nondestructive testing techniques are used widely throughout the utility industry for the early detection of tube damage in critical power plant components such as steam generators. In this project, the application of an eddy current technique for the characterization of U-bend transitions in the first row tubing in Westinghouse 51 Series Steam Generators has been investigated. A method has been developed for detection of the opposite transition in the U-bend and for defining its severity. Investigation included two different types of U-bend transitions. Using the developed eddy current method for U-bend characterization, on-site inspection was performed on all tubes in the first row in four 51 Series steam generators in Power Plant Unit No. 2 and in one 51 Series steam generator in Power Plant Unit No. 1. The advantages and limitations of the developed method as well as the recommendations for further investigations are included

  8. First experimental results with the Current Limit Avoidance System at the JET tokamak

    Energy Technology Data Exchange (ETDEWEB)

    De Tommasi, G. [Associazione EURATOM-ENEA-CREATE, Università di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Galeani, S. [Dipartimento di Informatica, Sistemi e Produzione, Università di Roma, Tor Vergata, Rome (Italy); Jachmich, S. [Association EURATOM-Belgian State, Koninklijke Militaire School - Ecole Royale Militaire, B-1000 Brussels (Belgium); Joffrin, E. [IRFM-CEA, Centre de Cadarache, 13108 Saint-paul-lez-Durance (France); Lennholm, M. [EFDA Close Support Unit, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); European Commission, B-1049 Brussels (Belgium); Lomas, P.J. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Neto, A.C. [Associazione EURATOM-IST, Instituto de Plasmas e Fusao Nuclear, IST, 1049-001 Lisboa (Portugal); Maviglia, F. [Associazione EURATOM-ENEA-CREATE, Via Claudio 21, 80125 Napoli (Italy); McCullen, P. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Pironti, A. [Associazione EURATOM-ENEA-CREATE, Università di Napoli Federico II, Via Claudio 21, 80125 Napoli (Italy); Rimini, F.G. [Euratom-CCFE, Culham Science Centre, OX14 3DB Abingdon (United Kingdom); Sips, A.C.C. [European Commission, B-1049 Brussels (Belgium); Varano, G.; Vitelli, R. [Dipartimento di Informatica, Sistemi e Produzione, Università di Roma, Tor Vergata, Rome (Italy); Zaccarian, L. [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31400 Toulouse (France); Universitè de Toulouse, LAAS, F-31400 Toulouse (France)

    2013-06-15

    The Current Limit Avoidance System (CLA) has been recently deployed at the JET tokamak to avoid current saturations in the poloidal field (PF) coils when the eXtreme Shape Controller is used to control the plasma shape. In order to cope with the current saturation limits, the CLA exploits the redundancy of the PF coils system to automatically obtain almost the same plasma shape using a different combination of currents in the PF coils. In the presence of disturbances it tries to avoid the current saturations by relaxing the constraints on the plasma shape control. The CLA system has been successfully implemented on the JET tokamak and fully commissioned in 2011. This paper presents the first experimental results achieved in 2011–2012 during the restart and the ITER-like wall campaigns at JET.

  9. Theoretical and experimental studies on ionic currents in nanopore-based biosensors.

    Science.gov (United States)

    Liu, Lei; Li, Chu; Ma, Jian; Wu, Yingdong; Ni, Zhonghua; Chen, Yunfei

    2014-12-01

    Novel generation of analytical technology based on nanopores has provided possibilities to fabricate nanofluidic devices for low-cost DNA sequencing or rapid biosensing. In this paper, a simplified model was suggested to describe DNA molecule's translocation through a nanopore, and the internal potential, ion concentration, ionic flowing speed and ionic current in nanopores with different sizes were theoretically calculated and discussed on the basis of Poisson-Boltzmann equation, Navier-Stokes equation and Nernst-Planck equation by considering several important parameters, such as the applied voltage, the thickness and the electric potential distributions in nanopores. In this way, the basic ionic currents, the modulated ionic currents and the current drops induced by translocation were obtained, and the size effects of the nanopores were carefully compared and discussed based on the calculated results and experimental data, which indicated that nanopores with a size of 10 nm or so are more advantageous to achieve high quality ionic current signals in DNA sensing.

  10. Weak interactions and exchange currents in light nuclei. Theoretical and experimental aspects

    International Nuclear Information System (INIS)

    Guichon, P.

    1980-01-01

    The influence of meson exchange currents in the nuclear weak interaction is investigated theoretically and experimentally. The hypothesis of current algebra and partial conservation of axial current are used, through Adler-Dothan theorem, to derive the one pion exchange correction to the impulse approximation. Calculations are performed for partial transitions in the 1p-shell nuclei and in 16 O. The corrections are generally small except for the (0 + →0 - ) transition in 16 O where the large correction to the time component of the axial current can show up, due to selection rules. The measurement of the muon capture rate for this transition is described and an interpretation in term of exchange currents is proposed [fr

  11. Current activities in development of PIE techniques in JMTR hot laboratory

    International Nuclear Information System (INIS)

    Ishii, Toshimitsu; Ohmi, Masao; Shimizu, Michio; Kaji, Yoshiyuki; Ueno, Fumiyoshi

    2006-01-01

    A wide variety of post-irradiation examinations (PIEs) for research and development of nuclear fuels and materials to be utilized in nuclear field has been carried out since 1971 in three kinds of β-γ hot cells; concrete, lead and steel cells in the JMTR Hot Laboratory (JMTR HL) associated with the Japan Materials Testing Reactor (JMTR). In addition to PIEs, the re-capsuling work including re-instrumentation was also conducted for the power ramping tests of the irradiated LWR fuels using Boiling Water Capsule (BOCA). Recently, new PIE techniques are required for the advanced irradiation studies. In this paper, the irradiation assisted stress corrosion cracking (IASCC) growth test technique of irradiated in-core structural materials and the remote operation technique of the atomic force microscope (AFM) are described as JMTR HL's current activities in the development of new PIE techniques. (author)

  12. Measurement of plasma current in Tokamaks using an optical fibre reflectometry technique

    Directory of Open Access Journals (Sweden)

    Wuilpart Marc

    2018-01-01

    Full Text Available An optical time-domain reflectometer sensitive to the polarization of light is proposed for the measurement of plasma current in the Tore Supra fusion reactor. The measurement principle relies on the Faraday effect i.e. on the generation of a circular birefringence along an optical fiber subject to an axial magnetic field. The circular birefringence induces a polarization rotation that can be mapped along the fiber thanks to an opticaltime domain reflectometer followed by an linear polarizer. A proper fitting of the measurement trace then allows determining the applied plasma current. The sensor has been experimentally validated on the Tore Supra tokamak fusion reactor for a plasma current range going from 0.6 to 1.5 MA. A maximum error of 13.50% has been observed for the lowest current.

  13. Experimental evaluation of a quasi-modal parameter based rotor foundation identification technique

    Science.gov (United States)

    Yu, Minli; Liu, Jike; Feng, Ningsheng; Hahn, Eric J.

    2017-12-01

    Correct modelling of the foundation of rotating machinery is an invaluable asset in model-based rotor dynamic study. One attractive approach for such purpose is to identify the relevant modal parameters of an equivalent foundation using the motion measurements of rotor and foundation at the bearing supports. Previous research showed that, a complex quasi-modal parameter based system identification technique could be feasible for this purpose; however, the technique was only validated by identifying simple structures under harmonic excitation. In this paper, such identification technique is further extended and evaluated by identifying the foundation of a numerical rotor-bearing-foundation system and an experimental rotor rig respectively. In the identification of rotor foundation with multiple bearing supports, all application points of excitation forces transmitted through bearings need to be included; however the assumed vibration modes far outside the rotor operating speed cannot or not necessary to be identified. The extended identification technique allows one to identify correctly an equivalent foundation with fewer modes than the assumed number of degrees of freedom, essentially by generalising the technique to be able to handle rectangular complex modal matrices. The extended technique is robust in numerical and experimental validation and is therefore likely to be applicable in the field.

  14. Maximum Bandwidth Enhancement of Current Mirror using Series-Resistor and Dynamic Body Bias Technique

    Directory of Open Access Journals (Sweden)

    V. Niranjan

    2014-09-01

    Full Text Available This paper introduces a new approach for enhancing the bandwidth of a low voltage CMOS current mirror. The proposed approach is based on utilizing body effect in a MOS transistor by connecting its gate and bulk terminals together for signal input. This results in boosting the effective transconductance of MOS transistor along with reduction of the threshold voltage. The proposed approach does not affect the DC gain of the current mirror. We demonstrate that the proposed approach features compatibility with widely used series-resistor technique for enhancing the current mirror bandwidth and both techniques have been employed simultaneously for maximum bandwidth enhancement. An important consequence of using both techniques simultaneously is the reduction of the series-resistor value for achieving the same bandwidth. This reduction in value is very attractive because a smaller resistor results in smaller chip area and less noise. PSpice simulation results using 180 nm CMOS technology from TSMC are included to prove the unique results. The proposed current mirror operates at 1Volt consuming only 102 µW and maximum bandwidth extension ratio of 1.85 has been obtained using the proposed approach. Simulation results are in good agreement with analytical predictions.

  15. Motor current and leakage flux signature analysis technique for condition monitoring

    International Nuclear Information System (INIS)

    Pillai, M.V.; Moorthy, R.I.K.; Mahajan, S.C.

    1994-01-01

    Till recently analysis of vibration signals was the only means available to predict the state of health of plant equipment. Motor current and leakage magnetic flux signature analysis is acquiring importance as a technique for detection of incipient damages in the electrical machines and as a supplementary technique for diagnostics of driven equipment such as centrifugal and reciprocating pumps. The state of health of the driven equipment is assessed by analysing time signal, frequency spectrum and trend analysis. For example, the pump vane frequency, piston stroke frequency, gear frequency and bearing frequencies are indicated in the current and flux spectra. By maintaining a periodic record of the amplitudes of various frequency lines in the frequency spectra, it is possible to understand the trend of deterioration of parts and components of the pump. All problems arising out of inappropriate mechanical alignment of vertical pumps are easily identified by a combined analysis of current, flux and vibration signals. It is found that current signature analysis technique is a sufficient method in itself for the analysis of state of health of reciprocating pumps and compressors. (author). 10 refs., 4 figs

  16. Experimental and theoretical contributions to X-ray phase-contrast techniques for medical imaging

    International Nuclear Information System (INIS)

    Diemoz, P.C.

    2011-01-01

    Several X-ray phase-contrast techniques have recently been developed. Unlike conventional X-ray methods, which measure the absorption properties of the tissues, these techniques derive contrast also from the modulation of the phase produced by the sample. Since the phase shift can be significant even for small details characterized by weak or absent absorption, the achievable image contrast can be greatly increased, notably for the soft biological tissues. These methods are therefore very promising for applications in the medical domain. The aim of this work is to contribute to a deeper understanding of these techniques, in particular propagation-based imaging (PBI), analyzer-based imaging (ABI) and grating interferometry (GIFM), and to study their potential and the best practical implementation for medical imaging applications. An important part of this work is dedicated to the use of mathematical algorithms for the extraction, from the acquired images, of quantitative sample information (the absorption, refraction and scattering sample properties). In particular, five among the most known algorithms based on the geometrical optics approximation have been theoretically analysed and experimentally compared, in planar and tomographic modalities, by using geometrical phantoms and human bone-cartilage and breast samples. A semi-quantitative method for the acquisition and reconstruction of tomographic images in the ABI and GIFM techniques has also been proposed. The validity conditions are analyzed in detail and the method, enabling a considerable simplification of the imaging procedure, has been experimentally checked on phantoms and human samples. Finally, a theoretical and experimental comparison of the PBI, ABI and GIFM techniques is presented. The advantages and drawbacks of each of these techniques are discussed. The results obtained from this analysis can be very useful for determining the most adapted technique for a given application. (author)

  17. Current status on techniques for determining paleo-temperature using geothermometer

    International Nuclear Information System (INIS)

    Kanazawa, Sunao; Oikawa, Teruki; Umeda, Koji; Tomiyama, Shingo

    2005-01-01

    Development of the research technologies for geotectonic events has been carried out to evaluate the long-term stability of geological environment. In terms of the effects of geothermal activity, it is necessary to estimate the geothermal regime and thermal history on any given site. This paper describes the current status on techniques for determining paleo-temperature using geothermometer, and presents a concept of the systematic research techniques. The application of geothermometer, especially thermochronology, has been effective in the studies on the cooling history of geological body and the paleo-geothermal structure at depth. (author)

  18. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow

    International Nuclear Information System (INIS)

    Gabriel, Stephan Gerhard

    2015-01-01

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  19. Experimental Investigation of a Direct Methanol Fuel Cell with Hilbert Fractal Current Collectors

    Directory of Open Access Journals (Sweden)

    Jing-Yi Chang

    2014-01-01

    Full Text Available The Hilbert curve is a continuous type of fractal space-filling curve. This fractal curve visits every point in a square grid with a size of 2×2, 4×4, or any other power of two. This paper presents Hilbert fractal curve application to direct methanol fuel cell (DMFC current collectors. The current collectors are carved following first, second, and third order Hilbert fractal curves. These curves give the current collectors different free open ratios and opening perimeters. We conducted an experimental investigation into DMFC performance as a function of the free open ratio and opening perimeter on the bipolar plates. Nyquist plots of the bipolar plates are made and compared using electrochemical impedance spectroscopy (EIS experiments to understand the phenomena in depth. The results obtained in this paper could be a good reference for future current collector design.

  20. Experimentally determined profiles of fast wave current drive on DIII-D

    International Nuclear Information System (INIS)

    Forest, C.B.; Petty, C.C.; Baity, F.W.; Chiu, S.C.; deGrassie, J.S.; Groebner, R.J.; Ikezi, H.; Jaeger, E.F.; Kupfer, K.; Murakami, M.; Pinsker, R.I.; Prater, R.; Rice, B.W.; Wade, M.R.; Whyte, D.G.

    1996-01-01

    Profiles of non-inductive current driven by fast waves have been determined for reversed-shear DIII-D discharges. Both the current profile and toroidal electric field profile are determined from time sequences of equilibrium reconstructions [C. B. Forest et al., Phys. Rev. Lett. 73, 2224 (1994)]. Using this information, the measured current profile has been separated into inductive and non-inductive portions. By comparing similar discharges with co and counter antenna phasings and similar fast wave power, the portion of the total non-inductive current driven by fast waves was determined. The experimentally determined profiles of FWCD are in general agreement with theoretical predictions. Specifically, 135 kA was driven by 1.4 MW of rf power with a profile peaked inside ρ=2. copyright 1996 American Institute of Physics

  1. Experimental verifications of a structural damage identification technique using reduced order finite-element model

    Science.gov (United States)

    Li, Rui; Zhou, Li; Yang, Jann N.

    2010-04-01

    An objective of the structural health monitoring system is to identify the state of the structure and to detect the damage when it occurs. Analysis techniques for the damage identification of structures, based on vibration data measured from sensors, have received considerable attention. Recently, a new damage tracking technique, referred to as the adaptive quadratic sum-square error (AQSSE) technique, has been proposed, and simulation studies demonstrated that the AQSSE technique is quite effective in identifying structural damages. In this paper, the adaptive quadratic sumsquare error (AQSSE) along with the reduced-order finite-element method is proposed to identify the damages of complex structures. Experimental tests were conducted to verify the capability of the proposed damage detection approach. A series of experimental tests were performed using a scaled cantilever beam subject to the white noise and sinusoidal excitations. The capability of the proposed reduced-order finite-element based adaptive quadratic sum-square error (AQSSE) method in detecting the structural damage is demonstrated by the experimental results.

  2. Analysis and Minimization of Output Current Ripple for Discontinuous Pulse-Width Modulation Techniques in Three-Phase Inverters

    Directory of Open Access Journals (Sweden)

    Gabriele Grandi

    2016-05-01

    Full Text Available This paper gives the complete analysis of the output current ripple in three-phase voltage source inverters considering the different discontinuous pulse-width modulation (DPWM strategies. In particular, peak-to-peak current ripple amplitude is analytically evaluated over the fundamental period and compared among the most used DPWMs, including positive and negative clamped (DPWM+ and DPWM−, and the four possible combinations between them, usually named as DPWM0, DPWM1, DPWM2, and DPWM3. The maximum and the average values of peak-to-peak current ripple are estimated, and a simple method to correlate the ripple envelope with the ripple rms is proposed and verified. Furthermore, all the results obtained by DPWMs are compared to the centered pulse-width modulation (CPWM, equivalent to the space vector modulation to identify the optimal pulse-width modulation (PWM strategy as a function of the modulation index, taking into account the different average switching frequency. In this way, the PWM technique providing for the minimum output current ripple is identified over the whole modulation range. The analytical developments and the main results are experimentally verified by current ripple measurements with a three-phase PWM inverter prototype supplying an induction motor load.

  3. Field- and current-driven domain wall dynamics: An experimental picture

    International Nuclear Information System (INIS)

    Beach, G.S.D.; Knutson, C.; Tsoi, M.; Erskine, J.L.

    2007-01-01

    Field- and current-driven domain wall velocities are measured and discussed in terms of existing spin-torque models. A reversal in the roles of adiabatic and non-adiabatic spin-torque is shown to arise in those models below and above Walker breakdown. The measured dependence of velocity on current is the same in both regimes, indicating both spin-torque components have similar magnitude. However, the models on which these conclusions are based have serious quantitative shortcomings in describing the observed field-driven wall dynamics, for which they were originally developed. Hence, the applicability of simple one-dimensional models to most experimental conditions may be limited

  4. Current Parental Depression and Offspring Perceived Self-Competence: A Quasi-Experimental Examination

    OpenAIRE

    Class, Quetzal A.; D’Onofrio, Brian M.; Singh, Amber L.; Ganiban, Jody M.; Spotts, E. L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

    2012-01-01

    A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52%) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-c...

  5. An Eddy Current Testing Platform System for Pipe Defect Inspection Based on an Optimized Eddy Current Technique Probe Design

    Science.gov (United States)

    Rifai, Damhuji; Abdalla, Ahmed N.; Razali, Ramdan; Ali, Kharudin; Faraj, Moneer A.

    2017-01-01

    The use of the eddy current technique (ECT) for the non-destructive testing of conducting materials has become increasingly important in the past few years. The use of the non-destructive ECT plays a key role in the ensuring the safety and integrity of the large industrial structures such as oil and gas pipelines. This paper introduce a novel ECT probe design integrated with the distributed ECT inspection system (DSECT) use for crack inspection on inner ferromagnetic pipes. The system consists of an array of giant magneto-resistive (GMR) sensors, a pneumatic system, a rotating magnetic field excitation source and a host PC acting as the data analysis center. Probe design parameters, namely probe diameter, an excitation coil and the number of GMR sensors in the array sensor is optimized using numerical optimization based on the desirability approach. The main benefits of DSECT can be seen in terms of its modularity and flexibility for the use of different types of magnetic transducers/sensors, and signals of a different nature with either digital or analog outputs, making it suited for the ECT probe design using an array of GMR magnetic sensors. A real-time application of the DSECT distributed system for ECT inspection can be exploited for the inspection of 70 mm carbon steel pipe. In order to predict the axial and circumference defect detection, a mathematical model is developed based on the technique known as response surface methodology (RSM). The inspection results of a carbon steel pipe sample with artificial defects indicate that the system design is highly efficient. PMID:28335399

  6. Application of Modern Experimental Technique to Solve Morphological Complexity in Plants Taxonomy

    Directory of Open Access Journals (Sweden)

    SURANTO

    2000-07-01

    Full Text Available Modern taxonomy has two approaches, i.e. classical and experimental taxonomy. Classical taxonomy uses morphological characters, while experimental taxonomy uses broader methods including chemistry, physics and mathematics, in the form of laboratory data that are revealed together with the progress of optical technique (microscope, chemistry methods (chromatography, electrophoresis, etc. Modern taxonomy tends to use series of interrelated data. More data used would result in more validity and give better clarification of taxonomic status. A lot of modern taxonomic data such as palynology, cytotaxonomy (cytology, chemical constituent (chemotaxonomy, isozyme and DNA sequencing were used recently.

  7. FORTRAN programs for transient eddy current calculations using a perturbation-polynomial expansion technique

    International Nuclear Information System (INIS)

    Carpenter, K.H.

    1976-11-01

    A description is given of FORTRAN programs for transient eddy current calculations in thin, non-magnetic conductors using a perturbation-polynomial expansion technique. Basic equations are presented as well as flow charts for the programs implementing them. The implementation is in two steps--a batch program to produce an intermediate data file and interactive programs to produce graphical output. FORTRAN source listings are included for all program elements, and sample inputs and outputs are given for the major programs

  8. Current techniques for visualizing RNA in cells [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lilith V.J.C. Mannack

    2016-04-01

    Full Text Available Labeling RNA is of utmost interest, particularly in living cells, and thus RNA imaging is an emerging field. There are numerous methods relying on different concepts ranging from hybridization-based probes, over RNA-binding proteins to chemo-enzymatic modification of RNA. These methods have different benefits and limitations. This review aims to outline the current state-of-the-art techniques and point out their benefits and limitations.

  9. Advantages and Limitations of Current Imaging Techniques for Characterizing Liposome Morphology

    Directory of Open Access Journals (Sweden)

    Annie-Louise Robson

    2018-02-01

    Full Text Available There are currently a number of imaging techniques available for evaluating the morphology of liposomes and other nanoparticles, with each having its own advantages and disadvantages that should be considered when interpreting data. Controlling and validating the morphology of nanoparticles is of key importance for the effective clinical translation of liposomal formulations. There are a number of physical characteristics of liposomes that determine their in vivo behavior, including size, surface characteristics, lamellarity, and homogeneity. Despite the great importance of the morphology of nanoparticles, it is generally not well-characterized and is difficult to control. Appropriate imaging techniques provide important details regarding the morphological characteristics of nanoparticles, and should be used in conjunction with other methods to assess physicochemical parameters. In this review, we will discuss the advantages and limitations of available imaging techniques used to evaluate liposomal formulations.

  10. Current status on detail design and fabrication techniques development of ITER blanket shield block in Korea

    International Nuclear Information System (INIS)

    Kim, Duck Hoi; Cho, Seungyon; Ahn, Mu-Young; Lee, Eun-Seok; Jung, Ki Jung

    2007-01-01

    The allocation of components and systems to be delivered to ITER on an in-kind basis, was agreed between the ITER Parties. Among parties, Korea agreed to procure inboard blanket modules 1, 2 and 6, which consists of FW and shield block. Regarding shield block the detail design and Fabrication techniques development have been undertaken in Korea. Especially manufacturing feasibility study on shield block had been performed and some technical issues for the fabrication were selected. Based on these results, fabrication techniques using EB welding are being developed. Meanwhile, the detail design of inboard standard module has been carried out. The optimization of flow driver design to improve the cooling performance was executed. And, thermo-hydraulic analysis on half block of inboard standard module was performed. In this study, current status and some results from Fabrication techniques development on ITER blanket shield block are described. The detail design activity and results on shield block are also introduced herein. (orig.)

  11. A Novel Sliding Mode Control Technique for Indirect Current Controlled Active Power Filter

    Directory of Open Access Journals (Sweden)

    Juntao Fei

    2012-01-01

    Full Text Available A novel sliding mode control (SMC method for indirect current controlled three-phase parallel active power filter is presented in this paper. There are two designed closed loops in the system: one is the DC voltage controlling loop and the other is the reference current tracking loop. The first loop with a PI regulator is used to control the DC voltage approximating to the given voltage of capacitor, and the output of PI regulator through a low-pass filter is applied as the input of the power supply reference currents. The second loop implements the tracking of the reference currents using integral sliding mode controller, which can improve the harmonic treating performance. Compared with the direct current control technique, it is convenient to be implemented with digital signal processing system because of simpler system structure and better harmonic treating property. Simulation results verify that the generated reference currents have the same amplitude with the load currents, demonstrating the superior harmonic compensating effects with the proposed shunt active power filter compared with the hysteresis method.

  12. Eddy current technique for detecting and sizing surface cracks in steel components

    International Nuclear Information System (INIS)

    Cecco, V.S.; Carter, J.R.; Sullivan, S.P.

    1995-01-01

    Cracking has occurred in pressure vessel nozzles and girth welds due to thermal fatigue. Pipe welds, welds in support structures, and welds in reactor vault liner panels in nuclear facilities have failed because of cracks. Cracking can also occur in turbine rotor bore surfaces due to high cycle fatigue. Dye penetrant, magnetic particle and other surface NDT methods are used to detect cracks but cannot be used for depth sizing. Crack depth can be measured with various NDT methods such as ultrasonic time-of-flight diffraction (TOFD), potential drop, and eddy current. The TOFD technique can be difficult to implement on nozzle welds and is best suited for sizing deep cracks (>5 mm). The conventional eddy current method is easy to implement, but crack sizing is normally limited to shallow cracks ( 2 mm) cracks. Eddy current testing (ET) techniques are readily amenable to remote/automatic inspections. These new probes could augment present magnetic particle (MT) and dye penetrant (PT) testing through provision of reliable defect depth information. Reliable crack sizing permits identification of critical cracks for plant life extension and licensing purposes. In addition, performing PT and MT generates low level radioactive waste in some inspection applications in nuclear facilities. Replacing these techniques with ET for some components will eliminate some of this radioactive waste. (author)

  13. Experimental Verification of Interference Mitigation Techniques for 5G Small Cells

    DEFF Research Database (Denmark)

    Assefa, Dereje; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão

    2015-01-01

    deployment with four cells, where each cell features one Access Point (AP) and one User Equipment (UE). In particular, we compare traditional Frequency Reuse Planning (FRP) with the recently proposed Maximum Rank Planning (MRP) technique, which relies on the degrees of freedom offered by the multi...... with the USRP N200 hardware by Ettus Research. The experimental results in a fully loaded network reveal the capability of the MRP technique to achieve higher throughput performance than FRP for 90% of the cases when IRC receivers are used. Lower network loads lead to further performance improvements for MRP....

  14. Experimental Study on Indoor Air Cleaning Technique of Nano-Titania Catalysis Under Plasma Discharge

    International Nuclear Information System (INIS)

    Gao Deli; Yang Xuechang; Zhou Fei; Wu Yuhuang

    2008-01-01

    In this study, a new technique of air cleaning by plasma combined with catalyst was proposed, which consisted of electrostatic precipitation, volatile organic compounds (VOCs) decomposition and sterilization. A novel indoor air purifier based on this technique was adopted. The experimental results showed that formaldehyde decomposition by the plasma-catalyst hybrid system was more efficient than that by plasma only. Positive discharge was better than negative discharge in formaldehyde removal. Meanwhile, the outlet concentration of ozone byproduct was effectively reduced by the nano-titania catalyst.

  15. Experimental study of laser ablation as sample introduction technique for inductively coupled plasma-mass spectrometry

    International Nuclear Information System (INIS)

    Van Winckel, S.

    2001-01-01

    The contribution consists of an abstract of a PhD thesis. In the PhD study, several complementary applications of laser-ablation were investigated in order to characterise experimentally laser ablation (LA) as a sample introduction technique for ICP-MS. Three applications of LA as a sample introduction technique are discussed: (1) the microchemical analysis of the patina of weathered marble; (2) the possibility to measure isotope ratios (in particular Pb isotope ratios in archaeological bronze artefacts); and (3) the determination of Si in Al as part of a dosimetric study of the BR2 reactor vessel

  16. Experimental study on the evolution of Peregrine breather with uniform-depth adverse currents

    Science.gov (United States)

    Liao, B.; Ma, Y.; Ma, X.; Dong, G.

    2018-05-01

    A series of laboratory experiments were performed to study the evolution of Peregrine breather (PB) in a wave flume in finite depth, and wave trains were initially generated in a region of quiescent water and then propagated into an adverse current region for which the current velocity strength gradually increased from zero to an approximately stable value. The PB is often considered as a prototype of oceanic freak waves that can focus wave energy into a single wave packet. In the experiment, the cases were selected with the relative water depths k0h (k0 is the wave number in quiescent water and h is the water depth) varying from 3.11 through 8.17, and the initial wave steepness k0a0 (a0 is the background wave amplitude) ranges between 0.065 and 0.120. The experimental results show the persistence of the breather evolution dynamics even in the presence of strong opposing currents. We have shown that the characteristic spectrum of the PB persists even on strong currents, thus making it a viable characteristic for prediction of freak waves. It was also found that the adverse currents tend to shift the focusing point upstream compared to the cases without currents. Furthermore, it was found that uniform-depth adverse currents can reduce the breather extension in time domain.

  17. Multislice Spiral Computed Tomography of the Heart: Technique, Current Applications, and Perspective

    International Nuclear Information System (INIS)

    Mahnken, Andreas H.; Wildberger, Joachim E.; Koos, Ralf; Guenther, Rolf W.

    2005-01-01

    Multislice spiral computed tomography (MSCT) is a rapidly evolving, noninvasive technique for cardiac imaging. Knowledge of the principle of electrocardiogram-gated MSCT and its limitations in clinical routine are needed to optimize image quality. Therefore, the basic technical principle including essentials of image postprocessing is described. Cardiac MSCT imaging was initially focused on coronary calcium scoring, MSCT coronary angiography, and analysis of left ventricular function. Recent studies also evaluated the ability of cardiac MSCT to visualize myocardial infarction and assess valvular morphology. In combination with experimental approaches toward the assessment of aortic valve function and myocardial viability, cardiac MSCT holds the potential for a comprehensive examination of the heart using one single examination technique

  18. A new circuit technique for reduced leakage current in Deep Submicron CMOS technologies

    Directory of Open Access Journals (Sweden)

    A. Schmitz

    2005-01-01

    Full Text Available Modern CMOS processes in the Deep Submicron regime are restricted to supply voltages below 2 volts and further to account for the transistors' field strength limitations and to reduce the power per logic gate. To maintain the high switching performance, the threshold voltage must be scaled according with the supply voltage. However, this leads to an increased subthreshold current of the transistors in standby mode (VGS=0. Another source of leakage is gate current, which becomes significant for gate oxides of 3nm and below. We propose a Self-Biasing Virtual Rails (SBVR - CMOS technique which acts like an adaptive local supply voltage in case of standby mode. Most important sources of leakage currents are reduced by this technique. Moreover, SBVR-CMOS is capable of conserving stored information in sleep mode, which is vital for memory circuits. Memories are exposed to radiation causing soft errors. This well-known problem becomes even worse in standby mode of typical SRAMs, that have low driving performance to withstand alpha particle hits. In this paper, a 16-transistor SRAM cell is proposed, which combines the advantage of extremely low leakage currents with a very high soft error stability.

  19. Experimental study of gas-cooled current leads for superconducting magnets

    International Nuclear Information System (INIS)

    Warren, R.P.

    1978-04-01

    Design details and experimental test results from several design variations of the gas-cooled, copper current leads used in conjunction with the superconducting dipole magnets for ESCAR (Experimental Superconducting Accelerator Ring) are reported. Thermal acoustic oscillations, which were experienced with an initial design, were eliminated in subsequent designs by a reduction of the hydraulic diameter. The occurrence of these oscillations is in general agreement with the stability analysis of Rott but the observed gas flow dependence is not in agreement with some other recently reported results for leads operated supercritical phase coolant. An empirically determined correlation was obtained by plotting lead resistance vs. enthalpy gain of the coolant gas. The resulting family of curves can be reduced to a single line on a plot of effective resistivity vs. the product of current and cross-sectional area divided by the product of the square of the mass flow of the coolant and the lead length. This correlation, which should be applicable to other designs of copper current leads in which ideal heat transfer to the coolant gas is approached, predicts that the enthalpy gain of the coolant, and therefore the peak lead temperature, is proportional to the cube of the ratio of current to coolant mass flow. The effective value of the strongly temperature-dependent kinematic viscosity of the coolant gas was found to vary linearly with the effective resistivity of the lead

  20. Progress in nuclear measuring and experimental techniques by application of microelectronics. 1

    International Nuclear Information System (INIS)

    Meiling, W.

    1984-01-01

    In the past decade considerable progress has been made in nuclear measuring and experimental techniques by developing position-sensitive detector systems and widely using integrated circuits and microcomputers for data acquisition and processing as well as for automation of measuring processes. In this report which will be published in three parts those developments are reviewed and demonstrated on selected examples. After briefly characterizing microelectronics, the use of microelectronic elements for radiation detectors is reviewed. (author)

  1. Current status of molecular biological techniques for plant breeding in the Republic of Korea

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Seong-Han; Lee, Si-Myung; Park, Bum-Seok; Yun, In-Sun; Goo, Doe-Hoe; Kim, Seok-Dong [Rural Development Administration, National Institute of Agricultural Science and Technology, Suwon (Korea)

    2002-02-01

    Classical plant breeding has played an important role in developing new varieties in current agriculture. For decades, the technique of cross-pollination has been popular for breeding in cereal and horticultural crops to introduce special traits. However, recently the molecular techniques get widely accepted as an alternative tool in both introducing a useful trait for developing the new cultivars and investigating the characteristics of a trait in plant, like the identification of a gene. Using the advanced molecular technique, several genetically modified (GM) crops (e.g., Roundup Ready Soybean, YieldGard, LibertyLink etc.) became commercially cultivated and appeared in the global market since 1996. The GM crops, commercially available at the moment, could be regarded as successful achievements in history of crop breeding conferring the specific gene into economically valuable crops to make them better. Along with such achievements, on the other hand these new crops have also caused the controversial debate on the safety of GM crops as human consumption and environmental release as well. Nevertheless, molecular techniques are widespread and popular in both investigating the basic science of plant biology and breeding new varieties compared to their conventional counterparts. Thus, the Department of Bioresources at the National Institute of Agricultural Science and Technology (NIAST) has been using the molecular biological techniques as a complimentary tool for the improvement of crop varieties for almost two decades. (author)

  2. Current Needs for the Experimental Investigation of the CHF Phenomenon Relevant to LWR Core Conditions

    International Nuclear Information System (INIS)

    Le Corre, J.M.

    2009-01-01

    The current achievements and needs toward the investigation, understanding and mechanistic prediction of the Critical Heat Flux (CHF) event, under PWR and BWR core conditions, are addressed in this paper. It is shown that, even when using advanced 3-D CFD simulation tools, the current approach to CHF mechanistic modeling has serious limitations. This is mainly due to the lack of information regarding the relevant two-phase flow pattern(s) (in particular near the heated wall) and associated mechanisms (at the meso and micro-scale) leading to the CHF event. Areas of current experimental needs are identified in order to address these shortcomings. In addition, the use of 1-D and 3-D numerical tools to mechanistically predict the CHF is discussed. It is shown that 3-D two-phase CFD codes may not be superior to 1-D codes without proper consideration of relevant constitutive relations. (author)

  3. Experimental technique to measure thoron generation rate of building material samples using RAD7 detector

    International Nuclear Information System (INIS)

    Csige, I.; Szabó, Zs.; Szabó, Cs.

    2013-01-01

    Thoron ( 220 Rn) is the second most abundant radon isotope in our living environment. In some dwellings it is present in significant amount which calls for its identification and remediation. Indoor thoron originates mainly from building materials. In this work we have developed and tested an experimental technique to measure thoron generation rate in building material samples using RAD7 radon-thoron detector. The mathematical model of the measurement technique provides the thoron concentration response of RAD7 as a function of the sample thickness. For experimental validation of the technique an adobe building material sample was selected for measuring the thoron concentration at nineteen different sample thicknesses. Fitting the parameters of the model to the measurement results, both the generation rate and the diffusion length of thoron was estimated. We have also determined the optimal sample thickness for estimating the thoron generation rate from a single measurement. -- Highlights: • RAD7 is used for the determination of thoron generation rate (emanation). • The described model takes into account the thoron decay and attenuation. • The model describes well the experimental results. • A single point measurement method is offered at a determined sample thickness

  4. Analysis techniques of charging damage studied on three different high-current ion implanters

    Science.gov (United States)

    Felch, S. B.; Larson, L. A.; Current, M. I.; Lindsey, D. W.

    1989-02-01

    One of the Greater Silicon Valley Implant Users' Group's recent activities has been to sponsor a round-robin on charging damage, where identical wafers were implanted on three different state-of-the-art, high-current ion implanters. The devices studied were thin-dielectric (250 Å SiO2), polysilicon-gate MOS capacitors isolated by thick field oxide. The three implanters involved were the Varian/Extrion 160XP, the Eaton/Nova 10-80, and the Applied Materials PI9000. Each implanter vendor was given 48 wafers to implant with 100 keV As+ ions at a dose of 1 × 1016 cm-2. Parameters that were varied include the beam current, electron flood gun current, and chamber pressure. The charge-to-breakdown, breakdown voltage, and leakage current of several devices before anneal have been measured. The results from these tests were inconclusive as to the physical mechanism of charging and as to the effectiveness of techniques to reduce its impact on devices. However, the methodology of this study is discussed in detail to aid in the planning of future experiments. Authors' industrial affiliations: S.B. Felch, Varian Research Center, 611 Hansen Way, Palo Alto, CA 94303, USA; L.A. Larson, National Semiconductor Corp., P.O. Box 58090, Santa Clara, CA 95052-8090, USA; M.I. Current, Applied Materials, 3050 Bowers Ave., Santa Clara, CA 95054, USA; D.W. Lindsey, Eaton/NOVA, 931 Benicia Ave, Sunnyvale, CA 94086, USA.

  5. They see a rat, we seek a cure for diseases: the current status of animal experimentation in medical practice.

    Science.gov (United States)

    Kehinde, Elijah O

    2013-01-01

    The objective of this review article was to examine current and prospective developments in the scientific use of laboratory animals, and to find out whether or not there are still valid scientific benefits of and justification for animal experimentation. The PubMed and Web of Science databases were searched using the following key words: animal models, basic research, pharmaceutical research, toxicity testing, experimental surgery, surgical simulation, ethics, animal welfare, benign, malignant diseases. Important relevant reviews, original articles and references from 1970 to 2012 were reviewed for data on the use of experimental animals in the study of diseases. The use of laboratory animals in scientific research continues to generate intense public debate. Their use can be justified today in the following areas of research: basic scientific research, use of animals as models for human diseases, pharmaceutical research and development, toxicity testing and teaching of new surgical techniques. This is because there are inherent limitations in the use of alternatives such as in vitro studies, human clinical trials or computer simulation. However, there are problems of transferability of results obtained from animal research to humans. Efforts are on-going to find suitable alternatives to animal experimentation like cell and tissue culture and computer simulation. For the foreseeable future, it would appear that to enable scientists to have a more precise understanding of human disease, including its diagnosis, prognosis and therapeutic intervention, there will still be enough grounds to advocate animal experimentation. However, efforts must continue to minimize or eliminate the need for animal testing in scientific research as soon as possible. © 2013 S. Karger AG, Basel.

  6. A 540-[Formula: see text] Duty Controlled RSSI With Current Reusing Technique for Human Body Communication.

    Science.gov (United States)

    Jang, Jaeeun; Lee, Yongsu; Cho, Hyunwoo; Yoo, Hoi-Jun

    2016-08-01

    An ultra-low-power duty controlled received signal strength indicator (RSSI) is implemented for human body communication (HBC) in 180 nm CMOS technology under 1.5 V supply. The proposed RSSI adopted 3 following key features for low-power consumption; 1) current reusing technique (CR-RSSI) with replica bias circuit and calibration unit, 2) duty controller, and 3) reconfigurable gm-boosting LNA. The CR-RSSI utilizes stacked amplifier-rectifier-cell (AR-cell) to reuse the supply current of each blocks. As a result, the power consumption becomes 540 [Formula: see text] with +/-2 dB accuracy and 75 dB dynamic range. The replica bias circuit and calibration unit are adopted to increase the reliability of CR-RSSI. In addition, the duty controller turns off the RSSI when it is not required, and this function leads 70% power reduction. At last, the gm-boosting reconfigurable LNA can adaptively vary its noise and linearity performance with respect to input signal strength. Fro current reusing technique m this feature, we achieve 62% power reduction in the LNA. Thanks to these schemes, compared to the previous works, we can save 70% of power in RSSI and LNA.

  7. The development of human factors experimental evaluation techniques -The development of human factors technologies-

    International Nuclear Information System (INIS)

    Sim, Bong Shick; Oh, In Seok; Cha, Kyeong Ho; Lee, Hyun Chul

    1994-04-01

    In the 2nd year of the research project for the development of human factors evaluation techniques, we first defined the experimental target systems by the comparison study of the advanced control rooms proposed by foreign countries in order to make the experiment feasible and realistic for the 10 experimental items selected in the first year of the project. Then we have decided to confine our research on the big board overview panel and operator workstations. Following the development of selection criteria for our research interest, we have identified the design variables which may influence the performance of the operator by the functional analysis. The experimental variables which will be used for the evaluation of the proposed items are then defined by the relational analysis between evaluation items and design variables and they are classified by the characteristics of the measurement data. The functional requirements of ITF are developed to accommodate the necessary functions for carrying out the 10 evaluation items. The functional requirements for each sub-system of ITF have been developed with the experimental paradigm of APTEA. Finally we have reviewed the compact nuclear simulator (CNS) at KAERI from the point of view of jyman factors guidelines/principles and proposed the two possible layouts for the experimental apparatus for the evaluation of display alternative and operational procedure. (Author)

  8. Experimental Irradiations of Materials and Fuels in the BR2 Reactor: An Overview of Current Programmes

    International Nuclear Information System (INIS)

    Van Dyck, S.; Koonen, E.; Verwerft, M.; Wéber, M.

    2013-01-01

    The BR2 material test reactor offers a variety of experimental irradiation possibilities for testing of materials, fuels and instruments. The current paper gives an overview of the recent and ongoing programmes in order to illustrate the experimental potential of the reactor. Three domains of applications are reviewed: Irradiation of materials and fuels for pressurised water reactors (PWR); irradiation of materials for accelerator driven systems (ADS), cooled by liquid lead alloys; and irradiation of fuel for Material Test Reactors (MTR). For PWR relevant tests, a dedicated loop is available, providing a full simulation of the thermo hydraulic conditions of a PWR. ADS related tests require particular control of the irradiation environment and the necessary safety precautions in order to avoid 210 Po contamination. In-core mechanical testing of materials is done in comparison and complimentarily to post-irradiation examinations in order to assess flux related effects on the deformation behaviour of materials. (author)

  9. An overview of MR arthrography with emphasis on the current technique and applicational hints and tips

    International Nuclear Information System (INIS)

    Sahin, Guelden; Demirtas, Mehmet

    2006-01-01

    Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established

  10. An overview of MR arthrography with emphasis on the current technique and applicational hints and tips

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Guelden [Department of Radiology, Faculty of Medicine, Ankara University, Samanpazari, 06100 Ankara (Turkey)]. E-mail: gsahin@medicine.ankara.edu.tr; Demirtas, Mehmet [Department of Hand Surgery, Faculty of Medicine, Ankara University, Samanpazari, 06100 Ankara (Turkey)

    2006-06-15

    Magnetic resonance (MR) arthrography has been investigated in every major peripheral joint of the body, and has been proven to be effective in determining the integrity of intraarticular ligamentous and fibrocartilaginous structures and in the detection or assessment of osteochondral lesions and loose bodies in selected cases. Several methods could be used to create arthrogram effect during MR imaging, however, direct MR arthrography using diluted gadolinium as the contrast agent is the most commonly used technique and is the most reliable of all. MR arthrography is useful for demonstrating labrocapsular-ligamentous abnormalities and distinguishing partial thickness rotator cuff tears from focal full thickness tears in the shoulder, identifying or excluding recurrent tears following meniscal operations in the knee, demonstrating perforations of the triangular fibrocartilage complex (TFCC) and ligaments in the wrist, showing labral tears in the hip, diagnosing ligament tears in the ankle and identifying osteochondral lesions or loose bodies in any of the aforementioned joints. In this article, an overview of techniques of MR arthrography is provided with emphasis on direct MR arthrography using diluted gadolinium as the contrast agent. The current applications of the technique in major peripheral joints are reviewed, with emphasis given to the shoulder joint where the role of this technique has become well established.

  11. Sensor Fusion Techniques for Phased-Array Eddy Current and Phased-Array Ultrasound Data

    Energy Technology Data Exchange (ETDEWEB)

    Arrowood, Lloyd F. [Y-12 National Security Complex, Oak Ridge, TN (United States)

    2018-03-15

    Sensor (or Data) fusion is the process of integrating multiple data sources to produce more consistent, accurate and comprehensive information than is provided by a single data source. Sensor fusion may also be used to combine multiple signals from a single modality to improve the performance of a particular inspection technique. Industrial nondestructive testing may utilize multiple sensors to acquire inspection data depending upon the object under inspection and the anticipated types of defects that can be identified. Sensor fusion can be performed at various levels of signal abstraction with each having its strengths and weaknesses. A multimodal data fusion strategy first proposed by Heideklang and Shokouhi that combines spatially scattered detection locations to improve detection performance of surface-breaking and near-surface cracks in ferromagnetic metals is shown using a surface inspection example and is then extended for volumetric inspections. Utilizing data acquired from an Olympus Omniscan MX2 from both phased array eddy current and ultrasound probes on test phantoms, single and multilevel fusion techniques are employed to integrate signals from the two modalities. Preliminary results demonstrate how confidence in defect identification and interpretation benefit from sensor fusion techniques. Lastly, techniques for integrating data into radiographic and volumetric imagery from computed tomography are described and results are presented.

  12. High Accuracy Beam Current Monitor System for CEBAF'S Experimental Hall A

    International Nuclear Information System (INIS)

    J. Denard; A. Saha; G. Lavessiere

    2001-01-01

    CEBAF accelerator delivers continuous wave (CW) electron beams to three experimental Halls. In Hall A, all experiments require continuous, non-invasive current measurements and a few experiments require an absolute accuracy of 0.2 % in the current range from 1 to 180 (micro)A. A Parametric Current Transformer (PCT), manufactured by Bergoz, has an accurate and stable sensitivity of 4 (micro)A/V but its offset drifts at the muA level over time preclude its direct use for continuous measurements. Two cavity monitors are calibrated against the PCT with at least 50 (micro)A of beam current. The calibration procedure suppresses the error due to PCT's offset drifts by turning the beam on and off, which is invasive to the experiment. One of the goals of the system is to minimize the calibration time without compromising the measurement's accuracy. The linearity of the cavity monitors is a critical parameter for transferring the accurate calibration done at high currents over the whole dynamic range. The method for measuring accurately the linearity is described

  13. Recent Advances in Simulation of Eddy Current Testing of Tubes and Experimental Validations

    Science.gov (United States)

    Reboud, C.; Prémel, D.; Lesselier, D.; Bisiaux, B.

    2007-03-01

    Eddy current testing (ECT) is widely used in iron and steel industry for the inspection of tubes during manufacturing. A collaboration between CEA and the Vallourec Research Center led to the development of new numerical functionalities dedicated to the simulation of ECT of non-magnetic tubes by external probes. The achievement of experimental validations led us to the integration of these models into the CIVA platform. Modeling approach and validation results are discussed here. A new numerical scheme is also proposed in order to improve the accuracy of the model.

  14. Experimental techniques for the detection of the high energy gamma rays of cosmic origin

    International Nuclear Information System (INIS)

    Dumitrescu, Gh.; Angelescu, T.; Radu, A.A.

    2002-01-01

    The observation of high energy gamma rays of cosmic origin in the early 90 by Volcano Ranch experiment opened a new direction of study in astrophysics. The very high energy and the very low flux of these gamma rays, posed numerous detection problems which in turn were the object of a very intense research activity. The present article tries to review the detection techniques for the high energy gamma rays of cosmic origin. In the 'Introduction' we summarize the specific problems involved in the detection of this type of radiation. 'Chapter 1' presents the classic technique based on the use of scintillation detectors. 'Chapter 2' includes the imaging atmospheric Cherenkov technique (IACT) and the sampling wavefront technique. 'Chapter 3' is dedicated to the detection of the atmospheric nitrogen. 'Chapter 4' describes issues related to the calibration of the detectors, the cross checking of the experimental data, the use of the Monte Carlo simulations and the use of the density observed at a distance of 600 m S(600), in order to estimate the primary energy. The characteristics of some future developments of the above presented techniques are included in the last chapter. (authors)

  15. Analysis of Current Visualization Techniques and Main Challenges for the Future

    Directory of Open Access Journals (Sweden)

    Manuel Pérez Cota

    2017-08-01

    Full Text Available The big amount of data generated nowadays are being used by Big Data tools to generate knowledge and to facilitate the decision-making. However, this situation creates a new challenge: how to visualize all these data without losing mid/long term crucial information. The purpose of this article is to analyze the state of the art on massive data visualization, main problems and challenges of information representation current techniques as well as the evolution of the tools and the future of them, in other words, new functionalities to offer.

  16. Feedback control of persistent-current oscillation based on the atomic-clock technique

    Science.gov (United States)

    Yu, Deshui; Dumke, Rainer

    2018-05-01

    We propose a scheme of stabilizing the persistent-current Rabi oscillation based on the flux qubit-resonator-atom hybrid structure. The low-Q L C resonator weakly interacts with the flux qubit and maps the persistent-current Rabi oscillation of the flux qubit onto the intraresonator electric field. This oscillating electric field is further coupled to a Rydberg-Rydberg transition of the 87Rb atoms. The Rabi-frequency fluctuation of the flux qubit is deduced from measuring the atomic population via the fluorescence detection and stabilized by feedback controlling the external flux bias. Our numerical simulation indicates that the feedback-control method can efficiently suppress the background fluctuations in the flux qubit, especially in the low-frequency limit. This technique may be extensively applicable to different types of superconducting circuits, paving a way to long-term-coherence superconducting quantum information processing.

  17. Hysteresis current control technique of VSI for compensation of grid-connected unbalanced loads

    DEFF Research Database (Denmark)

    Pouresmaeil, Edris; Akorede, Mudathir Funsho; Montesinos-Miracle, Daniel

    2014-01-01

    interconnection issues that usually arise as DG units connect to the electric grid. The proposed strategy, implemented in Matlab/Simulink environment in different operating scenarios, provides compensation for active, reactive, unbalanced, and harmonic current components of grid-connected nonlinear unbalanced...... resources as they connect to the exiting power grid could provoke many power quality problems on the grid side. For this reason, due considerations must be given to power generation and safe running before DG units is actually integrated into the power grid. The main aim of this paper is to address the grid...... loads. The simulation results obtained in this study demonstrate the level of accuracy of the proposed technique, which ensure a balance in the overall grid phase currents, injection of maximum available power from DG resources to the grid, improvement of the utility grid power factor, and a reduction...

  18. Current literature and imaging techniques of aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL)

    International Nuclear Information System (INIS)

    Duggan, P.J.; Burke, C.J.; Saha, S.; Moonim, M.; George, M.; Desai, A.; Houghton, R.

    2013-01-01

    Aseptic lymphocyte-dominated vasculitis-associated lesions (ALVAL) are a recognized complication of metal-on-metal bearing hip prostheses. There is an impending concern regarding the future investigation and management of patients who have received such implants. The current literature is discussed, and the current guidelines for management of these patients in the UK are reviewed. The various imaging techniques available, such as computed tomography, metal artefact reduction magnetic resonance imaging, and ultrasound are discussed and evaluated with respect to the assessment of patients with suspected ALVAL. The histopathological findings are discussed with images of the tissue changes provided. Images of the radiological findings are also provided for all general radiological methods. ALVAL and its radiological presentation is an important issue that unfortunately may become a significant clinical problem

  19. Experimental measurements of the eddy current signal due to a flawed, conducting half space

    International Nuclear Information System (INIS)

    Long, S.A.; Toomsawasdi, S.; Zaman, A.J.M.

    1984-01-01

    This chapter reports on an experimental investigation in which the change in impedance of a practical multi-turn eddy current coil near a conducting half space is measured as a function of the conductivity and the lift-off distance. The results are compared in a qualitative fashion with the analytical results for a single-turn coil. Measurements are also made of the change in impedance due to a small void in the conducting half space as a function of both its depth and radial position. The results indicate that, at least in a qualitative fashion, the precisely derived analytical solutions adequately predict the general behavior of the change in complex impedance of an eddy current coil above a conducting ground plane as a function of lift-off distance. It is determined that the effect of a sub-surface void on the change in inductance of the test coil correlates well with theoretical calculations

  20. Experimental study on flaw detectability of remote field eddy current testing

    International Nuclear Information System (INIS)

    Kamimura, T.; Fukui, S.; Iwahashi, Y.; Yamada, H.

    1988-01-01

    For the purpose of comprehending the effect in practical use of the remote field eddy current (RFEC) testing that becomes noticeable for the ISI technique of steel tubes, its flaw detectability was clarified through a model test. This study used straight and bending tubes of 3.8 mm in wall thickness and 31.8 mm in outside diameter. These tubes were inspected from their inside. After relations among the pickup coil output, coil distance, testing frequency, etc. were measured, a probe of the practical use type was manufactured to investigate its flaw detectability by means of simulated flaws. The authors discuss how it has been found that light local wall thinning on the outside surfaces can be detected by this technique and its effect in practical use can be expected with small influences due to magnetic permeability variations of tube materials, bending of tubes, etc

  1. Characterization of Elastic and Plastic Behaviors in Steel Plate Based on Eddy Current Technique Using a Portable Impedance Analyzer

    Directory of Open Access Journals (Sweden)

    Meng Fanlin

    2017-01-01

    Full Text Available A portable impedance analyzer (PIA was developed based on a TiePie-HS3 device to provide the comparable impedance measurement accuracy of the Agilent 4294a impedance analyzer in the frequency range of 0~250 kHz. Then the PIA was applied to monitor the tensile stress-induced variation of the eddy current sensor’s impedance in a medium-carbon steel sample. A model of equivalent magnetic field induced by the elastic stress and the number of pinning sites indicated that the inductance of the eddy current loop firstly increased with the increase in the tensile stress and then decreased at the yield point of the material. The experimental results testified that the variation of impedance amplitude, the variation of phase angle, and the shift of two featured frequencies demonstrated opposite variation trends before and after the yield point, as predicated by the model. A new parameter, which combined the impedance variation information of the selected two frequencies, was found to exhibit nearly monotonous dependency on the tensile stress in elastic and plastic stages. The new parameter together with the developed portable impedance analyzer provided the solution to identify the elastic and plastic behaviors in ferromagnetic materials in practical applications with an eddy current technique.

  2. Laboratory experiment on the 3D tide-induced Lagrangian residual current using the PIV technique

    Science.gov (United States)

    Chen, Yang; Jiang, Wensheng; Chen, Xu; Wang, Tao; Bian, Changwei

    2017-12-01

    The 3D structure of the tide-induced Lagrangian residual current was studied using the particle image velocimetry (PIV) technique in a long shallow narrow tank in the laboratory. At the mouth of the tank, a wave generator was used to make periodic wave which represents the tide movement, and at the head of the tank, a laterally sloping topography with the length of one fifth of the water tank was installed, above which the tide-induced Lagrangian residual current was studied. Under the weakly nonlinear condition in the present experiment setup, the results show that the Lagrangian residual velocity (LRV) field has a three-layer structure. The residual current flows inwards (towards the head) in the bottom layer and flows outwards in the middle layer, while in the surface layer, it flows inwards along the shallow side of the sloping topography and outwards along the deep side. The depth-averaged and breadth-averaged LRV are also analyzed based on the 3D LRV observations. Our results are in good agreement with the previous experiment studies, the analytical solutions with similar conditions and the observational results in real bays. Moreover, the volume flux comparison between the Lagrangian and Eulerian residual currents shows that the Eulerian residual velocity violates the mass conservation law while the LRV truly represents the inter-tidal water transport. This work enriches the laboratory studies of the LRV and offers valuable references for the LRV studies in real bays.

  3. Applications of pulsed Eddy Current (PEC) technique on defect and material assessment

    International Nuclear Information System (INIS)

    Nurul A'in Ahmad Latif; Noorhazleena Azaman; Ilham Mukriz Zainal Abidin

    2014-01-01

    The pulsed eddy current (PEC) is an emerging electromagnetic method and widely used in multiple field including aerospace, petrochemical, industry and transportation. PEC mainly depends on the multiple variables such as peak value and rising time to detect and quantify the defects. Apart of its advantage as non contacting technique, it has ability on conducting surface and subsurface detection. Additionally, PEC is high sensitive to variety parameters that are inherent in the flaws. Compare to conventional eddy current, PEC allows deeper penetration as it is a combination from multiple frequencies. This paper demonstrates the abilities of PEC technique performing multiple testing in various fields such as conducting conductivity testing, measuring the material thickness and identifying depth of the defects. The conductivity testing will be performed on multiple materials such as aluminium, stainless steel, copper, austenitic steel and titanium. To measure the material thicknesses, PEC testing will be conducted on the multi layered specimen with the different thickness. Meanwhile to identify depth of defects, the testing will be carried out using a stainless steel calibration block contains multiple length of defect. For the validation purposes, all the results generate through the experiments will be compared with simulation results produced using dedicated software, COMSOL. (author)

  4. Robot-assisted laparoscopic partial nephrectomy: Current review of the technique and literature.

    Science.gov (United States)

    Singh, Iqbal

    2009-10-01

    To visit the operative technique and to review the current published English literature on the technique, and outcomes following robot-assisted laparoscopic partial nephrectomy (RPN). We searched the published English literature and the PubMed(()) for published series of 'robotic partial nephrectomy' (RPN) using the keywords; robot, robot-assisted laparoscopic partial nephrectomy, laparoscopic partial nephrectomy, partial nephrectomy and laparoscopic surgery. The search yielded 15 major selected series of 'robotic partial nephrectomy'; these were reviewed, tracked and analysed in order to determine the current status and role of RPN in the management of early renal neoplasm(s), as a minimally invasive surgical alternative to open partial nephrectomy. A review of the initial peri-operative outcome of the 350 cases of select series of RPN reported in published English literature revealed a mean operating time, warm ischemia time, estimated blood loss and hospital stay, of 191 minutes, 25 minutes, 162 ml and 2.95 days, respectively. The overall computed mean complication rate of RPN in the present select series was about 7.4%. RPN is a safe, feasible and effective minimally invasive surgical alternative to laparoscopic partial nephrectomy for early stage (T(1)) renal neoplasm(s). It has acceptable initial renal functional outcomes without the increased risk of major complications in experienced hands. Prospective randomised, controlled, comparative clinical trials with laparoscopic partial nephrectomy (LPN) are the need of the day. While the initial oncological outcomes of RPN appear to be favourable, long-term data is awaited.

  5. Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

    International Nuclear Information System (INIS)

    Mitchard, D.; Clark, D.; Carr, D.; Haddad, A.

    2016-01-01

    A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

  6. Experimental demonstration of the finite measurement time effect on the Feynman-{alpha} technique

    Energy Technology Data Exchange (ETDEWEB)

    Wallerbos, E.J.M.; Hoogenboom, J.E

    1998-09-01

    The reactivity of a subcritical system is determined by fitting two different theoretical models to a measured Feynman-{alpha} curve. The first model is the expression usually found in the literature, which can be shown to be the expectation value of the experimental quality if the measurement time is infinite. The second model is a new expression which is the expectation value of the experimental quantity for a finite measurement time. The reactivity inferred with the new model is seen to be independent of the length of the fitting interval, whereas the reactivity inferred with the conventional model is seen to vary. This difference demonstrates the effect of the finite measurement time. As a reference, the reactivity is also measured with the pulsed-neutron source method. It is seen to be in good agreement with the reactivity obtained with the Feynman-{alpha} technique when the new expression is applied.

  7. Experimental study of natural two-phase flow circulation using a visualization technique

    International Nuclear Information System (INIS)

    Vinhas, Pedro A.M.; Su, Jian

    2013-01-01

    This paper presents an experimental study of natural two-phase flow in a circuit that simulates, on a smaller scale, a typical residual heat removal system of passive reactors APWR (Advanced Pressurized Water Reactor). The circuit was formed by a heater, a heat exchanger and piping. The experimental study was the application of a visualization technique, using a high speed camera, for measuring the size and speed of vapor bubbles generated in the heater with different power heating. The camera was positioned in the central region of the pipe connecting the heater to the heat exchanger, where there is a clear passage. The flow of images were processed and analyzed using commercial software that allowed the determination of the length and velocity of the bubbles. The results were then compared with correlations available in literature

  8. Forensic palynology: current status of a rarely used technique in the United States of America.

    Science.gov (United States)

    Bryant, Vaughn M; Jones, Gretchen D

    2006-11-22

    The United States of America would seem to be an excellent location for using pollen data in forensic applications. The vegetation within the region is highly diverse ranging from areas of Arctic tundra to some of the most inhospitable deserts anywhere in the Western Hemisphere. The highly varied ecology, great plant diversity, thousands of vegetational microhabitats, and extensive published pollen records for the region provide an ideal setting for these types of analyses. This diversity, often characterized in most locations by unique combinations of pollen types, makes the use of forensic pollen a reliable technique that can often be used to associate individuals with a unique crime scene or geographical region. Nevertheless, forensic pollen studies in the United States of America are currently one of the most highly under utilized techniques available to assist in solving criminal and civil cases. During the past century there has been a very limited attempt to use pollen evidence in either criminal or civil cases, for a variety of reasons, including a lack of available information about the technique, a very limited number of specialists trained to do forensic pollen work, and an almost total absence of academic centers able to train needed specialists or forensic facilities able, or willing, to fund research in this area. Hopefully, this paucity of use will change if certain steps are taken to encourage the routine collection and use of pollen evidence in both criminal and civil cases.

  9. Development of human factors experimental evaluation techniques - Human factors design and evaluation of the main control room of atomic power plants using visual display terminals

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sung Ho; Chung, Min Kyun; Choi, Kyung Lim; Song, Young Woong; Eoh, Hong Joon; Lee, In Suk; Kim, Bom Soo; Yeo, Yun Shin; Lee, Haeo Sun [Pohang University of Science and Technology, Pohang (Korea, Republic of)

    1995-07-01

    This study was conducted to build a prototype of the operator interface on a visual display terminal, and to provide a framework for using and applying prototyping techniques. A typical subsystem of an MCR was prototyped and validated by operator testing. Lessons learned during the development as well as prototyping techniques were described in this report for an efficient development. In addition, human factors experimental plans were surveyed and summarized for evaluating new design alternatives as well as the current design of the operator interface. The major results of this study are listed as follow: A method for designing an operator interface prototype on a VDT, A prototype of the operator interface of a typical subsystem, Guidelines for applying prototyping techniques, Characteristics and major considerations of experimental plans, Guidelines for applying prototyping techniques, Characteristics and major considerations of experimental plans, Guidelines for analyzing experimental data, A paradigm for human factors experimentation including experimental designs, procedures, and data analyses. 27 refs., 60 tabs., 47 figs. (author)

  10. A general technique for confluence of calculational and experimental information with application to power distribution determination

    International Nuclear Information System (INIS)

    Serov, I.V.; Hoogenboom, J.E.

    1994-01-01

    Physical quantities can be obtained by utilizing different informational sources. The available information is usually associated with systematic and statistical errors. If the informational sources are utilized simultaneously, then it is possible to obtain posterior estimates of the quantities with better statistical properties than exhibited by any prior estimates. The general technique for confluence of any number possibly dependent informational sources can be developed. Insight into the nature of the informational source allows different types of data associated with the source to be improved. The formulas of the technique are presented and applied to the power distribution determination for research reactor HOR of the Delft University of Technology, employing calculational and experimental data. (authors). 5 refs., 1 tab., 5 figs

  11. The coupling of high-speed high resolution experimental data and LES through data assimilation techniques

    Science.gov (United States)

    Harris, S.; Labahn, J. W.; Frank, J. H.; Ihme, M.

    2017-11-01

    Data assimilation techniques can be integrated with time-resolved numerical simulations to improve predictions of transient phenomena. In this study, optimal interpolation and nudging are employed for assimilating high-speed high-resolution measurements obtained for an inert jet into high-fidelity large-eddy simulations. This experimental data set was chosen as it provides both high spacial and temporal resolution for the three-component velocity field in the shear layer of the jet. Our first objective is to investigate the impact that data assimilation has on the resulting flow field for this inert jet. This is accomplished by determining the region influenced by the data assimilation and corresponding effect on the instantaneous flow structures. The second objective is to determine optimal weightings for two data assimilation techniques. The third objective is to investigate how the frequency at which the data is assimilated affects the overall predictions. Graduate Research Assistant, Department of Mechanical Engineering.

  12. Integration of computational modeling and experimental techniques to design fuel surrogates

    DEFF Research Database (Denmark)

    Choudhury, H.A.; Intikhab, S.; Kalakul, Sawitree

    2017-01-01

    performance. A simplified alternative is to develop surrogate fuels that have fewer compounds and emulate certain important desired physical properties of the target fuels. Six gasoline blends were formulated through a computer aided model based technique “Mixed Integer Non-Linear Programming” (MINLP...... Virtual Process-Product Design Laboratory (VPPD-Lab) are applied onto the defined compositions of the surrogate gasoline. The aim is to primarily verify the defined composition of gasoline by means of VPPD-Lab. ρ, η and RVP are calculated with more accuracy and constraints such as distillation curve...... and flash point on the blend design are also considered. A post-design experiment-based verification step is proposed to further improve and fine-tune the “best” selected gasoline blends following the computation work. Here, advanced experimental techniques are used to measure the RVP, ρ, η, RON...

  13. Experimental models of brain ischemia: a review of techniques, magnetic resonance imaging and investigational cell-based therapies

    Directory of Open Access Journals (Sweden)

    Alessandra eCanazza

    2014-02-01

    Full Text Available Stroke continues to be a significant cause of death and disability worldwide. Although major advances have been made in the past decades in prevention, treatment and rehabilitation, enormous challenges remain in the way of translating new therapeutic approaches from bench to bedside. Thrombolysis, while routinely used for ischemic stroke, is only a viable option within a narrow time window. Recently, progress in stem cell biology has opened up avenues to therapeutic strategies aimed at supporting and replacing neural cells in infarcted areas. Realistic experimental animal models are crucial to understand the mechanisms of neuronal survival following ischemic brain injury and to develop therapeutic interventions. Current studies on experimental stroke therapies evaluate the efficiency of neuroprotective agents and cell-based approaches using primarily rodent models of permanent or transient focal cerebral ischemia. In parallel, advancements in imaging techniques permit better mapping of the spatial-temporal evolution of the lesioned cortex and its functional responses. This review provides a condensed conceptual review of the state of the art of this field, from models and magnetic resonance imaging techniques through to stem cell therapies.

  14. Optimization technique applied to interpretation of experimental data and research of constitutive laws

    International Nuclear Information System (INIS)

    Grossette, J.C.

    1982-01-01

    The feasibility of identification technique applied to one dimensional numerical analysis of the split-Hopkinson pressure bar experiment is proven. A general 1-D elastic-plastic-viscoplastic computer program was written down so as to give an adequate solution for elastic-plastic-viscoplastic response of a pressure bar subjected to a general Heaviside step loading function in time which is applied over one end of the bar. Special emphasis is placed on the response of the specimen during the first microseconds where no equilibrium conditions can be stated. During this transient phase discontinuity conditions related to wave propagation are encountered and must be carefully taken into account. Having derived an adequate numerical model, then Pontryagin identification technique has been applied in such a way that the unknowns are physical parameters. The solutions depend mainly on the selection of a class of proper eigen objective functionals (cost functions) which may be combined so as to obtain a convenient numerical objective function. A number of significant questions arising in the choice of parameter adjustment algorithms are discussed. In particular, this technique leads to a two point boundary value problem which has been solved using an iterative gradient like technique usually referred to as a double operator gradient method. This method combines the classical Fletcher-Powell technique and a partial quadratic technique with an automatic parameter step size selection. This method is much more efficient than usual ones. Numerical experimentation with simulated data was performed to test the accuracy and stability of the identification algorithm and to determine the most adequate type and quantity of data for estimation purposes

  15. Comparison of QuadrapolarTM radiofrequency lesions produced by standard versus modified technique: an experimental model

    Directory of Open Access Journals (Sweden)

    Safakish R

    2017-06-01

    Full Text Available Ramin Safakish Allevio Pain Management Clinic, Toronto, ON, Canada Abstract: Lower back pain (LBP is a global public health issue and is associated with substantial financial costs and loss of quality of life. Over the years, different literature has provided different statistics regarding the causes of the back pain. The following statistic is the closest estimation regarding our patient population. The sacroiliac (SI joint pain is responsible for LBP in 18%–30% of individuals with LBP. Quadrapolar™ radiofrequency ablation, which involves ablation of the nerves of the SI joint using heat, is a commonly used treatment for SI joint pain. However, the standard Quadrapolar radiofrequency procedure is not always effective at ablating all the sensory nerves that cause the pain in the SI joint. One of the major limitations of the standard Quadrapolar radiofrequency procedure is that it produces small lesions of ~4 mm in diameter. Smaller lesions increase the likelihood of failure to ablate all nociceptive input. In this study, we compare the standard Quadrapolar radiofrequency ablation technique to a modified Quadrapolar ablation technique that has produced improved patient outcomes in our clinic. The methodology of the two techniques are compared. In addition, we compare results from an experimental model comparing the lesion sizes produced by the two techniques. Taken together, the findings from this study suggest that the modified Quadrapolar technique provides longer lasting relief for the back pain that is caused by SI joint dysfunction. A randomized controlled clinical trial is the next step required to quantify the difference in symptom relief and quality of life produced by the two techniques. Keywords: lower back pain, radiofrequency ablation, sacroiliac joint, Quadrapolar radiofrequency ablation

  16. Experimental device for obtaining calibration factor for the total count technique

    International Nuclear Information System (INIS)

    Gonçalves, Eduardo R.; Braz, Delson; Brandão, Luís Eduardo B.

    2017-01-01

    Nuclear technologies have widely used on industry plants in order to help to solve troubles processes/design or just obtain information of them. The Total Count technique for flow measurement has as main advantages: being an absolute technique, because it is independent of additional devices readings unless the directly used for recording the radioactive cloud, requiring only a single detector to provide the final result; the independence of the internal volume of the transport duct, can be applied in the presence or absence of obstructions; no restriction as to the nature of the product or material to be conveyed; it is a noninvasive technique which allows real-time diagnostics. To use Total Count Technique, knowledge of a geometric calibration factor is required. Called Factor F, it is obtained in the laboratory using an experimental apparatus to faithfully reproduce the geometry of the detection system and the pipeline that being analyzed and using the same radiotracer, therefore, its value is constant for each specific measuring system under survey. This experimental apparatus for obtaining the factor F consisting by a pipe of 2 ″PVC, which simulates a transmission line, where they were deposited 500 ml oil and the use of a specific pipette for use viscous fluids were added sequentially aliquots (50.00 ± 0.01) μl radiotracer (radionuclide photopeak energy of 198 Au 411.8 keV) and analyzing data obtained by three distinct detection systems composed of detectors NaI scintillators 1″ x 1 ″ and a data acquisition system. (author)

  17. Experimental device for obtaining calibration factor for the total count technique

    Energy Technology Data Exchange (ETDEWEB)

    Gonçalves, Eduardo R.; Braz, Delson [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Brandão, Luís Eduardo B. [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Divisao de Reatores

    2017-07-01

    Nuclear technologies have widely used on industry plants in order to help to solve troubles processes/design or just obtain information of them. The Total Count technique for flow measurement has as main advantages: being an absolute technique, because it is independent of additional devices readings unless the directly used for recording the radioactive cloud, requiring only a single detector to provide the final result; the independence of the internal volume of the transport duct, can be applied in the presence or absence of obstructions; no restriction as to the nature of the product or material to be conveyed; it is a noninvasive technique which allows real-time diagnostics. To use Total Count Technique, knowledge of a geometric calibration factor is required. Called Factor F, it is obtained in the laboratory using an experimental apparatus to faithfully reproduce the geometry of the detection system and the pipeline that being analyzed and using the same radiotracer, therefore, its value is constant for each specific measuring system under survey. This experimental apparatus for obtaining the factor F consisting by a pipe of 2 ″PVC, which simulates a transmission line, where they were deposited 500 ml oil and the use of a specific pipette for use viscous fluids were added sequentially aliquots (50.00 ± 0.01) μl radiotracer (radionuclide photopeak energy of 198 Au 411.8 keV) and analyzing data obtained by three distinct detection systems composed of detectors NaI scintillators 1″ x 1 ″ and a data acquisition system. (author)

  18. An experimental technique for the modelling of air flow movements in nuclear plant

    International Nuclear Information System (INIS)

    Ainsworth, R.W.; Hallas, N.J.

    1986-01-01

    This paper describes an experimental technique developed at Harwell to model ventilation flows in plant at 1/5th scale. The technique achieves dynamic similarity not only for forced convection imposed by the plant ventilation system, but also for the interaction between natural convection (from heated objects) and forced convection. The use of a scale model to study flow of fluids is a well established technique, relying upon various criteria, expressed in terms of dimensionless numbers, to achieve dynamic similarity. For forced convective flows, simulation of Reynolds number is sufficient, but to model natural convection and its interaction with forced convection, the Rayleigh, Grashof and Prandtl numbers must be simulated at the same time. This paper describes such a technique, used in experiments on a hypothetical glove box cell to study the interaction between forced and natural convection. The model contained features typically present in a cell, such as a man, motor, stairs, glove box, etc. The aim of the experiment was to study the overall flow patterns, especially around the model man 'working' at the glove box. The cell ventilation was theoretically designed to produce a downward flow over the face of the man working at the glove box. However, the results have shown that the flow velocities produced an upwards flow over the face of the man. The work has indicated the viability of modelling simultaneously the forced and natural convection processes in a cell. It has also demonstrated that simplistic assumptions cannot be made about ventilation flow patterns. (author)

  19. Experimental techniques for characterising water in wood covering the range from dry to fully water-saturated

    DEFF Research Database (Denmark)

    Thybring, Emil Engelund; Kymäläinen, Maija; Rautkari, Lauri

    2018-01-01

    focuses on selected experimental techniques that can give deeper insights into various aspects of water in wood in the entire moisture domain from dry to fully water-saturated. These techniques fall into three broad categories: (1) gravimetric techniques that determine how much water is absorbed, (2...

  20. Comparison of experimental target currents with analytical model results for plasma immersion ion implantation

    International Nuclear Information System (INIS)

    En, W.G.; Lieberman, M.A.; Cheung, N.W.

    1995-01-01

    Ion implantation is a standard fabrication technique used in semiconductor manufacturing. Implantation has also been used to modify the surface properties of materials to improve their resistance to wear, corrosion and fatigue. However, conventional ion implanters require complex optics to scan a narrow ion beam across the target to achieve implantation uniformity. An alternative implantation technique, called Plasma Immersion Ion Implantation (PIII), immerses the target into a plasma. The ions are extracted from the plasma directly and accelerated by applying negative high-voltage pulses to the target. An analytical model of the voltage and current characteristics of a remote plasma is presented. The model simulates the ion, electron and secondary electron currents induced before, during and after a high voltage negative pulse is applied to a target immersed in a plasma. The model also includes analytical relations that describe the sheath expansion and collapse due to negative high voltage pulses. The sheath collapse is found to be important for high repetition rate pulses. Good correlation is shown between the model and experiment for a wide variety of voltage pulses and plasma conditions

  1. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    OpenAIRE

    Li Yuting; Gan Fangji; Wan Zhengjun; Liao Junbi; Li Wenqiang

    2015-01-01

    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 s...

  2. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

    Science.gov (United States)

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-01-01

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

  3. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

    Directory of Open Access Journals (Sweden)

    Yunze Xu

    2016-09-01

    Full Text Available In this paper, a new kind of carbon steel (CS and stainless steel (SS galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER method and zero resistance ammeter (ZRA technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete.

  4. Experimental study of biotin-avidin pretargeting technique for anti-CEA McAb radioimmunoimaging

    International Nuclear Information System (INIS)

    Sun Jianzhong; Zhu Chengmo; Guan Liang; Li Biao; Zhang Jixian; Shi Ailan; Zhang Suyin

    1996-01-01

    Biotin-avidin pretargeting technique was used in promoting the diagnostic efficacy of anti-CEA McAb radioimmunoimaging. CEA McAb was conjugated with biotin McAb (B-McAb), streptavidin (SA) was labeled with 131 I ( 131 I-SA) and DTPA-biotin with 111 In( 111 In-DTPA-B). Experimental human colonic tumor bearing nude mice were used. Two step method: B-McAb was preinjected, followed by 131 I SA 48h later, 24, 48, 96 and 120 h postinjection, γ-imaging and biodistribution were studied. Three step method: B-McAb was preinjected, followed by cold SA 24h later and 111 In-DTPA-B another 24h later. 2,6,24 and 48h postinjection, γ-imaging and biodistribution were also studied. Two step method: T/NT of all organs in experimental group was significantly increased compared with controls. The blood T/NT in experimental group and control group at 24 and 120h was 1.11:0.42 and 8.58:3.51, respectively. Tumor % ID/g in all organs slightly decreased compared with direct group. In γ-imaging radioactivity has been accumulated in tumor site as early as 24h, while only slightly visualized or non-visualized in controls. Three step method: in experimental group the blood T/NT reached 4.19 at 2 h, whereas all was < 1.37 at each phase of controls, the T/NT of all organs was also higher in experimental grouped than in controls. The tumor % ID/g in experimental group was 9.72% at 2h and 3.65% at 48h whereas % ID/g in controls in all phases was <3.07. The tumor clearly visualized at 2h and clearer at 48h in γ-imaging. In controls, the tumor was slightly visualized also to early stage, but faded away later on. Biotin-avidin pretargeting technique can elevate the T/NT ratio and decrease the blood background. Early imaging was obtained with better imaging quality

  5. Currents trends in the application of IBA techniques to air pollution source fingerprinting and source apportionment

    International Nuclear Information System (INIS)

    Cohen, David; Stelcer, Ed.; Atanacio, Armand; Crawford, Jagoda

    2013-01-01

    Full text: IBA techniques have been used for many years to characterise fine particle air pollution. This is not new the techniques are well established. Typically 2-3 MeV protons are used to bombard thin filter papers and up to four simultaneous techniques like PIXE, PIGE, RBS and ERDA will be applied to obtain (μg/g) concentrations for elements from hydrogen to lead. Generally low volume samplers are used to sample between 20-30 m 3 of air over a 24 hour period, this together with IBA's sensitivity means that concentrations down to 1 ng/m 3 of air sampled can be readily achieved with only a few minutes of proton irradiation. With these short irradiation times and low sensitivities for a broad range of elements in the periodic table, large numbers of samples can be obtained and analysed very quickly and easily. At ANSTO we have used IBA methods to acquire a database of over 50,000 filters from 85 different sites through Australia and Asia, each filter has been analysed for more than 21 different chemical species. Large databases extending over many years means that modern statistical techniques like positive matrix factorisation (PMF) can be used to define well characterised source fingerprints and source contributions for a range of different fine particle air pollutants. In this paper we will discuss these PMF techniques and show how they identify both natural sources like sea spray and windblown soils as well as anthropogenic sources like automobiles, biomass burning, coal-fired power stations and industrial emissions. These data are particularly useful for Governments, EPA's and managers of pollution to better understanding pollution sources and their relative contributions and hence to better manage air pollution. Current trends are to take these IBA and PMF techniques a step further and to combine them with wind speed and back trajectory data to better pin point and identify emission sources. We show how this is now being applied on both a local

  6. Currents trends in the application of IBA techniques to air pollution source fingerprinting and source apportionment

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, David; Stelcer, Ed.; Atanacio, Armand; Crawford, Jagoda [Australian Nuclear Science and Technology Organisation, Kirrawee DC (Australia)

    2013-07-01

    Full text: IBA techniques have been used for many years to characterise fine particle air pollution. This is not new the techniques are well established. Typically 2-3 MeV protons are used to bombard thin filter papers and up to four simultaneous techniques like PIXE, PIGE, RBS and ERDA will be applied to obtain (μg/g) concentrations for elements from hydrogen to lead. Generally low volume samplers are used to sample between 20-30 m{sup 3} of air over a 24 hour period, this together with IBA's sensitivity means that concentrations down to 1 ng/m{sup 3} of air sampled can be readily achieved with only a few minutes of proton irradiation. With these short irradiation times and low sensitivities for a broad range of elements in the periodic table, large numbers of samples can be obtained and analysed very quickly and easily. At ANSTO we have used IBA methods to acquire a database of over 50,000 filters from 85 different sites through Australia and Asia, each filter has been analysed for more than 21 different chemical species. Large databases extending over many years means that modern statistical techniques like positive matrix factorisation (PMF) can be used to define well characterised source fingerprints and source contributions for a range of different fine particle air pollutants. In this paper we will discuss these PMF techniques and show how they identify both natural sources like sea spray and windblown soils as well as anthropogenic sources like automobiles, biomass burning, coal-fired power stations and industrial emissions. These data are particularly useful for Governments, EPA's and managers of pollution to better understanding pollution sources and their relative contributions and hence to better manage air pollution. Current trends are to take these IBA and PMF techniques a step further and to combine them with wind speed and back trajectory data to better pin point and identify emission sources. We show how this is now being applied on both

  7. Power Management Based Current Control Technique for Photovoltaic-Battery Assisted Wind-Hydro Hybrid System

    Science.gov (United States)

    Ram Prabhakar, J.; Ragavan, K.

    2013-07-01

    This article proposes new power management based current control strategy for integrated wind-solar-hydro system equipped with battery storage mechanism. In this control technique, an indirect estimation of load current is done, through energy balance model, DC-link voltage control and droop control. This system features simpler energy management strategy and necessitates few power electronic converters, thereby minimizing the cost of the system. The generation-demand (G-D) management diagram is formulated based on the stochastic weather conditions and demand, which would likely moderate the gap between both. The features of management strategy deploying energy balance model include (1) regulating DC-link voltage within specified tolerances, (2) isolated operation without relying on external electric power transmission network, (3) indirect current control of hydro turbine driven induction generator and (4) seamless transition between grid-connected and off-grid operation modes. Furthermore, structuring of the hybrid system with appropriate selection of control variables enables power sharing among each energy conversion systems and battery storage mechanism. By addressing these intricacies, it is viable to regulate the frequency and voltage of the remote network at load end. The performance of the proposed composite scheme is demonstrated through time-domain simulation in MATLAB/Simulink environment.

  8. CANDU fuel sheath integrity and oxide layer thickness determination by Eddy current technique

    International Nuclear Information System (INIS)

    Gheorghe, Gabriela; Man, Ion; Parvan, Marcel; Valeca, Serban

    2010-01-01

    This paper presents results concerning the integrity assessment of the fuel elements cladding and measurements of the oxide layer on sheaths, using the eddy current technique. Flaw detection using eddy current provides information about the integrity of fuel element sheath or presence of defects in the sheath produced by irradiation. The control equipment consists of a flaw detector with eddy currents, operable in the frequency range 10 Hz to 10 MHz, and a differential probe. The calibration of the flaw detector is done using artificial defects (longitudinal, transversal, external and internal notches, bored and unbored holes) obtained on Zircaloy-4 tubes identical to those out of which the sheath of the CANDU fuel element is manufactured (having a diameter of 13.08 mm and a wall thickness of 0.4 mm). When analyzing the behavior of the fuel elements' cladding facing the corrosion is important to know the thickness of the zirconium oxide layer. The calibration of the device measuring the thickness of the oxide layer is done using a Zircaloy-4 tube identical to that which the cladding of the CANDU fuel element is manufactured of, and calibration foils, as well. (authors)

  9. Experimental Issues in Testing a Semiactive Technique to Control Earthquake Induced Vibration

    Directory of Open Access Journals (Sweden)

    Nicola Caterino

    2014-01-01

    Full Text Available This work focuses on the issues to deal with when approaching experimental testing of structures equipped with semiactive control (SA systems. It starts from practical experience authors gained in a recent wide campaign on a large scale steel frame structure provided with a control system based on magnetorheological dampers. The latter are special devices able to achieve a wide range of physical behaviours using low-power electrical currents. Experimental activities involving the use of controllable devices require special attention in solving specific aspects that characterize each of the three phases of the SA control loop: acquisition, processing, and command. Most of them are uncommon to any other type of structural testing. This paper emphasizes the importance of the experimental assessment of SA systems and shows how many problematic issues likely to happen in real applications are also present when testing these systems experimentally. This paper highlights several problematic aspects and illustrates how they can be addressed in order to achieve a more realistic evaluation of the effectiveness of SA control solutions. Undesired and unavoidable effects like delays and control malfunction are also remarked. A discussion on the way to reduce their incidence is also offered.

  10. Experimental determination of liquidus of Fe-Zr by spot technique

    International Nuclear Information System (INIS)

    Ramakrishna, P.; Samanta, B.; Balakrishnan, S.

    2016-01-01

    Metallic fuel alloy for fast reactor mainly consist of U-Pu-Zr housed in T91 clad. Study of thermophysical properties of fuel element and cladding material is vital for the fuel designer to optimize the design feature and predict the fuel behavior under reactor operating conditions.To understand the fuel-clad interaction the phase diagram study of Fe-Zr system is very important since future reactors use U-Pu-Zr alloy as fuel and stainless steel as clad. The eutectic temperature in Fe-Zr alloy system has been established experimentally by various methods. Information on the liquidus temperatures of Fe-Zr is scanty in the literature excepting a very few experimental measurements. Hence measurement of liquidus temperatures is very essential to establish the phase diagram. Present work concentrates more on the generation of liquidus data of Fe-Zr binary alloy system by Spot-technique. This is one among the advanced techniques for measuring the solid-liquid phase transition temperatures. (author)

  11. Understanding the role of fast electrons in the heating of dense matter: experimental techniques and recent results

    International Nuclear Information System (INIS)

    Freeman, R.; Anderson, C.; Hill, J.M.; King, J.; Snavely, R.; Hatchett, S.; Key, M.; Koch, J.; MacKinnon, A.; Stephens, R.; Cowan, T.

    2003-01-01

    An intense laser impinging upon dense matter converts a large fraction of its energy into fast electrons. (Here we take 'fast' to mean electrons that are much more energetic than the normal Boltzmann-like distribution measured in the tens to hundreds of eV.) Upon transiting the interior of the dense matter, these electrons are responsible for isochoric heating of the material. Just how these electrons traverse the material, and various interfaces within the material, is a subject of substantial amounts of computation and theory, and recently, experiments. Here we outline the nature of the heating mechanisms, and the current level of understanding of the complex physical processes. In particular we discuss new experimental techniques to record essential features of this transport problem

  12. An experimental system for coiled tubing partial underbalanced drilling (CT-PUBD) technique

    Science.gov (United States)

    Shi, H. Z.; Ji, Z. S.; Zhao, H. Q.; Chen, Z. L.; Zhang, H. Z.

    2018-05-01

    To improve the rate of penetration (ROP) in hard formations, a new high-speed drilling technique called Coiled Tubing Partial Underbalanced Drilling (CT-PUBD) is proposed. This method uses a rotary packer to realize an underbalanced condition near the bit by creating a micro-annulus and an overbalanced condition at the main part of the annulus. A new full-scale laboratory experimental system is designed and set up to study the hydraulic characteristics and drilling performance of this method. The system is composed of a drilling system, circulation system, and monitor system, including three key devices, namely, cuttings discharge device, rotary packer, and backflow device. The experimental results showed that the pressure loss increased linearly with the flow rate of the drilling fluid. The high drilling speed of CT-PUBD proved it a better drilling method than the conventional drilling. The experimental system may provide a fundamental basis for the research of CT-PUBD, and the results proved that this new method is feasible in enhancing ROP and guaranteeing the drilling safety.

  13. Particular treatments in Eddy current technique. Application to the control of corrugated tubes

    International Nuclear Information System (INIS)

    1982-11-01

    When the testing of a given product shows that, owing to a particular shape of this product or to its environment, disturbing effects can hide the presence of harmful defects, use must be made of testing artifices or particular treatments enabling an efficient examination to be made. On this score, many eddy current problems are solved by means of the following processes: - use of specific sensors adapted to the geometry of the product, - spectral analysis of the analog results of analyses, - combination of the results of analyses obtained simultaneously at different frequencies (multifrequency techniques). An example of an application is given for corrugated tubes achieved by hollow and helical milling of smooth tubes [fr

  14. Current trends in pedicle screw stimulation techniques: lumbosacral, thoracic, and cervical levels.

    Science.gov (United States)

    Isley, Michael R; Zhang, Xiao-Feng; Balzer, Jeffrey R; Leppanen, Ronald E

    2012-06-01

    Unequivocally, pedicle screw instrumentation has evolved as a primary construct for the treatment of both common and complex spinal disorders. However an inevitable and potentially major complication associated with this type of surgery is misplacement of a pedicle screw(s) which may result in neural and vascular complications, as well as impair the biomechanical stability of the spinal instrumentation resulting in loss of fixation. In light of these potential surgical complications, critical reviews of outcome data for treatment of chronic, low-back pain using pedicle screw instrumentation concluded that "pedicle screw fixation improves radiographically demonstrated fusion rates;" however the expense and complication rates for such constructs are considerable in light of the clinical benefit (Resnick et al. 2005a). Currently, neuromonitoring using free-run and evoked (triggered) electromyography (EMG) is widely used and advocated for safer and more accurate placement of pedicle screws during open instrumentation procedures, and more recently, guiding percutaneous placement (minimally invasive) where the pedicle cannot be easily inspected visually. The latter technique, evoked or triggered EMG when applied to pedicle screw instrumentation surgeries, has been referred to as the pedicle screw stimulation technique. As concluded in the Position Statement by the American Society of Neurophysiological Monitoring (ASNM), multimodality neuromonitoring using free-run EMG and the pedicle screw stimulation technique was considered a practice option and not yet a standard of care (Leppanen 2005). Subsequently, the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Joint Section on Disorders of the Spine and Peripheral Nerves published their "Guidelines for the Performance of Fusion Procedures for Degenerative Disease of the Lumbar Spine" (Heary 2005, Resnick et al. 2005a, Resnick et al. 2005b). It was concluded that the "primary

  15. Development techniques and electron optical studies of high voltage, high current electron guns

    International Nuclear Information System (INIS)

    Rangarajan, L.M.; Mahadevan, S.; Ramamurthi, S.S.

    1992-01-01

    The progress of the electron gun design, limiting to axially symmetric geometries is discussed here with a view to utilise such guns for electron accelerators. The mechanical design features leading to the physical configuration of the gun with stringent tolerances are outlined. Vacuum processing is done at pressures of 1.3x10 -5 Pa. The gun employs W-filament emitter or a cathode pellet with bombarder service. A water cooled compact faraday cup is used to measure the electron current. Electron gun geometries have been studied using the computer programme. The preveance of the gun is 0.7x10 -7 A/Vsup(1.5) at 80 kV. Developmental techniques of such pulsed electron guns are described. (author). 7 refs., 5 figs

  16. Current recommendations for the study of carotid stenosis by doppler ultrasound and other imaging techniques

    International Nuclear Information System (INIS)

    Perez Matamoros, Angelica

    2012-01-01

    Ischemic cerebrovascular disease has been one of the most frequent causes of death from chronic disease, as well as cause of long-term disabilities, in both the United States, and in Latin American countries during recent years. It is therefore, important to know about it. An updated review of international recommendations to the Costa Rican health system is performed for carotid imaging study in patients at risk of accidents and ischemic cerebrovascular disease; with special emphasis on carotid Doppler ultrasonography, due to its wide availability in the medical field Costa Rican. Furthermore, certain relevant concepts of other imaging techniques currently available are listed to determine the appropriate choice of each method according to the individual patient's condition, such as conventional angiography and tomographic angiography [es

  17. Input current interharmonics in adjustable speed drives caused by fixed-frequency modulation techniques

    DEFF Research Database (Denmark)

    Soltani, Hamid; Davari, Pooya; Loh, Poh Chiang

    2016-01-01

    Adjustable Speed Drives (ASDs) based on double-stage conversion systems may inject interharmonics distortion into the grid, other than the well-known characteristic harmonic components. The problems created by interharmonics make it necessary to find their precise sources, and, to adopt an approp......Adjustable Speed Drives (ASDs) based on double-stage conversion systems may inject interharmonics distortion into the grid, other than the well-known characteristic harmonic components. The problems created by interharmonics make it necessary to find their precise sources, and, to adopt...... an appropriate strategy for minimizing their effects. This paper investigates the ASD's input current interharmonic sources caused by applying symmetrical regularly sampled fixed-frequency modulation techniques on the inverter. The interharmonics generation process is precisely formulated and comparative results...

  18. Preliminary Experimental Results on the Technique of Artificial River Replenishment to Mitigate Sediment Loss Downstream Dams

    Science.gov (United States)

    Franca, M. J.; Battisacco, E.; Schleiss, A. J.

    2014-12-01

    The transport of sediments by water throughout the river basins, from the steep slopes of the upstream regions to the sea level, is recognizable important to keep the natural conditions of rivers with a role on their ecology processes. Over the last decades, a reduction on the supply of sand and gravel has been observed downstream dams existing in several alpine rivers. Many studies highlight that the presence of a dam strongly modifies the river behavior in the downstream reach, in terms of morphology and hydrodynamics, with consequences on local ecology. Sediment deficit, bed armoring, river incision and bank instability are the main effects which affect negatively the aquatic habitats and the water quality. One of the proposed techniques to solve the problem of sediment deficit downstream dams, already adopted in few Japanese and German rivers although on an unsatisfactory fashion, is the artificial replenishment of these. Generally, it was verified that the erosion of the replenishments was not satisfactory and the transport rate was not enough to move the sediments to sufficient downstream distances. In order to improve and to provide an engineering answer to make this technique more applicable, a series of laboratory tests are ran as preparatory study to understand the hydrodynamics of the river flow when the replenishment technique is applied. Erodible volumes, with different lengths and submergence conditions, reproducing sediment replenishments volumes, are positioned along a channel bank. Different geometrical combinations of erodible sediment volumes are tested as well on the experimental flume. The first results of the experimental research, concerning erosion time evolution, the influence of discharge and the distance travelled by the eroded sediments, will be presented and discussed.

  19. Robot-assisted laparoscopic partial nephrectomy: Current review of the technique and literature

    Directory of Open Access Journals (Sweden)

    Singh Iqbal

    2009-01-01

    Full Text Available Aim: To visit the operative technique and to review the current published English literature on the technique, and outcomes following robot-assisted laparoscopic partial nephrectomy (RPN. Materials and Methods: We searched the published English literature and the PubMed (TM for published series of ′robotic partial nephrectomy′ (RPN using the keywords; robot, robot-assisted laparoscopic partial nephrectomy, laparoscopic partial nephrectomy, partial nephrectomy and laparoscopic surgery. Results: The search yielded 15 major selected series of ′robotic partial nephrectomy′; these were reviewed, tracked and analysed in order to determine the current status and role of RPN in the management of early renal neoplasm(s, as a minimally invasive surgical alternative to open partial nephrectomy. A review of the initial peri-operative outcome of the 350 cases of select series of RPN reported in published English literature revealed a mean operating time, warm ischemia time, estimated blood loss and hospital stay, of 191 minutes, 25 minutes, 162 ml and 2.95 days, respectively. The overall computed mean complication rate of RPN in the present select series was about 7.4%. Conclusions: RPN is a safe, feasible and effective minimally invasive surgical alternative to laparoscopic partial nephrectomy for early stage (T 1 renal neoplasm(s. It has acceptable initial renal functional outcomes without the increased risk of major complications in experienced hands. Prospective randomised, controlled, comparative clinical trials with laparoscopic partial nephrectomy (LPN are the need of the day. While the initial oncological outcomes of RPN appear to be favourable, long-term data is awaited.

  20. Filling of a Salt-withdrawal Minibasin on the Continental Slope by Turbidity Currents: Experimental study

    Science.gov (United States)

    Violet, J.; Evans, C.; Sheets, B.; Paola, C.; Pratson, L.; Parker, G.

    2001-12-01

    We report on the transport and deposition of sediment by turbidity currents in an experimental basin designed to model salt-withdrawal minibasins found along the northern continental slope of the Gulf of Mexico. The experiment was performed in two stages in the subsiding EXperimental EarthScape facility (XES) at St. Anthony Falls Laboratory, University of Minnesota. Stage I consisted of 15 turbidity-current events in the following sequence: one 36-minute continuous event, six 1.85-minute small pulses, one 3.8-minute large pulse, six more small pulses, one more large pulse, and finally one more continuous event. The continuous events and the small pulses had a flow discharge of 1.5 liters/s and the large pulse had a flow discharge of 4.5 liters/s. The flows all had a volume concentration of sediment of 0.05. The sediment comprised three grades of silica with nominal diameters of 20 microns (45%), 45 microns (40%) and 110 microns (15%). The basin subsided continuously during Stage I. Stage II consisted of the same sequence of events as Stage I, but with no further subsidence. The sand content was eliminated during the latter part of Stage II. The deposit was imaged as it developed during the experiment using high-frequency sonar. The sonar records show indications of incipient self-channelization as well as clear erosion, bypass, and deposition. Erosion was promoted by large pulse events and the absence of sand. The deposit shows well developed lamination and normal grading.

  1. Imaging techniques in the management of chronic kidney disease: current developments and future perspectives.

    Science.gov (United States)

    Herget-Rosenthal, Stefan

    2011-05-01

    The measurement of both renal function and structure is critical in clinical nephrology to detect, stage, and monitor chronic kidney disease (CKD). Current imaging modalities especially ultrasound (US), computed tomography, and magnetic resonance imaging (MRI) provide adequate information on structural changes but little on functional impairment in CKD. Although not yet considered first-line procedures for evaluating patients with renal disease, new US and MR imaging techniques may permit the assessment of renal function in the near future. Combined with established imaging techniques, contrast-enhanced US, dynamic contrast-enhanced MRI, blood oxygen level dependency MRI, or diffusion-weighted imaging may provide rapid, accurate, simultaneous, and noninvasive imaging of the structure of kidneys, macrovascular and microvascular renal perfusion, oxygenation, and glomerular filtration rate. Recent developments in molecular imaging indicate that pathophysiological pathways of renal diseases such as apoptosis, coagulation, fibrosis, and ischemia will be visualized at the tissue level. These major advances in imaging and developments in hardware and software could enable comprehensive imaging of renal structure and function in four dimensions (three dimensions plus time), and imaging is expected to play an increasing role in the management of CKD. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. New tools, technology and techniques applied in geological sciences: current situation and future perspectives

    International Nuclear Information System (INIS)

    Ulloa, Andres

    2014-01-01

    Technological tools and work methodologies most used in the area of geological sciences are reviewed and described. The various electronic devices such as laptops, palmtops or PDA (personal digital assistant), tablets and smartphones have allowed to take field geological data and store them efficiently. Tablets and smartphones have been convenient for data collection of scientific data by the diversity of sensors that present, portability, autonomy and the possibility to install specific applications. High precision GPS in conjunction with LIDAR technology and sonar technology have been more accessible and used for geological research, generating high resolution three-dimensional models to complement geological studies. Remote sensing techniques such as high penetration radar are used to perform models of the ice thickness and topography in Antarctic. Modern three-dimensional scanning and printing techniques are used in geological science research and teaching. Currently, the advance in the computer technology has allowed to handle three-dimensional models on personal computers efficiently way and with different display options. Some, of the new areas of geology, emerged recently, are mentioned to generate a broad panorama toward where can direct geological researches in the next years [es

  3. A Smoothing Technique for the Multifractal Analysis of a Medium Voltage Feeders Electric Current

    Science.gov (United States)

    de Santis, Enrico; Sadeghian, Alireza; Rizzi, Antonello

    2017-12-01

    The current paper presents a data-driven detrending technique allowing to smooth complex sinusoidal trends from a real-world electric load time series before applying the Detrended Multifractal Fluctuation Analysis (MFDFA). The algorithm we call Smoothed Sort and Cut Fourier Detrending (SSC-FD) is based on a suitable smoothing of high power periodicities operating directly in the Fourier spectrum through a polynomial fitting technique of the DFT. The main aim consists of disambiguating the characteristic slow varying periodicities, that can impair the MFDFA analysis, from the residual signal in order to study its correlation properties. The algorithm performances are evaluated on a simple benchmark test consisting of a persistent series where the Hurst exponent is known, with superimposed ten sinusoidal harmonics. Moreover, the behavior of the algorithm parameters is assessed computing the MFDFA on the well-known sunspot data, whose correlation characteristics are reported in literature. In both cases, the SSC-FD method eliminates the apparent crossover induced by the synthetic and natural periodicities. Results are compared with some existing detrending methods within the MFDFA paradigm. Finally, a study of the multifractal characteristics of the electric load time series detrendended by the SSC-FD algorithm is provided, showing a strong persistent behavior and an appreciable amplitude of the multifractal spectrum that allows to conclude that the series at hand has multifractal characteristics.

  4. Laparoscopic Pediatric Inguinal Hernia Repair: Overview of "True Herniotomy" Technique and Review of Current Evidence.

    Science.gov (United States)

    Feehan, Brendan P; Fromm, David S

    2017-05-01

    Inguinal hernia repair is one of the most commonly performed operations in the pediatric population. While the majority of pediatric surgeons routinely use laparoscopy in their practices, a relatively small number prefer a laparoscopic inguinal hernia repair over the traditional open repair. This article provides an overview of the three port laparoscopic technique for inguinal hernia repair, as well as a review of the current evidence with respect to visualization and identification of hernias, recurrence rates, operative times, complication rates, postoperative pain, and cosmesis. The laparoscopic repair presents a viable alternative to open repair and offers a number of benefits over the traditional approach. These include superior visualization of the relevant anatomy, ability to assess and repair a contralateral hernia, lower rates of metachronous hernia, shorter operative times in bilateral hernia, and the potential for lower complication rates and improved cosmesis. This is accomplished without increasing recurrence rates or postoperative pain. Further research comparing the different approaches, including standardization of techniques and large randomized controlled trials, will be needed to definitively determine which is superior. Copyright© South Dakota State Medical Association.

  5. Additive Manufacturing Techniques in Prosthodontics: Where Do We Currently Stand? A Critical Review.

    Science.gov (United States)

    Alharbi, Nawal; Wismeijer, Daniel; Osman, Reham B

    The aim of this article was to critically review the current application of additive manufacturing (AM)/3D-printing techniques in prosthodontics and to highlight the influence of various technical factors involved in different AM technologies. A standard approach of searching MEDLINE, EMBASE, and Google Scholar databases was followed. The following search terms were used: (Prosth* OR Restoration) AND (Prototype OR Additive Manufacture* OR Compute* OR 3D-print* OR CAD/CAM) AND (Dentistry OR Dental). Hand searching the reference lists of the included articles and personal connections revealed additional relevant articles. Selection criteria were any article written in English and reporting on the application of AM in prosthodontics from 1990 to February 2016. From a total of 4,290 articles identified, 33 were seen as relevant. Of these, 3 were narrative reviews, 18 were in vitro studies, and 12 were clinical in vivo studies. Different AM technologies are applied in prosthodontics, directly and indirectly for the fabrication of fixed metal copings, metal frameworks for removable partial dentures, and plastic mock-ups and resin patterns for further conventional metal castings. Technical factors involved in different AM techniques influence the overall quality, the mechanical properties of the printed parts, and the total cost and manufacturing time. AM is promising and offers new possibilities in the field of prosthodontics, though its application is still limited. An understanding of these limitations and of developments in material science is crucial prior to considering AM as an acceptable method for the fabrication of dental prostheses.

  6. Current surgical practices in cleft care: cleft palate repair techniques and postoperative care.

    Science.gov (United States)

    Katzel, Evan B; Basile, Patrick; Koltz, Peter F; Marcus, Jeffrey R; Girotto, John A

    2009-09-01

    The purpose of this study was to objectively report practices commonly used in cleft palate repair in the United States. This study investigates current surgical techniques, postoperative care, and complication rates for cleft palate repair surgery. All 803 surgeon members of the American Cleft Palate-Craniofacial Association were sent online and/or paper surveys inquiring about their management of cleft palate patients. Three-hundred six surveys were received, a 38 percent response rate. This represented responses of surgeons from 100 percent of American Cleft Palate-Craniofacial Association registered cleft teams. Ninety-six percent of respondents perform a one-stage repair. Eighty-five percent of surgeons perform palate surgery when the patient is between 6 and 12 months of age. The most common one-stage repair techniques are the Bardach style (two flaps) with intravelar veloplasty and the Furlow palatoplasty. After surgery, 39 percent of surgeons discharge patients within 24 hours. Another 43 percent discharge patients within 48 hours. During postoperative management, 92 percent of respondents implement feeding restrictions. Eighty-five percent of physicians use arm restraints. Surgeons' self-reported complications rates are minimal: 54 percent report a fistula in less than 5 percent of cases. The reported need for secondary speech surgery varies widely. The majority of respondents repair clefts in one stage. The most frequently used repair techniques are the Furlow palatoplasty and the Bardach style with intravelar veloplasty. After surgery, the majority of surgeons discharge patients in 1 or 2 days, and nearly all surgeons implement feeding restrictions and the use of arm restraints. The varying feeding protocols are reviewed in this article.

  7. Comparison radiation dose of Z-axis automatic tube current modulation technique with fixed tube current multi-detector row CT scanning of lower extremity venography

    International Nuclear Information System (INIS)

    Yoo, Beong Gyu; Kweon, Dae Cheol; Lee, Jong Seok; Jang, Keun Jo; Jeon, Sang Hwan; Kim, Yong Soo

    2007-01-01

    Z-axis automatic tube current modulation technique automatically adjusts tube current based on size of body region scanned. The purpose of the current study was to compare noise, and radiation dose of Multi-Detector row CT (MDCT) of lower extremity performed with Z-axis modulation technique of automatic tube current modulation with manual selection fixed tube current. Fifty consecutive underwent MDCT venography of lower extremity with use of a MDCT scanner fixed tube current and Z-axis automatic tube current modulation technique (10, 11 and 12 HU noise index, 70∼450 mA). Scanning parameters included 120 kVp, 0.5 second gantry rotation time, 1.35:1 beam pitch, and 1 mm reconstructed section thickness. For each subject, images obtained with Z-axis modulation were compared with previous images obtained with fixed tube current (200, 250, 300 mA) and with other parameters identical. Images were compared for noise at five levels: iliac, femoral, popliteal, tibial, and peroneal vein of lower extremity. Tube current and gantry rotation time used for acquisitions at these levels were recorded. All CT examinations of study and control groups were diagnostically acceptable, though objective noise was significantly more with Z-axis automatic tube current modulation. Compared with fixed tube current, Z-axis modulation resulted in reduction of CTDIvol (range, -6.5%∼-35.6%) and DLP (range,-0.2%∼-20.2%). Compared with manually selected fixed tube current, Z-axis automatic tube current modulation resulted in reduced radiation dose at MDCT of lower extremity venography

  8. AN EXPERIMENTAL STUDY OF THE EFFICACY AND SAFETY OF VARIOUS ENDOSCOPIC HEMOSTASIS TECHNIQUES

    Directory of Open Access Journals (Sweden)

    A. I. Cherepanin

    2014-01-01

    Full Text Available ABSTRACT. The treatment of bleeding peptic ulcers remains one of the pressing challenges in urgent surgery. Currently available endoscopic hemostasis modalities only partially meet the requirements of safety, efficiency and reliability, and therefore total and postoperative mortality rates are still high, both in our country, and around the world. The aim of the study was to identify the benefits and shortcomings of endoscopic radiofrequency energy exposure compared to standard hemostatic techniques used in the world practice to treat bleeding peptic ulcers. 

  9. Fed-state gastric media and drug analysis techniques: Current status and points to consider.

    Science.gov (United States)

    Baxevanis, Fotios; Kuiper, Jesse; Fotaki, Nikoletta

    2016-10-01

    Gastric fed state conditions can have a significant effect on drug dissolution and absorption. In vitro dissolution tests with simple aqueous media cannot usually predict drugs' in vivo response, as several factors such as the meal content, the gastric emptying and possible interactions between food and drug formulations can affect drug's pharmacokinetics. Good understanding of the effect of the in vivo fed gastric conditions on the drug is essential for the development of biorelevant dissolution media simulating the gastric environment after the administration of the standard high fat meal proposed by the FDA and the EMA in bioavailability/bioequivalence (BA/BE) studies. The analysis of drugs in fed state media can be quite challenging as most analytical protocols currently employed are time consuming and labour intensive. In this review, an overview of the in vivo gastric conditions and the biorelevant media used for their in vitro simulation are described. Furthermore an analysis of the physicochemical properties of the drugs and the formulations related to food effect is given. In terms of drug analysis, the protocols currently used for the fed state media sample treatment and analysis and the analytical challenges and needs emerging for more efficient and time saving techniques for a broad spectrum of compounds are being discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Robot-assisted pyeloplasty: review of the current literature, technique and outcome.

    Science.gov (United States)

    Singh, Iqbal; Hemal, Ashok K

    2010-04-01

    To review the global select data on the current technique, perioperative outcome and literature on the robot-assisted pyeloplasty (RAP). The published English literature (PubMed) was extensively searched using the key words; robot, robot-assisted pyeloplasty, laparoscopy, laparoscopic pyeloplasty and ureteropelvic junction obstruction. The selected studies were then reviewed, tracked and analyzed in order to determine the current role, outcome and status of robot-assisted laparoscopic pyeloplasty. The search yielded about 25 published series on RAP comprising about 740 cases with a mean operative time, estimated blood loss, crossing vessel prevalence, hospital stay,perioperative complication rate and follow up duration of 194 min, 50 mL, 47%, 2.3 days, 6% and 14.9 months respectively. The initial peri-operative results and intermediate follow up of cases of repair of the ureteropelvic junction obstruction with robot-assisted pyeloplasty appear to be favorable and comparable to that of open pyeloplasty, while long term outcome data is still awaited. The da Vinci surgical robotic system is a promising surgical armamentarium in the hands of the modern day urologist for the minimally invasive definitive surgical management of both primary and secondary ureteropelvic junction obstruction.

  11. SEM technique for experimentally locating latch-up paths in integrated circuits

    International Nuclear Information System (INIS)

    Dressendorfer, P.V.; Armendariz, M.G.

    1980-01-01

    A technique is presented for using the scanning electron microscope (SEM) in the electron-beam-induced current (EBIC) mode to delineate latch-up paths in CMOS ICs. In the EBIC mode, the current produced by the collection and separation of the electron-beam-generated electron-hole pairs in the space charge regions of the device is measured and used to form an image. Since the collection of these carriers is dependent on space charge region width (and thus junction potential), anything that alters the depletion layer width will affect the collection efficiency. In a latch condition the junctions involved in the latch will be biased differently from those which are not, and thus the EBIC signal from those regions should be measurably different

  12. Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones

    International Nuclear Information System (INIS)

    Gosselin, Marie-Christine; Kühn, Sven; Kuster, Niels

    2013-01-01

    The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., −16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system. (paper)

  13. Experimental study of falling water limitation under counter-current flow in the vertical rectangular channel

    International Nuclear Information System (INIS)

    Usui, Tohru; Kaminaga, Masanori; Sudo, Yukio.

    1988-07-01

    Quantitative understanding of critical heat flux (CHF) in the narrow vertical rectangular channel is required for the thermo-hydroulic design and the safety analysis of research reactors in which flat-plate-type fuel is adopted. Especially, critical heat flux under low downward velocity has a close relation with falling water limitation under counter-current flow. Accordingly, CCFL (Counter-current Flow Limitation) experiments were carried out for both vertical rectangular channels and vertical circular tubes varried in their size and configuration of their cross sections, to make clear CCFL characteristics in the vertical rectangular channels. In the experiments, l/de of the rectangular channel was changed from 3.5 to 180. As the results, it was clear that different equivalent hydraulic diameter de, namely width or water gap of channel, gave different CCFL characteristics of rectangular channel. But the influence of channel length l on CCFL characteristics was not observed. Besides, a dimensionless correlation to estimate a relation between upward air velocity and downward water velocity was proposed based on the present experimental results. The difference of CCFL characteristics between rectangular channels and circular tubes was also investigated. Especially for the rectangular channels, dry-patches appearing condition was made clear as a flow-map. (author)

  14. Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones

    Science.gov (United States)

    Gosselin, Marie-Christine; Kühn, Sven; Kuster, Niels

    2013-12-01

    The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., -16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system.

  15. Current calibration, treatment, and treatment planning techniques among institutions participating in the Children's Oncology Group

    International Nuclear Information System (INIS)

    Urie, Marcia; FitzGerald, T.J.; Followill, David; Laurie, Fran; Marcus, Robert; Michalski, Jeff

    2003-01-01

    Purpose: To report current technology implementation, radiation therapy physics and treatment planning practices, and results of treatment planning exercises among 261 institutions belonging to the Children's Oncology Group (COG). Methods and Materials: The Radiation Therapy Committee of the newly formed COG mandated that each institution demonstrate basic physics and treatment planning abilities by satisfactorily completing a questionnaire and four treatment planning exercises designed by the Quality Assurance Review Center. The planning cases are (1) a maxillary sinus target volume (for two-dimensional planning), (2) a Hodgkin's disease mantle field (for irregular-field and off-axis dose calculations), (3) a central axis blocked case, and (4) a craniospinal irradiation case. The questionnaire and treatment plans were submitted (as of 1/30/02) by 243 institutions and completed satisfactorily by 233. Data from this questionnaire and analyses of the treatment plans with monitor unit calculations are presented. Results: Of the 243 clinics responding, 54% use multileaf collimators routinely, 94% use asymmetric jaws routinely, and 13% use dynamic wedges. Nearly all institutions calibrate their linear accelerators following American Association of Physicists in Medicine protocols, currently 16% with TG-51 and 81% with TG-21 protocol. Treatment planning systems are relied on very heavily for all calculations, including monitor units. Techniques and results of each of the treatment planning exercises are presented. Conclusions: Together, these data provide a unique compilation of current (2001) radiation therapy practices in institutions treating pediatric patients. Overall, the COG facilities have the equipment and the personnel to perform high-quality radiation therapy. With ongoing quality assurance review, radiation therapy compliance with COG protocols should be high

  16. The fate of neurotization techniques on reinnervation after denervation of the gastrocnemius muscle: an experimental study.

    Science.gov (United States)

    Askar, I; Sabuncuoglu, B T; Yormuk, E; Saray, A

    2001-07-01

    In nerve injuries, if it is not possible to reinnervate muscle by using neurorrhaphy and nerve grafting technique, reinnervation should be provided by the use of neuroization-directly implanting motor nerve into muscle. A comparative study of three techniques of neurotization is presented in rabbits. In this experimental study, a total of 40 white New Zealand rabbits were used and divided into four groups, each including 10 rabbits. In the first group (control--Group 1), only surgical exposure of the gastrocnemius muscle, main muscle nerve (tibial nerve), and peroneal nerve was done, without any injury to the nerves. In the second group (direct neurotization group--Group 2), the tibial nerve was transected, and the peroneal nerve, which had already been divided into fascicles, was implanted into the lateral head of the gastrocnemius muscle aneural zone. In the third group (dual neurotization group--Group 3), the tibial nerve which had been transected and re-anastomosed, and the peroneal nerve were implanted into the lateral head of the gastrocnemius muscle. In the last experimental group (hyperneurotization group--Group 4), fascicles of the peroneal nerve were implanted into the lateral head of the gastrocnemius, preserving the tibial nerve. Six months later, changes in the histologic pattern and the functional recovery of the gastrocnemius muscle were investigated. It was found that functional recovery was achieved in all neurotization groups. Groups with the tibial nerve transected had less muscular weights than those of groups with the tibial nerve intact. EMG recordings showed that polyphasic and late potentials were frequently seen in groups with the tibial nerve transected. Degeneration and regeneration of myofibrils was observed in such groups as well. New motor end-plates, including vesicles, were formed in a scattered manner in all neurotization groups. As a result, the authors conclude that direct and dual neurotization techniques are useful in peripheral

  17. Comparison of experimental and theoretical reaction rail currents, rail voltages, and airgap fields for the linear induction motor research vehicle

    Science.gov (United States)

    Elliott, D. G.

    1977-01-01

    Measurements of reaction rail currents, reaction rail voltages, and airgap magnetic fields in tests of the Linear Induction Motor Research Vehicle (LIMRV) were compared with theoretical calculations from the mesh/matrix theory. It was found that the rail currents and magnetic fields predicted by the theory are within 20 percent of the measured currents and fields at most motor locations in most of the runs, but differ by as much as a factor of two in some cases. The most consistent difference is a higher experimental than theoretical magnetic field near the entrance of the motor and a lower experimental than theoretical magnetic field near the exit. The observed differences between the theoretical and experimental magnetic fields and currents do not account for the differences of as much as 26 percent between the theoretical and experimental thrusts.

  18. Experimental observation of silver and gold penetration into dental ceramic by means of a radiotracer technique

    International Nuclear Information System (INIS)

    Moya, F.; Payan, J.; Bernardini, J.; Moya, E.G.

    1987-01-01

    A radiotracer technique was used to study silver and gold diffusion into dental porcelain under experimental conditions close to the real conditions in prosthetic laboratories for porcelain bakes. It was clearly shown that these non-oxidizable elements were able to diffuse into the ceramic as well as oxidizable ones. The penetration depth varied widely according to the element. The ratio DAg/DAu was about 10(3) around 850 degrees C. In contrast to gold, the silver diffusion rate was high enough to allow silver, from the metallic alloy, to be present at the external ceramic surface after diffusion into the ceramic. Hence, the greening of dental porcelains baked on silver-rich alloys could be explained mainly by a solid-state diffusion mechanism

  19. Evaluation of CFD Turbulent Heating Prediction Techniques and Comparison With Hypersonic Experimental Data

    Science.gov (United States)

    Dilley, Arthur D.; McClinton, Charles R. (Technical Monitor)

    2001-01-01

    Results from a study to assess the accuracy of turbulent heating and skin friction prediction techniques for hypersonic applications are presented. The study uses the original and a modified Baldwin-Lomax turbulence model with a space marching code. Grid converged turbulent predictions using the wall damping formulation (original model) and local damping formulation (modified model) are compared with experimental data for several flat plates. The wall damping and local damping results are similar for hot wall conditions, but differ significantly for cold walls, i.e., T(sub w) / T(sub t) hypersonic vehicles. Based on the results of this study, it is recommended that the local damping formulation be used with the Baldwin-Lomax and Cebeci-Smith turbulence models in design and analysis of Hyper-X and future hypersonic vehicles.

  20. Development of Experimental Setup of Metal Rapid Prototyping Machine using Selective Laser Sintering Technique

    Science.gov (United States)

    Patil, S. N.; Mulay, A. V.; Ahuja, B. B.

    2018-04-01

    Unlike in the traditional manufacturing processes, additive manufacturing as rapid prototyping, allows designers to produce parts that were previously considered too complex to make economically. The shift is taking place from plastic prototype to fully functional metallic parts by direct deposition of metallic powders as produced parts can be directly used for desired purpose. This work is directed towards the development of experimental setup of metal rapid prototyping machine using selective laser sintering and studies the various parameters, which plays important role in the metal rapid prototyping using SLS technique. The machine structure in mainly divided into three main categories namely, (1) Z-movement of bed and table, (2) X-Y movement arrangement for LASER movements and (3) feeder mechanism. Z-movement of bed is controlled by using lead screw, bevel gear pair and stepper motor, which will maintain the accuracy of layer thickness. X-Y movements are controlled using timing belt and stepper motors for precise movements of LASER source. Feeder mechanism is then developed to control uniformity of layer thickness metal powder. Simultaneously, the study is carried out for selection of material. Various types of metal powders can be used for metal RP as Single metal powder, mixture of two metals powder, and combination of metal and polymer powder. Conclusion leads to use of mixture of two metals powder to minimize the problems such as, balling effect and porosity. Developed System can be validated by conducting various experiments on manufactured part to check mechanical and metallurgical properties. After studying the results of these experiments, various process parameters as LASER properties (as power, speed etc.), and material properties (as grain size and structure etc.) will be optimized. This work is mainly focused on the design and development of cost effective experimental setup of metal rapid prototyping using SLS technique which will gives the feel of

  1. Current updates on laboratory techniques for the diagnosis of male reproductive failure

    Directory of Open Access Journals (Sweden)

    Suresh C Sikka

    2016-01-01

    Full Text Available The incidence of male reproductive failure leading to infertility, whether due to delayed parenthood, environmental issues, genetic factors, drugs, etc., is increasing throughout the world. The diagnosis and prognosis of male subfertility have become a challenge. While the basic semen assessment has been performed for many years, a number of studies question the value of the traditional semen characteristics. This is partly due to inadequate methods and standardization, limited knowledge of technical requirements for quality assurance, and an incomplete understanding of what clinical information a semen assessment can provide. Laboratories currently performing semen and endocrine assessment show great variability. The World Health Organization (WHO manual for the evaluation of semen has been the core of andrology and fertility evaluation that has helped in further development of this field over many years. These include the physical appearance of the ejaculate, assessments of sperm count, motility, vitality, morphology, and functional aspects of the sperm and semen sample. These tests also include male endocrine profile, biochemical evaluation of the semen, detection of antisperm antibodies in serum, the use of computer-aided sperm analysis (CASA, sperm DNA integrity, and its damage due to oxidative stress. Assisted reproductive techniques (e.g., IVF, ICSI have shown great success but are too expensive. Further development in this field with newer techniques and extensive training/instructions can improve accuracy and reduce variability, thus maintaining the quality and standards of such an evaluation. There is an urgent need to have standardized training centers and increased awareness in this area of men′s health for reproductive success.

  2. Laparoscopic major hepatectomies: current trends and indications. A comparison with the open technique.

    Science.gov (United States)

    Ratti, Francesca; Cipriani, Federica; Ariotti, Riccardo; Giannone, Fabio; Paganelli, Michele; Aldrighetti, Luca

    2015-06-01

    Diffusion of laparoscopic major hepatectomies is experiencing a steady increasing trend, although slower compared to minor resections. The aim of this single-center study is to discuss current trends and indications in the application of minimally invasive techniques to major hepatic resections. Preoperative patients and disease characteristics of 49 laparoscopic major hepatectomies (LPS group), performed between 2005 and 2015, were compared with 585 open hepatectomies (Open group) to analyze differences in patients recruitment. Factors which were found to be differently distributed between groups were used as covariates in a propensity score-based case-matched analysis with a 1:3 ratio between LPS group and 147 patients from the Open group (constituting Open-mat group). Short-term outcome was analyzed in matched groups. ASA score, previous abdominal surgery, previous interventional procedures, indication, lesion size and associated procedures were significantly different between the LPS and the Open group. Short-term outcome analysis revealed that blood loss (200 vs 350 mL, p = 0.044) and time for functional recovery (3 vs 4 days, p = 0.05) were reduced in the LPS compared to the Open-mat group, in spite of longer length of surgery (260 vs 170 min, p = 0.041) and comparable oncological adequacy. Even though data on technical feasibility of laparoscopic major resections and their benefits in terms of blood loss and functional recovery support the diffusion of minimally invasive approach, the limit of the technique is still represented by the reduced pool of suitable candidates.

  3. Current knowledge and importance of dGEMRIC techniques in diagnosis of hip joint diseases

    Energy Technology Data Exchange (ETDEWEB)

    Zilkens, Christoph; Krauspe, Ruediger; Bittersohl, Bernd [University of Duesseldorf, Medical Faculty, Department of Orthopedic Surgery, Duesseldorf (Germany); Tiderius, Carl Johann [Lund University Hospital, Department of Orthopedic Surgery, Lund (Sweden)

    2015-08-15

    Accurate assessment of early hip joint cartilage alterations may help optimize patient selection and follow-up of hip joint preservation surgery. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is sensitive to the glycosaminoglycan content in cartilage that is lost early in the development of osteoarthritis (OA). Hence, the dGEMRIC technique holds promise for the development of new diagnostic and therapeutic procedures. However, because of the location of the hip joint deep within the body and due to the fairly thin cartilage layers that require high spatial resolution, the diagnosis of early hip joint cartilage alterations may be problematic. The purpose of this review is to outline the current status of dGEMRIC in the assessment of hip joint cartilage. A literature search was performed with PubMed, using the terms ''cartilage, osteoarthritis, hip joint, MRI, and dGEMRIC'', considering all levels of studies. This review revealed that dGEMRIC can be reliably used in the evaluation of early stage cartilage pathology in various hip joint disorders. Modifications in the technique, such as the operation of three-dimensional imaging and dGEMRIC after intra-articular contrast medium administration, have expanded the range of application. Notably, the studies differ considerably in patient selection and technical prerequisites. Furthermore, there is a need for multicenter prospective studies with the required technical conditions in place to establish outcome based dGEMRIC data to obtain, in conjunction with clinical data, reliable threshold values for normal and abnormal cartilage, and for hips that may benefit from conservative or surgical treatment. (orig.)

  4. Current knowledge and importance of dGEMRIC techniques in diagnosis of hip joint diseases

    International Nuclear Information System (INIS)

    Zilkens, Christoph; Krauspe, Ruediger; Bittersohl, Bernd; Tiderius, Carl Johann

    2015-01-01

    Accurate assessment of early hip joint cartilage alterations may help optimize patient selection and follow-up of hip joint preservation surgery. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is sensitive to the glycosaminoglycan content in cartilage that is lost early in the development of osteoarthritis (OA). Hence, the dGEMRIC technique holds promise for the development of new diagnostic and therapeutic procedures. However, because of the location of the hip joint deep within the body and due to the fairly thin cartilage layers that require high spatial resolution, the diagnosis of early hip joint cartilage alterations may be problematic. The purpose of this review is to outline the current status of dGEMRIC in the assessment of hip joint cartilage. A literature search was performed with PubMed, using the terms ''cartilage, osteoarthritis, hip joint, MRI, and dGEMRIC'', considering all levels of studies. This review revealed that dGEMRIC can be reliably used in the evaluation of early stage cartilage pathology in various hip joint disorders. Modifications in the technique, such as the operation of three-dimensional imaging and dGEMRIC after intra-articular contrast medium administration, have expanded the range of application. Notably, the studies differ considerably in patient selection and technical prerequisites. Furthermore, there is a need for multicenter prospective studies with the required technical conditions in place to establish outcome based dGEMRIC data to obtain, in conjunction with clinical data, reliable threshold values for normal and abnormal cartilage, and for hips that may benefit from conservative or surgical treatment. (orig.)

  5. An experimental technique for the direct measurement of N2O5 reactivity on ambient particles

    Directory of Open Access Journals (Sweden)

    T. H. Bertram

    2009-06-01

    Full Text Available An experimental approach for the direct measurement of trace gas reactivity on ambient aerosol particles has been developed. The method utilizes a newly designed entrained aerosol flow reactor coupled to a custom-built chemical ionization mass spectrometer. The experimental method is described via application to the measurement of the N2O5 reaction probability, γ (N2O5. Laboratory investigations on well characterized aerosol particles show that measurements of γ (N2O5 observed with this technique are in agreement with previous observations, using conventional flow tube methods, to within ±20% at atmospherically relevant particle surface area concentrations (0–1000 μm2 cm−3. Uncertainty in the measured γ (N2O5 is discussed in the context of fluctuations in potential ambient biases (e.g., temperature, relative humidity and trace gas loadings. Under ambient operating conditions we estimate a single-point uncertainty in γ (N2O5 that ranges between ± (1.3×10-2 + 0.2×γ (N2O5, and ± (1.3×10-3 + 0.2×γ (N2O5 for particle surface area concentrations of 100 to 1000 μm2 cm−3, respectively. Examples from both laboratory investigations and field observations are included alongside discussion of future applications for the reactivity measurement and optimal deployment locations and conditions.

  6. Applications of energy-release-rate techniques to part-through cracks in experimental pressure vessels

    International Nuclear Information System (INIS)

    Bass, B.R.; Bryan, R.H.; Bryson, J.W.; Merkle, J.G.

    1982-01-01

    In nonlinear applications of computational fracture mechanics, energy release rate techniques are used increasingly for computing stress intensity parameters of crack configurations. Recently, deLorenzi used the virtual-crack-extension method to derive an analytical expression for the energy release rate that is better suited for three-dimensional calculations than the well-known J-integral. Certain studies of fracture phenomena, such as pressurized-thermal-shock of cracked structures, require that crack tip parameters be determined for combined thermal and mechanical loads. A method is proposed here that modifies the isothermal formulation of deLorenzi to account for thermal strains in cracked bodies. This combined thermo-mechanical formulation of the energy release rate is valid for general fracture, including nonplanar fracture, and applies to thermo-elastic as well as deformation plasticity material models. Two applications of the technique are described here. In the first, semi-elliptical surface cracks in an experimental test vessel are analyzed under elastic-plastic conditions using the finite element method. The second application is a thick-walled test vessel subjected to combined pressure and thermal shock loadings

  7. Aerosols from metal cutting techniques typical of decommissioning nuclear facilities - experimental system for collection and characterization

    International Nuclear Information System (INIS)

    Newton, G.J.; Hoover, M.D.; Barr, E.B.; Wong, B.A.; Ritter, P.D.

    1982-01-01

    Decommissioning of radioactively contaminated sites has the potential for creating radioactive and other potentially toxic aerosols. We describe an experimental system to collect and characterize aerosols from metal cutting activities typical of those used in decommissioning of nuclear facilities. A special enclosure was designed for the experiment and consisted of a 2-in. x 4-in. stud frame with double walls of flame retardant polyethylene film. Large plexiglass windows allowed the cutting operations to be directed and filmed. Ventilation was 8500 L/min (300 CFM) exhausted through HEPA filters. Seven cutting techniques were evaluated: pipe cutter, reciprocating saw, band saw, chop saw, oxy-acetylene torch, electric arc cut rod and plasma torch. Two grinding tools were also evaluated. Materials cut were 2-, 3- and 4-in. dia schedule 40, 80 and 180 type 304L stainless steel pipe. Basic studies were done on uncontaminated pipe. Four-inch-diameter sections of schedule 180 type 304L stainless steel pipe with radioactively contaminated internal surfaces were also cut. The experiments controlled important variables including tools, cutting technique, and type and thickness of material. 15 references, 4 figures, 2 tables

  8. Discrimination of Inrush from Fault Currents in Power Transformers Based on Equivalent Instantaneous Inductance Technique Coupled with Finite Element Method

    Directory of Open Access Journals (Sweden)

    M. Jamali

    2011-09-01

    Full Text Available The phenomenon of magnetizing inrush is a transient condition, which occurs primarily when a transformer is energized. The magnitude of inrush current may be as high as ten times or more times of transformer rated current that causes malfunction of protection system. So, for safe running of a transformer, it is necessary to distinguish inrush current from fault currents. In this paper, an equivalent instantaneous inductance (EII technique is used to discriminate inrush current from fault currents. For this purpose, a three-phase power transformer has been simulated in Maxwell software that is based on finite elements. This three-phase power transformer has been used to simulate different conditions. Then, the results have been used as inputs in MATLAB program to implement the equivalent instantaneous inductance technique. The results show that in the case of inrush current, the equivalent instantaneous inductance has a drastic variation, while it is almost constant in the cases of fault conditions.

  9. Refractive error assessment: influence of different optical elements and current limits of biometric techniques.

    Science.gov (United States)

    Ribeiro, Filomena; Castanheira-Dinis, Antonio; Dias, Joao Mendanha

    2013-03-01

    To identify and quantify sources of error on refractive assessment using exact ray tracing. The Liou-Brennan eye model was used as a starting point and its parameters were varied individually within a physiological range. The contribution of each parameter to refractive error was assessed using linear regression curve fits and Gaussian error propagation analysis. A MonteCarlo analysis quantified the limits of refractive assessment given by current biometric measurements. Vitreous and aqueous refractive indices are the elements that influence refractive error the most, with a 1% change of each parameter contributing to a refractive error variation of +1.60 and -1.30 diopters (D), respectively. In the phakic eye, axial length measurements taken by ultrasound (vitreous chamber depth, lens thickness, and anterior chamber depth [ACD]) were the most sensitive to biometric errors, with a contribution to the refractive error of 62.7%, 14.2%, and 10.7%, respectively. In the pseudophakic eye, vitreous chamber depth showed the highest contribution at 53.7%, followed by postoperative ACD at 35.7%. When optic measurements were considered, postoperative ACD was the most important contributor, followed by anterior corneal surface and its asphericity. A MonteCarlo simulation showed that current limits of refractive assessment are 0.26 and 0.28 D for the phakic and pseudophakic eye, respectively. The most relevant optical elements either do not have available measurement instruments or the existing instruments still need to improve their accuracy. Ray tracing can be used as an optical assessment technique, and may be the correct path for future personalized refractive assessment. Copyright 2013, SLACK Incorporated.

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

    Directory of Open Access Journals (Sweden)

    Zarogoulidis P

    2013-10-01

    Full Text Available Paul Zarogoulidis,1,2 Ioannis Kioumis,1 Konstantinos Porpodis,1 Dionysios Spyratos,1 Kosmas Tsakiridis,3 Haidong Huang,4 Qiang Li,4 J Francis Turner,5 Robert Browning,6 Wolfgang Hohenforst-Schmidt,7 Konstantinos Zarogoulidis1 1Pulmonary Department, G Papanikolaou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece; 2Department of Interventional Pneumology, Ruhrlandklinik, West German Lung Center, University Hospital, University Duisburg-Essen, Essen, Germany; 3Cardiothoracic Surgery Department, Saint Luke Private Hospital of Health Excellence, Thessaloniki, Greece; 4Department of Respiratory Diseases, Shanghai Hospital/First Affiliated Hospital of the Second Military Medical University, Shanghai, People’s Republic of China; 5Pulmonary Medicine, University of Nevada School of Medicine, National Supercomputing Center for Energy and the Environment University of Nevada, Las Vegas, NV, USA; 6Pulmonary and Critical Care Medicine, Interventional Pulmonology, National Naval Medical Center, Walter Reed Army Medical Center, Bethesda, MD, USA; 7II Medical Department, Regional Clinic of Coburg, University of Wuerzburg, Coburg, Germany Abstract: 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

  11. PET motion correction in context of integrated PET/MR: Current techniques, limitations, and future projections.

    Science.gov (United States)

    Gillman, Ashley; Smith, Jye; Thomas, Paul; Rose, Stephen; Dowson, Nicholas

    2017-12-01

    Patient motion is an important consideration in modern PET image reconstruction. Advances in PET technology mean motion has an increasingly important influence on resulting image quality. Motion-induced artifacts can have adverse effects on clinical outcomes, including missed diagnoses and oversized radiotherapy treatment volumes. This review aims to summarize the wide variety of motion correction techniques available in PET and combined PET/CT and PET/MR, with a focus on the latter. A general framework for the motion correction of PET images is presented, consisting of acquisition, modeling, and correction stages. Methods for measuring, modeling, and correcting motion and associated artifacts, both in literature and commercially available, are presented, and their relative merits are contrasted. Identified limitations of current methods include modeling of aperiodic and/or unpredictable motion, attaining adequate temporal resolution for motion correction in dynamic kinetic modeling acquisitions, and maintaining availability of the MR in PET/MR scans for diagnostic acquisitions. Finally, avenues for future investigation are discussed, with a focus on improvements that could improve PET image quality, and that are practical in the clinical environment. © 2017 American Association of Physicists in Medicine.

  12. Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

    Science.gov (United States)

    Lanata, C F; Black, R E

    1991-01-01

    Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

  13. Construction of an experimental simplified model for determining of flow parameters in chemical reactors, using nuclear techniques

    International Nuclear Information System (INIS)

    Araujo Paiva, J.A. de.

    1981-03-01

    The development of a simplified experimental model for investigation of nuclear techniques to determine the solid phase parameters in gas-solid flows is presented. A method for the measurement of the solid phase residence time inside a chemical reactor of the type utilised in the cracking process of catalytic fluids is described. An appropriate radioactive labelling technique of the solid phase and the construction of an eletronic timing circuit were the principal stages in the definition of measurement technique. (Author) [pt

  14. Development of a three-dimensional PIV measurement technique for the experimental study of air bubble collapse phenomena

    International Nuclear Information System (INIS)

    Yang, Y.H.; Hassan, Y.A.; Schmidl, W.D.

    1995-01-01

    Particle image velocimetry (PIV) is a quantitative flow measurement technique. The objective of this study is to develop a new three-dimensional PIV technique for the experimental study of air bubble collapse phenomena. A three-dimensional measurement technique is necessary since bubble collapse is a three-dimensional phenomenon. The investigation of the velocity flow field around a collapsing air bubble can provide detailed three-dimensional quantitative information to help improve the understanding of the related heat transfer processes

  15. Current Parental Depression and Offspring Perceived Self-Competence: A Quasi-Experimental Examination

    Science.gov (United States)

    Class, Quetzal A.; D’Onofrio, Brian M.; Singh, Amber L.; Ganiban, Jody M.; Spotts, E. L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

    2013-01-01

    A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52%) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins (CoT) designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended-family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression. PMID:22692226

  16. Current parental depression and offspring perceived self-competence: a quasi-experimental examination.

    Science.gov (United States)

    Class, Quetzal A; D'Onofrio, Brian M; Singh, Amber L; Ganiban, Jody M; Spotts, E L; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M

    2012-09-01

    A genetically-informed, quasi-experimental design was used to examine the genetic and environmental processes underlying associations between current parental depressive symptoms and offspring perceived self-competence. Participants, drawn from a population-based Swedish sample, were 852 twin pairs and their male (52 %) and female offspring aged 15.7 ± 2.4 years. Parental depressive symptoms were measured using the Center for Epidemiological Studies Depression scale. Offspring perceived self-competence was measured using a modified Harter Perceived Competence Scale. Cousin comparisons and Children of Twins designs suggested that associations between maternal depressive symptoms and offspring perceived self-competence were due to shared genetic/environmental liability. The mechanism responsible for father-offspring associations, however, was independent of genetic factors and of extended family environmental factors, supporting a causal inference. Thus, mothers and fathers may impact offspring perceived self-competence via different mechanisms and unmeasured genetic and environmental selection factors must be considered when studying the intergenerational transmission of cognitive vulnerabilities for depression.

  17. Experimental investigation of focusing and transport of heavy-current electron beams

    International Nuclear Information System (INIS)

    Baranchikov, E.I.; Gordeev, A.V.; Koba, Yu.V.; Korolev, V.D.; Pen'kina, V.S.; Rudakov, L.I.; Smirnov, V.P.; Sukhov, A.D.; Tarumov, E.Z.

    The results of an experimental and theoretical study of beam transfer through transverse magnetic fields are outlined. The injection and transport of an annular relativistic electron beam due to a magnetic trap of acute-angle geometry are experimentally studied

  18. The Orphee reactor current status and proposed enhancement of experimental capabilities

    International Nuclear Information System (INIS)

    Breant, P.

    1990-01-01

    This report provides a description of the Orphee reactor, together with a rapid assessment of its experimental and research capabilities. The plans for enhancing the reactor's experimental capabilities are also presented. (author)

  19. Comparison of image quality and radiation dose between combined automatic tube current modulation and fixed tube current technique in CT of abdomen and pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sanghee (Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan Univ. School of Medicine (Korea, Republic of)); Yoon, Sang-Wook; Yoo, Seung-Min; Kim, Kyoung Ah; Kim, Sang Heum; Lee, Jong Tae (Dept. of Diagnostic Radiology, CHA Bundang Medical Center, CHA Univ. (Korea, Republic of)), email: jansons@cha.ac.kr; Ji, Young Geon (Preventive Medicine, CHA Bundang Medical Center, CHA Univ. (Korea, Republic of))

    2011-12-15

    Background. Tube current is an important determinant of radiation dose and image quality in X-ray-based examination. The combined automatic tube current modulation technique (ATCM) enables automatic adjustment of the tube current in various planes (x-y and z) based on the size and attenuation of the body area scanned. Purpose. To compare image quality and radiation dose of the ATCM with those of a fixed tube current technique (FTC) in CT of the abdomen and pelvis performed with a 16-slice multidetector row CT. Material and Methods. We reviewed 100 patients in whom initial and follow-up CT of the abdomen and pelvis were performed with FTC and ATCM. All acquisition parameters were identical in both techniques except for tube current. We recorded objective image noise in liver parenchyma, subjective image noise and diagnostic acceptability by using a five-point scale, radiation dose, and body mass index (BMI, kg/m2). Data were analyzed with parametric and non-parametric statistical tests. Results. There was no significant difference in image noise and diagnostic acceptability between two techniques. All subjects had acceptable subjective image noise in both techniques. The significant reduction in radiation dose (45.25% reduction) was noted with combined ATCM (P < 0.001). There was a significant linear statistical correlation between BMI and dose reduction (r = -0.78, P < 0.05). Conclusion. The ATCM for CT of the abdomen and pelvis substantially reduced radiation dose while maintaining diagnostic image quality. Patients with lower BMI showed more reduction in radiation dose

  20. Comparison of various structural damage tracking techniques with unknown excitations based on experimental data

    Science.gov (United States)

    Huang, Hongwei; Yang, Jann N.; Zhou, Li

    2009-03-01

    An early detection of structural damages is critical for the decision making of repair and replacement maintenance in order to guarantee a specified structural reliability. Consequently, the structural damage detection, based on vibration data measured from the structural health monitoring (SHM) system, has received considerable attention recently. The traditional time-domain analysis techniques, such as the least square estimation (LSE) method and the extended Kalman filter (EKF) approach, require that all the external excitations (inputs) be available, which may not be the case for some SHM systems. Recently, these two approaches have been extended to cover the general case where some of the external excitations (inputs) are not measured, referred to as the LSE with unknown inputs (LSE-UI) and the EKF with unknown inputs (EKF-UI). Also, new analysis methods, referred to as the sequential non-linear least-square estimation with unknown inputs and unknown outputs (SNLSE-UI-UO) and the quadratic sum-square error with unknown inputs (QSSE-UI), have been proposed for the damage tracking of structures when some of the acceleration responses are not measured and the external excitations are not available. In this paper, these newly proposed analysis methods will be compared in terms of accuracy, convergence and efficiency, for damage identification of structures based on experimental data obtained through a series of experimental tests using a small-scale 3-story building model with white noise excitation. The capability of the LSE-UI, EKF-UI, SNLSE-UI-UO and QSSE-UI approaches in tracking the structural damages will be demonstrated.

  1. Comparative evaluation of a two stroke compressed natural gas mixer design using simulation and experimental techniques

    Energy Technology Data Exchange (ETDEWEB)

    Ramasamy, D.; Bakar, R.A.; Rahim, M.F.; Noor, M.M. [Malaysia Pahang Univ., Pahang (Malaysia). Automotive Focus Group

    2008-07-01

    A study was conducted in which a two-stroke engine was converted for use with bi-fuel, notably compressed natural gas and gasoline. The excessive by-products generated by two-stroke engine combustion can be attributed to the inefficient combustion process. This prototype uniflow-type single-cylinder engine was equipped with a bi-fuel conversion system. A dedicated mixer was also developed to meter the gaseous fuel through the engine intake system. It was designed to meet air and fuel requirement similar to its gasoline counterpart. The mixer was modeled to obtain optimum orifice diameter using three different sizes of 14, 16 and 18 mm respectively. A standard computational fluid dynamics (CFD) software package was used to simulate the flow. A pressure reading was obtained during the prototype test. The drop in pressure across the venturi was shown to be an important parameter as it determined the actual fuel-air ratio in the actual engine. A good agreement of CFD outputs with that of the experimental outputs was recorded. The experimental technique validated the pressure distribution predicted by CFD means on the effects of the three insert rings in the CNG mixer. The simulation exercise can be used to predict the amount of CNG consumed by the engine. It was concluded that the 14 mm throat ring was best suited for the CNG mixer because it provided the best suction. Once the mixer is tested on a real engine, it will clear any doubts as to whether the throat can function at high engine speeds. 5 refs., 3 tabs., 8 figs.

  2. Novel experimental measuring techniques required to provide data for CFD validation

    International Nuclear Information System (INIS)

    Prasser, H.-M.

    2008-01-01

    CFD code validation requires experimental data that characterize the distributions of parameters within large flow domains. On the other hand, the development of geometry-independent closure relations for CFD codes have to rely on instrumentation and experimental techniques appropriate for the phenomena that are to be modelled, which usually requires high spatial and time resolution. The paper reports about the use of wire-mesh sensors to study turbulent mixing processes in single-phase flow as well as to characterize the dynamics of the gas-liquid interface in a vertical pipe flow. Experiments at a pipe of a nominal diameter of 200 mm are taken as the basis for the development and test of closure relations describing bubble coalescence and break-up, interfacial momentum transfer and turbulence modulation for a multi-bubble-class model. This is done by measuring the evolution of the flow structure along the pipe. The transferability of the extended CFD code to more complicated 3D flow situations is assessed against measured data from tests involving two-phase flow around an asymmetric obstacle placed in a vertical pipe. The obstacle, a half-moon-shaped diaphragm, is movable in the direction of the pipe axis; this allows the 3D gas fraction field to be recorded without changing the sensor position. In the outlook, the pressure chamber of TOPFLOW is presented, which will be used as the containment for a test facility, in which experiments can be conducted in pressure equilibrium with the inner atmosphere of the tank. In this way, flow structures can be observed by optical means through large-scale windows even at pressures of up to 5 MPa. The so-called 'Diving Chamber' technology will be used for Pressurized Thermal Shock (PTS) tests. Finally, some important trends in instrumentation for multi-phase flows will be given. This includes the state-of-art of X-ray and gamma tomography, new multi-component wire-mesh sensors, and a discussion of the potential of other non

  3. Novel experimental measuring techniques required to provide data for CFD validation

    International Nuclear Information System (INIS)

    Prasser, H.M.

    2007-01-01

    CFD code validation requires experimental data that characterize distributions of parameters within large flow domains. On the other hand, the development of geometry-independent closure relations for CFD codes have to rely on instrumentation and experimental techniques appropriate for the phenomena that are to be modelled, which usually requires high spatial and time resolution. The presentation reports about the use of wire-mesh sensors to study turbulent mixing processes in the single-phase flow as well as to characterize the dynamics of the gas-liquid interface in a vertical pipe flow. Experiments at a pipe of a nominal diameter of 200 mm are taken as the basis for the development and test of closure relations describing bubble coalescence and break-up, interfacial momentum transfer and turbulence modulation for a multi-bubble-class model. This is done by measuring the evolution of the flow structure along the pipe. The transferability of the extended CFD code to more complicated 3D flow situations is assessed against measured data from tests involving two-phase flow around an asymmetric obstacle placed in a vertical pipe. The obstacle, a half-moon-shaped diaphragm, is movable in the direction of the pipe axis; this allows the 3D gas fraction field to be recorded without changing the sensor position. In the outlook, the pressure chamber of TOPFLOW is presented, which will be used as the containment for a test facility, in which experiments can be conducted in pressure equilibrium with the inner atmosphere of the tank. In this way, flow structures can be observed by optical means through large-scale windows even at pressures of up to 5 MPa. The so-called 'Diving Chamber' technology will be used for Pressurized Thermal Shock (PTS) tests. Finally, some important trends in instrumentation for multi-phase flows will be given. This includes the state-of-art of X-ray and gamma tomography, new multi-component wire-mesh sensors, and a discussion of the potential of

  4. Parallel transmission techniques in magnetic resonance imaging: experimental realization, applications and perspectives

    International Nuclear Information System (INIS)

    Ullmann, P.

    2007-06-01

    The primary objective of this work was the first experimental realization of parallel RF transmission for accelerating spatially selective excitation in magnetic resonance imaging. Furthermore, basic aspects regarding the performance of this technique were investigated, potential risks regarding the specific absorption rate (SAR) were considered and feasibility studies under application-oriented conditions as first steps towards a practical utilisation of this technique were undertaken. At first, based on the RF electronics platform of the Bruker Avance MRI systems, the technical foundations were laid to perform simultaneous transmission of individual RF waveforms on different RF channels. Another essential requirement for the realization of Parallel Excitation (PEX) was the design and construction of suitable RF transmit arrays with elements driven by separate transmit channels. In order to image the PEX results two imaging methods were implemented based on a spin-echo and a gradient-echo sequence, in which a parallel spatially selective pulse was included as an excitation pulse. In the course of this work PEX experiments were successfully performed on three different MRI systems, a 4.7 T and a 9.4 T animal system and a 3 T human scanner, using 5 different RF coil setups in total. In the last part of this work investigations regarding possible applications of Parallel Excitation were performed. A first study comprised experiments of slice-selective B1 inhomogeneity correction by using 3D-selective Parallel Excitation. The investigations were performed in a phantom as well as in a rat fixed in paraformaldehyde solution. In conjunction with these experiments a novel method of calculating RF pulses for spatially selective excitation based on a so-called Direct Calibration approach was developed, which is particularly suitable for this type of experiments. In the context of these experiments it was demonstrated how to combine the advantages of parallel transmission

  5. Current Techniques of Teaching and Learning in Bariatric Surgical Procedures: A Systematic Review.

    Science.gov (United States)

    Kaijser, Mirjam; van Ramshorst, Gabrielle; van Wagensveld, Bart; Pierie, Jean-Pierre

    The gastric sleeve resection and gastric bypass are the 2 most commonly performed bariatric procedures. This article provides an overview of current teaching and learning methods of those techniques in resident and fellow training. A database search was performed on Pubmed, Embase, and the Education Resources Information Center (ERIC) to identify the methods used to provide training in bariatric surgery worldwide. After exclusion based on titles and abstracts, full texts of the selected articles were assessed. Included articles were reviewed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. In total, 2442 titles were identified and 14 full text articles met inclusion criteria. Four publications described an ex vivo training course, and 6 focused on at least 1 step of the gastric bypass procedure. Two randomized controlled trials (RCT) provided high-quality evidence on training aspects. Surgical coaching caused significant improvement of Bariatric Objective Structured Assessment of Technical Skills (BOSATS) scores (3.60 vs. 3.90, p = 0.017) and reduction of technical errors (18 vs. 10, p = 0.003). A preoperative warm-up increased global rating scales (GRS) scores on depth perception (p = 0.02), bimanual dexterity (p = 0.01), and efficiency of movements (p = 0.03). Stepwise education, surgical coaching, warming up, Internet-based knowledge modules, and ex vivo training courses are effective in relation to bariatric surgical training of residents and fellows, possibly shortening their learning curves. Copyright © 2018 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  6. Experimental study of a high-current FEM with a broadband microwave system

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, G.G.; Bratman, V.L.; Ginzburg, N.S. [Institute of Applied Physics, Nizhny Novgorod (Russian Federation)] [and others

    1995-12-31

    One of the main features of FELs and FEMs is the possibility of fast and wideband tuning of the resonant frequency of active media, which can be provided by changing the particle energy. For a frequency adjustable FEM-oscillator, a broadband microwave system, which is simply combined with an electron-optical FEM system and consists of an oversized waveguide and reflectors based on the microwave beams multiplication effect has been proposed and studied successfully in {open_quotes}cold{close_quotes} measurements. Here, the operating ability of a cavity, that includes some key elements of the broadband microwave system, was tested in the presence of an electron beam. To provide large particle oscillation velocities in a moderate undulator field and the presence of a guide magnetic field, the FEM operating regime of double resonance was chosen. In this regime the cyclotron as well as undulator resonance conditions were satisfied. The FEM-oscillator was investigated experimentally on a high-current accelerator {open_quotes}Sinus-6{close_quotes} that forms an electron beam with particle energy 500keV and pulse duration 25ns. The aperture with a diameter 2.5mm at the center of the anode allows to pass through only the central fraction of the electron beam with a current about 100A and a small spread of longitudinal velocities of the particles. Operating transverse velocity was pumped into the electron beam in the pulse plane undulator of a 2.4cm period. The cavity with a frequency near 45GHz consists of a square waveguide and two reflectors. The broadband up-stream reflector based on the multiplication effect had the power reflectivity coefficient more than 90% in the frequency band 10% for the H{sup 10} wave of the square waveguide with the maximum about 100% at a frequency 45GHz. The down-stream narrow-band Bragg reflector had the power reflection coefficient approximately 80% in the frequency band of 4% near 45GHz for the operating mode.

  7. Experimental Investigation of the Performance of Tilt Current Meters in Wave-Dominated Flows

    DEFF Research Database (Denmark)

    Hansen, Asger Bendix; Carstensen, Stefan

    2017-01-01

    In recent years, tilt current meters (TCMs) have received renewed attention as they provide an inexpensive method for measuring currents in the coastal zone. However, previous studies focused mainly on current dominated flows or the current component of the flow. This study investigates the perfo...

  8. Studies of nematic to smectic-A phase transitions using synchrotron radiation. Experimental techniques and experiments

    International Nuclear Information System (INIS)

    Christensen, F.

    1981-10-01

    High resolution X-ray diffraction on liquid crystals, with a triple-axis spectrometer, was initiated 4-5 years ago, using rotating-anode sources. The triple-axis spectrometer, built at Risoe, is permanently positioned at the DORIS storage ring. Triple-axis X-ray spectrometer work in general and especially at the synchrotron source is a new field and a description of the techniques used is given. The experiments described are studies of the nematic to smectic-A phase transition in liquid crystals. The first is a study of the monomolecular liquid crystal 8-barS5 (C 8 H 17 O-phi-COS-phi-C 5 H 11 , where phi denotes a benzene ring). The second experimental study is one of the reentrance phenomenon in the ternary mixture: 5CTsub(.09):7CBsub(.x):80CBsub(.91-x); where 5CT(C 5 H 11 -phi-phi-phi-CN) and 7CB(C 7 H 15 -phi-phi-CN) have only a nematic phase and not the smectic-A phase. The results are interpreted in terms of Landau theory. Finally, a frame is given for discussing the nature of the smectic-A phase and an experiment is proposed to explore the nature of the smectic-A phase together with detailed calculations of (001)- and (002)-lineshapes for the smectic-A phase. (Auth.)

  9. Improved Understanding of Implosion Symmetry through New Experimental Techniques Connecting Hohlraum Dynamics with Laser Beam Deposition

    Science.gov (United States)

    Ralph, Joseph; Salmonson, Jay; Dewald, Eduard; Bachmann, Benjamin; Edwards, John; Graziani, Frank; Hurricane, Omar; Landen, Otto; Ma, Tammy; Masse, Laurent; MacLaren, Stephen; Meezan, Nathan; Moody, John; Parrilla, Nicholas; Pino, Jesse; Sacks, Ryan; Tipton, Robert

    2017-10-01

    Understanding what affects implosion symmetry has been a challenge for scientists designing indirect drive inertial confinement fusion experiments on the National Ignition Facility (NIF). New experimental techniques and data analysis have been employed aimed at improving our understanding of the relationship between hohlraum dynamics and implosion symmetry. Thin wall imaging data allows for time-resolved imaging of 10 keV Au l-band x-rays providing for the first time on the NIF, a spatially resolved measurement of laser deposition with time. In the work described here, we combine measurements from the thin wall imaging with time resolved views of the interior of the hohlraum. The measurements presented are compared to hydrodynamic simulations as well as simplified physics models. The goal of this work is to form a physical picture that better explains the relationship of the hohlraum dynamics and capsule ablator on laser beam propagation and implosion symmetry. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

  10. Evaluation of in-vehicle HMI using occlusion techniques: experimental results and practical implications.

    Science.gov (United States)

    Baumann, Martin; Keinath, Andreas; Krems, Josef F; Bengler, Klaus

    2004-05-01

    Despite the usefulness of new on-board information systems one has to be concerned about the potential distraction effects that they impose on the driver. Therefore, methods and procedures are necessary to assess the visual demand that is connected to the usage of an on-board system. The occlusion-method is considered a strong candidate as a procedure for evaluating display designs with regard to their visual demand. This paper reports results from two experimental studies conducted to further evaluate this method. In the first study, performance in using an in-car navigation system was measured under three conditions: static (parking lot), occlusion (shutter glasses), and driving. The results show that the occlusion-procedure can be used to simulate visual requirements of real traffic conditions. In a second study the occlusion method was compared to a global evaluation criterion based on the total task time. It can be demonstrated that the occlusion method can identify tasks which meet this criterion, but are yet irresolvable under driving conditions. It is concluded that the occlusion technique seems to be a reliable and valid method for evaluating visual and dialogue aspects of in-car information systems.

  11. Zeta potential of microfluidic substrates: 1. Theory, experimental techniques, and effects on separations.

    Science.gov (United States)

    Kirby, Brian J; Hasselbrink, Ernest F

    2004-01-01

    This paper summarizes theory, experimental techniques, and the reported data pertaining to the zeta potential of silica and silicon with attention to use as microfluidic substrate materials, particularly for microchip chemical separations. Dependence on cation concentration, buffer and cation type, pH, cation valency, and temperature are discussed. The Debye-Hückel limit, which is often correctly treated as a good approximation for describing the ion concentration in the double layer, can lead to serious errors if it is extended to predict the dependence of zeta potential on the counterion concentration. For indifferent univalent electrolytes (e.g., sodium and potassium), two simple scalings for the dependence of zeta potential on counterion concentration can be derived in high- and low-zeta limits of the nonlinear Poisson-Boltzman equation solution in the double layer. It is shown that for most situations relevant to microchip separations, the high-zeta limit is most applicable, leading to the conclusion that the zeta potential on silica substrates is approximately proportional to the logarithm of the molar counterion concentration. The zeta vs. pH dependence measurements from several experiments are compared by normalizing the zeta based on concentration.

  12. Physically-Based Interactive Flow Visualization Based on Schlieren and Interferometry Experimental Techniques

    KAUST Repository

    Brownlee, C.

    2011-11-01

    Understanding fluid flow is a difficult problem and of increasing importance as computational fluid dynamics (CFD) produces an abundance of simulation data. Experimental flow analysis has employed techniques such as shadowgraph, interferometry, and schlieren imaging for centuries, which allow empirical observation of inhomogeneous flows. Shadowgraphs provide an intuitive way of looking at small changes in flow dynamics through caustic effects while schlieren cutoffs introduce an intensity gradation for observing large scale directional changes in the flow. Interferometry tracks changes in phase-shift resulting in bands appearing. The combination of these shading effects provides an informative global analysis of overall fluid flow. Computational solutions for these methods have proven too complex until recently due to the fundamental physical interaction of light refracting through the flow field. In this paper, we introduce a novel method to simulate the refraction of light to generate synthetic shadowgraph, schlieren and interferometry images of time-varying scalar fields derived from computational fluid dynamics data. Our method computes physically accurate schlieren and shadowgraph images at interactive rates by utilizing a combination of GPGPU programming, acceleration methods, and data-dependent probabilistic schlieren cutoffs. Applications of our method to multifield data and custom application-dependent color filter creation are explored. Results comparing this method to previous schlieren approximations are finally presented. © 2011 IEEE.

  13. The effect of transcranial direct current stimulation on experimentally induced heat pain.

    Science.gov (United States)

    Aslaksen, Per M; Vasylenko, Olena; Fagerlund, Asbjørn J

    2014-06-01

    Transcranial direct current stimulation (tDCS) is a non-invasive neuromodulatory technique that can affect human pain perception. Placebo effects are present in most treatments and could therefore also interact with treatment effects in tDCS. The present study investigated whether short-term tDCS reduced heat pain intensity, stress, blood pressure and increased heat pain thresholds in healthy volunteers when controlling for placebo effects. Seventy-five (37 females) participants were randomized into three groups: (1) active tDCS group receiving anodal tDCS (2 mA) for 7 min to the primary motor cortex (M1), (2) placebo group receiving the tDCS electrode montage but only active tDCS stimulation for 30 s and (3) natural history group that got no tDCS montage but the same pain stimulation as the active tDCS and the placebo group. Heat pain was induced by a PC-controlled thermode attached to the left forearm. Pain intensity was significantly lower in the active tDCS group when examining change scores (pretest-posttest) for the 47 °C condition. The placebo group displayed lower pain compared with the natural history group, displaying a significant placebo effect. In the 43 and 45 °C conditions, the effect of tDCS could not be separated from placebo effects. The results revealed no effects on pain thresholds. There was a tendency that active tDCS reduced stress and systolic blood pressure, however, not significant. In sum, tDCS had an analgesic effect on high-intensity pain, but the effect of tDCS could not be separated from placebo effects for medium and low pain.

  14. In Situ Determination of Thermal Profiles during Czochralski Silicon Crystal Growth by an Eddy Current Technique.

    Science.gov (United States)

    Choe, Kwang Su.

    An eddy current testing method was developed to continuously monitor crystal growth process and determine thermal profiles in situ during Czochralski silicon crystal growth. The work was motivated by the need to improve the quality of the crystal by controlling thermal gradients and annealing history over the growth cycle. The experimental concept is to monitor intrinsic electrical conductivities of the growing crystal and deduce temperature values from them. The experiments were performed in a resistance-heated Czochralski puller with a 203 mm (8 inch) diameter crucible containing 6.5 kg melt. The silicon crystals being grown were about 80 mm in diameter and monitored by an encircling sensor operating at three different test frequencies (86, 53 and 19 kHz). A one-dimensional analytical solution was employed to translate the detected signals into electrical conductivities. In terms of experiments, the effects of changes in growth condition, which is defined by crystal and crucible rotation rates, crucible position, pull rate, and hot-zone configuration, were investigated. Under a given steady-state condition, the thermal profile was usually stable over the entire length of crystal growth. The profile shifted significantly, however, when the crucible rotation rate was kept too high. As a direct evidence to the effects of melt flow on heat transfer process, a thermal gradient minimum was observed about the crystal/crucible rotation combination of 20/-10 rpm cw. The thermal gradient reduction was still most pronounced when the pull rate or the radiant heat loss to the environment was decreased: a nearly flat axial thermal gradient was achieved when either the pull rate was halved or the height of the exposed crucible wall was effectively doubled. Under these conditions, the average axial thermal gradient along the surface of the crystal was about 4-5 ^{rm o}C/mm. Regardless of growth condition, the three-frequency data revealed radial thermal gradients much larger

  15. Two current experimental problems in heavy lepton physics: tau decay modes and close mass pairs

    International Nuclear Information System (INIS)

    Perl, M.L.

    1987-08-01

    This paper investigates tau lepton decay modes and close-mass lepton pairs. The major part of the paper discusses branching functions from experimental and theoretical viewpoints. Finally, the lack of experimental signatures of close-mass lepton pairs are reviewed. 15 refs., 2 figs., 11 tabs

  16. Two current experimental problems in heavy lepton physics: tau decay modes and close mass pairs

    Energy Technology Data Exchange (ETDEWEB)

    Perl, M.L.

    1987-08-01

    This paper investigates tau lepton decay modes and close-mass lepton pairs. The major part of the paper discusses branching functions from experimental and theoretical viewpoints. Finally, the lack of experimental signatures of close-mass lepton pairs are reviewed. 15 refs., 2 figs., 11 tabs. (JDH)

  17. 'I think it will eventually be done away with': Attitudes among healthcare professionals towards the current system of animal experimentation.

    Science.gov (United States)

    Dignon, Andrée

    2016-08-01

    This article describes a study of attitudes to the current system of animal experimentation (for the production of health interventions) among 52 UK healthcare professionals. These healthcare professionals participated in three separate focus groups (of 18, 17 and 17 participants) and were invited to respond to the question 'what is your opinion about the current system of animal testing?' The study focused specifically on their views of the current system (rather than their views of animal testing in general). The healthcare professionals were critical of the current system, particularly with regard to regulation, secrecy, validity, unnecessary suffering and welfare. © The Author(s) 2014.

  18. Improvement of ISI techniques by multi-frequency eddy current testing method for steam generator tube in PWR plant

    International Nuclear Information System (INIS)

    Endo, Takashi; Kamimura, Takeo; Nishihara, Masatoshi; Araki, Yasuo; Fukui, Shigetaka.

    1982-05-01

    Eddy current flaw detection techniques are applied to the in-service inspection (ISI) of steam generator tubes in pressurized water reactors (PWR) plant. To improve the reliability and operating efficiency of the plants, efforts are being made to develop eddy current testing methods of various kinds. Multi-frequency eddy current testing method, one of new method, has recently been applied to actual heat exchanger tubes, contributing to the improvement of the detectability and signal evaluation of the ISI. The outline of multi-frequency eddy current testing method and its effects on the improvement of flaw detecting and signal evaluation accuracy are described. (author)

  19. Experimental device, corresponding forward model and processing of the experimental data using wavelet analysis for tomographic image reconstruction applied to eddy current nondestructive evaluation

    International Nuclear Information System (INIS)

    Joubert, P.Y.; Madaoui, N.

    1999-01-01

    In the context of eddy current non destructive evaluation using a tomographic image reconstruction process, the success of the reconstruction depends not only on the choice of the forward model and of the inversion algorithms, but also on the ability to extract the pertinent data from the raw signal provided by the sensor. We present in this paper, an experimental device designed for imaging purposes, the corresponding forward model, and a pre-processing of the experimental data using wavelet analysis. These three steps implemented with an inversion algorithm, will allow in the future to perform image reconstruction of 3-D flaws. (authors)

  20. An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751.

    Science.gov (United States)

    Balan, A S S; Vijayaraghavan, L; Krishnamurthy, R; Kuppan, P; Oyyaravelu, R

    2016-09-01

    The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the ​ effects of different grinding environments such as dry, minimum quantity lubrication (MQL) and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2) and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50-65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.

  1. An experimental assessment on the performance of different lubrication techniques in grinding of Inconel 751

    Directory of Open Access Journals (Sweden)

    A.S.S. Balan

    2016-09-01

    Full Text Available The application of emulsion for combined heat extraction and lubrication requires continuous monitoring of the quality of emulsion to sustain a desired grinding environment; this is applicable to other grinding fluids as well. Thus to sustain a controlled grinding environment, it is necessary to adopt an effectively lubricated wheel-work interface. The current study was undertaken to assess experimentally the ​ effects of different grinding environments such as dry, minimum quantity lubrication (MQL and Cryo-MQL on performance, such as grinding force, temperature, surface roughness and chip morphology on Inconel 751, a higher heat resistance material posing thermal problems and wheel loading. The results show that grinding with the combination of both liquid nitrogen (LN2 and MQL lowers temperature, cutting forces, and surface roughness as compared with MQL and dry grinding. Specific cutting energy is widely used as an inverse measure of process efficiency in machining. It is found from the results that specific cutting energy of Cryo-MQL assisted grinding is 50–65% lower than conventional dry grinding. The grindability of Inconel 751 superalloy can be enhanced with Cryo-MQL condition.

  2. Applications of structural and spectroscopic techniques to the experimental and theoretical study of new luminescent materials

    International Nuclear Information System (INIS)

    Navarro Ahumada, Gustavo Adolfo

    2001-01-01

    This thesis discusses the general problem of the radiation-matter interaction in the case of a family of crystals known as elpasolites, which belong to the spatial group FM3M(O 5 H ). These systems present complications, from a theoretical as well as experimental point of view. The study was carried out in stoichiometric elpasolite type systems, characterized by empirical formulas of the general type Cs2NaLnCl 6 where Ln is a lanthanide of the first series of internal transition with electronic configurations for the trivalent state (Ln +3 ) of the form ∫ 1 → ∫ 13 . An analysis of the atomic spectra for these gaseous phase ions shows a diversity of permitted states, due to relativistic and non relativistic effects. Systems with positive trivalent lanthanide ions of the form Dy 3+ (∫ 9 ), Ho 3+ (∫ 10 ) y Er 3+ (∫ 11 ) have been selected at the level of the stoichiometric elpasolites and are characterized by complex energetic spectra. A careful experimental study of the emission states suggests that the elpasolite of Er 3+ is interesting, and its study is very relevant. The assignments and identifications of the peaks, during absorption as well as during emission, are more precise for the configuration Er 3+ , and careful studies show that fluorescence between terminal states with the rule of selection for the total orbital angular momentum:ΔJ = 6 is observed for this system. A declining cascade that can reasonably explain the unsuspected related spectral intensity, in the order of 10-9, is presented and suggested although a value was predicted for the electric dipolar force of lesser than 4 orders of magnitude what was observed. This problem is discussed and a mechanism is proposed for spectral intensities associated with two emissions characterized by ΔJ = 4 (electric hexadecapole) and ΔJ = 2 (electric cuadrupole). The laboratory tests made, include synthesis by solid state reactions of Dy 3+ and Ho 3+ , type elpasolites, structural characterization

  3. Comprehensive Characterization of Palygorskite from Torrejon el Rubio (Spain) Based on Experimental Techniques and Theoretical DFT Studies

    International Nuclear Information System (INIS)

    Fernandez, A.M.; Timon, V.; Cubero, J. J.; Sanchez-Ledesma, D. M.; Gutierrez-Nebot, L.; Martinez, J. J.; Romero, C.; Labajo, M.; Melon, A.; Barrios, I.

    2013-01-01

    New data about the physico-chemical, microstructural and crystal-chemical properties of the mineral paligorskite from Torrejon el Rubio (Caceres, Spain) were obtained by a combination of experimental techniques (XRD, FRX, FTIR, TG-DSC, SEM and chemical analyses), as well as geometry optimization by means of the Density Functional Theory (DFT). This study demonstrates the applicability of the mixed theoretical-experimental work to characterize and understand the properties of clay minerals used in technological applications and environmental remediation. (Author)

  4. Comprehensive Characterization of Palygorskite from Torrejon el Rubio (Spain) Based on Experimental Techniques and Theoretical DFT Studies

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.M.; Timon, V.; Cubero, J. J.; Sanchez-Ledesma, D. M.; Gutierrez-Nebot, L.; Martinez, J. J.; Romero, C.; Labajo, M.; Melon, A.; Barrios, I.

    2013-10-01

    New data about the physico-chemical, microstructural and crystal-chemical properties of the mineral paligorskite from Torrejon el Rubio (Caceres, Spain) were obtained by a combination of experimental techniques (XRD, FRX, FTIR, TG-DSC, SEM and chemical analyses), as well as geometry optimization by means of the Density Functional Theory (DFT). This study demonstrates the applicability of the mixed theoretical-experimental work to characterize and understand the properties of clay minerals used in technological applications and environmental remediation. (Author)

  5. How do laboratory embryo transfer techniques affect IVF outcomes? A review of current literature.

    Science.gov (United States)

    Sigalos, George; Triantafyllidou, Olga; Vlahos, Nikos

    2017-04-01

    Over the last few years, many studies have focused on embryo selection methods, whereas little attention has been given to the standardization of the procedure of embryo transfer. In this review, several parameters of the embryo transfer procedure are examined, such as the: (i) culture medium volume and loading technique; (ii) syringe and catheters used for embryo transfer; (iii) viscosity and composition of the embryo transfer medium; (iv) environment of embryo culture; (v) timing of embryo transfer; (vi) and standardization of the embryo transfer techniques. The aim of this manuscript is to review these factors and compare the existing embryo transfer techniques and highlight the need for better embryo transfer standardization.

  6. Experimental Technique for Producing and Recording Precise Particle Impacts on Transparent Window Materials

    Science.gov (United States)

    Gray, Perry; Guven, Ibrahim

    2016-01-01

    A new facility for making small particle impacts is being developed at NASA. Current sand/particle impact facilities are an erosion test and do not precisely measure and document the size and velocity of each of the impacting particles. In addition, evidence of individual impacts is often obscured by subsequent impacts. This facility will allow the number, size, and velocity of each particle to be measured and adjusted. It will also be possible to determine which particle produced damage at a given location on the target. The particle size and velocity will be measured by high speed imaging techniques. Information as to the extent of damage and debris from impacts will also be recorded. It will be possible to track these secondary particles, measuring size and velocity. It is anticipated that this additional degree of detail will provide input for erosion models and also help determine the impact physics of the erosion process. Particle impacts will be recorded at 90 degrees to the particle flight path and also from the top looking through the target window material.

  7. Effect of Coil Current on the Properties of Hydrogenated DLC Coatings Fabricated by Filtered Cathodic Vacuum Arc Technique

    Science.gov (United States)

    Liao, Bin; Ouyang, Xiaoping; Zhang, Xu; Wu, Xianying; Bian, Baoan; Ying, Minju; Jianwu, Liu

    2018-01-01

    We successfully prepared hydrogenated DLC (a-C:H) with a thickness higher than 25 μm on stainless steel using a filtered cathode vacuum arc (FCVA) technique. The structural and mechanical properties of DLC were systematically analyzed using different methods such as x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, Vickers hardness, nanohardness, and friction and wear tests. The effect of coil current on the arc voltage, ion current, and mechanical properties of resultant films was systematically investigated. The novelty of this study is the fabrication of DLC with Vickers hardness higher than 1500 HV, in the meanwhile with the thickness higher than 30 μm through varying the coil current with FCVA technique. The results indicated that the ion current, deposition rate, friction coefficient, and Vickers hardness of DLC were significantly affected by the magnetic field inside the filtered duct.

  8. Emerging optical techniques in advanced cystoscopy for bladder cancer diagnosis: A review of the current literature

    NARCIS (Netherlands)

    Cauberg Evelyne, C. C.; de La Rosette, Jean J. M. C. H.; de Reijke, Theo M.

    2011-01-01

    The current standard for the diagnosis and followup of bladder cancer remains white light cystoscopy, despite its well-known limitations. The aim of this paper is to review the current literature on three optical diagnostics that have been developed to improve the performance of white light

  9. Space Vector Modulation Technique to Reduce Leakage Current of a Transformerless Three-Phase Four-Leg Photovoltaic System

    Directory of Open Access Journals (Sweden)

    F. Hasanzad

    2017-06-01

    Full Text Available Photovoltaic systems integrated to the grid have received considerable attention around the world. They can be connected to the electrical grid via galvanic isolation (transformer or without it (transformerless. Despite making galvanic isolation, low frequency transformer increases size, cost and losses. On the other hand, transformerless PV systems increase the leakage current (common-mode current, (CMC through the parasitic capacitors of the PV array. Inverter topology and switching technique are the most important parameters the leakage current depends on. As there is no need to extra hardware for switching scheme modification, it's an economical method for reducing leakage current. This paper evaluates the effect of different space vector modulation techniques on leakage current for a two-level three-phase four-leg inverter used in PV system. It proposes an efficient space vector modulation method which decreases the leakage current to below the quantity specified in VDE-0126-1-1 standard. furthermore, some other characteristics of the space vector modulation schemes that have not been significantly discussed for four-leg inverter, are considered, such as, modulation index, switching actions per period, common-mode voltage (CMV, and total harmonic distortion (THD. An extend software simulation using MATLAB/Simulink is performed to verify the effectiveness of the modulation technique.

  10. Axial mercury segregation in direct current operated low-pressure argon-mercury gas discharge: Part I. Experimental

    NARCIS (Netherlands)

    Gielen, J.W.A.M.; de Groot, S.; Dijk, van J.; Mullen, van der J.J.A.M.

    2004-01-01

    Due to cataphoresis, axial segregation of mercury will occur when the gas discharge of a fluorescent lamp is operated by means of a direct current. A consequence of this is a non-uniform axial luminance distribution along the lamp. To determine the degree of axial mercury segregation experimentally,

  11. Faculty perceptions of the strengths, weaknesses and future prospects of the current medical undergraduate experimental physiology curriculum in Gujarat, India.

    Science.gov (United States)

    Paralikar, Swapnil; Shah, Chinmay

    2015-01-01

    Over the past several years, an opinion has emerged in India that the current practical curricula in medical schools fail to meet many of the objectives for which they were instituted. Hence, this study has assessed the perception of physiology faculty members regarding the current experimental physiology curriculum in one Indian state, Gujarat. The faculty were of the opinion that many of the topics currently taught in experimental physiology (amphibian nerve-muscle and heart muscle experiments) were outdated and clinically irrelevant: Therefore, the faculty advocated that duration of teaching time devoted to some of these topics should be reduced and topics with clinical relevance should be introduced at the undergraduate level. The faculty also felt that more emphasis should be laid on highlighting the clinical aspect related to each concept taught in experimental physiology . Moreover, a majority of faculty members were in favour of replacing the current practice in Gujarat of teaching experimental physiology only by explanation of graphs obtained from experiments conducted in the previous years, with computer assisted learning in small groups.

  12. New current control based MPPT technique for single stage grid connected PV systems

    International Nuclear Information System (INIS)

    Jain, Sachin; Agarwal, Vivek

    2007-01-01

    This paper presents a new maximum power point tracking algorithm based on current control for a single stage grid connected photovoltaic system. The main advantage of this algorithm comes from its ability to predict the approximate amplitude of the reference current waveform or power that can be derived from the PV array with the help of an intermediate variable β. A variable step size for the change in reference amplitude during initial tracking helps in fast tracking. It is observed that if the reference current amplitude is greater than the array capacity, the system gets unstable (i.e. moves into the positive slope region of the p-v characteristics of the array). The proposed algorithm prevents the PV system from entering the positive slope region of the p-v characteristics. It is also capable of restoring stability if the system goes unstable due to a sudden environmental change. The proposed algorithm has been tested on a new single stage grid connected PV configuration recently developed by the authors to feed sinusoidal current into the grid. The system is operated in a continuous conduction mode to realize advantages such as low device current stress, high efficiency and low EMI. A fast MPPT tracker with single stage inverter topology operating in CCM makes the overall system highly efficient. Specific cases of the system, operating in just discontinuous current mode and discontinuous current mode and their relative merits and demerits are also discussed

  13. Current and Ongoing Internet Crime Tendencies and Techniques. Preventive Legislation Measures in Romania

    Directory of Open Access Journals (Sweden)

    Florin Postolache

    2010-06-01

    Full Text Available Internet crime techniques that pilfer from victims millions each year continue to plague the Internet through a range of methods. Trends and techniques identified by many organizations along with itsdescription are followed by preventative measures that will support you in being informed prior to entering into dealings and transactions over the Internet. Techniques as Auction Fraud, Counterfeit Cashier's Check, Credit Card Fraud, Debt Elimination, Parcel Courier Email Scheme, Employment/Business Opportunities,Escrow Services Fraud, Identity Theft, Internet Extortion, Investment Fraud, Lotteries, Nigerian Letter or "419", Phishing/Spoofing, Ponzi/Pyramid, Reshipping, Spam, Third Party Receiver of Funds are clarified in this paper and, also the internet crime prevention and legislative measures are treated, too.

  14. Elemental analysis of biological materials. Current problems and techniques with special reference to trace elements

    International Nuclear Information System (INIS)

    1980-01-01

    Selected techniques were reviewed for the assay of trace and minor elements in biological materials. Other relevant information is also presented on the need for such analyses, sampling, sample preparation and analytical quality control. In order to evaluate and compare the applicability of the various analytical techniques on a meaningful and objective basis, the materials chosen for consideration were intended to be typical of a wide range of biological matrics of different elemental compositions, namely Bowen's kale, representing a plant material, and NBS bovine liver, IAEA animal muscle, and blood serum, representing animal tissues. The subject is reviewed under the following headings: on the need for trace element analyses in the life sciences (4 papers); sampling and sample preparation for trace element analysis (2 papers); analytical techniques for trace and minor elements in biological materials (7 papers); analytical quality control (2 papers)

  15. Current practice and feasibility in microlaryngeal surgery: microsurgical pressing excision technique.

    Science.gov (United States)

    Lee, Ka-Wo; Chiang, Feng-Yu

    2009-12-01

    Since the introduction of endolaryngeal microsurgery, several basic microsurgical techniques have been described for the removal of benign vocal fold lesions. These techniques include conventional incision or dissection, bimanual retraction and cutting, microflap technique and the CO2 laser. Until recently, only a few microsurgical methods have emerged as new choices for the treatment of benign vocal fold lesions. This article introduces an innovative method that can precisely remove benign sessile vocal fold lesions with epithelial keratosis or hyperplasia without jeopardizing the intermediate or deep layer of the lamina propria. Instead of using conventional vertically opening microinstruments, this microsurgical pressing excision technique (MPET) utilized two pairs of custom-made horizontally left-opening or right-opening, curved microscissors/curved cupped microforceps to remove right or left vocal fold lesions accordingly. Using one instrument at a time, the lesion was subsequently removed with the microscissors and microforceps in a press-evert-cut manner. Among a total of 553 cases, the treatment results were satisfactory, with 520 (94%) patients retaining a satisfactory/normal (G0) voice 2 months postoperatively. More importantly, no patient's voice was worse postoperatively. This technique has several advantages: utilizing one instrument at a time can maximize exposure of the narrow endoscopic view, adjusting the pressing force makes precise excision easy in a well controlled horizontal plane. The MPET is particularly useful for removing sessile vocal nodules (especially those with epithelial keratosis), epithelial hyperplasia and leukoplakia in patients with difficult endolaryngeal exposure. This could be a well tolerated and precise microsurgical technique.

  16. Numerical and experimental analysis of eddy currents induced in tokamak machines

    International Nuclear Information System (INIS)

    Takahashi, T.; Takahashi, G.; Kazawa, Y.; Suzuki, Y.

    1977-01-01

    This paper deals with eddy current phenomena in Tokamak machines. A numerical method is presented which will permit eddy currents to be calculated. Examples of numerical results and a discussion of the JT-60 are shown. Calculations are checked by measurements in basic models

  17. Overview of Alternative Bunching and Current-shaping Techniques for Low-Energy Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Piot, Philippe [Northern Illinois U.

    2015-12-01

    Techniques to bunch or shape an electron beam at low energies (E <15 MeV) have important implications toward the realization of table-top radiation sources [1] or to the design of compact multi-user free-electron lasers[2]. This paper provides an overview of alternative methods recently developed including techniques such as wakefield-based bunching, space-charge-driven microbunching via wave-breaking [3], ab-initio shaping of the electron-emission process [4], and phase space exchangers. Practical applications of some of these methods to foreseen free-electron-laser configurations are also briefly discussed [5].

  18. Experimental Study of Hydroxy Gas (HHO) Production with Variation in Current, Voltage and Electrolyte Concentration

    Science.gov (United States)

    Alam, Noor; Pandey, K. M.

    2017-08-01

    In this paper, work has been carried out experimentally for the investigation of the effects of variation incurrent, voltage, temperature, chemical concentration and reaction time on the amount of hydroxy gas produced. Further effects on the overall electrolysis efficiency of advance alkaline water is also studied. The hydroxy gas (HHO) has been produced experimentally by the electrolysis of alkaline water with parallel plate electrode of 316L-grade stainless steel. The electrode has been selected on the basis of corrosion resistance and inertness with respect to electrolyte (KOH). The process used for the production of HHO is conventional as compared to the other production processes because of reduced energy consumption, less maintenance and low setup cost. From the experimental results, it has been observed that with increase in voltage, temperature and electrolyte concentration of alkaline solution, the production of hydroxy gas has increased about 30 to 40% with reduction in electrical energy consumption.

  19. Effect of an experimental zirconia-silica coating technique on micro tensile bond strength of zirconia in different priming conditions

    NARCIS (Netherlands)

    Chen, C.; Kleverlaan, C.J.; Feilzer, A.J.

    2012-01-01

    Objectives This study aimed to evaluate the adhesive properties of a MDP-containing resin cement to a colored zirconia ceramic, using an experimental zirconia-silica coating technique with different priming conditions. Methods 18 zirconia ceramic discs (Cercon base colored) were divided into two

  20. Experimental investigation on 3D-SEM reconstructions of a wire gauge using stereo-pair technique

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, G.; Cantatore, Angela

    2011-01-01

    In this work an experimental investigation is addressed concerning 3D-SEM reconstructions obtained from the so-called stereo-pair technique. Three-dimensional topography of an object can be derived from two SEM images acquired from two different angles, through item rotation by means of the SEM...

  1. NUMERICAL RESEARCH TECHNIQUES OF MAGNETIC FIELDS GENERATED BY INDUCTION CURRENTS IN A MASSIVE CONDUCTOR

    OpenAIRE

    Tchernykh A. G.

    2015-01-01

    We consider the technology of application of numerical methods in the educational process in physics on the example of a study of the magnetic field induced by induction currents in a cylindrical conductor in a quasi-stationary magnetic field. Here is given the numerical calculation of the real and imaginary parts of the Bessel functions of complex argument. The listing of the program of drawing the graphs of the radial dependence of the amplitude and phase shift of the inductive currents fie...

  2. Current measurement system utilizing cryogenic techniques for the absolute measurement of the magnetic flux quantum

    International Nuclear Information System (INIS)

    Endo, T.; Murayama, Y.; Sakamoto, Y.; Sakuraba, T.; Shiota, F.

    1989-01-01

    A series of systems composed of cryogenic devices such as a Josephson potentiometer and a cryogenic current comparator has been proposed and developed to precisely measure a current with any value up to 1 A. These systems will be used to measure the injected electrical energy with an uncertainty of the order of 0.01 ppm or less in the absolute measurement of the magnetic flux quantum by superconducting magnetic levitation. Some preliminary experiments are described

  3. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    Science.gov (United States)

    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.

  4. Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

    International Nuclear Information System (INIS)

    Parsapour, Amir; Dehkordi, Behzad Mirzaeian; Moallem, Mehdi

    2015-01-01

    In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated

  5. Predicting core losses and efficiency of SRM in continuous current mode of operation using improved analytical technique

    Energy Technology Data Exchange (ETDEWEB)

    Parsapour, Amir, E-mail: amirparsapour@gmail.com [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Dehkordi, Behzad Mirzaeian, E-mail: mirzaeian@eng.ui.ac.ir [Department of Electrical Engineering, University of Isfahan, Isfahan (Iran, Islamic Republic of); Moallem, Mehdi, E-mail: moallem@cc.iut.ac.ir [Department of Electrical Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2015-03-15

    In applications in which the high torque per ampere at low speed and rated power at high speed are required, the continuous current method is the best solution. However, there is no report on calculating the core loss of SRM in continuous current mode of operation. Efficiency and iron loss calculation which are complex tasks in case of conventional mode of operation is even more involved in continuous current mode of operation. In this paper, the Switched Reluctance Motor (SRM) is modeled using finite element method and core loss and copper loss of SRM in discontinuous and continuous current modes of operation are calculated using improved analytical techniques to include the minor loop losses in continuous current mode of operation. Motor efficiency versus speed in both operation modes is obtained and compared. - Highlights: • Continuous current method for Switched Reluctance Motor (SRM) is explained. • An improved analytical technique is presented for SRM core loss calculation. • SRM losses in discontinuous and continuous current operation modes are presented. • Effect of mutual inductances on SRM performance is investigated.

  6. Numerical and experimental studies of stack shunt current for vanadium redox flow battery

    International Nuclear Information System (INIS)

    Yin, Cong; Guo, Shaoyun; Fang, Honglin; Liu, Jiayi; Li, Yang; Tang, Hao

    2015-01-01

    Highlights: • A coupled three-dimensional model of VRB cell stack is developed. • Shunt current of the stack is studied with the model and experiment. • Increased electrolyte resistance in channel and manifold lowers the shunt current. • Shunt current loss increases with stack cell number nonlinearly. - Abstract: The stack shunt current of VRB (vanadium redox flow battery) was investigated with experiments and 3D (three-dimensional) simulations. In the proposed model, cell voltages and electrolyte conductivities were calculated based on electrochemical reaction distributions and SOC (state of charge) values, respectively, while coulombic loss was estimated according to shunt current and vanadium ionic crossover through membrane. Shunt current distributions and coulombic efficiency are analyzed in terms of electrolyte conductivities and stack cell numbers. The distributions of cell voltages and shunt currents calculated with proposed model are validated with single cell and short stack tests. The model can be used to optimize VRB stack manifold and channel designs to improve VRB system efficiency

  7. Determination of plasma spot current and arc discharge plasma current on the system of plasma cathode electron sources using Rogowski coil technique

    International Nuclear Information System (INIS)

    Wirjoadi; Bambang Siswanto; Lely Susita RM; Agus Purwadi; Sudjatmoko

    2015-01-01

    It has been done the function test experiments of ignitor electrode system and the plasma generator electrode system to determine the current spot plasma and arc discharge plasma current with Rogowski coil technique. Ignitor electrode system that gets power supply from IDPS system can generate the plasma spot current of 11.68 ampere to the pulse width of about 33 μs, this value is greater than the design probably because of electronic components used in the IDPS system was not as planned. For the plasma generator electrode system that gets power from ADPS system capable of producing an arc discharge plasma current around 103.15 amperes with a pulse width of about 96 μs, and this value as planned. Based on the value of the arc discharge plasma current can be determined plasma electron density, which is about 10.12 10"1"9 electrons/m"3, and with this electron density value, an ignitor electrode system and a plasma generator system is quite good if used as a plasma cathode electron source system. (author)

  8. Currents, HF Radio-derived, Ano Nuevo, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  9. Currents, HF Radio-derived, Monterey Bay, Normal Model, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal model....

  10. Currents, HF Radio-derived, Monterey Bay, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  11. Currents, HF Radio-derived, Ano Nuevo, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  12. Currents, HF Radio-derived, Monterey Bay, Normal Model, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements, with missing values filled in by a normal...

  13. Currents, HF Radio-derived, SF Bay, 33 hr, Meridional, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 33 hour running average of the meridional component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  14. Currents, HF Radio-derived, SF Bay, 25 hr, Zonal, EXPERIMENTAL

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The data is the 25 hour running average of the zonal component of ocean surface currents derived from High Frequency Radio-derived measurements. THIS IS AN...

  15. Bivalve fouling of nuclear power plant service-water systems. Volume 2. Current status of biofouling surveillance and control techniques

    International Nuclear Information System (INIS)

    Daling, P.M.; Johnson, K.I.

    1985-03-01

    This report describes the current status of techniques for detection and control of cooling-water system fouling by bivalve mollusks at nuclear power plants. The effectiveness of these techniques is evaluated on the basis of information gathered from a literature review and in interviews with nuclear power plant personnel. Biofouling detection techniques examined in this report include regular maintenance, in-service inspection, and testing. Generally, these methods have been inadequate for detecting biofouling. Recommendations for improving biofouling detection capabilities are presented. Biofouling prevention (or control) methods that are examined in this report include intake screen systems, thermal treatment, preventive maintenance, chemical treatment alternatives, and antifoulant coatings. Recommendations for improving biofouling control methods at operating nuclear power plants are presented. Additional techniques that could be implemented at future power plants or that require further research are also described

  16. Surging Versus Continuous Turbidity Currents: Flow Dynamics and Deposits in an Experimental Intraslope Minibasin

    OpenAIRE

    Lamb, Michael P.; Hickson, Thomas; Marr, Jeffrey G.; Sheets, Ben; Paola, Chris; Parker, Gary

    2004-01-01

    Small intraslope basins (~100 km^2), or "minibasins," such as those found on the continental slope of the Gulf of Mexico, have been filled predominantly by turbidity currents. Each minibasin is the result of local subsidence and is partially or completely isolated from neighboring basins by ridges formed from compensational uplift. We undertook a series of experiments to investigate the relationship between the flow dynamics of turbidity currents entering a minibasin and the stratal architect...

  17. Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study

    OpenAIRE

    Santos,Michele Devido; Gagliardi,Rubens José; Mac-Kay,Ana Paula Machado Goyano; Boggio,Paulo Sergio; Lianza,Roberta; Fregni,Felipe

    2013-01-01

    CONTEXT AND OBJECTIVE: Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. DESIGN AND SETTING: Prospective cohort study developed in a public university hospital. METHODS: Nineteen patients with ...

  18. Experimental evaluation of IGBT junction temperature measurement via peak gate current

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Iannuzzo, Francesco

    2015-01-01

    Temperature sensitive electrical parameters allow junction temperature measurements on power semiconductors without modification to module packaging. The peak gate current has recently been proposed for IGBT junction temperature measurement and relies on the temperature dependent resistance...... of the gate pad. Consequently, a consideration of chip geometry and location of the gate pad is required before interpreting temperature data from this method. Results are also compared with a traditional electrical temperature measurement method: the voltage drop under low current....

  19. The role of ultrasound elastographic techniques in chronic liver disease: Current status and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Piscaglia, Fabio, E-mail: fabio.piscaglia@unibo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Marinelli, Sara, E-mail: sara_marinelli@libero.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Bota, Simona, E-mail: bota_simona1982@yahoo.com [Department of Gastroenterology and Hepatology, University of Medicine and Pharmacy “Victor Babeş”, Timişoara (Romania); Serra, Carla, E-mail: carla.serra@aosp.bo.it [Division of Medical Liver Transplant Care, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Venerandi, Laura, E-mail: laura.venerandi@gmail.com [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Leoni, Simona, E-mail: leonisimona@yahoo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy); Salvatore, Veronica, E-mail: veronica.salvatore@unibo.it [Division of Internal Medicine, University of Bologna, General and University Hospital S. Orsola-Malpighi, Bologna (Italy)

    2014-03-15

    This review illustrates the state of the art clinical applications and the future perspectives of ultrasound elastographic methods for the evaluation of chronic liver diseases, including the most widely used and validated technique, transient elastography, followed by shear wave elastography and strain imaging elastography. Liver ultrasound elastography allows the non-invasive evaluation of liver stiffness, providing information regarding the stage of fibrosis, comparable to liver biopsy which is still considered the gold standard; in this way, it can help physicians in managing patients, including the decision as to when to start antiviral treatment. The characterization of focal liver lesions and the prognostic role of the elastographic technique in the prediction of complications of cirrhosis are still under investigation.

  20. Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A

    International Nuclear Information System (INIS)

    Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

    1980-09-01

    The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort

  1. Shoulder arthroplasty in osteoarthritis: current concepts in biomechanics and surgical technique

    Science.gov (United States)

    Merolla, G; Nastrucci, G; Porcellini, G

    Shoulder arthroplasty is a technically demanding procedure to restore shoulder function in patients with severe osteoarthritis of the glenohumeral joint. The modern prosthetic system exploit the benefits of modularity and the availibility of additional sizes of the prosthetic components. In this paper we describe the biomechanics of shoulder arthroplasty and the technique for shoulder replacement including total shoulder arthroplasty (TSA) with all-polyethylene and metal-backed glenoid component, humeral head resurfacing and stemless humeral replacement. PMID:24251240

  2. Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

    1980-09-01

    The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.

  3. Current medical research with the application of coupled techniques with mass spectrometry

    OpenAIRE

    Ka?u?na-Czapli?ska, Joanna

    2011-01-01

    Summary The most effective methods of analysis of organic compounds in biological fluids are coupled chromatographic techniques. Capillary gas chromatography/mass spectrometry (GC-MS) allows the most efficient separation, identification and quantification of volatile metabolites in biological fluids. Liquid chromatography-mass spectrometry (LC-MS) is especially suitable for the analysis of non-volatile and/or thermally unstable compounds. A major drawback of liquid chromatography-mass spectro...

  4. Techniques for processing remote field eddy current signals from bend regions of steam generator tubes of prototype fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Thirunavukkarasu, S. [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India); Rao, B.P.C., E-mail: bpcrao@igcar.gov.in [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India); Jayakumar, T.; Raj, Baldev [Non Destructive Evaluation Division, Indira Gandhi Centre for Atomic Research, Kalpakkam, TN 603 102 (India)

    2011-04-15

    Steam generator (SG) is one of the most critical components of sodium cooled fast breeder reactor. Remote field eddy current (RFEC) technique has been chosen for in-service inspection (ISI) of these ferromagnetic SG tubes made of modified 9Cr-1Mo steel (Grade 91). Expansion bends are provided in the SGs to accommodate differential thermal expansion. During ISI using RFEC technique, in expansion bend regions, exciter-receiver coil misalignment, bending stresses, probe wobble and magnetic permeability variations produce disturbing noise hindering detection of defects. Fourier filtering, cross-correlation and wavelet transform techniques have been studied for noise reduction as well as enhancement of RFEC signals of defects in bend regions, having machined grooves and localized defects. Performance of these three techniques has been compared using signal-to-noise ratio (SNR). Fourier filtering technique has shown better performance for noise reduction while cross-correlation technique has resulted in significant enhancement of signals. Wavelet transform technique has shown the combined capability of noise reduction and signal enhancement and resulted in unambiguous detection of 10% of wall loss grooves and localized defects in the bend regions with SNR better than 7 dB.

  5. Are current coaching recommendations for cricket batting technique supported by biomechanical research?

    Science.gov (United States)

    Penn, Melissa J; Spratford, Wayne

    2012-09-01

    Coaching manuals are an invaluable tool for coaches, used in player skill and technique development, especially at grass-roots level. Commonly developed by former players and coaches, this information is generally based on anecdotal evidence and in general lacks the scientific rigour of a peer-reviewed journal. Thus there is a need to establish the level of agreement and support between the coaching and biomechanical literature. In doing so, evidence-based coaching practices can be optimally developed. Moreover, this will ensure the technique and skill development practices implemented at grass-roots level are supported by successful performance in the later stages of player development. The purpose of this review was to evaluate the latest batting biomechanics research, providing a comprehensive and up-to-date insight into the kinematic and kinetic aspects of batting in cricket. Furthermore, this review compared and contrasted this research with a selection of coaching literature, establishing a strong level of support and agreement between the coaching and biomechanical literature in recommendations for cricket batting technique. Although the ambiguity in a number of coaching concepts still exists, coaches and players can be confident in the successful implementation of both sources of information in a player's technical development.

  6. Endoscopic sutured gastroplasty: procedure evolution from first-in-man cases through current technique.

    Science.gov (United States)

    Kumar, Nitin; Abu Dayyeh, Barham K; Lopez-Nava Breviere, Gontrand; Galvao Neto, Manoel P; Sahdala, Nicole P; Shaikh, Sohail N; Hawes, Robert H; Gostout, Christopher J; Goenka, Mahesh K; Orillac, Jorge R; Alvarado, Alonso; Jirapinyo, Pichamol; Zundel, Natan; Thompson, Christopher C

    2018-04-01

    Endoscopic sutured gastroplasty (ESG) has evolved over time. With the advent of full-thickness endoscopic suturing, an efficient technique for ESG was developed and refined. This prospective first-in-man trial started in April 2012 and represents the first use of full-thickness endoscopic suturing for primary obesity therapy. The trial focused on procedure development, reproducibility, safety, and short-term efficacy. The trial was performed at centers in five countries, in three phases. Phase I was evaluation of safety and technical feasibility of various procedure techniques; stitch patterns and sequences were assessed for efficiency, safety, and feasibility. Phase II entailed continued procedure refinement to establish a standardized technique. Phase III entailed evaluation of technical feasibility and weight loss outcomes in 77 patients; the procedure was performed using the standardized technique, and there was no procedure development. Data were prospectively collected into a registry. In Phase I, the procedure was created and modified to improve time efficiency. Safety and technical feasibility were established, and short-term weight loss was demonstrated. In Phase II, a number of stitch patterns were attempted, and the stitch pattern was modified and finalized. 22 patients were included, and 1-year total weight loss was 17.3 ± 2.6%. In Phase III, conformity with the final technique was high. 77 patients were included, with a mean BMI of 36.1 ± 0.6 kg/m 2 . Mean weight loss was 16.0 ± 0.8% at 6 months and 17.4 ± 1.2% at 12 months (n = 44). Postprocedural nausea, vomiting, and epigastric pain were frequently reported; there were no reported significant adverse events post-procedure or during the follow-up period. Following a methodical procedure development phase, ESG demonstrated safety and short-term efficacy in this trial. The procedure also achieved meaningful weight loss during the follow-up period.

  7. The case for a directional dark matter detector and the status of current experimental efforts

    CERN Document Server

    Ahlen, S; Battat, J B R; Billard, J; Bozorgnia, N; Burgos, S; Caldwell, T; Carmona, J M; Cebrián, S; Colas, P; Dafni, T; Daw, E; Dujmic, D; Dushkin, A; Fedus, W; Ferrer, E; Finkbeiner, D; Fisher, P H; Forbes, J; Fusayasu, T; Galan, J; Gamble, T; Ghag, C; Giomataris, Yu; Gold, M; Gomez, H; Gómez, M E; Gondolo, P; Green, A; Grignon, C; Guillaudin, O; Hagemann, C; Hattori, K; Henderson, S; Higashi, N; Ida, C; Iguaz, F J; Inglis, A; Irastorza, I G; Iwaki, S; Kaboth, A; Kabuki, S; Kadyk, J; Kallivayalil, N; Kubo, H; Kurosawa, S; Kudryavtsev, V A; Lamy, T; Lanza, R; Lawson, T B; Lee, A; Lee, E R; Lin, T; Loomba, D; López, J; Luzón, G; Manobu, T; Martoff, J; Mayet, F; McCluskey, B; Miller, E; Miuchi, K; Monroe, J; Morgan, B; Muna, D; Murphy, A St J; Naka, T; Nakamura, K; Nakamura, M; Nakano, T; Nicklin, G G; Nishimura, H; Niwa, K; Paling, S M; Parker, J; Petkov, A; Pipe, M; Pushkin, K; Robinson, M; Rodríguez, A; Rodríguez-Quintero, J; Sahin, T; Sanderson, R; Sanghi, N; Santos, D; Sato, O; Sawano, T; Sciolla, G; Sekiya, H; Slatyer, T R; Snowden-Ifft, D P; Spooner, N J C; Sugiyama, A; Takada, A; Takahashi, M; Takeda, A; Tanimori, T; Taniue, K; Tomas, A; Tomita, H; Tsuchiya, K; Turk, J; Tziaferi, E; Ueno, K; Vahsen, S; Vanderspek, R; Vergados, J; Villar, J A; Wellenstein, H; Wolfe, I; Yamamoto, R K; Yegoryan, H

    2010-01-01

    We present the case for a dark matter detector with directional sensitivity. This document was developed at the 2009 CYGNUS workshop on directional dark matter detection, and contains contributions from theorists and experimental groups in the field. We describe the need for a dark matter detector with directional sensitivity; each directional dark matter experiment presents their project's status; and we close with a feasibility study for scaling up to a one ton directional detector, which would cost around $150M.

  8. An In-Rush Current Suppression Technique for the Solid-State Transfer Switch System

    Science.gov (United States)

    Cheng, Po-Tai; Chen, Yu-Hsing

    More and more utility companies provide dual power feeders as a premier service of high power quality and reliability. To take advantage of this, the solid-state transfer switch (STS) is adopted to protect the sensitive load against the voltage sag. However, the fast transfer process may cause in-rush current on the load-side transformer due to the resulting DC-offset in its magnetic flux as the load-transfer is completed. The in-rush current can reach 2∼6 p.u. and it may trigger the over-current protections on the power feeder. This paper develops a flux estimation scheme and a thyristor gating scheme based on the impulse commutation bridge STS (ICBSTS) to minimize the DC-offset on the magnetic flux. By sensing the line voltages of both feeders, the flux estimator can predict the peak transient flux linkage at the moment of load-transfer and evaluate a suitable moment for the transfer to minimize the in-rush current. Laboratory test results are presented to validate the performance of the proposed system.

  9. Current Research in Resistivity Inversion Techniques by the Lab. Of Exploration Geophysics in Thessaloniki, Greece

    International Nuclear Information System (INIS)

    Tsokas, G.N.; Tsourlos, P.

    2007-01-01

    The current research in various topics of ERT methods is described. The main directions of this research have been imposed by exploration problems met in practice. Therefore, it is aimed towards the construction of reliable, accurate and easy to apply procedures and algorithms

  10. Experimental and analytical investigation on metal damage suffered from simulated lightning currents

    Science.gov (United States)

    Yakun, LIU; Zhengcai, FU; Quanzhen, LIU; Baoquan, LIU; Anirban, GUHA

    2017-12-01

    The damage of two typical metal materials, Al alloy 3003 and steel alloy Q235B, subjected to four representative lightning current components are investigated by laboratory and analytical studies to provide fundamental data for lightning protection. The four lightning components simulating the natural lightning consist of the first return stroke, the continuing current of interval stroke, the long continuing current, and the subsequent stroke, with amplitudes 200 kA, 8 kA, 400 A, and 100 kA, respectively. The damage depth and area suffered from different lightning components are measured by the ultrasonic scanning system. And the temperature rise is measured by the thermal imaging camera. The results show that, for both Al 3003 and steel Q235B, the first return stroke component results in the largest damage area with damage depth 0.02 mm uttermost. The long continuing current component leads to the deepest damage depth of 3.3 mm for Al 3003 and much higher temperature rise than other components. The correlation analysis between damage results and lightning parameters indicates that the damage depth has a positive correlation with charge transfer. The damage area is mainly determined by the current amplitude and the temperature rise increases linearly with the charge transfer larger.

  11. Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study

    Directory of Open Access Journals (Sweden)

    Michele Devido Santos

    Full Text Available CONTEXT AND OBJECTIVE: Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. DESIGN AND SETTING: Prospective cohort study developed in a public university hospital. METHODS: Nineteen patients with chronic aphasia received 10 transcranial direct current stimulation sessions lasting 20 minutes each on consecutive days, using a current of 2 mA. The anode was positioned over the supraorbital area and the cathode over the contralateral motor cortex. The following variables were analyzed before and after the 10 neuromodulation sessions: oral language comprehension, copying, dictation, reading, writing, naming and verbal fluency. RESULTS: There were no adverse effects in the study. We found statistically significant differences from before to after stimulation in relation to simple sentence comprehension (P = 0.034, naming (P = 0.041 and verbal fluency for names of animals (P = 0.038. Improved scores for performing these three tasks were seen after stimulation. CONCLUSIONS: We observed that excitability of the primary motor cortex through transcranial direct current stimulation was associated with effects on different aspects of language. This can contribute towards future testing in randomized controlled trials.

  12. Transcranial direct-current stimulation induced in stroke patients with aphasia: a prospective experimental cohort study.

    Science.gov (United States)

    Santos, Michele Devido; Gagliardi, Rubens José; Mac-Kay, Ana Paula Machado Goyano; Boggio, Paulo Sergio; Lianza, Roberta; Fregni, Felipe

    2013-01-01

    Previous animal and human studies have shown that transcranial direct current stimulation can induce significant and lasting neuroplasticity and may improve language recovery in patients with aphasia. The objective of the study was to describe a cohort of patients with aphasia after stroke who were treated with transcranial direct current stimulation. Prospective cohort study developed in a public university hospital. Nineteen patients with chronic aphasia received 10 transcranial direct current stimulation sessions lasting 20 minutes each on consecutive days, using a current of 2 mA. The anode was positioned over the supraorbital area and the cathode over the contralateral motor cortex. The following variables were analyzed before and after the 10 neuromodulation sessions: oral language comprehension, copying, dictation, reading, writing, naming and verbal fluency. There were no adverse effects in the study. We found statistically significant differences from before to after stimulation in relation to simple sentence comprehension (P = 0.034), naming (P = 0.041) and verbal fluency for names of animals (P = 0.038). Improved scores for performing these three tasks were seen after stimulation. We observed that excitability of the primary motor cortex through transcranial direct current stimulation was associated with effects on different aspects of language. This can contribute towards future testing in randomized controlled trials.

  13. An experimental study of particle-driven gravity currents on steep slopes with entrainment of particles

    Directory of Open Access Journals (Sweden)

    M. Rastello

    2002-01-01

    Full Text Available Results of laboratory experiments are presented in which a finite suspension of sawdust particles was released instantaneously into a rectangular channel immersed in a water tank. Two kinds of gravity currents were studied: currents with or without entrainment of particles from the bed. Experiments were repeated for two slopes: 30° and 45°. We observed that the velocity of the front was significantly in-creased as particle entrainment occurred. In addition, our experiments showed that the front kept a quasi-constant velocity for both runs. This might suggest that the flow regime corresponded to the "slumping regime" or "adjustment phase" described earlier by Huppert and Simpson (1980.

  14. Experimental study of collective effects in BEP storage ring with high stored current

    International Nuclear Information System (INIS)

    Danilov, V.; Koop, I.; Lysenko, A.; Militsyn, B.; Nesterenko, I.; Perevedentsev, E.; Pozdeev, E.; Ptitsin, V.; Shatunov, Yu.; Vasserman, I.

    1993-01-01

    The results of extensive investigation of beam dynamics with high current in BEP booster are presented. Strong bunch lengthening due to the potential well distortion by the inductive impedance was observed on the background of the multiple intrabeam scattering and of the ion accumulation (in the e - beam). The octupole and sextupole corrections enabled control of collective damping of the head-tail modes. Fast damping is also observed at zero chromaticity, this is attributed to the injection kickers acting as transmission lines. The proper tuning of the nonlinearity corrections cures the transverse instabilities and enables capability to store up to 0.8A current in a single bunch

  15. Guidance for Evaluating the Safety of Experimental Releases of Mosquitoes, Emphasizing Mark-Release-Recapture Techniques.

    Science.gov (United States)

    Benedict, Mark Q; Charlwood, J Derek; Harrington, Laura C; Lounibos, L Philip; Reisen, William K; Tabachnick, Walter J

    2018-01-01

    Experimental releases of mosquitoes are performed to understand characteristics of populations related to the biology, ability to transmit pathogens, and ultimately their control. In this article, we discuss considerations related to the safety of experimental releases of living mosquitoes, applying principles of good practice in vector biology that protect human health and comfort. We describe specific factors of experimental releases of mosquitoes that we believe are critical to inform institutional biosafety committees and similar review boards to which proposals to conduct mosquito release experiments have been submitted. In this study, "experimental releases" means those that do not significantly increase vector capacity or nuisance biting relative to the unperturbed natural baseline. This document specifically does not address releases of mosquitoes for ongoing control programs or trials of new control methods for which broader assessments of risk are required. It also does not address releases of transgenic or exotic (non-native) mosquito species, both of which require particular regulatory approval. Experimental releases may include females and males and evaluation must consider their effects based on the number released, their genotype and phenotype, the environment into which they are released, and postrelease collection activities. We consider whether increases of disease transmission and nuisance biting might result from proposed experimental releases against the backdrop of natural population size variation. We recommend that experimental releases be conducted in a manner that can be reasonably argued to have insignificant negative effects. Reviewers of proposals for experimental releases should expect applicants to provide such an argument based on evidence from similar studies and their planned activities. This document provides guidance for creating and evaluating such proposals.

  16. Reactivity change measurements on plutonium-uranium fuel elements in hector experimental techniques and results

    International Nuclear Information System (INIS)

    Tattersall, R.B.; Small, V.G.; MacBean, I.J.; Howe, W.D.

    1964-08-01

    The techniques used in making reactivity change measurements on HECTOR are described and discussed. Pile period measurements were used in the majority of oases, though the pile oscillator technique was used occasionally. These two methods are compared. Flux determinations were made in the vicinity of the fuel element samples using manganese foils, and the techniques used are described and an error assessment made. Results of both reactivity change and flux measurements on 1.2 in. diameter uranium and plutonium-uranium alloy fuel elements are presented, these measurements being carried out in a variety of graphite moderated lattices at temperatures up to 450 deg. C. (author)

  17. Detection of wall thinning of carbon steel pipe covered with insulation using Pulsed Eddy Current technique

    International Nuclear Information System (INIS)

    Park, Duckgun; Kishore, M. B.; Lee, D. H.

    2013-01-01

    The test sample is a ferromagnetic carbon steel pipe having different thickness, covered with a 10 cm plastic insulation laminated by 0.4 mm Al plate to simulate the pipelines in NPPs. The PEC Probe used for the wall thinning detection consists of an excitation coil and a Hall sensor. The excitation coils in the probe is driven by a rectangular bipolar current pulse and the Hall-sensor will detects the resultant field. The Hall sensor output is considered as PEC signal. Results shows that the PEC system can detect wall thinning in an insulated pipeline of the NPPs. Local wall thinning in pipelines affects the structural integrity of industries like nuclear power plants (NPPs). In the present study a pulsed eddy current (PEC) technology to detect the wall thing of carbon steel pipe covered with insulation is developed

  18. Evaluation of Resonant Damping Techniques for Z-Source Current-Type Inverter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Loh, Poh Chiang; Gajanayake, C.J.

    2008-01-01

    For the renewable energy sources whose outputs vary continuously, a Z-source current-type inverter has been proposed as a possible buck-boost alternative for grid-interfacing. With a unique X-shaped LC network connected between its dc power source and inverter topology, Z-source current......-type inverter is however expected to suffer from compounded resonant complications in addition to those associated with its second-order output filter. To improve its damping performance, this paper proposes the careful integration of Posicast or three-step compensators before the inverter pulse-width modulator...... for damping triggered resonant oscillations. In total, two compensators are needed for wave-shaping the inverter boost factor and modulation ratio, and they can conveniently be implemented using first-in first-out stacks and embedded timers of modern digital signal processors widely used in motion control...

  19. Innovations in surgery simulation: a review of past, current and future techniques

    OpenAIRE

    Badash, Ido; Burtt, Karen; Solorzano, Carlos A.; Carey, Joseph N.

    2016-01-01

    As a result of recent work-hours limitations and concerns for patient safety, innovations in extraclinical surgical simulation have become a desired part of residency education. Current simulation models, including cadaveric, animal, bench-top, virtual reality (VR) and robotic simulators are increasingly used in surgical training programs. Advances in telesurgery, three-dimensional (3D) printing, and the incorporation of patient-specific anatomy are paving the way for simulators to become int...

  20. Experimental Investigation on Electric Current-Aided Laser Stake Welding of Aluminum Alloy T-Joints

    Directory of Open Access Journals (Sweden)

    Xinge Zhang

    2017-11-01

    Full Text Available In the present study, aluminum alloy T-joints were welded using the laser stake-welding process. In order to improve the welding quality of the T-joints, an external electric current was used to aid the laser stake-welding process. The effects of the process parameters on the weld morphology, mechanical properties, and microstructure of the welded joints were analyzed and discussed in detail. The results indicate that the aided electric current should be no greater than a certain maximum value. Upon increasing the aided electric current, the weld width at the skin and stringer faying surface obviously increased, but there was an insignificant change in the penetration depth. Furthermore, the electric current and pressing force should be chosen to produce an expected weld width at the faying surface, whereas the laser power and welding speed should be primarily considered to obtain an optimal penetration depth. The tensile shear specimens failed across the faying surface or failed in the weld zone of the skin. The specimens that failed in the weld of the skin could resist a higher tensile shear load compared with specimens that failed across the faying surface. The microstructural observations and microhardness results demonstrated that the tensile shear load capacity of the aluminum alloy welded T-joint was mainly determined by the weld width at the faying surface.

  1. Experimental Study on the Influence of AC Stray Current on the Cathodic Protection of Buried Pipe

    Directory of Open Access Journals (Sweden)

    Qingmiao Ding

    2016-01-01

    Full Text Available The size of the damaged area of the coating and its position on the pipeline impacted the cathodic protection potential, and there was a damaged area of the greatest impact value. When damaged area was 300 mm2, the IR drop was the largest, and this situation could easily lead to inadequate protection; when the parallel spacing between pipeline and interference source was unchanged, the measured value curves of cathodic protection potential presented “U” shaped trend with the increasing stray current interference intensity. Under certain parallel spacing between pipeline and interference source, high alternating stray current intensity would cause serious negative offsets, so that the overprotection of the pipeline occurred, and make the coating crack; there was a parallel threshold length. When less than the threshold, the pipe-ground potential increases rapidly with the parallel length increasing. In order to judge whether a pipeline was interference by AC stray current and the risk of stray current corrosion, we should make a comprehensive analysis of the cathodic protection energizing potential, the switch-off potential, AC pipe-soil potential, IR drops, and so on.

  2. Experimental results of current distribution in Rutherford-type LHC cables

    CERN Document Server

    Verweij, A P

    2000-01-01

    Current distribution among the wires of multi-strand superconducting cables is an important item for accelerator magnets. A non-uniform distribution could cause additional field distortions in the magnet bore and can as well be one of the reasons of premature quenching. Since two years electrical measurements on superconducting Rutherford-type cables are performed at CERN as part of the reception tests for the Large Hadron Collider (LHC). Cable samples of 2.4 m length are tested at currents up to 32 kA, temperatures around 1.9 and 4.3 K, and fields up to 10 T, applied perpendicularly as well as parallel to the broad face of the cable. Last year, an array of 24 Hall probes was installed in the test set-up in order to measure the self-field of the cable samples along one cable pitch. Each of the probes measures the local field generated by the current in the strands close by, and the results of the all probes reflect therefore the distribution of the strand currents. Experiments are done varying the applied fie...

  3. Experimental Study of Thermoelectric Generator as Electrical Source of Impressed Current Cathodic Protection for Ship Hull

    Directory of Open Access Journals (Sweden)

    Adi Kurniawan

    2017-06-01

    Full Text Available Impressed Current Cathodic Protection (ICCP is a method to protect metallic material such as ship hull from corrosion by using electric current. In this research, a prototype of thermoelectric generator is developed in order to supply the ICCP system. This thermoelectric generator is planned to utilize the exhaust gas from main engine of the ship. Method carried in this research is assembling the prototype of thermoelectric generator followed by conducted experiment to observe the potential energy of the prototype. After that, the required number of thermoelectric generator is calculated to supply the ICCP system to protect the ship from corrosion. The object in this research is live fish carrier “Wellboat” which has 396.08 m2 wetted area. The required voltage and current to protect the ship from corrosion for three years are 16.67 Volt and 2.66 Ampere. Based on the experiment, a prototype of thermoelectric generator can generate 0.34 Ampere and 4.43 Volt, causing the need of 8 series and 4 parallels connection. It can be concluded that the corrosion rate on the ship hull can be decelerated by using impressed current cathodic protection method without needing additional cost or fuel consumption to produce electric energy.  

  4. Experimental and numerical study of influence of ferromagnetic cover on critical current of BiSCCO-2223/Ag tape superconductor

    International Nuclear Information System (INIS)

    Vojenciak, M; Souc, J; Goemoery, F

    2009-01-01

    Samples of commercially available BiSCCO-2223/Ag tape have been partially covered by the ferromagnetic material. Improvement of the self-field critical current up to 15 % has been achieved by this procedure. A critical current of such tape strongly depends on geometric and magnetic properties of both, the superconducting tape as well as the ferromagnetic cover. Numerical simulations, based on the critical state model using commercial finite element method (FEM) code, have been performed. Properties of superconductor are characterized by anisotropic dependence of the critical current density on magnetic field as well as detail geometry of filaments. The ferromagnetic material is characterized by nonlinear magnetization curve. Nonlinear dependences of the critical current on selected parameters are shown in this work. Optimization of the cover parameters using these curves has been made. Samples with various parameters have been manufactured for the confirmation of numerical simulations results. Experimental results are in good qualitative agreement with results obtained by numerical simulations.

  5. Korean national QPE technique development: Analysis of current QPE results and future plan

    Science.gov (United States)

    Cha, Joo Wan

    2013-04-01

    Korea Meteorological Administration(KMA) has developed a Real-time ADjusted Radar-AWS (Automatic Weather Station) Rainrate (RAD-RAR) system using eleven radars over the South Korea. The procedure of the RAD-RAR system in real time consists of four steps: 1) the quality control of volumetric reflectivity for each radar, 2) the computation of the every 10-min rain gauge rainfall within each radar, 3) the real time (10 min-updated) rainfall estimation by the Z-R relationship minimizing the difference between the 1.5-km constant altitude plan precipitation indicator and rain gauge rainfall based on Window Probability Matching Method(WPMM) and by the real-time bias correction of RAD-RAR conducted at every 10 minutes for each radar by making the bias, and 4) the composition of the 11-radar estimated rainfall data. In addition, a local gauge correction method applies for RAD-RAR system. Therefore, the correlation coefficient of R2 = 0.81 is obtained between the daily accumulated observed and RAD-RAR estimated rainfall in 2012. We like to develop a new QPE system using the multi-sensor(radar, rain gauge, numerical model output, and lightning) data for newly improving Korean national QPE system. We made the prototype QPE system in 2012 and improve the detail techniques now. In the future, the new high performance QPE system will include a dual polarization radar observation technique for providing more accurate and valuable national QPE data

  6. MRI technique for the preoperative evaluation of deep infiltrating endometriosis: current status and protocol recommendation

    International Nuclear Information System (INIS)

    Schneider, C.; Oehmke, F.; Tinneberg, H.-R.; Krombach, G.A.

    2016-01-01

    Endometriosis is a common cause of chronic pelvic pain and infertility. It is defined as the occurrence of endometrial tissue outside the uterine cavity and can manifest as a peritoneal, ovarian or infiltrating form, the latter being referred to as deep infiltrating endometriosis (DIE). Surgery is essential in the treatment of DIE and depending on the severity of the disease, surgery can be difficult and extensive. Beside clinical examination and ultrasound, magnetic resonance imaging (MRI) has proven its value to provide useful information for planning surgery in patients with suspected DIE. To optimise the quality of MRI examinations, radiologists have to be familiar with the capabilities and also the limitations of this technique with respect to the assessment of DIE. MRI yields morphological information by using mainly T1- and T2-weighted sequences, but can also provide functional information by means of intravenous gadolinium, diffusion-weighted imaging or cine-MRI. In this article, these techniques and also adequate measures of patient preparation, which are indispensable for successful MRI imaging for the preoperative evaluation of DIE, are reviewed and a comprehensive protocol recommendation is provided.

  7. Current applications of miniaturized chromatographic and electrophoretic techniques in drug analysis.

    Science.gov (United States)

    Aturki, Zeineb; Rocco, Anna; Rocchi, Silvia; Fanali, Salvatore

    2014-12-01

    In the last decade, miniaturized separation techniques have become greatly popular in pharmaceutical analysis. Miniaturized separation methods are increasingly utilized in all processes of drug discovery as well as quality control of pharmaceutical preparation. The great advantages presented by the analytical miniaturized techniques, including high separation efficiency and resolution, rapid analysis and minimal consumption of reagents and samples, make them an attractive alternative to the conventional chromatographic methods for drug analysis. The purpose of this review is to give a general overview of the applicability of capillary electrophoresis (CE), capillary electrochromatography (CEC) and micro/capillary/nano-liquid chromatography (micro-LC/CLC/nano-LC) for the analysis of pharmaceutical formulations, active pharmaceutical ingredients (API), drug impurity testing, chiral drug separation, determination of drugs and metabolites in biological fluids. The results concerning the use of CEC, micro-LC, CLC, and nano-LC in the period 2009-2013, while for CE, those from 2012 up to the review draft are here summarized and some specific examples are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Experimental study of current loss and plasma formation in the Z machine post-hole convolute

    Directory of Open Access Journals (Sweden)

    M. R. Gomez

    2017-01-01

    Full Text Available The Z pulsed-power generator at Sandia National Laboratories drives high energy density physics experiments with load currents of up to 26 MA. Z utilizes a double post-hole convolute to combine the current from four parallel magnetically insulated transmission lines into a single transmission line just upstream of the load. Current loss is observed in most experiments and is traditionally attributed to inefficient convolute performance. The apparent loss current varies substantially for z-pinch loads with different inductance histories; however, a similar convolute impedance history is observed for all load types. This paper details direct spectroscopic measurements of plasma density, temperature, and apparent and actual plasma closure velocities within the convolute. Spectral measurements indicate a correlation between impedance collapse and plasma formation in the convolute. Absorption features in the spectra show the convolute plasma consists primarily of hydrogen, which likely forms from desorbed electrode contaminant species such as H_{2}O, H_{2}, and hydrocarbons. Plasma densities increase from 1×10^{16}  cm^{−3} (level of detectability just before peak current to over 1×10^{17}  cm^{−3} at stagnation (tens of ns later. The density seems to be highest near the cathode surface, with an apparent cathode to anode plasma velocity in the range of 35–50  cm/μs. Similar plasma conditions and convolute impedance histories are observed in experiments with high and low losses, suggesting that losses are driven largely by load dynamics, which determine the voltage on the convolute.

  9. Simulation and experimental tests of a real-time DPWM technique ...

    African Journals Online (AJOL)

    This control strategy is a simple and an easy technique generating the same switching ..... Inverter”, Energy Conversion Congress and Exposition (ECCE ), IEEE, ... Minimize the Switching Loss”, Innovative Smart Grid Technologies (ISGT Asia), ...

  10. Experimental methods and modeling techniques for description of cell population heterogeneity

    DEFF Research Database (Denmark)

    Lencastre Fernandes, Rita; Nierychlo, M.; Lundin, L.

    2011-01-01

    With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between environmen......With the continuous development, in the last decades, of analytical techniques providing complex information at single cell level, the study of cell heterogeneity has been the focus of several research projects within analytical biotechnology. Nonetheless, the complex interplay between...

  11. Measurement of Mixing Rate between Fuel Subchannels: Development of a new Experimental Technique

    International Nuclear Information System (INIS)

    Silin, Nicolas; Barbero, Jose; Bubach, Ernesto; Juanico, Luis

    2000-01-01

    A superficial heater of nickel applied over a ceramic substrate was designed and constructed, together with a system of high sensitivity to measure temperature differentials. The use of both techniques was evaluated and it might allow for the wider use of the method of differential thermal analysis to quantify the turbulent mixing between coupled hydraulic subchannels in fuel elements. Even more, the method presents important advantages as compared to the more complicated techniques known (laser Doppler anemometry)

  12. The Shock and Vibration Bulletin. Part 4. Prediction and Experimental Techniques, Isolation and Damping

    Science.gov (United States)

    1973-06-01

    D. 0. Smallwood , Sandia Laboratories, Albuquerque, New Mexico and A. F. Witte, Kaman Sciences, Colorado Springs, Colorado fi TRANSIENT VIBRATION...TEST TECHNIQUE USING LEAST FAVORABLE RESPONSES D. O. Smallwood , Sandia Laboratories, Albuquerque, New Mexico PAPERS APPEARING IN PART 2 Structural...Dynamic Systems, Measure- ments and Control, March 1971. 12. Favour, John D., Maclom C. Mitchell, and Norman L. Olson, "Transient Test Techniques for

  13. Current Techniques of Growing Algae Using Flue Gas from Exhaust Gas Industry: a Review.

    Science.gov (United States)

    Huang, Guanhua; Chen, Feng; Kuang, Yali; He, Huan; Qin, An

    2016-03-01

    The soaring increase of flue gas emission had caused global warming, environmental pollution as well as climate change. Widespread concern on reduction of flue gas released from industrial plants had considered the microalgae as excellent biological materials for recycling the carbon dioxide directly emitted from exhaust industries. Microalgae also have the potential to be the valuable feedback for renewable energy production due to their high growth rate and abilities to sequester inorganic carbon through photosynthetic process. In this review article, we will illustrate important relative mechanisms in the metabolic processes of biofixation by microalgae and their recent experimental researches and advances of sequestration of carbon dioxide by microalgae on actual industrial and stimulate flue gases, novel photobioreactor cultivation systems as well as the perspectives and limitations of microalgal cultivation in further development.

  14. Experimental investigation of flooding in air-water counter-current flow with a vertical adiabatic multi-rod bundle

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Kim, Hho Jung; Cha, Jong Hee; Cho, Sung Jae; Chun, Moon Hyun

    1991-01-01

    The process of flooding phenomenon in a vertical adiabatic 3 x 3 tube bundle flow channel has been studied experimentally. A series of tests was performed, using three types of tube bundle differing only in the number of spacer grids attached, to investigate the effects of spacer grids and multi-flow channel interactions on the air-water counter-current flow limitations. Experimentally determined flooding points at various water film Reynolds numbers for three different test sections are presented in graphical form and compared with entrainment criterion for co-current flow and instability criteria. In addition, empirical flooding correlations of the Kutateladze type are obtained for each type of test section using liquid penetration data

  15. Glazed clay pottery and lead exposure in Mexico: Current experimental evidence.

    Science.gov (United States)

    Diaz-Ruiz, Araceli; Tristán-López, Luis Antonio; Medrano-Gómez, Karen Itzel; Torres-Domínguez, Juan Alejandro; Ríos, Camilo; Montes, Sergio

    2017-11-01

    Lead exposure remains a significant environmental problem; lead is neurotoxic, especially in developing humans. In Mexico, lead in human blood is still a concern. Historically, much of the lead exposure is attributed to the use of handcrafted clay pottery for cooking, storing and serving food. However, experimental cause-and-effect demonstration is lacking. The present study explores this issue with a prospective experimental approach. We used handcrafted clay containers to prepare and store lemonade, which was supplied as drinking water to pregnant rats throughout the gestational period. We found that clay pots, jars, and mugs leached on average 200 µg/l lead, and exposure to the lemonade resulted in 2.5 µg/dl of lead in the pregnant rats' blood. Neonates also showed increased lead content in the hippocampus and cerebellum. Caspase-3 activity was found to be statistically increased in the hippocampus in prenatally exposed neonates, suggesting increased apoptosis in that brain region. Glazed ceramics are still an important source of lead exposure in Mexico, and our results confirm that pregnancy is a vulnerable period for brain development.

  16. The fetal programming of food preferences: current clinical and experimental evidence.

    Science.gov (United States)

    Dalle Molle, R; Bischoff, A R; Portella, A K; Silveira, P P

    2015-09-28

    Increased energy consumption is one of the major factors implicated in the epidemic of obesity. There is compelling evidence, both clinical and experimental, that fetal paucity of nutrients may have programming effects on feeding preferences and behaviors that can contribute to the development of diseases. Clinical studies in different age groups show that individuals born small for their gestational age (SGA) have preferences towards highly caloric foods such as carbohydrates and fats. Some studies have also shown altered eating behaviors in SGA children. Despite an apparent discrepancy in different age groups, all studies seem to converge to an increased intake of palatable foods in SGA individuals. Small nutrient imbalances across lifespan increase the risk of noncommunicable diseases in adult life. Homeostatic factors such as altered responses to leptin and insulin and alterations in neuropeptides associated with appetite and satiety are likely involved. Imbalances between homeostatic and hedonic signaling are another proposed mechanism, with the mesocorticolimbic dopaminergic pathway having differential reward and pleasure responses when facing palatable foods. Early exposure to undernutrition also programs hypothalamic-pituitary-adrenal axis, with SGA having higher levels of cortisol in different ages, leading to chronic hyperactivity of this neuroendocrine axis. This review summarizes the clinical and experimental evidence related to fetal programming of feeding preferences by SGA.

  17. Experimental study of natural two-phase flow circulation using a visualization technique; Estudo experimental da circulacao natural bifasica utilizando uma tecnica de visualizacao

    Energy Technology Data Exchange (ETDEWEB)

    Vinhas, Pedro A.M., E-mail: Pedro_mvinhas@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Nuclear; Faccini, Jose L.H., E-mail: faccini@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Su, Jian, E-mail: sujian@lasme.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear

    2013-07-01

    This paper presents an experimental study of natural two-phase flow in a circuit that simulates, on a smaller scale, a typical residual heat removal system of passive reactors APWR (Advanced Pressurized Water Reactor). The circuit was formed by a heater, a heat exchanger and piping. The experimental study was the application of a visualization technique, using a high speed camera, for measuring the size and speed of vapor bubbles generated in the heater with different power heating. The camera was positioned in the central region of the pipe connecting the heater to the heat exchanger, where there is a clear passage. The flow of images were processed and analyzed using commercial software that allowed the determination of the length and velocity of the bubbles. The results were then compared with correlations available in literature.

  18. Protobacco Media Exposure and Youth Susceptibility to Smoking Cigarettes, Cigarette Experimentation, and Current Tobacco Use among US Youth.

    Directory of Open Access Journals (Sweden)

    Erika B Fulmer

    Full Text Available Youth are exposed to many types of protobacco influences, including smoking in movies, which has been shown to cause initiation. This study investigates associations between different channels of protobacco media and susceptibility to smoking cigarettes, cigarette experimentation, and current tobacco use among US middle and high school students.By using data from the 2012 National Youth Tobacco Survey, structural equation modeling was performed in 2013. The analyses examined exposure to tobacco use in different channels of protobacco media on smoking susceptibility, experimentation, and current tobacco use, accounting for perceived peer tobacco use.In 2012, 27.9% of respondents were never-smokers who reported being susceptible to trying cigarette smoking. Cigarette experimentation increased from 6.3% in 6th grade to 37.1% in 12th grade. Likewise, current tobacco use increased from 5.2% in 6th grade to 33.2% in 12th grade. Structural equation modeling supported a model in which current tobacco use is associated with exposure to static advertising through perception of peer use, and by exposure to tobacco use depicted on TV and in movies, both directly and through perception of peer use. Exposure to static advertising appears to directly increase smoking susceptibility but indirectly (through increased perceptions of peer use to increase cigarette experimentation. Models that explicitly incorporate peer use as a mediator can better discern the direct and indirect effects of exposure to static advertising on youth tobacco use initiation.These findings underscore the importance of reducing youth exposure to smoking in TV, movies, and static advertising.

  19. Experimental study on a wide range of wave and current conditions of the WEPTOS Wave Energy Converter

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter

    This report presents the results of an experimental study that was performed on small scale model that was a replication of the full-scale Weptos WEC intended for DanWEC. The tests were performed in the circular basin at FloWave at Edinburgh University in October 2014. The laboratory facilities h...... the capabilities to have simultaneously currents and waves from any possible direction and also to produce advanced wave specifications....

  20. Application of the failure modes and effects analysis technique to the emergency cooling system of an experimental nuclear power plant

    International Nuclear Information System (INIS)

    Conceicao Junior, Osmar; Silva, Antonio Teixeira e

    2009-01-01

    This study consists on the application of the failure modes and effects analysis (FMEA), a hazard identification and a risk assessment technique, to the emergency cooling system (ECS), of an experimental nuclear power plant. The choice of this technique was due to its detailed analysis of each component of the system, enabling the identification of all possible ways of failure and its related consequences (in order of importance), allowing the designer to improve the system, maximizing its security and reliability. Through the application of this methodology, it could be observed that the ECS is an intrinsically safe system, in spite of the modifications proposed. (author)

  1. Direct imaging of neural currents using ultra-low field magnetic resonance techniques

    Science.gov (United States)

    Volegov, Petr L [Los Alamos, NM; Matlashov, Andrei N [Los Alamos, NM; Mosher, John C [Los Alamos, NM; Espy, Michelle A [Los Alamos, NM; Kraus, Jr., Robert H.

    2009-08-11

    Using resonant interactions to directly and tomographically image neural activity in the human brain using magnetic resonance imaging (MRI) techniques at ultra-low field (ULF), the present inventors have established an approach that is sensitive to magnetic field distributions local to the spin population in cortex at the Larmor frequency of the measurement field. Because the Larmor frequency can be readily manipulated (through varying B.sub.m), one can also envision using ULF-DNI to image the frequency distribution of the local fields in cortex. Such information, taken together with simultaneous acquisition of MEG and ULF-NMR signals, enables non-invasive exploration of the correlation between local fields induced by neural activity in cortex and more `distant` measures of brain activity such as MEG and EEG.

  2. The edge transient-current technique (E-TCT) with high energy hadron beam

    Energy Technology Data Exchange (ETDEWEB)

    Gorišek, Andrej; Cindro, Vladimir; Kramberger, Gregor; Mandić, Igor [J. Stefan Institute, Ljubljana (Slovenia); Mikuž, Marko [J. Stefan Institute, Ljubljana (Slovenia); University of Ljubljana (Slovenia); Muškinja, Miha; Zavrtanik, Marko [J. Stefan Institute, Ljubljana (Slovenia)

    2016-09-21

    We propose a novel way to investigate the properties of silicon and CVD diamond detectors for High Energy Physics experiments complementary to the already well-established E-TCT technique using laser beam. In the proposed setup the beam of high energy hadrons (MIPs) is used instead of laser beam. MIPs incident on the detector in the direction parallel to the readout electrode plane and perpendicular to the edge of the detector. Such experiment could prove very useful to study CVD diamond detectors that are almost inaccessible for the E-TCT measurements with laser due to large band-gap as well as to verify and complement the E-TCT measurements of silicon. The method proposed is being tested at CERN in a beam of 120 GeV hadrons using a reference telescope with track resolution at the DUT of few μm. The preliminary results of the measurements are presented.

  3. A Generic Current Mode Design for Multifunction Grounded Capacitor Filters Employing Log-Domain Technique

    Directory of Open Access Journals (Sweden)

    N. A. Shah

    2011-01-01

    Full Text Available A generic design (GD for realizing an nth order log-domain multifunction filter (MFF, which can yield four possible stable filter configurations, each offering simultaneously lowpass (LP, highpass (HP, and bandpass (BP frequency responses, is presented. The features of these filters are very simple, consisting of merely a few exponential transconductor cells and capacitors; all grounded elements, capable of absorbing the shunt parasitic capacitances, responses are electronically tuneable, and suitable for monolithic integration. Furthermore, being designed using log-domain technique, it offers all its advantages. As an example, 5th-order MFFs are designed in each case and their performances are evaluated through simulation. Lastly, a comparative study of the MFFs is also carried, which helps in selecting better high-order MFF for a given application.

  4. Current and emerging techniques for contaminant mapping and data visualization at DNAPL sites

    DEFF Research Database (Denmark)

    Wealthall, Gary; Durant, Neal; Grosen, Bernt

    methods will be discussed in the context of contaminant delineation, remediation design, technology verification and regulatory acceptance. We present a range of site investigation tools, based on the principle of combined lines of evidence and the premise that a single technique is not available to fully......Recent advances in the development of contaminant specific site investigation tools has significantly enhanced our ability to characterize the spatial architecture of DNAPL source zones in both sedimentary and fractured bedrock environments. The application of innovative site characterization...... value. These methods are generally of lower cost, produce vertical profiles of real-time data and are primarily used to identify site areas that require further investigation. Examples of such "decision quality" methods are drive point tools, such as laser-induced fluorescence profiling and membrane...

  5. Breast reconstruction with anatomical implants: A review of indications and techniques based on current literature.

    Science.gov (United States)

    Gardani, Marco; Bertozzi, Nicolò; Grieco, Michele Pio; Pesce, Marianna; Simonacci, Francesco; Santi, PierLuigi; Raposio, Edoardo

    2017-09-01

    One important modality of breast cancer therapy is surgical treatment, which has become increasingly less mutilating over the last century. Breast reconstruction has become an integrated part of breast cancer treatment due to long-term psychosexual health factors and its importance for breast cancer survivors. Both autogenous tissue-based and implant-based reconstruction provides satisfactory reconstructive options due to better surgeon awareness of "the ideal breast size", although each has its own advantages and disadvantages. An overview of the current options in breast reconstruction is presented in this article.

  6. A review of post-modern management techniques as currently applied to Turkish forestry.

    Science.gov (United States)

    Dölarslan, Emre Sahin

    2009-01-01

    This paper reviews the effects of six post-modern management concepts as applied to Turkish forestry. Up to now, Turkish forestry has been constrained, both in terms of its operations and internal organization, by a highly bureaucratic system. The application of new thinking in forestry management, however, has recently resulted in new organizational and production concepts that promise to address problems specific to this Turkish industry and bring about positive changes. This paper will elucidate these specific issues and demonstrate how post-modern management thinking is influencing the administration and operational capacity of Turkish forestry within its current structure.

  7. Advanced computer techniques for inverse modeling of electric current in cardiac tissue

    Energy Technology Data Exchange (ETDEWEB)

    Hutchinson, S.A.; Romero, L.A.; Diegert, C.F.

    1996-08-01

    For many years, ECG`s and vector cardiograms have been the tools of choice for non-invasive diagnosis of cardiac conduction problems, such as found in reentrant tachycardia or Wolff-Parkinson-White (WPW) syndrome. Through skillful analysis of these skin-surface measurements of cardiac generated electric currents, a physician can deduce the general location of heart conduction irregularities. Using a combination of high-fidelity geometry modeling, advanced mathematical algorithms and massively parallel computing, Sandia`s approach would provide much more accurate information and thus allow the physician to pinpoint the source of an arrhythmia or abnormal conduction pathway.

  8. Sensitive technique for detecting outer defect on tube with remote field eddy current testing

    International Nuclear Information System (INIS)

    Kobayashi, Noriyasu; Nagai, Satoshi; Ochiai, Makoto; Jimbo, Noboru; Komai, Masafumi

    2008-01-01

    In the remote field eddy current testing, we proposed the method of enhancing the magnetic flux density in the vicinity of an exciter coil by controlling the magnetic flux direction for increasing the sensitivity of detecting outer defects on a tube and used the flux guide made of a magnetic material for the method. The optimum structural shape of the flux guide was designed by the magnetic field analysis. On the experiment with the application of the flux guide, the magnetic flux density increased by 59% and the artificial defect detection signal became clear. We confirmed the proposed method was effective in a high sensitivity. (author)

  9. Experimental design techniques in statistical practice a practical software-based approach

    CERN Document Server

    Gardiner, W P

    1998-01-01

    Provides an introduction to the diverse subject area of experimental design, with many practical and applicable exercises to help the reader understand, present and analyse the data. The pragmatic approach offers technical training for use of designs and teaches statistical and non-statistical skills in design and analysis of project studies throughout science and industry. Provides an introduction to the diverse subject area of experimental design and includes practical and applicable exercises to help understand, present and analyse the data Offers technical training for use of designs and teaches statistical and non-statistical skills in design and analysis of project studies throughout science and industry Discusses one-factor designs and blocking designs, factorial experimental designs, Taguchi methods and response surface methods, among other topics.

  10. Experimental determination of the thermal contact conductance between two solid surfaces by the energy pulse technique

    International Nuclear Information System (INIS)

    Rubin, Gerson Antonio

    1979-01-01

    An experimental procedure for the determination of the thermal contact conductance between two solid surfaces as a function of the contact pressure and the energy of the laser radiation has been developed using the laser pulse method. A rubi laser with variable energy levels was employed as a radiating pulse energy source. The laser beam was allowed to impinge perpendicularly on the front face of a electrolytic iron 73 4 . The temperature fluctuations resulting on the back surface of the sample was detected by a thermocouple, which Is coupled to a PDP-11/45 Computer 32 Kbytes of memory, through a Analog-Digital Converter. A theoretical function, derived exclusively for the problem mentioned in this work, was adjusted by a method of least square fitting of experimental results. This adjustment yielded the value of a parameter related to the contact conductance between two surfaces. The experimental error obtained for the thermal contact conductance was +- 4.9%. (author)

  11. Application of eddy current inversion technique to the sizing of defects in Inconel welds with rough surfaces

    International Nuclear Information System (INIS)

    Yusa, Noritaka; Machida, Eiji; Janousek, Ladislav; Rebican, Mihai; Chen, Zhenmao; Miya, Kenzo

    2005-01-01

    This paper evaluates the applicability of eddy current inversion techniques to the sizing of defects in Inconel welds with rough surfaces. For this purpose, a plate Inconel weld specimen, which models the welding of a stub tube in a boiling water nuclear reactor is fabricated, and artificial notches machined into the specimen. Eddy current inspections using six different eddy current probes are conducted and efficiencies were evaluated for the six probes for weld inspection. It is revealed that if suitable probes are applied, an Inconel weld does not cause large noise levels during eddy current inspections even though the surface of the weld is rough. Finally, reconstruction of the notches is performed using eddy current signals measured using the uniform eddy current probe that showed the best results among the six probes in this study. A simplified configuration is proposed in order to consider the complicated configuration of the welded specimen in numerical simulations. While reconstructed profiles of the notches are slightly larger than the true profiles, quite good agreements are obtained in spite of the simple approximation of the configuration, which reveals that eddy current testing would be an efficient non-destructive testing method for the sizing of defects in Inconel welds

  12. Experimental study on two-phase flow in horizontal duct using a visualization technique

    International Nuclear Information System (INIS)

    Oliveira, Livia A.; Tomas, Bruno T.; Cunha Filho, Jurandyr S.; Su, Jian

    2009-01-01

    In this paper an experimental study is performed for visualization of water-air two phase flow, stratified and intermittent, in a 51 mm internal diameter circular section horizontal tube. The study consists in filming a water-air mixture passin by a transparent interval of the tube, using a high speed camera. After that, the obtained images are analysed frame after frame and then, data are extracted of weight of gas-liquid interfaces, length and gas bubbles speeds. Then, these data are verified with experimental and theoretical correlations available in the literature

  13. Experimental testing and modelling of a resistive type superconducting fault current limiter using MgB2 wire

    International Nuclear Information System (INIS)

    Smith, A C; Pei, X; Oliver, A; Husband, M; Rindfleisch, M

    2012-01-01

    A prototype resistive superconducting fault current limiter (SFCL) was developed using single-strand round magnesium diboride (MgB 2 ) wire. The MgB 2 wire was wound with an interleaved arrangement to minimize coil inductance and provide adequate inter-turn voltage withstand capability. The temperature profile from 30 to 40 K and frequency profile from 10 to 100 Hz at 25 K were tested and reported. The quench properties of the prototype coil were tested using a high current test circuit. The fault current was limited by the prototype coil within the first quarter-cycle. The prototype coil demonstrated reliable and repeatable current limiting properties and was able to withstand a potential peak current of 372 A for one second without any degradation of performance. A three-strand SFCL coil was investigated and demonstrated scaled-up current capacity. An analytical model to predict the behaviour of the prototype single-strand SFCL coil was developed using an adiabatic boundary condition on the outer surface of the wire. The predicted fault current using the analytical model showed very good correlation with the experimental test results. The analytical model and a finite element thermal model were used to predict the temperature rise of the wire during a fault. (paper)

  14. Experimental Study on Damage Detection in Timber Specimens Based on an Electromechanical Impedance Technique and RMSD-Based Mahalanobis Distance

    Directory of Open Access Journals (Sweden)

    Dansheng Wang

    2016-10-01

    Full Text Available In the electromechanical impedance (EMI method, the PZT patch performs the functions of both sensor and exciter. Due to the high frequency actuation and non-model based characteristics, the EMI method can be utilized to detect incipient structural damage. In recent years EMI techniques have been widely applied to monitor the health status of concrete and steel materials, however, studies on application to timber are limited. This paper will explore the feasibility of using the EMI technique for damage detection in timber specimens. In addition, the conventional damage index, namely root mean square deviation (RMSD is employed to evaluate the level of damage. On that basis, a new damage index, Mahalanobis distance based on RMSD, is proposed to evaluate the damage severity of timber specimens. Experimental studies are implemented to detect notch and hole damage in the timber specimens. Experimental results verify the availability and robustness of the proposed damage index and its superiority over the RMSD indexes.

  15. Gut Microbiota in Multiple Sclerosis and Experimental Autoimmune Encephalomyelitis: Current Applications and Future Perspectives

    Science.gov (United States)

    Lang, Yue

    2018-01-01

    The gut environment and gut microbiome dysbiosis have been demonstrated to significantly influence a range of disorders in humans, including obesity, diabetes, rheumatoid arthritis, and multiple sclerosis (MS). MS is an autoimmune disease affecting the central nervous system (CNS). The etiology of MS is not clear, and it should involve both genetic and extrinsic factors. The extrinsic factors responsible for predisposition to MS remain elusive. Recent studies on MS and its animal model, experimental autoimmune encephalomyelitis (EAE), have found that gastrointestinal microbiota may play an important role in the pathogenesis of MS/EAE. Thus, gut microbiome adjustment may be a future direction of treatment in MS. In this review, we discuss the characteristics of the gut microbiota, the connection between the brain and the gut, and the changes in gut microbiota in MS/EAE, and we explore the possibility of applying microbiota therapies in patients with MS. PMID:29805314

  16. Experimental test of the PCAC-hypothesis in charged current neutrino and antineutrino interactions on protons

    Science.gov (United States)

    Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; O'Neale, S. W.; Klein, H.; Morrison, D. R. O.; Schmid, P.; Wachsmuth, H.; Miller, D. B.; Mobayyen, M. M.; Wainstein, S.; Aderholz, M.; Hoffmann, E.; Katz, U. F.; Kern, J.; Schmitz, N.; Wittek, W.; Allport, P.; Myatt, G.; Radojicic, D.; Bullock, F. W.; Burke, S.

    1987-03-01

    Data obtained with the bubble chamber BEBC at CERN are used for the first significant test of Adler's prediction for the neutrino and antineutrino-proton scattering cross sections at vanishing four-momentum transfer squared Q 2. An Extended Vector Meson Dominance Model (EVDM) is applied to extrapolate Adler's prediction to experimentally accessible values of Q 2. The data show good agreement with Adler's prediction for Q 2→0 thus confirming the PCAC hypothesis in the kinematical region of high leptonic energy transfer ν>2 GeV. The good agreement of the data with the theoretical predictions also at higher Q 2, where the EVDM terms are dominant, also supports this model. However, an EVDM calculation without PCAC is clearly ruled out by the data.

  17. Experimental test of the PCAC-hypothesis in charged current neutrino and antineutrino interactions on protons

    International Nuclear Information System (INIS)

    Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; O'Neale, S.W.; Klein, H.; Morrison, D.R.O.; Schmid, P.; Wachsmuth, H.; Allport, P.; Myatt, G.; Radojicic, D.; Bullock, F.W.; Burke, S.

    1987-01-01

    Data obtained with the bubble chamber BEBC at CERN are used for the first significant test of Adler's prediction for the neutrino and antineutrino-proton scattering cross sections at vanishing four-momentum transfer squared Q 2 . An Extended Vector Meson Dominance Model (EVDM) is applied to extrapolate Adler's prediction to experimentally accessible values of Q 2 . The data show good agreement with Adler's prediction for Q 2 → 0 thus confirming the PCAC hypothesis in the kinematical region of high leptonic energy transfer ν > 2 GeV. The good agreement of the data with the theoretical predictions also at higher Q 2 , where the EVDM terms are dominant, also supports this model. However, an EVDM calculation without PCAC is clearly ruled out by the data. (orig.)

  18. Current Status of Clinical and Experimental Researches on Cognitive Impairment in Diabetes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This article reviews the clinical and experimental researches on cognitive impairment related to diabetes in the recent decade. Most clinical studies indicate that the cognitive impairment in patients with type 1 diabetes mellitus is related to recurrent hypoglycemia closely. There is little research about whether or not hyperglycemia is related to cognitive impairment in patients with type 1 diabetes mellitus. Most studies indicate that the cognitive impairment in type 2 diabetes involves multiple factors through multiple mechanisms, including blood glucose, blood lipid, blood pressure, level of insulin, medication, chronic complication, etc. But, there has been no large-scale, multi-center, randomized controlled clinical trial in China recently. And what is more, some problems exist in this field of research, such as the lack of golden criterion of cognitive function measurement, different population of studied objects, and incomprehensive handling of confounding factors. Experimental studies found that hippocampal long-term potentiation (LTP) was impaired,which were manifested by impairment of spatial memory and decreased expression of LTP, but its relation to hyperglycemia, the duration of diabetes, learning and memory has always been differently reported by different researches. Thus, there are a lot of unknown things to be explored and studied in order to clarify its mechanism. TCM has abundant clinical experience in treating cerebral disease with medicine that enforces the kidney and promotes wit. However, there has been no research on treating diabetic cognitive impairment,which requires work to be done actively and TCM to be put into full play, in order to improve the treatment of diabetes and enhance living quality of patients.

  19. An experimental study on counter current flow limitation in annular narrow gaps with large diameter

    Energy Technology Data Exchange (ETDEWEB)

    Park, Rae Joon; Jeong, Ji Whan; Lee, Sung Jin; Cho, Young Ro; Ha, Kwang Sun; Kim, Sang Baik; Kim, Hee Dong [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2002-04-01

    The present study intends to carry out CCFL experiment with the same gap size as the CHFG facility and suggest an empirical correlation in order to provide basic information useful to development of an empirical critical-power correlation. The present facility consists of water accumulator tank, test section, DC pump, air regulator, valves and sensors. Air and water are used as working fluids. The experiments are carried out at the atmospheric pressure. Differential pressure between the gap ends, liquid and gas phase flow rates, temperature, lower plenum pressure are measured.Measured values are expressed in terms of Wallis' parameter using gap size as a characteristic length. There is a big difference between the present experimental results and the Koizumi et al.'s results, but the present experimental results are very similar to the Richter et al.'s results. The present results agree well with the Osakabe and Kawasaki's results. In comparison of present experiments with the Koizumi et al.'s experiments, gap thickness is similar, but the diameter of the present is bigger than that of Koizumi et al.'s experiments. In comparison of present experiments with the Richter et al.'s experiments, diameter is similar, but the gap thickness of the present is smaller than that of Richter et al.'s experiments. It is judged from these results that correlation development on CCFL to consider gap thickness is reasonable at similar condition of diameter.The developed correlation will be used to develop the CHFG model. 36 refs., 26 figs., 7 tabs. (Author)

  20. [Acoustic emission diagnostic techniques for high-field high current-density super inducting poles

    International Nuclear Information System (INIS)

    1990-01-01

    Acoustic emission technology was introduced in the late 1970's to monitor superconducting magnets. It has now been firmly established that acoustic signals in superconducting magnets are emitted principally by mechanical events such as conductor strain, conductor motion, frictional motion, and epoxy cracking. Despite earlier suggestions, flux motion, except during flux jumping, does not appear to be an important source of AE signals in superconducting magnets. Of these several potential sources of AE signals in superconducting magnets, mechanical disturbances have been identified to be most important in high-performance, ''adiabatic'' magnets such as the dipoles used in accelerators. These mechanical disturbances are transitory, each generating a packet of AE signals that can be located with sensors. Source identification and location has been achieved with a number of superconducting magnets. In this section, the basic principle for the operation of adiabatic magnets is discussed, followed by presentation of some of the important experimental results relevant to the question of premature quench obtained at MIT

  1. A Readout Integrated Circuit (ROIC) employing self-adaptive background current compensation technique for Infrared Focal Plane Array (IRFPA)

    Science.gov (United States)

    Zhou, Tong; Zhao, Jian; He, Yong; Jiang, Bo; Su, Yan

    2018-05-01

    A novel self-adaptive background current compensation circuit applied to infrared focal plane array is proposed in this paper, which can compensate the background current generated in different conditions. Designed double-threshold detection strategy is to estimate and eliminate the background currents, which could significantly reduce the hardware overhead and improve the uniformity among different pixels. In addition, the circuit is well compatible to various categories of infrared thermo-sensitive materials. The testing results of a 4 × 4 experimental chip showed that the proposed circuit achieves high precision, wide application and high intelligence. Tape-out of the 320 × 240 readout circuit, as well as the bonding, encapsulation and imaging verification of uncooled infrared focal plane array, have also been completed.

  2. Nondestructive examination of irradiated fuel rods by pulsed eddy current techniques

    International Nuclear Information System (INIS)

    Francis, W.C.; Quapp, W.J.; Martin, M.R.; Gibson, G.W.

    1976-02-01

    A number of fuel rods and unfueled zircaloy cladding tubes which had been irradiated in the Saxton reactor have undergone extensive nondestructive and corroborative destructive examinations by Aerojet Nuclear Company as part of the Water Reactor Safety Research Program, Irradiation Effects Test Series. This report discusses the pulsed eddy current (PEC) nondestructive examinations on the fuel rods and tubing and the metallography results on two fuel rods and one irradiated zircaloy tube. The PEC equipment, designed jointly by Argonne National Laboratory and Aerojet, performed very satisfactorily the functions of diameter, profile, and wall thickness measurements and OD and ID surface defect detection. The destructive examination provided reasonably good confirmation of ''defects'' detected in the nondestructive examination

  3. Standard practice for examination of welds using the alternating current field measurement technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes procedures to be followed during alternating current field measurement examination of welds for baseline and service-induced surface breaking discontinuities. 1.2 This practice is intended for use on welds in any metallic material. 1.3 This practice does not establish weld acceptance criteria. 1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system might not be exact equivalents; therefore, each system shall be used independently of the other. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Experimental investigation of the ion current distribution in microsecond plasma opening switch

    Energy Technology Data Exchange (ETDEWEB)

    Bystritskij, V; Grigor` ev, S; Kharlov, A; Sinebryukhov, A [Russian Academy of Sciences, Tomsk (Russian Federation). Institute of Electrophysics

    1997-12-31

    This paper is devoted to the investigations of properties of the microsecond plasma opening switch (MPOS) as an ion beam source for surface modification. Two plasma sources were investigated: flash-board and cable guns. The detailed measurements of axial and azimuthal distributions of ion current density in the switch were performed. It was found that the azimuthal inhomogeneity of the ion beam increases from the beginning to the end of MPOS. The advantages and problems of this approach are discussed. (author). 5 figs., 2 refs.

  5. Experimental control of power dropouts by current modulation in a semiconductor laser with optical feedback

    International Nuclear Information System (INIS)

    Ticos, Catalin M; Andrei, Ionut R; Pascu, Mihail L; Bulinski, Mircea

    2011-01-01

    The injection current of an external-cavity semiconductor laser working in a regime of low-frequency fluctuations (LFFs) is modulated at several MHz. The rate of power dropouts in the laser emission is correlated with the amplitude and frequency of the modulating signal. The occurrence of dropouts becomes more regular when the laser is driven at 7 MHz, which is close to the dominant frequency of dropouts in the solitary laser. Driving the laser at 10 MHz also induces dropouts with a periodicity of 0.1 μs, resulting in LFFs with two dominant frequencies.

  6. Current technology and techniques in re-mineralization of white spot lesions: A systematic review

    Science.gov (United States)

    Podray, Susan S.

    White Spot lesions are a common iatrogenic occurrence on patients who are treated with fixed orthodontic appliances. There is a dynamic chemical interaction between enamel and saliva at the tooth surface that allow a lesion to have phase changes involving demineralization of enamel and reminerlization. This is due to calcium and phosphate dissolved in saliva that is deposited onto the tooth surface or removed depending on the surrounding pH. Caseinphosphopeptide-amorphous calcium phosphate (CPP-ACP) is gaining popularity in dentistry as a way to increase the available level of calcium and phosphate in plaque and saliva to improve the chemical gradient so that if favors reminerlization. The aim of our investigation is to search the available current literature and formulate a recommendation for use of CPP-ACP in orthodontics. Publications from the following electronic databases were searched: PubMed, Web of Science, Cochrane Library and Science Direct. Searches from August 2010 to April 1st 2012 were performed under the terms "MI Paste OR Recaldent OR caseinphosphopeptide-amorphous calcium phosphate OR CPP-ACP or tooth mousse". The searches yielded 155 articles, These were reviewed for relevance based on inclusion and exclusion criteria. Articles with inappropriate study design or no outcome measures at both baseline and end point were also excluded. 13 articles were deemed of relevance with a high quality study design and were included in this study for evaluation. The current literature suggests a preventative treatment regimen in which MI Paste Plus is used. It should be delivered once daily prior to bed after oral hygiene for 3 minutes in a fluoride tray, throughout orthodontic treatment. It should be recommended for high risk patients determined by poor oral hygiene, as seen by the inability to remove plaque from teeth and appliances. This protocol may prevent or assist in the remineralization of enamel white spot lesions during and after orthodontic treatment.

  7. Experimental design technique applied to the validation of an instrumental Neutron Activation Analysis procedure

    International Nuclear Information System (INIS)

    Santos, Uanda Paula de M. dos; Moreira, Edson Gonçalves

    2017-01-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using short irradiations at a pneumatic system. 2 k experimental designs were applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. The chosen experimental designs were the 2 3 and the 2 4 , depending on the radionuclide half life. Different certified reference materials and multi-element comparators were analyzed considering the following variables: sample decay time, irradiation time, counting time and sample distance to detector. Comparator concentration, sample mass and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations, it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN /CNEN-SP). Optimized conditions were estimated based on the results of z-score tests, main effect, interaction effects and better irradiation conditions. (author)

  8. Return to Our Roots: Raising Radishes to Teach Experimental Design. Methods and Techniques.

    Science.gov (United States)

    Stallings, William M.

    1993-01-01

    Reviews research in teaching applied statistics. Concludes that students should analyze data from studies they have designed and conducted. Describes an activity in which students study germination and growth of radish seeds. Includes a table providing student instructions for both the experimental procedure and data analysis. (CFR)

  9. Effectiveness of a commonly-used technique for experimentally reducing plumage UV reflectance

    NARCIS (Netherlands)

    Korsten, P.; Limbourg, T.; Lessells, C.M.; Komdeur, J.

    2007-01-01

    Ultraviolet (UV) plumage is thought to be sexually selected through intra-sexual competition, female choice and differential allocation. Experimental manipulations of plumage UV reflectance are essential to demonstrate that mate choice or intra-sexual competition are causally related to UV

  10. Effectiveness of a commonly-used technique for experimentally reducing plumage UV reflectance

    NARCIS (Netherlands)

    Korsten, Peter; Limbourg, Tobias; Lessells, Catherine M.; Komdeur, Jan

    Ultraviolet (UV) plumage is thought to be sexually selected through intra-sexual competition, female choice and differential allocation. Experimental manipulations of plumage UV reflectance are essential to demonstrate that mate choice or intra-sexual competition are causally related to UV

  11. Experimental design technique applied to the validation of an instrumental Neutron Activation Analysis procedure

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Uanda Paula de M. dos; Moreira, Edson Gonçalves, E-mail: uandapaula@gmail.com, E-mail: emoreira@ipen.br [Instituto de Pesquisas Energéticas e Nucleares (IPEN/CNEN-SP), São Paulo, SP (Brazil)

    2017-07-01

    In this study optimization of procedures and standardization of Instrumental Neutron Activation Analysis (INAA) method were carried out for the determination of the elements bromine, chlorine, magnesium, manganese, potassium, sodium and vanadium in biological matrix materials using short irradiations at a pneumatic system. 2{sup k} experimental designs were applied for evaluation of the individual contribution of selected variables of the analytical procedure in the final mass fraction result. The chosen experimental designs were the 2{sup 3} and the 2{sup 4}, depending on the radionuclide half life. Different certified reference materials and multi-element comparators were analyzed considering the following variables: sample decay time, irradiation time, counting time and sample distance to detector. Comparator concentration, sample mass and irradiation time were maintained constant in this procedure. By means of the statistical analysis and theoretical and experimental considerations, it was determined the optimized experimental conditions for the analytical methods that will be adopted for the validation procedure of INAA methods in the Neutron Activation Analysis Laboratory (LAN) of the Research Reactor Center (CRPq) at the Nuclear and Energy Research Institute (IPEN /CNEN-SP). Optimized conditions were estimated based on the results of z-score tests, main effect, interaction effects and better irradiation conditions. (author)

  12. An elegant technique for ex vivo imaging in experimental research—Optical coherence tomography (OCT)

    DEFF Research Database (Denmark)

    Tschernig, T.; Thrane, Lars; Jørgensen, Thomas Martini

    2013-01-01

    Optical coherence tomography (OCT) is an elegant technology for imaging of tissues and organs and has been established for clinical use for around a decade. Thus, it is used in vivo but can also serve as a valuable ex vivo imaging tool in experimental research. Here, a brief overview is given...

  13. Experimental investigation of the predictive capabilities of data driven modeling techniques in hydrology - Part 2: Application

    Directory of Open Access Journals (Sweden)

    A. Elshorbagy

    2010-10-01

    Full Text Available In this second part of the two-part paper, the data driven modeling (DDM experiment, presented and explained in the first part, is implemented. Inputs for the five case studies (half-hourly actual evapotranspiration, daily peat soil moisture, daily till soil moisture, and two daily rainfall-runoff datasets are identified, either based on previous studies or using the mutual information content. Twelve groups (realizations were randomly generated from each dataset by randomly sampling without replacement from the original dataset. Neural networks (ANNs, genetic programming (GP, evolutionary polynomial regression (EPR, Support vector machines (SVM, M5 model trees (M5, K-nearest neighbors (K-nn, and multiple linear regression (MLR techniques are implemented and applied to each of the 12 realizations of each case study. The predictive accuracy and uncertainties of the various techniques are assessed using multiple average overall error measures, scatter plots, frequency distribution of model residuals, and the deterioration rate of prediction performance during the testing phase. Gamma test is used as a guide to assist in selecting the appropriate modeling technique. Unlike two nonlinear soil moisture case studies, the results of the experiment conducted in this research study show that ANNs were a sub-optimal choice for the actual evapotranspiration and the two rainfall-runoff case studies. GP is the most successful technique due to its ability to adapt the model complexity to the modeled data. EPR performance could be close to GP with datasets that are more linear than nonlinear. SVM is sensitive to the kernel choice and if appropriately selected, the performance of SVM can improve. M5 performs very well with linear and semi linear data, which cover wide range of hydrological situations. In highly nonlinear case studies, ANNs, K-nn, and GP could be more successful than other modeling techniques. K-nn is also successful in linear situations, and it

  14. Experimental investigation of the predictive capabilities of data driven modeling techniques in hydrology - Part 2: Application

    Science.gov (United States)

    Elshorbagy, A.; Corzo, G.; Srinivasulu, S.; Solomatine, D. P.

    2010-10-01

    In this second part of the two-part paper, the data driven modeling (DDM) experiment, presented and explained in the first part, is implemented. Inputs for the five case studies (half-hourly actual evapotranspiration, daily peat soil moisture, daily till soil moisture, and two daily rainfall-runoff datasets) are identified, either based on previous studies or using the mutual information content. Twelve groups (realizations) were randomly generated from each dataset by randomly sampling without replacement from the original dataset. Neural networks (ANNs), genetic programming (GP), evolutionary polynomial regression (EPR), Support vector machines (SVM), M5 model trees (M5), K-nearest neighbors (K-nn), and multiple linear regression (MLR) techniques are implemented and applied to each of the 12 realizations of each case study. The predictive accuracy and uncertainties of the various techniques are assessed using multiple average overall error measures, scatter plots, frequency distribution of model residuals, and the deterioration rate of prediction performance during the testing phase. Gamma test is used as a guide to assist in selecting the appropriate modeling technique. Unlike two nonlinear soil moisture case studies, the results of the experiment conducted in this research study show that ANNs were a sub-optimal choice for the actual evapotranspiration and the two rainfall-runoff case studies. GP is the most successful technique due to its ability to adapt the model complexity to the modeled data. EPR performance could be close to GP with datasets that are more linear than nonlinear. SVM is sensitive to the kernel choice and if appropriately selected, the performance of SVM can improve. M5 performs very well with linear and semi linear data, which cover wide range of hydrological situations. In highly nonlinear case studies, ANNs, K-nn, and GP could be more successful than other modeling techniques. K-nn is also successful in linear situations, and it should

  15. EXPERIMENTAL

    African Journals Online (AJOL)

    denise

    weight. Animals in the control group were injected with only solvent. An electroconvulsive shock therapy equipment. (Ugo basile ECT UNIT 7801) was used to deliver a current of 50mA for 0.2second duration through the ear lobes. Preliminary test showed that the introduced current produced tonic forelimb and hind limb.

  16. Establishing the Appropriate Attributes in Current Human Reliability Assessment Techniques for Nuclear Safety

    International Nuclear Information System (INIS)

    Bowie, Jane; Munley, Gary; Dang, Vinh; Wreathall, John; Bye, Andreas; Cooper, Susan; Marble, Julie; Peters, Sean; Xing, Jing; Fauchille, Veronique; Fiset, Jean Yves; Haage, Monica; Johanson, Gunnar; Jung, Won Dae; Kim, Jaewhan; Lee, Seung Jung; Kubicek, Jan; Le Bot, Pierre; Pesme, Helene; Preischl, Wolfgang; Salway, Alice; Amri, Abdallah; Lamarre, Greg; White, Andrew; )

    2015-03-01

    This report presents the results of a joint task of the Working Groups on Risk Assessment (WGRISK) and on Human and Organisational Factors (WGHOF) of the OECD/NEA CSNI, to identify desirable attributes of Human Reliability Assessment (HRA) methods, and to evaluate a range of HRA methods used in OECD member countries against those attributes. The purpose of this project is to provide information that will support regulators and operators of nuclear facilities when making judgements about the appropriateness of HRA methods for conducting assessments in support of Probabilistic Safety Assessments (PSA). The task was performed by an international team of Human Factors, HRA and PSA experts from a broad range of OECD member countries. As in other reviews of HRA methods, the study did not set out to recommend or promote the use of any particular HRA method. Rather the study aims to identify the strengths and limitations of commonly used and developing methods to aid those responsible for production of HRAs in selecting appropriate tools for specific HRA applications. The study also aims to assist regulators when making judgements on the appropriateness of the application of an HRA technique within nuclear-related probabilistic safety assessments. The report is aimed at practitioners in the field of human reliability assessment, human factors, and risk assessment more generally

  17. Modern Diagnostic Techniques for the Assessment of Ocular Blood Flow in Myopia: Current State of Knowledge.

    Science.gov (United States)

    Grudzińska, Ewa; Modrzejewska, Monika

    2018-01-01

    Myopia is the most common refractive error and the subject of interest of various studies assessing ocular blood flow. Increasing refractive error and axial elongation of the eye result in the stretching and thinning of the scleral, choroid, and retinal tissues and the decrease in retinal vessel diameter, disturbing ocular blood flow. Local and systemic factors known to change ocular blood flow include glaucoma, medications and fluctuations in intraocular pressure, and metabolic parameters. Techniques and tools assessing ocular blood flow include, among others, laser Doppler flowmetry (LDF), retinal function imager (RFI), laser speckle contrast imaging (LSCI), magnetic resonance imaging (MRI), optical coherence tomography angiography (OCTA), pulsatile ocular blood flowmeter (POBF), fundus pulsation amplitude (FPA), colour Doppler imaging (CDI), and Doppler optical coherence tomography (DOCT). Many researchers consistently reported lower blood flow parameters in myopic eyes regardless of the used diagnostic method. It is unclear whether this is a primary change that causes secondary thinning of ocular tissues or quite the opposite; that is, the mechanical stretching of the eye wall reduces its thickness and causes a secondary lower demand of tissues for oxygen. This paper presents a review of studies assessing ocular blood flow in myopes.

  18. Experimental and mathematical simulation techniques for determining an in-situ response testing method for neutron sensors used in reactor power plant protection systems

    International Nuclear Information System (INIS)

    Behbahani, A.

    1983-01-01

    An analytical neutron sensor response model and methods for transient response measurements of neutron sensors (compensated ionization chamber), including possible in-situ techniques have been developed and evaluated to meet the provisions of Draft Standard ISA Sd67.06, IEEE 338-1977, and NRC Guide 1.118. One in-situ method requires the perturbation of the high voltage detector (sensor) power supply and measurement of the sensor response. The response to a perturbation of the power supply is related to the response of the sensor to a transient change in neutron flux. Random signal analysis is another in-situ technique to monitor the neutron sensor response. In this method the power spectrum of the inherent fluctuations from the neutron sensor output (current in CIC) are measured and evaluated. Transient response techniques (including in-situ methods) are experimentally and analytically evaluated to identify the mechanisms which may cause degradation in the response of the neutron sensors. The objective of the experimental evaluation was to correlate the measured response time using transient radiation flux changes and power supply perturbation. The objective of the analytical model of the different sensor response was to predict response time and degradation mechanisms

  19. An Experimental Study on the Darrieus-Savonius Turbine for the Tidal Current Power Generation

    Science.gov (United States)

    Kyozuka, Yusaku

    The Darrieus turbine is popular for tidal current power generation in Japan. It is simple in structure with straight wings rotating around a vertical axis, so that it has no directionality against the motion of tidal flow which changes its direction twice a day. However, there is one defect in the Darrieus turbine; its small starting torque. Once it stops, a Darrieus turbine is hard to re-start until a fairly fast current is exerted on it. To improve the starting torque of the Darrieus turbine used for tidal power generation, a hybrid turbine, composed of a Darrieus turbine and a Savonius rotor is proposed. Hydrodynamic characteristics of a semi-circular section used for the Savonius bucket were measured in a wind tunnel. The torque of a two bucket Savonius rotor was measured in a circulating water channel, where four different configurations of the bucket were compared. A combined Darrieus and Savonius turbine was tested in the circulating water channel, where the effect of the attaching angle between Darrieus wing and Savonius rotor was studied. Finally, power generation experiments using a 48 pole electric generator were conducted in a towing tank and the power coefficients were compared with the results of experiments obtained in the circulating water channel.

  20. Secondary current properties generated by wind-induced water waves in experimental conditions

    Directory of Open Access Journals (Sweden)

    Michio Sanjou

    2014-06-01

    Full Text Available Secondary currents such as the Langmuir circulation are of high interest in natural rivers and the ocean because they have striking impacts on scour, sedimentation, and mass transport. Basic characteristics have been well-studied in straight open-channel flows. However, little is known regarding secondary circulation induced by wind waves. The presented study describes the generation properties of wind waves observed in the laboratory tank. Wind-induced water waves are known to produce large scale circulations. The phenomenon is observed together with high-speed and low-speed streaks, convergence and divergence zones, respectively. Therefore, it is important to determine the hydrodynamic properties of secondary currents for wind-induced water waves within rivers and lakes. In this study, using two high-speed CMOS cameras, stereoscopic particle image velocimetry (PIV measurements were conducted in order to reveal the distribution of all three components of velocity vectors. The experiments allowed us to investigate the three-dimensional turbulent structure under water waves and the generation mechanism of large-scale circulations. Additionally, a third CMOS camera was used to measure the spanwise profile of thefree-surface elevation. The time-series of velocity components and the free-surface were obtained simultaneously. From our experiments, free-surface variations were found to influence the instantaneous velocity distributions of the cross-sectional plane. We also considered thegeneration process by the phase analysis related to gravity waves and compared the contribution of the apparent stress.

  1. New hadronic currents in TAUOLA: for confrontation with the experimental data

    CERN Document Server

    Was, Z

    2012-01-01

    The status of implementation of new hadronic currents into the Monte Carlo system for simulation of tau-lepton production and decay in high-energy accelerator experiments is reviewed. Since the tau-lepton conference in 2010 substantial progress was achieved: (i) For the TAUOLA Monte Carlo generator of tau-lepton decays, automated and simultaneous use of many versions of form factors for the calculation of optional weights for fits was developed and checked to work in the Belle and BaBar software environment. Alternative parameterizations of hadronic currents based on the Resonance Chiral approach are available now. This was achieved for more than 88% of the total tau hadronic width. (ii) the TAUOLA universal interface based on HepMC (the C++ event record) is available. This is the case for C++ users of PHOTOS Monte Carlo for radiative corrections in decays, as well. An algorithm for weighted events to explore spin effects in analysis of hard processes was prepared. (iii) Kernels featuring a complete first-ord...

  2. CALCULATION-EXPERIMENTAL METHOD OF RESEARCH IN A METALLIC CONDUCTOR WITH THE PULSE CURRENT OF ELECTRONIC WAVEPACKAGES AND DE BROGLIE ELECTRONIC HALF-WAVES

    Directory of Open Access Journals (Sweden)

    M. I. Baranov

    2016-12-01

    Full Text Available Purpose. Development of calculation-experimental method for a discovery and study of electronic wavepackages (EWP and of de Broglie electronic half-waves in a metallic conductor with the pulse axial-flow current of high density. Methodology. Theoretical bases of the electrical engineering, bases of quantum physics, electrophysics bases of technique of high voltage and large pulsecurrents, and also bases of technique of measuring of permanent and variable electric value. Results. On the basis of generalization of results of research of features of the longitudinal wave periodic distributing of negatively charged transmitters of electric current of conductivity in the thin round continuous zincked steel wire offered and approved in the conditions of high-voltage laboratory method for a discovery and direct determination in him of geometrical parameters of «hot» and «cold» longitudinal areas quantized periodic longitudinal EWP and accordingly the mediated determination of values of the quantized lengths formative their de Broglie electronic half-waves. It is shown that results of close quantum mechanical calculations of EWP and quantized lengths λenz/2 of longitudinal de Broglie half-waves for the probed wire long l0 well comport with the results of the executed high temperature experiments on the powerful high-voltage generator of homopolar large pulse current of millisecond duration. Originality. First calculation-experimental a way the important for the theory of electricity fact of existence is set in a round metallic explorer with the impulsive axial-flow current of the quantized coherent de Broglie electronic half-waves, amplitudes of which at the quantum number of n=1,3,9 correspond the middles of «hot» longitudinal areas of EWP. Calculation quantum mechanical correlation of type of λenz/2=l0/n got experimental confirmation, in obedience to which on length of l0 conductor the integer of quantized electronic half-waves is always laid

  3. The techniques of quality operations computational and experimental researches of the launch vehicles in the drawing-board stage

    Science.gov (United States)

    Rozhaeva, K.

    2018-01-01

    The aim of the researchis the quality operations of the design process at the stage of research works on the development of active on-Board system of the launch vehicles spent stages descent with liquid propellant rocket engines by simulating the gasification process of undeveloped residues of fuel in the tanks. The design techniques of the gasification process of liquid rocket propellant components residues in the tank to the expense of finding and fixing errors in the algorithm calculation to increase the accuracy of calculation results is proposed. Experimental modelling of the model liquid evaporation in a limited reservoir of the experimental stand, allowing due to the false measurements rejection based on given criteria and detected faults to enhance the results reliability of the experimental studies; to reduce the experiments cost.

  4. A comparative study on the property determination of metal matrix composites using ultrasonic and eddy current techniques

    International Nuclear Information System (INIS)

    Jeong, Hyun Jo

    1997-01-01

    Ultrasonic and eddy current methods were developed for the quantitative determination of material properties in particulate reinforced metal matrix composites. The proposed techniques employed measurements of ultrasonic velocity and eddy current conductivity, together with theoretical models which relate the effective anisotropic properties of the composites to their microstructures. The approach was used for a wide range of SiC particulate reinforced Al matrix(SiC p /Al) composites to estimate the particulate volume fractions of the composites. The SiC p volume fraction was calculated by coupling the measured velocity and conductivity with their corresponding model predictions. Both methods were shown to be reliable in determining the reinforcement volume fractions. However, the ultrasonic method was found to be better than the eddy current method, since the electrical conductivity was sensitive to the presence of intermetallic compounds formed during processing stage.

  5. Experimental investigation of localized stress-induced leakage current distribution in gate dielectrics using array test circuit

    Science.gov (United States)

    Park, Hyeonwoo; Teramoto, Akinobu; Kuroda, Rihito; Suwa, Tomoyuki; Sugawa, Shigetoshi

    2018-04-01

    Localized stress-induced leakage current (SILC) has become a major problem in the reliability of flash memories. To reduce it, clarifying the SILC mechanism is important, and statistical measurement and analysis have to be carried out. In this study, we applied an array test circuit that can measure the SILC distribution of more than 80,000 nMOSFETs with various gate areas at a high speed (within 80 s) and a high accuracy (on the 10-17 A current order). The results clarified that the distributions of localized SILC in different gate areas follow a universal distribution assuming the same SILC defect density distribution per unit area, and the current of localized SILC defects does not scale down with the gate area. Moreover, the distribution of SILC defect density and its dependence on the oxide field for measurement (E OX-Measure) were experimentally determined for fabricated devices.

  6. Techniques used for the screening of hemoglobin levels in blood donors: current insights and future directions

    Directory of Open Access Journals (Sweden)

    Chaudhary R

    2017-07-01

    Full Text Available Rajendra Chaudhary,1 Anju Dubey,2 Atul Sonker3 1Department of Transfusion Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, 2Department of Transfusion Medicine, T.S. Misra Medical College and Hospital, 3Department of Transfusion Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India Abstract: Blood donor hemoglobin (Hb estimation is an important donation test that is performed prior to blood donation. It serves the dual purpose of protecting the donors’ health against anemia and ensuring good quality of blood components, which has an implication on recipients’ health. Diverse cutoff criteria have been defined world over depending on population characteristics; however, no testing methodology and sample requirement have been specified for Hb screening. Besides the technique, there are several physiological and methodological factors that affect accuracy and reliability of Hb estimation. These include the anatomical source of blood sample, posture of the donor, timing of sample and several other biological factors. Qualitative copper sulfate gravimetric method has been the archaic time-tested method that is still used in resource-constrained settings. Portable hemoglobinometers are modern quantitative devices that have been further modified to reagent-free cuvettes. Furthermore, noninvasive spectrophotometry was introduced, mitigating pain to blood donor and eliminating risk of infection. Notwithstanding a tremendous evolution in terms of ease of operation, accuracy, mobility, rapidity and cost, a component of inherent variability persists, which may partly be attributed to pre-analytical variables. Hence, blood centers should pay due attention to validation of test methodology, competency of operating staff and regular proficiency testing of the outputs. In this article, we have reviewed various regulatory guidelines, described the variables that affect the measurements and compared the validated

  7. Monitoring techniques for the impact assessment during nuclear and radiological emergencies: current status and the challenges

    International Nuclear Information System (INIS)

    Pradeepkumar, K.S.; Sharma, D.N.

    2003-01-01

    Preparedness and response capability for Nuclear and Radiological emergencies, existing world over, are mainly based on the requirement of responding to radiation emergency caused by nuclear or radiological accidents. Cosmos satellite accident, plutonium contamination at Polaris, nuclear accidents like Kystium, Windscale, TMI and Chernobyl, radiological accidents at Goiania etc have demonstrated the requirement of improved radiation monitoring techniques. For quick decision making, state of the art monitoring methodology which can support quantitative and qualitative impact assessment is essential. Evaluation of radiological mapping of the area suspected to be contaminated needs ground based as well as aerial based monitoring systems to predict the level of radioactive contamination on ground. This will help in delineating the area and deciding the required countermeasures, based on the quantity and type of radionuclides responsible for it. The response can be successful with the effective use of i) Early Warning System ii) Mobile Monitoring System and iii) Aerial Gamma Spectrometric System. Selection of the monitoring methodology and survey parameters and assessment of situation using available resources etc. are to be optimized depending on the accident scenario. Recently, many countries and agencies like IAEA have expressed the requirement for responding to other types of nuclear/radiological emergencies i.e, man made radiation emergency situations aimed at harming public at large that can also lead to environmental contamination and significant exposure to public. Reports of lost / misplaced / stolen radioactive sources from many countries are alarming as safety and security of these radioactive sources are under challenge. The monitoring methodology has to take into account of the increase in such demands and more periodic monitoring in suspected locations is to be carried out. Detection of orphan sources possible amidst large heap of metallic scraps may pose

  8. Enhancing Self-Efficacy and Performance: An Experimental Comparison of Psychological Techniques

    Science.gov (United States)

    Wright, Bradley James; O'Halloran, Paul Daniel; Stukas, Arthur Anthony

    2016-01-01

    Purpose: We assessed how 6 psychological performance enhancement techniques (PETs) differentially improved self-efficacy (SE) and skill performance. We also assessed whether vicarious experiences and verbal persuasion as posited sources of SE (Bandura, 1982) were supported and, further, if the effects of the 6 PETs remained after controlling for…

  9. An Experimental Study of the Effectiveness of Attitude Change Techniques for Enhancing Self-Esteem

    Science.gov (United States)

    Friedenberg, William P.; Gillis, John S.

    1977-01-01

    Attempts to determine whether a maladaptive attitude, frequently observed in therapy clients, could be altered by the use of a counter-attitudinal message. The attitude at which this counter-attitudinal technique is directed is that of low self-esteem. (Author/RK)

  10. Simulation and experimental tests of a real-time DPWM technique ...

    African Journals Online (AJOL)

    This control strategy is a simple and an easy technique generating the same switching pattern as space vector modulation with less switching losses and reduced total harmonic distortion. The main motivation of the present paper is that the DPWM is not largely and deeply investigated and can present a serious alternative ...

  11. An Experimental Technique for Structural Diagnostic Based on Laser Vibrometry and Neural Networks

    Directory of Open Access Journals (Sweden)

    Paolo Castellini

    2000-01-01

    Full Text Available In recent years damage detection techniques based on vibration data have been largely investigated with promising results for many applications. In particular, several attempts have been made to determine which kind of data should be extracted for damage monitoring.

  12. An experimental investigation of cathode erosion in high current magnetoplasmadynamic arc discharges

    Science.gov (United States)

    Codron, Douglas A.

    Since the early to mid 1960's, laboratory studies have demonstrated the unique ability of magnetoplasmadynamic (MPD) thrusters to deliver an exceptionally high level of specific impulse and thrust at large power processing densities. These intrinsic advantages are why MPD thrusters have been identified as a prime candidate for future long duration space missions, including piloted Mars, Mars cargo, lunar cargo, and other missions beyond low Earth orbit (LEO). The large total impulse requirements inherent of the long duration space missions demand the thruster to operate for a significant fraction of the mission burn time while requiring the cathodes to operate at 50 to 10,000 kW for 2,000 to 10,000 hours. The high current levels lead to high operational temperatures and a corresponding steady depletion of the cathode material by evaporation. This mechanism has been identified as the life-limiting component of MPD thrusters. In this research, utilizing subscale geometries, time dependent cathode axial temperature profiles under varying current levels (20 to 60 A) and argon gas mass flow rates (450 to 640 sccm) for both pure and thoriated solid tungsten cathodes were measured by means of both optical pyrometry and charged-coupled (CCD) camera imaging. Thoriated tungsten cathode axial temperature profiles were compared against those of pure tungsten to demonstrate the large temperature reducing effect lowered work function imparts by encouraging increased thermionic electron emission from the cathode surface. Also, Langmuir probing was employed to measure the electron temperature, electron density, and plasma potential near the "active zone" (the surface area of the cathode responsible for approximately 70% of the emitted current) in order to characterize the plasma environment and verify future model predictions. The time changing surface microstructure and elemental composition of the thoriated tungsten cathodes were analyzed using a scanning electron microscope

  13. Current status of experimental breeder reactor-II [EBR-II] shutdown planning

    International Nuclear Information System (INIS)

    McDermott, M. D.; Griffin, C. D.; Michelbacher, J. A.; Earle, O. K.

    2000-01-01

    The Experimental Breeder Reactor--II (EBR-II) at Argonne National Laboratory--West (ANL-W) in Idaho, was shutdown in September, 1994 as mandated by the US Department of Energy. This sodium cooled reactor had been in service since 1964, and was to be placed in an industrially and radiologically safe condition for ultimate decommissioning. The deactivation of a liquid metal reactor presents unique concerns. The first major task associated with the project was the removal of all fueled assemblies. In addition, sodium must be drained from systems and processed for ultimate disposal. Residual quantities of sodium remaining in systems must be deactivated or inerted to preclude future hazards associated with pyrophoricity and generation of potentially explosive hydrogen gas. A Sodium Process Facility was designed and constructed to react the elemental sodium from the EBR-II primary and secondary systems to sodium hydroxide for disposal. This facility has a design capacity to allow the reaction of the complete inventory of sodium at ANL-W in less than two years. Additional quantities of sodium from the Fermi-1 reactor are also being treated at the Sodium Process Facility. The sodium environment and the EBR-II configuration, combined with the radiation and contamination associated with thirty years of reactor operation, posed problems specific to liquid metal reactor deactivation. The methods being developed and implemented at EBR-II can be applied to other similar situations in the US and abroad

  14. Exploring the costs and benefits of social information use: an appraisal of current experimental evidence.

    Science.gov (United States)

    Rieucau, Guillaume; Giraldeau, Luc-Alain

    2011-04-12

    Research on social learning has focused traditionally on whether animals possess the cognitive ability to learn novel motor patterns from tutors. More recently, social learning has included the use of others as sources of inadvertent social information. This type of social learning seems more taxonomically widespread and its use can more readily be approached as an economic decision. Social sampling information, however, can be tricky to use and calls for a more lucid appraisal of its costs. In this four-part review, we address these costs. Firstly, we address the possibility that only a fraction of group members are actually providing social information at any one time. Secondly, we review experimental research which shows that animals are circumspect about social information use. Thirdly, we consider the cases where social information can lead to incorrect decisions and finally, we review studies investigating the effect of social information quality. We address the possibility that using social information or not is not a binary decision and present results of a study showing that nutmeg mannikins combine both sources of information, a condition that can lead to the establishment of informational cascades. We discuss the importance of empirically investigating the economics of social information use.

  15. Assessment of current techniques for reduction of indoor radon concentration in existing and new houses in European countries

    International Nuclear Information System (INIS)

    Holmgren, O.; Arvela, H.

    2012-03-01

    Radon control technologies aim at the reduction of indoor radon concentrations in existing buildings and in new construction through remedial and preventive measures. In recent years, rising ecological awareness and rising energy costs have stimulated the development of low energy and passive houses to save energy. This report contains the analysis and assessment of current techniques and technologies used to achieve the reduction of indoor radon concentrations in existing and new houses with regard to the reduction efficiency and potential impact on energy consumption (qualitative analysis). A questionnaire was prepared and sent to all RADPAR partners in 14 different countries in order to gather national information about the current remediation and prevention techniques. Responses with variable amounts of information were obtained. Based on the questionnaire responses, the status of radon remediation and prevention in each country was assessed, in addition to the reduction efficiency and potential impact on energy consumption of the current remediation and prevention techniques. The number of dwellings with an elevated indoor radon concentration typically ranges from tens of thousands to a million. The percentage of these houses already remediated varies from zero to 15%. Preventive measures in new construction have been taken from a small number of houses to over half a million houses. The research data on the current situation, the number of houses with preventive measures and the efficiency of these measures is currently still quite inadequate. Assessment of the techniques and also the surveys aiming at exploring the impact of remedial and preventive measures is greatly needed in order to promote the work at the national level. The most efficient remediation method is the active sub-slab depressurization (SSD) and the radon well, for which the reduction in the radon concentration is typically 70 - 95%. Other methods, such as sealing entry routes and improving

  16. Applicability of eddy current inversion techniques to the sizing of defects in Inconel welds of BWR internals

    International Nuclear Information System (INIS)

    Yusa, Noritaka; Janousek, Ladislav; Rebican, Mihai; Chen, Zhenmao; Miya, Kenzo; Machida, Eiji

    2004-01-01

    This paper evaluates the applicability of eddy current inversion techniques to the sizing of defects in Inconel welds with rough surfaces. For this purpose, a plate Inconel weld specimen, which models the welding of a stub tube in a boiling water nuclear reactor, is fabricated, and artificial notches machined into the specimen. Eddy current inspections using six probes in weld inspection evaluated. It is revealed that if suitable probes are applied, an Inconel weld does not provide large noise signals in eddy current inspections even though the surface of the weld is rough. Finally, reconstruction of the notches are performed using eddy current signals measured with the use of the uniform eddy current probe that showed the best results among the six probes in the inspection. A simplified configuration is proposed in order to consider the complicated configuration of the welded specimen in numerical simulations. While reconstructed profiles of the notches are slightly larger than the true profiles, quite good agreements are obtained in spite of the simple approximation of the configuration, which reveals that eddy current testing would be an efficient non-destructive testing method for the sizing of defects in Inconel welds. (author)

  17. Modeling drain current of indium zinc oxide thin film transistors prepared by solution deposition technique

    Science.gov (United States)

    Qiang, Lei; Liang, Xiaoci; Cai, Guangshuo; Pei, Yanli; Yao, Ruohe; Wang, Gang

    2018-06-01

    Indium zinc oxide (IZO) thin film transistor (TFT) deposited by solution method is of considerable technological interest as it is a key component for the fabrication of flexible and cheap transparent electronic devices. To obtain a principal understanding of physical properties of solution-processed IZO TFT, a new drain current model that account for the charge transport is proposed. The formulation is developed by incorporating the effect of gate voltage on mobility and threshold voltage with the carrier charges. It is demonstrated that in IZO TFTs the below threshold regime should be divided into two sections: EC - EF > 3kT and EC - EF ≤ 3kT, where kT is the thermal energy, EF and EC represent the Fermi level and the conduction band edge, respectively. Additionally, in order to describe conduction mechanisms more accurately, the extended mobility edge model is conjoined, which can also get rid of the complicated and lengthy computations. The good agreement between measured and calculated results confirms the efficiency of this model for the design of integrated large-area thin film circuits.

  18. An efficient diagnostic technique for distribution systems based on under fault voltages and currents

    Energy Technology Data Exchange (ETDEWEB)

    Campoccia, A.; Di Silvestre, M.L.; Incontrera, I.; Riva Sanseverino, E. [Dipartimento di Ingegneria Elettrica elettronica e delle Telecomunicazioni, Universita degli Studi di Palermo, viale delle Scienze, 90128 Palermo (Italy); Spoto, G. [Centro per la Ricerca Elettronica in Sicilia, Monreale, Via Regione Siciliana 49, 90046 Palermo (Italy)

    2010-10-15

    Service continuity is one of the major aspects in the definition of the quality of the electrical energy, for this reason the research in the field of faults diagnostic for distribution systems is spreading ever more. Moreover the increasing interest around modern distribution systems automation for management purposes gives faults diagnostics more tools to detect outages precisely and in short times. In this paper, the applicability of an efficient fault location and characterization methodology within a centralized monitoring system is discussed. The methodology, appropriate for any kind of fault, is based on the use of the analytical model of the network lines and uses the fundamental components rms values taken from the transient measures of line currents and voltages at the MV/LV substations. The fault location and identification algorithm, proposed by the authors and suitably restated, has been implemented on a microprocessor-based device that can be installed at each MV/LV substation. The speed and precision of the algorithm have been tested against the errors deriving from the fundamental extraction within the prescribed fault clearing times and against the inherent precision of the electronic device used for computation. The tests have been carried out using Matlab Simulink for simulating the faulted system. (author)

  19. Frequency Optimization for Enhancement of Surface Defect Classification Using the Eddy Current Technique

    Science.gov (United States)

    Fan, Mengbao; Wang, Qi; Cao, Binghua; Ye, Bo; Sunny, Ali Imam; Tian, Guiyun

    2016-01-01

    Eddy current testing is quite a popular non-contact and cost-effective method for nondestructive evaluation of product quality and structural integrity. Excitation frequency is one of the key performance factors for defect characterization. In the literature, there are many interesting papers dealing with wide spectral content and optimal frequency in terms of detection sensitivity. However, research activity on frequency optimization with respect to characterization performances is lacking. In this paper, an investigation into optimum excitation frequency has been conducted to enhance surface defect classification performance. The influences of excitation frequency for a group of defects were revealed in terms of detection sensitivity, contrast between defect features, and classification accuracy using kernel principal component analysis (KPCA) and a support vector machine (SVM). It is observed that probe signals are the most sensitive on the whole for a group of defects when excitation frequency is set near the frequency at which maximum probe signals are retrieved for the largest defect. After the use of KPCA, the margins between the defect features are optimum from the perspective of the SVM, which adopts optimal hyperplanes for structure risk minimization. As a result, the best classification accuracy is obtained. The main contribution is that the influences of excitation frequency on defect characterization are interpreted, and experiment-based procedures are proposed to determine the optimal excitation frequency for a group of defects rather than a single defect with respect to optimal characterization performances. PMID:27164112

  20. Innovations in surgery simulation: a review of past, current and future techniques.

    Science.gov (United States)

    Badash, Ido; Burtt, Karen; Solorzano, Carlos A; Carey, Joseph N

    2016-12-01

    As a result of recent work-hours limitations and concerns for patient safety, innovations in extraclinical surgical simulation have become a desired part of residency education. Current simulation models, including cadaveric, animal, bench-top, virtual reality (VR) and robotic simulators are increasingly used in surgical training programs. Advances in telesurgery, three-dimensional (3D) printing, and the incorporation of patient-specific anatomy are paving the way for simulators to become integral components of medical training in the future. Evidence from the literature highlights the benefits of including simulations in surgical training; skills acquired through simulations translate into improvements in operating room performance. Moreover, simulations are rapidly incorporating new medical technologies and offer increasingly high-fidelity recreations of procedures. As a result, both novice and expert surgeons are able to benefit from their use. As dedicated, structured curricula are developed that incorporate simulations into daily resident training, simulated surgeries will strengthen the surgeon's skill set, decrease hospital costs, and improve patient outcomes.

  1. Experimental pain processing in individuals with cognitive impairment: current state of the science

    DEFF Research Database (Denmark)

    Defrin, R; Amanzio, Martina; de Tomasso, M

    2015-01-01

    Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained and complex healthcare needs which frequently include pain. However, individuals with CI can have difficulty...... of neurological and neurodegenerative disorders in which CI is typically present. Overall, the existing data suggest that pain processing is altered in most individuals with CI compared to cognitively intact matched controls. The precise nature of these alterations varies with the type of CI (or associated...... to cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited, but may be enhanced through the use of animal models of CI which also exhibit alterations in nociceptive responding. Further research employing additional behavioural...

  2. Experimental and theoretical study of helical explosive electrical current generators with magnetic field compression

    International Nuclear Information System (INIS)

    Antoni, Bernard; Nazet, Christian.

    1975-07-01

    A generator of electrical energy in which magnetic field compression is achieved by a solid explosive is described. The magnetic flux losses have been calculated for generators of various configurations by the skin depth concept. Calculations take the Joule heating of conductors into account. In helical generators the magnetic flux losses are higher than those calculated by considering diffusion only. Additional losses approximately as important as diffusion losses have already been observed elsewhere on similar devices. Detailed calculations of the motion of the explosively driven inner conductor show that losses come from the jumps encountered by sliding contact moving along the helix. The jumps are caused by little geometrical defects and the consequence on losses is strongly dependent on current intensity. The jumps decrease when the pitch of helix increases. The jumps are detrimental to the efficient use of the explosive energy. With helical generators only 5% of the energy is transferred into magnetic energy [fr

  3. An experimental investigation of heat transfer enhancement in minichannel: Combination of nanofluid and micro fin structure techniques

    DEFF Research Database (Denmark)

    Zhang, Ji; Diao, Yanhua; Zhao, Yaohua

    2017-01-01

    This work experimentally studied the single-phase heat transfer and pressure drop characteristics by using two heat transfer enhancement techniques (micro fin structure and nanofluids) in multiport minichannel flat tube (MMFT). MMFT consisted of numerous parallel rectangular minichannels...... and is widely used in industry as the heat transfer unit of a heat exchanger. Firstly, the enhanced heat transfer performances by individually using one enhancement technique were investigated by testing Nusselt number, friction factor and performance evaluation criterion (PEC). In this section, five MMFTs...... with different micro fin numbers (N = 0, 1, 2, 3 and 4) and nanofluids with three volume concentrations (φ = 0.005%, 0.01% and 0.1%) were used as test sections and working fluids respectively. Secondly, the experiments using two combined enhancement technique were performed. By using conjunctively two...

  4. New experimental research stand SVICKA neutron field analysis using neutron activation detector technique

    Science.gov (United States)

    Varmuza, Jan; Katovsky, Karel; Zeman, Miroslav; Stastny, Ondrej; Haysak, Ivan; Holomb, Robert

    2018-04-01

    Knowledge of neutron energy spectra is very important because neutrons with various energies have a different material impact or a biological tissue impact. This paper presents basic results of the neutron flux distribution inside the new experimental research stand SVICKA which is located at Brno University of Technology in Brno, Czech Republic. The experiment also focused on the investigation of the sandwich biological shielding quality that protects staff against radiation effects. The set of indium activation detectors was used to the investigation of neutron flux distribution. The results of the measurement provide basic information about the neutron flux distribution inside all irradiation channels and no damage or cracks are present in the experimental research stand biological shielding.

  5. Experimental-calculation technique for Ksub(IC) determination using the samples of decreased dimensions

    International Nuclear Information System (INIS)

    Vinokurov, V.A.; Dymshits, A.V.; Pirusskij, M.V.; Ovsyannikov, B.M.; Kononov, V.V.

    1981-01-01

    A possibility to decrease the size of samples, which is necessary for the reliable determination of fractUre toughness Ksub(1c), is established. The dependences of crack-resistance caracteristics on the sample dimensions are determined experimentally. The static bending tests are made using the 1251 model of ''Instron'' installation with a specially designed device. The samples of the 20KhNMF steel have been tested. It is shown that the Ksub(1c) value, determined for the samples with the largest netto cross section (50x100 rm), is considerably lower than Ksub(1c) values, determined for the samples with the decreased sizes. it is shown that the developed experimental-calculated method of Ksub(1c) determination can be practically used for the samples of the decreased sizes with the introduction of the corresponding amendment coefficient [ru

  6. [Hormonal mechanisms of pathogenesis and cure of experimental gastroduodenal ulcer by the Okabe technique].

    Science.gov (United States)

    Frolkov, V K; Polushina, N D; Shvarts, V Ia; Kozharskiĭ, V V; Zaporozhchenko, I G; Kartazaeva, V A

    1992-01-01

    The dynamics of hormonal secretion was studied in relation with the development of an ulcer defect in rats with acetate-induced gastroduodenal ulcer after Okabe. The formation of the ulcer was accompanied by increased gastrin, glucagon, cortisol, growth hormone, and histamine secretion and reduced glucose tolerance. The level of intragastric pH reduced, the activity of proteolytic enzymes in the gastrointestinal tract increased. Correlation analysis bore evidence for the contribution of gastroenteropancreatic hormones to the compensatory-adaptational responses, whereas with a higher blood cortisol level the surface of the ulcer defect was larger. Oral mineral water (Essentuki No. 17) promoted the secretion of gastrin, glucagon, and insulin and the experimental ulcers grew smaller in this case. The involvement of the hormonal factors in the mechanisms of the development of experimental acetate-induced ulcer is discussed.

  7. Experimental study and technique for calculation of critical heat fluxes in helium boiling in tubes

    International Nuclear Information System (INIS)

    Arkhipov, V.V.; Kvasnyuk, S.V.; Deev, V.I.; Andreev, V.K.

    1979-01-01

    Studied is the effect of regime parameters on critical heat loads in helium boiling in a vertical tube in the range of mass rates of 80 2 xc) and pressures of 100<=p<=200 kPa for the vapor content range corresponding to the heat exchange crisis of the first kind. The method for calculating critical heat fluxes describing experimental data with the error less than +-15% is proposed. The critical heat loads in helium boiling in tubes reduce with the growth of pressure and vapor content in the regime parameter ranges under investigation. Both positive and negative effects of the mass rate on the critical heat flux are observed. The calculation method proposed satisfactorily describes the experimental data

  8. Experimental study of TJ-1 plasma using scattering and radiation emission techniques

    International Nuclear Information System (INIS)

    Pardo, C.; Zurro, B.

    1987-01-01

    The Thomson scattering system of TJ-1 is described in detail. The radial profiles of Te and ne obtained in TJ-1 discharges are presented. This data make possible to deduce characteristic parameters of the plasma confinement in this machine, as energy confinement times, Zeff B. Using also radiation measurements (global and in the visible range) we obtained the particle confinement time and Zeff without non experimental assumptions. (Author) 52 refs

  9. Computer techniques for experimental work in GDR nuclear power plants with WWER

    International Nuclear Information System (INIS)

    Stemmler, G.

    1985-01-01

    Nuclear power plant units with WWER are being increasingly equipped with high-performance, programmable process control computers. There are, however, essential reasons for further advancing the development of computer-aided measuring systems, in particular for experimental work. A special structure of such systems, which is based on the division into relatively rigid data registration and primary handling and into further processing by advanced programming language, has proved useful in the GDR. (author)

  10. Physiotherapists use a small number of behaviour change techniques when promoting physical activity: A systematic review comparing experimental and observational studies.

    Science.gov (United States)

    Kunstler, Breanne E; Cook, Jill L; Freene, Nicole; Finch, Caroline F; Kemp, Joanne L; O'Halloran, Paul D; Gaida, James E

    2018-06-01

    Physiotherapists promote physical activity as part of their practice. This study reviewed the behaviour change techniques physiotherapists use when promoting physical activity in experimental and observational studies. Systematic review of experimental and observational studies. Twelve databases were searched using terms related to physiotherapy and physical activity. We included experimental studies evaluating the efficacy of physiotherapist-led physical activity interventions delivered to adults in clinic-based private practice and outpatient settings to individuals with, or at risk of, non-communicable diseases. Observational studies reporting the techniques physiotherapists use when promoting physical activity were also included. The behaviour change techniques used in all studies were identified using the Behaviour Change Technique Taxonomy. The behaviour change techniques appearing in efficacious and inefficacious experimental interventions were compared using a narrative approach. Twelve studies (nine experimental and three observational) were retained from the initial search yield of 4141. Risk of bias ranged from low to high. Physiotherapists used seven behaviour change techniques in the observational studies, compared to 30 behaviour change techniques in the experimental studies. Social support (unspecified) was the most frequently identified behaviour change technique across both settings. Efficacious experimental interventions used more behaviour change techniques (n=29) and functioned in more ways (n=6) than did inefficacious experimental interventions (behaviour change techniques=10 and functions=1). Physiotherapists use a small number of behaviour change techniques. Less behaviour change techniques were identified in observational studies compared to experimental studies, suggesting physiotherapists use less BCTs clinically than experimentally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  11. The development of human factors technologies -The development of human factors experimental evaluation techniques-

    International Nuclear Information System (INIS)

    Shim, Bong Sik; Oh, In Suk; Cha, Kyung Hoh; Lee, Hyun Chul

    1995-07-01

    In this year, we studied the followings: 1) Development of operator mental workload evaluation techniques, 2) Development of a prototype for preliminary human factors experiment, 3) Suitability test of information display on a large scale display panel, 4) Development of guidelines for VDU-based control room design, 5) Development of integrated test facility (ITF). 6) Establishment of an eye tracking system, and we got the following results: 1) Mental workload evaluation techniques for MMI evaluation, 2) PROTOPEX (PROTOtype for preliminary human factors experiment) for preliminary human factors experiments, 3) Usage methods of APTEA (Analysis-Prototyping-Training-Experiment-Analysis) experiment design, 4) Design guidelines for human factors verification, 5) Detail design requirements and development plan of ITF, 6) Eye movement measurement system. 38 figs, 20 tabs, 54 refs. (Author)

  12. An Experimental Study of Turbulent Skin Friction Reduction in Supersonic Flow Using a Microblowing Technique

    Science.gov (United States)

    Hwang, Danny P.

    1999-01-01

    A new turbulent skin friction reduction technology, called the microblowing technique has been tested in supersonic flow (Mach number of 1.9) on specially designed porous plates with microholes. The skin friction was measured directly by a force balance and the boundary layer development was measured by a total pressure rake at the tailing edge of a test plate. The free stream Reynolds number was 1.0(10 exp 6) per meter. The turbulent skin friction coefficient ratios (C(sub f)/C(sub f0)) of seven porous plates are given in this report. Test results showed that the microblowing technique could reduce the turbulent skin friction in supersonic flow (up to 90 percent below a solid flat plate value, which was even greater than in subsonic flow).

  13. An experimental result of estimating an application volume by machine learning techniques.

    Science.gov (United States)

    Hasegawa, Tatsuhito; Koshino, Makoto; Kimura, Haruhiko

    2015-01-01

    In this study, we improved the usability of smartphones by automating a user's operations. We developed an intelligent system using machine learning techniques that periodically detects a user's context on a smartphone. We selected the Android operating system because it has the largest market share and highest flexibility of its development environment. In this paper, we describe an application that automatically adjusts application volume. Adjusting the volume can be easily forgotten because users need to push the volume buttons to alter the volume depending on the given situation. Therefore, we developed an application that automatically adjusts the volume based on learned user settings. Application volume can be set differently from ringtone volume on Android devices, and these volume settings are associated with each specific application including games. Our application records a user's location, the volume setting, the foreground application name and other such attributes as learning data, thereby estimating whether the volume should be adjusted using machine learning techniques via Weka.

  14. Experimental study of capacity of the blood blow of spinal cord using radiolabelling microspbere technique

    International Nuclear Information System (INIS)

    Hu Xuan; Li Rui

    2007-01-01

    Objective In order to study the relation ship between local blood flow and neurofunction at the later stage of spinal injury. Method: Measured the capacity of the local blood flow in the spinal cord injury by the radiolabelling microsphere technique and scored the nervus function grade. Result: There are no correlation between the local blood flow and the nervus function. Conclusion: It is obvious that the increase of the local blood supply can't reflect the nervus function. (authors)

  15. Novel Method for Sizing Metallic Bottom Crack Depth Using Multi-frequency Alternating Current Potential Drop Technique

    Directory of Open Access Journals (Sweden)

    Li Yuting

    2015-10-01

    Full Text Available 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.

  16. Transanal endoscopic microsurgery as technique surgical for the treatment of the rectal adenocarcinoma: history, evolution and current tendency

    International Nuclear Information System (INIS)

    Vega Padilla, Luis Carlos

    2013-01-01

    The modalities of local and minimally invasive treatment were described for early rectal adenocarcinomas. The most adequate diagnostic studies and interdisciplinary interactions involved were considered in the process and the therapeutic results, in comparison with the current radical treatments. The historical evolution of the different surgical techniques developed over time, and the anatomical and physiological concepts were reviewed. The epidemiological behavior of the disease was documented according to gender, age and most prevalent sites to direct the possible risk groups to suffer the disease. Risk factors that affect patients with colorectal cancer were identified and related to the environment, social habits and hereditary. The different genetic syndromes involved in colorectal cancer, its physiopathology and clinical manifestations and implications were examined with respect to colorectal cancer. Colorectal cancer was defined according to the updated classifications of the American Joint Cancer Committee, according to the depth, affectation of lymph nodes and metastasis to distant organs, in relation to its clinical stage. Current surgical techniques were named to treat early adenocarcinomas of inferior rectus. The different risk factors were analyzed to allow local resections of the early rectal tumors, from the histopalogical, radiological and clinical point of view. The traditional techniques of transanal and radical resection were compared against the transanal endoscopic microsurgery between different aspects such as technical difficulty, recurrence rate, morbidity and mortality, and economic cost [es

  17. Comparison of advanced optical imaging techniques with current otolaryngology diagnostics for improved middle ear assessment (Conference Presentation)

    Science.gov (United States)

    Nolan, Ryan M.; Shelton, Ryan L.; Monroy, Guillermo L.; Spillman, Darold R.; Novak, Michael A.; Boppart, Stephen A.

    2016-02-01

    Otolaryngologists utilize a variety of diagnostic techniques to assess middle ear health. Tympanometry, audiometry, and otoacoustic emissions examine the mobility of the tympanic membrane (eardrum) and ossicles using ear canal pressure and auditory tone delivery and detection. Laser Doppler vibrometry provides non-contact vibrational measurement, and acoustic reflectometry is used to assess middle ear effusion using sonar. These technologies and techniques have advanced the field beyond the use of the standard otoscope, a simple tissue magnifier, yet the need for direct visualization of middle ear disease for superior detection, assessment, and management remains. In this study, we evaluated the use of portable optical coherence tomography (OCT) and pneumatic low-coherence interferometry (LCI) systems with handheld probe delivery to standard tympanometry, audiometry, otoacoustic emissions, laser Doppler vibrometry, and acoustic reflectometry. Comparison of these advanced optical imaging techniques and current diagnostics was conducted with a case study subject with a history of unilateral eardrum trauma. OCT and pneumatic LCI provide novel dynamic spatiotemporal structural data of the middle ear, such as the thickness of the eardrum and quantitative detection of underlying disease pathology, which could allow for more accurate diagnosis and more appropriate management than currently possible.

  18. Experimental study on magnetically insulated transmission line electrode surface evolution process under MA/cm current density

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, PengFei; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); State Key Laboratory of Intense Pulse Radiation of Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Hu, Yang; Yang, HaiLiang; Sun, Jiang; Wang, Liangping; Cong, Peitian [State Key Laboratory of Intense Pulse Radiation of Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-03-15

    The design of high-current density magnetically insulated transmission line (MITL) is a difficult problem of current large-scale Z-pinch device. In particular, a thorough understanding of the MITL electrode surface evolution process under high current density is lacking. On the “QiangGuang-I” accelerator, the load area possesses a low inductance short-circuit structure with a diameter of 2.85 mm at the cathode, and three reflux columns with a diameter of 3 mm and uniformly distributed circumference at the anode. The length of the high density MITL area is 20 mm. A laser interferometer is used to assess and analyze the state of the MITL cathode and anode gap, and their evolution process under high current density. Experimental results indicate that evident current loss is not observed in the current density area at pulse leading edge, and peak when the surface current density reaches MA/cm. Analysis on electrode surface working conditions indicates that when the current leading edge is at 71.5% of the peak, the total evaporation of MITL cathode structure can be realized by energy deposition caused by ohmic heating. The electrode state changes, and diffusion conditions are reflected in the laser interferometer image. The MITL cathode area mainly exists in metal vapor form. The metal vapor density in the cathode central region is higher than the upper limit of laser penetration density (∼4 × 10{sup 21}/cm{sup 3}), with an expansion velocity of ∼0.96 km/s. The metal vapor density in the electrode outer area may lead to evident distortion of fringes, and its expansion velocity is faster than that in the center area (1.53 km/s).

  19. Hyper-Transcranial Alternating Current Stimulation: Experimental Manipulation of Inter-Brain Synchrony

    Directory of Open Access Journals (Sweden)

    Caroline Szymanski

    2017-11-01

    Full Text Available We walk together, we watch together, we win together: Interpersonally coordinated actions are omnipresent in everyday life, yet the associated neural mechanisms are not well understood. Available evidence suggests that the synchronization of oscillatory activity across brains may provide a mechanism for the temporal alignment of actions between two or more individuals. In an attempt to provide a direct test of this hypothesis, we applied transcranial alternating current stimulation simultaneously to two individuals (hyper-tACS who were asked to drum in synchrony at a set pace. Thirty-eight female-female dyads performed the dyadic drumming in the course of 3 weeks under three different hyper-tACS stimulation conditions: same-phase-same-frequency; different-phase-different-frequency; sham. Based on available evidence and theoretical considerations, stimulation was applied over right frontal and parietal sites in the theta frequency range. We predicted that same-phase-same-frequency stimulation would improve interpersonal action coordination, expressed as the degree of synchrony in dyadic drumming, relative to the other two conditions. Contrary to expectations, both the same-phase-same-frequency and the different-phase-different-frequency conditions were associated with greater dyadic drumming asynchrony relative to the sham condition. No influence of hyper-tACS on behavioral performance was seen when participants were asked to drum separately in synchrony to a metronome. Individual and dyad preferred drumming tempo was also unaffected by hyper-tACS. We discuss limitations of the present version of the hyper-tACS paradigm, and suggest avenues for future research.

  20. Hyper-Transcranial Alternating Current Stimulation: Experimental Manipulation of Inter-Brain Synchrony.

    Science.gov (United States)

    Szymanski, Caroline; Müller, Viktor; Brick, Timothy R; von Oertzen, Timo; Lindenberger, Ulman

    2017-01-01

    We walk together, we watch together, we win together: Interpersonally coordinated actions are omnipresent in everyday life, yet the associated neural mechanisms are not well understood. Available evidence suggests that the synchronization of oscillatory activity across brains may provide a mechanism for the temporal alignment of actions between two or more individuals. In an attempt to provide a direct test of this hypothesis, we applied transcranial alternating current stimulation simultaneously to two individuals (hyper-tACS) who were asked to drum in synchrony at a set pace. Thirty-eight female-female dyads performed the dyadic drumming in the course of 3 weeks under three different hyper-tACS stimulation conditions: same-phase-same-frequency; different-phase-different-frequency; sham. Based on available evidence and theoretical considerations, stimulation was applied over right frontal and parietal sites in the theta frequency range. We predicted that same-phase-same-frequency stimulation would improve interpersonal action coordination, expressed as the degree of synchrony in dyadic drumming, relative to the other two conditions. Contrary to expectations, both the same-phase-same-frequency and the different-phase-different-frequency conditions were associated with greater dyadic drumming asynchrony relative to the sham condition. No influence of hyper-tACS on behavioral performance was seen when participants were asked to drum separately in synchrony to a metronome. Individual and dyad preferred drumming tempo was also unaffected by hyper-tACS. We discuss limitations of the present version of the hyper-tACS paradigm, and suggest avenues for future research.