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Sample records for current study investigated

  1. Investigation of scaling properties of a thin current sheet by means of particle trajectories study

    CERN Document Server

    Sasunov, Yu L; Alexeev, I I; Belenkaya, E S; Semenov, V S; Kubyshkin, I V; Mingalev, O V

    2015-01-01

    A thin current sheet (TCS), with the width of an order of thermal proton gyroradius, appears a fundamental physical object which plays an important role in structuring of major magnetospheric current systems (magnetotail, magnetodisk, etc.). The TCSs are nowadays under extensive study by means of space missions and theoretical models. We consider a simple model of the TCS separating two half-spaces occupied by a homogenous magnetic field of opposite sign tangential to the TCS; a small normal component of the magnetic field is prescribed. An analytical solution for the electric current and plasma density in the close vicinity of the TCS has been obtained and compared with numerical simulation. The number density and the electric current profiles have two maxima each. The characteristic spatial scale $z_S$ of the maxima location was investigated as a function of initial pitch-angle of an incoming charge particle. The effect of the thermal dispersion of the incoming proton beam have been taken into consideration...

  2. Investigation of Current Driven Loudspeakers

    DEFF Research Database (Denmark)

    Schneider, Henrik; Agerkvist, Finn T.; Knott, Arnold

    2015-01-01

    Current driven loudspeakers have previously been investigated but the literature is limited and the advantages and disadvantages are yet to be fully identified. This paper makes use of a non-linear loudspeaker model to analyse loudspeakers with distinct non-linear characteristics under voltage...... and current drive. A multi tone test signal is used in the evaluation of the driving schemes since it resembles audio signals to a higher degree than the signals used in total harmonic distortion and intermodulation distortion test methods. It is found that current drive is superior over voltage drive in a 5...

  3. Xerostomia: current streams of investigation.

    Science.gov (United States)

    Quock, Ryan L

    2016-07-01

    Xerostomia is the subjective feeling of dry mouth, and it is often related to salivary hypofunction. Besides medication-related salivary hypofunction, Sjögren syndrome and head-and-neck radiation are two common etiologies that have garnered considerable attention. Approaches to treating and/or preventing salivary hypofunction in patients with these conditions will likely incorporate gene therapy, stem cell therapy, and tissue engineering. Advances in these disciplines are central to current research in the cure for xerostomia and will be key to eventual treatment. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Current Automotive Holometry Studies

    Science.gov (United States)

    Marchi, Mitchell M.; Snyder, D. S.

    1990-04-01

    Holometry studies of automotive body and powertrain components have become a very useful high resolution test methodology to knowledgeable Ford engineering personnel. Current examples of studies that represent the static or dynamic operational conditions of the automotive test component are presented. Continuous wave laser holometry, computer aided holometry (CAH) and pulsed laser holometry were the holometric techniques used to study the following subjects: (1) body in prime (BIP) vibration modes, (2) transmission flexplate stud-torque converter deformation due to engine torque pulses, (3) engine cylinder head and camshaft support structure deformation due to cylinder pressure and (4) engine connecting rod/cap lift-off. Static and dynamic component loading and laboratory techniques required to produce usable and valid test results are discussed along with possible conclusions for the engineering concerns.

  5. Surface Morphology Study of Nanostructured Lead-Free Solder Alloy Sn-Ag-Cu Developed by Electrodeposition: Effect of Current Density Investigation

    Directory of Open Access Journals (Sweden)

    Sakinah Mohd Yusof

    2013-10-01

    Roman"; mso-bidi-theme-font:minor-bidi;} Doi: 10.12777/ijse.5.2.51-55 [How to cite this article: Yusof, S.M., Hadi, A., and Jai, J. (2013. Surface Morphology Study of Nanostructured Lead-Free Solder Alloy Sn-Ag-Cu Developed by Electrodeposition: Effect of Current Density Investigation. International Journal of Science and Engineering, 5(2:51-55. Doi: 10.12777/ijse.5.2.51-55 Current Care and Investigational Therapies in Achondroplasia.

    Science.gov (United States)

    Unger, Sheila; Bonafé, Luisa; Gouze, Elvire

    2017-04-01

    The goal of this review is to evaluate the management options for achondroplasia, the most common non-lethal skeletal dysplasia. This disease is characterized by short stature and a variety of complications, some of which can be quite severe. Despite several attempts to standardize care, there is still no widely accepted consensus. This is in part due to absence of concrete data on the incidence of sudden unexplained death in infants with achondroplasia and the best investigation for ascertaining which individuals could benefit from foramen magnum decompression surgery. In this review, we identify the different options of care and management for the various orthopedic, neurologic, and respiratory complications. In parallel, several innovative or drug repositioning therapies are being investigated that would restore bone growth but may also prevent complications. Achondroplasia is the most common non-lethal skeletal dysplasia. It is characterized by short stature and a variety of complications, some of which can be quite severe. Despite several attempts to standardize care, there is still no widely accepted consensus. This is in part due to absence of concrete data on the incidence of sudden unexplained death in infants with achondroplasia and the best investigation for ascertaining which individuals could benefit from foramen magnum decompression surgery. In this review, we identify the different options of care and management for the various orthopedic, neurologic, and respiratory complications. In parallel, several innovative or drug repositioning therapies are being investigated that would restore bone growth but may also prevent complications.

  6. Study of thermal-field emission properties and investigation of temperature dependent noise in the field emission current from vertical carbon nanotube emitters

    Science.gov (United States)

    Kolekar, Sadhu; Patole, S. P.; Patil, Sumati; Yoo, J. B.; Dharmadhikari, C. V.

    2017-10-01

    We have investigated temperature dependent field electron emission characteristics of vertical carbon nanotubes (CNTs). The generalized expression for electron emission from well-defined cathode surface is given by Millikan and Lauritsen [1] for the combination of temperature and electric field effect. The same expression has been used to explain the electron emission characteristics from vertical CNT emitters. Furthermore, this has been applied to explain the electron emission for different temperatures ranging from room temperature to 1500 K. The real-time field electron emission images at room temperature and 1500 K are recorded by using Charge Coupled Device (CCD) in order to understand the effect of temperature on distribution of electron emission spots and ring like structures in Field Emission Microscope (FEM) image. The FEM images could be used to calculate the total number of emitters per cm2 for electron emission. The calculated number of emitters per cm2 from FEM image is typically, 4.5 × 107 and the actual number emitters per cm2 present as per Atomic Force Microscopy (AFM) data is 1.2 × 1012. The measured Current-Voltage (I-V) characteristics exhibit non linear Folwer-Nordheim (F-N) type behavior. The fluctuations in the emission current were recorded at different temperatures and Fast Fourier transformed into temperature dependent power spectral density. The latter was found to obey power law relation S(f) = A(Iδ/fξ), where δ and ξ are temperature dependent current and frequency exponents respectively.

  7. Study of Thermal-Field Emission Properties and Investigation of Temperature dependent Noise in the Emission Current form vertical Carbon nanotube emitters

    KAUST Repository

    Kolekar, Sadhu

    2017-05-05

    We have investigated temperature dependent field electron emission characteristics of vertical carbon nanotubes (CNTs). The generalized expression for electron emission from well defined cathode surface is given by Millikan and Lauritsen [1] for the combination of temperature and electric field effect. The same expression has been used to explain the electron emission characteristics from vertical CNT emitters. Furthermore, this has been applied to explain the electron emission for different temperatures ranging from room temperature to 1500 K. The real-time field electron emission images at room temperature and 1500 K are recorded by using Charge Coupled Device (CCD), in order to understand the effect of temperature on electron emission spots in image morphology (as indicated by ring like structures) and electron emission spot intensity of the emitters. Moreover, the field electron emission images can be used to calculate the total number of emitters per cm2 for electron emission. The calculated number of emitters per cm2 is 4.5x107 and, the actual number emitters per cm2 present for electron emission calculated from Atomic Force Microscopy (AFM) data is 1.2x1012. The measured Current-Voltage (I-V) characteristics obey the Folwer-Nordheim (F-N) type behavior. The fluctuations in the emission current are recorded at different temperatures and, temperature dependence of power spectral density obeys power law relation s(f)=I2/f2 with that of emission current and frequency.

  8. Studies on the direct methanol fuel cell: Characterization of proton conducting polymer membranes and investigations of current distribution at the cathode

    Energy Technology Data Exchange (ETDEWEB)

    Saarinen, V.

    2007-07-01

    ), as over 2 000 h DMFC testing was carried out without any loss of performance. The methanol crossover and other mass transfer phenomena have been investigated in a free-breathing DMFC both experimentally and computationally. The information on local concentrations of the reacting species is obtained by measuring the current distribution profile using a resistor network approach and a segmented cathode. The developed numerical 3D model describes the behaviour of the free-breathing DMFC and gives spatial information on mass transfer phenomena, e.g. predicts the existence of the observed electrolytic domains, i.e. regions of negative current densities. (orig.)

  9. Investigations on contribution of glial inwardly-rectifying K+ current to membrane potential and ion flux: An experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Sheng-Nan Wu

    2015-01-01

    Full Text Available The inwardly rectifying K+ current [IK(IR] allows large inward K+ currents at potentials negative to K+ equilibrium potential (EK and it becomes small outward K+ currents at those positive to EK. How changes of such currents enriched in glial cells can influence the functions of glial cell, neurons, or both is not clearly defined, although mutations of Kir4.1 channels have been demonstrated to cause serious neurological disorders. In this study, we identified the presence of IK(IR in human glioma cells (U373 and U87 cells. The amplitude of IK(IR in U373 cells was subject to inhibition by amitriptyline, arecoline, or BaCl2. The activity of inwardly rectifying K+ channels was also clearly detected, and single-channel conductance of these channels was calculated to be around 23 pS. Moreover, based on a simulation model derived from neuron–glial interaction mediated by ion flux, we further found out that incorporation of glial IK(IR conductance into the model can significantly contribute to regulation of extracellular K+ concentrations and glial resting potential, particularly during high-frequency stimulation. Glial cells and neurons can mutually modulate their expression of ion channels through K+ ions released into the extracellular space. It is thus anticipated that glial IK(IR may be a potential target utilized to influence the activity of neuronal and glial cells as well as their interaction.

  10. INVESTIGATION OF BLOCKING ALGORITHM FOR TRANSFORMER CURRENT PROTECTIONS IN MAGNETIZING INRUSH CURRENT MODES

    Directory of Open Access Journals (Sweden)

    A. N. Kuzovlev

    2014-01-01

    Full Text Available Presents investigations on blocking  algorithm for transformer  current  protections  during magnetizing  inrush  current. The investigations have shown that the algorithm has high sensitivity and reliably determines magnetizing  inrush current modes.

  11. Experimental investigation of current free double layers in helicon plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, B. B. [Department of Applied Sciences and Humanities, Dronacharya College of Engineering, Gurgaon 123506 (India); Tarey, R. D. [Department of Physics, Indian Institute of Technology, New Delhi 110016 (India); Ganguli, A. [Centre for Energy Studies, Indian Institute of Technology, New Delhi 110016 (India)

    2014-02-15

    The paper presents investigations of current free double layer (CFDL) that forms in helicon plasmas. In contrast to the other work reporting on the same subject, in the present investigations the double layer (DL) forms in a mirror-like magnetic field topology. The RF compensated Langmuir probe measurements show multiple DLs, which are in connection with, the abrupt fall of densities along with potential drop of about 24 V and 18 V. The DLs strengths (e ΔV{sub p})/(k T{sub e}) are about 9.5 and 6, and the corresponding widths are about 6 and 5 D lengths. The potential drop is nearly equal to the thermal anisotropies between the two plasma regions forming the DL, which is present in the plateau region of mirror, unlike the earlier studies on the DL formation in the region of strong gradients in the magnetic field. Also, it presents a qualitative discussion on the mechanism of DL formation.

  12. Investigation study on current situation of dust management in coal enterprises%煤炭企业粉尘控制现状调查研究

    Institute of Scientific and Technical Information of China (English)

    范红敏; 崔炜; 袁聚祥; 陈银苹; 徐应军; 高雯

    2011-01-01

    To know the current situation of dust administration and control, and questions existed in the dust management in coal enterprises, so as to provide evidences for formulating the plan of prevention for coal workers' pneumonoconiosis. Subjects and Methods Five coal enterprises were selected as field studies by the typical sampling method. Some coal workers, occupational health personnel, dust prevention workers and dust monitor personnel were investigated by face to face questionaire and qualitative interview. Historical data were collected from the files of the five coal enterprises and pneumoconiosis diagnostic data. Database was set up in Epidata3.0, and the data were analyzed by SAS. Results With the time going, the proportion of category Ⅰ pneumoconiosis gradually increased. Subjects were very aware of the dust hazard and the necessity of the measure for dust prevention while they were not very familiar with the country's law for dust control, the right for worker's health, and the supervision for dust. Among 478 Investigated coal workers, only 59. 4% of people knew that firm had distributed propaganda materials. The using percentage of preventive material for the workers who exposed to dust directly was only 72. 6%,and the percentage for those who use preventive material each time was less than 50%. Bad comfort of using prevention material might be the main reasons to refuse the using among workers. 18.8% of employees still did not make pre-service medical examination. The devices for preventing dust were more perfect and went well, but there still had existed phenomenons that some dustproof facilities were not running. Conclusions There remained some questions that Dust hazard and dust prevention knowledge were lack of publicity, occupational health examination work was not integrity, dust control measures were inadequate, and the monitoring for the dust concentration might have some bugs. The corresponding measures have to be taken in the dust

  13. Current studies on megapode phylogeny

    NARCIS (Netherlands)

    Brom, T.G.; Dekker, R.W.R.J.

    1992-01-01

    Hypotheses regarding the phylogenetic relationships between megapodes and other birds are reviewed, and it is concluded that the available evidence supports a sistergroup relationship between megapodes and all other galliforms. Current studies in this direction are discussed. The resolvement of intr

  14. Summary of Tertiary investigations in western Saudi Arabia, current work by the U.S. Geological Survey and recommended future studies

    Science.gov (United States)

    Hadley, Donald G.; Schmidt, Dwight Lyman; Coleman, Robert Griffin

    1983-01-01

    In 1936, geologic work related to the Tertiary System in western Saudi Arabia began with a study of the Umm Gerad barite deposit by K. S. Twitchell. In 1944, a study focusing specifically on Tertiary rocks was conducted by Steineke and others near Jiddah. Small-scale mapping of Tertiary sequences began in 1950 in southwestern Saudi Arabia and later in northern 3audi Arabia as part of the Kingdom's early mapping program. These studies were part of a larger program being directed by the Government of Saudi Arabia in connection with mineral resource investigations. In the mid- to late-1960's, the Bureau de Recherches Geologiques et Minieres discovered mineralized Tertiary rocks al Jabal Dhaylan and began a study, which continues to the present, of both the Tertiary rocks and the mineralization. Following a number of early local studies, in 1973 the U.S. Geological Survey began detailed study of the Tertiary layered rocks along the Red Sea coastal plain south of Jiddah. More recently, Riofinex and Seltrust have been exploring for selected commodities in Tertiary sequences of northwestern Saudi Arabia and the Red Sea coastal plain. Results of these studies, including work by the Saudi Arabian Directorate General of Mineral Resources and the Saudi government agency preceding it, are summarized in this report. Characteristics of the Tertiary rocks south of lat 23? N. and the Tertiary mineral deposits of western Saudi Arabia are also summarized. Recommendations are made for future geologic studies and mineral assessment of the Tertiary rocks of western Saudi Arabia.

  15. Numeric Investigation of Brain Tumor Influence on the Current Distributions During Transcranial Direct Current Stimulation.

    Science.gov (United States)

    Song, Bo; Wen, Peng; Ahfock, Tony; Li, Yan

    2016-01-01

    This study constructed a series of high-resolution realistic human-head models with brain tumors, and numerically investigated the influence of brain tumor's location and grade on the current distributions, under different electrode montages during tDCS. The threshold area and the peak current density were also derived and analyzed in the region of interest. The simulation result showed that it is safe to apply tDCS on the patients with brain tumors to treat their neuropsychiatric conditions and cancer pain caused by the tumor; although considerable changes of the current distributions are induced by the presence of a brain tumor. In addition, several observations on the global and local influences of tumor grade and possible edema have been made as well. These findings should be helpful for researchers and clinical doctors to treat patients with brain tumors. This study is also the first numerical study to fill in the gap of tDCS applications on the patients with brain tumors.

  16. Experimental Investigation of Turbulence Specifications of Turbidity Currents

    Directory of Open Access Journals (Sweden)

    B Firoozabadi

    2010-01-01

    Full Text Available The present study investigates the turbulence characteristic of turbidity current experimentally. The three-dimensional Acoustic-Doppler Velocimeter (ADV was used to measure the instantaneous velocity and characteristics of the turbulent flow. The experiments were conducted in a three-dimensional channel for different discharge flows, concentrations, and bed slopes. Results are expressed at various distances from the inlet, for all flow rates, slopes and concentrations as the distribution of turbulence energy, Reynolds stress and the turbulent intensity. It was concluded that the maximum turbulence intensity happens in both the interface and near the wall. Also, it was observed that the turbulence intensity reaches its minimum where maximum velocity occurs.

  17. Experimental Setup for the Investigation of Superconducting Persistent Current

    Science.gov (United States)

    2015-09-01

    NOTES 14. ABSTRACT We report on a recent experimental setup for the investigation of the relaxation rate of the persistent current in an assembly of...at cryo-temperatures in magnetic field at time scale of seconds to hours. 15. SUBJECT TERMS persistent current, 2G HTS, coated conductor, relaxation ... activation . One unknown aspect is the variation of the coils’ position with temperature from room to cryogenic. A better design of the coils assembly

  18. [Current studies in myotonic dystrophy].

    Science.gov (United States)

    Zhao, Yimeng; Ishiura, Shoichi

    2014-03-01

    Myotonic dystrophy (DM) is a genetic, progressive, multisystemic disease with muscular disorder as its primary symptom. There are two types of DM (DM1 and DM2) caused by mutations in different genes, and in Japan, DM occurs with an incidence of approximately 1 in 20,000. The pathogenic mechanism underlying the disease is RNA toxicity caused by transcripts of aberrantly elongated CTG or CCTG repeats located in the 3' untranslated region or in the intron. The current treatments for DM is limited to symptomatic care. In this review, we will discuss several new therapeutic strategies based on recent studies of RNA toxicity.

  19. Investigation of casing inspection through tubing with pulsed eddy current

    Science.gov (United States)

    Fu, Yuewen; Yu, Runqiao; Peng, Xuewen; Ren, Shangkun

    2012-12-01

    Corrosion and cracks of casing string in oil wells is a serious problem on which little research has been done when inspecting casing through tubing. In this study, inspecting casing through tubing with pulsed eddy current is investigated. Longitudinal and transverse probes are centred inside the tubing to detect wall thinnings and cracks in casing. A time slice of induced voltage in the receiving coil of the probe is used as the feature to recognise defects. The experimental results show that large area wall thinnings and long cracks in casing are detected successfully through the tubing with appropriate inspection parameters. The probe's orientation to the crack is important and a particular discovery is that the transverse probe should be parallel to the transverse crack and not be perpendicular to it when inspecting. A method based on linear regression is proposed to estimate flaws in casing while wall thinning in the tubing occurs at the same location. The method is effective for large area thinning in casing when tubing thinning is wide.

  1. Investigation on a new inducer of pulsed eddy current thermography

    Science.gov (United States)

    He, Min; Zhang, Laibin; Zheng, Wenpei; Feng, Yijing

    2016-09-01

    In this paper, a new inducer of pulsed eddy current thermography (PECT) is presented. The use of the inducer can help avoid the problem of blocking the infrared (IR) camera's view in eddy current thermography technique. The inducer can also provide even heating of the test specimen. This paper is concerned with the temperature distribution law around the crack on a specimen when utilizing the new inducer. Firstly, relative mathematical models are provided. In the following section, eddy current distribution and temperature distribution around the crack are studied using the numerical simulation method. The best separation distance between the inducer and the specimen is also determined. Then, results of temperature distribution around the crack stimulated by the inducer are gained by experiments. Effect of current value on temperature rise is studied as well in the experiments. Based on temperature data, temperature features of the crack are discussed.

  2. Investigation on a new inducer of pulsed eddy current thermography

    Directory of Open Access Journals (Sweden)

    Min He

    2016-09-01

    Full Text Available In this paper, a new inducer of pulsed eddy current thermography (PECT is presented. The use of the inducer can help avoid the problem of blocking the infrared (IR camera’s view in eddy current thermography technique. The inducer can also provide even heating of the test specimen. This paper is concerned with the temperature distribution law around the crack on a specimen when utilizing the new inducer. Firstly, relative mathematical models are provided. In the following section, eddy current distribution and temperature distribution around the crack are studied using the numerical simulation method. The best separation distance between the inducer and the specimen is also determined. Then, results of temperature distribution around the crack stimulated by the inducer are gained by experiments. Effect of current value on temperature rise is studied as well in the experiments. Based on temperature data, temperature features of the crack are discussed.

  3. [Current status of autism studies].

    Science.gov (United States)

    Kurita, H

    2001-01-01

    The current status of autism studies was reviewed based on English articles published during the 1990s. Although the concepts of autism and pervasive developmental disorders (PDD) are established, diagnostic criteria of PDDNOS or atypical autism, which is frequently difficult to differentiate from autism, need to be established. The prevalence of autism has been estimated as about 0.05% in the U.S and many European countries, while it was reported to be 0.1% or higher in Japan and some European countries, though the reasons for this difference are unclear. High-functioning (IQ > or = 70) autism may not be as rare a condition as previously thought and both its difference from and similarity to Asperger's syndrome, the highest functioning PDD subtype, need clarification. About 20 to 40% of children with autism lose meaningful words by the age of 2 years and display autistic symptoms thereafter. Such autism, called the setback type in Japan, has been demonstrated to have a poorer adolescent/adult outcome compared to autism without setback and its relationship with childhood disintegrative disorder, which displays a clearer regression after normal development for at least the first 2 years of life, needs to be addressed. The etiology of autism is now considered mostly genetic for reasons, such as the significantly higher concordance rate of autism in identical twin pairs (60-80%) than in fraternal twin pairs (0-10%) and an 3-5% incidence of autism among sibs of an autism proband, 30 to 100 times higher than that in the general population. The involvement of several genes is implicated to create susceptibility for autism, yet the responsible genes have not been identified. Although there is no medication to cure autism, some psychotropic drugs, such as antipsychotics and SSRIs, seem effective for behavior problems in autism patients. Psychosocial treatments are the main therapeutic approach to autism, though they are yet to be well systematized. It is important to

  4. Investigation and Analysis of Current Writing Teaching Mode among English Majors in Normal Universities in China

    Science.gov (United States)

    Zeng, Hang-li

    2010-01-01

    This paper has made an investigation on the current writing teaching mode among English majors in normal universities in China, by means of questionnaire, interview and class observation. The study finds out that the current writing teaching mode is not purely product approach or process approach. In fact, the two approaches to writing co-exist in…

  5. Current investigations into carbon nanotubes for biomedical application

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoming; Fan Yubo [Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191 (China); Watari, Fumio, E-mail: x.m.li@hotmail.co [Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan)

    2010-04-15

    The nano-dimensionality of nature has logically given rise to the interest in using nanomaterials in the biomedical field. Currently, a lot of investigations into carbon nanotubes (CNTs), as one of the typical nanomaterials, are being made for biomedical application. In this review, five parts, such as cellular functions induced by CNTs, apatite formation on CNTs, CNT-based tissue engineering scaffold, functionalized CNTs for the delivery of genes and drugs and CNT-based biosensors, are stated, which might indicate that CNTs, with a range of unique properties, appear suited as a biomaterial and may become a useful tool for tissue engineering. However, everything has two parts and CNTs is not an exception. There are still concerns about cytotoxicity and biodegradation of CNTs. Chemical fictionalization may be one of the effective ways to improve the 'disadvantages' and utilize the 'advantages' of CNTs. One of their 'disadvantages', unbiodegradable property, may be utilized by creating monitors in in vivo-engineered tissues or nanosized CNT-based biosensors. Other promising research points, for example proteins adsorbed on CNTs, use of CNTs in combination with other biomaterials to achieve the goals of tissue engineering, mineralization of CNTs and standard toxicological tests for CNTs, are also described in the conclusion and perspectives part. (topical review)

  6. Investigation of Si(001) stable surfaces in alternating current heating

    Science.gov (United States)

    Doi, T.; Koguchi, M.

    2016-11-01

    The topography of a Si(001) vicinal surface is investigated using reflection electron microscopy (REM) during alternating current (AC) heating of the surface in ultra-high vacuum. The normal direction of the surface is slightly tilted from the [001] direction at θx or θy on the x or y axis (they are orthogonal directions in the Si(001) surface), and the average widths of the terraces (a or b in x or y axis) are determined by θx or θy; the direction perpendicular to the incidence electron beam on the surface is selected as the x (horizontal) axis in each REM image. Alternating current heating changes each initial surface from stable to double-domain (DD), in which 2 × 1 and 1 × 2 terraces are arranged regularly with approximately equal width, at its transition temperature Tc; the dimer rows are parallel to the x or y axis in the 1 × 2 or 2 × 1 terraces. There are two types of stable surfaces in the vicinal surface. At temperatures below its Tc, the surface with horizontally (vertically) long terraces, where b a), changes to a 2 × 1 (1 × 2) surface with wide 2 × 1 (1 × 2) and narrow 1 × 2 (2 × 1) terraces. The terrace, the short side of which is parallel to its dimer row direction, grows to create a stable surface by thermal diffusion of Si atoms at temperatures below Tc. During AC heating, thermal diffusion plays a key role in analyzing the kinetics of the atoms on the surface because the thermal effect acts as the driving force for the atoms that have not yet evaporated from the surface. Then, by evaporating atoms from the vicinal surface, AC heating creates a DD surface at temperatures between its Tc and 1100 °C and a rugged surface consisting of small 2 × 1 and 1 × 2 terraces at temperatures above 1100 °C.

  7. New Titan Saltation Threshold Experiments: Investigating Current and Past Climates

    Science.gov (United States)

    Bridges, N.; Burr, D. M.; Marshall, J.; Smith, J. K.; Emery, J. P.; Horst, S. M.; Nield, E.; Yu, X.

    2015-12-01

    Titan exhibits aeolian sand dunes that cover ~20% of its surface, attesting to significant sediment transport by the wind. Recent experiments in the Titan Wind Tunnel (TWT) at NASA Ames Research Center [1,2] found that the threshold friction speed needed to detach Titanian "sand" is about 50% higher than previous estimates based on theory alone [3], a result that might be explained by the low ratio of particle to fluid density on the body [1]. Following the successful completion of the initial Titan threshold tests, we are conducting new experiments that expand the pressure range above and below current Titan values. The basic experimental techniques are described in [1], with minor updates to the instrumentation as described in [2]. To reproduce the kinematic viscosity and particle friction Reynolds number equivalent to that expected for Titan's nitrogen atmosphere at 1.4 bars and 94 K requires that TWT be pressurized to 12.5 bars for air at 293K. In addition to running experiments at this pressure to reproduce previous results [1] and investigate low density (high density ratio) materials, TWT pressures of 3 and 8 bars are in the experimental matrix to understand threshold under past Titan conditions when the atmospheric pressure may have been lower [4]. Higher pressures, at 15 and 20 bars in TWT, are also being run to understand the putative effects of low density ratio conditions. Our experimental matrix for this follow-on work uses some of the same materials as previously used, including walnut shells, basalt, quartz, glass spheres, and various low density materials to better simulate the gravity-equivalent weight of Titan sand. For these experiments, the TWT is now equipped with a new high pressure Tavis transducer with sufficient sensitivity to measure freestream speeds of less than 0.5 m s-1 at 12.5 bars. New techniques include video documentation of the experiments. We are also investigating methods of measuring humidity of the wind tunnel environment and

  8. Current investigations into magnetic nanoparticles for biomedical applications.

    Science.gov (United States)

    Li, Xiaoming; Wei, Jianrong; Aifantis, Katerina E; Fan, Yubo; Feng, Qingling; Cui, Fu-Zhai; Watari, Fumio

    2016-05-01

    It is generally recognized that nanoparticles possess unique physicochemical properties that are largely different from those of conventional materials, specifically the electromagnetic properties of magnetic nanoparticles (MNPs). These properties have attracted many researchers to launch investigations into their potential biomedical applications, which have been reviewed in this article. First, common types of MNPs were briefly introduced. Then, the biomedical applications of MNPs were reviewed in seven parts: magnetic resonance imaging (MRI), cancer therapy, the delivery of drugs and genes, bone and dental repair, tissue engineering, biosensors, and in other aspects, which indicated that MNPs possess great potentials for many kinds of biomedical applications due to their unique properties. Although lots of achievements have been obtained, there is still a lot of work to do. New synthesis techniques and methods are still needed to develop the MNPs with satisfactory biocompatibility. More effective methods need to be exploited to prepare MNPs-based composites with fine microstructures and high biomedical performances. Other promising research points include the development of more appropriate techniques of experiments both in vitro and in vivo to detect and analyze the biocompatibility and cytotoxicity of MNPs and understand the possible influencing mechanism of the two properties. More comprehensive investigations into the diagnostic and therapeutic applications of composites containing MNPs with "core-shell" structure and deeper understanding and further study into the properties of MNPs to reveal their new biomedical applications, are also described in the conclusion and perspectives part.

  9. Investigating the Impacts of Previous and Current Learning Experiences on Student Teachers' Teaching Experiences

    Science.gov (United States)

    Ögeyik, Muhlise Cosgun

    2016-01-01

    This study investigated the impacts of the previous and current learning experiences of the student teachers on their microteaching practices. The study pursued threefold research goals: to diagnose the microteaching stance, to treat it, and to explore and evaluate the progress. The participants were 24 undergraduate third year student teachers…

  10. Participation in a trauma-focused epidemiological investigation may result in sensitization for current health problems

    NARCIS (Netherlands)

    Verschuur, M.J.; Spinhoven, Ph.; van Emmerik, A.A.P.; Rosendaal, F.R.

    2008-01-01

    Objectives - Participation in health survey research may result in a worsening of self-assessed health status and enhanced service-use by increasing self-awareness of current health status. The present study investigated whether participation in a traumafocused epidemiological study sensitized parti

  11. A Preliminary Investigation of Current Practices in American Youth Theatres.

    Science.gov (United States)

    Regan, F. Scott

    1983-01-01

    Summarizes results of a survey of youth theatres on (1) theatre goals; (2) staff training and courses offered; (3) organization and funds; and (4) teachers' knowledge of actor training, child and adolescent psychology, playwriting trends in children's theatre, and current theoretical writings. (PD)

  12. Walden Pond, Massachusetts: Environmental Setting and Current Investigations

    Science.gov (United States)

    Colman, John A.; Waldron, Marcus C.

    1998-01-01

    as plant nutrients, organic matter, and soil are leached and eroded from the surrounding watershed. This process is known as eutrophication. The term 'cultural eutrophication' refers to an accelerated form of the natural process in which extra soil and nutrients are derived from people's use of fertilizer, rerouting of surface drainage, and disposal of domestic and industrial waste. Cultural eutrophication can lead to excessive growth of aquatic plants, pond filling by decayed plants and eroded soils, reduced water clarity, and depletion of dissolved oxygen in deep water with subsequent loss of cold-water fish habitat. In order to document the longterm ecological health of Walden Pond, the U.S. Geological Survey (USGS), working in cooperation with the Massachusetts Department of Environmental Management (MDEM), is investigating factors that could contribute to cultural eutrophication of Walden. Through measurements of mass balance of nutrients and oxygen in the pond's deep water, the investigation will establish a baseline data set on Walden's trophic state, which is a measure of the pond's ability to support plant growth. The baseline data will be used to detect trends and give early warning of trophic changes or trophic response to pond remediation projects. This Fact Sheet provides background information on the environmental setting, limnological features, and cultural eutrophication of Walden Pond, and describes the joint USGS/MDEM study.

  13. Clinical comparison between a currently available single-loop and an investigational dual-channel endorectal receive coil for prostate magnetic resonance imaging: a feasibility study at 1.5 and 3 T.

    Science.gov (United States)

    Vos, Eline K; Sambandamurthy, Sriram; Kamel, Maged; McKenney, Robert; van Uden, Mark J; Hoeks, Caroline M A; Yakar, Derya; Scheenen, Tom W J; Fütterer, Jurgen J

    2014-01-01

    The objectives of this study were to test the feasibility of an investigational dual-channel next-generation endorectal coil (NG-ERC) in vivo, to quantitatively assess signal-to-noise ratio (SNR), and to get an impression of image quality compared with the current clinically available single-loop endorectal coil (ERC) for prostate magnetic resonance imaging at both 1.5 and 3 T. The study was approved by the institutional review board, and written informed consent was obtained from all patients. In total, 8 consecutive patients with prostate cancer underwent a local staging magnetic resonance examination with the successive use of both coils in 1 session (4 patients at 1.5 T and 4 other patients at 3 T). Quantitative comparison of both coils was performed for the apex, mid-gland and base levels at both field strengths by calculating SNR profiles in the axial plane on an imaginary line in the anteroposterior direction perpendicular to the coil surface. Two radiologists independently assessed the image quality of the T2-weighted and apparent diffusion coefficient maps calculated from diffusion-weighted imaging using a 5-point scale. Improvement of geometric distortion on diffusion-weighted imaging with the use of parallel imaging was explored. Statistical analysis included a paired Wilcoxon signed rank test for SNR and image quality evaluation as well as κ statistics for interobserver agreement. No adverse events were reported. The SNR was higher for the NG-ERC compared with the ERC up to a distance of approximately 40 mm from the surface of the coil at 1.5 T (P coils were comparable. Overall, T2-weighted image quality was considered better for NG-ERC at both field strengths. Quality of apparent diffusion coefficient maps with the use of parallel imaging was rated superior with the NG-ERC at 3 T. The investigational NG-ERC for prostate imaging outperforms the current clinically available ERC in terms of SNR and is feasible for continued development for future use as

  14. Study of longshore current equations for currents in Visakhapatnam beach

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Rao, T.V.N.

    Longshore currents were measured along the Visakhapatnam Beach, Andhra Pradesh, India at weekly intervals from March 1978 to March 1979. Visual observations on breaker characteristics were also made during this period. Using modified Longuet...

  15. Studies of Current Dependent Effects at ANKA

    CERN Document Server

    Müller, A S; Huttel, E; Pérez, F; Pont, M; Zimmermann, Frank

    2004-01-01

    The ANKA electron storage ring is operated at energies between 0.5 and 2.5 GeV. A major requirement for a synchrotron light source, such as ANKA, is to achieve a high beam current. A multitude of mostly impedance related effects depend on either bunch or total beam current. This paper gives an overview over the various beam studies performed at ANKA in this context, specifically the observation of current dependent detuning, the determination of the bunch length change with current from a measurement of the ratio between coherent and incoherent synchrotron tune and an assessment of the effective longitudinal loss factor from the current dependent horizontal closed orbit distortion.

  16. Current investigation and management of patients with syncope

    DEFF Research Database (Denmark)

    Dagres, Nikolaos; Bongiorni, Maria Grazia; Dobreanu, Dan

    2013-01-01

    for neurally mediated syncope. Physical manoeuvres were the most widely (93%) applied standard treatment for this syncope form. The results of this survey suggest that there are significant differences in the management of patients with syncope across Europe, specifically with respect to hospitalization rates......The aim of this European Heart Rhythm Association (EHRA) survey was to provide an insight into the current practice of work-up and management of patients with syncope among members of the EHRA electrophysiology research network. Responses were received from 43 centres. The majority of respondents...... (74%) had no specific syncope unit and only 42% used a standardized assessment protocol or algorithm. Hospitalization rates varied from 10% to 25% (56% of the centres) to >50% (21% of the centres). The leading reasons for hospitalization were features suggesting arrhythmogenic syncope (85...

  17. Investigation of heavy current discharges with high initial gas density

    Energy Technology Data Exchange (ETDEWEB)

    Budin, A.; Bogomaz, A.; Kolikov, V.; Kuprin, A.; Leontiev, V.; Rutberg, P.; Shirokov, N. [Institute of Problems of Electrophysics of Russian Academy of Sciences, Dvortsovayanab., 18, St. Petersburg, 191065 (Russia)

    1996-05-01

    Piezoelectric pressure transducers, with noise immunity and time resolution of 0,5 {mu}s were used to measure pulse pressures of 430 MPa along the axis of an electrical discharge channel. Initial concentration of He was 2,7{center_dot}10{sup 21}cm{sup {minus}3}, dI/dt=6{center_dot}10{sup 11}A/s, and I{sub max}=560kA. Shock waves with amplitudes exceeding the pressure along the axis, were detected by a pressure transducer on the wall of the discharge chamber. Typical shock velocities were 2{center_dot}4km/s. Average pressure measurements along the discharge axis at different radii were used to estimate the current density distribution along the canal radius. The presence of the shock waves, promoting the additional hydrogen heating in the discharge chamber, has been registered during the discharge in hydrogen for I{sub max}{approximately}1MA and an initial concentration of 10{sup 21}cm{sup {minus}3}. {copyright} {ital 1996 American Institute of Physics.}

  18. An Investigation of Current Endodontic Practice in Turkey

    Directory of Open Access Journals (Sweden)

    R. F. Kaptan

    2012-01-01

    Full Text Available Objectives. The aim of this study was to gather information about the quality and quantity of root canal treatments carried out by general dental practitioners in Turkey. Methods. Questionnaires were given to 1400 dentists who attended the 16th National Congress organized by the Turkish Dental Association. The participants were asked to answer 34 multiple-choice questions. The questions were subdivided into 3 main topics; general information; general approach to endodontic treatment; and cleaning, shaping, and obturation of root canals. The statistical analysis was carried out by an -test to compare the means at a significance level of . Results. The response rate for this study was 43%. There was a wide variation in the number of root canal treatments completed per month. Nearly 92% of practitioners stated that they never used rubber dam. The most commonly used working length determination technique was radiographic evaluation (. Sodium hypochlorite was the irrigant of choice with varying concentrations and AH Plus was the sealer of choice (. Resin composite was the most frequently used material for final restorations. Conclusions. Endodontic procedures in general practice in Turkey have differences from widely acknowledged quality guidelines. Despite the introduction of new instruments and techniques, most of the general practitioners chose conventional methods.

  19. An Investigation of Current Endodontic Practice in Turkey

    Science.gov (United States)

    Kaptan, R. F.; Haznedaroglu, F.; Kayahan, M. B.; Basturk, F. B.

    2012-01-01

    Objectives. The aim of this study was to gather information about the quality and quantity of root canal treatments carried out by general dental practitioners in Turkey. Methods. Questionnaires were given to 1400 dentists who attended the 16th National Congress organized by the Turkish Dental Association. The participants were asked to answer 34 multiple-choice questions. The questions were subdivided into 3 main topics; general information; general approach to endodontic treatment; and cleaning, shaping, and obturation of root canals. The statistical analysis was carried out by an χ 2-test to compare the means at a significance level of P Endodontic procedures in general practice in Turkey have differences from widely acknowledged quality guidelines. Despite the introduction of new instruments and techniques, most of the general practitioners chose conventional methods. PMID:23251103

  20. Multiscale Study of Currents Affected by Topography

    Science.gov (United States)

    2015-09-30

    boundary layers to influence the ambient larger-scale flow. We have studied these issues through ocean model simulations, adjoint sensitivity...circulation be monitored from pressure gauges, temperature sensors, current meters, or other measurements near the feature? • The influence of the

  1. Simulation and investigation of SiPM’s leakage currents at low voltages

    Science.gov (United States)

    Parygin, P. P.; Popova, E. V.; Grachev, V. M.

    2017-01-01

    Technology Computer-Aided Design (TCAD) allows us to use computers in order to develop semiconductor processing technologies and devices and optimize them. Within a framework of a study of silicon photomultipliers (SiPM) a simulation of these devices has been made. The simulation was performed for the irradiated SiPMs and current-voltage characteristics were obtained for the modeled devices. Investigation of current-voltage curve below breakdown with regard to the simulated structure was performed. Obtained curves are presented.

  2. The ENIQ pilot study: current status

    Energy Technology Data Exchange (ETDEWEB)

    Lemaitre, P.; Eriksen, B.; Crutzen, S. [European Commission, DG Joint Research Centre, Petten (Netherlands); Hansch, M. [Preussische Elektrizitaets-AG (Preussenelektra), Hannover (Germany); Whittle, J. [AEA Technology, Warrington (United Kingdom)

    1998-11-01

    A pilot study is currently being carried out by ENIQ (European Network for Inspection Qualification) in order to explore the issues involved in inspection qualification applied along the general principles of the European methodology. The components selected for the pilot study are austenitic pipe to pipe and pipe to elbows welds typical of those in BWR recirculation loops. A range of defect parameters has been defined. A suitable inspection procedure designed to find the designated defects will be applied to geometrically representative test pieces. The procedure/equipment will be qualified through open trials and technical justification. The personnel qualification will be done in a blind way. Once all features of the inspection system will have been qualified an in-service inspection will be simulated in order to test the feasibility of the qualification approach followed. In this paper the current status of this pilot study is discussed. (orig.)

  3. INVESTIGATION OF MICROPROCESSOR TRANSFORMER CURRENT PROTECTION IN SHORT CIRCUIT FAULT MODES

    Directory of Open Access Journals (Sweden)

    M. S. Loman

    2014-01-01

    Full Text Available The paper presents an investigation on transformer current protection with blocking against magnetizing inrush current in short circuit fault modes. It has been shown that the proposed magnetizing in-rush current blocking algorithm can be implemented in microprocessor current protections of transformers.

  4. [Current registry studies of acute ischemic stroke].

    Science.gov (United States)

    Veltkamp, R; Jüttler, E; Pfefferkorn, T; Purrucker, J; Ringleb, P

    2012-10-01

    Study registries offer the opportunity to evaluate the effects of new therapies or to observe the consequences of new treatments in clinical practice. The SITS-MOST registry confirmed the validity of findings from randomized trials on intravenous thrombolysis concerning safety and efficacy in the clinical routine. Current study registries concerning new interventional thrombectomy techniques suggest a high recanalization rate; however, the clinical benefit can only be evaluated in randomized, controlled trials. Similarly, the experiences of the BASICS registry on basilar artery occlusion have led to the initiation of a controlled trial. The benefit of hemicraniectomy in malignant middle cerebral artery infarction has been demonstrated by the pooled analysis of three randomized trials. Numerous relevant aspects are currently documented in the DESTINY-R registry. Finally, the recently started RASUNOA registry examines diagnostic and therapeutic aspects of ischemic and hemorrhagic stroke occurring during therapy with new oral anticoagulants.

  5. A Study to Compare the Failure Rates of Current Space Shuttle Ground Support Equipment with the New Pathfinder Equipment and Investigate the Effect that the Proposed GSE Infrastructure Upgrade Might Have to Reduce GSE Infrastructure Failures

    Science.gov (United States)

    Kennedy, Barbara J.

    2004-01-01

    The purposes of this study are to compare the current Space Shuttle Ground Support Equipment (GSE) infrastructure with the proposed GSE infrastructure upgrade modification. The methodology will include analyzing the first prototype installation equipment at Launch PAD B called the "Pathfinder". This study will begin by comparing the failure rate of the current components associated with the "Hardware interface module (HIM)" at the Kennedy Space Center to the failure rate of the neW Pathfinder components. Quantitative data will be gathered specifically on HIM components and the PAD B Hypergolic Fuel facility and Hypergolic Oxidizer facility areas which has the upgraded pathfinder equipment installed. The proposed upgrades include utilizing industrial controlled modules, software, and a fiber optic network. The results of this study provide evidence that there is a significant difference in the failure rates of the two studied infrastructure equipment components. There is also evidence that the support staff for each infrastructure system is not equal. A recommendation to continue with future upgrades is based on a significant reduction of failures in the new' installed ground system components.

  6. Subminiature eddy current transducers for studying boride coatings

    Science.gov (United States)

    Dmitriev, S. F.; Ishkov, A. V.; Malikov, V. N.; Sagalakov, A. M.

    2016-07-01

    Strengthening of parts and units of machines, increased reliability and longer service life is an important task of modern mechanical engineering. The main objects of study in the work were selected steel 65G and 50HGA, wear-resistant boride coatings ternary system Fe-B-Fe n B which were investigated by scanning electron microscopy and eddy-current nondestructive methods.

  7. Laboratory Investigations of Current Sheets at the Electron Skin Depth Scale

    Science.gov (United States)

    Vincena, S.; Gekelman, W.

    2005-12-01

    Laboratory Investigations of Current Sheets at the Electron Skin Depth Scale. Theoretical investigations, in situ spacecraft and rocket missions, and laboratory studies form an essential triad for understanding the variety of current sheet phenomena found in space plasmas. In the Large Plasma Device (LAPD) at UCLA, the formation dynamics, equilibrium state, and wave-mediated disruptions of current sheets can be studied with great spatial and temporal resolution using a variety of probes as well as non-invasive laser induced fluorescence and other optical diagnostics. The LAPD is aptly suited for studying current sheets flowing in a magnetized background plasma which is capable of supporting Alfvén waves. The cylindrical device is 20m long and one meter in diameter with a solenoidal magnetic field as high as 3000 Gauss. For the parameters in this experiment, the plasma column is ten shear Alfvén wavelengths along the field and 100 electron inertial lengths (δe) (or 200 ρi) in the perpendicular direction. An electron current sheet is created in the plasma by placing a thin copper plate in the plasma column at one end of the device and pulsing this plate positive with respect to the chamber wall. The current sheet extends for the length of the device and has an initial cross-field size of roughly 45 δe by 0.5δe. A parallel flow of ions is observed with similar dimensions and moves in the same direction as the electrons in the current sheet with a velocity of 0.2 times the ion sound speed. A much weaker sheared perpendicular flow is also measured. Cross-sections of the ion flow are measured at several axial locations over a distance of six meters. Second, as the ion flow increases in magnitude, a much broader (8ρi) density depletion (n=0.25nO) develops around the flow. The gradient scale length of the depletion shortens until the spontaneous growth of drift waves occurs. This disrupts the electron current and ion flow, and leads to cross-field transport of

  8. A study of model bivalve siphonal currents

    Science.gov (United States)

    Monismith, Stephen G.; Koseff, Jeffrey R.; Thompson, Janet K.; O'Riordan, Catherine A.; Nepf, Heidi M.

    1990-01-01

    We carried out experiments studying the hydrodynamics of bivalve siphonal currents in a laboratory flume. Rather than use living animals, we devised a simple, model siphon pair connected to a pump. Fluorescence-based flow visualization was used to characterize siphon-jet flows for several geometric configurations and flow speeds. These measurements show that the boundary-layer velocity profile, siphon height, siphon pair orientation, and size of siphon structure all affect the vertical distribution of the excurrent flow downstream of the siphon pair and the fraction of excurrent that is refiltered. The observed flows may effect both the clearance rate of an entire population of siphonate bivalves as well as the efficiency of feeding of any individual. Our results imply that field conditions are properly represented in laboratory flume studies of phytoplankton biomass losses to benthic bivalves when the shear velocity and bottom roughness are matched to values found in the field. Numerical models of feeding by a bivalve population should include an effective sink distribution which is created by the combined incurrent-excurrent flow field. Near-bed flows need to be accounted for to properly represent these benthic-pelagic exchanges. We also present velocity measurements made with a laser-Doppler anemometer (LDA) for a single configuration (siphons flush with bed, inlet downstream) that show that the siphonal currents have a significant local effect on the properties of a turbulent boundary layer.

  9. Corrosion investigations, Tracy Red Bluff, California, and Boulder City, Nevada, ehv direct current tests

    Energy Technology Data Exchange (ETDEWEB)

    Backstrom, T.E.

    1965-01-01

    Evaluation of corrosion on buried metalwork, by the introduction of large direct currents into the ground, was studied during ehv dc transmission investigations in the Tracy-Red Bluff, California and the Boulder City, Nevada areas. Tests made on two types of electrodes showed that ehv dc ground return at test current levels would: (1) promote serious corrosion of buried metalwork within approximately 1/2-mile radius of the electrode with a ground mat electrode and mild corrosion with a deep-well electrode; (2) promote negligible-to-serious corrosion of buried pipelines within 1/2 to 3 mile radius of either a ground mat or deep-well electrode, depending on (a) distance of the pipelines from the electrode, (b) geometry of the two electrode-pipeline systems, and (c) horizontal extent of the pipelines; (3) impress negligible-to-mild corrosion of buried pipelines beyond a 3-mile radius of the electrode depending upon geometry of the electrode-pipeline system. Results show normal corrosion prevention techniques will be adequate to prevent corrosion of buried metalwork, if electrode is properly located. Use of ground return for only 8 to 24 hours per year on the ehv intertie, although with currents 2 to 3 times higher than test currents, will cause stray current damage of only a fraction of that expected with continuous operations.

  10. A western boundary current eddy characterisation study

    Science.gov (United States)

    Ribbe, Joachim; Brieva, Daniel

    2016-12-01

    The analysis of an eddy census for the East Australian Current (EAC) region yielded a total of 497 individual short-lived (7-28 days) cyclonic and anticyclonic eddies for the period 1993 to 2015. This was an average of about 23 eddies per year. 41% of the tracked individual cyclonic and anticyclonic eddies were detected off southeast Queensland between about 25 °S and 29 °S. This is the region where the flow of the EAC intensifies forming a swift western boundary current that impinges near Fraser Island on the continental shelf. This zone was also identified as having a maximum in detected short-lived cyclonic eddies. A total of 94 (43%) individual cyclonic eddies or about 4-5 per year were tracked in this region. The census found that these potentially displaced entrained water by about 115 km with an average displacement speed of about 4 km per day. Cyclonic eddies were likely to contribute to establishing an on-shelf longshore northerly flow forming the western branch of the Fraser Island Gyre and possibly presented an important cross-shelf transport process in the life cycle of temperate fish species of the EAC domain. In-situ observations near western boundary currents previously documented the entrainment, off-shelf transport and export of near shore water, nutrients, sediments, fish larvae and the renewal of inner shelf water due to short-lived eddies. This study found that these cyclonic eddies potentially play an important off-shelf transport process off the central east Australian coast.

  11. The investigation of reverse traction current influence on tone track circuit modes

    Directory of Open Access Journals (Sweden)

    E.I.Jasсhuk

    2012-12-01

    Full Text Available Introduction: With the introduction of high-speed traffic there is an increased consumption of traction current by new types of rolling stock. This issue is important, as high levels of traction currents can have not only prevents, but also a dangerous impact on the equipment of railway automation devices. It is necessary to investigate the propagation of traction currents and potentials along the rails. Objective: Investigate the propagation of traction currents and potentials along the rails, the determination of critical currents, which not executed tone track circuits modes. Methods: In order to investigate the mathematical model, and the method of calculation tone track circuits modes was used. Results: By means of mathematical model, which includes being several rolling-stocks at the feeder zone, different rail resistance and isolation, the diagrams of currents and potentials propagations for DC and AC electric traction have been obtained. A comparative analysis of the experimental data and the results of the investigation has been realized. Based on received levels of reverse traction current their influence on track circuit modes has been investigated. Conclusions: The reverse traction current level near the substation and rolling-stock can be more than 600A. Great reverse traction current levels have an influence on tonal track circuit functioning, namely normal and shunt modes. When the traction current arrives 200 A there is a reduction criteria of tonal track circuits.

  12. Investigating Effects of Nano- to Micro-Ampere Alternating Current Stimulation on Trichophyton rubrum Growth

    Science.gov (United States)

    Kwon, Dong Rak; Kwon, Hyunjung; Lee, Woo Ram

    2016-01-01

    Background Fungi are eukaryotic microorganisms including yeast and molds. Many studies have focused on modifying bacterial growth, but few on fungal growth. Microcurrent electricity may stimulate fungal growth. Objective This study aims to investigate effects of microcurrent electric stimulation on Trichophyton rubrum growth. Methods Standard-sized inoculums of T. rubrum derived from a spore suspension were applied to potato dextrose cornmeal agar (PDACC) plates, gently withdrawn with a sterile pipette, and were applied to twelve PDACC plates with a sterile spreader. Twelve Petri dishes were divided into four groups. The given amperage of electric current was 500 nA, 2 µA, and 4 µA in groups A, B, and C, respectively. No electric current was given in group D. Results In the first 48 hours, colonies only appeared in groups A and B (500 nA and 2 µA exposure). Colonies in group A (500 nA) were denser. Group C (4 µA) plates showed a barely visible film of fungus after 96 hours of incubation. Fungal growth became visible after 144 hours in the control group. Conclusion Lower intensities of electric current caused faster fungal growth within the amperage range used in this study. Based on these results, further studies with a larger sample size, various fungal species, and various intensities of electric stimulation should be conducted. PMID:27746636

  13. 龙狮运动市场化运营现状调查研究%Investigation and Study of Current Marketization Operation Situation of Chinese Dragon and Lion Dance

    Institute of Scientific and Technical Information of China (English)

    张伟伟; 李晓呜; 林劲杨

    2012-01-01

    With the methodd of literature, expert interview, survey, mathematical statistics, induction and deduction and other research methods, the paper studies the current conditions and the influencing factor of Chinese dragon and lion dance, the long-term planning and countermeasures of Chinese dragon and lion dance Association's development trend. On the current conditions of Chinese dragon and lion dance, attention of the government, public participation, social support, frequent events and activities organized, all these gradually increase have taken shape, they became drive national dragon lion movement development leader and lever, and play a positive role for the promotion and development of Chinese dragon and lion dance.%文章运用文献资料法、专家访谈法、调查法、数理统计、归纳演绎法等研究方法,对龙狮运动发展的现状和影响因素,以及龙狮运动协会的发展趋势进行长远规划与对策研究;,就龙狮运动目前发展而言,政府的重视、群众的参与、社会的支持、赛事活动的频繁举办并逐渐增加的局面已经形成,成为带动全国龙狮运动发展的龙头和杠杆,为龙狮运动的推广和发展发挥了积极的作用。

  14. Investigation of properties of human epidermal membrane under constant conductance alternating current iontophoresis.

    Science.gov (United States)

    Zhu, Honggang; Peck, Kendall D; Miller, David J; Liddell, Mark R; Yan, Guang; Higuchi, William I; Li, S Kevin

    2003-04-14

    Previous studies in our laboratory have shown that enhanced, constant permeant fluxes across human skin can be achieved by applying an alternating current (AC) to maintain skin electrical conductance at a constant level. Relative to conventional direct current (DC) iontophoresis, for which current is maintained at a constant level, this newly developed constant conductance alternating current (CCAC) method achieves constant fluxes with less inter- and intra-sample variability. The present study focused upon further investigating the permeability properties of human skin during CCAC iontophoresis at a variety of target resistance/conductance values. A three-stage experimental protocol was used with flux measurements determined on 3 consecutive days. Stage I was an AC only protocol (symmetrical AC square-wave signal), stage II was an AC plus DC protocol (AC square-wave with DC offset voltage), and stage III was a repeat of stage I. During this three-stage protocol, the skin electrical resistance was maintained at a constant target value by manually adjusting the applied AC voltage. Radiolabeled mannitol and urea were model permeants in all experiments. Their fluxes were determined and used to characterize the permeability properties of human skin. The results from the present study established that: (i) the CCAC protocol made it possible to reduce HEM electrical resistance to different target levels as low as 0.8 kOmega cm(2) and maintain the specific resistance level throughout the flux experiment, (ii) permeant fluxes are proportional to skin electrical conductance, (iii) under the studied CCAC passive conditions, membrane pore size tends to increase as skin resistance decreases, and (iv) as the membrane breaks down, its pore sizes become larger.

  15. Recent Advances in Studies of Current Noise

    Science.gov (United States)

    Blanter, Yaroslav M.

    This is a brief review of recent activities in the field of current noise intended for newcomers. We first briefly discuss main properties of shot noise in nanostructures, and then turn to recent developments, concentrating on issues related to experimental progress: non-symmetrized cumulants and quantum noise; counting statistics; super-Poissonian noise; current noise and interferometry

  16. Investigation of the characteristics of GIDL current in 90nm CMOS technology

    Institute of Scientific and Technical Information of China (English)

    Chen Hai-Feng; Hao Yue; Ma Xiao-Hua; Zhang Jin-Cheng; Li Kang; Cao Yan-Rong; Zhang Jin-Feng; Zhou Peng-Ju

    2006-01-01

    A specially designed experiment is performed for investigating gate-induced drain leakage (GIDL) current in 90nm CMOS technology using lightly-doped drain (LDD) NMOSFET. This paper shows that the drain bias VD has a strong effect on GIDL current as compared with the gate bias VG at the same drain-gate voltage VDG-It is found that the difference between ID in the off-state ID-VG characteristics and the corresponding one in the off-state ID-VD characteristics, which is defined as /DIFF, versus VDG shows a peak. The difference between the influences of VD and VG on GIDL current is shown quantitatively by /DIFF, especially in 90nm scale. The difference is due to different hole tunnellings. Furthermore, the maximum /DIFF(IDIFF.MAX) varies linearly with VDG in logarithmic coordinates and also VDG at IDIFF.MAX with VF which is the characteristic voltage of /DIFF- The relations are studied and some related expressions are given.

  17. Sounding Rocket Experiments to Investigate Thermal Electron Heating in the Sq Current Focus

    Science.gov (United States)

    Abe, T.; Ishisaka, K.; Kumamoto, A.; Yoshikawa, A.; Takahashi, T.; Tanaka, M.

    2015-12-01

    Sounding rocket observations in the southern part of Japan suggest that the electron temperature profile occasionally exhibits the local increase by several hundred K at 100-110 km altitudes at 1100-1200 LT in winter. Detailed study of the temperature profiles indicates that such an increase is closely related to the existence of Sq current focus, because it becomes more significant when the measurement is made near the center of Sq focus. In order to understand a general feature of this unusual phenomena occurring in the Sq current focus, the sounding rocket experiment was conducted in Uchinoura of Japan. In this experiment, we launched "S-310-37" rocket equipped with a total of eight science instruments at 11:20 JST on January 16, 2007 after being convinced that the Sq current was approaching to the planned rocket trajectory. The geomagnetic activity had been successively quiet on that day so that we can estimate the position of Sq current focus. Our analysis of the obtained data indicates that the electron temperature was certainly increased by about 500-600 K at the altitude of 97-101 km with respect to the background. Strong electron density perturbation was also observed to exist above 97 km altitude, which corresponds to the lower boundary of the high electron temperatures. It is also noticeable that both the electric field and magnetic field data include unusual variation in the same altitude region as the temperature increase was observed, suggesting a possible connection between the thermal electron heating and variation of the electric and/or magnetic field. Thus, the first experiment in 2007 revealed a general feature of such unusual phenomena in the Sq current focus, and thereby our interest to the generation mechanism for increasing the electron temperature was more and more increased. We will conduct the second rocket experiment to investigate such unusual phenomena in the Sq current focus in January 2016. In this experiment, we will try to measure

  18. The Current Canon in British Romantics Studies.

    Science.gov (United States)

    Linkin, Harriet Kramer

    1991-01-01

    Describes and reports on a survey of 164 U.S. universities to ascertain what is taught as the current canon of British Romantic literature. Asserts that the canon may now include Mary Shelley with the former standard six major male Romantic poets, indicating a significant emergence of a feminist perspective on British Romanticism in the classroom.…

  19. Experimental Investigation and Modelling for the Optimisation of Conduction Cooled HTS Hybrid Current Leads for SMES

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    It′s important that HTS tapes have lower thermal conductivity and higher transversal resistivity in order to reduce the heat leaks conducted along the tapes and AC losses in the high temperature superconducting system conduction-cooled by GM coolers. This paper presents an experimental investigation into the effects of pure Ag and AgAu alloys sheath materials on the properties of Bi(2223) multifilamentary tapes and the optimisation of conduction-cooled hybrid current leads made from copper and Bi(2223)/Ag or Bi(2223)/AgAu tapes. The thermal conductivity of the tapes were measured by cryogenic steady heat flux method and the resistance was measured by using standard DC four-probe method at low temperature. The results showed that the reduction of thermal conductivity by the addition of Au into the sheath material of Bi(2223) tapes was 650%, 750% and 850% lower than that of pure Ag sheathed Bi(2223) tapes and the increase of resistivity was 4.9, 10 and 19.4 times higher than that of pure Ag for the addition of 2.20%, 5.70% and 10.70%Au(atom ratio) respectively. And the study also attempts to optimise thermodynamically the conduction-cooled hybrid current lead by using a developed model, which took the irreversibility of commercial GM coolers, the contact resistance and thermal conductance into account. Predictions from the model showed that AgAu alloys were suitable candidate materials to replace Ag as sheath material of Bi(2223) tapes applied in HTS current leads. In addition, Bi(2223)/AgAu was a suitable material to be applied as the HTS section of hybrid current leads in conduction-cooled superconducting electric systems.

  20. AN EMPIRICAL STUDY OF CURRENT RATIO

    Directory of Open Access Journals (Sweden)

    Atanas Delev

    2014-10-01

    Full Text Available This work aims to address problems of liquidity and in particular the values and factors that influenced the values of the coefficient of total liquidity sixty Bulgarian public companies for the period 2013 - 2007 year. In the analysis it was found that some businesses fail to achieve favorable values of the ratio between current assets and current liabilities. It was found that plants have a low level of total liquidity, which can create problems in repayment of short-term liabilities. It can be seen that there are companies with very high liquidity, which is not so good phenomenon, ie the retention of a high level of resources required. Businesses should conduct a thorough analysis and implement appropriate measures to correct adverse changes. The financial management of the companies surveyed had worked towards improving the state of the enterprise, thereby seeking to reduce liquidity risk.

  1. The causal relationship between Foreign Direct Investment and Current Account: an empirical investigation for Pakistan economy

    Directory of Open Access Journals (Sweden)

    Muhammad ASIM

    2013-08-01

    Full Text Available This paper investigates relationship between FDI and current account (CA in Pakistan using the Johansen-Juselius cointegration technique and the Granger causality test. The study results indicate that FDI and CA are cointegrated and thus exhibit a reliable long run relationship. The Granger causality test findings indicate that the causality between FDI and CA is uni-directional. However, there is no short run causality from FDI to CA and vice versa. Therefore, as a policy implication that FDI inflows may cause to the deterioration of the balance of payments in the long run should be taken into account when policy makers decide to implement policies to attract foreign investors.

  2. An Investigation on the Current Situation of Management Information Systems Discipline in Turkey

    Directory of Open Access Journals (Sweden)

    Serdar YARLIKAŞ

    2015-09-01

    Full Text Available The purpose of this research is to investigate the development of management information systems field by evaluating the theses conducted at universities in Turkey in the departments of management information systems and science of management information systems. First, this study aims to determine the distribution of the theses in terms of years, subjects and the research methods used. Another purpose of this study was to determine which of the related disciplines of management information systems are used most in the theses. In addition, as a result of the study, the compatibility degree between the theses written and the courses taught in the graduate programs of management information systems were determined. In this research, content analysis method is used. Through this method, each of the theses was evaluated with a 10-question ‘thesis evaluation question set' constructed towards the purpose of the study. Through this evaluation, the current situation of the field was determined. It was observed that the number of doctoral theses associated with the field was less. Using the combination of qualitative and quantitative techniques most in the theses denoted that the interdisciplinary approaches were adopted in the theses associated with management information systems. It was observed that the literature analysis and survey techniques were the most studied research methods in the theses. Besides, statistical techniques were used highly in the theses. As a result of this study, it was concluded that out of the associated disciplines of management information systems, management science, computer science and statistics disciplines were more associated with the investigated theses. When the study results were evaluated as a whole, it was seen that significant progress was made in the discipline of management information systems compared to the early 2000s.

  3. Comprehensive Investigation on Current Imbalance among Parallel Chips inside MW-Scale IGBT Power Modules

    DEFF Research Database (Denmark)

    Wu, Rui; Smirnova, Liudmila; Wang, Huai

    2015-01-01

    With the demands for increasing the power rating and improving reliability level of the high power IGBT modules, there are further needs of understanding how to achieve stable paralleling and identical current sharing between the chips. This paper investigates the stray parameters imbalance among...... parallel chips inside the 1.7 kV/1 kA high power IGBT modules at different frequencies by Ansys Q3D parastics extractor. The resulted current imbalance is further confirmed by experimental measurement....

  4. THEORETICAL INVESTIGATION ON BY-ONLY-CURRENT ELECTROMAGNETIC SEPARATION OF INCLUSION FROM MOLTEN METALS

    Institute of Scientific and Technical Information of China (English)

    B.W. Zhang; Z.M. Ren; Y.B. Zhong; K. Deng; K.D. Xu

    2002-01-01

    The electromagnetic field under applied AC and DC current in round and rectangularpipe was systematically investigated, then a concept of "equivalent current density"was proposed for evaluating the inhomogeneous electromagnetic pinch force, and themono-component removal efficiency and the overall removal efficiency of inclusionwere formulated. It is founded that flat pipe is superior to round pipe for the electro-magnetic removal of inclusion, and DC current can get a higher removal efficiencythan AC current due to absence of skin phenomenon. Under usual condition, a re-moval efficiency of 52% for 10μm inclusion or more than 92% for 20μm inclusioncan be achieved by imposing a current density of 3× 106A/m2 in a fiat pipe.

  5. Investigation of pulsed eddy current probes for detection of defects in riveted structures

    Science.gov (United States)

    Yang, Binfeng; Zhang, Hui; Kang, Zhibin; Wang, Xiaofeng

    2013-09-01

    The fatigue crack is the threat to integrity and safety of fuselage lap-joints. Quantification of fatigue cracks by designing and utilisation of an optimised electromagnetic nondestructive evaluation probe can insure the flight safety of aircrafts. In this paper, pulsed eddy current (PEC) for detection and characterisation of fatigue cracks is investigated. The principle of PEC is analysed first, from which four different models of PEC probes are simulated in ANSYS. The signal features, namely zero-crossing time, zero-crossing frequency and peak value are extracted from the time and frequency domains in an effort to qualitatively compare the crack detectability of the four models. The sensitivities of the different probes to cracks are analysed quantitatively. The difference in detectability among the probes is investigated based on the working principle. Simulation results show that the probe consisting of two horizontal detecting coils along with a magnetic field shield focusing the flux has the highest detectability. The conclusions derived from the simulation study are also validated by experiments.

  6. Investigation of Characteristics of Large dB/dt for Geomagnetically Induced Currents

    Science.gov (United States)

    Munoz, D.; Ngwira, C.; Damas, M. C.

    2016-12-01

    When geomagnetically induced currents (GICs) flow through electrical networks, they become a potential threat for electrical power systems. Changes in the geomagnetic field (dB/dt) during severe geomagnetic disturbances are the main sources of GICs. These dB/dt phenomena were studied by selecting 24 strong geomagnetic storms with Dst ≤ - 150 nT. ACE spacecraft solar wind data: flow speed, proton density, By and Bz IMF components of the solar wind were correlated with measurements of the magnetic field detected on ground stations at different latitudes. This article reports characteristics of the solar wind during time intervals of large changes in the horizontal geomagnetic field with a threshold of dB/dt ≥ ± 20 nT/min for the 24 geomagnetic storms. The results of this investigation can help scientists to understand the mechanisms responsible for causing large magnetic field variations in order to predict and mitigate possible large events in the future, which is critical for our society that relies constantly on electricity for livelihood and security. In addition, this ongoing project will continue to investigate electron flux response before, during, and after large changes in geomagnetic field.

  7. Investigation of current status in Europe and USA on boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-11-01

    This report describes on the spot investigation results of current status of medical irradiation in Europe and USA at Feb. 1999. In HFR (Netherlands), the phase 1 study with the Joint Research Centre (JRC) of the EU had been already finished in those days, at the same time, an improvement of medical irradiation field of VTT(Finland) had been finishing and then clinical trial research had been about to start. On the other hand, phase 1 studies by two groups of BNL (Brook heaven National Laboratory) and MIT (Nuclear Engineering of Massachusetts Institute of Technology) in US were now in almost final stage, and they would start on phase 2 study. Either reactors of MIT and BNL were in modification to increase neutron flux, especially that employing fission converter into the irradiation facility and installation of irradiation room were carrying out in the former. In Europe and USA, the accelerator-based BNCT planes are now in progress vigorously, and will have reality. A reform of dynamitron accelerator at University of Birmingham was progressed, and the clinical treatment would be started from September 2000. The accelerator group at MIT has a small type of tandem accelerator, and they were performing basic experiment for BNCS (Boron Neutron Capture Synovectomy) with this accelerator. The concept design for an accelerator and a moderator had been finished at Lawrence Berkeley National Laboratory and University of Berkeley. (author)

  8. Investigation and study on current situation and influencing factors of core midwifery competency in Beijing%北京市助产士核心胜任力现状及影响因素的调查研究

    Institute of Scientific and Technical Information of China (English)

    张贤; 陆虹

    2013-01-01

    目的:了解北京市助产士的核心胜任力现状,并分析其影响因素.方法:采用助产士核心胜任力量表对北京市24家二级以上医院的283名助产士进行横断面调查.结果:助产士核心胜任力总均分为4.02 ±0.47.其中分娩期保健能力、孕期保健能力和产后保健能力3个方面能力较好,而孕前保健能力、公共卫生保健能力和新生儿保健能力三个方面相对薄弱.多元回归分析发现,助产工作年限、职务、编制是助产士核心胜任力的影响因素(P<0.05).结论:北京市助产士核心胜任力水平总体较好,但仍有进一步提升的空间,以满足孕产妇及家属日益增长的服务需求,以及助产士工作范畴拓展和助产专业发展的需要.管理者应根据医院自身情况,对不同特征的助产士实施针对性的培训和管理策略,提高助产士的核心胜任力水平.%Objective: To understand the current situation of core midwifery competency in Beijing, and analyze the influencing factors. Methods: A cross - sectional survey was conducted among 283 midwives from 24 hospitals in Beijing was conducted by Midwife Core Competency Scale. Results: The total score of core midwifery competency was (4. 02 ± 0. 47) on average. The competencies of intrap-artum care, antenatal care, and postpartum care were good, while the competencies of progestational care, public health care, and neonatal health care were weak. Multivariate regression analysis showed that the time of midwifery practice, position, and employment category were influencing factors of core midwifery competency ( P < 0. 05 ) . Conclusion: The overall midwifery competency among Beijing midwives are good, but there are still some areas need to be further improved, so as to satisfy the growing health care demand from pregnant women and their families, as well as the development of the midwifery profession. Managers should develop individualized and specific training and regulation

  9. Investigation of the Critical Current Density of YBaCuO high-temperature Superconductor Ceramic

    OpenAIRE

    METSKHVARISHVILI, I. R.; KEKELIDZE, N. P.; METSKHVARISHVILI, M. R.

    2002-01-01

    The method of high harmonics is used to investigate penetration of low magnetic fields within the Y1Ba2Cu3O7 high-temperature superconductor ceramic. Given experimental results are explained by the modal dependencies between the value of critical current density and the magnetic induction B: jc(B) = jc(0){\\frac{{B02}} {{B02 + B2}}}.

  10. What's Yours Is Mine: An Investigation of Current Copyright Policies of Education Journals

    Science.gov (United States)

    Meyer, Katrina A.

    2009-01-01

    This research investigated the current copyright policies of 21 education journals published by academic societies, universities and university presses, and commercial publishers. For the sample I chose only journals with a copyright policy on the journal or publisher web site, and I then analyzed the content of the policies in order to answer…

  11. Investigation of Leakage Current Waveforms Recorded in a Coastal High Voltage Substation

    Directory of Open Access Journals (Sweden)

    E. Thalassinakis

    2011-06-01

    Full Text Available Leakage current monitoring is a widely employed technique to monitor the performance of outdoor insulation. The evaluation of leakage current waveforms recorded in the field, offers significant information since insulation’s performance is strongly linked with local conditions, and the waveforms’ shape correlate to different types of surface activity. In this paper, an investigation of leakage current waveforms recorded in a 150 kV coastal Substations suffering which suffers intense marine pollution is presented. Investigation of the recorded waveforms verified the basic waveform shapes described in the literature. Further, several variations of the basic types and complex waveforms, as well as field related waveforms, are presented. The need for added categorization criteria in the case of field measurements is discussed.

  12. 新疆高师院校自然科学学报发展现状调查研究%The Investigation and Study on Current Situation of Natural Science Journal in Normal Colleges and University of Xinjiang

    Institute of Scientific and Technical Information of China (English)

    张建国

    2015-01-01

    通过对新疆三所高师院校自然科学版学报载文篇数、作者年龄分布、职称分布、学历分布、刊发文章基金项目情况、内外稿比例等情况调查分析,发现三家学报载文符合科技期刊的载文标准,载文长度呈增长趋势;内稿占多数;三所高校学报的项目成果论文都比较多,并且有逐年增多的趋势;载文作者相对年轻,有相当数量的在读研究生和初级职称作者,中青年中级和副高职称作者是各家学报的主力军。针对发现的问题,高校学报应下大力气建设高水平稳定的作者群,积极应对学术不端行为,加强学报编辑部建设,进一步提高高校学报的办刊质量。%Through the investigation on natural science papers number, distribution of authors’ title, age, ed⁃ucation background , fund program of published articles and the proportion of papers in both inside and outside in the Journal of Xinjiang three normal universities, we have found the papers conform to standards of scientific jour⁃nals, the papers show a tendency to increase in length; most of them are majority; the papers of project achieve⁃ment are more and more, and has the trend of increasing year by year;the authors with papers are relatively young, some of whom are graduate students and junior title. Middle-aged and high title authors are the main force in the journal. According to some problems, journals of colleges and universities should make great efforts to build a high level stable author groups, coping behavior of academic misconduct positively, strengthening construction of the ed⁃itorial office, further improving the quality of the publication of journals of colleges and universities.

  13. Current Research on Chinese Students Studying Abroad

    Science.gov (United States)

    Henze, Jurgen; Zhu, Jiani

    2012-01-01

    As a result of China's growing participation and importance in the process of internationalization and globalization a continuously rising number of Chinese students has gone abroad for further study. By the end of the last decade the number of Chinese students abroad made up the largest group of international students in the USA (surpassing those…

  14. Current Research on Chinese Students Studying Abroad

    Science.gov (United States)

    Henze, Jurgen; Zhu, Jiani

    2012-01-01

    As a result of China's growing participation and importance in the process of internationalization and globalization a continuously rising number of Chinese students has gone abroad for further study. By the end of the last decade the number of Chinese students abroad made up the largest group of international students in the USA (surpassing those…

  15. 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.

  16. An analytical investigation on singularity of current distribution around a crack in a long cylindrical superconductor

    Science.gov (United States)

    Xue, Feng; Zhou, You-He

    2010-06-01

    This paper presents an analytical investigation to display the distribution of critical current flow and trapped magnetic field around a through crack centrally located in a long cylindrical superconductor on the basis of the Bean model and the Kim model. After a simple conformal mapping is employed to the case of that the superconductor is fully penetrated, the current streamlines, the current density, and the trapped field around the crack in the superconductor without deformation are obtained. It is shown that the crack results in a long-range disturbance of J(r ) on the scale much larger than the crack length 2a and a large stagnation region of magnetic flux near the crack except for the singularity of the critical current at the crack tip. Meanwhile, it is also found that the singularity feature is different from the conventional stress one at the crack tip in a deformable body.

  17. Current studies on myofascial pain syndrome.

    Science.gov (United States)

    Kuan, Ta-Shen

    2009-10-01

    Recent studies have clarified the nature of myofascial trigger points (MTrPs). In an MTrP region, multiple hyperirritable loci can be found. The sensory components of the MTrP locus are sensitized nociceptors that are responsible for pain, referred pain, and local twitch responses. The motor components are dysfunctional endplates that are responsible for taut band formation as a result of excessive acetylcholine (ACh) leakage. The concentrations of pain- and inflammation-related substances are increased in the MTrP region. It has been hypothesized that excessive ACh release, sarcomere shortening, and release of sensitizing substances are three essential features that relate to one another in a positive feedback cycle. This MTrP circuit is the connection among spinal sensory (dorsal horn) neurons responsible for the MTrP phenomena. Recent studies suggest that measurement of biochemicals associated with pain and inflammation in the MTrP region, the sonographic study of MTrPs, and the magnetic resonance elastography for taut band image are potential tools for the diagnosis of MTrPs. Many methods have been used to treat myofascial pain, including laser therapy, shockwave therapy, and botulinum toxin type A injection.

  18. Investigating the feasibility of using transcranial direct current stimulation to enhance fluency in people who stutter.

    Science.gov (United States)

    Chesters, Jennifer; Watkins, Kate E; Möttönen, Riikka

    2017-01-01

    Developmental stuttering is a disorder of speech fluency affecting 1% of the adult population. Long-term reductions in stuttering are difficult for adults to achieve with behavioural therapies. We investigated whether a single session of transcranial direct current stimulation (TDCS) could improve fluency in people who stutter (PWS). In separate sessions, either anodal TDCS (1mA for 20min) or sham stimulation was applied over the left inferior frontal cortex while PWS read sentences aloud. Fluency was induced during the stimulation period by using choral speech, that is, participants read in unison with another speaker. Stuttering frequency during sentence reading, paragraph reading and conversation was measured at baseline and at two outcome time points: immediately after the stimulation period and 1h later. Stuttering was reduced significantly at both outcome time points for the sentence-reading task, presumably due to practice, but not during the paragraph reading or conversation tasks. None of the outcome measures were significantly modulated by anodal TDCS. Although the results of this single-session study showed no significant TDCS-induced improvements in fluency, there were some indications that further research is warranted. We discuss factors that we believe may have obscured the expected positive effects of TDCS on fluency, such as heterogeneity in stuttering severity for the sample and variations across sessions. Consideration of such factors may inform future studies aimed at determining the potential of TDCS in the treatment of developmental stuttering. Copyright © 2016. Published by Elsevier Inc.

  19. Tobin Tax: Arguments and Current Derivative Studies

    Directory of Open Access Journals (Sweden)

    Ozekicioglu Seda

    2015-04-01

    Full Text Available Tobin Tax and its derivative applications have started to be discussed again in many platforms as the issue regarding taxation of short-term capital movements has become an agenda among international communities such as European Union (EU and G20 since the beginning of 2000s. In this study, Tobin Tax, which is the first significant step towards taxation of foreign currency transactions, has been discussed theoretically and considering its possible effects on application. Also, in this context, the initiatives of countries such as USA, Belgium, France and Austria regarding international implementation of Tobin Tax and its derivatives are being evaluated. The intended use of the taxes, determination of transactions exempt from tax and international cooperation in the implementation of taxation are possible problems that can be faced regarding Tobin Tax. In this study the conclusion, which the effects of Tobin Tax in developing and developed countries will be different but imposing such tax regarding cyclic balance of the world economy will be a positive improvement, has been reached.

  20. Ocular biomechanics study: current state and perspectives

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2015-03-01

    Full Text Available Despite the fact that the eye represents a challenge for biomechanical research due to its size, over the last two decades, much data on ocular biomechanics were accumulated. Scleral and lamina cribrosa biomechanics contribute to our understanding of myopia and open-angle glaucoma; iris and trabecular meshwork biomechanics to that of angle-closure glaucoma; vitreous biomechanics to that of retinal detachment and ocular drug delivery; corneal biomechanics to that of keratoconus; and lens capsule biomechanics to that of cataract. This paper offers a general overview of recent advances in corneal, scleral, crystalline lens, and lamina cribrosa biomechanics and summarizes the results of experimental and clinical studies. Ocular biomechanics abnormalities affect etiology of many eye diseases. Ocular biomechanics plays an important role in the development of novel diagnostic methods, therapeutic and surgical procedures. Corneal biomechanics impacts etiology and pathogenesis of keratoconus as well as tonometry accuracy and explains corneal refractive surgery effect. Scleral biomechanics is associated with IOP and progressive myopia. Accommodative apparatus (ciliary body and crystalline lens is an important anatomic physiological structure. Recent studies uncovered the causes of agerelated loss of accommodation as a result of lens involution. Optic nerve head abnormalities due to IOP fluctuations are the key factor of glaucomatous neuropathy. They are directly associated with ocular biomechanics as well.

  1. Ocular biomechanics study: current state and perspectives

    Directory of Open Access Journals (Sweden)

    S. Yu. Petrov

    2015-01-01

    Full Text Available Despite the fact that the eye represents a challenge for biomechanical research due to its size, over the last two decades, much data on ocular biomechanics were accumulated. Scleral and lamina cribrosa biomechanics contribute to our understanding of myopia and open-angle glaucoma; iris and trabecular meshwork biomechanics to that of angle-closure glaucoma; vitreous biomechanics to that of retinal detachment and ocular drug delivery; corneal biomechanics to that of keratoconus; and lens capsule biomechanics to that of cataract. This paper offers a general overview of recent advances in corneal, scleral, crystalline lens, and lamina cribrosa biomechanics and summarizes the results of experimental and clinical studies. Ocular biomechanics abnormalities affect etiology of many eye diseases. Ocular biomechanics plays an important role in the development of novel diagnostic methods, therapeutic and surgical procedures. Corneal biomechanics impacts etiology and pathogenesis of keratoconus as well as tonometry accuracy and explains corneal refractive surgery effect. Scleral biomechanics is associated with IOP and progressive myopia. Accommodative apparatus (ciliary body and crystalline lens is an important anatomic physiological structure. Recent studies uncovered the causes of agerelated loss of accommodation as a result of lens involution. Optic nerve head abnormalities due to IOP fluctuations are the key factor of glaucomatous neuropathy. They are directly associated with ocular biomechanics as well.

  2. Investigation of In Vitro Bone Cell Adhesion and Proliferation on Ti Using Direct Current Stimulation.

    Science.gov (United States)

    Bodhak, Subhadip; Bose, Susmita; Kinsel, William C; Bandyopadhyay, Amit

    2012-12-01

    Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 µA, were used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell-materials interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 µA direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 µA electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell-materials interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model.

  3. Study of high current commutation by explosive switch

    Science.gov (United States)

    Usuba, S.; Kakudate, Y.; Yoshida, M.; Fujiwara, S.; Miyamoto, M.; Morita, T.; Kubota, A.; den, M.

    1993-01-01

    The study presents the basic experimental data obtained with a large current opening switch for current commutation using explosives. It is shown that currents up to a maximum of 40 kA can be completely interrupted within 30 microsec. The mechanism of current interruption using a thin conductor plate and methods of measuring interrupting current with a pickup coil and taking photographs with a high-speed camera (one frame per microsec) are discussed.

  4. Investigations of Tracking Phenomena in Silicone Rubber Using Moving Average Current Technique

    Institute of Scientific and Technical Information of China (English)

    R. Sarathi; S. Chandrasekar

    2004-01-01

    In the present work, tracking phenomenon in Silicone rubber material has been studied under AC and DC voltage, with ammonium chloride as a contaminant. It is observed that the tracking is more severe under the DC voltages. The tracking time is less under negative DC compared to the positive DC voltage. The tracking mechanism is explained in detail. The leakage current during the tracking studies was as measured and the moving average technique was adopted to understand the trend in current flow. The leakage current magnitude is high with thermally aged specimens compared to the virgin specimen, irrespective of the type of applied voltage. It is realized that the tracking time and the leakage current magnitude shows an inverse relationship.

  5. Radiological investigation of phosphate fertilizers: Leaching studies.

    Science.gov (United States)

    Hegedűs, Miklós; Tóth-Bodrogi, Edit; Németh, Szabolcs; Somlai, János; Kovács, Tibor

    2017-07-01

    The raw materials of the phosphate fertilizer industry are the various apatite minerals. Some of these have high levels of natural radionuclides, and thus phosphate fertilizers contain significant amounts of U-238, K-40 and Ra-226. These can leach out of the fertilizers used in large quantities for resupplying essential nutrients in the soil and can then enter the food chain through plants, thereby increasing the internal dose of the affected population. In the current study, the radiological risk of eight commercially available phosphate fertilizers (superphosphate, NPK, PK) and their leaching behaviours were investigated using different techniques (gamma and alpha spectrometry), and the dose contributions of using these fertilizers were estimated. To characterize the leaching behaviour, two leaching procedures were applied and compared -the MSZ 21470-50 (Hungarian standard) and the Tessier five-step sequential extraction method. Based on the evaluation of the gamma-spectra, it is found that the level of Th-232 in the samples was low (max.7 ± 6 Bq kg(-1)), the average Ra-226 activity concentration was 309 ± 39 Bq kg(-1) (min. 10 ± 8 Bq kg(-1), max. 570 ± 46 Bq kg(-1)), while the K-40 concentrations (average 3139 ± 188 Bq kg(-1), min. 51 ± 36 Bq kg(-1)) could be as high as 7057 ± 427 Bq kg(-1). The high K-40 can be explained by reference to the composition of the investigated fertilizers (NPK, PK). U concentrations were between 15 and 361 Bq kg(-1), with the average of 254 Bq kg(-1), measured using alpha spectrometry. The good correlation between P2O5 content and radioactivity reported previously is not found in our data. The leaching studies reveal that the mobility of the fertilizer's uranium content is greatly influenced by the parameters of the leaching methods. The availability of U to water ranged between 3 and 28 m/m%, while the Lakanen-Erviö solution mobilized between 10 and 100% of the U content. Copyright © 2016

  6. Experimental Study on Current-Driven Domain Wall Motion

    Science.gov (United States)

    Ono, T.; Yamaguchi, A.; Tanigawa, H.; Yano, K.; Kasai, S.

    2006-06-01

    Current-driven domain wall (DW) motion for a well-defined single DW in a micro-fabricated magnetic wire with submicron width was investigated by real-space observation with magnetic force microscopy. Magnetic force microscopy visualizes that a single DW introduced in a wire is displaced back and forth by positive and negative pulsed-current, respectively. Effect of the Joule heating, reduction of the threshold current density by shape control, and magnetic ratchet effect are also presented.

  7. Principle and experimental investigation of current-driven negative-inductance superconducting quantum interference device

    Science.gov (United States)

    Li, Hao; Liu, Jianshe; Zhang, Yingshan; Cai, Han; Li, Gang; Liu, Qichun; Han, Siyuan; Chen, Wei

    2017-03-01

    A negative-inductance superconducting quantum interference device (nSQUID) is an adiabatic superconducting logic device with high energy efficiency, and therefore a promising building block for large-scale low-power superconducting computing. However, the principle of the nSQUID is not that straightforward and an nSQUID driven by voltage is vulnerable to common mode noise. We investigate a single nSQUID driven by current instead of voltage, and clarify the principle of the adiabatic transition of the current-driven nSQUID between different states. The basic logic operations of the current-driven nSQUID with proper parameters are simulated by WRspice. The corresponding circuit is fabricated with a 100 A cm‑2 Nb-based lift-off process, and the experimental results at low temperature confirm the basic logic operations as a gated buffer.

  8. The Investigation of Primary School Teachers' Opinions Related to the Current Events

    Directory of Open Access Journals (Sweden)

    Halil İbrahim Sağlam

    2016-09-01

    Full Text Available The aim of this study is to examine primary school teachers’ opinions related to current events. The study group is consisted of total 30 primary school teachers who take part in THE GROUPS OF 15 female (%50 and 15 male (%50 in Sakarya during 2015 -2016 the education year. The study is carried out under science facts pattern of qualitative research designs. In order to reveal teachers’ views on current events, the form of semi-structured interviews from which is qualitative data collection tools is used. There are two sections in this study. First section is about teachers' personal information and second section is about teachers' questions to determine their views on current events. For the content validity of the questions in the negotiation form, it has been consulted with three experts and made the necessary adjustments in line with their proposals. In addition, the clarity of the questions in the negotiation form has been checked by discussing with five teachers and then the form has been finalized. The data obtained from teachers ARE analyzed by using content analysis. In the study, it is concluded that 97% of the teachers follow the current events. It is shown that 93% of female teachers and 100% male teachers follow the current events. FURTHERMORE, it is indicated that %100 of the teachers use the internet in their house.

  9. Current Conceptual Challenges in the Study of Rhythm Processing Deficits

    Directory of Open Access Journals (Sweden)

    Pauline eTranchant

    2015-06-01

    Full Text Available Interest in the study of rhythm processing deficits (RPD is currently growing in the cognitive neuroscience community, as this type of investigation constitutes a powerful tool for the understanding of normal rhythm processing. Because this field is in its infancy, it still lacks a common conceptual vocabulary to facilitate effective communication between different researchers and research groups. In this commentary, we provide a brief review of recent reports of RPD through the lens of one important empirical issue: the method by which beat perception is measured, and the consequences of method selection for the researcher’s ability to specify which mechanisms are impaired in RPD. This critical reading advocates for the importance of matching measurement tools to the putative neurocognitive mechanisms under study, and reveals the need for effective and specific assessments of the different aspects of rhythm perception and synchronization.

  10. Anodic Oxidation of Carbon Steel at High Current Densities and Investigation of Its Corrosion Behavior

    Science.gov (United States)

    Fattah-Alhosseini, Arash; Khan, Hamid Yazdani

    2017-02-01

    This work aims at studying the influence of high current densities on the anodization of carbon steel. Anodic protective coatings were prepared on carbon steel at current densities of 100, 125, and 150 A/dm2 followed by a final heat treatment. Coatings microstructures and morphologies were analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM). The corrosion resistance of the uncoated carbon steel substrate and the anodic coatings were evaluated in 3.5 wt pct NaCl solution through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. The results showed that the anodic oxide coatings which were prepared at higher current densities had thicker coatings as a result of a higher anodic forming voltage. Therefore, the anodized coatings showed better anti-corrosion properties compared to those obtained at lower current densities and the base metal.

  11. Study on electrical current variations in electromembrane extraction process: Relation between extraction recovery and magnitude of electrical current.

    Science.gov (United States)

    Rahmani, Turaj; Rahimi, Atyeh; Nojavan, Saeed

    2016-01-15

    This contribution presents an experimental approach to improve analytical performance of electromembrane extraction (EME) procedure, which is based on the scrutiny of current pattern under different extraction conditions such as using different organic solvents as supported liquid membrane, electrical potentials, pH values of donor and acceptor phases, variable extraction times, temperatures, stirring rates, different hollow fiber lengths and the addition of salts or organic solvents to the sample matrix. In this study, four basic drugs with different polarities were extracted under different conditions with the corresponding electrical current patterns compared against extraction recoveries. The extraction process was demonstrated in terms of EME-HPLC analyses of selected basic drugs. Comparing the obtained extraction recoveries with the electrical current patterns, most cases exhibited minimum recovery and repeatability at the highest investigated magnitude of electrical current. . It was further found that identical current patterns are associated with repeated extraction efficiencies. In other words, the pattern should be repeated for a successful extraction. The results showed completely different electrical currents under different extraction conditions, so that all variable parameters have contributions into the electrical current pattern. Finally, the current patterns of extractions from wastewater, plasma and urine samples were demonstrated. The results indicated an increase in the electrical current when extracting from complex matrices; this was seen to decrease the extraction efficiency.

  12. The impact on CT dose of the variability in tube current modulation technology: a theoretical investigation

    Science.gov (United States)

    Li, Xiang; Segars, W. Paul; Samei, Ehsan

    2014-08-01

    Body CT scans are routinely performed using tube-current-modulation (TCM) technology. There is notable variability across CT manufacturers in terms of how TCM technology is implemented. Some manufacturers aim to provide uniform image noise across body regions and patient sizes, whereas others aim to provide lower noise for smaller patients. The purpose of this study was to conduct a theoretical investigation to understand how manufacturer-dependent TCM scheme affects organ dose, and to develop a generic approach for assessing organ dose across TCM schemes. The adult reference female extended cardiac-torso (XCAT) phantom was used for this study. A ray-tracing method was developed to calculate the attenuation of the phantom for a given projection angle based on phantom anatomy, CT system geometry, x-ray energy spectrum, and bowtie filter filtration. The tube current (mA) for a given projection angle was then calculated as a log-linear function of the attenuation along that projection. The slope of this function, termed modulation control strength, α, was varied from 0 to 1 to emulate the variability in TCM technology. Using a validated Monte Carlo program, organ dose was simulated for five α values (α = 0, 0.25, 0.5, 0.75, and 1) in the absence and presence of a realistic system mA limit. Organ dose was further normalized by volume-weighted CT dose index (CTDIvol) to obtain conversion factors (h factors) that are relatively independent of system specifics and scan parameters. For both chest and abdomen-pelvis scans and for 24 radiosensitive organs, organ dose conversion factors varied with α, following second-order polynomial equations. This result suggested the need for α-specific organ dose conversion factors (i.e., conversion factors specific to the modulation scheme used). On the other hand, across the full range of α values, organ dose in a TCM scan could be derived from the conversion factors established for a fixed-mA scan (hFIXED). This was possible by

  13. Investigations on bipolar radio-frequency current application for interstitial thermotherapy (RF-ITT)

    Science.gov (United States)

    Desinger, Kai; Mueller, Gerhard J.; Stein, Thomas; Tschepe, Johannes

    1996-01-01

    This paper discusses the feasibility of radio-frequency current in bipolar technique for interstitial thermotherapy (rf-ITT). A short survey of established methods for interstitial tissue coagulation, e.g. the interstitial laser photocoagulation (ILP) and microwave exposure are given. In addition, a new concept for interstitial application of bipolar or quasi-bipolar radio- frequency alternating current is presented. Theoretical investigations of the electrical field distribution generated by a dipole model come together in the different mechanisms of heat generation by using radio-frequency alternating current. New concepts of bipolar or quasi- bipolar coaxial layered applicators are presented. This bipolar needle electrode enables the surgeon to use a partial and homogeneous exposure of radio-frequency current for interstitial thermotherapy, e.g. for the treatment of BPH or for concha coagulation in ENT. Less power is needed due to the limited current exposition at the immediate operation site and a highly safe procedure is possible. Therefore, to determine the thermal damage of tissue, depending on the rf parameters, a computer model for a real-time simulation of the spatial electrical field distribution especially for a multiple probe application is currently being developed. This is an appropriate tool for dosimetry. A similar program for LITT, called LITCIT, developed at the Laser-Medizin-Zentrum Berlin has already shown its efficiency in clinical use. Furthermore the feasibility of a 'cross-over' applicator is discussed which combines ILP and rf-application by using metallized optical fibers for a simultaneous application of electrical energy and laser radiation.

  14. Experimental Investigations on PV Powered SVM-DTC Induction Motor without AC Phase Current Sensors

    Directory of Open Access Journals (Sweden)

    T. Muthamizhan

    2014-05-01

    Full Text Available The paper presents a low-cost, phase-current reconstruction algorithm for space vector modulated direct torque controlled induction motor using the information obtained from only one shunt resistor which is in series with low side switches in a conventional three-phase inverter. The aim is to develop a low-cost high - performance induction motor drive. It uses the dc-link voltage and dc current to reconstruct the stator currents needed to estimate the motor flux and the electromagnetic torque. Photovoltaic arrays convert solar power to dc electric power; uses chopper and dc-ac inverter to fed three phase Induction Motor. The chopper used here is current fed full bridge boost dc-dc converter, which is preferred and extensively used in high voltage applications and advantageous over voltage fed converters. The inverter switches are controlled by PWM techniques obtained from SVM-DTC of IM. The experimental investigations are given to prove the ability of the proposed scheme of reproducing the performances of a SVM- DTC IM drive.

  15. Investigation of helium ion production in constricted direct current plasma ion source with layered-glows

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yuna [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Chung, Kyoung-Jae, E-mail: jkjlsh1@snu.ac.kr [Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Park, Yeong-Shin [Samsumg Electronics Co. Ltd., Gyeonggi 445-701 (Korea, Republic of); Hwang, Y. S. [Department of Nuclear Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of); Center for Advance Research in Fusion Reactor Engineering, Seoul National University, Seoul 151-744 (Korea, Republic of)

    2014-02-15

    Generation of helium ions is experimentally investigated with a constricted direct current (DC) plasma ion source operated at layered-glow mode, in which electrons could be accelerated through multiple potential structures so as to generate helium ions including He{sup 2+} by successive ionization collisions in front of an extraction aperture. The helium discharge is sustained with the formation of a couple of stable layers and the plasma ball with high density is created near the extraction aperture at the operational pressure down to 0.6 Torr with concave cathodes. The ion beam current extracted with an extraction voltage of 5 kV is observed to be proportional to the discharge current and inversely proportional to the operating pressure, showing high current density of 130 mA/cm{sup 2} and power density of 0.52 mA/cm{sup 2}/W. He{sup 2+} ions, which were predicted to be able to exist due to multiple-layer potential structure, are not observed. Simple calculation on production of He{sup 2+} ions inside the plasma ball reveals that reduced operating pressure and increased cathode area will help to generate He{sup 2+} ions with the layered-glow DC discharge.

  16. Numerical Study on the Bifurcation of the North Equatorial Current

    Institute of Scientific and Technical Information of China (English)

    LIU Yulong; WANG Qi; SONG Jun; ZHU Xiande; GONG Xiaoqing; WU Fang

    2011-01-01

    A 1.5-layer reduced-gravity model forced by wind stress is used to study the bifurcations of the North Equatorial Current (NEC).The authors found that after removing the Ekman drift,the modelled circulations can serve well as a proxy of the SODA circulations on the σθ=25.0kgm-3 potential density surface based on available long-term reanalysis wind stress data.The modelled results show that the location of the western boundary bifurcation of the NEC depends on both zonal averaged and local zero wind stress curl latitude.The effects of the anomalous wind stress curl added in different areas are also investigated and it is found that they can change the strength of the Mindanao Eddy (ME),and then influence the interior pathway.

  17. Investigation of optical currents in coherent and partially coherent vector fields

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Gorsky, M. P.; Maksimyak, P. P.

    2011-01-01

    in the arrangements of two-wave and four-wave superposition on the characteris-tics of the microparticle’s motion has been analyzed. The prospects of stud-ying temporal coherence using the proposed approach are made. For the first time, the possibility of diagnostics of optical currents in liquids caused...

  18. Investigation of assumptions underlying current safety guidelines on EM-induced nerve stimulation

    Science.gov (United States)

    Neufeld, Esra; Vogiatzis Oikonomidis, Ioannis; Iacono, Maria Ida; Angelone, Leonardo M.; Kainz, Wolfgang; Kuster, Niels

    2016-06-01

    An intricate network of a variety of nerves is embedded within the complex anatomy of the human body. Although nerves are shielded from unwanted excitation, they can still be stimulated by external electromagnetic sources that induce strongly non-uniform field distributions. Current exposure safety standards designed to limit unwanted nerve stimulation are based on a series of explicit and implicit assumptions and simplifications. This paper demonstrates the applicability of functionalized anatomical phantoms with integrated coupled electromagnetic and neuronal dynamics solvers for investigating the impact of magnetic resonance exposure on nerve excitation within the full complexity of the human anatomy. The impact of neuronal dynamics models, temperature and local hot-spots, nerve trajectory and potential smoothing, anatomical inhomogeneity, and pulse duration on nerve stimulation was evaluated. As a result, multiple assumptions underlying current safety standards are questioned. It is demonstrated that coupled EM-neuronal dynamics modeling involving realistic anatomies is valuable to establish conservative safety criteria.

  19. Investigation of leakage current and breakdown voltage in irradiated double-sided 3D silicon sensors

    Science.gov (United States)

    Dalla Betta, G.-F.; Ayllon, N.; Boscardin, M.; Hoeferkamp, M.; Mattiazzo, S.; McDuff, H.; Mendicino, R.; Povoli, M.; Seidel, S.; Sultan, D. M. S.; Zorzi, N.

    2016-09-01

    We report on an experimental study aimed at gaining deeper insight into the leakage current and breakdown voltage of irradiated double-sided 3D silicon sensors from FBK, so as to improve both the design and the fabrication technology for use at future hadron colliders such as the High Luminosity LHC. Several 3D diode samples of different technologies and layout are considered, as well as several irradiations with different particle types. While the leakage current follows the expected linear trend with radiation fluence, the breakdown voltage is found to depend on both the bulk damage and the surface damage, and its values can vary significantly with sensor geometry and process details.

  20. Investigation of in vitro bone cell adhesion and proliferation on Ti using direct current stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Bodhak, Subhadip; Bose, Susmita [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States); Kinsel, William C. [Mechanical Engineering, Washington State University, Tri-Cities, WA (United States); Bandyopadhyay, Amit, E-mail: amitband@wsu.edu [W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920 (United States)

    2012-12-01

    Our objective was to establish an in vitro cell culture protocol to improve bone cell attachment and proliferation on Ti substrate using direct current stimulation. For this purpose, a custom made electrical stimulator was developed and a varying range of direct currents, from 5 to 25 {mu}A, was used to study the current stimulation effect on bone cells cultured on conducting Ti samples in vitro. Cell-material interaction was studied for a maximum of 5 days by culturing with human fetal osteoblast cells (hFOB). The direct current was applied in every 8 h time interval and the duration of electrical stimulation was kept constant at 15 min for all cases. In vitro results showed that direct current stimulation significantly favored bone cell attachment and proliferation in comparison to nonstimulated Ti surface. Immunochemistry and confocal microscopy results confirmed that the cell adhesion was most pronounced on 25 {mu}A direct current stimulated Ti surfaces as hFOB cells expressed higher vinculin protein with increasing amount of direct current. Furthermore, MTT assay results established that cells grew 30% higher in number under 25 {mu}A electrical stimulation as compared to nonstimulated Ti surface after 5 days of culture period. In this work we have successfully established a simple and cost effective in vitro protocol offering easy and rapid analysis of bone cell-material interaction which can be used in promotion of bone cell attachment and growth on Ti substrate using direct current electrical stimulation in an in vitro model. - Highlights: Black-Right-Pointing-Pointer D.C. stimulation was used to enhance in vitro bone cell adhesion and proliferation. Black-Right-Pointing-Pointer Cells cultured on Ti were stimulated by using a custom made electrical stimulator. Black-Right-Pointing-Pointer Optimization was performed by using a varying range of direct currents {approx} 5 to 25 {mu}A. Black-Right-Pointing-Pointer 25 {mu}A stimulation was found most beneficial

  1. EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF HIGH CONCENTRATION JETS IN ENVIRONMENTAL CURRENTS

    Institute of Scientific and Technical Information of China (English)

    张燕; 王道增; 樊靖郁

    2002-01-01

    By means of flow visualization and quantitative measurement, the diffusionpattern and concentration distribution characteristics of high concentration jets verticallydischarged into shallow moving waterbody were experimentally investigated in waterchannel. The interactions between the high concentration jets and environmental flowconditions were analysed, and the formulae of impinging point coordinate and transversespread angle are gained from data analysis. Experimental results indicate that the jets showcomplicated flow patterns and diffusion characteristics in near region, which are differentfrom common submerged jets, and spread downstream in the manner of density currents.

  2. An investigation into the lepton flavor changing neutral current at a Z-factory

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The potential for detecting the lepton flavor changing neutral current (LFCNC) via the Z → eτ rare decay at a Z-factory is investigated.Practicable event selection strategies are designed to increase signal significance over SM contributions.Assuming no apparent deviation from SM predictions,one can conclude that the most general model-independent LFCNC effective form factors would be constrained at an unprecedent level,and accordingly a 3-order improvement from LEP1 measurements on the upper limit of BR(Z → eτ) could be achieved,as precisely as 10-8 with 100 fb-1 at Z-factory.

  3. Chosen Aspects Of Investigations Of Solar Cells With The Laser Beam Induced Current Technique

    Directory of Open Access Journals (Sweden)

    Chrobak Łukasz Bartłomiej

    2015-06-01

    Full Text Available This paper presents maps of spatial distributions of the short circuit current Isc(x,y and the open circuit voltage Uoc(x,y of the investigated low cost solar cells. Visible differences in values of these parameters were explained by differences in the serial and shunt resistances determined for different points of solar cells from measurements of I–V characteristics. The spectral dependence of the photo voltage of solar cell is also shown, discussed and interpreted in the model of amorphous and crystal silicon.

  4. Beam brilliance investigation of high current ion beams at GSI heavy ion accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Adonin, A. A., E-mail: a.adonin@gsi.de; Hollinger, R. [Linac and Operations/Ion Sources, GSI Helmholtzzentrum für Schwerionenforschung GmbH, Darmstadt (Germany)

    2014-02-15

    In this work the emittance measurements of high current Ta-beam provided by VARIS (Vacuum Arc Ion Source) ion source are presented. Beam brilliance as a function of beam aperture at various extraction conditions is investigated. Influence of electrostatic ion beam compression in post acceleration gap on the beam quality is discussed. Use of different extraction systems (single aperture, 7 holes, and 13 holes) in order to achieve more peaked beam core is considered. The possible ways to increase the beam brilliance are discussed.

  5. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    2002-01-01

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle orbit

  6. Investigation of sounding rocket observations of field-aligned currents and electron temperature

    Science.gov (United States)

    Cohen, I. J.; Lessard, M.; Zettergren, M. D.; Moen, J.; Lynch, K. A.; Heavisides, J. M.

    2014-12-01

    Strangeway et al. [2005] and other authors have concluded that the establishment of the ambipolar field by the deposition of energy from soft electron precipitation is a significant driver of type-2 ion upflows. Likewise, Clemmons et al. [2008] and Zhang et al. [2012] proposed processes by which soft electron precipitation may play a role in heating neutrals and contribute to neutral upwelling. In both situations the thermal ionospheric electron population plays a crucial role in both generation of the ambipolar field and in collisional energy exchange with the atmosphere through a variety of processes. In this study we examine the dynamics of the electron population, specifically the temperature, in a slightly different context - focusing on the auroral downward current region (DCR). In many cases auroral DCRs may be depleted of plasma, which sets up interesting conditions involving thermoelectric heat fluxes (which flow upward - in the opposite direction from the current), adiabatic expansion due to the high (upward) speed of the electrons carrying the downward current, heat exchange from ions which have elevated temperatures due to frictional heating, and direct frictional heating of the electrons. A detailed understanding of the electron temperature in auroral DCRs is necessary to make quantitative statements about recombination, upflow, cavitation and a host of other processes relevant to ion outflow. In this study, we compare in situ rocket observations of electron temperature, density, and current densities with predictions from the Zettergren and Semeter [2012] model in an attempt to better understand the dynamics and relationships between these parameters in DCRs.

  7. Simulation studies of direct-current microdischarges for electric propulsion

    Science.gov (United States)

    Deconinck, Thomas Dominique

    The structure of direct-current microdischarges is investigated using a detailed two-dimensional multi-species continuum model. Microdischarges are direct-current discharges that operate at a relatively high pressure of about 100 Torr and geometric dimensions in the 10-100 micrometer range. Our motivation for the study of microdischarges comes from a potential application of these devices in microthrusters for small satellite propulsion. The Micro Plasma Thruster (MPT) concept consists of a direct-current microdischarge in a geometry comprising a constant area flow section followed by a diverging exit nozzle. A detailed description of the plasma dynamics inside the MPT including power deposition, ionization, coupling of the plasma phenomena with high-speed flow, and propulsion system performance is reported in this study. A two-dimensional model is developed as part of this study. The model consists of a plasma module coupled to a flow module and is solved on a hybrid unstructured mesh framework. The plasma module provides a self-consistent, multi-species, multi-temperature description of the microdischarge phenomena while the flow module provides a description of the low Reynolds number compressible flow through the system. The plasma module solves conservation equations for plasma species continuity and electron energy, and Poisson's equation for the self-consistent electric field. The flow module solves mass, bulk gas momentum and energy equations. The coupling of energy from the electrostatic field to the plasma species is modeled by the Joule heating term which appears in the electron and heavy species energy equations. Discretization of the Joule heating term on unstructured meshes requires special attention. We propose a new robust method for the numerical discretization of the Joule heating term on such meshes using a cell-centered, finite volume approach. A prototypical microhollow cathode discharge (MHCD) is studied to guide and validate the modeling

  8. The role of high-resolution geomagnetic field models for investigating ionospheric currents at low Earth orbit satellites

    Science.gov (United States)

    Stolle, Claudia; Michaelis, Ingo; Rauberg, Jan

    2016-07-01

    Low Earth orbiting geomagnetic satellite missions, such as the Swarm satellite mission, are the only means to monitor and investigate ionospheric currents on a global scale and to make in situ measurements of F region currents. High-precision geomagnetic satellite missions are also able to detect ionospheric currents during quiet-time geomagnetic conditions that only have few nanotesla amplitudes in the magnetic field. An efficient method to isolate the ionospheric signals from satellite magnetic field measurements has been the use of residuals between the observations and predictions from empirical geomagnetic models for other geomagnetic sources, such as the core and lithospheric field or signals from the quiet-time magnetospheric currents. This study aims at highlighting the importance of high-resolution magnetic field models that are able to predict the lithospheric field and that consider the quiet-time magnetosphere for reliably isolating signatures from ionospheric currents during geomagnetically quiet times. The effects on the detection of ionospheric currents arising from neglecting the lithospheric and magnetospheric sources are discussed on the example of four Swarm orbits during very quiet times. The respective orbits show a broad range of typical scenarios, such as strong and weak ionospheric signal (during day- and nighttime, respectively) superimposed over strong and weak lithospheric signals. If predictions from the lithosphere or magnetosphere are not properly considered, the amplitude of the ionospheric currents, such as the midlatitude Sq currents or the equatorial electrojet (EEJ), is modulated by 10-15 % in the examples shown. An analysis from several orbits above the African sector, where the lithospheric field is significant, showed that the peak value of the signatures of the EEJ is in error by 5 % in average when lithospheric contributions are not considered, which is in the range of uncertainties of present empirical models of the EEJ.

  9. 系外行星大气研究现状%Current Investigations on Exoplanetary Atmospheres

    Institute of Scientific and Technical Information of China (English)

    田蕾; 季江徽

    2015-01-01

    The ultimate goal for detecting exoplanets is to search for extraterrestrial life and habitable terrestrial planets. The exoplanetary atmosphere acts as a good window to understand exoplanet’s characteristics and habitability. Hence, such investigation is one of the most significant frontiers in astronomy. In the last decade, tremendous achievements have been made on the theories of the exoplanetary atmosphere, and observations through photometric and spectroscopic methods using a variety of space-borne and ground-based observational facilities. However, currently the atmosphere observations mainly come from transiting hot Jupiters, super-Earths and direct imaging giant planets, because of limitation in current observational techniques. The present review attempts to succinctly summarize current investigations in this field. First, we briefly describe the methods of observing exoplanetary atmospheres. Next, we review the fundamental facts, nowadays research progress of atmospheres for hot Jupiters and super-Earths. Finally,we present an introduction of the projects, which are involved in exoplanetary atmosphere detection to show the bright prospects for future investigation.%探测系外行星的最终目的是为了寻找系外生命和宜居行星,而系外行星大气是人们了解行星宜居特性的窗口,所以系外行星大气的研究至关重要。近10年来,系外行星大气的理论研究和观测都发展迅速。受观测技术限制,目前观测到大气的系外行星主要是用凌星法探测到的热木星和超级地球,还有用直接成像法探测到的离主星较远的年轻气态巨行星。力求在系外行星大气领域飞速发展之际,对该领域研究现状做简明介绍。首先介绍系外行星大气的观测方法,随后介绍热木星和超级地球的大气概况和研究现状,最后对系外行星大气探测的有关项目进行简要介绍,以展示未来系外行星大气研究的前景。

  10. A computational investigation of cardiac caveolae as a source of persistent sodium current

    Directory of Open Access Journals (Sweden)

    Ian M. Besse

    2011-11-01

    Full Text Available Recent studies of cholesterol-rich membrane microdomains, called caveolae, reveal that caveolae are reservoirs of recruitable sodium ion channels. Caveolar channels constitute a substantial and previously unrecognized source of sodium current in cardiac cells. In this paper we model for the first time caveolar sodium currents and their contributions to cardiac action potential morphology. We show that the beta-agonist-induced opening of caveolae may have substantial impacts on peak overshoot, maximum upstroke velocity, and ultimately conduction velocity. Additionally, we show that prolonged action potentials and the formation of potentially arrhythmogenic afterdepolarizations, can arise if caveolae open intermittently throughout the action potential. Our simulations suggest that there may exist routes to delayed repolarization, and the arrhythmias associated with such delays, that are independent of channelopathies.

  11. Investigation of drain current transient behavior in SLS TFTs with the DLTS technique

    Energy Technology Data Exchange (ETDEWEB)

    Exarchos, M A [National and Kapodistrian University of Athens, Physics Department, Solid State Physics Section, Athens 15784 (Greece); Papaioannou, G J [National and Kapodistrian University of Athens, Physics Department, Solid State Physics Section, Athens 15784 (Greece); Kouvatsos, D N [N.C.S.R. Demokritos, Institute of Microelecronics, Athens 15310 (Greece); Voutsas, A T [L.C.D. Process Technology Laboratory, SHARP Labs of America, Inc., Washington 98607 (United States)

    2005-01-01

    In this work, the study of drain current overshoot transients of thin film transistors (TFTs) fabricated by excimer laser sequential lateral solidification (ELA SLS) process is presented. Drain current transient behavior, is ascribed to carrier capture/emission processes within the transistors' Si body, and represents complex mechanisms differently responding at dark and under illumination conditions. Additionally, the thickness of the Si body film, which is an important parameter for the material structure evaluation, ranged from 30 nm to 100 nm. The results were stemmed by deep level transient spectroscopy (DLTS) technique and measurements were conducted within the temperature interval of 200 K to 400 K. The impact of illumination, contributes mainly at lower temperatures through electron-hole generation processes, compensating though carrier freeze-out phenomena.

  12. Investigation of drain current transient behavior in SLS TFTs with the DLTS technique

    Science.gov (United States)

    Exarchos, M. A.; Papaioannou, G. J.; Kouvatsos, D. N.; Voutsas, A. T.

    2005-01-01

    In this work, the study of drain current overshoot transients of thin film transistors (TFTs) fabricated by excimer laser sequential lateral solidification (ELA SLS) process is presented. Drain current transient behavior, is ascribed to carrier capture/emission processes within the transistors' Si body, and represents complex mechanisms differently responding at dark and under illumination conditions. Additionally, the thickness of the Si body film, which is an important parameter for the material structure evaluation, ranged from 30 nm to 100 nm. The results were stemmed by deep level transient spectroscopy (DLTS) technique and measurements were conducted within the temperature interval of 200 K to 400 K. The impact of illumination, contributes mainly at lower temperatures through electron-hole generation processes, compensating though carrier freeze-out phenomena.

  13. Study of a fibre optics current sensor for the measurement of plasma current in ITER

    Science.gov (United States)

    Wuilpart, Marc; Vanus, Benoit; Andrasan, Alina; Gusarov, Andrei; Moreau, Philippe; Mégret, Patrice

    2016-05-01

    In this article, we study the feasibility of using a fibre-optics current sensor (FOCS) for the measurement of plasma current in the future fusion reactor ITER. The sensor is based on a classical FOCS interrogator involving the measurement of the state of polarization rotation undergone by the light in presence of a magnetic field (Faraday effect) in an optical fibre surrounding the current and terminated by a Faraday mirror. We considered a uniformly spun optical fibre as the sensing element and we used the Stokes formalism to simulate the sensor. The objective of the simulations is to quantify the ratio LB/SP (beat length over the spun period of the spun fibre) enabling a measurement error in agreement with the ITER specifications. The simulator takes into account the temperature variations undergone by the measurement system under ITER operation. The simulation work showed that a LB/SP ratio of 19.2 is adequate.

  14. An investigation of the role of current and future remote sensing data systems in numerical meteorology

    Science.gov (United States)

    Diak, George R.; Smith, William L.

    1993-01-01

    The goals of this research endeavor have been to develop a flexible and relatively complete framework for the investigation of current and future satellite data sources in numerical meteorology. In order to realistically model how satellite information might be used for these purposes, it is necessary that Observing System Simulation Experiments (OSSEs) be as complete as possible. It is therefore desirable that these experiments simulate in entirety the sequence of steps involved in bringing satellite information from the radiance level through product retrieval to a realistic analysis and forecast sequence. In this project we have worked to make this sequence realistic by synthesizing raw satellite data from surrogate atmospheres, deriving satellite products from these data and subsequently producing analyses and forecasts using the retrieved products. The accomplishments made in 1991 are presented. The emphasis was on examining atmospheric soundings and microphysical products which we expect to produce with the launch of the Advanced Microwave Sounding Unit (AMSU), slated for flight in mid 1994.

  15. An Investigation on the Current Situation of Management Information Systems Discipline in Turkey

    OpenAIRE

    Serdar YARLIKAŞ

    2015-01-01

    The purpose of this research is to investigate the development of management information systems field by evaluating the theses conducted at universities in Turkey in the departments of management information systems and science of management information systems. First, this study aims to determine the distribution of the theses in terms of years, subjects and the research methods used. Another purpose of this study was to determine which of the related disciplines of management information s...

  16. Experimental study of the dynamics of a thin current sheet

    Science.gov (United States)

    Gekelman, W.; DeHaas, T.; Van Compernolle, B.; Daughton, W.; Pribyl, P.; Vincena, S.; Hong, D.

    2016-05-01

    Many plasmas in natural settings or in laboratory experiments carry currents. In magnetized plasmas the currents can be narrow field-aligned filaments as small as the electron inertial length ≤ft(\\tfrac{c}{{ω }pe}\\right) in the transverse dimension or fill the entire plasma column. Currents can take the form of sheets, again with the transverse dimension the narrow one. Are laminar sheets of electric current in a magnetized plasma stable? This became an important issue in the 1960s when current-carrying plasmas became key in the quest for thermonuclear fusion. The subject is still under study today. The conditions necessary for the onset for tearing are known, the key issue is that of the final state. Is there a final state? One possibility is a collection of stable tubes of current. On the other hand, is the interaction between the current filaments which are the byproduct endless, or does it go on to become chaotic? The subject of three-dimensional current systems is intriguing, rich in a variety of phenomena on multiple scale sizes and frequencies, and relevant to fusion studies, solar physics, space plasmas and astrophysical phenomena. In this study a long (δz = 11 m) and narrow (δx = 1 cm, δy = 20 cm) current sheet is generated in a background magnetoplasma capable of supporting Alfvén waves. The current is observed to rapidly tear into a series of magnetic islands when viewed in a cross-sectional plane, but they are in essence three-dimensional flux ropes. At the onset of the current, magnetic field line reconnection is observed between the flux ropes. The sheet on the whole is kink-unstable, and after kinking exhibits large-scale, low-frequency (f ≪ f ci ) rotation about the background field with an amplitude that grows with distance from the source of the current. Three-dimensional data of the magnetic and electric fields is acquired throughout the duration of the experiment and the parallel resistivity is derived from it. The parallel

  17. Theoretical study of rock mass investigation efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Holmen, Johan G.; Outters, Nils [Golder Associates, Uppsala (Sweden)

    2002-05-01

    The study concerns a mathematical modelling of a fractured rock mass and its investigations by use of theoretical boreholes and rock surfaces, with the purpose of analysing the efficiency (precision) of such investigations and determine the amount of investigations necessary to obtain reliable estimations of the structural-geological parameters of the studied rock mass. The study is not about estimating suitable sample sizes to be used in site investigations.The purpose of the study is to analyse the amount of information necessary for deriving estimates of the geological parameters studied, within defined confidence intervals and confidence level In other words, how the confidence in models of the rock mass (considering a selected number of parameters) will change with amount of information collected form boreholes and surfaces. The study is limited to a selected number of geometrical structural-geological parameters: Fracture orientation: mean direction and dispersion (Fisher Kappa and SRI). Different measures of fracture density (P10, P21 and P32). Fracture trace-length and strike distributions as seen on horizontal windows. A numerical Discrete Fracture Network (DFN) was used for representation of a fractured rock mass. The DFN-model was primarily based on the properties of an actual fracture network investigated at the Aespoe Hard Rock Laboratory. The rock mass studied (DFN-model) contained three different fracture sets with different orientations and fracture densities. The rock unit studied was statistically homogeneous. The study includes a limited sensitivity analysis of the properties of the DFN-model. The study is a theoretical and computer-based comparison between samples of fracture properties of a theoretical rock unit and the known true properties of the same unit. The samples are derived from numerically generated boreholes and surfaces that intersect the DFN-network. Two different boreholes are analysed; a vertical borehole and a borehole that is

  18. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Science.gov (United States)

    Carvalho, Antonio José Felix; Viana, Vicente Galber Freitas; Faria, Roberto Mendonça

    2009-12-01

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak β), an intermediate peak (peak α), and a third that appeared at a temperature coincident with the polarization temperature (peak ρ). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes.

  19. Thermally stimulated depolarization current studies of sulfonated polystyrene ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Antonio Jose Felix [Universidade Federal de Sao Carlos, Laboratory of Polymers and Renewable Materials, Sorocaba, SP (Brazil); Viana, Vicente Galber Freitas [Universidade Federal do Piaui, Centro de Ciencias da Natureza, Teresina, PI (Brazil); Faria, Roberto Mendonca [USP, Instituto de Fisica de Sao Carlos, SP (Brazil)

    2009-12-15

    A detailed study of thermally stimulated depolarization current (TSDC) was carried out to investigate dipolar relaxation and the charge storage phenomenon in films of sulfonated polystyrene (SPS) ionomers having lithium or potassium as counterions. Differential scanning calorimetry measurements were also applied as a complementary technique, mainly to follow the change of the glass transition temperature with the amount of sulfonated groups. It was observed that, since the glass transition does not change significantly with the amount of sulfonated groups, a cluster of multiplets is expected not to be formed in the range used in this work. TSDC of SPS samples polarized at temperatures higher than the glass transition temperature showed three peaks: one at lower temperature (peak {beta}), an intermediate peak (peak {alpha}), and a third that appeared at a temperature coincident with the polarization temperature (peak {rho}). Quantitative information about trapping-detrapping and dipolar relaxation and their corresponding activation energies was determined by fittings of the deconvoluted peaks with kinetic relaxation processes. (orig.)

  20. A clinical and investigational study of donovanosis

    Directory of Open Access Journals (Sweden)

    Veeranna S

    2003-03-01

    Full Text Available A clinical and investigational study of 25 cases of Donovanosis was undertaken. The incidence was found to be 1.53% of all STD cases and 2.9% of GUD. M:F ratio was 2.12:1. Incidence was more in unmarried people. Fleshy exuberant type was seen in 88% of cases. Two patients (8% had extragenital ulcers. Donovan bodies were found in 88%. Pseudo elephantiasis was seen in 8 patients. Biopsy was done in 8 cases and showed ocanthosis, plasma cell infiltration and pseudo epitheliomatous hyperplasia. One patient developed squamous cell carcinoma of vulva.

  1. Study on Fault Current of DFIG during Slight Fault Condition

    OpenAIRE

    Xiangping Kong; Zhe Zhang; Xianggen Yin; Zhenxing Li

    2013-01-01

    In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influenc...

  2. INVESTIGATING DISTANCE EDUCATION STUDENTS’ STUDY SKILLS

    Directory of Open Access Journals (Sweden)

    Cengiz POYRAZ

    2013-10-01

    Full Text Available Distance education, which is a planned way of teaching in which students and instructors are brought face to face in a classroom environment in several different ways by means of technology, has started to become widespread in many fields today. In distance education, students and instructors reside in different locations. Students can learn at their pace and control their learning path, content and load of what they have learned and evaluate it. However, they should adopt strategies for effective studying in order not to waste their time and efforts. Because study skills, motivation, time management, exam preparation and coping with exam stress have an impact on students’ success. In this context, distance education students’ study skills are foregrounded in today’s widespread use of distance education. In accordance with this, this study aims to investigate some variables which are influential on the dimensions of distance education students’ motivation, time management, exam preparation and coping with exam stress. A personal information form and the Study Skills scale were used for data collection. This study was designed in survey model and SPSS16.0 statistical package program was used for the statistical analyses of the research data. The research findings were discussed in line with the literature and some suggestions were presented for further research and researchers.

  3. Numerical Investigation of Flow Motion and Performance of A Horizontal Axis Tidal Turbine Subjected to A Steady Current

    Institute of Scientific and Technical Information of China (English)

    李林娟; 郑金海; 彭于轩; 张继生; 吴修广

    2015-01-01

    Horizontal axis tidal turbines have attracted more and more attentions nowadays, because of their convenience and low expense in construction and high efficiency in extracting tidal energy. The present study numerically investigates the flow motion and performance of a horizontal axis tidal turbine with a supporting vertical cylinder under steady current. In the numerical model, the continuous equation and incompressible Reynolds-averaged Navier-Stokes equations are solved, and the volume of fluid method is employed to track free surface motion. The RNG k-εmodel is adopted to calculate turbulence transport while the fractional area/volume obstacle representation method is used to describe turbine characteristics and movement. The effects of installation elevation of tidal turbine and inlet velocity on the water elevation, and current velocity, rotating speed and resultant force on turbine are discussed. Based on the comparison of the numerical results, a better understanding of flow structure around horizontal axis tidal turbine and turbine performance is achieved.

  4. Deterministic and Stochastic Study of Wind Farm Harmonic Currents

    DEFF Research Database (Denmark)

    Sainz, Luis; Mesas, Juan Jose; Teodorescu, Remus;

    2010-01-01

    Wind farm harmonic emissions are a well-known power quality problem, but little data based on actual wind farm measurements are available in literature. In this paper, harmonic emissions of an 18 MW wind farm are investigated using extensive measurements, and the deterministic and stochastic...... characterization of wind farm harmonic currents is analyzed. Specific issues addressed in the paper include the harmonic variation with the wind farm operating point and the random characteristics of their magnitude and phase angle....

  5. The mesospheric sodium layer as a remotely, optically pumped magnetometer for investigation of Birkeland currents

    Science.gov (United States)

    Johnsen, Magnar G.; Matzka, Jürgen; Hoppe, Ulf-Peter

    2016-04-01

    By means of optical pumping, it is possible to use the naturally occurring sodium layer in the mesosphere to measure Earth's scalar magnetic field at ~90 km above ground. This is an altitude not accessible by other means than rockets, which only will provide point measurements of very short time scales. We are planning to modify the sodium lidar at ALOMAR in Northern Norway to be able, for the first time, to measure and monitor the magnetic field in situ in the high latitude mesosphere over longer time scales. The planned modifications to the lidar instrument will allow alternating between the new magnetometer mode and its present mode for atmospheric temperatures and winds. The technique, which has been proposed earlier for measurements at low or mid-latitudes for studies of Earth's internal magnetic field, will in our project be applied to high latitudes in the auroral zone. This opens for a completely new domain of measurements of externally generated geomagnetic variations related to currents in the magnetosphere-ionosphere system. In particular, we aim to measure the magnetic field variations in close vicinity to Birkeland currents associated with particle precipitation events penetrating to altitudes below 90 km and small-scale, discrete auroral arcs. It is, furthermore, anticipated that it will be possible to detect horizontal current structures in the E-layer on much smaller length scales than it is presently possible from ground observations alone. During the project we plan take advantage of the rich space science infrastructure located in northern Norway, including ALOMAR, EISCAT and the Tromsø Geophysical Observatory magnetometer network. If possible, we also aim to make measurements in conjunction with overpasses of the SWARM satellites.

  6. Neuroscience Investigations: An Overview of Studies Conducted

    Science.gov (United States)

    Reschke, Millard F.

    1999-01-01

    The neural processes that mediate human spatial orientation and adaptive changes occurring in response to the sensory rearrangement encountered during orbital flight are primarily studied through second and third order responses. In the Extended Duration Orbiter Medical Project (EDOMP) neuroscience investigations, the following were measured: (1) eye movements during acquisition of either static or moving visual targets, (2) postural and locomotor responses provoked by unexpected movement of the support surface, changes in the interaction of visual, proprioceptive, and vestibular information, changes in the major postural muscles via descending pathways, or changes in locomotor pathways, and (3) verbal reports of perceived self-orientation and self-motion which enhance and complement conclusions drawn from the analysis of oculomotor, postural, and locomotor responses. In spaceflight operations, spatial orientation can be defined as situational awareness, where crew member perception of attitude, position, or motion of the spacecraft or other objects in three-dimensional space, including orientation of one's own body, is congruent with actual physical events. Perception of spatial orientation is determined by integrating information from several sensory modalities. This involves higher levels of processing within the central nervous system that control eye movements, locomotion, and stable posture. Spaceflight operational problems occur when responses to the incorrectly perceived spatial orientation are compensatory in nature. Neuroscience investigations were conducted in conjunction with U. S. Space Shuttle flights to evaluate possible changes in the ability of an astronaut to land the Shuttle or effectively perform an emergency post-landing egress following microgravity adaptation during space flights of variable length. While the results of various sensory motor and spatial orientation tests could have an impact on future space flights, our knowledge of

  7. Metabolic Investigation in Gluconacetobacter xylinus and Its Bacterial Cellulose Production under a Direct Current Electric Field.

    Science.gov (United States)

    Liu, Miao; Zhong, Cheng; Zhang, Yu Ming; Xu, Ze Ming; Qiao, Chang Sheng; Jia, Shi Ru

    2016-01-01

    The effects of a direct current (DC) electric field on the growth and metabolism of Gluconacetobacter xylinus were investigated in static culture. When a DC electric field at 10 mA was applied using platinum electrodes to the culture broth, bacterial cellulose (BC) production was promoted in 12 h but was inhibited in the last 12 h as compared to the control (without DC electric field). At the cathode, the presence of the hydrogen generated a strong reductive environment that is beneficial to cell growth. As compared to the control, the activities of glycolysis and tricarboxylic acid cycle, as well as BC productivity were observed to be slightly higher in the first 12 h. However, due to the absence of sufficient oxygen, lactic acid was accumulated from pyruvic acid at 18 h, which was not in favor of BC production. At the anode, DC inhibited cell growth in 6 h when compared to the control. The metabolic activity in G. xylinus was inhibited through the suppression of the tricarboxylic acid cycle and glycolysis. At 18-24 h, cell density was observed to decrease, which might be due to the electrolysis of water that significantly dropped the pH of cultural broth far beyond the optimal range. Meanwhile, metabolites for self-protection were accumulated, for instance proline, glutamic acid, gluconic acid, and fatty acids. Notably, the accumulation of gluconic acid and lactic acid made it a really tough acid stress to cells at the anode and finally led to depression of cell growth.

  8. Investigation of Deep Dielectric Charging and Subsequent Currents on Geosynchronous Spacecraft

    Science.gov (United States)

    1991-12-01

    backscatter+ jh True ambient flux is all of the flux that surrounds the spacecraft. Ambient current density is current/unit area that comes from the ambient...We tacitly assume the currents are constant over the periods of integration. (5) Lnet= nambient +Jenergetic+Jsecondary+ Jbackscatter+ Jhv For the two

  9. Study of the weak charged hadronic current in b decays

    Science.gov (United States)

    Acciarri, M.; Adriani, O.; Aguilar-Benitez, M.; Ahlen, S.; Alpat, B.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alverson, G.; Alviggi, M. G.; Ambrosi, G.; Anderhub, H.; Andreev, V. P.; Angelescu, T.; Anselmo, F.; Antreasyan, D.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Baksay, L.; Ball, R. C.; Banerjee, S.; Banicz, K.; Barillère, R.; Barone, L.; Bartalini, P.; Baschirotto, A.; Basile, M.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Bhattacharya, S.; Biasini, M.; Biland, A.; Bilei, G. M.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Bock, R.; Böhm, A.; Borgia, B.; Boucham, A.; Bourilkov, D.; Bourquin, M.; Boutigny, D.; Branson, J. G.; Brigljevic, V.; Brock, I. C.; Buffini, A.; Buijs, A.; Burger, J. D.; Burger, W. J.; Busenitz, J.; Buytenhuijs, A.; Cai, X. D.; Campanelli, M.; Capell, M.; Romeo, G. Cara; Caria, M.; Carlino, G.; Cartacci, A. M.; Casaus, J.; Castellini, G.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Cesaroni, F.; Chamizo, M.; Chan, A.; Chang, Y. H.; Chaturvedi, U. K.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chen, M.; Chiefari, G.; Chien, C. Y.; Choi, M. T.; Cifarelli, L.; Cindolo, F.; Civinini, C.; Clare, I.; Clare, R.; Cohn, H. O.; Coignet, G.; Colijn, A. P.; Colino, N.; Commichau, V.; Costantini, S.; Cotorobai, F.; de La Cruz, B.; Csilling, A.; Dai, T. S.; D'Alessandro, R.; de Asmundis, R.; de Boeck, H.; Degré, A.; Deiters, K.; Denes, P.; Denotaristefani, F.; Dibitonto, D.; Diemoz, M.; van Dierendonck, D.; di Lodovico, F.; Dionisi, C.; Dittmar, M.; Dominguez, A.; Doria, A.; Dorne, I.; Dova, M. T.; Drago, E.; Duchesneau, D.; Duinker, P.; Duran, I.; Dutta, S.; Easo, S.; Efremenko, Yu.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Erné, F. C.; Ernenwein, J. P.; Extermann, P.; Fabre, M.; Faccini, R.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Fenyi, B.; Ferguson, T.; Fernandez, D.; Ferroni, F.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Forconi, G.; Fredj, L.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gau, S. S.; Gentile, S.; Gerald, J.; Gheordanescu, N.; Giagu, S.; Goldfarb, S.; Goldstein, J.; Gong, Z. F.; Gougas, A.; Gratta, G.; Gruenewald, M. W.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Hartmann, B.; Hasan, A.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; van Hoek, W. C.; Hofer, H.; Hoorani, H.; Hou, S. R.; Hu, G.; Innocente, V.; Janssen, H.; Jenkes, K.; Jin, B. N.; Jones, L. W.; de Jong, P.; Josa-Mutuberria, I.; Kasser, A.; Khan, R. A.; Kamrad, D.; Kamyshkov, Yu.; Kapustinsky, J. S.; Karyotakis, Y.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, D.; Kim, J. K.; Kim, S. C.; Kim, Y. G.; Kinnison, W. W.; Kirkby, A.; Kirkby, D.; Kirkby, J.; Kiss, D.; Kittel, W.; Klimentov, A.; König, A. C.; Korolko, I.; Koutsenko, V.; Kraemer, R. W.; Krenz, W.; Kuijten, H.; Kunin, A.; de Guevara, P. Ladron; Landi, G.; Lapoint, C.; Lassila-Perini, K.; Laurikainen, P.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Lee, J. S.; Lee, K. Y.; Leggett, C.; Le Goff, J. M.; Leiste, R.; Leonardi, E.; Levtchenko, P.; Li, C.; Lieb, E.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, W.; Lu, Y. S.; Lübelsmeyer, K.; Luci, C.; Luckey, D.; Luminari, L.; Lustermann, W.; Ma, W. G.; Maity, M.; Majumder, G.; Malgeri, L.; Malinin, A.; Maña, C.; Mangla, S.; Marchesini, P.; Marin, A.; Martin, J. P.; Marzano, F.; Massaro, G. G. G.; McNally, D.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; von der Mey, M.; Mi, Y.; Mihul, A.; van Mil, A. J. W.; Mirabelli, G.; Mnich, J.; Molnar, P.; Monteleoni, B.; Moore, R.; Morganti, S.; Moulik, T.; Mount, R.; Müller, S.; Muheim, F.; Nagy, E.; Nahn, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Niessen, T.; Nippe, A.; Nisati, A.; Nowak, H.; Opitz, H.; Organtini, G.; Ostonen, R.; Pandoulas, D.; Paoletti, S.; Paolucci, P.; Park, H. K.; Pascale, G.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Peach, D.; Pei, Y. J.; Pensotti, S.; Perret-Gallix, D.; Petrak, S.; Pevsner, A.; Piccolo, D.; Pieri, M.; Pinto, J. C.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Postema, H.; Produit, N.; Prokofiev, D.; Rahal-Callot, G.; Rancoita, P. G.; Rattaggi, M.; Raven, G.; Razis, P.; Read, K.; Ren, D.; Rescigno, M.; Reucroft, S.; van Rhee, T.; Riemann, S.; Riemers, B. C.; Riles, K.; Rind, O.; Ro, S.; Robohm, A.; Rodin, J.; Rodriguez, F. J.; Roe, B. P.; Romero, L.; Rosier-Lees, S.; Rosselet, Ph.; van Rossum, W.; Roth, S.; Rubio, J. A.; Rykaczewski, H.; Salicio, J.; Sanchez, E.; Santocchia, A.; Sarakinos, M. E.; Sarkar, S.; Sassowsky, M.; Sauvage, G.; Schäfer, C.; Schegelsky, V.; Schmidt-Kaerst, S.; Schmitz, D.; Schmitz, P.; Schneegans, M.; Scholz, N.; Schopper, H.; Schotanus, D. J.; Schwenke, J.; Schwering, G.; Sciacca, C.; Sciarrino, D.; Sens, J. C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shukla, J.; Shumilov, E.; Shvorob, A.; Siedenburg, T.; Son, D.; Sopczak, A.; Soulimov, V.; Smith, B.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stone, H.; Stoyanov, B.; Straessner, A.; Strauch, K.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Susinno, G. F.; Suter, H.; Swain, J. D.; Tang, X. W.; Tauscher, L.; Taylor, L.; Ting, Samuel C. C.; Ting, S. M.; Tonutti, M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tuchscherer, H.; Tung, K. L.; Uchida, Y.; Ulbricht, J.; Uwer, U.; Valente, E.; van de Walle, R. T.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Vivargent, M.; Völkert, R.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Vorvolakos, A.; Wadhwa, M.; Wallraff, W.; Wang, J. C.; Wang, X. L.; Wang, Z. M.; Weber, A.; Wittgenstein, F.; Wu, S. X.; Wynhoff, S.; Xu, J.; Xu, Z. Z.; Yang, B. Z.; Yang, C. G.; Yao, X. Y.; Ye, J. B.; Yeh, S. C.; You, J. M.; Zalite, An.; Zalite, Yu.; Zemp, P.; Zeng, Y.; Zhang, Z.; Zhang, Z. P.; Zhou, B.; Zhou, Y.; Zhu, G. Y.; Zhu, R. Y.; Zichichi, A.; Ziegler, F.

    1997-02-01

    Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69+/-0.07 (stat.)+/-0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40+/-17% of the produced mesons are light-flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the π0 multiplicity in the weak charged hadronic current in b decays.

  10. Study of the Weak Charged Hadronic Current in b Decays

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alpat, B; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alverson, G; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Antreasyan, D; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banicz, K; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Borgia, B; Boucham, A; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Buytenhuijs, A O; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Caria, M; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chan, A; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Choi, M T; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Commichau, V; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; De Boeck, H; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dorne, I; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Fernández, D; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Janssen, H; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kim, S C; Kim, Y G; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kuijten, H; Kunin, A; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee Jae Sik; Lee, K Y; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lieb, E H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Mihul, A; Van Mil, A J W; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Morganti, S; Moulik, T; Mount, R; Müller, S; Muheim, F; Nagy, E; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nippe, A; Nisati, A; Nowak, H; Opitz, H; Organtini, G; Ostonen, R; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Pinto, J C; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Rahal-Callot, G; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riemers, B C; Riles, K; Rind, O; Ro, S; Robohm, A; Rodin, J; Rodríguez-Calonge, F J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Rykaczewski, H; Salicio, J; Sánchez, E; Santocchia, A; Sarakinos, M E; Sarkar, S; Sassowsky, M; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schmitz, P; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Sens, Johannes C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Sopczak, André; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Strauch, K; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonutti, M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Van de Walle, R T; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wittgenstein, F; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1997-01-01

    Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69$\\pm$0.07(stat.)$\\pm$0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40$\\pm$17\\% of the produced mesons are light--flavored tensor (L=1) mesons. This level of tensor meson production is consistent with the measurement of the $\\pi^0$ multiplicity in the weak charged hadronic current in b decays. \\end{abstract}

  11. Critical current studies of a HTS rectangular coil

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Z. [Department of Engineering, University of Cambridge (United Kingdom); Chudy, M., E-mail: Michal.chudy@stuba.sk [Graduate School of Technology Management, University of Pretoria (South Africa); Institute of Power and Applied Electrical Engineering, Slovak University of Technology in Bratislava (Slovakia); Ruiz, H.S. [Department of Engineering, University of Leicester, Leicester LE1 7RH (United Kingdom); Zhang, X.; Coombs, T. [Department of Engineering, University of Cambridge (United Kingdom)

    2017-05-15

    Highlights: • Unique square pancake coil was manufactured. • Measurements in relatively high magnetic field were performed. • Different sections of the coil were characterized. • Parts of the coil which are limiting critical current were identified. - Abstract: Nowadays, superconducting high field magnets are used in numerous applications due to their superior properties. High temperature superconductors (HTS) are usually used for production of circular pancake or racetrack coils. However different geometries of HTS coils might be required for some specific applications. In this study, the HTS coil wound on a rectangular frame was fully characterized in homogeneous DC background field. The study contains measurements of critical current angular dependencies. The critical current of the entire coil and two selected strands under different magnitudes and orientations of external magnetic fields are measured. The critical regions of the coil in different angular regimes are determined. This study brings better understanding of the in- field performance of HTS coils wound on frames with right-angles.

  12. An in vitro investigation of two currently marketed dentin tubule occlusion dentifrices.

    Science.gov (United States)

    Parkinson, Charles R; Willson, Richard J

    2011-01-01

    The objective of this study was to evaluate the relative level of dentin tubule occlusion afforded by two dentifrices specifically developed to occlude dentin tubules, following finger-applied dab-on application and by repeated brushing, in a longitudinal acid-challenge-based dentin disk model. The impact of a dietary acid alone (grapefruit juice) on the level of dentin tubule occlusion conferred by each product following dab-on application was also explored in a separate short-term stand-alone exploratory dentin disk-based in vitro study. For the longitudinal study, 120 bovine dentin discs, polished and etched in citric acid for two minutes to provide a smooth dentin surface with patent tubules, were divided into three treatment groups and subjected to a finger application of the dentifrice only, or a combination of finger application and brushing. Prior to and between treatments, the dentin samples were stored in saliva (for > 60 minutes). The test products were an 8% w/w strontium acetate dentifrice (currently marketed as Sensodyne Rapid Relief), an arginine-based dentifrice (marketed as Colgate Sensitive Pro-Relief), and deionized water. For the exploratory acid resistance study, 24 dentin samples were divided into two treatment groups. Treatment consisted of a single dab-on application with the test dentifrices to the hydrated surface of dentin, followed by exposure to either a 30-second or 10-minute grapefruit juice acid challenge. For both models, at the end of each treatment period, the samples were removed for scanning electron microscopy analysis and graded on a categorical visual scale. All data were analyzed statistically by unpaired t-test comparison. In the longitudinal (four-day) model, the strontium acetate-based dentifrice occluded dentin tubules significantly better than the currently marketed arginine-based dentifrice post-dab-on treatment and grapefruit juice challenge (p < 0.0001). At all other time points, the strontium acetate dentifrice

  13. Investigation of the current requirements engineering practices among software developers at the Universiti Utara Malaysia Information Technology (UUMIT) centre

    Science.gov (United States)

    Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Abdullah, Inam

    2016-08-01

    Requirements Engineering (RE) is a systemic and integrated process of eliciting, elaborating, negotiating, validating and managing of the requirements of a system in a software development project. UUM has been supported by various systems developed and maintained by the UUM Information Technology (UUMIT) Centre. The aim of this study was to assess the current requirements engineering practices at UUMIT. The main problem that prompted this research is the lack of studies that support software development activities at the UUMIT. The study is geared at helping UUMIT produce quality but time and cost saving software products by implementing cutting edge and state of the art requirements engineering practices. Also, the study contributes to UUM by identifying the activities needed for software development so that the management will be able to allocate budget to provide adequate and precise training for the software developers. Three variables were investigated: Requirement Description, Requirements Development (comprising: Requirements Elicitation, Requirements Analysis and Negotiation, Requirements Validation), and Requirement Management. The results from the study showed that the current practice of requirement engineering in UUMIT is encouraging, but still need further development and improvement because a few RE practices were seldom practiced.

  14. Metabolic investigation in Gluconacetobacter xylinus and its bacterial cellulose production under a direct current electric field

    Directory of Open Access Journals (Sweden)

    Miao eLiu

    2016-03-01

    Full Text Available The effects of a direct current (DC electric field on the growth and metabolism of Gluconacetobacter xylinus were investigated in static culture. When a DC electric field at 10 mA was applied using platinum electrodes to the culture broth, bacterial cellulose (BC production was promoted in 12 hours (h but was inhibited in the last 12 h as compared to the control (without DC electric field. At the cathode, the presence of the hydrogen generated a strong reductive environment that is beneficial to cell growth. As compared to the control, the activities of glycolysis and tricarboxylic acid cycle, as well as BC productivity were observed to be slightly higher in the first 12 h. However, due to the absence of sufficient oxygen, lactic acid was accumulated from pyruvic acid at 18 h, which was not in favor of BC production. At the anode, DC inhibited cell growth in 6 h when compared to the control. The metabolic activity in G. xylinus was inhibited through the suppression of the tricarboxylic acid cycle and glycolysis. At 18-24 h, cell density was observed to decrease, which might be due to the electrolysis of water that significantly dropped the pH of cultural broth far beyond the optimal range. Meanwhile, metabolites for self-protection were accumulated, for instance proline, glutamic acid, gluconic acid and fatty acids. Notably, the accumulation of gluconic acid and lactic acid made it a really tough acid stress to cells at the anode and finally led to depression of cell growth.

  15. An Investigation of the Variety and Complexity of Statistical Methods Used in Current Internal Medicine Literature.

    Science.gov (United States)

    Narayanan, Roshni; Nugent, Rebecca; Nugent, Kenneth

    2015-10-01

    Accreditation Council for Graduate Medical Education guidelines require internal medicine residents to develop skills in the interpretation of medical literature and to understand the principles of research. A necessary component is the ability to understand the statistical methods used and their results, material that is not an in-depth focus of most medical school curricula and residency programs. Given the breadth and depth of the current medical literature and an increasing emphasis on complex, sophisticated statistical analyses, the statistical foundation and education necessary for residents are uncertain. We reviewed the statistical methods and terms used in 49 articles discussed at the journal club in the Department of Internal Medicine residency program at Texas Tech University between January 1, 2013 and June 30, 2013. We collected information on the study type and on the statistical methods used for summarizing and comparing samples, determining the relations between independent variables and dependent variables, and estimating models. We then identified the typical statistics education level at which each term or method is learned. A total of 14 articles came from the Journal of the American Medical Association Internal Medicine, 11 from the New England Journal of Medicine, 6 from the Annals of Internal Medicine, 5 from the Journal of the American Medical Association, and 13 from other journals. Twenty reported randomized controlled trials. Summary statistics included mean values (39 articles), category counts (38), and medians (28). Group comparisons were based on t tests (14 articles), χ2 tests (21), and nonparametric ranking tests (10). The relations between dependent and independent variables were analyzed with simple regression (6 articles), multivariate regression (11), and logistic regression (8). Nine studies reported odds ratios with 95% confidence intervals, and seven analyzed test performance using sensitivity and specificity calculations

  16. 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

  17. A study of eddy current measurement (1986-1987)

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, R.S.; Armstrong, K.P.

    1989-06-22

    A study was conducted in 1986 to evaluate a modified eddy current system for measuring copper thickness on Kapton. Results showed a measurement error of 0.42 {mu}in. for a thickness range of 165 to 170 {mu}in. and a measurement variability of 3.2 {mu}in.

  18. Cartography and Population Geography as Current Events: A Case Study

    Science.gov (United States)

    Comenetz, Joshua

    2003-01-01

    The Sanders housing lawsuit in Pennsylvania provides a case study of how to incorporate current events into the teaching of cartography or population geography at the high school or college level. Settlement of the Sanders case resulted in the release of information about the segregation of public housing by race in the Pittsburgh area. The issues…

  19. Investigation of the current break-down phenomena in solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, S.K.; Srinivasamurthy, N.; Agrawal, B.L. [Power Systems Group, ISRO Satellite Centre, Bangalore (India)

    1996-08-15

    Observed reverse current-voltage characteristics of the single crystal silicon and gallium arsenide solar cells have been analyzed. Physical mechanisms behind the junction break-down in silicon cells and current break-down in gallium arsenide cells have been identified. Preliminary estimates of the diffusion capacitance in GaAs cells have been presented

  20. Differential Thermostimulated Discharge Current Method for Studying Electrets

    Science.gov (United States)

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

    2010-01-01

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

  1. Study on Fault Current of DFIG during Slight Fault Condition

    Directory of Open Access Journals (Sweden)

    Xiangping Kong

    2013-04-01

    Full Text Available In order to ensure the safety of DFIG when severe fault happens, crowbar protection is adopted. But during slight fault condition, the crowbar protection will not trip, and the DFIG is still excited by AC-DC-AC converter. In this condition, operation characteristics of the converter have large influence on the fault current characteristics of DFIG. By theoretical analysis and digital simulation, the fault current characteristics of DFIG during slight voltage dips are studied. And the influence of controller parameters of converter on the fault current characteristics is analyzed emphatically. It builds a basis for the construction of relay protection which is suitable for the power gird with accession of DFIG.

  2. DNA typing in forensic medicine and in criminal investigations: a current survey

    Science.gov (United States)

    Benecke, Mark

    Since 1985 DNA typing of biological material has become one of the most powerful tools for personal identification in forensic medicine and in criminal investigations [1-6]. Classical DNA 〝fingerprinting'' is increasingly being replaced by polymerase chain reaction (PCR) based technology which detects very short polymorphic stretches of DNA [7-15]. DNA loci which forensic scientists study do not code for proteins, and they are spread over the whole genome [16, 17]. These loci are neutral, and few provide any information about individuals except for their identity. Minute amounts of biological material are sufficient for DNA typing. Many European countries are beginning to establish databases to store DNA profiles of crime scenes and known offenders. A brief overview is given of past and present DNA typing and the establishment of forensic DNA databases in Europe.

  3. An investigation of environmental factors associated with the current and proposed jetty systems at Belle Pass, Louisiana

    Science.gov (United States)

    Dantin, E. J.; Whitehurst, C. A.; Durbin, W. T.

    1974-01-01

    The history of the existing jetty system at Belle Pass was investigated to determine its past effect on the littoral currents and beach erosion. Present flow patterns and erosion rates were also studied, along with the prevailing recession rates of local beaches not influenced by the jetty system. Aerial photographs and maps were used in conjunction with periodic hydraulic measurements, ground observations, and physical measurements of beach erosion. A scale model was constructed to further the study of flow patterns and velocities. It is shown that the existing jetty has not adversely affected the coastline in the area; erosive processes have been retarded by the jetty and its companion groin. Future erosion patterns are predicted, and projected effects of the proposed jetty system are given.

  4. Investigations into the Effect of Current Velocity on Amidoxime-Based Polymeric Uranium Adsorbent Performance

    Energy Technology Data Exchange (ETDEWEB)

    Gill, Gary A. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Kuo, Li-Jung [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Strivens, Jonathan E. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Wood, Jordana R. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Schlafer, Nicholas J. [Pacific Northwest National Lab. (PNNL), Sequim, WA (United States). Marine Sciences Lab.; Tsouris, Costas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Environmental Sciences Division; Ladshaw, Austin [Georgia Inst. of Technology, Atlanta, GA (United States); Yiacoumi, Sotira [Georgia Inst. of Technology, Atlanta, GA (United States)

    2015-12-01

    The Fuel Resources Program at the U.S. Department of Energy’s (DOE), Office of Nuclear Energy (DOE-NE) is developing adsorbent technology to extract uranium from seawater. This technology is being developed to provide a sustainable and economically viable supply of uranium fuel for nuclear reactors (DOE, 2010). Among the key environmental variables to understand for adsorbent deployment in the coastal ocean is what effect flow-rates or linear velocity has on uranium adsorption capacity. The goal is to find a flow conditions that optimize uranium adsorption capacity in the shortest exposure time. Understanding these criteria will be critical in choosing a location for deployment of a marine adsorbent farm. The objective of this study was to identify at what linear velocity the adsorption kinetics for uranium extraction starts to drop off due to limitations in mass transport of uranium to the surface of the adsorbent fibers. Two independent laboratory-based experimental approaches using flow-through columns and recirculating flumes for adsorbent exposure were used to assess the effect of flow-rate (linear velocity) on the kinetic uptake of uranium on amidoxime-based polymeric adsorbent material. Time series observations over a 56 day period were conducted with flow-through columns over a 35-fold range in linear velocity from 0.29 to 10.2 cm/s, while the flume study was conducted over a narrower 11-fold range, from 0.48 to 5.52 cm/s. These ranges were specifically chosen to focus on the lower end of oceanic currents and expand above and below the linear velocity of ~ 2.5 cm/s adopted for marine testing of adsorbent material at PNNL.

  5. Experimental and theoretical investigations on the singularity of the intensity factor of the current in high temperature superconductors

    Science.gov (United States)

    Zhang, Xingyi; Huang, Yi; Zhou, Jun; Zhou, Youhe

    2013-08-01

    This paper presents experimental and analytical investigations into the distribution of current around a through-edge crack located in an infinitely long cylindrical high temperature superconductor (HTS) on the basis of the Bean model. Current distributions around the crack in the HTS without deformation are obtained by a simple conformal mapping. It is shown that the current is singular at the tip of the crack. An intensity factor of the current is introduced to characterize the singularity, the order of which is equal to -1. Additionally, an experimental verification according to the trapped field distributions around the crack is carried out, and the experimental results show little difference with the theoretical analysis.

  6. INVESTIGATION OF MICROPROCESSOR CURRENT PROTECTION LINES WITH IMPROVED INDICES OF TECHNICAL PERFECTION

    Directory of Open Access Journals (Sweden)

    E. V. Buloichyk

    2014-01-01

    Full Text Available Technical perfection improvement of microprocessor current protection of distribution networks lines is provided by introduction of asymmetrical fault mode determination and fault location functions in the algorithm of its functioning. As a result of computing experiment the basic indices of the technical perfection of current protection have been obtained in the paper. The paper proves high efficiency of the proposed methods that ensure selective and proper operation in the different modes of the controlled line.

  7. Experimental Study on Current Decay Characteristics of Persistent Current HTS Magnet by Alternating Magnetic Field

    Science.gov (United States)

    Park, Young Gun; Lee, Chang Young; Hwang, Young Jin; Lee, Woo Seung; Lee, Jiho; Jo, Hyun Chul; Chung, Yoon Do; Ko, Tae Kuk

    This paper deals with a current decay characteristics of a high temperature superconducting (HTS) magnet operated in persistent current mode (PCM). In superconducting synchronous machine applications such as linear synchronous motor (LSM), the superconducting coil is designed to operate in the PCM to obtain steady magnetic field with DC transport current. This superconducting magnet operates on a direct current, but it can be exposed to alternating magnetic field due to the armature winding. When the magnet is subjected to an external time-varying magnetic field, it is possible to result in a decay of the current in PCM system due to AC loss. In this research, a PCM system with armature coil which generates time-varying magnetic field was fabricated to verify current decay characteristics by external alternating magnetic field. The current decay rate was measured by using a hall sensor as functions of amplitude and frequency of armature coil.

  8. Investigating the effects of the interface defects on the gate leakage current in MOSFETs

    Science.gov (United States)

    Mao, Ling-Feng

    2008-08-01

    The effects of the interface defects on the gate leakage current have been numerically modeled. The results demonstrate that the shallow and deep traps have different effects on the dependence relation of the stress-induced leakage current on the oxide electric field in the regime of direct tunneling, whereas both traps keep the same dependence relation in the regime of Fowler-Nordheim tunneling. The results also shows that the stress-induced leakage current will be the largest at a moderate oxide voltage for the electron interface traps but it increases with the decreasing oxide voltage for the hole interface traps. The results illustrate that the stress-induced leakage current strongly depends on the location of the electron interface traps but it weakly depends on the location of the hole interface traps. The increase in the gate leakage current caused by the electron interface traps can predict the increase, then decrease in the stress-induced leakage current, with decreasing oxide thickness, which is observed experimentally. And the electron interface trap level will have a large effect on the peak height and position.

  9. An investigation of counter-current flow in porous media with history-dependent modeling

    Science.gov (United States)

    Li, G.; Grader, A. S.; Halleck, P. H.; Karpyn, Z. T.

    2003-04-01

    Counter-current fluid flow occurs in many reservoir processes. It is important to understand and model these processes in order to operate them effectively. Both drainage and imbibition processes exist simultaneously when counter-current flow occurs. It has thus proven difficult to model this type of flow, especially when fluid banks form. Previously, counter-current flow experiments have been done in glass bead packs and the spatial and temporal saturation distributions obtained with X-ray computed tomography (CT). In the current paper, a new saturation-history-dependent approach has been developed to simulate the experiments. Hysteresis in both capillary pressure and relative permeabilities is considered during the process of matching the simulation results to experimental data. Capillary pressure and relative permeabilities are extracted with the aid of a deterministic reservoir simulator. During the history matching process, a family of curves (called scanning curves) is constructed connecting the two branches of the capillary hystersis loop. Each grid block of the sample is assigned a different scanning curve according to its saturation history. Simulation of the experiments reproduced two-dimensional saturation distributions over time with good accuracy. Similar results could not be obtained with traditional simulation using only one capillary pressure curve. History-dependent modeling successfully predicted cross-diameter counter-current flow in a cylindrical geometry. The parameters used in the single capillary pressure method are the average of the parameters used in the history-dependent method. Total effective mobility controls the flow process, being smaller in counter-current flow than in co-current flow. Experiments documented in the literature that exhibited formation of fluid banks were also successfully simulated. We anticipate that application of this method will improve the prediction of full-scale fluid flow processes such as ground water

  10. Current methods for studying dynamic processes in the ionosphere

    Science.gov (United States)

    Filipp, Nikolai D.; Blaunshtein, Natan Sh.; Erukhimov, Lev M.; Ivanov, Vladimir A.; Uriadov, Valerii P.

    Current experimental and theoretical data relevant to the study of dynamic processes in the ionospheric plasma using state-of-the-art methods are summarized. The methods used include linear FM sounding, partial radio wave reflection, oblique-incidence radio wave scattering, radio wave heating of the ionosphere, plasma injection, and computer simulation of physical processes. For each specific method, experimental data are compared against theoretical predictions and numerical calculations.

  11. Pancreatic exocrine studies in intact animals: historic and current methods.

    Science.gov (United States)

    Niebergall-Roth, E; Teyssen, S; Singer, M V

    1997-12-01

    This report presents a review of the historic and current methods for performing pancreatic exocrine studies in intact animals. Special emphasis is given to the various surgical procedures--pancreatic fistulas, duodenal pouches, and duodenal fistulas--and practice of collecting pancreatic secretion in dogs. Procedures in other animal species--rat, cat, pig, rabbit, cattle, sheep, and horse--also are specified. The advantages and disadvantages, as well as the indications and limitations of the distinct methods, are discussed.

  12. Investigation of lower hybrid current drive during H-mode in EAST tokamak

    Institute of Scientific and Technical Information of China (English)

    Li Miao-Hui; Liu Fu-Kun; Wang Mao; Xu Han-Dong; Wan Bao-Nian; Ding Bo-Jiang; Kong Er-Hua; Zhang Lei; Zhang Xin-Jun; Qian Jin-Ping; Yan Ning; Han Xiao-Feng; Shan Jia-Fang

    2011-01-01

    H-mode discharges with lower hybrid current drive (LHCD) alone are achieved in EAST divertor plasma over a wide parameter range.These H-mode discharges are characterized by a sudden drop in Dα emission and a spontaneous rise in main plasma density.Good lower hybrid (LH) coupling during H-mode is obtained by putting the plasma close to the antenna and by injecting D2 gas from a pipe near the grill mouse.The analysis of lower hybrid current drive properties shows that the LH deposition profile shifts off axis during H-mode,and current drive (CD) efficiency decreases due to the increase in density.Modeling results of H-mode discharges with a general ray tracing code GENRAY are reported.

  13. Investigation of cathodic current collection in lithium/manganese dioxide cells by electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Merritt, D.R.; Schmidt, C.L. [Medtronic, Inc., Minneapolis, MN (United States)

    1994-12-31

    Contact impedance between pressed composite manganese dioxide cathodes and current collectors has been shown to play an important role in the overall impedance of primary Li/MnO{sub 2} cells. Specifically, this impedance is manifested by an arc in the complex-plane impedance plot, representative of a parallel resistive/capacitive combination, This paper presents the results of a systematic series of experiments designed to better define the relationship between cathodic current collector configuration and cell impedance. A refined equivalent circuit model of the Li/MnO{sub 2} cell is also presented.

  14. Ways of Thinking Globalisation--Insights into a Currently Running Investigation of Students' Ideas of Globalisation

    Science.gov (United States)

    Fischer, Sebastian; Fischer, Florian; Kleinschmidt, Malte; Lange, Dirk

    2014-01-01

    The investigation is about which ideas ninth form students at grammar schools and secondary modern schools have about globalisation. It shall be investigated if the perception of and judgement on globalisation-connected contexts happens along social structure-specific patterns. At first, by way of a questionnaire, the field of ideas is supposed to…

  15. Current Status of Integral Medical Study on Endometriosis

    Institute of Scientific and Technical Information of China (English)

    YU Chao-qin (俞超芹); YU Jin (俞瑾)

    2003-01-01

    @@ Endometriosis (EM), an estrogen dependent disease that comes from the planting of endometrial gland and stroma outside the uterine cavity, is characterized by invasiveness, wide planting and liability to relapse. It has been proved by recent studies that the pathogenesis of EM has its genetic background and is closely related with neuro-, endocrino- and immuno-factors. There has been great progress in the treatment of EM, but the clinical effect is not yet satisfactory. Traditional Chinese medicine (TCM) has definitely played its role in EM treatment. In this article, the current status of integral medical study on EM is reviewed.

  16. Current-voltage behaviour of bipolar membranes in concentrated salt solutions investigated with chronopotentiometry

    NARCIS (Netherlands)

    Wilhelm, F.G.; Vegt, van der N.F.A.; Strathmann, H.; Wessling, M.

    2002-01-01

    Chronopotentiometry is used as a tool to obtain detailed information on the transport behaviour of the bipolar membrane BP-1 in solutions of high sodium chloride concentration above the limiting current density. We discuss critically the interpretation of the observed transition times. The occurrenc

  17. How Do Clinicians Learn About Knowledge Translation? An Investigation of Current Web-Based Learning Opportunities.

    Science.gov (United States)

    Damarell, Raechel A; Tieman, Jennifer J

    2017-07-13

    Clinicians are important stakeholders in the translation of well-designed research evidence into clinical practice for optimal patient care. However, the application of knowledge translation (KT) theories and processes may present conceptual and practical challenges for clinicians. Online learning platforms are an effective means of delivering KT education, providing an interactive, time-efficient, and affordable alternative to face-to-face education programs. This study investigates the availability and accessibility of online KT learning opportunities for health professionals. It also provides an analysis of the types of resources and associated disciplines retrieved by a range of KT synonyms. We searched a range of bibliographic databases and the Internet (Google advanced option) using 9 KT terms to identify online KT learning resources. To be eligible, resources had to be free, aimed at clinicians, educational in intent, and interactive in design. Each term was searched using two different search engines. The details of the first 100 websites captured per browser (ie, n=200 results per term) were entered into EndNote. Each site was subsequently visited to determine its status as a learning resource. Eligible websites were appraised for quality using the AACODS (Authority, Accuracy, Coverage, Objectivity, Date, Significance) tool. We identified 971 unique websites via our multiple search strategies. Of these, 43 were health-related and educational in intent. Once these sites were evaluated for interactivity, a single website matched our inclusion criteria (Dementia Knowledge Translation Learning Centre). KT is an important but complex system of processes. These processes overlap with knowledge, practice, and improvement processes that go by a range of different names. For clinicians to be informed and competent in KT, they require better access to free learning opportunities. These resources should be designed from the viewpoint of the clinician, presenting KT

  18. Investigations of Beam Dynamics Issues at Current and Future Hadron Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James [Univ. of New Mexico, Albuquerque, NM (United States); Lau, Stephen [Univ. of New Mexico, Albuquerque, NM (United States); Heinemann, Klaus [Univ. of New Mexico, Albuquerque, NM (United States); Bizzozero, David [Univ. of New Mexico, Albuquerque, NM (United States)

    2015-03-12

    Final Report Abstract for DE-FG02-99ER4110, May 15, 2011- October 15, 2014 There is a synergy between the fields of Beam Dynamics (BD) in modern particle accelerators and Applied Mathematics (AMa). We have formulated significant problems in BD and have developed and applied tools within the contexts of dynamical systems, topological methods, numerical analysis and scientific computing, probability and stochastic processes, and mathematical statistics. We summarize the three main areas of our AMa work since 2011. First, we continued our study of Vlasov-Maxwell systems. Previously, we developed a state of the art algorithm and code (VM3@A) to calculate coherent synchrotron radiation in single pass systems. In this cycle we carefully analyzed the major expense, namely the integral-over-history (IOH), and developed two approaches to speed up integration. The first strategy uses a representation of the Bessel function J0 in terms of exponentials. The second relies on “local sequences” developed recently for radiation boundary conditions, which are used to reduce computational domains. Although motivated by practicality, both strategies involve interesting and rather deep analysis and approximation theory. As an alternative to VM3@A, we are integrating Maxwell’s equations by a time-stepping method, bypass- ing the IOH, using a Discontinuous Galerkin (DG) method. DG is a generalization of Finite Element and Finite Volume methods. It is spectrally convergent, unlike the commonly used Finite Difference methods, and can handle complicated vacuum chamber geometries. We have applied this in several contexts and have obtained very nice results including an explanation of an experiment at the Canadian Light Source, where the geometry is quite complex. Second, we continued our study of spin dynamics in storage rings. There is much current and proposed activity where spin polarized beams are being used in testing the Standard Model and its modifications. Our work has focused

  19. Magnetic investigations for studying planetary interiors

    Directory of Open Access Journals (Sweden)

    A. De Santis

    1994-06-01

    Full Text Available Most of the magnetic methods used for investigating planetary interiors are based on the reasonable hypothesis that the mechanism for the origin of the field is an Earth-like hydromagnetic dynamo: in this case the planet has an electrically conducting fluid shell within it as in the case of the Earth's core. The present paper describes several techniques of planetary magnetic investigation which give important clues on the internal constitution of planets. Some considerations on the possible mechanisms for maintaining a dynamo and simple concepts with the help of a few non-dimensional numbers are also introduced and discussed. Then some fundamental relationships are given in order to relate the planetary magnetism to other physical parameters, such as angular rotation, core dimensions etc. It finally summarizes some results available for the planets of the Solar System.

  20. Investigating Current Status of English for Academic Purposes (EAP in Iran; Revisiting ESP Specificity Continuum

    Directory of Open Access Journals (Sweden)

    Marjan Vosoughi

    2013-05-01

    Full Text Available The EAP textbooks which are currently taught in Iranian universities don't seem to satisfy the necessary requirements current in new enquires of EAP research.  An EAP book sample from SAMT 1 publications for the students of medicine was chosen for a critical analysis on three criteria including: evaluating the objectives, reviewing the content, and evaluating the overall structure. The exploratory reviews showed that there must be major changes in EAP for medical students of SAMT to meet the specific needs of the target group above. In this article, the general status of ESP material development approaches is also depicted diachronically in order to evaluate the present situation in Iran against appropriate recent approaches towards EAP material development in the world. Recommended implications of some kind are presented throughout the various parts of the present survey.     Keywords: EAP materials, English for medical purposes (EMP, specificity continuum, material development

  1. GEOS-3 ocean current investigation using radar altimeter profiling. [Gulf Stream surface topography

    Science.gov (United States)

    Leitao, C. D.; Huang, N. E.; Parra, C. G.

    1978-01-01

    Both quasi-stationary and dynamic departures from the marine geoid were successfully detected using altitude measurements from the GEOS-3 radar altimeter. The quasi-stationary departures are observed either as elevation changes in single pass profiles across the Gulf Stream or at the crowding of contour lines at the western and northern areas of topographic maps generated using altimeter data spanning one month or longer. Dynamic features such as current meandering and spawned eddies can be monitored by comparing monthly mean maps. Comparison of altimeter inferred eddies with IR detected thermal rings indicates agreement of the two techniques. Estimates of current velocity are made using derived slope estimates in conjunction with the geostrophic equation.

  2. Investigations on the performances of the electrical generator of a rim-driven marine current turbine”

    OpenAIRE

    2008-01-01

    In this paper, the electrical generator of a rim-driven horizontal-axis current turbine is modeled in detail. Its main characteristics and performances are evaluated (efficiency, mass, cost, etc). This generator is of permanent magnet direct-driven synchronous type and is connected to a variable speed power electronics drive. It is then compared to a more traditional technology (a pod generator) in terms of mass and cost for a common set of specification. In addition, due to the specific geom...

  3. Investigations on the electrical current-voltage response in protein light receptors

    CERN Document Server

    Alfinito, E; Reggiani, L

    2014-01-01

    We report a theoretical/computational approach for modeling the current-voltage characteristics of sensing proteins. The modeling is applied to a couple of transmembrane proteins, bacteriorhodopsin and proteorhodopsin, sensitive to visible light and promising biomaterials for the development of a new generation of photo-transducers. The agreement between theory and experiments sheds new light on the microscopic interpretation of charge transfer in proteins and biological materials in general.

  4. Experimental investigation of quasiperiodic-chaotic-quasiperiodic-chaotic transition in a direct current magnetron sputtering plasma

    Energy Technology Data Exchange (ETDEWEB)

    Sabavath, Gopi Kishan; Banerjee, I.; Mahapatra, S. K., E-mail: skmahapatra@bitmesra.ac.in [Plasma Laboratory, Department of Physics, Birla Institute of Technology-Mesra, Ranchi 835215 (India); Shaw, Pankaj Kumar; Sekar Iyengar, A. N. [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)

    2015-08-15

    Floating potential fluctuations from a direct current magnetron sputtering plasma have been analysed using time series analysis techniques like phase space plots, power spectra, frequency bifurcation plot, etc. The system exhibits quasiperiodic-chaotic-quasiperiodic-chaotic transitions as the discharge voltage was increased. The transitions of the fluctuations, quantified using the largest Lyapunov exponent, have been corroborated by Hurst exponent and the Shannon entropy. The Shannon entropy is high for quasiperiodic and low for chaotic oscillations.

  5. Investigation of data retention under current bias for phase change memory

    Science.gov (United States)

    Lu, Yao-Yao; Cai, Dao-Lin; Chen, Yi-Feng; Wang, Yue-Qing; Wei, Hong-Yang; Huo, Ru-Ru; Song, Zhi-Tang

    2016-10-01

    With Phase-change memory (PCM), information can be stored as different resistance states even when not powered. In order to accurately characterize the reliability of PCM devices, data retention has to be tested carefully. In this paper, a new test method is applied to measure the data retention of T-shaped PCM devices. This method makes it possible to accelerate crystallization in the amorphous area by using current bias. The new method works based on the field-induced crystallization theory, and could be able to gather fast and detailed information about high-resistance state's failure process, and at the same time, it could avoid issues related to high temperature. Experimental data for T-shaped PCM devices based on Ge2Sb2Te5 are presented and analyzed. An exponential trend-line of failure time t versus reciprocal bias current 1/I shows only negligible deviation of the measured data points, enabling the extrapolation of the retention behavior for ten-year lifetime. A maximum disturb current value of 5.08 μA is extracted to guarantee the ten years data retention requirement for PCM applications.

  6. Investigation of iron current measurement to detect combustion quality; Ion denryu ni yoru nensho jotai kenshutsu no kento

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, K.; Mogi, K. [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    The possibility and problems were investigated in detecting the combustion quality by means of ion current measured at the spark plug. The ion current has two peaks during one combustion stroke; first peak is generated by flame around the spark plug just after ignition and second one appears with the rise in temperature of burned gases. As the result of investigations, it was confirmed that the first ion peak might be useful to forecast the combustion quality, but it would be hard to practice owing to the spark duration. And the second peak offered the information of combustion chamber pressure. 4 refs., 12 figs., 1 tab.

  7. Simulation and mechanistic investigation of the arrhythmogenic role of the late sodium current in human heart failure.

    Directory of Open Access Journals (Sweden)

    Beatriz Trenor

    Full Text Available Heart failure constitutes a major public health problem worldwide. The electrophysiological remodeling of failing hearts sets the stage for malignant arrhythmias, in which the role of the late Na(+ current (I(NaL is relevant and is currently under investigation. In this study we examined the role of I(NaL in the electrophysiological phenotype of ventricular myocytes, and its proarrhythmic effects in the failing heart. A model for cellular heart failure was proposed using a modified version of Grandi et al. model for human ventricular action potential that incorporates the formulation of I(NaL. A sensitivity analysis of the model was performed and simulations of the pathological electrical activity of the cell were conducted. The proposed model for the human I(NaL and the electrophysiological remodeling of myocytes from failing hearts accurately reproduce experimental observations. The sensitivity analysis of the modulation of electrophysiological parameters of myocytes from failing hearts due to ion channels remodeling, revealed a role for I(NaL in the prolongation of action potential duration (APD, triangulation of the shape of the AP, and changes in Ca(2+ transient. A mechanistic investigation of intracellular Na(+ accumulation and APD shortening with increasing frequency of stimulation of failing myocytes revealed a role for the Na(+/K(+ pump, the Na(+/Ca(2+ exchanger and I(NaL. The results of the simulations also showed that in failing myocytes, the enhancement of I(NaL increased the reverse rate-dependent APD prolongation and the probability of initiating early afterdepolarizations. The electrophysiological remodeling of failing hearts and especially the enhancement of the I(NaL prolong APD and alter Ca(2+ transient facilitating the development of early afterdepolarizations. An enhanced I(NaL appears to be an important contributor to the electrophysiological phenotype and to the dysregulation of [Ca(2+](i homeostasis of failing myocytes.

  8. Paying research participants: a study of current practices in Australia.

    Science.gov (United States)

    Fry, C L; Ritter, A; Baldwin, S; Bowen, K J; Gardiner, P; Holt, T; Jenkinson, R; Johnston, J

    2005-09-01

    To examine current research payment practices and to inform development of clearer guidelines for researchers and ethics committees. Exploratory email based questionnaire study of current research participant reimbursement practices. A diverse sample of organisations and individuals were targeted. Australia. Contacts in 84 key research organisations and select electronic listservers across Australia. A total of 100 completed questionnaires were received with representations from a variety of research areas (for example, market, alcohol and drug, medical, pharmaceutical and social research). Open-ended and fixed alternative questions about type of research agency; type of research; type of population under study; whether payment is standard; amounts and mechanisms of payment; factors taken into account when deciding on payment practices; and whether payment policies exist. Reimbursement practice is highly variable. Where it occurs (most commonly for drug dependent rather than health professional or general population samples) it is largely monetary and is for time and out-of-pocket expenses. Ethics committees were reported to be often involved in decision making around reimbursement. Research subject payment practices vary in Australia. Researchers who do provide payments to research participants generally do so without written policy and procedures. Ethics committees have an important role in developing guidelines in this area. Specific guidelines are needed considering existing local policies and procedures; payment models and their application in diverse settings; case study examples of types and levels of reimbursement; applied definitions of incentive and inducement; and the rationale for diverse payment practices in different settings.

  9. Investigations of Beam Dynamics Issues at Current and Future Hadron Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Ellison, James [Univ. of New Mexico, Albuquerque, NM (United States); Lau, Stephen [Univ. of New Mexico, Albuquerque, NM (United States); Heinemann, Klaus [Univ. of New Mexico, Albuquerque, NM (United States); Bizzozero, David [Univ. of New Mexico, Albuquerque, NM (United States)

    2015-03-12

    Final Report Abstract for DE-FG02-99ER4110, May 15, 2011- October 15, 2014 There is a synergy between the fields of Beam Dynamics (BD) in modern particle accelerators and Applied Mathematics (AMa). We have formulated significant problems in BD and have developed and applied tools within the contexts of dynamical systems, topological methods, numerical analysis and scientific computing, probability and stochastic processes, and mathematical statistics. We summarize the three main areas of our AMa work since 2011. First, we continued our study of Vlasov-Maxwell systems. Previously, we developed a state of the art algorithm and code (VM3@A) to calculate coherent synchrotron radiation in single pass systems. In this cycle we carefully analyzed the major expense, namely the integral-over-history (IOH), and developed two approaches to speed up integration. The first strategy uses a representation of the Bessel function J0 in terms of exponentials. The second relies on “local sequences” developed recently for radiation boundary conditions, which are used to reduce computational domains. Although motivated by practicality, both strategies involve interesting and rather deep analysis and approximation theory. As an alternative to VM3@A, we are integrating Maxwell’s equations by a time-stepping method, bypass- ing the IOH, using a Discontinuous Galerkin (DG) method. DG is a generalization of Finite Element and Finite Volume methods. It is spectrally convergent, unlike the commonly used Finite Difference methods, and can handle complicated vacuum chamber geometries. We have applied this in several contexts and have obtained very nice results including an explanation of an experiment at the Canadian Light Source, where the geometry is quite complex. Second, we continued our study of spin dynamics in storage rings. There is much current and proposed activity where spin polarized beams are being used in testing the Standard Model and its modifications. Our work has focused

  10. Current Proteomic Methods to Investigate the Dynamics of Histone Turnover in the Central Nervous System

    Science.gov (United States)

    Farrelly, L.A.; Dill, B.D.; Molina, H.; Birtwistle, M.R.; Maze, I.

    2016-01-01

    Characterizing the dynamic behavior of nucleosomes in the central nervous system is vital to our understanding of brain-specific chromatin-templated processes and their roles in transcriptional plasticity. Histone turnover—the complete loss of old, and replacement by new, nucleosomal histones—is one such phenomenon that has recently been shown to be critical for cell-type-specific transcription in brain, synaptic plasticity, and cognition. Such revelations that histones, long believed to static proteins in postmitotic cells, are highly dynamic in neurons were only possible owing to significant advances in analytical chemistry-based techniques, which now provide a platform for investigations of histone dynamics in both healthy and diseased tissues. Here, we discuss both past and present proteomic methods (eg, mass spectrometry, human “bomb pulse labeling”) for investigating histone turnover in brain with the hope that such information may stimulate future investigations of both adaptive and aberrant forms of “neuroepigenetic” plasticity. PMID:27423867

  11. Current Mathematical Methods Used in QSAR/QSPR Studies

    Directory of Open Access Journals (Sweden)

    Peixun Liu

    2009-04-01

    Full Text Available This paper gives an overview of the mathematical methods currently used in quantitative structure-activity/property relationship (QASR/QSPR studies. Recently, the mathematical methods applied to the regression of QASR/QSPR models are developing very fast, and new methods, such as Gene Expression Programming (GEP, Project Pursuit Regression (PPR and Local Lazy Regression (LLR have appeared on the QASR/QSPR stage. At the same time, the earlier methods, including Multiple Linear Regression (MLR, Partial Least Squares (PLS, Neural Networks (NN, Support Vector Machine (SVM and so on, are being upgraded to improve their performance in QASR/QSPR studies. These new and upgraded methods and algorithms are described in detail, and their advantages and disadvantages are evaluated and discussed, to show their application potential in QASR/QSPR studies in the future.

  12. Current management of bronchiectasis: review and 3 case studies.

    Science.gov (United States)

    Silverman, Enid; Ebright, Linda; Kwiatkowski, Marianne; Cullina, Joanne

    2003-01-01

    Bronchiectasis is the abnormal, irreversible dilatation of diseased bronchi. Permanently dilated airways, usually in the medium-sized bronchi, are inflamed and often obstructed with thick, purulent secretions. Known causative factors include postinfection bronchial damage, postinhalation injury, hypersensitivity reactions, and congenital airway obstructive disorders. Typical symptoms include sputum overproduction, fever, pleurisy, dyspnea, and chronic cough. Diagnosis involves radiographic studies and pulmonary function testing. Treatment includes oral, aerosolized, or intravenous antibiotic therapy according to the severity of the exacerbation, and mucus clearance by means of bronchial hygiene assistive devices, chest physiotherapy, postural drainage, and high-frequency chest compression. We present a review of bronchiectasis and offer 3 case studies illustrating current management of different presentations, including use of aerosolized antibiotics for patients infected with Pseudomonas aeruginosa. Although an adjunctive program of pulmonary rehabilitation may be useful for patients with bronchiectasis, no confirming studies have been performed to date, and additional research in this area is warranted.

  13. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were ...

  14. Disease investigations : Study of waterfowl botulism

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Studies were done to determine the ecology of the botulism organism Clostridium botulinum Type C and the manner of which toxin is ingested by the waterfowl so that...

  15. Experimental investigation of the effect of titanium dioxide and barium titanate additives on DC transient currents in low density polyethylene

    DEFF Research Database (Denmark)

    Khalil, M.S; Henk, Peter O; Henriksen, Mogens

    1988-01-01

    The effect of titanium dioxide as a semiconductive additive and barium titanate as a highly polar additive on the DC transient currents in low-density polyethylene is investigated. Experiments were made using thick specimens under a high electric field (>25×106 V/m) and a constant temperature of 40...

  16. Water Sensitive Urban Design: An Investigation of Current Systems, Implementation Drivers, Community Perceptions and Potential to Supplement Urban Water Services

    Directory of Open Access Journals (Sweden)

    Ashok K. Sharma

    2016-06-01

    Full Text Available Large scale centralised water, wastewater and stormwater systems have been implemented for over 100 years. These systems have provided a safe drinking water supply, efficient collection and disposal of wastewater to protect human health, and the mitigation of urban flood risk. The sustainability of current urban water systems is under pressure from a range of challenges which include: rapid population growth and resulting urbanisation, climate change impacts, and infrastructure that is ageing and reaching capacity constraints. To address these issues, urban water services are now being implemented with Integrated Urban Water Management (IUWM and Water Sensitive Urban Design (WSUD approaches. WSUD systems can deliver multiple benefits including water conservation, stormwater quality improvement, flood control, landscape amenity and a healthy living environment. These systems can be provided as stand-alone systems or in combination with centralised systems. These systems are still novel and thus face knowledge gaps that are impeding their mainstream uptake. Knowledge gaps cover technical, economic, social, and institutional aspects of their implementation. This paper is based on the outcomes of a comprehensive study conducted in South Australia which investigated impediments for mainstream uptake of WSUD, community perceptions of WSUD and potential of WSUD to achieve water conservation through the application of alternative resources, and in flood management. The outcomes are discussed in this paper for the benefit of water professionals engaged with WSUD planning, implementation, community consultation and regulation. Although the paper is based on a study conducted in South Australia, the comprehensive framework developed to conduct this detailed study and investigation can be adopted in any part of the world.

  17. Investigating Adaptive Grieving Styles: A Delphi Study

    Science.gov (United States)

    Doughty, Elizabeth A.

    2009-01-01

    There has been an evolution in the understanding of the nature of grief since S. Freud's initial work, Mourning and Melancholia (1917/1953). Mental health practitioners and researchers have established new models to aid in the conceptualization and treatment of grief issues. The purpose of this study was to examine the opinions of experts in the…

  18. Investigating Adaptive Grieving Styles: A Delphi Study

    Science.gov (United States)

    Doughty, Elizabeth A.

    2009-01-01

    There has been an evolution in the understanding of the nature of grief since S. Freud's initial work, Mourning and Melancholia (1917/1953). Mental health practitioners and researchers have established new models to aid in the conceptualization and treatment of grief issues. The purpose of this study was to examine the opinions of experts in the…

  19. Spoofing Faces Using Makeup: An Investigative Study

    OpenAIRE

    Chen, Cunjian; Dantcheva, Antitza; Swearingen, Thomas; Ross, Arun

    2017-01-01

    International audience; Makeup can be used to alter the facial appearance of a person. Previous studies have established the potential of using makeup to obfuscate the identity of an individual with respect to an automated face matcher. In this work, we analyze the potential of using makeup for spoofing an identity, where an individual attempts to impersonate another per-son's facial appearance. In this regard, we first assemble a set of face images downloaded from the internet where individu...

  20. CURRENT STUDY ON THE FUNDING SOURCES COVERAGE OF CURRENT ASSETS TO COMPANIES LISTED ON THE BUCHAREST STOCK EXCHANGE

    Directory of Open Access Journals (Sweden)

    Teodor HADA

    2014-06-01

    Full Text Available This paper presents issues about the coverage with financing sources of current assets for 64 companies listed on the Bucharest Stock Exchange. The aim of the study is to see how to calculate indicators specific to current assets and the general framework offered as whole analysis of the financing sources of current assets. The introduction of the paper presents the objective, the research methodology and the novelties brought by this study. Further on, this study shows the various views of the authors about the concept of "current assets", financing sources of current assets, the calculation of net working capital, setting the limits of the normal working capital and determining the speed of rotation. After that was done, based on the theory, a case study was performed, for companies covered in this study. Conclusions focused on determining the final data about what was detailed in the previous paragraphs.

  1. Investigation on the Arc Ignition Characteristics and Energy Absorption of Liquid Metal Current Limiter Based on Self-Pinch Effect

    Institute of Scientific and Technical Information of China (English)

    JU Xingbao; SUN Haishun; YANG Zhuo; ZHANG Junmin

    2016-01-01

    The GaInSn liquid metal current limiter based on the fluid pinch effect has broad application prospects due to its particular properties.However,the limited rated current and ability of power dissipation are the critical problems for its wide application.Firstly,the temperature distribution of the liquid metal current limiter (LMCL) was obtained by experiments with a rated current of 1 kA and the arc ignition phenomenon was observed with 1.5 kA,which indicates that the rated current is mainly limited by the arc rather than the high temperature compared to the traditional switchgears.Furthermore,an improved method is proposed by adding the paralleled pure resistance,impedance or another LMCL element to protect the setup from the fault energy concentration in the setup.The problem of a slower arc voltage increasing rate can be solved by adding a paralleled impedance with suitable parameters.Finally,the current limiting properties based on the improved method were investigated and the alternating oscillating current was found between two paralleled LMCL elements owing to their deviation of arc ignition in reality.

  2. 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

  3. An Investigation of Current and Future Data Systems in Numerical Meteorology

    Science.gov (United States)

    Diak, George R.; Burns, Barbara A.; Wu, Xiangqian

    1996-01-01

    The Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sounder (MHS) constitute the advanced microwave sounding system to be flown on the EOS-PM platform. Similar instruments (the AMSU-A corresponding to the AMSU and the AMSU-B corresponding to the MHS) are scheduled to become operational on the NOAA polar orbiting satellites beginning with NOAA-K. The unique characteristics of the AMSU-MHS instruments, as compared to the capabilities of their infrared and microwave predecessors, introduce new opportunities, and challenges, for operational retrievals of atmospheric structure. Not only will these new data improve present capabilities for the retrieval of atmospheric profiles of temperature and moisture, but they will provide the only opportunity for successfully retrieving atmospheric temperature and humidity profiles in the presence of modest amounts of cloud and precipitation. A complementary opportunity is presented by the potential of the AMSU-MHS to obtain information about the structure of clouds and precipitation. The data sets obtained will contribute to the current knowledge of global water and energy budgets, and provide critical information on the horizontal and vertical distribution of tropospheric water vapor, the spatial and temporal distribution of rain, and the relationship of cloud formation and dissipation to atmospheric dynamics and thermodynamics.

  4. Optical timing studies of isolated neutron stars: Current Status

    CERN Document Server

    Mignani, R P

    2010-01-01

    Being fast rotating objects, Isolated Neutron Stars (INSs) are natural targets for high-time resolution observations across the whole electromagnetic spectrum. With the number of objects detected at optical (plus ultraviolet and infrared) wavelengths now increased to 24, high-time resolution observations of INSs at these wavelengths are becoming more and more important. While classical rotation-powered radio pulsars, like the Crab and Vela pulsars, have been the first INSs studied at high-time resolution in the optical domain, observations performed in the last two decades have unveiled potential targets in other types of INSs which are not rotation powered, although their periodic variability is still related to the neutron star rotation. In this paper I review the current status of high-time resolution observations of INSs in the optical domain for different classes of objects: rotation-powered pulsars, magnetars, thermally emitting neutron stars, and rapid radio transients, I describe their timing properti...

  5. An Experimental Investigation of Passive Variable-Pitch Vertical-Axis Ocean Current Turbine

    Directory of Open Access Journals (Sweden)

    Ridho Hantoro

    2011-04-01

    Full Text Available Vertical-axis hydrokinetic turbines with fixed pitch blades typically suffer from poor starting torque, low efficiency and shaking due to large fluctuations in both radial and tangential force with azimuth angle. Maximizing the turbine power output can be achieved only if the mechanism of generation of the hydrodynamic force on the blades is clearly identified and tools to design high-performance rotors are developed. This paper describes an initial experimental investigation to understand more of the performance on vertical-axis turbine related to the effect of fixed-pitch and passive variable-pitch application using airfoil NACA 0018. Comparative analysis according to aspects of rotation and tip speed ratios was discussed. Information regarding the changes of foil position in passive variable-pitch during rotation at a limited range of flow velocity variations test was obtained and analyzed.

  6. The Europa Imaging System (EIS): Investigating Europa's geology, ice shell, and current activity

    Science.gov (United States)

    Turtle, Elizabeth; Thomas, Nicolas; Fletcher, Leigh; Hayes, Alexander; Ernst, Carolyn; Collins, Geoffrey; Hansen, Candice; Kirk, Randolph L.; Nimmo, Francis; McEwen, Alfred; Hurford, Terry; Barr Mlinar, Amy; Quick, Lynnae; Patterson, Wes; Soderblom, Jason

    2016-07-01

    NASA's Europa Mission, planned for launch in 2022, will perform more than 40 flybys of Europa with altitudes at closest approach as low as 25 km. The instrument payload includes the Europa Imaging System (EIS), a camera suite designed to transform our understanding of Europa through global decameter-scale coverage, topographic and color mapping, and unprecedented sub- meter-scale imaging. EIS combines narrow-angle and wide-angle cameras to address these science goals: • Constrain the formation processes of surface features by characterizing endogenic geologic structures, surface units, global cross-cutting relationships, and relationships to Europa's subsurface structure and potential near-surface water. • Search for evidence of recent or current activity, including potential plumes. • Characterize the ice shell by constraining its thickness and correlating surface features with subsurface structures detected by ice penetrating radar. • Characterize scientifically compelling landing sites and hazards by determining the nature of the surface at scales relevant to a potential lander. EIS Narrow-angle Camera (NAC): The NAC, with a 2.3°° x 1.2°° field of view (FOV) and a 10-μμrad instantaneous FOV (IFOV), achieves 0.5-m pixel scale over a 2-km-wide swath from 50-km altitude. A 2-axis gimbal enables independent targeting, allowing very high-resolution stereo imaging to generate digital topographic models (DTMs) with 4-m spatial scale and 0.5-m vertical precision over the 2-km swath from 50-km altitude. The gimbal also makes near-global (>95%) mapping of Europa possible at ≤50-m pixel scale, as well as regional stereo imaging. The NAC will also perform high-phase-angle observations to search for potential plumes. EIS Wide-angle Camera (WAC): The WAC has a 48°° x 24°° FOV, with a 218-μμrad IFOV, and is designed to acquire pushbroom stereo swaths along flyby ground-tracks. From an altitude of 50 km, the WAC achieves 11-m pixel scale over a 44-km

  7. Current and future molecular approaches to investigate the white pine blister rust pathosystem

    Science.gov (United States)

    B. A. Richardson; A. K. M. Ekramoddoulah; J.-J. Liu; M.-S. Kim; N. B. Klopfenstein

    2010-01-01

    Molecular genetics is proving to be especially useful for addressing a wide variety of research and management questions on the white pine blister rust pathosystem. White pine blister rust, caused by Cronartium ribicola, is an ideal model for studying biogeography, genetics, and evolution because: (1) it involves an introduced pathogen; (2) it includes multiple primary...

  8. How Do Clinicians Learn About Knowledge Translation? An Investigation of Current Web-Based Learning Opportunities

    OpenAIRE

    Damarell, Raechel A; Tieman, Jennifer J

    2017-01-01

    Background Clinicians are important stakeholders in the translation of well-designed research evidence into clinical practice for optimal patient care. However, the application of knowledge translation (KT) theories and processes may present conceptual and practical challenges for clinicians. Online learning platforms are an effective means of delivering KT education, providing an interactive, time-efficient, and affordable alternative to face-to-face education programs. Objective This study ...

  9. Experimental Investigation of an Automobile Air-Conditioning System using Integrated Brushless Direct Current Motor Rotary Compressor

    Directory of Open Access Journals (Sweden)

    Sukri M.F.

    2016-01-01

    Full Text Available The present study presents an experimental investigation on the effect of condenser air inlet temperature and dimensionless parameter of X on the performance of automobile air-conditioning (AAC system using integrated brushless direct current motor-rotary compressor and electronic expansion valve. The other components of AAC system are from original component of AAC system used for medium size passenger car. The experimental results showed that the increment of the condenser air inlet temperature and X caused an increase in condensing temperature, cooling capacity and compressor work, while decreasing the coefficient of performance (COP. Meanwhile, the evaporating temperature increase with the increment of condenser air inlet temperature, but decrease with decrement of X. In general, AAC system have to work at higher value of X in order to produce more cooling capacity, thereby increment in compressor work also occurs due to energy balance. However, at higher value of X, the COP of the system dropped due to dominant increase in compressor power, as opposed to a rise in cooling capacity. Due to this reason, the best operation of this compressor occurs at X = 4.96 for constant T5 (35ºC, or at T5 = 30ºC for constant X (4.96.

  10. Study of toroidal current penetration during current ramp in JIPP T-IIU with fast response Zeeman polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, H.; Hiraki, N. [Kyushu Inst. of Tech., Kitakyushu, Fukuoka (Japan); Toi, K. [and others

    1997-01-01

    The toroidal current penetration is studied in current ramp experiments of the JIPP T-IIU tokamak. The poloidal magnetic field profile in the peripheral region of a plasma (0.5 {<=} {rho} {<=} 1.0) has been measured directly with a newly developed fast response Zeeman polarimeter. The experimental results indicate that an obvious skin effect of toroidal current density is clearly observed during both the current ramp-up and ramp-down experiments. The experimentally obtained toroidal current density profiles are well described by the profiles calculated on the assumption of the neoclassical electrical conductivity. Quasi-linear {Delta}`-analysis of tearing modes for the measured current density profile is consistent with time behaviour of coherent MHD modes such as m=4/n=1 or m=3/n=1 (m: poloidal mode number, n: toroidal mode number) often observed during the current ramp-up phase. The effect of these MHD modes on current penetration during the current ramp-up discharges is studied. (author)

  11. Current state of the hydrothermal geochemistry studies at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Fausto L, J.J.; Jimenez S, M.E.; Esquer P, I.

    1981-01-01

    The current state of hydrothermal geochemistry studies being carried out at the field are reported. These studies are based on the results of chemical analysis of water samples collected during 1979 and 1980 at the geothermal wells of the area known as Cerro Prieto I, as well as from those located in the Cerro Prieto II and Cerro Prieto III areas, some of which have only recently started flowing. Data are presented on the chemical variations of the main chemical constituents dissolved in the waters, as well as on the Na/K and Na-K-Ca chemical relations and the temperatures calculated from them and from SiO/sub 2/. Fluid recharge into the reservoir and its direction of flow are interpreted from isotherm contour maps of the field prepared from Na/K and Na-K-Ca geothermometry and from concentration contour maps of some of the main chemical constituents. Well M-43 is discussed as an example of a well affected by well completion problems in its production casing. Its behavior is explained on the basis of the chemical characteristics of the produced water. The chemical changes that have taken place in some of the wells during production are explained by correlating the chemistry with the production mechanisms of the well (steam-water production rates).

  12. Current Advances in the Metabolomics Study on Lotus Seeds.

    Science.gov (United States)

    Zhu, Mingzhi; Liu, Ting; Guo, Mingquan

    2016-01-01

    Lotus (Nelumbo nucifera), which is distributed widely throughout Asia, Australia and North America, is an aquatic perennial that has been cultivated for over 2,000 years. It is very stimulating that almost all parts of lotus have been consumed as vegetable as well as food, especially the seeds. Except for the nutritive values of lotus, there has been increasing interest in its potential as functional food due to its rich secondary metabolites, such as flavonoids and alkaloids. Not only have these metabolites greatly contributed to the biological process of lotus seeds, but also have been reported to possess multiple health-promoting effects, including antioxidant, anti-amnesic, anti-inflammatory, and anti-tumor activities. Thus, comprehensive metabolomic profiling of these metabolites is of key importance to help understand their biological activities, and other chemical biology features. In this context, this review will provide an update on the current technological platforms, and workflow associated with metabolomic studies on lotus seeds, as well as insights into the application of metabolomics for the improvement of food safety and quality, assisting breeding, and promotion of the study of metabolism and pharmacokinetics of lotus seeds; meanwhile it will also help explore new perspectives and outline future challenges in this fast-growing research subject.

  13. Solar cycle in current reanalyses: (nonlinear attribution study

    Directory of Open Access Journals (Sweden)

    A. Kuchar

    2014-12-01

    Full Text Available This study focusses on the variability of temperature, ozone and circulation characteristics in the stratosphere and lower mesosphere with regard to the influence of the 11 year solar cycle. It is based on attribution analysis using multiple nonlinear techniques (Support Vector Regression, Neural Networks besides the traditional linear approach. The analysis was applied to several current reanalysis datasets for the 1979–2013 period, including MERRA, ERA-Interim and JRA-55, with the aim to compare how this type of data resolves especially the double-peaked solar response in temperature and ozone variables and the consequent changes induced by these anomalies. Equatorial temperature signals in the lower and upper stratosphere were found to be sufficiently robust and in qualitative agreement with previous observational studies. The analysis also pointed to the solar signal in the ozone datasets (i.e. MERRA and ERA-Interim not being consistent with the observed double-peaked ozone anomaly extracted from satellite measurements. Consequently the results obtained by linear regression were confirmed by the nonlinear approach through all datasets, suggesting that linear regression is a relevant tool to sufficiently resolve the solar signal in the middle atmosphere. Furthermore, the seasonal dependence of the solar response was also discussed, mainly as a source of dynamical causalities in the wave propagation characteristics in the zonal wind and the induced meridional circulation in the winter hemispheres. The hypothetical mechanism of a weaker Brewer Dobson circulation was reviewed together with discussion of polar vortex stability.

  14. Solar cycle in current reanalyses: (non)linear attribution study

    Science.gov (United States)

    Kuchar, A.; Sacha, P.; Miksovsky, J.; Pisoft, P.

    2014-12-01

    This study focusses on the variability of temperature, ozone and circulation characteristics in the stratosphere and lower mesosphere with regard to the influence of the 11 year solar cycle. It is based on attribution analysis using multiple nonlinear techniques (Support Vector Regression, Neural Networks) besides the traditional linear approach. The analysis was applied to several current reanalysis datasets for the 1979-2013 period, including MERRA, ERA-Interim and JRA-55, with the aim to compare how this type of data resolves especially the double-peaked solar response in temperature and ozone variables and the consequent changes induced by these anomalies. Equatorial temperature signals in the lower and upper stratosphere were found to be sufficiently robust and in qualitative agreement with previous observational studies. The analysis also pointed to the solar signal in the ozone datasets (i.e. MERRA and ERA-Interim) not being consistent with the observed double-peaked ozone anomaly extracted from satellite measurements. Consequently the results obtained by linear regression were confirmed by the nonlinear approach through all datasets, suggesting that linear regression is a relevant tool to sufficiently resolve the solar signal in the middle atmosphere. Furthermore, the seasonal dependence of the solar response was also discussed, mainly as a source of dynamical causalities in the wave propagation characteristics in the zonal wind and the induced meridional circulation in the winter hemispheres. The hypothetical mechanism of a weaker Brewer Dobson circulation was reviewed together with discussion of polar vortex stability.

  15. The issues of current rainfall estimation techniques in mountain natural multi-hazard investigation

    Science.gov (United States)

    Zhuo, Lu; Han, Dawei; Chen, Ningsheng; Wang, Tao

    2017-04-01

    Mountain hazards (e.g., landslides, debris flows, and floods) induced by rainfall are complex phenomena that require good knowledge of rainfall representation at different spatiotemporal scales. This study reveals rainfall estimation from gauges is rather unrepresentative over a large spatial area in mountain regions. As a result, the conventional practice of adopting the triggering threshold for hazard early warning purposes is insufficient. The main reason is because of the huge orographic influence on rainfall distribution. Modern rainfall estimation methods such as numerical weather prediction modelling and remote sensing utilising radar from the space or on land are able to provide spatially more representative rainfall information in mountain areas. But unlike rain gauges, they only indirectly provide rainfall measurements. Remote sensing suffers from many sources of errors such as weather conditions, attenuation and sampling methods, while numerical weather prediction models suffer from spatiotemporal and amplitude errors depending on the model physics, dynamics, and model configuration. A case study based on Sichuan, China is used to illustrate the significant difference among the three aforementioned rainfall estimation methods. We argue none of those methods can be relied on individually, and the challenge is on how to make the full utilisation of the three methods conjunctively because each of them only provides partial information. We propose that a data fusion approach should be adopted based on the Bayesian inference method. However such an approach requires the uncertainty information from all those estimation techniques which still need extensive research. We hope this study will raise the awareness of this important issue and highlight the knowledge gap that should be filled in so that such a challenging problem could be tackled collectively by the community.

  16. A EUropean study on effectiveness and sustainability of current Cardiac Rehabilitation programmes in the Elderly

    DEFF Research Database (Denmark)

    Prescott, Eva; Meindersma, Esther P; van der Velde, Astrid E

    2016-01-01

    on effectiveness and sustainability of current cardiac rehabilitation programmes in the elderly (EU-CaRE) project consists of an observational study and an open prospective, investigator-initiated multicentre randomised controlled trial (RCT) involving mobile telemonitoring guided CR (mCR). OBJECTIVE: The aim...... of EU-CaRE is to map the efficiency of current CR of the elderly in Europe, and to investigate whether mCR is an effective alternative in terms of efficacy, adherence and sustainability. METHODS AND RESULTS: The EU-CaRE study includes patients aged 65 years or older with ischaemic heart disease or who...... home-based programme while the control group will receive no advice or coaching throughout the study period. Outcomes will be assessed after the end of CR and at 12 months follow-up. The primary outcome is VO2peak and secondary outcomes include variables describing CR uptake, adherence, efficacy...

  17. INVESTIGATION OF HIGH-CURRENT INTERRUPTING CONTACTS WORKING SURFACES MECHANICAL INTERACTION NATURE

    Directory of Open Access Journals (Sweden)

    O.G. Volkova

    2016-03-01

    Full Text Available Introduction. The nature of the interaction of high-working surfaces of the electrical contact uniquely affects their performance. By the failure of the contacts in the main drive processes resulting from complex destructive factors affecting their performance. However, not all processes are studied in detail and give in modeling. The purpose of the paper is to show the possibility of using the method of holographic interferometry to estimate the plastic deformation in the zone of contact interaction. One of the significant factors affecting the work of the contact pair is the compressive force of the contact surfaces. Compression discontinuous contact is directly connected with the processes of elastic and plastic deformation of the contact material, which is particularly evident in the contact details of the powder or composite materials. The paper focuses on the plastic deformation of the surface layers of discontinuous contact in circuit, it is believed that it is directly related to the mechanism of conductivity of contacts. As shown, a significant effect on the deformation of the contact surfaces and renders the working environment, in particular transformer oil. Methodology. Assessing the impact of compression forces on the deformation of the contact surface was conducted experimentally using the method of holographic interferometry. Results. Experimental studies, which indicated that the compact and powder materials plastic deformation in and around the area microcontacts simplistically stated that requires experimental verification. A method for evaluating the state of stress, which affects the formation and destruction of the local contact spots. Practical value. Using the experimental method of determining the movement of the contact region allows you to optimize discontinuous contacts from composite and powder materials.

  18. Particle Image Velocimetry Study of Density Current Fronts

    Science.gov (United States)

    Martin, Juan Ezequiel

    2009-01-01

    Gravity currents are flows that occur when a horizontal density difference causes fluid to move under the action of gravity; density currents are a particular case, for which the scalar causing the density difference is conserved. Flows with a strong effect of the horizontal density difference, even if only partially driven by it--such as the…

  19. Experimental investigations of electric current under transverse and longitudinal electric field in uniaxially deformed p-Ge

    Science.gov (United States)

    Abramov, A. A.; Akimov, V. I.; Dalakyan, A. T.; Tulupenko, Victor N.; Zaitsev, A. M.; Danilov, S. N.; Firsov, D. A.; Shalygin, V. A.

    1999-11-01

    Comparison between cases of longitudinal and transverse directions of uniaxial pressure and strong electric field, affected the bulk hole germanium, to use it for lasting in far IR region has been carried out. Conclusion about preference of crossed directions is made. Threshold pressure, at which stimulated radiation arises, independence of crystallographic direction, along which external influences are applied, is also discussed. The results of experimental investigations of the crossed directions of uniaxial pressure and electric current are given.

  20. The investigation of heterogeneous flow generated by the direct current plasma torch

    Science.gov (United States)

    Evmenchikov, N. L.; Penyazkov, O. G.; Shatan, I. N.

    2016-11-01

    In the article, the two-phase flow of electric arc gas heater of the linear scheme is studied. The power of the plasma torch can be varied from 200 to 1500 kW. For stabilization of the electric arc a magnetic coil is used. The operation of the plasma torch took place at overpressure in the discharge chamber. Injection of the powder was made near the exit of the nozzle. A powder of SiO2 was used as a disperse phase. The size of the particles was not more than 50 microns. The dispensing device was used for the powder injection. The technique of velocity measurement in high-temperature heterogeneous flow from the registration of flow by the high-speed camera is presented. The results of measurements indicate that the speed of the particles much lower than the speed of the gas. The results of measuring the heat flux along the axis of the plasma torch are presented. The heat flux was measured by means of regular mode uncooled sensors with tablet type calorimeters.

  1. CURRENT APPLIED INVESTIGATIONS OF THE DEPARTMENT OF HIGHER MATHEMATICS OF MGSU

    Directory of Open Access Journals (Sweden)

    Bobyleva Tat’yana Nikolaevna

    2015-12-01

    Full Text Available The article presents an overview of some research works done by the academic staff of the Department in the field of differential equations, solid mechanics, probability theory and mathematical statistics, theory of functions of real and complex variable, functional analysis, topology, the theory of polymer composites having theoretical and practical interest, which leads to wide possibilities of application of these researches for formulation and solution of model problems of construction, technology and economics. In particular, we considered the problem of planar non-rotational fluid flow with a free boundary, discrete kinetic model of rarefied gas, the Burgers-Huxley equation of advection-diffusion fractional order. We studied the stress concentrators due to the geometry of the boundary and coupling elements made of materials with different physical properties, stress relaxation in concrete, free vibrations of isotropic hollow balls. The issues of loaded systems’ research arise frequently in practice in the problems with lumped loads. Extremum problems were considered, in particular, in the loaded space of Jacobi, extremum problems for analytic functions of some classes, the use of the duality of linear spaces applied to extremum problems of complex analysis. The researches on methods of teaching mathematics in technical universities were performed.

  2. A Literature Investigation about Electrospinning and Nanofibers: Historical Trends, Current Status and Future Challenges.

    Science.gov (United States)

    Nascimento, Marcio L F; Araújo, Evando S; Cordeiro, Erlon R; de Oliveira, Ariadne H P; de Oliveira, Helinando P

    2015-01-01

    The development of new fibrilar materials based on electrospinning (ES) technique has a notable history of nearly four centuries of discoveries and results. The eletrospinning manufacturing is one of the most widely reported methods for nanofiber (NF) manufacturing, providing security, high quality and productivity. In spite of the first patent about electrospinning has been applied in April 5(th), 1900 by John Francis Cooley, a historical perspective (since 1600s) about this amazing discovery represents an important step for future applications. Nanofibers have been considered one of the top interesting fundamental study objects for academicians, and greatest intriguing business materials for modern industry. As a consequence, lucrative organizations and companies have explored the relevance of nanofibers. In this paper, the quantity of published manuscripts and patent inventions is presented and the correlation of research activities to the production of new electrospinning materials is shown. China and the United States have been leading in electrospinning and nanofibers development. The company triumph is mostly dependent on applications improvement relevant for broader business society. A dramatic rise of interest in nanofibers produced by electrospinning technique has been confirmed due to the publication data, author's affiliation, keywords, and essential characterization procedures. Is has been shown that the number of publications on electrospinning and nanofibers researches from academic institutions is higher than industrial laboratories. More than 1,891 patents using the term "electrospinning" and 2,960 with the term "nanofibers" according to the European Patent Office at title or abstract have been filed around the world up to 2013. These numbers just continue to increase along with worldwide ES-related sales. Curiously, for the same period 11,973 electrospinning documents and 18,679 nanofibers-related (mainly manuscripts) were published considering

  3. Investigating Relationships among Pre-Service Science Teachers' Conceptual Knowledge of Electric Current, Motivational Beliefs and Self-Regulation

    Science.gov (United States)

    Inaltun, Hüseyin; Ates, Salih

    2015-01-01

    The purpose of this study is to examine relationships among pre-service science teachers' conceptual knowledge of electric current, motivational beliefs, and self-regulation. One hundred and twenty-seven students (female = 107, male = 20) enrolled in the science education program of a public university in Ankara participated the study. A concept…

  4. Investigating Relationships among Pre-Service Science Teachers' Conceptual Knowledge of Electric Current, Motivational Beliefs and Self-Regulation

    Science.gov (United States)

    Inaltun, Hüseyin; Ates, Salih

    2015-01-01

    The purpose of this study is to examine relationships among pre-service science teachers' conceptual knowledge of electric current, motivational beliefs, and self-regulation. One hundred and twenty-seven students (female = 107, male = 20) enrolled in the science education program of a public university in Ankara participated the study. A concept…

  5. MODEL STUDY OF THE DOUBLE FED MACHINE WITH CURRENT CONTROL

    Directory of Open Access Journals (Sweden)

    A. S. Lyapin

    2016-07-01

    Full Text Available The paper deals with modeling results of the double fed induction machine with current control in the rotor circuit. We show the most promising applications of electric drives on the basis of the double fed induction machine and their advantages. We present and consider functional scheme of the electric drive on the basis of the double fed induction machine with current control. Equations are obtained for creation of such machine mathematical model. Expressions for vector projections of rotor current are given. According to the obtained results, the change of the vector projections of rotor current ensures operation of the double fed induction machine with the specified values of active and reactive stator power throughout the variation range of sliding motion. We consider static characteristics of double fed machine with current control. Energy processes proceeding in the machine are analyzed. We confirm the operationpossibility of double fed induction machine with current controlin the rotor circuit with given values of active and reactive stator power. The presented results can be used for creation of mathematical models and static characteristics of double fed machines with current control of various capacities.

  6. Study of wavelet transform type high-current transformer

    Institute of Scientific and Technical Information of China (English)

    卢文科; 朱长纯; 刘君华; 张建军

    2002-01-01

    The wavelet transformation is applied to the high-current transformer.The high-current transformer elaborated in the paper is mainly applied to the measurement of AC/DC high-current.The principle of the transformer is the Hall direct-measurement principle.The transformer has the following three characteristics:firstly, the effect of the remnant field of the iron core on the measurement is decreased;secondly,because the temperature compensation is adopted,the transformer has good temperature charactreristic;thirdly,be-cause the wavelet transfomation technology is adopted,the transformer has the capacity of good antijanming.

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

    Science.gov (United States)

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

    2006-01-01

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

  8. Coupled Numerical Study of Turbidity Currents, Internal Hydraulic Jump and Morphological Signatures

    Science.gov (United States)

    Hu, P.; Cao, Z.; He, Z.; Gareth, P.

    2013-12-01

    Abstract: The last two decades have seen intensive experimental and numerical studies of the occurrence condition of internal hydraulic jump in turbidity currents and the induced morphological signatures (Garcia and Parker 1989; Kostic and Parker 2006). Yet there are two critical issues that remain insufficiently or inappropriately addressed. First, depositional turbidity currents are imposed on steep slopes in both flume experiments and numerical cases, exclusively based on a configuration consisting of an upstream sloping portion and a downstream horizontal portion linked by a slope break. This appears physically counterintuitive as steep slope should favour self-accelerating erosional turbidity currents (Parker et al. 1986). The second issue concerns the numerical studies. There exist significant interactions among the current, sediment transport and bed topography. Due to the slope break in bed, the current may experience an internal hydraulic jump, leaving morphological signatures on the bed, which in turn affects the current evolution. Nevertheless, simplified decoupled models are exclusively employed in previous numerical investigations, in which the interactions are either partly or completely ignored without sufficient justification. The present paper aims to address the above-mentioned two issues relevant to the occurrence condition of the internal hydraulic jump and the induced morphological signatures. A recently developed well-balanced coupled numerical model for turbidity currents (Hu et al. 2012) is applied. In contrast to previous studies, erosional turbidity currents will be imposed at the upstream boundary, which is much more typical of the field. The effects of sediment size, bed slope decrease, and upstream and downstream boundary conditions are revealed in detail. In addition, the evolution of turbidity currents over a bed characterized by gradual decrease in slope is also discussed. References Garcia, M. H., and Parker, G. (1989). Experiments

  9. Study on UPF Harmonic Current Detection Method Based on DSP

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H J [Northwestern Polytechnical University, Xi' an 710072 (China); Pang, Y F [Xi' an University of Technology, Xi' an 710048 (China); Qiu, Z M [Xi' an University of Technology, Xi' an 710048 (China); Chen, M [Northwestern Polytechnical University, Xi' an 710072 (China)

    2006-10-15

    Unity power factor (UPF) harmonic current detection method applied to active power filter (APF) is presented in this paper. The intention of this method is to make nonlinear loads and active power filter in parallel to be an equivalent resistance. So after compensation, source current is sinusoidal, and has the same shape of source voltage. Meanwhile, there is no harmonic in source current, and the power factor becomes one. The mathematic model of proposed method and the optimum project for equivalent low pass filter in measurement are presented. Finally, the proposed detection method applied to a shunt active power filter experimental prototype based on DSP TMS320F2812 is developed. Simulation and experiment results indicate the method is simple and easy to implement, and can obtain the real-time calculation of harmonic current exactly.

  10. Durability Study of SOFCs Under Cycling Current Load Conditions

    DEFF Research Database (Denmark)

    Hagen, Anke; Hendriksen, Peter Vang; Frandsen, Henrik Lund;

    2009-01-01

    In fuel cell applications, the cells must be able to withstand varying operating conditions. Anode supported solid oxide fuel cells were tested under cycling current load in order to determine the durability and possibly identify degradation mechanisms. At 750 °C and a cycling between zero and 0.......75 A cm-2, the cell voltage degradation rate was similar to tests with the corresponding high constant current density. However, by analyzing the impedance spectra it was found that anode degradation was becoming more important when going from constant to cycling conditions. Running the cycling load tests...... at 850 °C, the cells degraded similarly as under the corresponding constant current load whereas, in some cases, cells failed mechanically after a few hundred hours. These cells did not experience severe additional degradation due to the cycling of the current density until the point of failure...

  11. The end of universality: new collectivities in current literary studies

    Directory of Open Access Journals (Sweden)

    Ronald Greene

    2015-11-01

    Full Text Available The author investigates how the literary studies reacted to the conceptual crises of universalism, especially after WWII. In order to replace a concept that refers to the ability of a literary work to transcend time and space, literary studies should focus on different and specific collectivities that, situated in time and space, read and interpret literary works. The author makes use of the concept of the obverse, in which two poems, from different historical moments and intellectual traditions are compared based on a common social-historical problem they are trying to solve.    O autor investiga sobre como os estudos literários reagiram à crise do conceito de universalismo, sobretudo depois da II Guerra Mundial. Para substituir um conceito que se refere à capacidade de uma obra literária transcender tempo e espaço, os estudos literários deveriam indagar sobre as diferentes coletividades específicas, no tempo e no espaço, que leem e dão significado à obra literária. Para isso, o autor se utiliza do conceito de “obverso”, em que dois poemas, de épocas e tradições intelectuais diferentes, são comparados a partir de um problema sócio-histórico que tentam resolver.      This work is licensed under a Creative Commons Attribution 3.0 License.

  12. Study of lower hybrid current drive for the demonstration reactor

    Energy Technology Data Exchange (ETDEWEB)

    Molavi-Choobini, Ali Asghar [Dept. of Physics, Faculty of Engineering, Islamic Azad University, Shahr-e-kord Branch, Shahr-e-kord (Iran, Islamic Republic of); Naghidokht, Ahmed [Dept. of Physics, Urmia University, Urmia (Iran, Islamic Republic of); Karami, Zahra [Dept. of Engineering, Islamic Azad University, Zanjan Branch, Zanjan (Iran, Islamic Republic of)

    2016-06-15

    Steady-state operation of a fusion power plant requires external current drive to minimize the power requirements, and a high fraction of bootstrap current is required. One of the external sources for current drive is lower hybrid current drive, which has been widely applied in many tokamaks. Here, using lower hybrid simulation code, we calculate electron distribution function, electron currents and phase velocity changes for two options of demonstration reactor at the launched lower hybrid wave frequency 5 GHz. Two plasma scenarios pertaining to two different demonstration reactor options, known as pulsed (Option 1) and steady-state (Option 2) models, have been analyzed. We perceive that electron currents have major peaks near the edge of plasma for both options but with higher efficiency for Option 1, although we have access to wider, more peripheral regions for Option 2. Regarding the electron distribution function, major perturbations are at positive velocities for both options for flux surface 16 and at negative velocities for both options for flux surface 64.

  13. The Investigators' Brochure: a comparison of the draft international conference on harmonisation guideline with current Food and Drug Administration requirements.

    Science.gov (United States)

    Cocchetto, D M

    1995-12-01

    For several years, the United States Food and Drug Administration (FDA) has participated in a collaborative effort to harmonize the technical procedures for development and regulatory approval of human pharmaceuticals in multiple countries. This harmonization effort is the work of the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). At this point, ICH focuses on achieving harmonization of technical requirements in three major regions of the world, i.e., the United States, European Union, and Japan. One area for which harmonization is being sought is the format and content of the Investigators' Brochure. On October 27, 1993, the ICH Steering Committee agreed that the ICH draft guideline on the Investigators' Brochure should be made available for public comment. On August 9, 1994, the FDA published the draft guideline for the format and content of the Investigators' Brochure. This draft guideline was prepared by the Efficacy Expert Working Group of the ICH. FDA solicited written comments on this draft guideline until October 11, 1994. Ultimately, FDA intends to adopt the ICH Steering Committee's final guidelines on Investigators' Brochures as part of a larger document on good clinical practices. Therefore, the content of this draft guideline warrants careful attention. In this paper, ICH's proposed information for inclusion in the Investigators' Brochure is reviewed and compared with current regulatory requirements of FDA. The expanded contents of the Investigators' Brochure proposed by ICH, which represent potential new requirements beyond current FDA regulations, are highlighted. The major controversial elements of this draft guideline are summarized.

  14. Transcranial direct current stimulation in refractory continuous spikes and waves during slow sleep: a controlled study

    DEFF Research Database (Denmark)

    Varga, Edina T; Terney, Daniella; Atkins, Mary D;

    2011-01-01

    Cathodal transcranial direct current stimulation (tDCS) decreases cortical excitability. The purpose of the study was to investigate whether cathodal tDCS could interrupt the continuous epileptiform activity. Five patients with focal, refractory continuous spikes and waves during slow sleep were...... recruited. Cathodal tDCS and sham stimulation were applied to the epileptic focus, before sleep (1 mA; 20 min). Cathodal tDCS did not reduce the spike-index in any of the patients....

  15. Counseling psychology and psychotherapy skills’ studies: current status in Western and Russian Psychology

    Directory of Open Access Journals (Sweden)

    Kryuchkov K.S.

    2015-10-01

    Full Text Available The article presents a brief review of studies concerning the current status of the psychotherapeutic and counseling skills in the West (mainly in the USA and in Russia. Papers written by the fellows of the leading US labs in this field and by other scientists are reviewed in this article alongside with investigations of several Russian psychological institutions. We also introduce some theoretical and methodological papers of Russian scholars

  16. Investigating the current methods of assessing behavioral and psychological symptoms in residential aged care facilities in a metropolitan city.

    Science.gov (United States)

    Loi, Samantha M; Lautenschlager, Nicola T

    2017-05-01

    Up to 90% of people with dementia living in residential aged care facilities (RACFs) display behavioral and psychological symptoms of dementia (BPSD), and these are associated with poorer quality of life and increased morbidity and mortality. In order to implement appropriate interventions, it is important to understand the symptoms in more detail. Despite the availability of BPSD assessment tools, it is unknown what the current practice of monitoring of BPSD in RACFs. We sought to investigate the current BPSD assessment tools being used in RACFs and explore different stakeholders' views on current practices. A cross-sectional convenience sample of 21 clinicians were identified and administered a questionnaire. Old age psychiatrists, aged psychiatry clinicians, behavior management teams and RACF staff completed the questionnaires. Clinicians reported that objective consistent information about BPSD were important for recommending and implementing pharmacological and non-pharmacological strategies for BPSD; however, the use of validated BPSD assessments in RACFs was not a usual part of clinical practice. RACF staff stated the major barrier to assessment of BPSD was lack of time. Alternate methods of assessing BPSD which consider preferences from clinicians and RACF staff should be further investigated. Modern technology which can allow "real time" assessment may be a solution.

  17. Air Quality Study Using Satellites - Current Capability and Future Plans

    Science.gov (United States)

    Bhartia, Pawan K.; Joiner, Joanna; Gleason, James; Liu, Xiong; Torres, Omar; Krotkov, Nickolay; Ziemke, Jerry; Chandra, Sushil

    2008-01-01

    Satellite instruments have had great success in monitoring the stratospheric ozone and in understanding the processes that control its daily to decadal scale variations. This field is now reaching its zenith with a number of satellite instruments from the US, Europe and Canada capping several decades of active research in this field. The primary public policy imperative of this research was to make reliable prediction of increases in biologically active surface UV radiation due to human activity. By contrast retrieval from satellite data of atmospheric constituents and photo-chemically active radiation that affect air quality is a new and growing field that is presenting us with unique challenges in measurement and data interpretation. A key distinction compared to stratospheric sensors is the greatly enhanced role of clouds, aerosols, and surfaces (CAS) in determining the quality and quantity of useful data that is available for air quality research. In our presentation we will use data from several sensors that are currently flying on the A-train satellite constellation, including OMI, MODIS, CLOUDSAT, and CALIPSO, to highlight that CAS can have both positive and negative effects on the information content of satellite measurements. This is in sharp contrast to other fields of remote sensing where CAS are usually considered an interference except in those cases when they are the primary subject of study. Our analysis has revealed that in the reflected wavelengths one often sees much further down into the atmosphere, through most cirrus, than one does in the emitted wavelengths. The lower level clouds provide a nice background against which one can track long-range transport of trace gases and aerosols. In addition, differences in trace gas columns estimated over cloudy and adjacent clear pixels can be used to measure boundary layer trace gases. However, in order to take full advantage of these features it will be necessary to greatly advance our understanding of

  18. Investigation of Line Current Harmonics in Cascaded Multi-level Inverter Based Induction Motor Drive and an Adaptive On-line Selective Current Harmonic Elimination Algorithm

    Directory of Open Access Journals (Sweden)

    P. Avirajamanjula

    2015-03-01

    Full Text Available Multilevel Inverters (MLIs have drawn increasing attention in numerous applications, especially in drives, distributed energy resources area, utility etc. MLIs have the ability to synthesize a near sinusoidal output voltage wave with minimal Total Harmonic Distortion (THD in low frequency switching. Even though they offer lower THD, the presence of lower order harmonics is objectionable and harmonics elimination in Multilevel Inverters (MLIs has been receiving immense attention for the past few decades. Existing Selective Harmonic Elimination (SHE techniques can eliminate the objectionable lower order voltage harmonics with low switching frequency by solving the Fourier non-linear transcendental equations of the output voltage. The line current harmonics has a direct role to play on the magneto-motive force and results in increase of mismatching of air-gap permeance, vibrations, acoustic noise etc. This study proposes Normalized Least Mean Squares (NLMS algorithm based scheme to eliminate the selected dominant harmonics in load current using only the knowledge of the frequencies to be eliminated. The algorithm is simulated using MATLAB/SIMULINK tool for a three-phase VSI to eliminate the fifth and seventh harmonics. The informative simulation results verify the validity and effectiveness of the proposed algorithm. The system performance is analyzed based on the simulation results considering Total Harmonic Distortion (THD, magnitude of eliminated harmonics and frequency spectrum.

  19. Field Investigations of the July 2015 Pyroclastic Density Current Deposits of Volcán de Colima, Mexico

    Science.gov (United States)

    Atlas, Z. D.; Macorps, E.; Charbonnier, S. J.; Varley, N. R.

    2016-12-01

    Small-volume pyroclastic density currents (PDCs) occur relatively frequently and pose severe threats to surrounding populations and infrastructures at active explosive volcanoes. They are characterized by short duration and complex multiphase flow dynamics due to time and space variability in their properties, which include amongst others, particle concentration, granulometry, componentry, bulk rheology and velocity. Field investigations of the deposits emplaced by small-volume concentrated PDCs aim to improve our understanding of the transport and depositional processes of these flows: time and space variations in flow dynamics within a PDC moving downslope will reflect on the distribution, grainsize and component characteristics of its deposits. Our study focuses on the recent events of July 10th and 11th, 2015 at Volcán de Colima (Mexico) where the collapse of the recent lava dome complex and a portion of the southern crater rim led to the emplacement of successive pulses of small-volume concentrated PDCs on the southern flank, along the Montegrande and San Antonio ravines. A 3-dimensional field analysis of the PDCs' deposit architecture, total grain size distribution and component properties together with a geomorphic analysis of the affected ravines provide new insights on the lateral and vertical variations of flow dynamics for some of these small-volume concentrated PDCs. Preliminary results reveal three stratigraphic units with massive block, lapilli, ash facies within the valley confined and concentrated overbank deposits with increasing content in fines with distance from the summit, suggesting an increase in fragmentation processes within the PDCs. The middle unit is characterized by a finer grainsize, a higher accidental lithic content and a lower free crystal content. Moreover, direct correlations are found between rapid changes in channel morphology and generation of overbank (unconfined) flows that escaped valley confines, which could provide the

  20. [Current quality management situation and administration countermeasure study of enterprises marketing corneal contact lens].

    Science.gov (United States)

    Liu, Yungui; Yao, Ying; Shangguan, Shihao; Gu, Qun; Gao, Wuming; Chen, Yaoshui

    2014-05-01

    Study the current quality management situation of enterprises marketing corneal contact lens via systemic investigations and explore effective administration countermeasures in the future. The quality management indicators of sixty-two corneal contact lens marketing enterprises in Xuhui district of Shanghai were systematically investigated and enterprises of different operation models was compared and analyzed. Wholesale enterprises and retail chain enterprises are apparently better than independent enterprises almost in all facets. Facilitate market accession of corneal contact lens marketing enterprises, encourage the business model of retail chain, enhance supervision of corneal contact lens marketing enterprises, especially independent franchisors.

  1. Teaching and Learning English Functional Writing: Investigating Egyptian EFL Student Teachers' Currently-Needed Functional Writing Skills

    Science.gov (United States)

    Abdallah, Mahmoud M. S.

    2014-01-01

    At an age marked by the emergence of new literacies, vast technological developments, and social networking practices, language is currently approached from a pragmatic perspective that recognises its functional use to meet realistic communicative goals. Taking this into account, the present study sought to identify the functional writing skills…

  2. In situ transmission electron microscopy investigation of the structural changes in carbon nanotubes during electron emission at high currents

    Energy Technology Data Exchange (ETDEWEB)

    Doytcheva, Maya [Philips Research, Professor Holstlaan 4, 5656 AA Eindhovene (Netherlands); Kaiser, Monja [Philips Research, Professor Holstlaan 4, 5656 AA Eindhoven (Netherlands); Jonge, Niels de [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6030 (United States)

    2006-07-14

    The structural changes in carbon nanotubes under electron emission conditions were investigated in situ in a transmission electron microscope (TEM). The measurements were performed on individually mounted free-standing multi-walled carbon nanotubes (CNTs). It was found that the structure of the carbon nanotubes did not change gradually, as is the case with field emission electron sources made of sharp metal tips. Instead, changes occurred only above a current level of a few microamperes, which was different for each nanotube. Above the threshold current, carbon nanotubes underwent either structural damage, such as shortening and splitting of the apex of the nanotube, or closing of their open cap. The results are discussed on the basis of several models for degradation mechanisms.

  3. In situ Transmission Electron Microscopy Investigation of the Structural Changes in Carbon Nanotubes During Electron Emission at High Currents

    Energy Technology Data Exchange (ETDEWEB)

    Doytcheva, Maya [Philips Research, The Netherlands; Kaiser, Monja [Philips Research, The Netherlands; De Jonge, Niels [ORNL

    2006-01-01

    The structural changes in carbon nanotubes under electron emission conditions were investigated in situ in a transmission electron microscope (TEM). The measurements were performed on individually mounted free-standing multi-walled carbon nanotubes (CNTs). It was found that the structure of the carbon nanotubes did not change gradually, as is the case with field emission electron sources made of sharp metal tips. Instead, changes occurred only above a current level of a few microamperes, which was different for each nanotube. Above the threshold current, carbon nanotubes underwent either structural damage, such as shortening and splitting of the apex of the nanotube, or closing of their open cap. The results are discussed on the basis of several models for degradation mechanisms.

  4. Effects of alternating and direct electrical current application on the odontoblastic layer in human teeth : an in vitro study

    NARCIS (Netherlands)

    Alwas-Danowska, HM; Huysmans, MCDNJM; Verdonschot, EH

    1999-01-01

    Aim The aim of this study was to investigate the influence of a low intensity alternating current on the odontoblasts and odontoblast layer and compare this with the effects of a direct current. Methodology Teeth extracted for orthodontic were immersed in physiological saline stabilized with thymol

  5. Effects of alternating and direct electrical current application on the odontoblastic layer in human teeth : an in vitro study

    NARCIS (Netherlands)

    Alwas-Danowska, HM; Huysmans, MCDNJM; Verdonschot, EH

    1999-01-01

    Aim The aim of this study was to investigate the influence of a low intensity alternating current on the odontoblasts and odontoblast layer and compare this with the effects of a direct current. Methodology Teeth extracted for orthodontic were immersed in physiological saline stabilized with thymol

  6. Investigation of local tunneling current noise spectra on the silicon crystal surfaces by means of STM/STS

    Energy Technology Data Exchange (ETDEWEB)

    Mantsevich, V. N., E-mail: vmantsev@spmlab.phys.msu.su; Maslova, N. S. [Moscow State University, Department of Physics (Russian Federation); Cao, G. Y. [Chinese Academy of Sciences, Wuhan Institute of Physics and Mathematics (China)

    2015-08-15

    We report on a careful analysis of the local tunneling conductivity by means of ultra-high vacuum scanning tunneling microscopy/spectroscopy (STM/STS) technique in the vicinity of low-dimensional structures on the Si(111)–(7 × 7) and Si(110)–(16 × 2) surfaces. The power-law exponent α of low-frequency tunneling current noise spectra is investigated for different values of the tunneling contact parameters: relaxation rates, the localized state coupling, and the tunneling barrier width and height.

  7. Comparative investigation of vibration and current monitoring for prediction of mechanical and electrical faults in induction motor based on multiclass-support vector machine algorithms

    Science.gov (United States)

    Gangsar, Purushottam; Tiwari, Rajiv

    2017-09-01

    This paper presents an investigation of vibration and current monitoring for effective fault prediction in induction motor (IM) by using multiclass support vector machine (MSVM) algorithms. Failures of IM may occur due to propagation of a mechanical or electrical fault. Hence, for timely detection of these faults, the vibration as well as current signals was acquired after multiple experiments of varying speeds and external torques from an experimental test rig. Here, total ten different fault conditions that frequently encountered in IM (four mechanical fault, five electrical fault conditions and one no defect condition) have been considered. In the case of stator winding fault, and phase unbalance and single phasing fault, different level of severity were also considered for the prediction. In this study, the identification has been performed of the mechanical and electrical faults, individually and collectively. Fault predictions have been performed using vibration signal alone, current signal alone and vibration-current signal concurrently. The one-versus-one MSVM has been trained at various operating conditions of IM using the radial basis function (RBF) kernel and tested for same conditions, which gives the result in the form of percentage fault prediction. The prediction performance is investigated for the wide range of RBF kernel parameter, i.e. gamma, and selected the best result for one optimal value of gamma for each case. Fault predictions has been performed and investigated for the wide range of operational speeds of the IM as well as external torques on the IM.

  8. Investigation of the current yaw engineering models for simulation of wind turbines in BEM and comparison with CFD and experiment

    Science.gov (United States)

    Rahimi, H.; Hartvelt, M.; Peinke, J.; Schepers, J. G.

    2016-09-01

    The aim of this work is to investigate the capabilities of current engineering tools based on Blade Element Momentum (BEM) and free vortex wake codes for the prediction of key aerodynamic parameters of wind turbines in yawed flow. Axial induction factor and aerodynamic loads of three wind turbines (NREL VI, AVATAR and INNWIND.EU) were investigated using wind tunnel measurements and numerical simulations for 0 and 30 degrees of yaw. Results indicated that for axial conditions there is a good agreement between all codes in terms of mean values of aerodynamic parameters, however in yawed flow significant deviations were observed. This was due to unsteady phenomena such as advancing & retreating and skewed wake effect. These deviations were more visible in aerodynamic parameters in comparison to the rotor azimuthal angle for the sections at the root and tip where the skewed wake effect plays a major role.

  9. Zinc electrowinning: anode conditioning and current distribution studies

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.A. [Cominco Research, Cominco Ltd., Trail, British Columbia (Canada)

    2001-07-01

    In the zinc electrowinning (EW) process, Pb-Ag anodes are widely used. Prior to their use in the EW process, anodes are conditioned to form a stable oxide layer that can evolve O{sub 2} without excessive Pb contamination of the cathode and MnO{sub 2} precipitation. The most widely used conditioning techniques are: passivation in a KF-H{sub 2}SO{sub 4} electrolysis bath, chemical oxidation in a KMnO{sub 4}-H{sub 2}SO{sub 4} solution, and sandblasting. In this paper, a comparison of these treatments using flat and corrugated anodes is presented. Laboratory and industrial-scale tests carried out at Cominco's Trail and Cajamarquilla zinc plants indicated that flat anodes should be sandblasted or electrochemically passivated before their use in the Zn electrowinning process. Further, corrugated anodes should be sandblasted or chemically conditioned in a KMnO{sub 4}-H{sub 2}SO{sub 4} -electrolyte. The beneficial effects of chemical conditioning are lost if the anode is non-corrugated. Flat, chemically conditioned anodes generate up to 10 times more mud than corrugated-chemically conditioned anodes. Because anode mud growth is evenly distributed on sandblasted anodes, short-circuit frequency may decrease and anode life may increase. Sandblasting does not appear to affect anode performance. Parallel to the industrial anode conditioning tests, current distribution measurements were made. Current flow measurements were used to correct troublesome electrodes and/or bad electrical contacts. In Cajamarquilla, this technique was used in four industrial electrowinning cells and energy consumption values lower than 3000 kWh/t Zn were obtained at current efficiencies as high as 95% and at current densities up to 450 A/m{sup 2}. (author)

  10. 胸腔镜手术在中国地市级医院胸外科应用现状的问卷调查%A Questionnaire Study Investigating Current Application Status of Video-assisted Thoracoscopic Surgery of Thoracic Surgeons in Some Municipal Hospitals in China

    Institute of Scientific and Technical Information of China (English)

    杜恒; 廖虎; 宋志芳; 林琳; 马林; 车国卫; 刘伦旭

    2013-01-01

    ,and provide evidence for further VATS study and training.Methods We conducted a questionnaire study for thoracic surgeons in municipal hospitals who attended the 5th West China Forum on Mini-invasive Thoracic Surgery in 2012.The questionnaire content included general descriptions of the thoracic surgeons,the departments of thoracic surgery where they worked,and VATS application starus in their hospitals.A total of 263 surgeons were investigated,and 183 (69.58%)valid questionnaires were collected for descriptive analysis.Results (1) Responders' view of VATS:There were 89.62% (164/183) responders who believed that the advantages of VATS were mainly mini-invasive and fast postoperative recovery,while its disadvantage was high cost (76.50%,140/183).There were 71.04% (130/183) responders who thought that VATS lobectomy could provide a higher postoperative quality of life for lung cancer patients,while only 12.57% (23/183) responders thought that the 5-year survival rate of VATS was higher than that of open thoracotomy.There were 60.11% (110/183) responders who believed that VATS was less widely performed in China than America,but VATS level of very few hospitals in China was superior or equal to American level.There were 52.46% (96/183) responders who agreed that VATS could be used for the treatment of locally advanced lung cancer.(2)Training situation of VATS lobectomy for lung cancer:Learning class or short-term training (32.24%,59/183)was the best way to learn VATS lobectomy.Their main learning process was from open thoracotomy to mini-thoracotomy then to VATS (60.66%,111/183).Single-direction thoracoscopic lobectomy was the most popular VATS technique (54.64%,100/183),and its learning curve was at least 30 cases (26.78%,49/183).(3) VATS application status:VATS was performed in all the hospitals investigated.Benign thoracic diseases were most commonly chosen by thoracic surgeons who started to perform VATS (81.42%,149/183).The main initial hurdles of

  11. Investigation of current transport parameters of Ti/4H-SiC MPS diode with inhomogeneous barrier

    Institute of Scientific and Technical Information of China (English)

    Song Qing-Wen; Zhang Yu-Ming; Zhang Yi-Men; Chen Feng-Ping; Tang xiao-Yan

    2011-01-01

    The current transport parameters of 4H-SiC merged PiN Schottky (MPS) diode are investigated in a temperature range of 300-520 K. Evaluation of the experimental current-voltage (Ⅰ-Ⅴ) data reveals the decrease in Schottky barrier height φb but an increase in ideality factor n, with temperature decreasing, which suggests the presence of an inhomogeneous Schottky barrier. The current transport behaviours are analysed in detail using the Tung's model and the effective area of the low barrier patches is extracted. It is found that small low barrier patches, making only 4.3% of the total contact, may significantly influence the device electrical characteristics due to the fact that a barrier height of 0.968 eV is much lower than the average barrier height 1.39 eV. This shows that ion implantation in the Schottky contact region of MPS structure may result in a poor Ti/4H-SiC interface quality. In addition, the temperature dependence of the specific on-resistance (Ron-sp), T2.14, is determined between 300 K and 520 K, which is similar to that predicted by a reduction in electron mobility.

  12. 新媒体背景下大学生媒体素养现状调查研究--以河北省部分高校学生为例%Investigation and Research on the Current Situation of College Students' Media Literacy in New Media Back-ground:A Case Study on Some College Students in Hebei Province

    Institute of Scientific and Technical Information of China (English)

    王新; 田明; 李岩芳

    2015-01-01

    When emerging media, such as mobile network, tablet computers, smartphones, , are bringing convenience to college students' life and learning, they also exert certain negative influ-ence. In today's rapid developing emerging media, a pressing matter of the moment for colleges is to strengthen the media liter-acy education of college students. Through investigating the me-dia literacy of some college students in Hebei Province, this pa-per intends to learn about the current situation of college stu-dents' media literacy in Hebei Province, and on this basis, it pro-vides relevant strategies to strengthen the media literacy educa-tion of college students in Hebei Province.%移动网络、平板电脑、智能手机等新兴媒体在给大学生的生活与学习带来便利的同时,也带来了一定的负面影响。在新兴媒体迅速发展的今天,高等院校的当务之急就是要加强大学生媒体素养教育。本文通过对河北省部分高校大学生媒体素养进行调查,了解河北省大学生媒体素养现状,在此基础上,为加强我省大学生媒体素养教育提供相关策略。

  13. A study of current maintenance challenges in a large offshore wind farm

    DEFF Research Database (Denmark)

    Petersen, Kristian Rasmus; Madsen, Erik Skov; Bilberg, Arne

    The aim of the present research project is to obtain a better understanding of the operations and maintenance (O&M) processes that are performed in the offshore wind energy sector. So far, the focus on O&M of offshore wind parks has been very limited and is currently in its early phase. A compara...... used in this study is the case study method. We have followed a team of service-technicians for a longer period of time to investigate their work tasks. This has given an insight in how maintenance jobs are planned, carried out and....

  14. Quantitative study of electrophoretic and electroosmotic enhancement during alternating current iontophoresis across synthetic membranes.

    Science.gov (United States)

    Yan, Guang; Li, S Kevin; Peck, Kendall D; Zhu, Honggang; Higuchi, William I

    2004-12-01

    One of the primary safety and tolerability limitations of direct current iontophoresis is the potential for electrochemical burns associated with the necessary current densities and/or application times required for effective treatment. Alternating current (AC) transdermal iontophoresis has the potential to eliminate electrochemical burns that are frequently observed during direct current transdermal iontophoresis. Although it has been demonstrated that the intrinsic permeability of skin can be increased by applying low-to-moderate AC voltages, transdermal transport phenomena and enhancement under AC conditions have not been systematically studied and are not well understood. The aim of the present work was to study the fundamental transport mechanisms of square-wave AC iontophoresis using a synthetic membrane system. The model synthetic membrane used was a composite Nuclepore membrane. AC frequencies ranging from 20 to 1000 Hz and AC fields ranging from 0.25 to 0.5 V/membrane were investigated. A charged permeant, tetraethyl ammonium, and a neutral permeant, arabinose, were used. The transport studies showed that flux was enhanced by increasing the AC voltage and decreasing AC frequency. Two theoretical transport models were developed: one is a homogeneous membrane model; the other is a heterogeneous membrane model. Experimental transport data were compared with computer simulations based on these models. Excellent agreement between model predictions and experimental data was observed when the data were compared with the simulations from the heterogeneous membrane model.

  15. A study of the current collecting sectors of a U-25B diagonal megnetohydrodynamic generator

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, V.V.; Panovka, M.Ya.; Semenov, V.D.; Sokolov, Yu.N.

    1983-01-01

    The results are cited of an experimental study and a calculated analysis of the operation of current collecting sectors of the U-25B magnetohydrodynamic (MHD) generator. The effect was studied of the parameters of the current, the coefficient of electrical loading, the disposition of the current collecting sectors (T) relative to the diagram of the magnetic field on the distribution of current along the length of the current collecting sectors. It is established that with optimal disposition of the current collecting sectors a uniform distribution of current is achieved. A simplified calculation model of the current collecting sector is developed. It is shown that the experimental and calculated relationships match well. The effect of the ballast resisters installed in the current collecting circuits on the distribution of current is examined. Their positive role in preventing current overloads on the frames and in supporting the uniform distribution of current is noted.

  16. The Study of the Geomagnetic Variation for Sq current System

    Science.gov (United States)

    Zhao, X.; Du, A.

    2012-04-01

    The solar quiet variation (Sq) with a period of 24 hrs is a typical one of the quiet variations. Sq is generally caused by atmospheric tide-dynamo in ionosphere and it is controlled by the electric field, electric conductivity in ionosphere and neutral wind in middle-high altitude atmosphere. In our work, the geomagnetic field data observed by 90 ground-based observatories is used to analyze the local time variation of Sq. Sq is derived from five quiet-day geomagnetic data in every month by the FFT method. According to the pattern of geomagnetic X component in Sq, there is a prenoon-postnoon (before noon and after noon) asymmetry. This asymmetry is obvious in spring, summer and winter. The X component at 12:00-13:00 LT is about 5 nT larger than it at 11:00-12:00 LT. The ratio between the X component of daily variable amplitude and Y component of daily variable amplitude in middle and low (high) latitude regions in summer is greater (smaller) than that in winter. Used the sphere harmonic analysis method, the Sq equivalent current system is obtained. From the pattern of Sq current system, the prenoon-postnoon asymmetry may be caused by the electric field in the high latitude region. This electric field has two effects: the one is that the electric field from high latitude maps to the low latitude region; the other is this electric field penetrate to the middle latitude region directly. The combined action of these two effects makes the prenoon-postnoon asymmetry of Sq. The asymmetry also has an obvious seasonal effect. It may relate to the polar Sq and DP2 in the high latitude region.

  17. The current status of orbital experiments for UHECR studies

    Science.gov (United States)

    Panasyuk, M. I.; Casolino, M.; Garipov, G. K.; Ebisuzaki, T.; Gorodetzky, P.; Khrenov, B. A.; Klimov, P. A.; Morozenko, V. S.; Sakaki, N.; Saprykin, O. A.; Sharakin, S. A.; Takizawa, Y.; Tkachev, L. G.; Yashin, I. V.; Zotov, M. Yu

    2015-08-01

    Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high- transmittance Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (±4.5°), which corresponds to a ground area of 6.4 • 103 km2. The telescope consists of a Fresnel-type mirror-concentrator (∼ 2 m2) and a photo receiver (a matrix of 16 x 16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 m2), which allows decreasing the energy threshold. The total effective field of view will be at least ±14° to exceed the annual exposure of the existing ground-based experiments. Several configurations of the detector are being currently considered. Finally, JEM-EUSO is a wide field of view (±30°) detector. The optics is composed of two curved double-sided Fresnel lenses with 2.65 m external diameter, a precision diffractive middle lens and a pupil. The ultraviolet photons are focused onto the focal surface, which consists of nearly 5000 multi-anode photomultipliers. It is developed by a large international collaboration. All three orbital detectors have multi-purpose character due to continuous monitoring of various atmospheric phenomena. The present status of development of the TUS and KLYPVE missions is reported, and a brief comparison of the projects with JEM-EUSO is given.

  18. Comparative study between an alternating current (AC) and a direct current (DC) electrification of an urban railway

    OpenAIRE

    Garriga Turu, Jordi

    2015-01-01

    This study will evaluate technically, energetic and economically the traction electrification network of the line Barcelona – Vallès operated by Ferrocarrils de la Generalitat de Catalunya (FGC) in the existing voltage system (1500 Vdc) and a new electrification under alternative current (25 kVac) will be proposed to be as well studied. The results obtained will be compared in order to obtain decision factors on which system best fits.

  19. CFD Study of NACA 0018 for Diffuser Design of Tidal Current Turbines

    Directory of Open Access Journals (Sweden)

    Nasir Mehmood

    2012-11-01

    Full Text Available This study is focused on diffuser augmented tidal current turbines that capture the kinetic energy in a tidal stream. The energy that can be extracted from tides is proportional to the cube of the current velocity. The role of the diffuser in diffuser augmented tidal turbines is to help accelerate the incoming current velocity. Consequently, the efficiency of the turbine can be significantly increased by using a diffuser. The research community is investing considerable time and financial resources in this growing domain. The diffuser augmented tidal turbines research data is rather scarce due to their emerging nature, large and costly research and development setup, startup cost and proprietary issues. The purpose of this study is to investigate the effect of length and angle on NACA 0018 airfoil for diffuser design. CFD simulation is carried out to investigate velocity and mass flow rate at the throat. The drag force due to diffuser installation is also calculated. Velocity inside the diffuser increases with diffuser length and angle of attack. Velocity increases up to stall angle and then drops due to flow separation. The drag force is also dominant compared to lift coefficient near stall angle region.

  20. Longitudinal study of spatially heterogeneous emphysema progression in current smokers with chronic obstructive pulmonary disease.

    Directory of Open Access Journals (Sweden)

    Naoya Tanabe

    Full Text Available BACKGROUND: Cigarette smoke is the main risk factor for emphysema, which is a key pathology in chronic obstructive pulmonary disease (COPD. Low attenuation areas (LAA in computed tomography (CT images reflect emphysema, and the cumulative size distribution of LAA clusters follows a power law characterized by the exponent D. This property of LAA clusters can be explained by model simulation, where mechanical force breaks alveolar walls causing local heterogeneous lung tissue destruction. However, a longitudinal CT study has not investigated whether continuous smoking causes the spatially heterogeneous progression of emphysema. METHODS: We measured annual changes in ratios of LAA (LAA%, D and numbers of LAA clusters (LAN in CT images acquired at intervals of ≥ 3 years from 22 current and 31 former smokers with COPD to assess emphysema progression. We constructed model simulations using CT images to morphologically interpret changes in current smokers. RESULTS: D was decreased in current and former smokers, whereas LAA% and LAN were increased only in current smokers. The annual changes in LAA%, D, and LAN were greater in current, than in former smokers (1.03 vs. 0.37%, p=0.008; -0.045 vs. -0.01, p=0.004; 13.9 vs. 1.1, p=0.007, respectively. When LAA% increased in model simulations, the coalescence of neighboring LAA clusters decreased D, but the combination of changes in D and LAN in current smokers could not be explained by the homogeneous emphysema progression model despite cluster coalescence. Conversely, a model in which LAAs heterogeneously increased and LAA clusters merged somewhat in relatively advanced emphysematous regions could reflect actual changes. CONCLUSIONS: Susceptibility to parenchymal destruction induced by continuous smoking is not uniform over the lung, but might be higher in local regions of relatively advanced emphysema. These could result in the spatially heterogeneous progression of emphysema in current smokers.

  1. Aspartame: a safety evaluation based on current use levels, regulations, and toxicological and epidemiological studies.

    Science.gov (United States)

    Magnuson, B A; Burdock, G A; Doull, J; Kroes, R M; Marsh, G M; Pariza, M W; Spencer, P S; Waddell, W J; Walker, R; Williams, G M

    2007-01-01

    Aspartame is a methyl ester of a dipeptide used as a synthetic nonnutritive sweetener in over 90 countries worldwide in over 6000 products. The purpose of this investigation was to review the scientific literature on the absorption and metabolism, the current consumption levels worldwide, the toxicology, and recent epidemiological studies on aspartame. Current use levels of aspartame, even by high users in special subgroups, remains well below the U.S. Food and Drug Administration and European Food Safety Authority established acceptable daily intake levels of 50 and 40 mg/kg bw/day, respectively. Consumption of large doses of aspartame in a single bolus dose will have an effect on some biochemical parameters, including plasma amino acid levels and brain neurotransmitter levels. The rise in plasma levels of phenylalanine and aspartic acid following administration of aspartame at doses less than or equal to 50 mg/kg bw do not exceed those observed postprandially. Acute, subacute and chronic toxicity studies with aspartame, and its decomposition products, conducted in mice, rats, hamsters and dogs have consistently found no adverse effect of aspartame with doses up to at least 4000 mg/kg bw/day. Critical review of all carcinogenicity studies conducted on aspartame found no credible evidence that aspartame is carcinogenic. The data from the extensive investigations into the possibility of neurotoxic effects of aspartame, in general, do not support the hypothesis that aspartame in the human diet will affect nervous system function, learning or behavior. Epidemiological studies on aspartame include several case-control studies and one well-conducted prospective epidemiological study with a large cohort, in which the consumption of aspartame was measured. The studies provide no evidence to support an association between aspartame and cancer in any tissue. The weight of existing evidence is that aspartame is safe at current levels of consumption as a nonnutritive

  2. Investigation of the influence of image reconstruction filter and scan parameters on operation of automatic tube current modulation systems for different CT scanners.

    Science.gov (United States)

    Sookpeng, Supawitoo; Martin, Colin J; Gentle, David J

    2015-03-01

    Variation in the user selected CT scanning parameters under automatic tube current modulation (ATCM) between hospitals has a substantial influence on the radiation doses and image quality for patients. The aim of this study was to investigate the effect of changing image reconstruction filter and scan parameter settings on tube current, dose and image quality for various CT scanners operating under ATCM. The scan parameters varied were pitch factor, rotation time, collimator configuration, kVp, image thickness and image filter convolution (FC) used for reconstruction. The Toshiba scanner varies the tube current to achieve a set target noise. Changes in the FC setting and image thickness for the first reconstruction were the major factors affecting patient dose. A two-step change in FC from smoother to sharper filters doubles the dose, but is counterbalanced by an improvement in spatial resolution. In contrast, Philips and Siemens scanners maintained tube current values similar to those for a reference image and patient, and the tube current only varied slightly for changes in individual CT scan parameters. The selection of a sharp filter increased the image noise, while use of iDose iterative reconstruction reduced the noise. Since the principles used by CT manufacturers for ATCM vary, it is important that parameters which affect patient dose and image quality for each scanner are made clear to operator to aid in optimisation.

  3. Using Baseline Studies in the Investigation of Test Impact

    Science.gov (United States)

    Wall, Dianne; Horak, Tania

    2007-01-01

    The purpose of this article is to discuss the role of "baseline studies" in investigations of test impact and to illustrate the type of thinking underlying the design and implementation of such studies by reference to a recent study relating to a high-stakes test of English language proficiency. Baseline studies are used to describe an educational…

  4. The current status of orbital experiments for UHECR studies

    CERN Document Server

    Panasyuk, M I; Garipov, G K; Ebisuzaki, T; Gorodetzky, P; Khrenov, B A; Klimov, P A; Morozenko, V S; Sakaki, N; Saprykin, O A; Sharakin, S A; Takizawa, Y; Tkachev, L G; Yashin, I V; Zotov, M Yu

    2015-01-01

    Two types of orbital detectors of extreme energy cosmic rays are being developed nowadays: (i) TUS and KLYPVE with reflecting optical systems (mirrors) and (ii) JEM-EUSO with high-transmittance Fresnel lenses. They will cover much larger areas than existing ground-based arrays and almost uniformly monitor the celestial sphere. The TUS detector is the pioneering mission developed in SINP MSU in cooperation with several Russian and foreign institutions. It has relatively small field of view (+/-4.5 deg), which corresponds to a ground area of 6.4x10^3 sq.km. The telescope consists of a Fresnel-type mirror-concentrator (~2 sq.m) and a photo receiver (a matrix of 16x16 photomultiplier tubes). It is to be deployed on the Lomonosov satellite, and is currently at the final stage of preflight tests. Recently, SINP MSU began the KLYPVE project to be installed on board of the Russian segment of the ISS. The optical system of this detector contains a larger primary mirror (10 sq.m), which allows decreasing the energy thr...

  5. Current studies on human papillomavirus in Saudi Arabia.

    Science.gov (United States)

    Alhamlan, Fatimah Saeed; Al-Qahtani, Ahmed A; Al-Ahdal, Mohammed N

    2015-07-04

    Human papillomavirus (HPV) infection is a significant etiological factor and an important prognosticator in cervical cancer. Indeed, researchers worldwide have confirmed these roles for high-risk HVPs in over 70% of cervical cancer cases. According to the World Health Organization, approximately 561,200 new cancer cases (5.2% of all new cancers) are attributed to HPV infection. Over 120 types of HPV are classified further as either low-risk HPV (LR-HPV) or high-risk HPV (HR-HPV) based on their oncological potential of transforming cells. The LR-HPV types cause benign hyperproliferative lesions (i.e. genital warts) while the HR-HPV types are strongly associated with premalignant and malignant cervical lesions. Data on the prevalence of HPV, survival of infected patients, and mortality rate are scarce in Saudi Arabia. The unsubstantiated assumption of a low prevalence of HPV in Saudi Arabia has contributed to limiting HPV research in this conservative country. Therefore, the goal of this review is to shed light on the current HPV research being conducted and the prevalence of HPV in Saudi Arabia.

  6. Retooling the Social Studies Classroom for the Current Generation

    Science.gov (United States)

    Wilson, Elizabeth K.; Wright, Vivian H.; Inman, Christopher T.; Matherson, Lisa H.

    2011-01-01

    Digital technologies have changed the way students read and communicate. Subsequently, teachers must use technology to engage their students in learning. This article illustrates the value of using Web 2.0 tools (blogs, wikis, and digital media-sharing) in the social studies classroom. Additionally, a social studies teacher shares insights into…

  7. A Review of Current Studies on Human Capital

    Institute of Scientific and Technical Information of China (English)

    黄思雅

    2012-01-01

      This paper introduces some previous studies on human capital, mainly regarding human capital’s properties and its relationship with corporate performance and capital structure. This study shows the importance of human capital and suggests that managers should pay more attention to employees.

  8. Investigation of Current-Voltage Characteristics of Ni/GaN Schottky Barrier Diodes for Potential HEMT Applications

    Directory of Open Access Journals (Sweden)

    Ashish Kumar

    2011-01-01

    Full Text Available In the present work, the I-V characteristics of Ni/GaN Schottky diodes have been studied. The Schottky diodes, having different sizes using Ni/Au and ohmic contacts using Ti/Al/Ni/Au were made on n-GaN. The GaN was epitaxially grown on c-plane sapphire by metal organic chemical vapor deposition (MOCVD technique and had a thickness of about 3.7 µm. The calculated ideality factor and barrier height from current-voltage (I-V characteristics (at 300 K for two GaN Schottky diodes were close to ~1.3 and ~ 0.8 eV respectively. A high reverse leakage current in the order of 10 – 4A/cm2 (at – 1 V was observed in both diodes. A careful analysis of forward bias I-V characteristics showed very high series resistance and calculation for ideality factor indicated presence of other current transport mechanism apart from thermionic model at room temperature.

  9. Review of current study methods for VRU safety

    DEFF Research Database (Denmark)

    Andersen, Camilla Sloth; Kamaluddin, Noor Azreena; Várhelyi, András

    written questionnaires (either online or paper-based), interviews may be performed (either face-to-face or via telephone) and people may be asked to report their accident via an app on their mobile device. The method for gaining self-reported information thus varies greatly – and so does the information...... that people are asked to give. In most studies, only the number of accidents in which the respondent was involved is relevant for the researcher. In other studies, respondents are asked about possible accident causation factors, and some studies deal with respondents’ recall of the accident details. In other...

  10. Current approaches of genome-wide association studies

    Institute of Scientific and Technical Information of China (English)

    Jianfeng Xu

    2008-01-01

    @@ With rapid advances in high-throughput genotyping technology and the great increase in information available on SNPs throughout the genuine, genuine-wide association(GWA) studies have now become feasible.

  11. Cost-of-Illness Studies: A Review of Current Methods

    OpenAIRE

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

    2006-01-01

    The number of cost-of-illness (COI) studies has expanded considerably over time. One outcome of this growth is that the reported COI estimates are inconsistent across studies, thereby raising concerns over the validity of the estimates and methods. Several factors have been identified in the literature as reasons for the observed variation in COI estimates. To date, the variation in the methods used to calculate costs has not been examined in great detail even though the variations in methods...

  12. The study of Zn–Co alloy coatings electrochemically deposited by pulse current

    Directory of Open Access Journals (Sweden)

    Tomić Milorad V.

    2012-01-01

    Full Text Available The electrochemical deposition by pulse current of Zn-Co alloy coatings on steel was examined, with the aim to find out whether pulse plating could produce alloys that could offer a better corrosion protection. The influence of on-time and the average current density on the cathodic current efficiency, coating morphology, surface roughness and corrosion stability in 3% NaCl was examined. At the same Ton/Toff ratio the current efficiency was insignificantly smaller for deposition at higher average current density. It was shown that, depending on the on-time, pulse plating could produce more homogenous alloy coatings with finer morphology, as compared to deposits obtained by direct current. The surface roughness was the greatest for Zn-Co alloy coatings deposited with direct current, as compared with alloy coatings deposited with pulse current, for both examined average current densities. It was also shown that Zn-Co alloy coatings deposited by pulse current could increase the corrosion stability of Zn-Co alloy coatings on steel. Namely, alloy coatings deposited with pulse current showed higher corrosion stability, as compared with alloy coatings deposited with direct current, for almost all examined cathodic times, Ton. Alloy coatings deposited at higher average current density showed greater corrosion stability as compared with coatings deposited by pulse current at smaller average current density. It was shown that deposits obtained with pulse current and cathodic time of 10 ms had the poorest corrosion stability, for both investigated average deposition current density. Among all investigated alloy coatings the highest corrosion stability was obtained for Zn-Co alloy coatings deposited with pulsed current at higher average current density (jav = 4 A dm-2.

  13. Holistic Investigation of Corona Discharge: Impulse Current Waveform and Phase-resolved Measurement, Analysis and Simulation%Holistic Investigation of Corona Discharge: Impulse Current Waveform and Phase-resolved Measurement, Analysis and Simulation

    Institute of Scientific and Technical Information of China (English)

    Suwarno

    2011-01-01

    Partial discharge(PD) is one of the most important phenomenon in high voltage insulations. In most cases, the appearance of partial discharges is related to insulation defects. Understanding partial discharges is important for diagnosis on insulation condition. Corona discharges appear when extremely high electric field appears on the conductor surface exceeding the electric field strength of the gas. The high electric field may occur at around protrusion with very sharp tip. This paper reported a holistic approach of corona discharge investigation. The needle--plane electrode system was used. The medium between the electrodes was air. The needle was made from steel with radius of curvature of 3 μm (Ogura needle). Sinusoidal as well as triangular applied voltages were used. The waveform of the corona discharges was measured using a digital oscilloscope. The corona discharge pulses were measured using a phase--re- solved PD measurement system. The system was able to measure the magnitude (q) and phase angle position (9) of each PD pulses, as well as the number of discharge pulses (n). The role of applied voltage was investigated using phase--resolved analysis of corona discharge pulses through pulse sequence, pulse magnitude and pulse number analy- sis. Experimental results indicated that corona discharge current waveform was an impulse with rise time of about several ns and the impulse width of about 100 ns. The Fast Fourier Transform analysis indicated that the corona discharge current waveform had several spectrum peaks at frequency of 7.8 MHz, 85.9 MHz, 109.4 MHz and 195.3 MHz. The experimental results also showed that discharge pulses were concentrated around the peak of applied voltage for both sinusoidal and triangular voltages. The discharge magnitude, as well as its probability of occurrence, was strongly dependent on the instantaneous applied voltage. The shape of φn, as well as φ-q-n PD patterns, were strongly reflected by the shape

  14. Admittance Modeling of Voltage and Current Controlled Inverter for Harmonic Instability Studies

    DEFF Research Database (Denmark)

    Hoseinzadeh, Bakhtyar; Bak, Claus Leth

    2016-01-01

    This paper proposes an impedance/admittance based model for voltage and current controlled inverters with passive elements suitable for harmonic instability study of grid connected inverters in frequency domain. This linearized model of inverters, significantly simplifies investigation of resonance...... instability and control loop interaction of wind turbines with each other and/or with the grid, while they are installed in wind farms. The derived impedance ratio at point of common connection demonstrates how the inverters participate in harmonic stability of the grid....

  15. A study on the interference effects for tidal current power rotors

    Institute of Scientific and Technical Information of China (English)

    Chul-Hee; JO; Kang-Hee; LEE; Jin-Young; YIM

    2010-01-01

    Due to global warming, the need to secure an alternative resource has become more important nationally. With the high tidal range of up to 9.7 m on the west coast of Korea, numerous tidal current projects are being planned and constructed. To extract a significant quantity of power, a tidal current farm with a multi-arrangement is necessary in the ocean. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system, and its performance is determined by various design variables. The power generation is strongly dependent on the size of the rotor and the incoming flow velocity. However, the interactions between devices also contribute significantly to the total power capacity. Therefore, rotor performance considering the interaction problems needs to be investigated for generating maximum power in a specific field. This paper documents a performance study of devices considering the interference between rotating rotors with axial, transverse and diagonal arrangements.

  16. The Course of Schizophrenia: E. Kraepelin's View and Current Studies

    Directory of Open Access Journals (Sweden)

    Norbert Müller

    2014-10-01

    Full Text Available Kraepelin's concept of dementia praecox and Bleuler's concept of the group of schizophrenias differ mainly under the aspect of course of the disorder. Follow-up studies play an important role for research regarding course, outcome and prognosis of psychiatric disorders, especially in terms of validation of psychiatric diagnosis and other psychiatric concepts, such as the concept of schizophrenic negative symptoms. Long-term studies also have their place in the description and evaluation of first treatment procedures. This paper will describe some general aspects of the long-term course and outcome of schizophrenic psychoses. The problem of relapses and relapse prevention will then be discussed. Especially data from recent studies will be considered in this overview.

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

    Science.gov (United States)

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

    2007-05-01

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

  18. The Investigation of Separability of Particles Smaller Than 5 mm by Eddy Current Separation Technology. Part I: Rotating Type Eddy Current Separators

    NARCIS (Netherlands)

    Zhang, S.; Rem, P.C.; Forssberg, E.

    1999-01-01

    Owing to the growing emergence of the end-of-life electrical and electronic products with complex material structures and an ever-diminishing particle size of the valuable metals involved, development of eddy current separators (ECS) has been targeting selective separation of small non-ferrous metal

  19. Investigative study of standards for Digital Repositories and related services

    NARCIS (Netherlands)

    Foulonneau, Muriel; André, Francis

    2007-01-01

    This study is meant for institutional repository managers, service providers, repository software developers and generally, all players taking an active part in the creation of the digital repository infrastructure for e-research and e-learning. It reviews the current standards, protocols and applic

  20. Investigating stakeholders' perceptions of the link between high STD rates and the current Baltimore City Public Schools' sex education curriculum

    Science.gov (United States)

    Bolden, Shenell L. T.

    The purpose of this exploratory study was to examine key stakeholders' perceptions of the current Baltimore City Public Schools' (BCPS) sex education curriculum and to gain insight into how they believe the curriculum could be modified to be more effective. A mixed methods approach using qualitative and quantitative data collection consisting of a survey, focus group interview, and individual interviews was conducted to gather information on stakeholders' perceptions. The stakeholders included: (1) former students who received their sex education courses in the Baltimore City Public School system (BCPS); (2) teachers in BCPS who were affiliated with the sex education curriculum; (3) health care professionals who screened and/or treated East Baltimore City residents for a sexually transmitted disease (STD) and; (4) one policy maker who was responsible for creating sex education curriculum at the national level. Analysis of the quantitative data from former Baltimore City Public School students revealed a general satisfaction with the current sex education curriculum. However, qualitative data from the same group of stakeholders revealed several changes they thought should be implemented into the program in an effort to improve the current curriculum. Findings from the other groups after qualitative analysis of the interviews suggest three major themes in support of curriculum change: (1) a blended curriculum that integrates both the cognitive and affective learning domains; (2) knowledge of prevention of STD's and pregnancy; and (3) authentic teaching and learning. Results from this study strongly suggest that the Baltimore City Public School system is apathetic to the sexual health needs of students and, therefore, is inadvertently contributing to the high rate of sexually transmitted diseases among young people. Keywords: Abstinence, Affective domain, Indoctrination, Behavior Modification, Cognitive domain, Sex education curriculum, Sexually Transmitted Diseases.

  1. Organ preconditioning: the past, current status, and related lung studies

    Institute of Scientific and Technical Information of China (English)

    LUH Shi-ping; YANG Pan-chyr

    2006-01-01

    Preconditioning (PC) has emerged as a powerful method for experimentally and clinically attenuating various types of organ injuries. In this paper related clinical and basic research issues on organ preconditioning issues were systemically reviewed.Since lung injuries, including ischemia-reperfusion and others, play important roles in many clinical results, including thromboembolism, trauma, thermal injury, hypovolemic and endotoxin shock, reimplantation response after organ transplantation, and many respiratory diseases in critical care. It is of interest to uncover methods, including the PCs, to protect the lung from the above injuries. However, related studies on pulmonary PC are relatively rare and still being developed, so we will review previous literature on experimental and clinical studies on pulmonary PC in the following paragraphs.

  2. Animal venom studies: Current benefits and future developments

    Institute of Scientific and Technical Information of China (English)

    Yuri; N; Utkin

    2015-01-01

    Poisonous organisms are represented in many taxa, including kingdom Animalia. During evolution, animals have developed special organs for production and injection of venoms. Animal venoms are complex mixtures, compositions of which depend on species producing venom. The most known and studied poisonous terrestrial animals are snakes, scorpions and spiders. Among marine animals, these are jellyfishes, anemones and cone snails. The toxic substances in the venom ofthese animals are mainly of protein and peptide origin. Recent studies have indicated that the single venom may contain up to several hundred different components producing diverse physiological effects. Bites or stings by certain poisonous species result in severe envenomations leading in some cases to death. This raises the problem of bite treatment. The most effective treatment so far is the application of antivenoms. To enhance the effectiveness of such treatments, the knowledge of venom composition is needed. On the other hand, venoms contain substances with unique biological properties, which can be used both in basic science and in clinical applications. The best example of toxin application in basic science is α-bungarotoxin the discovery of which made a big impact on the studies of nicotinic acetylcholine receptor. Today compositions of venom from many species have already been examined. Based on these data, one can conclude that venoms contain a large number of individual components belonging to a limited number of structural types. Often minor changes in the amino acid sequence give rise to new biological properties. Change in the living conditions of poisonous animals lead to alterations in the composition of venoms resulting in appearance of new toxins. At the same time introduction of new methods of proteomics and genomics lead to discoveries of new compounds, which may serve as research tools or as templates for the development of novel drugs. The application of these sensitive and

  3. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    OpenAIRE

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah

    2007-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came...

  4. Electrophysiological studies of malaria parasite-infected erythrocytes: Current status

    Science.gov (United States)

    Staines, Henry M.; Alkhalil, Abdulnaser; Allen, Richard J.; De Jonge, Hugo R.; Derbyshire, Elvira; Egée, Stéphane; Ginsburg, Hagai; Hill, David A.; Huber, Stephan M.; Kirk, Kiaran; Lang, Florian; Lisk, Godfrey; Oteng, Eugene; Pillai, Ajay D.; Rayavara, Kempaiah; Rouhani, Sherin; Saliba, Kevin J.; Shen, Crystal; Solomon, Tsione; Thomas, Serge L. Y.; Verloo, Patrick; Desai, Sanjay A.

    2009-01-01

    The altered permeability characteristics of erythrocytes infected with malaria parasites have been a source of interest for over 30 years. Recent electrophysiological studies have provided strong evidence that these changes reflect transmembrane transport through ion channels in the host erythrocyte plasma membrane. However, conflicting results and differing interpretations of the data have led to confusion in this field. In an effort to unravel these issues, the groups involved recently came together for a week of discussion and experimentation. In this article, the various models for altered transport are reviewed, together with the areas of consensus in the field and those that require a better understanding. PMID:17292372

  5. Investigation of the effects of transcranial alternating current stimulation (tACS) on self-paced rhythmic movements.

    Science.gov (United States)

    Varlet, Manuel; Wade, Alanna; Novembre, Giacomo; Keller, Peter E

    2017-03-18

    Human rhythmic movements spontaneously entrain to external rhythmic stimuli. Such sensory-motor entrainment can attract movements to different tempi and enhance their efficiency, with potential clinical applications for motor rehabilitation. Here we investigate whether entrainment of self-paced rhythmic movements can be induced via transcranial alternating current stimulation (tACS), which uses alternating currents to entrain spontaneous brain oscillations at specific frequencies. Participants swung a handheld pendulum at their preferred tempo with the right hand while tACS was applied over their left or right primary motor cortex at frequencies equal to their preferred tempo (Experiment 1) or in the alpha (10Hz) and beta (20Hz) ranges (Experiment 2). Given that entrainment generally occurs only if the frequency difference between two rhythms is small, stimulations were delivered at frequencies equal to participants' preferred movement tempo (≈1Hz) and ±12.5% in Experiment 1, and at 10Hz and 20Hz, and ±12.5% in Experiment 2. The comparison of participants' movement frequency, amplitude, variability, and phase synchrony with and without tACS failed to reveal entrainment or movement modifications across the two experiments. However, significant differences in stimulation-related side effects reported by participants were found between the two experiments, with phosphenes and burning sensations principally occurring in Experiment 2, and metallic tastes reported marginally more often in Experiment 1. Although other stimulation protocols may be effective, our results suggest that rhythmic movements such as pendulum swinging or locomotion that are low in goal-directedness and/or strongly driven by peripheral and mechanical constraints may not be susceptible to modulation by tACS.

  6. Current studies on physiological functions and biological production of lactosucrose.

    Science.gov (United States)

    Mu, Wanmeng; Chen, Qiuming; Wang, Xiao; Zhang, Tao; Jiang, Bo

    2013-08-01

    Lactosucrose (O-β-D-galactopyranosyl-(1,4)-O-α-D-glucopyranosyl-(1,2)-β-D-fructofuranoside) is a trisaccharide formed from lactose and sucrose by enzymatic transglycosylation. This rare trisaccharide is a kind of indigestible carbohydrate, has good prebiotic effect, and promotes intestinal mineral absorption. It has been used as a functional ingredient in a range of food products which are approved as foods for specified health uses in Japan. Using lactose and sucrose as substrates, lactosucrose can be produced through transfructosylation by β-fructofuranosidase from Arthrobacter sp. K-1 or a range of levansucrases, or through transgalactosylation by β-galactosidase from Bacillus circulans. This article presented a review of recent studies on the physiological functions of lactosucrose and the biological production from lactose and sucrose by different enzymes.

  7. Descriptive currents in philosophy of religion for Hebrew Bible studies

    Directory of Open Access Journals (Sweden)

    Jacobus W. Gericke

    2011-03-01

    Full Text Available This article argued that the utilisation of philosophy of religion in the study of the Hebrew Bible is possible if we look beyond the stereotype of erroneously equating the auxiliary field with natural theology, apologetics or atheological criticism. Fruitful possibilities for interdisciplinary research are available in the form of descriptive varieties of philosophy of religion primarily concerned with understanding and the clarification of meaning rather than with the stereotypical tasks of propositional justification or critical evaluation. Three examples are discussed in the article: analytic traditions (Wittgensteinianism and ordinarylanguage philosophy, phenomenological perspectives involving reduction (bracketing and comparative philosophy of religion that works in tandem with the history of religion and comparative religion.

  8. Current state of epidemiological studies in Belarus about Chernobyl sufferers

    Energy Technology Data Exchange (ETDEWEB)

    Matsko, V.P. [Institute of Radiobiology, Academy Sciences of Belarus, Minsk (Belarus)

    1998-03-01

    The present paper is an analysis of the results of epidemiological studies in Belarus about the after-effects of the accident at the Chernobyl atomic power station (ChAPS), based on published data at scientific institutes, organs and institutions of Ministry of Health. In the last years the affected population showed thereby more significant - as compared with republican indices - growth of incidence in the majority of diseases (first of all: digestion, urogenital, nervous, endocrine systems, diseases of ear, throat, nose both among adults and among children). Aggravation of health state continues in the participants of liquidation of the ChAPS accident consequences and the evacuees from the alienation zone which have obtained considerable radiation load to organism (rise of incidence of diseases of endocrine, cardiovascular, nervous system etc.). Considerable growth of thyroid cancer incidence is registered in Belarus children and adolescents, especially in the Gomel and Brest regions. This is conditioned by dose commitments on thyroid gland due to iodine radionuclides in first period after the accident, incorrect iodine prophylaxy, and goitre endemic. The rise of hereditary pathology is registered too. An expressed increase of oncological diseases is observed therewith mainly in the Gomel region, especially in the districts with high level of radiocontamination and, consequently, significant radiation load. First of all, this relates to the growth of incidence of cancer of lungs, mammary gland, bladder. The analysis of epidemiological studies performed in Belarus after the ChAPS catastrophe and comparison of them with data obtained in the pre-Chernobyl period testify to the aggravation of health state of Belarus population. The specialists unambiguously recognize the direct influence of radioactive pollution in the environment on rise of thyroid pathologies, hereditary and congenial diseases, and cancers of different localizations. There is no unique opinion

  9. Stuttering in Lima, Peru: a qualitative case study of current concepts, theories, and treatment facilities.

    Science.gov (United States)

    Gorin, L C

    1980-07-01

    The purpose of this study was to investigate within an ethnographic framework, certain cultural variables which may be factors in the etiology and presentation of stuttering as well as in the care provided for those who stutter. An assessment was made of the cultural influences upon the following variables of the transcultural investigation of stuttering: 1) epidemiological characteristics of stuttering; 2) attitudes of the stutterer and the stutterer's family, friends, therapists towards the defect; 3) cultural expectations which may be part of the etiology/perpetuation of the problem of stuttering, including an examination of these cultural expectations within the context of the stutterer's past and present home, work, and recreational lifestyles: 4) current theories and therapies.

  10. Dosage considerations for transcranial direct current stimulation in children: a computational modeling study.

    Directory of Open Access Journals (Sweden)

    Sudha Kilaru Kessler

    Full Text Available Transcranial direct current stimulation (tDCS is being widely investigated in adults as a therapeutic modality for brain disorders involving abnormal cortical excitability or disordered network activity. Interest is also growing in studying tDCS in children. Limited empirical studies in children suggest that tDCS is well tolerated and may have a similar safety profile as in adults. However, in electrotherapy as in pharmacotherapy, dose selection in children requires special attention, and simple extrapolation from adult studies may be inadequate. Critical aspects of dose adjustment include 1 differences in neurophysiology and disease, and 2 variation in brain electric fields for a specified dose due to gross anatomical differences between children and adults. In this study, we used high-resolution MRI derived finite element modeling simulations of two healthy children, ages 8 years and 12 years, and three healthy adults with varying head size to compare differences in electric field intensity and distribution. Multiple conventional and high-definition tDCS montages were tested. Our results suggest that on average, children will be exposed to higher peak electrical fields for a given applied current intensity than adults, but there is likely to be overlap between adults with smaller head size and children. In addition, exposure is montage specific. Variations in peak electrical fields were seen between the two pediatric models, despite comparable head size, suggesting that the relationship between neuroanatomic factors and bioavailable current dose is not trivial. In conclusion, caution is advised in using higher tDCS doses in children until 1 further modeling studies in a larger group shed light on the range of exposure possible by applied dose and age and 2 further studies correlate bioavailable dose estimates from modeling studies with empirically tested physiologic effects, such as modulation of motor evoked potentials after stimulation.

  11. Work Plan for a Limited CCC/USDA Investigation of the Current Carbon Tetrachloride Contamination in Groundwater at Navarre, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    LaFreniere, Lorraine M. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2014-05-01

    During private well testing in 1990-1991, carbon tetrachloride was identified in the groundwater at several locations in the town of Navarre, Kansas, at levels exceeding the Kansas Tier 2 level and U.S. Environmental Protection Agency (EPA) maximum contaminant level (MCL) of 5.0 μg/L. Several subsequent investigations through 2006 evaluated the concentrations and distribution of carbon tetrachloride in groundwater. This work included the identification of the contaminant sources (Argonne 2007). The history of activities to address the contamination in soil and groundwater is summarized in Table 1.1. The most recent studies, conducted by the Kansas Department of Health and Environment (KDHE), include a brownfields investigation initiated in 2013 (Phase I) and continuing in early 2014 (Phase II), as well as private well testing.

  12. 42 CFR 431.713 - Continuing study and investigation.

    Science.gov (United States)

    2010-10-01

    ... SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS STATE ORGANIZATION AND GENERAL ADMINISTRATION State Programs for Licensing Nursing Home Administrators § 431.713 Continuing study and investigation. The agency or board must conduct a continuing study of nursing homes and administrators within the State...

  13. The Current Status of Usability Studies of Information Technologies in China: A Systematic Study

    OpenAIRE

    Lei, Jianbo; Xu, Lufei; Meng, Qun; Zhang, Jiajie; Gong, Yang

    2014-01-01

    Objectives. To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. Methods. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Results. Six hundred forty-seven publications were selected for analysis. We found ...

  14. The relationship between attitudes towards menarche and current attitudes towards menstruation of women: A comparative study

    Directory of Open Access Journals (Sweden)

    Nülüfer Erbil

    2015-11-01

    Full Text Available Purpose: The study was conducted to determine affecting factors and to investigate relationship  between  attitudes towards menarche and current attitudes towards menstruation of women and to compare characteristics of menarche and menstruation of women who were born and raised in the northeastern and western of Turkey.  Method and Materials: This descriptive and comparative study was participated totally 400 volunteer women. The data were collected using a questionnaire containing defined closed and open-ended questions. Results: The study results showed that women living in Ordu province than women living in Aydın province expressed positive attitudes toward menarche, and the difference was found significant. Nevertheless, attitudes towards current menstruation were similar in both provinces. When the data of 400 women were evaluated together; women’s attitudes towards menarche were compared with the current attitudes towards menstruation, and the difference was found statistically significant. Although attitudes of the women towards menarche varied according to where they lived, their current attitudes towards menstruation were similar. In addition, depending upon the province, there were statistically significant differences in women’s age at menarche, recollection of menarche, and feelings of shame or happiness at menarche, source and adequacy of information about menstruation, and regularity of their menstrual cycle.   Conclusions: Early menstrual experiences may be related to menstrual experiences later in life and women’s attitudes towards menstruation were not affected by geographical locations. In order to develop positive attitudes towards menarche and a woman’s future years of menstrual cycles, it is very important that accurate and adequate information for young girls be provided before menarche.

  15. An actigraphy study investigating sleep in bipolar I patients, unaffected siblings and controls

    NARCIS (Netherlands)

    Verkooijen, Sanne; van Bergen, Annet H.; Knapen, Stefan E.; Vreeker, Annabel; Abramovic, Lucija; Pagani, Lucia; Jung, Yoon; Riemersma-van der Lek, Rixt; Schoevers, Robert A.; Takahashi, Joseph S.; Kahn, Rene S.; Boks, Marco P. M.; Ophoff, Roel A.

    2017-01-01

    Objectives: Disturbances in sleep and waking patterns are highly prevalent during mood episodes in bipolar disorder. The question remains whether these disturbances persist during phases of euthymia and whether they are heritable traits of bipolar disorder. The current study investigates objective

  16. Modeling studies of the coastal/littoral current system off Southern Australia

    OpenAIRE

    Miller, Henry A.

    2006-01-01

    Both theoretical and numerical modeling studies of the current system off western and southern Australia are conducted to characterize the features of the current system, their temporal variability, and their impact on the sound speed structure. The theoretical study examines why boundary current separation occurs off Cape Leeuwin creating an area of enhanced eddy generation. It is shown that the beta effect, vortex stretching, and streamline curvature all act to decelerate the current a...

  17. Microdialysis sampling for investigations of bioavailability and bioequivalence of topically administered drugs: current state and future perspectives

    DEFF Research Database (Denmark)

    Holmgaard, R; Nielsen, J B; Benfeldt, E

    2010-01-01

    Microdialysis (MD) in the skin is a unique technique for in vivo sampling of topically as well as systemically administered drugs at the site of action, e.g. sampling the unbound tissue concentrations in the dermis and subcutaneous tissue. MD as a research method has undergone significant...... by skin disease or barrier perturbation. A comparison between MD and other tissue sampling techniques reveals the advantages and limitations of the method. Subsequently, an in-depth discussion of the application of MD for the evaluation of bioavailability and bioequivalence of topical formulations...... development, improvement and validation during the last decade and has proved to be a versatile, safe and valuable tool for pharmacokinetic and pharmacodynamic studies. This review gives an overview of the current state and future perspectives of dermal MD sampling. Methodological issues such as choice...

  18. Modeling Studies of Eddies in the Leeuwin Current: The Role of Thermal Forcing

    OpenAIRE

    Batteen, Mary L.; Rutherford, Martin J.

    1990-01-01

    A high resolution, multilevel, primitive equation (PE) model is used to investigate the generation and stability of the Leeuwin Current and eddies off the west coast of Australia. Two numerical experiments are conducted to investigate the roles of the Indian Ocean temperature field and the North West (NW) Shelf waters in generating both the current and eddies. In the first experiment an alongshore temperature gradient, typical of the Indian Ocean temperature field, is imposed, whi...

  19. Estimating the effect of current, previous and never use of drugs in studies based on prescription registries

    DEFF Research Database (Denmark)

    Nielsen, Lars Hougaard; Løkkegaard, Ellen; Andreasen, Anne Helms;

    2009-01-01

    PURPOSE: Many studies which investigate the effect of drugs categorize the exposure variable into never, current, and previous use of the study drug. When prescription registries are used to make this categorization, the exposure variable possibly gets misclassified since the registries do not ca...... with Hazard Ratios ranging from 1.68 to 1.78 for current use compared to never use. CONCLUSIONS: The findings suggest that it is possible to estimate the effect of never, current and previous use of HT on breast cancer using prescription data.......PURPOSE: Many studies which investigate the effect of drugs categorize the exposure variable into never, current, and previous use of the study drug. When prescription registries are used to make this categorization, the exposure variable possibly gets misclassified since the registries do...... not carry any information on the time of discontinuation of treatment.In this study, we investigated the amount of misclassification of exposure (never, current, previous use) to hormone therapy (HT) when the exposure variable was based on prescription data. Furthermore, we evaluated the significance...

  20. Equity perceptions and marital satisfaction in former and current marriage : A study among the remarried

    NARCIS (Netherlands)

    Buunk, BP; Mutsaers, W

    1999-01-01

    A study among 290 remarried individuals examined equity perceptions in the former and the current marriage. The results showed that equity in the former and the current marriage were not related to each other. In general, respondents perceived much more inequity in the former than in the current mar

  1. Induced pluripotent stem cells reveal functional differences between drugs currently investigated in patients with hutchinson-gilford progeria syndrome.

    Science.gov (United States)

    Blondel, Sophie; Jaskowiak, Anne-Laure; Egesipe, Anne-Laure; Le Corf, Amelie; Navarro, Claire; Cordette, Véronique; Martinat, Cécile; Laabi, Yacine; Djabali, Karima; de Sandre-Giovannoli, Annachiara; Levy, Nicolas; Peschanski, Marc; Nissan, Xavier

    2014-04-01

    Hutchinson-Gilford progeria syndrome is a rare congenital disease characterized by premature aging in children. Identification of the mutation and related molecular mechanisms has rapidly led to independent clinical trials testing different marketed drugs with a preclinically documented impact on those mechanisms. However, the extensive functional effects of those drugs remain essentially unexplored. We have undertaken a systematic comparative study of the three main treatments currently administered or proposed to progeria-affected children, namely, a farnesyltransferase inhibitor, the combination of an aminobisphosphonate and a statin (zoledronate and pravastatin), and the macrolide antibiotic rapamycin. This work was based on the assumption that mesodermal stem cells, which are derived from Hutchinson-Gilford progeria syndrome-induced pluripotent stem cells expressing major defects associated with the disease, may be instrumental to revealing such effects. Whereas all three treatments significantly improved misshapen cell nuclei typically associated with progeria, differences were observed in terms of functional improvement in prelamin A farnesylation, progerin expression, defective cell proliferation, premature osteogenic differentiation, and ATP production. Finally, we have evaluated the effect of the different drug combinations on this cellular model. This study revealed no additional benefit compared with single-drug treatments, whereas a cytostatic effect equivalent to that of a farnesyltransferase inhibitor alone was systematically observed. Altogether, these results reveal the complexity of the modes of action of different drugs, even when they have been selected on the basis of a similar mechanistic hypothesis, and underscore the use of induced pluripotent stem cell derivatives as a critical and powerful tool for standardized, comparative pharmacological studies.

  2. European Prospective Investigation into Cancer and Nutrition (EPIC): study populations and data collection

    DEFF Research Database (Denmark)

    Riboli, E.; Hunt, K.J.; Slimani, N.

    2002-01-01

    The European Prospective Investigation into Cancer and Nutrition (EPIC) is an ongoing multi-centre prospective cohort study designed to investigate the relationship between nutrition and cancer, with the potential for studying other diseases as well. The study currently includes 519 978...... participants (366 521 women and 153 457 men, mostly aged 35-70 years) in 23 centres located in 10 European countries, to be followed for cancer incidence and cause-specific mortality for several decades. At enrollment, which took place between 1992 and 2000 at each of the different centres, information...

  3. A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders.

    Science.gov (United States)

    Locci, Antonio Mario; Cincotti, Alberto; Todde, Sara; Orrù, Roberto; Cao, Giacomo

    2010-08-01

    A novel methodology is proposed for investigating the effect of the pulsed electric current during the spark plasma sintering (SPS) of electrically conductive powders without potential misinterpretation of experimental results. First, ensemble configurations (geometry, size and material of the powder sample, die, plunger and spacers) are identified where the electric current is forced to flow only through either the sample or the die, so that the sample is heated either through the Joule effect or by thermal conduction, respectively. These ensemble configurations are selected using a recently proposed mathematical model of an SPS apparatus, which, once suitably modified, makes it possible to carry out detailed electrical and thermal analysis. Next, SPS experiments are conducted using the ensemble configurations theoretically identified. Using aluminum powders as a case study, we find that the temporal profiles of sample shrinkage, which indicate densification behavior, as well as the final density of the sample are clearly different when the electric current flows only through the sample or through the die containing it, whereas the temperature cycle and mechanical load are the same in both cases.

  4. A methodology to investigate the intrinsic effect of the pulsed electric current during the spark plasma sintering of electrically conductive powders

    Directory of Open Access Journals (Sweden)

    Antonio Mario Locci, Alberto Cincotti, Sara Todde, Roberto Orrù and Giacomo Cao

    2010-01-01

    Full Text Available A novel methodology is proposed for investigating the effect of the pulsed electric current during the spark plasma sintering (SPS of electrically conductive powders without potential misinterpretation of experimental results. First, ensemble configurations (geometry, size and material of the powder sample, die, plunger and spacers are identified where the electric current is forced to flow only through either the sample or the die, so that the sample is heated either through the Joule effect or by thermal conduction, respectively. These ensemble configurations are selected using a recently proposed mathematical model of an SPS apparatus, which, once suitably modified, makes it possible to carry out detailed electrical and thermal analysis. Next, SPS experiments are conducted using the ensemble configurations theoretically identified. Using aluminum powders as a case study, we find that the temporal profiles of sample shrinkage, which indicate densification behavior, as well as the final density of the sample are clearly different when the electric current flows only through the sample or through the die containing it, whereas the temperature cycle and mechanical load are the same in both cases.

  5. MREIT experiments with 200μA injected currents: a feasibility study using two reconstruction algorithms, SMM and Harmonic BZ

    Science.gov (United States)

    Arpinar, V E; Hamamura, M J; Degirmenci, E; Muftuler, L T

    2012-01-01

    Magnetic resonance electrical impedance tomography (MREIT) is a technique that produces images of conductivity in tissues and phantoms. In this technique electrical currents are applied to an object and the resulting magnetic flux density is measured using magnetic resonance imaging (MRI) and the conductivity distribution is reconstructed using these MRI data. Currently the technique is used in research environments, primarily studying phantoms and animals. In order to translate MREIT to clinical applications, strict safety standards need to be established, especially for safe current limits. However, there are currently no standards for safe current limits specific to MREIT. Until such standards are established, human MREIT applications need to conform to existing electrical safety standards in medical instrumentation, such as the IEC601. This protocol limits patient auxiliary currents to 100μA for low frequencies. However, published MREIT studies have utilized currents 10 to 400 times larger than this limit, bringing into question whether the clinical applications of MREIT are attainable under current standards. In this study, we investigated the feasibility of MREIT to accurately reconstruct the relative conductivity of a simple agarose phantom using 200μA total injected current and we tested the performance of two MREIT reconstruction algorithms. These reconstruction algorithms used are the iterative sensitivity matrix method (SMM) by Ider and Birgul in 1998 with Tikhonov regularization and the Harmonic BZ proposed by Oh et al in 2003. The reconstruction techniques were tested at both 200μA and 5mA injected currents to investigate their noise sensitivity at low and high current conditions. It should be noted that 200μA total injected current into a cylindrical phantom generates only 14.7μA current in imaging slice. Similarly, 5mA total injected current results in 367μA in imaging slice. Total acquisition time for 200μA and 5mA experiments were about one

  6. Numerical and experimental investigation on the performance of three newly designed 100 kW-class tidal current turbines

    Directory of Open Access Journals (Sweden)

    Museok Song

    2012-09-01

    Full Text Available Three types of 100 kW-class tidal stream turbines are proposed and their performance is studied both numerically and experimentally. Following a wind turbine design procedure, a base blade is derived and two additional blades are newly designed focusing more on efficiency and cavitation. For the three designed turbines, a CFD is performed by using FLUENT. The calculations predict that the newly designed turbines perform better than the base turbine and the tip vortex can be reduced with additional efficiency increase by adopting a tip rake. The performance of the turbines is tested in a towing tank with 700 mm models. The scale problem is carefully investigated and the measurements are compared with the CFD results. All the prediction from the CFD is supported by the model experiment with some quantitative discrepancy. The maximum efficiencies are 0.49 (CFD and 0.45 (experiment at TSR 5.17 for the turbine with a tip rake.

  7. Investigation of the Influence of Magnetospheric Sources of Field-Aligned Currents on the Equatorial Electric Fields

    Science.gov (United States)

    Beloushko, Konstantin; Knyazeva, Mariya

    The urgency of studying electrodynamic processes related to the influence of spatial and temporal heterogeneities of the electromagnetic field in the Earth's upper atmosphere to the functioning of modern technological systems , satellite navigation systems , radio propagation Fundamentally new is the use of various third-party electrodynamic models in the total open loop model of the atmosphere based on the Upper Atmosphere Model (UAM) [1,2]. Performing calculations on model UAM using different spatial and temporal distributions of field-aligned currents and brands Lukianova and Papitashvili. A comparison of model results with data Jicamarca Incoherent Scatter Radar (Peru). References begin{enumerate} Namgaladze A.A., Korenkov Yu.N., Klimenko V.V., Karpov I.V., Bessarab F.S., Surotkin V.A., Gluschenko T.A., Naumova N.M. Global model of the thermosphere-ionosphere-protonosphere system. Pure and Applied Geophysics. № 2/3, 127, 219-254, 1988. Namgaladze A.A., Martynenko O.V., Namgaladze A.N. Global model of the upper atmosphere with variable latitudinal steps of numerical integration, IUGG XXI General Assembly, Boulder, 1995, Abstracts, GAB41F-6, B150, 1995, and (in Russian) Geamagn. Aeron., 36, 89-95, 1996a.

  8. Structural investigation of direct current magnetron sputtered Ti/NiV/Ag layers on n{sup +}Si substrate

    Energy Technology Data Exchange (ETDEWEB)

    Resnik, D. [Laboratory of Microsensor Structures and Electronics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, Ljubljana 1000 (Slovenia)], E-mail: drago.resnik@fe.uni-lj.si; Kovac, J. [Jozef Stefan Institute, Jamova 36, Ljubljana 1000 (Slovenia); Vrtacnik, D.; Amon, S. [Laboratory of Microsensor Structures and Electronics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, Ljubljana 1000 (Slovenia)

    2008-09-01

    Direct current sputtered Ti/NiV/Ag thin film metallization scheme on n{sup +}Si substrate was studied to reveal the nature of interface structure and adhesion related mechanisms. Ti/NiV/Ag scheme is usually applied when solderable backside contact is required. When thermal annealing of this sputtered metallic stack is performed below 550 deg. C, delamination frequently occurs. By energy dispersive X-ray spectroscopy analysis the delaminating interface was found to be between Si and Ti layer. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) depth profile analyses through metallic stack/Si substrate on samples exhibiting poor adhesion showed that a very thin amorphous Ti-Si phase was grown at Ti/Si interface when annealed at 400 deg. C. The XPS analyses of peeled layer and the surface of remained Si substrate after adhesion failure show that the delamination occurs between Si-substrate and amorphous Ti-Si layer. No contamination at Ti/Si interface was found as a possible origin for adhesion degradation. AES depth profiling of samples having good adhesion and annealed at 550 deg. C, revealed the formation of Ti-silicide and Ni-silicide at metal layers/Si interface, which in combination with Ni-Ti compound formed above this interface promote the adhesion.

  9. Current Understandings of the Research-Practice Gap From the Viewpoint of Complementary Medicine Academics: A Mixed-Method Investigation.

    Science.gov (United States)

    Leach, Matthew J; Tucker, Basil

    Research plays an important role in advancing health and healthcare. However, much research evidence is not reflected in contemporary complementary and alternative medicine (CAM) practice. Understanding and addressing the reasons for this research-practice gap may have positive implications for quality of care. To shed light on the gap between research and CAM practice. Descriptive cross-sectional, mixed-method study. A total of 126 senior CAM academics across Australasia, Europe, UK, and North America. Participants completed a 30-item online survey and a semi-structured interview; both of which explored the research-practice gap in CAM. A total of 43 (34%) academics completed the survey, with 29 (67%) respondents undergoing an interview. There was general agreement among respondents that CAM research should be informed by practice, and practice informed by research; however, most agreed that this did not reflect the current situation. Translational issues were perceived to be the primary reason for the research-practice gap in CAM. Suggested strategies for closing the gap focussed mostly around improving CAM student/practitioner education and training, and researcher-practitioner engagement and collaboration. Study findings point toward the presence of a research-practice gap in CAM, with several factors likely to be instrumental in sustaining this gap. Attention now needs to focus on understanding the views of CAM clinicians on this issue. Insights gained from this research will help inform the development of a multi-modal strategy that will effectively target the barriers to change in order to bring CAM research and practice closer together. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Investigative study of standards for digital repositories and related services

    CERN Document Server

    Foulonneau, Muriel; Badolato, Anne-Marie

    2008-01-01

    This study is meant for institutional repository managers, service providers, repository software developers and generally, all players taking an active part in the creation of the digital repository infrastructure for e-research and e-learning. It reviews the current standards, protocols and applications in the domain of digital repositories. Special attention is being paid to the interoperability of repositories to enhance the exchange of data in repositories. It aims to stimulate discussion about these topics and supports initiatives for the integration of and, where needed, development of

  11. Investigation of Sustainable Energy Policy: Nairobi Case Study

    Science.gov (United States)

    Shengyuan, Y.; Habiyaremye, J. F. L.; Yingying, W.

    2017-07-01

    A plan for actively achieving green energy obligation is a strategic tool for policies that point forward the diminution of the fossil fuel consumption and greenhouse gas (GHG) in conformity with the Paris environment-friendly accords (COP21) and updates of other ecosystem agreements. To achieve the concrete implementation of the sustainable energy strategy (SES) and to accomplish its objectives, an investigation is a critical factor. SES investigation has to consider both the advancement of each particular action and its wide-ranging green effect, which necessitates multiple levels of improvement. In this study, a consolidated eco strategy for evaluating, monitoring and handling the SES via investigation and execution process is established. The city of Nairobi was used as one of the geographical positions to test the effectiveness of this approach and to investigate its robust and weak points. Specifically, benefit-cost analysis, reliability, peer review and general level of participation were renowned as vital tools for attaining a functional SES investigation and for then drafting successful energy guidelines. Some suggestions were put forward to highlight the research and execution methods and to draw a road map of how SES can be strategically placed into practice.

  12. Pacemaker Created in Human Ventricle by Depressing Inward-Rectifier K+ Current: A Simulation Study

    Science.gov (United States)

    Zhang, Yue; Li, Qince; Zhang, Henggui

    2016-01-01

    Cardiac conduction disorders are common diseases which cause slow heart rate and syncope. The best way to treat these diseases by now is to implant electronic pacemakers, which, yet, have many disadvantages, such as the limited battery life and infection. Biopacemaker has been expected to replace the electronic devices. Automatic ventricular myocytes (VMs) could show pacemaker activity, which was induced by depressing inward-rectifier K+ current (IK1). In this study, a 2D model of human biopacemaker was created from the ventricular endocardial myocytes. We examined the stability of the created biopacemaker and investigated its driving capability by finding the suitable size and spatial distribution of the pacemaker for robust pacing and driving the surrounding quiescent cardiomyocytes. Our results suggest that the rhythm of the pacemaker is similar to that of the single cell at final stable state. The driving force of the biopacemaker is closely related to the pattern of spatial distribution of the pacemaker. PMID:26998484

  13. Pacemaker Created in Human Ventricle by Depressing Inward-Rectifier K+ Current: A Simulation Study

    Directory of Open Access Journals (Sweden)

    Yue Zhang

    2016-01-01

    Full Text Available Cardiac conduction disorders are common diseases which cause slow heart rate and syncope. The best way to treat these diseases by now is to implant electronic pacemakers, which, yet, have many disadvantages, such as the limited battery life and infection. Biopacemaker has been expected to replace the electronic devices. Automatic ventricular myocytes (VMs could show pacemaker activity, which was induced by depressing inward-rectifier K+ current (IK1. In this study, a 2D model of human biopacemaker was created from the ventricular endocardial myocytes. We examined the stability of the created biopacemaker and investigated its driving capability by finding the suitable size and spatial distribution of the pacemaker for robust pacing and driving the surrounding quiescent cardiomyocytes. Our results suggest that the rhythm of the pacemaker is similar to that of the single cell at final stable state. The driving force of the biopacemaker is closely related to the pattern of spatial distribution of the pacemaker.

  14. An Investigation on the Current Status of the Operation Recovery Rooms in Yazd Hospitals in 2010-2011

    Directory of Open Access Journals (Sweden)

    MR Khajeh Aminian

    2012-08-01

    Full Text Available Introduction: The recovery ward is a vital unit to care patients awaking from anesthesia and is a standard requirement for the operating room. Recovery ward is located adjacent to the operation room and is easily accessible to trained and skilled individuals. The unit must have adequate equipment for surveillance and monitoring of patients and required medication should also be provided. Methods: This study is a cross-sectional conducted in one phase through referring to hospital facilities and equipment. Physical space, personnel and their skill levels and other factors that are involved in the care of patients in the recovery have been investigated. The instruments used in this study were a check list and observe sheet which were completed by the researchers. Data analysis was conducted by SPSS software. Results: The results showed that the standards of buildings and physical space in the researched areas were mostly nonstandard. Equipment standards were to some extent in line with the criteria set by American Association of Anesthesia. Besides, some equipment was blow standard levels. Personnel standards regarding the number of nurses toward the number of recovery beds did not meet the standard criteria in most of the cases. Conclusion: The research shows that building standards in most cases are not in line with mentioned references. Undertaking equipment standards in the hospital recovery wards needs reviewing and providing controlling equipment for preventing the complications of recovery phase of anesthesia in recovery wards.

  15. Study on the Sustainable Development Mechanism of Community Library:Investigation and Analysis Based on Current Shijiazhuang City Community Library%社区图书馆可持续发展机制研究--基于石家庄市社区图书馆现状的调查分析

    Institute of Scientific and Technical Information of China (English)

    李菊花; 张云清; 刘顺昌; 张军立; 刘竞

    2013-01-01

    On the basis of the actual visit and investigation , this paper analyzes the present situation of community li-brary construction of Shijiazhuang and the existing problems .In order to improve the sustainable development of Shijiazhuang community library construction , it is necessary to seize the development opportunity , to establish the system of interaction and co-construction between community libraries and the community residents , and the system of interaction and cooperation between community libraries and college libraries , to prefect the long-acting man-agement mechanism .%通过对石家庄市社区图书馆实地走访调查,分析了石家庄市社区图书馆建设现状和存在的问题。提出石家庄市社区图书馆建设应抓住机遇,建立其与社区居民互动共建、与高校图书馆互动合作制度,健全社区图书馆发展的长效机制,实现其可持续发展。

  16. Electrical resistivity tomography investigations on a paleoseismological trenching study

    Science.gov (United States)

    Berge, Meriç Aziz

    2014-10-01

    Two-dimensional electrical resistivity tomography (ERT) investigation was performed in a paleoseismological trenching study. Data acquisition strategies such as the selection of electrode configuration and electrode intervals of ERT application were investigated in this paper. The ERT results showed that the Wenner and Wenner-Schlumberger arrays yielded similar results for subsurface characteristics whereas the DD array provided slightly different results. The combined usage of these arrays produced satisfactory images of the subsurface resistivity distribution. In addition, the electrode spacing tests revealed that a suitable interpretation of subsurface geology can be obtained from a 5 m electrode interval. However, a suitable trenching location defined by successful 2D resistivity models was obtained for 1 m electrode spacing. Therefore, the comparison of the trench and ERT results was also possible. The results of trenching and ERT studies substantially support each other.

  17. A Meta-Analytic Investigation of Therapy Modality Outcomes for Sexually Abused Children and Adolescents: An Exploratory Study

    Science.gov (United States)

    Hetzel-Riggin, Melanie D.; Brausch, Amy M.; Montgomery, Brad S.

    2007-01-01

    Objective: The purpose of the current study was to investigate the independent effects of different treatment elements on a number of secondary problems related to childhood and adolescent sexual abuse, as well as investigate a number of different moderators of treatment effectiveness. Method: Twenty-eight studies that provided treatment outcome…

  18. The Investigation of Sudden Arrhythmic Death Syndrome (SADS – the current approach to family screening and the future role of genomics & stem cell technology

    Directory of Open Access Journals (Sweden)

    Vishal eVyas

    2013-09-01

    Full Text Available SADS is defined as sudden death under the age of 40 years old in the absence of structural heart disease. Family screening studies are able to identify a cause in up to 50% of cases-most commonly long QT syndrome, Brugada and early repolarisation syndrome, and catecholaminergic polymorphic ventricular tachycardia using standard clinical screening investigations including pharmacological challenge testing. These diagnoses may be supported by genetic testing which can aid cascade screening and may help guide management. In the current era it is possible to undertake molecular autopsy provided suitable samples of DNA can be obtained from the proband. With the evolution of rapid sequencing techniques it is possible to sequence the whole exome for candidate genes. This major advance offers the opportunity to identify novel causes of lethal arrhythmia but also poses the challenge of managing the volume of data generated and evaluating variants of unknown significance. The emergence of induced pluripotent stem cell technology could enable evaluation of the electrophysiological relevance of specific ion channel mutations in the proband or their relatives and will potentially enable screening of idiopathic ventricular fibrillation survivors combining genetic and electrophysiological studies in derived myocytes. This also could facilitate the assessment of personalised preventative pharmacological therapies. This review will evaluate the current screening strategies in SADS families, the role of molecular autopsy and genetic testing and the potential applications of molecular and cellular diagnostic strategies on the horizon.

  19. Investigation of heavy ions diffusion under the influence of current-driven mechanism and compositional waves in plasma

    CERN Document Server

    Urpin, Vadim

    2016-01-01

    We consider diffusion caused by a combined influence of the Hall effect and electric currents, and argue that such diffusion forms chemical inhomogeneities in plasma. The considered mechanism can be responsible for the formation of element spots in laboratory and astrophysical plasmas. Such current-driven diffusion can be accompanied by the propagation of a particular type of waves which have not been considered earlier. In these waves, the impurity number density oscillare alone and their frequency is determined by the electric currents and sort of impurity ions. These compositional waves exist if the magnetic pressure in plasma is much greater than the gas pressure. Such waves lead to local variations of chemical composition and, hence, can manifest themselves by variations of the emission in spectral lines.

  20. Investigation of the current population of Dendroctonus micans (Kugelann (Coleoptera: Curculionidae and colonization rate of Rhizophagus grandis Gyllenhal (Coleoptera: Monotomidae in spruce forests of Artvin

    Directory of Open Access Journals (Sweden)

    Hazan Alkan Akıncı

    2017-04-01

    Full Text Available In this study, current population of Dendroctonus micans (Kugelann (Coleoptera: Curculionidae, and colonization status of its specific predator Rhizophagus grandis Gyllenhal (Coleoptera: Monotomidae in spruce forests of Artvin were investigated. Field works were conducted in a total of 30 sampling plots and along 20 transects. Sampling plots were 30 × 10 m in size and transects 50 m long. Presently, D. micans has a “very low infestation” rate in Artvin spruce forests and D. micans infestation rate is 4.1 times lower than the early 2000s. The trees at the stands edges were attacked more than trees in stand closure. All the larval galleries of D. micans were colonized by R. grandis. R. grandis could colonize larval galleries of its prey even in endemic conditions.

  1. Investigation of the Effects of Facility Background Pressure on the Performance and Voltage-Current Characteristics of the High Voltage Hall Accelerator

    Science.gov (United States)

    Kamhawi, Hani; Huang, Wensheng; Haag, Thomas; Spektor, Rostislav

    2014-01-01

    The National Aeronautics and Space Administration (NASA) Science Mission Directorate In-Space Propulsion Technology office is sponsoring NASA Glenn Research Center to develop a 4 kW-class Hall thruster propulsion system for implementation in NASA science missions. A study was conducted to assess the impact of varying the facility background pressure on the High Voltage Hall Accelerator (HiVHAc) thruster performance and voltage-current characteristics. This present study evaluated the HiVHAc thruster performance in the lowest attainable background pressure condition at NASA GRC Vacuum Facility 5 to best simulate space-like conditions. Additional tests were performed at selected thruster operating conditions to investigate and elucidate the underlying physics that change during thruster operation at elevated facility background pressure. Tests were performed at background pressure conditions that are three and ten times higher than the lowest realized background pressure. Results indicated that the thruster discharge specific impulse and efficiency increased with elevated facility background pressure. The voltage-current profiles indicated a narrower stable operating region with increased background pressure. Experimental observations of the thruster operation indicated that increasing the facility background pressure shifted the ionization and acceleration zones upstream towards the thruster's anode. Future tests of the HiVHAc thruster are planned at background pressure conditions that are expected to be two to three times lower than what was achieved during this test campaign. These tests will not only assess the impact of reduced facility background pressure on thruster performance, voltage-current characteristics, and plume properties; but will also attempt to quantify the magnitude of the ionization and acceleration zones upstream shifting as a function of increased background pressure.

  2. Maintaining turbidity and current flow in laboratory aquarium studies, a case study using Sabellaria spinulosa

    DEFF Research Database (Denmark)

    Davies, Andrew J.; S. Last, Kim; Attard, Karl

    2009-01-01

    Many aquatic organisms rely on the suspension of particulate matter for food or for building materials, yet these conditions are difficult to replicate in laboratory mesocosms. Consequently, husbandry and experimental conditions may often be sub-optimal. The Vortex Resuspension Tank (Vo......RT) is a simple and reliable system for the resuspension of food or sediments using an enclosed airlift. The particle rain from the lift is mixed in the tank by two water inputs that provide directional current flow across the study organism(s). The vortex mixing creates a turbulent lateral water flow that allows...... whereas under intermediate and high sediment rates there was consistent cumulative growth throughout a 15 d experiment. This highlights the importance of suspended sediment for S. spinulosa and also the suitability of the VoRT system for maintaining organisms with suspended matter requirements....

  3. Geohydrologic Investigations and Landscape Characteristics of Areas Contributing Water to Springs, the Current River, and Jacks Fork, Ozark National Scenic Riverways, Missouri

    Science.gov (United States)

    Mugel, Douglas N.; Richards, Joseph M.; Schumacher, John G.

    2009-01-01

    The Ozark National Scenic Riverways (ONSR) is a narrow corridor that stretches for approximately 134 miles along the Current River and Jacks Fork in southern Missouri. Most of the water flowing in the Current River and Jacks Fork is discharged to the rivers from springs within the ONSR, and most of the recharge area of these springs is outside the ONSR. This report describes geohydrologic investigations and landscape characteristics of areas contributing water to springs and the Current River and Jacks Fork in the ONSR. The potentiometric-surface map of the study area for 2000-07 shows that the groundwater divide extends beyond the surface-water divide in some places, notably along Logan Creek and the northeastern part of the study area, indicating interbasin transfer of groundwater between surface-water basins. A low hydraulic gradient occurs in much of the upland area west of the Current River associated with areas of high sinkhole density, which indicates the presence of a network of subsurface karst conduits. The results of a low base-flow seepage run indicate that most of the discharge in the Current River and Jacks Fork was from identified springs, and a smaller amount was from tributaries whose discharge probably originated as spring discharge, or from springs or diffuse groundwater discharge in the streambed. Results of a temperature profile conducted on an 85-mile reach of the Current River indicate that the lowest average temperatures were within or downstream from inflows of springs. A mass-balance on heat calculation of the discharge of Bass Rock Spring, a previously undescribed spring, resulted in an estimated discharge of 34.1 cubic feet per second (ft3/s), making it the sixth largest spring in the Current River Basin. The 13 springs in the study area for which recharge areas have been estimated accounted for 82 percent (867 ft3/s of 1,060 ft3/s) of the discharge of the Current River at Big Spring during the 2006 seepage run. Including discharge from

  4. Experimental study of the dependence of beam current on injection magnetic field in 6.4 GHz ECR ion source

    Indian Academy of Sciences (India)

    G S Taki; P R Sarma; D K Chakraborty; R K Bhandari; P K Ray

    2006-09-01

    The ion current from an electron cyclotron resonance (ECR) heavy ion source depends on the confining axial and radial magnetic fields. Some efforts were made by earlier workers to investigate magnetic field scaling on the performance of the ECR source. In order to study the dependence of the ion current on the injection magnetic field in the 6.4 GHz ECR source, we have measured the current by varying the peak injection field and have inferred that the variation of the current is exponential up to our maximum design injection field of 7.5 kG. An attempt has been made to understand this exponential nature on the basis of ion confinement time.

  5. An experimental investigation of the dynamics of submarine leveed channel initiation as sediment-laden density currents experience sudden unconfinement

    Energy Technology Data Exchange (ETDEWEB)

    Rowland, Joel C [Los Alamos National Laboratory; Hilley, George E [STANFORD UNIV; Fildani, Andrea [CHEVRON ETC

    2009-01-01

    Leveed submarine channels play a critical role in the transfer of sediment from the upper continental slopes to interslope basins and ultimately deepwater settings. Despite a reasonable understanding of how these channels grow once established, how such channels initiate on previously unchannelized portions of the seafloor remains poorly understood. We conducted a series of experiments that elucidate the influence of excess density relative to flow velocity on the dynamics of, and depositional morphologies arising from, density currents undergoing sudden unconfinement across a sloped bed. Experimental currents transported only suspended sediment across a non-erodible substrate. Under flow conditions ranging from supercritical to subcritical (bulk Richardson numbers of 0.02 to 1.2) our experiments failed to produce deposits resembling or exhibiting the potential to evolve into self-formed leveed channels. In the absence of excess density, a submerged sediment-laden flow produced sharp crested lateral deposits bounding the margins of the flow for approximately a distance of two outlet widths down basin. These lateral deposits terminated in a centerline deposit that greatly exceeded marginal deposits in thickness. As excess density increased relative to the outlet velocity, the rate of lateral spreading of the flow increased relative to the downstream propagation of the density current, transitioning from a narrow flow aligned with the channel outlet to a broad radially expanding flow. Coincident with these changes in flow dynamics, the bounding lateral deposits extended for shorter distances, had lower, more poorly defined crests that were increasingly wider in separation than the initial outlet, and progressively became more oblong rather than linear. Based on our results, we conclude that leveed channels cannot initiate from sediment-laden density currents under strictly depositional conditions. Partial confinement of these currents appears to be necessary to

  6. Application of Caco-2 Cell Line in Herb-Drug Interaction Studies: Current Approaches and Challenges

    Science.gov (United States)

    Awortwe, C.; Fasinu, P.S.; Rosenkranz, B.

    2015-01-01

    The Caco-2 model is employed in pre-clinical investigations to predict the likely gastrointestinal permeability of drugs because it expresses cytochrome P450 enzymes, transporters, microvilli and enterocytes of identical characteristics to the human small intestine. The FDA recommends this model as integral component of the Biopharmaceutics Classification System (BCS). Most dedicated laboratories use the Caco-2 cell line to screen new chemical entities through prediction of its solubility, bioavailability and the possibility of drug-drug or herb-drug interactions in the gut lumen. However, challenges in the inherent characteristics of Caco-2 cell and inter-laboratory protocol variations have resulted to generation of irreproducible data. These limitations affect the extrapolation of data from pre-clinical research to clinical studies involving drug-drug and herb-drug interactions. This review addresses some of these caveats and enumerates the plausible current and future approaches to reduce the anomalies associated with Caco-2 cell line investigations focusing on its application in herb-drug interactions. PMID:24735758

  7. Experimental Investigation on the Influence of Axial Magnetic Field Distribution on Resisting the Constriction of a High-Current Vacuum Arc

    Institute of Scientific and Technical Information of China (English)

    SHI Zongqian; LIU Zhigang; JIA Shenli; SONG Xiaochuan; WANG Lijun

    2009-01-01

    Effect of the axial magnetic field (AMF) on resisting the constriction of a high-current vacuum arc is studied in this paper. Two typical AMF distributions were investigated, i.e., the traditional bell-shaped AMF, and the saddle-shaped AMF. Experiments were conducted in a detachable vacuum chamber with a rms arc current in the range of 10 kA to 25 kA. The arc column was photographed by a high-speed digital camera with an exposure time of 2 microseconds. The constriction of the vacuum arc was compared by processing the images of the arc column under the two different field configurations and numerically determining the dimensions of the arc column near the electrodes. It was also confirmed that the AMF distribution had a signifcant influence on its effectiveness in resisting arc constriction, Furthermore, the AMF strength near the periphery of the arc is more influential than that at the centre of the electrodes in resisting arc constriction.

  8. Dynamic investigation of the transport current in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lucarelli, A; Frey, A; Yang, R; Luepke, G [Department of Applied Science, The College of William and Mary, Williamsburg, VA 23187-8795 (United States); Haugan, T J; Levin, G A; Barnes, P N [Air Force Research Laboratory, Wright-Patterson AFB, OH 45433-7919 (United States)

    2008-11-01

    The current density evolution in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} thin films is studied by time-resolved magneto-optical imaging as a function of the phase of an ac current applied simultaneously with a perpendicular dc magnetic field. We present a new empirical method to separate the total current distribution into a circulating current, which screens the applied field, and the applied transport current. The latter shows an asymmetric profile with pronounced peaks at the edges of the sample and its phase-dependent self-field is contained in the flux region bound by the circulating current. Threading dislocations provide the necessary pinning sites for the observed high local values of the transport current.

  9. Investigation of the Current Turn-off Characteristics of a GTO Thyristor in an Inductive Pulse Forming Network

    Science.gov (United States)

    2008-05-02

    pnp transistor (the top transistor in the figure) coupled to an npn transistor (the bottom transistor in the figure) such that the...collector of the pnp transistor connects to the base of the npn transistor and the collector of the npn transistor connects to the base of the pnp ... transistor . By design, a pnp P N P N N N N N N Cathode Anode Gate Base Unit Base Unit 12 transistor will conduct whenever current is

  10. The current status of usability studies of information technologies in China: a systematic study.

    Science.gov (United States)

    Lei, Jianbo; Xu, Lufei; Meng, Qun; Zhang, Jiajie; Gong, Yang

    2014-01-01

    To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Six hundred forty-seven publications were selected for analysis. We found that in China the literature on usability in the field of information technology began in 1994 and increased thereafter. The usability definitions from ISO 9241-11:1998 and Nielsen (1993) have been widely recognized and cited. Authors who have published several publications are rare. Fourteen journals have a publishing rate over 1%. Only nine publications about HIT were identified. China's usability research started relatively late. There is a lack of organized research teams and dedicated usability journals. High-impact theoretical studies are scarce. On the application side, no original and systematic research frameworks have been developed. The understanding and definition of usability is not well synchronized with international norms. Besides, usability research in HIT is rare. More human and material resources need to be invested in China's usability research, particularly in HIT.

  11. The Current Status of Usability Studies of Information Technologies in China: A Systematic Study

    Directory of Open Access Journals (Sweden)

    Jianbo Lei

    2014-01-01

    Full Text Available Objectives. To systematically review and analyze the current status and characteristics of usability studies in China in the field of information technology in general and in the field of healthcare in particular. Methods. We performed a quantitative literature analysis in three major Chinese academic databases and one English language database using Chinese search terms equivalent to the concept of usability. Results. Six hundred forty-seven publications were selected for analysis. We found that in China the literature on usability in the field of information technology began in 1994 and increased thereafter. The usability definitions from ISO 9241-11:1998 and Nielsen (1993 have been widely recognized and cited. Authors who have published several publications are rare. Fourteen journals have a publishing rate over 1%. Only nine publications about HIT were identified. Discussions. China’s usability research started relatively late. There is a lack of organized research teams and dedicated usability journals. High-impact theoretical studies are scarce. On the application side, no original and systematic research frameworks have been developed. The understanding and definition of usability is not well synchronized with international norms. Besides, usability research in HIT is rare. Conclusions. More human and material resources need to be invested in China’s usability research, particularly in HIT.

  12. Study of eddy current power loss in an RCS vacuum chamber

    Institute of Scientific and Technical Information of China (English)

    XU Shou-Yan; WANG Sheng

    2012-01-01

    In a Rapid Cycling Synchrotron (RCS),power loss due to an eddy current on the metal vacuum chamber would cause heating of the vacuum chamber.It is important to study the effect for estimating eddy current induced power loss and temperature growth.Analytical formulas for eddy current power loss for various types of vacuum chambers are derived for dipole and quadrupole repectively.By using the prototype of dipole of CSNS/RCS,an experiment was done to test the analytical formula.The derived formulas were applied to calculating the eddy current power loss on some special structures of an RCS vacuum chamber.

  13. Carbon Dioxide Sequestration by Direct Mineral Carbonation: Results from Recent Studies and Current Status

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, William K.; Dahlin, David C.; Nilsen, David N.; Rush, G.E.; Walters, Richard P.; Turner, Paul C.

    2001-01-01

    Direct mineral carbonation has been investigated as a process to convert gaseous CO2 into a geologically stable, solid final form. The process utilizes a solution of sodium bicarbonate (NaHCO3), sodium chloride (NaCl), and water, mixed with a mineral reactant, such as olivine (Mg2SiO4) or serpentine [Mg3Si2O5(OH)4]. Carbon dioxide is dissolved into this slurry, by diffusion through the surface and gas dispersion within the aqueous phase. The process includes dissolution of the mineral and precipitation of magnesium carbonate (MgCO3) in a single unit operation. Optimum results have been achieved using heat pretreated serpentine feed material, with a surface area of roughly 19 m2 per gram, and high partial pressure of CO2 (PCO2). Specific conditions include: 155?C; PCO2=185 atm; 15% solids. Under these conditions, 78% stoichiometric conversion of the silicate to the carbonate was achieved in 30 minutes. Studies suggest that the mineral dissolution rate is primarily surface controlled, while the carbonate precipitation rate is primarily dependent on the bicarbonate concentration of the slurry. Current studies include further examination of the reaction pathways, and an evaluation of the resource potential for the magnesium silicate reactant, particularly olivine. Additional studies include the examination of various pretreatment options, the development of a continuous flow reactor, and an evaluation of the economic feasibility of the process.

  14. The contribution of interindividual factors to variability of response in transcranial direct current stimulation studies

    Directory of Open Access Journals (Sweden)

    Lucia M Li

    2015-05-01

    Full Text Available There has been an explosion of research using transcranial direct current stimulation (tDCS for investigating and modulating human cognitive and motor function in healthy populations. It has also been used in many studies seeking to improve deficits in disease populations. With the slew of studies reporting ‘promising results’ for everything from motor recovery after stroke to boosting memory function, one could be easily seduced by the idea of tDCS being the next panacea for all neurological ills. However, huge variability exists in the reported effects of tDCS, with great variability in the effect sizes and even contradictory results reported. In this review, we consider the interindividual factors that may contribute to this variability. In particular, we discuss the importance of baseline neuronal state and features, anatomy, age and the inherent variability in the injured brain. We additionally consider how interindividual variability affects the results of motor evoked potential (MEP testing with transcranial magnetic stimulation (TMS, which, in turn, can lead to apparent variability in response to tDCS in motor studies.

  15. Study of the tunnelling initiated leakage current through the carbon nanotube embedded gate oxide in metal oxide semiconductor structures

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Gargi; Sarkar, C K [Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata (India); Lu, X B; Dai, J Y [Department of Applied Physics and Materials Research Center, Hong Kong Polytechnic University, Hong Kong (China)], E-mail: gargichakraborty0@yahoo.co.in, E-mail: phyhod@yahoo.co.in

    2008-06-25

    The tunnelling currents through the gate dielectric partly embedded with semiconducting single-wall carbon nanotubes in a silicon metal-oxide-semiconductor (MOS) structure have been investigated. The application of the gate voltage to such an MOS device results in the band bending at the interface of the partly embedded oxide dielectric and the surface of the silicon, initiating tunnelling through the gate oxide responsible for the gate leakage current whenever the thickness of the oxide is scaled. A model for silicon MOS structures, where carbon nanotubes are confined in a narrow layer embedded in the gate dielectric, is proposed to investigate the direct and the Fowler-Nordheim (FN) tunnelling currents of such systems. The idea of embedding such elements in the gate oxide is to assess the possibility for charge storage for memory device applications. Comparing the FN tunnelling onset voltage between the pure gate oxide and the gate oxide embedded with carbon nanotubes, it is found that the onset voltage decreases with the introduction of the nanotubes. The direct tunnelling current has also been studied at very low gate bias, for the thin oxide MOS structure which plays an important role in scaling down the MOS transistors. The FN tunnelling current has also been studied with varying nanotube diameter.

  16. Electrical transport properties of oligothiophene based molecular films studied by current sensing Atomic Force Microscopy

    NARCIS (Netherlands)

    Hendriksen, Bas L.M.; Martin, Florent; Qi, Yabing; Qi, Y.; Mauldin, Clayton; Vukmirovic, Nenad; Ren, JunFeng; Wormeester, Herbert; Katan, Allard J.; Altoe, Virginia; Aloni, Shaul; Frechet, Jean M.J.; Wang, Lin-Wang; Salmeron, Miquel

    2011-01-01

    Using conducting probe atomic force microscopy (CAFM) we have investigated the electrical conduction properties of monolayer films of a pentathiophene derivative on a SiO2/Si-p+ substrate. By a combination of current–voltage spectroscopy and current imaging we show that lateral charge transport

  17. A statistical study of the THEMIS satellite data for plasma sheet electrons carrying auroral upward field-aligned currents

    Science.gov (United States)

    Lee, S.; Shiokawa, K.; McFadden, J. P.

    2010-12-01

    The magnetospheric electron precipitation along the upward field-aligned currents without the potential difference causes diffuse aurora, and the magnetospheric electrons accelerated by a field-aligned potential difference cause the intense and bright type of aurora, namely discrete aurora. In this study, we are trying to find out when and where the aurora can be caused with or without electron acceleration. We statistically investigate electron density, temperature, thermal current, and conductivity in the plasma sheet using the data from the electrostatic analyzer (ESA) onboard the THEMIS-D satellite launched in 2007. According to Knight (Planet. Space Sci., 1973) and Lyons (JGR, 1980), the thermal current, jth(∝ nT^(1/2) where n is electron density and T is electron temperature in the plasma sheet), represents the upper limit to field aligned current that can be carried by magnetospheric electrons without field-aligned potential difference. The conductivity, K(∝ nT^(-1/2)), represents the efficiency of the upward field-aligned current (j) that the field-aligned potential difference (V) can produce (j=KV). Therefore, estimating jth and K in the plasma sheet is important in understanding the ability of plasma sheet electrons to carry the field-aligned current which is driven by various magnetospheric processes such as flow shear and azimuthal pressure gradient. Similar study was done by Shiokawa et al. (2000) based on the auroral electron data obtained by the DMSP satellites above the auroral oval and the AMPTE/IRM satellite in the near Earth plasma sheet at 10-18 Re on February-June 1985 and March-June 1986 during the solar minimum. The purpose of our study is to examine auroral electrons with pitch angle information inside 12 Re where Shiokawa et al. (2000) did not investigate well. For preliminary result, we found that in the dawn side inner magnetosphere (source of the region 2 current), electrons can make sufficient thermal current without field

  18. Microdialysis sampling for investigations of bioavailability and bioequivalence of topically administered drugs: current state and future perspectives

    DEFF Research Database (Denmark)

    Holmgaard, R; Nielsen, J B; Benfeldt, E

    2010-01-01

    by skin disease or barrier perturbation. A comparison between MD and other tissue sampling techniques reveals the advantages and limitations of the method. Subsequently, an in-depth discussion of the application of MD for the evaluation of bioavailability and bioequivalence of topical formulations...... is concluded by the current regulatory point of view. The future perspective includes further expansion and validation of the use of MD in the experimental and clinical setting as well as in the optimization of the method for regulatory purposes, i.e. the commercialization of bioequivalent, generic drug...

  19. The Study Of Low-Frequency Instabilities Of Current Sheaths Of Space Plasma Within The Quasi-Linear Theory

    Science.gov (United States)

    Lyahov, Vladimir; Neshchadim, Vladimir

    2015-04-01

    Investigation of the stability nonelectroneutral current sheets in the linear approximation [1-4] gives information only on the initial stage of development of perturbations when their amplitudes are small. Within the framework of the quasi-linear theory one can give an answer to the question of how long the initial perturbations can grow and how change the equilibrium state of the plasma current sheet under the reverse effect of these perturbations. We derive a system of nonlinear kinetic equation with self-consistent electromagnetic field in order to study the evolution of the distribution function of the background plasma current sheet in the approximation of low-frequency eigenmodes of instabilities. Evolution equation was obtained for the perturbation of the electromagnetic field and the instability growth rate in the current sheet. Algorithms were tested for solutions of the equations obtained. 1. Lyahov V.V., Neshchadim V.M. Kinetic theory of the current sheath. I. On polarization of an equilibrium current sheath// Advances in Space Research. -2012. -Vol. 50. -P. 318-326. 2. Lyahov V.V., Neshchadim V.M. Kinetic theory of the current sheath. II. Effect of polarization on the stability of a current sheath.// Advances in Space Research.-2013. -Vol. 51. -P. 730-741. 3. Lyahov V.V., Neshchadim V.M. The Effect of Polarization on the Stability of Current Sheaths in Space Plasma // EGU General Assembly 2013, held 7-12 April, 2013 in Vienna, Austria, id. EGU2013-1379, 04/2013, Bibliographic Code: 2013EGUGA..15.1379L 4. Lyahov V.V., Neshchadim V.M. About the eguilibrium and stability of nonelectroneutral current sheats // Advances in Space Research.-2014. -Vol. 54. -P. 901-907.

  20. Experimental study of yttrium barium copper oxide superconducting tape’s critical current under twisting moment

    Indian Academy of Sciences (India)

    Ziauddin Khan; Ananya Kundu; Subrata Pradhan

    2013-10-01

    Critical current (c) characteristics of 2G YBCO superconducting tape under the influence of twisting moment was experimentally investigated at varying current ramp rates in the self-field. Under a uniform twist, the degradation in the current-carrying capacity of YBCO tape up to 30% was observed at 77 K. The degradation is largely attributed to the shear stress and torsional shear strain resulting from the twisting. The superconductor to resistive transition index, , is also found to behave in an identical manner with increase in the twisting. Finite element analysis (FEA) of the tape in the experimental configuration with twisting moment being applied on to it has been carried out in COMSOL. The torsional strain calculated analytically as per the experimental configuration matches closely with that of FEA results, which shows that the critical current degradation is a function of strain.

  1. The investigation of the effectiveness of the criteria for the construction of a physics text for students with dyslexia: The case of the electric current

    Directory of Open Access Journals (Sweden)

    Panagiotis Papalexopoulos

    2008-01-01

    Full Text Available In this paper we studied the effectiveness of the writing criteria that are proposed to be applied during the construction of physics texts so that students with dyslexia do not confront reading difficulties with them. The effectiveness of the criteria has been assessed by the accomplishment of an investigation among students with and without dyslexia. A physics text that was constructed according to the writing criteria and referred to the concept of the electric current was given to read by all students. Twenty two (22 questions were used in order to assign the recognition of the physical phenomena, the physical quantities, the relations between the physical quantities and the units of measurement by all the students. The results of the investigation showed that the writing criteria helped the students with dyslexia not to have difficulties with the physics text about the “electric current”. The only area that students with dyslexia had some difficulties compared to the students without dyslexia was the recognition of the units of measurement.

  2. An Investigation of Carbon-Doping-Induced Current Collapse in GaN-on-Si High Electron Mobility Transistors

    Directory of Open Access Journals (Sweden)

    An-Jye Tzou

    2016-06-01

    Full Text Available This paper reports the successful fabrication of a GaN-on-Si high electron mobility transistor (HEMT with a 1702 V breakdown voltage (BV and low current collapse. The strain and threading dislocation density were well-controlled by 100 pairs of AlN/GaN superlattice buffer layers. Relative to the carbon-doped GaN spacer layer, we grew the AlGaN back barrier layer at a high temperature, resulting in a low carbon-doping concentration. The high-bandgap AlGaN provided an effective barrier for blocking leakage from the channel to substrate, leading to a BV comparable to the ordinary carbon-doped GaN HEMTs. In addition, the AlGaN back barrier showed a low dispersion of transiently pulsed ID under substrate bias, implying that the buffer traps were effectively suppressed. Therefore, we obtained a low-dynamic on-resistance with this AlGaN back barrier. These two approaches of high BV with low current collapse improved the device performance, yielding a device that is reliable in power device applications.

  3. Demagnetization treatment of remanent composite microspheres studied by alternating current susceptibility measurements

    NARCIS (Netherlands)

    van Berkum, S.; Erné, B.H.

    2013-01-01

    The magnetic remanence of silica microspheres with a low concentration of embedded cobalt ferrite nanoparticles is studied after demagnetization and remagnetization treatments. When the microspheres are dispersed in a liquid, alternating current (AC) magnetic susceptibility spectra reveal a constant

  4. Investigation on mechanical properties of basalt composite fabrics (experiment study

    Directory of Open Access Journals (Sweden)

    Talebi Mazraehshahi H.

    2010-06-01

    Full Text Available To fully appreciate the role and application of composite materials to structures, correct understanding of mechanical behaviors required for selection of optimum material. Fabric reinforced composites are composed of a matrix that is reinforced with pliable fabric, glass fabric is most popular reinforcement for different application specially in aircraft structure, although other fabric material are also used. At this study new fabric material called basalt with epoxy resin introduced and mechanical behaviors of this material investigated from view point of testing. For this study two type of fabric with different thickness used. Comparison between this composite reinforcement with popular reinforcement as carbon, glass, kevlar performed. To determine mechanical properties of epoxy based basalt fabric following test procedure performed : 1. Tensile testing according to ASTM D3039 in 0° and 90° direction to find ultimate strength in tension and shear, modulus of elasticity, elangation and ultimate strain. 2. Compression testing according to EN 2850 ultimate compression strength and maximum deformation under compression loading. 3. Shear testing according to ASTM D3518-94 to find in plane shear response of polymer matrix composites materials. 4. Predict flexural properties of sandwich construction which manufactured from basalt facing with PVC foam core according to ASTM C393-94. Material strength properties must be based on enough tests of material to meet the test procedure specifications [1]. For this reason six specimens were manufactured for testing and the tests were performed on them using an INSTRON machine model 5582. In the study, the effect of percent of resin in basalt reinforced composite was investigated. Also the weights of the ballast based composites with different percent of resin were measured with conventional composites. As the weight is an important parameter in aerospace industry when the designer wants to replace one

  5. NUMERICAL STUDY ON THE FORMATION OF THE SOUTH CHINA SEA WARM CURRENT I. BAROTROPIC CASE

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In this work, Princeton Ocean Model (POM) was used to study the formation of the South China Sea Warm Current (SCSWC) in the barotropic case. Monthly averaged wind stress and the inflow/outflow transports in January were used in the numerical simulation which reproduced the SCSWC. The effects of wind stress and inflow/outflow were studied separately. Numerical experiments showed that the Kuroshio intrusion through the Luzon Strait and the slope shelf in the northern SCS are necessary conditions for the formation of the SCSWC. In a flat bottom topography experiment, the wind stress driven northeast current in the northern SCS is a compensatory current.

  6. A status analysis of current digital marketing: a case study of Kauneusstudio FAB

    OpenAIRE

    Tran, Trong

    2015-01-01

    The subject of this thesis is a small company's current digital marketing status. This study was con-ducted in order for the owners of the beauty and hair salon Kauneusstudio FAB to improve their understanding of their customers’ behavior online and the significance of each digital channel they are using in the present marketing strategy. The goal of this study is to provide information for the company to recognize the strengths and the development points of the current digital marketing stra...

  7. Numerical study on short-circuit current of single layer organic solar cells with Schottkey contacts

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The influence of the cathode work function,carriers mobilities and temperature on the short-circuit current of single layer organic solar cells with Schottkey contacts was numerically studied,and the quantitative dependences of the short-circuit current on these quantities were obtained.The results provide the theoretical foundation for experimental study of single layer organic solar cells with Schottkey contacts.

  8. Synchronous Study of Ferroresonance and Inrush Current Phenomena and their Related Reasons in Ground Power Networks

    Science.gov (United States)

    Akrami, Amin; Ghaderi, Mohammad; Ghadi, Saeed

    2010-01-01

    Energizing the power transformers usually results in flowing very high inrush currents. This harmful current can be minimized using controlled switching and considering the value of residual flux. But nowadays, developing the ground power networks results in high increment of ferroresonance phenomenon occurrence due to the line' capacitance reactance and nonlinear inductive reactance of power transformer's core. In this study, these transient phenomena and their cause have studied synchronously.

  9. Study of Leakage Current Behaviour on Artificially Polluted Surface of Ceramic Insulator

    Institute of Scientific and Technical Information of China (English)

    B. Subba Reddy; G. R. Nagabhushana

    2003-01-01

    This paper presents the results of the study concerning to the leakage current be-haviour on artificially polluted ceramic insulator surface. From the present study it was observedthat there is a reasonably well-defined inception of current i.e. scintillations at a finite voltage.The corresponding voltages for extinction of the current are in the range of 0.8 kV to 2.1 kV.Obviously, the dry band formed in the immediate vicinity of the pin prevents smooth current flowas the voltage rises from zero. Only when the voltage is adequate it causes a flashover of the dryband and current starts flowing. As is common in similar current extinction phenomena, herealso, the extinction voltages are significantly lower than the inception voltages.Further, the voltage-current curves invariably show hysteresis - the leakage currents are lowerin the reducing portion of the voltage. This is obviously due to drying of the wet pollutantlayer thereby increasing its resistance. It is believed that this is the first time that such a directquantitative evidence of drying in individual half cycles is experimentally visualized.

  10. Effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies

    Science.gov (United States)

    Murase, Kenya; Nanjo, Takafumi; Satoshi, Ii; Miyazaki, Shohei; Hirata, Masaaki; Sugawara, Yoshifumi; Kudo, Masayuki; Sasaki, Kousuke; Mochizuki, Teruhito

    2005-11-01

    The purpose of this study was to investigate the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using multi-detector row CT (MDCT). Following the standard CT perfusion study protocol, continuous (cine) scans (1 s/rotation × 60 s) consisting of four 5 mm thick contiguous slices were performed using an MDCT scanner with a tube voltage of 80 kVp and a tube current of 200 mA. We generated the simulated images with tube currents of 50 mA, 100 mA and 150 mA by adding the corresponding noise to the raw scan data of the original image acquired above using a noise simulation tool. From the original and simulated images, we generated the functional images of cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) in seven patients with cerebrovascular disease, and compared the correlation coefficients (CCs) between the perfusion parameter values obtained from the original and simulated images. The coefficients of variation (CVs) in the white matter were also compared. The CC values deteriorated with decreasing tube current. There was a significant difference between 50 mA and 100 mA for all perfusion parameters. The CV values increased with decreasing tube current. There were significant differences between 50 mA and 100 mA and between 100 mA and 150 mA for CBF. For CBV and MTT, there was also a significant difference between 150 mA and 200 mA. This study will be useful for understanding the effect of x-ray tube current on the accuracy of cerebral perfusion parameters obtained by CT perfusion studies using MDCT, and for selecting the tube current.

  11. Switching performance and efficiency investigation of GaN based DC-DC Buck converter for low voltage and high current applications

    Science.gov (United States)

    Alatawi, Khaled; Almasoudi, Fahad; Matin, Mohammad

    2016-09-01

    The Wide band-gap (WBG) materials "such as Silicon Carbide (SiC) and Gallium nitride (GaN)" based power switching devices provide higher performance capabilities compared to Si-based power switching devices. The wide band-gap materials based power switching devices outperform Si-based devices in many performance characteristics such as: low witching loss, low conduction loss, high switching frequencies, and high operation temperature. GaN based switching devices benefit a lot of applications such as: future electric vehicles and solar power inverters. In this paper, a DC-DC Buck converter based on GaN FET for low voltage and high current applications is designed and investigated. The converter is designed for stepping down a voltage of 48V to 12V with high switching frequency. The capability of the GaN FET based buck converter is studied and compared to equivalent SiC MOSFET and Si-based MOSFET buck converters. The analysis of switching losses and efficiency was performed to compare the performance capabilities of GaN FET, SiC MOSFET and Si-based MOSFET. The results showed that the overall switching losses of GaN FET are lower than that of SiC and Si-based power switching devices. Also, the performance capability of GaN devices with higher frequencies is studied. GaN devices with high frequencies will reduce the total size and the cost of the power converter. In Addition, the overall efficiency of the DC-DC Buck converter is higher with the GaN FET switching devices, which make it more suitable for low voltage and high current applications.

  12. Motorcycle safety device investigation: A case study on airbags

    Indian Academy of Sciences (India)

    A Chawla; S Mukherjee

    2007-08-01

    The present standard for assessing the effectiveness of safety measures for motorcycle riders defined in ISO 13232 is unique and it incorporates evaluation by computer simulation supplemented by full-scale crash tests. This report describes the process of using FE (Finite Element) simulations to investigate safety options for motorcycle riders. The experience of developing finite element models acceptable as per ISO 13232 standards has been described. The variation in dummy head accelerations on impact with inflating airbags has been studied in an environment acceptable as per ISO 13232 standards. Based on the simulations, it may be concluded that inflating airbags in motorcycles do not pose a significant injury threat.

  13. Experimental study on directional solidification of Al-Si alloys under the influence of electric currents

    Science.gov (United States)

    Räbiger, D.; Zhang, Y.; Galindo, V.; Franke, S.; Willers, B.; Eckert, S.

    2016-07-01

    The application of electric currents during solidification can cause grain refinement in metallic alloys. However, the knowledge about the mechanisms underlying the decrease in grain size remains fragmentary. This study considers the solidification of Al-Si alloys under the influence of electric currents for the configuration of two parallel electrodes at the free surface. Solidification experiments were performed under the influence of both direct currents (DC) and rectangular electric current pulses (ECP). The interaction between the applied current and its own induced magnetic field causes a Lorentz force which produces an electro-vortex flow. Numerical simulations were conducted to calculate the Lorentz force, the Joule heating and the induced melt flow. The numerical predictions were confirmed by isothermal flow measurements in eutectic GaInSn. The results demonstrate that the grain refining effect observed in our experiments can be ascribed solely to the forced melt flow driven by the Lorentz force.

  14. Multiday Transcranial Direct Current Stimulation Causes Clinically Insignificant Changes in Childhood Dystonia: A Pilot Study.

    Science.gov (United States)

    Bhanpuri, Nasir H; Bertucco, Matteo; Young, Scott J; Lee, Annie A; Sanger, Terence D

    2015-10-01

    Abnormal motor cortex activity is common in dystonia. Cathodal transcranial direct current stimulation may alter cortical activity by decreasing excitability while anodal stimulation may increase motor learning. Previous results showed that a single session of cathodal transcranial direct current stimulation can improve symptoms in childhood dystonia. Here we performed a 5-day, sham-controlled, double-blind, crossover study, where we measured tracking and muscle overflow in a myocontrol-based task. We applied cathodal and anodal transcranial direct current stimulation (2 mA, 9 minutes per day). For cathodal transcranial direct current stimulation (7 participants), 3 subjects showed improvements whereas 2 showed worsening in overflow or tracking error. The effect size was small (about 1% of maximum voluntary contraction) and not clinically meaningful. For anodal transcranial direct current stimulation (6 participants), none showed improvement, whereas 5 showed worsening. Thus, multiday cathodal transcranial direct current stimulation reduced symptoms in some children but not to a clinically meaningful extent, whereas anodal transcranial direct current stimulation worsened symptoms. Our results do not support transcranial direct current stimulation as clinically viable for treating childhood dystonia.

  15. Electric field characteristics of electroconvulsive therapy with individualized current amplitude: a preclinical study.

    Science.gov (United States)

    Lee, Won Hee; Lisanby, Sarah H; Laine, Andrew F; Peterchev, Angel V

    2013-01-01

    This study examines the characteristics of the electric field induced in the brain by electroconvulsive therapy (ECT) with individualized current amplitude. The electric field induced by bilateral (BL), bifrontal (BF), right unilateral (RUL), and frontomedial (FM) ECT electrode configurations was computed in anatomically realistic finite element models of four nonhuman primates (NHPs). We generated maps of the electric field strength relative to an empirical neural activation threshold, and determined the stimulation strength and focality at fixed current amplitude and at individualized current amplitudes corresponding to seizure threshold (ST) measured in the anesthetized NHPs. The results show less variation in brain volume stimulated above threshold with individualized current amplitudes (16-36%) compared to fixed current amplitude (30-62%). Further, the stimulated brain volume at amplitude-titrated ST is substantially lower than that for ECT with conventional fixed current amplitudes. Thus individualizing the ECT stimulus current could compensate for individual anatomical variability and result in more focal and uniform electric field exposure across different subjects compared to the standard clinical practice of using high, fixed current for all patients.

  16. Investigation into in vitro anti-leishmanial combinations of calcium channel blockers and current anti-leishmanial drugs

    Directory of Open Access Journals (Sweden)

    Juliana Quero Reimão

    2011-12-01

    Full Text Available The need for drug combinations to treat visceral leishmaniasis (VL arose because of resistance to antimonials, the toxicity of current treatments and the length of the course of therapy. Calcium channel blockers (CCBs have shown anti-leishmanial activity; therefore their use in combination with standard drugs could provide new alternatives for the treatment of VL. In this work, in vitro isobolograms of Leishmania (Leishmania chagasi using promastigotes or intracellular amastigotes were utilised to identify the interactions between five CCBs and the standard drugs pentamidine, amphotericin B and glucantime. The drug interactions were assessed with a fixed ratio isobologram method and the fractional inhibitory concentrations (FICs, sum of FICs (ΣFICs and the overall mean ΣFIC were calculated for each combination. Graphical isobologram analysis showed that the combination of nimodipine and glucantime was the most promising in amastigotes with an overall mean ΣFIC value of 0.79. Interactions between CCBs and the anti-leishmanial drugs were classified as indifferent according to the overall mean ΣFIC and the isobologram graphic analysis.

  17. Forensic Polygraph in Crime Investigation: A Case Study

    Directory of Open Access Journals (Sweden)

    Aabad Ayoub

    2016-06-01

    Full Text Available A polygraph is an instrument that measures and records physiological changes inside the body. In the absence of a valid physical evidence, polygraphy may be a useful technique to verify truthfulness or detect deception. The present study was conducted to determine the truthfulness of a suspect in a murder case that was referred to PFSA for a polygraph examination. The stomach contents of the examinee and the hyoid bone of the vicvtim were submitted to the department of toxicology and forensic pathology at the PFSA, respectively. In the present study, integrated zone comparison technique (IZCT and forensic assessment interview technique (FAINT designed for specific and multi issue testing were used to examine the suspect. Computerized Academy for Scientific Investigative training (ASIT Algorithm and weighted scoring were applied in IZCT and FAINT scoring, respectively. The suspect of this murder case was brought to PFSA for polygraph examination. During the initial interview, the suspect denied any involvement in the said case. However, after complete polygraph examination, the suspect was proven to have been deceptive and later on confessed to police officials. The polygraph examination of the suspect proved him deceptive which was later confirmed by his confession. His stomach did not contain any toxic/ sedative material.

  18. Learning to Do Through Investigative Projects: A Case Study

    Science.gov (United States)

    Jolly, Pratibha

    2005-10-01

    In India, the likelihood of a girl student opting out of a physics course only because of gender issues is remote. Even though no special care is taken to attract women, a large percentage of the top-ranking students opt to major in physics. However, subtle forces operate in higher academia. The number of women in teaching and research institutes continues to be dismally low. The confidence and motivation of women students shows a distinct attenuation at the tertiary level. Inasmuch as the undergraduate years lay the foundation for a career in physics, there is a critical need to create learning experiences for women students that would enhance their motivation, nurture talent, and generate confidence in their capacity to make a creative contribution. The author has spent several years teaching at a women's college and in a university department with few women on the faculty. She has coordinated the Learning Through Investigative Projects program for undergraduate students of both genders. In a dual-pronged strategy, students are constructively engaged in open-ended investigative projects and assigned specific tasks. The touchstone of this program is the ambience in which the projects are carried out and the cognitive changes it effects in students as they are weaned away from the prevalent transmissionist mode of teaching and led to a constructivist paradigm of learning. They acquire an ability to work independently. The program and the underpinning pedagogic model have been very successful in capacity building and have influenced many students to choose careers in physics and academia. I present a case study of the work carried out under Project Science Online, in which students helped develop a microcomputer-based laboratory.

  19. Study of a Particle Based Films Cure Process by High-Frequency Eddy Current Spectroscopy

    Directory of Open Access Journals (Sweden)

    Iryna Patsora

    2016-12-01

    Full Text Available Particle-based films are today an important part of various designs and they are implemented in structures as conductive parts, i.e., conductive paste printing in the manufacture of Li-ion batteries, solar cells or resistive paste printing in IC. Recently, particle based films were also implemented in the 3D printing technique, and are particularly important for use in aircraft, wind power, and the automotive industry when incorporated onto the surface of composite structures for protection against damages caused by a lightning strike. A crucial issue for the lightning protection area is to realize films with high homogeneity of electrical resistance where an in-situ noninvasive method has to be elaborated for quality monitoring to avoid undesirable financial and time costs. In this work the drying process of particle based films was investigated by high-frequency eddy current (HFEC spectroscopy in order to work out an automated in-situ quality monitoring method with a focus on the electrical resistance of the films. Different types of particle based films deposited on dielectric and carbon fiber reinforced plastic substrates were investigated in the present study and results show that the HFEC method offers a good opportunity to monitor the overall drying process of particle based films. Based on that, an algorithm was developed, allowing prediction of the final electrical resistance of the particle based films throughout the drying process, and was successfully implemented in a prototype system based on the EddyCus® HFEC device platform presented in this work. This prototype is the first solution for a portable system allowing HFEC measurement on huge and uneven surfaces.

  20. Multimodal Study of Adult-Infant Interaction: A Review of Its Origins and Its Current Status

    Directory of Open Access Journals (Sweden)

    Soledad Carretero Pérez

    Full Text Available Abstract An interpretative review of research on adult-infant interactions involving the analysis of movement behaviors is presented, systematically linking previous studies to current research on the subject. Forty-two articles analyzing the dyad's interactive movement in the period 1970-2015 were found. Twelve papers were excluded, including only those that studied the phenomenon in the baby's first year of life. The results revealed that movement was a central topic in early interaction studies in the 70s. In the 1980's and 1990's, its study was marginal and it is currently resurging under the embodiment perspective. The conceptual framework and research methods used in the pioneering work are presented, and the thematic foci shared with current research are highlighted. Thus, essential keys are provided for the updated study of early interactions from a multimodal perspective.

  1. Transcranial Direct Current Stimulation and Power Spectral Parameters: a tDCS/EEG co-registration study

    Directory of Open Access Journals (Sweden)

    Anna Lisa Mangia

    2014-08-01

    Full Text Available Transcranial direct current stimulation (tDCS delivers low electric currents to the brain through the scalp. Constant electric currents induce shifts in neuronal membrane excitability, resulting in secondary changes in cortical activity. Concomitant electroencephalography (EEG monitoring during tDCS can provide valuable information on the tDCS mechanisms of action. This study examined the effects of anodal tDCS on spontaneous cortical activity in a resting brain to disclose possible modulation of spontaneous oscillatory brain activity. EEG activity was measured in ten healthy subjects during and after a session of anodal stimulation of the postero-parietal cortex to detect the tDCS-induced alterations. Changes in the theta, alpha, beta and gamma power bands were investigated. Three main findings emerged: 1 an increase in theta band activity during the first minutes of stimulation; 2 an increase in alpha and beta power during and after stimulation; 3 a widespread activation in several brain regions.

  2. Current Trends in the Studies of Allelochemicals for Their Application in Practice

    Directory of Open Access Journals (Sweden)

    Arsen V.Viter

    2015-06-01

    Full Text Available The allelochemicals have been largely used in agriculture, forestry, landscape design and ornamental plant growing for many decades. However, there is a lack of the comprehensive studies, where existing publications are analyzed and synthesized with regards to the theoretic aspects for such usage. The objective of this paper was to systemize the advances in the research on allelochemicals’ application in practice. Numerous novel methodological propositions have risen recently. We classified them into the physical, chemical, biological, biotechnological and cropgrowing approaches. The allelochemicals consist of the wide diversity of the substances according to their chemical nature. Among these substances we outlined, firstly, the unidentified plant exudates and the products of green manuring, secondly, the chemically characterized or purified substances, which include alcohols, organic acids, aliphatic compounds, aromatic, alicyclic and nitrogen-contain organic compounds. Several groups of the biotic sources of allelochemicals were described: dicotyledonous and monocotyledonous plants, particularly under their colonization by non-pathogenic strains of Fusarium oxysporum, marine flora and fungi, which exhibit the herbicidal activity. Different targets of the allelochemical application were listed in the paper and they were categorized into several groups: higher flora, animals, unicellular and multi-cellular fungi. We concluded that there is lack of the modern multifaceted knowledge bases for the information about the allelochemical application. Those knowledge bases must be useful in order to choose the appropriate biological method for solving each particular problem of plant cultivation. To that end we systemized the results of current investigation about the usage of allelochemicals in practice.

  3. Experimental Study on Vortex-Induced Vibrations of Submarine Pipeline near Seabed Boundary in Ocean Currents

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Unlike most previous studies on vortex-induced vibrations of a cylinder far from a boundary, this paper focuses on the influences of close proximity of a submarine pipeline to a rigid seabed boundary upon the dynamic responses of the pipeline in ocean currents. The effects of gap-to-diameter ratio and those of the stability parameter on the amplitude and frequency responses of a pipeline are investigated experimentally with a novel hydro-elastic facility. A comparison is made between the present experimental results of the amplitude and frequency responses for the pipes with seabed boundary effects and those for wall-free cylinders given by Govardhan and Williamson (2000) and Anand (1985). The comparison shows that the close proximity of a pipeline to seabed has much influence on the vortex-induced vibrations of the pipeline. Both the width of the lock-in ranges in terms of Vr and the dimensionless amplitude ratio Amax/D become larger with the decrease of the gap-to-diameter ratio e/D. Moreover, the vibration of the pipeline becomes easier to occur and its amplitude response becomes more intensive with the decrease of the stability parameter, while the pipeline frequency responses are affected slightly by the stability parameter.

  4. Safety and feasibility of transcranial direct current stimulation in pediatric hemiparesis: randomized controlled preliminary study.

    Science.gov (United States)

    Gillick, Bernadette T; Feyma, Tim; Menk, Jeremiah; Usset, Michelle; Vaith, Amy; Wood, Teddi Jean; Worthington, Rebecca; Krach, Linda E

    2015-03-01

    Transcranial direct current stimulation (tDCS) is a form of noninvasive brain stimulation that has shown improved adult stroke outcomes. Applying tDCS in children with congenital hemiparesis has not yet been explored. The primary objective of this study was to explore the safety and feasibility of single-session tDCS through an adverse events profile and symptom assessment within a double-blind, randomized placebo-controlled preliminary study in children with congenital hemiparesis. A secondary objective was to assess the stability of hand and cognitive function. A double-blind, randomized placebo-controlled pretest/posttest/follow-up study was conducted. The study was conducted in a university pediatric research laboratory. Thirteen children, ages 7 to 18 years, with congenital hemiparesis participated. Adverse events/safety assessment and hand function were measured. Participants were randomly assigned to either an intervention group or a control group, with safety and functional assessments at pretest, at posttest on the same day, and at a 1-week follow-up session. An intervention of 10 minutes of 0.7 mA tDCS was applied to bilateral primary motor cortices. The tDCS intervention was considered safe if there was no individual decline of 25% or group decline of 2 standard deviations for motor evoked potentials (MEPs) and behavioral data and no report of adverse events. No major adverse events were found, including no seizures. Two participants did not complete the study due to lack of MEP and discomfort. For the 11 participants who completed the study, group differences in MEPs and behavioral data did not exceed 2 standard deviations in those who received the tDCS (n=5) and those in the control group (n=6). The study was completed without the need for stopping per medical monitor and biostatisticial analysis. A limitation of the study was the small sample size, with data available for 11 participants. Based on the results of this study, tDCS appears to be safe

  5. Observational Study on Current Sheet of Magnetic Reconnection in Two Solar Eruptions

    Science.gov (United States)

    Qiang-wei, Cai; Ning, Wu; Jun, Lin

    2016-07-01

    The coronal magnetic configuration behind coronal mass ejections (CMEs) can commonly be stretched severely, thus to push the magnetic fields with opposite polarities to approach each other, and to form a current sheet of magnetic reconnection. The current sheet in solar eruptions is not only an important region to convert the magnetic free energy into thermal energy, plasma kinetic energy, and energetic particle beams, but also plays a role to connect CMEs and flares. In the CME events of 2003 January 3 and 2003 November 4, the development of current sheet has been observed in both cases. We have investigated the dynamic features and physical properties of current sheet in the two events, based on the data of LASCO (Large Angle and Spectrometric Coronagraph) and UVCS (Ultraviolet Coronagraph Spectrometer) on board of SOHO (Solar and Heliospheric Observatory), and the Hα data from BBSO (Big Bear Solar Observatory) and YNAO (Yunnan Astronomical Observatory). The existence of ions with a high degree of ionization, such as Fe+17 and Si+11, indicates a high temperature up to 3×106 ∼5×106 K in the region of current sheet. A direct measurement shows that the thickness of current sheet varies between 1.3×104 and 1.1×105 km, which increases first and then decreases with time. Using the CHIANTI code (v.7.1), we have further calculated the average values of electron temperature and corresponding emission measure (EM) respectively to be 3.86×106 K and 6.1×1024 cm-5 in the current sheet of the 2003 January 3 event. We also find that the current sheet twisted forth and back quasi-periodically during the eruption event on 2003 November 4 by analyzing the observational data from SOHO/UVCS.

  6. Langmuir probe study in the nonresonant current drive regime of helicon discharge

    Indian Academy of Sciences (India)

    Manash Kumar Paul; Dhiraj Bora

    2008-07-01

    Characterization of the current drive regime is done for helicon wave-generated plasma in a torus, at a very high operating frequency. A radiofrequency-compensated Langmuir probe is designed and used for the measurement of plasma parameters along with the electron energy distributions in radial scans of the plasma. The electron energy distribution patterns obtained in the operational regime suggest that Landau damping cannot be responsible for the efficient helicon discharge in the present study. A typical peaked radial density profile, high plasma temperature and absence of an appreciable amount of energetic electrons for resonant wave–particle interactions, suggest that the chosen operational regime is suitable for the study of nonresonant current drive by helicon wave. Successful and significant current drive achieved in our device clearly demonstrates the capability of nonresonant current drive by helicon waves in the present operational regime.

  7. Study on Catastrophic Air Current Early-warning and Control System of Coalmines

    Directory of Open Access Journals (Sweden)

    L.F. Fang

    2016-02-01

    Full Text Available Catastrophic air current significantly influences the stability of ventilation system, and existing studies have not considered the flow characteristics of catastrophic air current when designing the control systems. To analyze the effects of different kinds of coalmine accidents on safety production, grey relation entropy theory was used to analyze the hazard assessment of coalmine accidents. Fluent software was employed to study the flow characteristics of catastrophic air current, and the catastrophic air current early-warning and control system of coalmine was researched according to the theoretical analysis and numerical simulation. The threat of fire accidents and roof accidents were larger than other accidents. The influence of temperature and CO volume fraction distribution of fire accidents to the tailwind side was larger than that of the weather side, and gradient decreased on the weather side. This system can effectively control the spread of fire and poisonous gas,

  8. Looking for neuronal currents using MRI: an EEG-fMRI investigation of fast MR signal changes time-locked to frequent focal epileptic discharges.

    Science.gov (United States)

    Rodionov, Roman; Siniatchkin, Michael; Michel, Christoph M; Liston, Adam D; Thornton, Rachel; Guye, Maxime; Carmichael, David W; Lemieux, Louis

    2010-04-15

    Reproducible direct measurement of neuronal electrical activity using MRI signal changes due to local magnetic field perturbations would represent a step change in neuroimaging methods. While some previous studies using experiments based on evoked and spontaneous activity provided encouraging results no clear demonstration of neuronal current-related MR changes in the human brain has emerged to date. The availability of simultaneously acquired EEG-fMRI in patients with frequent interictal epileptic discharges (IED), which have significantly greater amplitude than evoked potentials, offers the opportunity to further investigate the phenomenon. We re-analysed simultaneously acquired EEG-fMRI data in 6 epilepsy patients with very frequent focal IED and a well-localised generator. A model of MRI signal changes due to fast activity and BOLD signal changes was used to identify fast MR signal changes, potentially directly reflecting neuronal activity. Simultaneously-acquired EEG allowed the comparison of electrical source localisation (ESI), clinical epilepsy localisation and BOLD signal changes with the fast MR signal changes. Clusters of IED-related fast MR signal change were observed in all cases. Spatial correspondence between the IED-related fast MR, BOLD, ESI clusters and irritative zone (IZ) was observed in one slice of a single dataset. The other IED-related fast MR clusters were remote from electro-clinically determined generators of interictal activity. The sign and magnitude of the fast MR signal changes varied across regions and subjects. The observed fast MR changes cannot be confidently attributed to the direct effect of neuronal currents due to lack of spatial concordance with generators of interictal activity, IED-related BOLD clusters and ESI estimates. Copyright 2009 Elsevier Inc. All rights reserved.

  9. Study on analysis technology of the leakage current from Power facilities by using the laser technology

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Bin; Lee, Bok Kyu; Ohk, Young Hwan [Korea Electric Power Corp. (KEPCO), Taejon (Korea, Republic of). Research Center; Han, Min Koo; Seung, Hwang Bo; Kwack, Hee Ro; Kim, Jae Chul [Electrical Engineering and Science Research Institute (Korea, Republic of)

    1995-12-31

    In order to apply the laser technology to the power systems, we widely investigated and analyzed optic fiber technology for signal transmissions, optic-sensor technology for detecting the physical quantum such as mechanical and electrical, and the base technology of laser application. The prototype was designed to detect the whole and the third harmonic current, for the analysis of the leakage current from gapless arrester. Also, the device was designed for portable use and for on-line checking. This prototype enables us to store and analyze the data easily by using the computer. Those stored data can be used as the reference data for estimating the extent of badness by analyzing and evaluating the trend of the leakage current with time. (author). 36 refs., 78 figs.

  10. Perspective of the study on the ring current - past, present and future

    Science.gov (United States)

    Ebihara, Y.

    2016-12-01

    The study of the ring current has a long history going back to the early 20th century. The ring current was predicted by Carl Stoermer to explain the equatorward movement of the auroral zone during magnetic storms. In 1917, Adolf Schmidt introduced the concept of the ring current to explain the global decrease of the geomagnetic field. Since then, number of studies have been accomplished in the context of the growth and recovery of magnetic storms. Observations have shown that protons and oxygen ions with energies 1 - 100 keV significantly increase during the storm main phase, which are most likely the major contributor to the storm-time ring current. When the loss of the ions dominates the injection of them, the storm recovery phase takes place. Immediate problems are the origin, transport and loss of the ions. All these relevant processes are essential to understand the growth and decay of the ring current. Derived problems, for example, include the entry of solar wind plasma into the magnetosphere, the outflow of ionospheric ions, generation of the convection electric field, influence of substorm-associated electric field, and pitch angle scattering of ions. Recalling that the ring current is the diamagnetic current, we shall consider the force balance and stress carefully. Generation of field-aligned currents is one of the consequences, which might redistribute the state of the inner magnetosphere including the plasmasphere, the ring current and the radiation belts. The ring current may also have a large influence on the geomagnetically induced current (GIC) on the ground at mid- and low-latitudes. The magnetic storms can be easily identified by looking at magnetograms, but the processes behind the magnetic storms cannot be easily understood because the processes depend on each other. From this sense, we shall pay much attention to the detailed function of each process as well as its role on the overall system. Dealing with the ring current as a complex system

  11. Theoretical study of the source-drain current and gate leakage current to understand the graphene field-effect transistors.

    Science.gov (United States)

    Yu, Cui; Liu, Hongmei; Ni, Wenbin; Gao, Nengyue; Zhao, Jianwei; Zhang, Haoli

    2011-02-28

    We designed acene molecules attached to two semi-infinite metallic electrodes to explore the source-drain current of graphene and the gate leakage current of the gate dielectric material in the field-effect transistors (FETs) device using the first-principles density functional theory combined with the non-equilibrium Green's function formalism. In the acene-based molecular junctions, we modify the connection position of the thiol group at one side, forming different electron transport routes. The electron transport routes besides the shortest one are defined as the cross channels. The simulation results indicate that electron transport through the cross channels is as efficient as that through the shortest one, since the conductance is weakly dependent on the distance. Thus, it is possible to connect the graphene with multiple leads, leading the graphene as a channel utilized in the graphene-based FETs in the mesoscopic system. When the conjugation of the cross channel is blocked, the junction conductance decreases dramatically. The differential conductance of the BA-1 is nearly 7 (54.57 μS) times as large as that of the BA-4 (7.35 μS) at zero bias. Therefore, the blocked graphene can be employed as the gate dielectric material in the top-gated graphene FET device, since the leakage current is small. The graphene-based field-effect transistors fabricated with a single layer of graphene as the channel and the blocked graphene as the gate dielectric material represent one way to overcome the problem of miniaturization which faces the new generation of transistors.

  12. Transcranial Direct Current Stimulation in Children and Adolescents With Attention-Deficit/Hyperactivity Disorder (ADHD): A Pilot Study.

    Science.gov (United States)

    Bandeira, Igor Dórea; Guimarães, Rachel Silvany Quadros; Jagersbacher, João Gabriel; Barretto, Thiago Lima; de Jesus-Silva, Jéssica Regina; Santos, Samantha Nunes; Argollo, Nayara; Lucena, Rita

    2016-06-01

    Studies investigating the possible benefits of transcranial direct current stimulation on left dorsolateral prefrontal cortex in children and adolescents with attention-deficit hyperactivity disorder (ADHD) have not been performed. This study assesses the effect of transcranial direct current stimulation in children and adolescents with ADHD on neuropsychological tests of visual attention, visual and verbal working memory, and inhibitory control. An auto-matched clinical trial was performed involving transcranial direct current stimulation in children and adolescents with ADHD, using SNAP-IV and subtests Vocabulary and Cubes of the Wechsler Intelligence Scale for Children III (WISC-III). Subjects were assessed before and after transcranial direct current stimulation sessions with the Digit Span subtest of the WISC-III, inhibitory control subtest of the NEPSY-II, Corsi cubes, and the Visual Attention Test (TAVIS-3). There were 9 individuals with ADHD according to Diagnostic and Statistical Manual of Mental Disorders (Fifth Edition) criteria. There was statistically significant difference in some aspects of TAVIS-3 tests and the inhibitory control subtest of NEPSY-II. Transcranial direct current stimulation can be related to a more efficient processing speed, improved detection of stimuli, and improved ability to switch between an ongoing activity and a new one.

  13. Using Critical Incidents of Instructional Design and Multimedia Production Activities to Investigate Instructional Designers' Current Practices and Roles

    Science.gov (United States)

    Sugar, William A.; Luterbach, Kenneth J.

    2016-01-01

    Through consideration of critical incidents, this study analyzed 106 effective, ineffective and extraordinary instructional design and multimedia production (MP) activities discussed by 36 instructional design professionals. This evaluation provided insights into these professionals' best and not so best practices during the past 6 months.…

  14. Investigating the Minimum Size of Study Area for an Activity-Based Travel Demand Forecasting Model

    Directory of Open Access Journals (Sweden)

    Qiong Bao

    2015-01-01

    Full Text Available Nowadays, considerable attention has been paid to the activity-based approach for transportation planning and forecasting by both researchers and practitioners. However, one of the practical limitations of applying most of the currently available activity-based models is their computation time, especially when large amount of population and detailed geographical unit level are taken into account. In this research, we investigated the possibility of restraining the size of the study area in order to reduce the computation time when applying an activity-based model, as it is often the case that only a small territory rather than the whole region is the focus of a specific study. By introducing an accuracy level of the model, we proposed in this research an iteration approach to determine the minimum size of the study area required for a target territory. In the application, we investigated the required minimum size of the study area surrounding each of the 327 municipalities in Flanders, Belgium, with regard to two different transport modes, that is, car as driver and public transport. Afterwards, a validation analysis and a case study were conducted. All the experiments were carried out by using the FEATHERS, an activity-based microsimulation modeling framework currently implemented for the Flanders region of Belgium.

  15. Investigation on Current Situation of Middle School Students’ Morning Exercise in Shantou City%汕头市中学生晨练现状调查研究

    Institute of Scientific and Technical Information of China (English)

    王腊姣; 卢刚

    2014-01-01

    This paper made an investigation and study of the current situation about students ’ morning exercise in 11 middle schools in Shantou city by means of questionnaire survey , comparative analysis and mathematical statis-tics, analyzed the secondary students ’ perspective, preference, ways, motivation, place and content, restrictive factors and common misconceptions of morning exercises , discussed the positive and negative factors for the devel-opment of students ’ morning exercises in secondary schools in Shantou , and finally proposed the corresponding countermeasure and suggestion .%本文通过问卷调查法、比较分析法及数理统计法等对汕头市11所学校的中学生晨练现状进行了调查研究,分析了中学生晨练的认知态度、情绪体验、组织形式、动机类型、晨练地点与内容、晨练的制约因素以及晨练中的常见误区,探讨了汕头市中学生晨练活动发展的积极因素和不利因素,并提出相应的有益于中学生晨练活动开展的对策和建议。

  16. Bowker, L. et al., eds. Unity in diversity? current trends in translation studies. Bowker, L. et al., eds. Unity in diversity? current trends in translation studies.

    Directory of Open Access Journals (Sweden)

    Maria Lúcia Vasconcellos

    2008-04-01

    Full Text Available Unity in Diversity? Current Trends in Translation Studies—a result of the diverse range of phenomena addressed in the Dublin City University Translation Studies (TS Conference (1996—proves to be a timely publication of St. Jerome Publishing at the end of the 20th century. This collection of papers exploring the central and uptodate issue of disciplinary identity in the young academic field of TS is in tune with the present concern in the area, as can be seen in the topic suggested for the international Translation Conference I IATIS Conference:“Disciplinary Identity—Redefining Translation in the 21st Century” (cf. www.iatis.org/content/korea/programme.php, to be held in 2005. Unity in Diversity? Current Trends in Translation Studies—a result of the diverse range of phenomena addressed in the Dublin City University Translation Studies (TS Conference (1996—proves to be a timely publication of St. Jerome Publishing at the end of the 20th century. This collection of papers exploring the central and uptodate issue of disciplinary identity in the young academic field of TS is in tune with the present concern in the area, as can be seen in the topic suggested for the international Translation Conference I IATIS Conference:“Disciplinary Identity—Redefining Translation in the 21st Century” (cf. www.iatis.org/content/korea/programme.php, to be held in 2005.

  17. Long Term Stability Investigation of Solid Oxide Electrolysis Cell with Infiltrated Porous YSZ Air Electrode Under High Current

    DEFF Research Database (Denmark)

    Veltzé, Sune; Ovtar, Simona; Simonsen, Søren Bredmose

    2015-01-01

    activity, due to high surface area of catalyst nano particles. Advantage of infiltration is also separate production of electrolyte backbone structure with good ionic connectivity and mechanical properties. With this study we present the results of a solid oxide cell with infiltrated porous yttria...... and the backbone, and perovskite catalyst material. Cobalt doped lanthanum nickelate was used as the perovskite catalyst due to its excellent performance. The cell was tested in steam electrolysis for at least 2000h. This initial test indicate that a stable air electrode was formed, and that the cell performance...

  18. Numerical study of magnetic reconnection process near in- terplanetary current sheet

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The third order accurate upwind compact difference scheme has been applied to the numerical study of the magnetic reconnection process possibly occurring near the interplanetary current sheet, under the framework of the two-dimensional compressible magnetohydrodynamics (MHD). Our results here show that the driven reconnection near the current sheet can occur within 10-30 min for the interplanetary high magnetic Reynolds number, RM =2 000-10 000, the stable magnetic reconnection structure can be formed in hour-order of magnitude, and there are some ba- sic properties such as the multiple X-line reconnections, vortical velocity structures, filament current systems, split-ting and collapse of the high-density plasma bulk. These results are helpful in understanding and identifying the magnetic reconnection phenomena near the interplanetary current sheets.

  19. 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.

  20. Semi-automatic determination of the Azores Current axis using satellite altimetry: Application to the study of the current variability during 1995-2006

    Science.gov (United States)

    Lázaro, C.; Juliano, M. F.; Fernandes, M. J.

    2013-06-01

    Satellite altimetry has been widely used to study the variability of the ocean currents such as the Azores Current (AzC) in the North Atlantic. Most analyses are performed over the region that encloses the current, thus being somehow affected by other oceanographic signals, e.g., eddies. In this study, a new approach for extracting the axis of a zonal current solely based on satellite altimetry is presented. This is a semi-automatic procedure that searches for the maximum values of the gradient of absolute dynamic topography (ADT), using the geostrophic velocity as auxiliary information. The advantage of this approach is to allow the analyses to be performed over a buffer centered on the current axis instead of using a wider region. It is here applied to the AzC for the period June 1995-October 2006.

  1. Investigation of tunneling current and local contact potential difference on the TiO2(110) surface by AFM/KPFM at 78 K

    Science.gov (United States)

    Wen, Huan Fei; Li, Yan Jun; Arima, Eiji; Naitoh, Yoshitaka; Sugawara, Yasuhiro; Xu, Rui; Hai Cheng, Zhi

    2017-03-01

    We propose a new multi-image method for obtaining the frequency shift, tunneling current and local contact potential difference (LCPD) on a TiO2(110) surface with atomic resolution. The tunneling current image reveals rarely observed surface oxygen atoms contrary to the conventional results. We analyze how the surface and subsurface defects affect the distribution of the LCPD. In addition, the subsurface defects are observed clearly in the tunneling current image, in contrast to a topographic image. To clarify the origin of the atomic contrast, we perform site-dependent spectroscopy as a function of the tip–sample distance. The multi-image method is expected to be widely used to investigate the charge transfer phenomena between the nanoparticles and surface sites, and it is useful for elucidating the mechanisms of catalytic reactions.

  2. Investigation of DC current models in Co2+ and Ti4+ substituted M-type BaCox Tix Fe(12-2x) O19 ferrite

    Science.gov (United States)

    Bhikhan, Vikas; Singh, Charanjeet; Kaur, Rajneesh; Jaroszewski, Maciej; Bindra Narang, S.

    2015-12-01

    The static current density ( J)-electric field ( E) characteristics of BaCo x Ti x Fe(12-2 x)O19 ferrite compositions ( x = 0.1, 0.3, 0.5, 0.7, 0.9) have been investigated at an applied field from 0.003 kV/m to 4.98 kV/m at room temperature. Compositions x = 0.3, 0.5 and 0.7 exhibit ohmic behavior at low applied field and non-linear conduction is observed in compositions x = 0.1, 0.3, 0.7 and 0.9 at higher applied field. The various non-linear conduction models, associated with Schottky, Poole-Frenkel, Ionic Hopping and Space Charge Limited Current mechanisms, have been discussed. The large current density has been found at higher substitution.

  3. The Return-Stroke of Lightning Current, Source of Electromagnetic Fields (Study, Analysis and Modelling

    Directory of Open Access Journals (Sweden)

    Dib Djalel

    2007-01-01

    Full Text Available In this study we present and analysis of the return-stroke lightning current and described their models which existing in the literature by several authors for the evaluation of radiated electromagnetic fields and modelling the coupling with electrical systems based on the calculation of induced voltages. the objective of this work was to take part in the improvement of the coordination of electric insulations and to put device also for calculation of the over-voltages induced in the electrical networks by the indirect lightning strokes which represent the most dangerous constraint and most frequent. A comparative study between the existing models and the analysis of the parameters which affect the space and temporal behaviour of the current lightning strokes as well as the importance of the lightning current at the channel base form the essential consequence of this study.

  4. Ranking current and prospective NO2 pollution mitigation strategies: An environmental and economic modelling investigation in Oxford Street, London.

    Science.gov (United States)

    Jeanjean, A P R; Gallagher, J; Monks, P S; Leigh, R J

    2017-03-21

    Air pollution continues to be a problem in the urban environment. A range of different pollutant mitigation strategies that promote dispersion and deposition exist, but there is little evidence with respect to their comparative performance from both an environmental and economic perspective. This paper focuses on examining different NO2 mitigation strategies such as trees, buildings facades coated with photocatalytic paint and solid barriers in Oxford Street in London. The case study findings will support ranking the environmental and economic impacts of these different strategies to improve personal exposure conditions on the footpath and on the road in a real urban street canyon. CFD simulations of airflow and NO2 dispersion in Oxford Street in London were undertaken using the OpenFOAM software platform with the k-ε model, taking into account local prevailing wind conditions. Trees are shown to be the most cost-effective strategy, with a small reduction in NO2 concentrations of up to 0.7% on the road. However, solid barriers with and without the application of photocatalytic paint and an innovative material (20 times more expensive than trees) can improve air quality on the footpaths more substantially, up to 7.4%, yet this has a significant detrimental impact on NO2 concentrations (≤23.8%) on the road. Photocatalytic paint on building surfaces presented a minimal environmental reductions (1.2%) and economic (>100 times more expensive than trees) mitigation strategy. The findings recognised the differences between footpath and road concentrations occurred and that a focused examination of three pollution hotspots can provide more cost effective pollution mitigation. This study considers how a number of pollutant mitigation measures can be applied in a single street canyon and demonstrates the strengths and weaknesses of these strategies from economic and environmental perspectives. Further research is required to extrapolate the findings presented here to

  5. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow; Experimentelle Untersuchung der Tropfenabscheidung einer horizontalen, entgegengerichteten Wasser/Luft-Schichtenstroemung

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Stephan Gerhard

    2015-07-01

    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

  6. Guest investigator program study: Physics of equatorial plasma bubbles

    Science.gov (United States)

    Tsunoda, Roland T.

    1994-01-01

    -shaped plasma bubbles. The second topic was pursued because the inability to predict the day-to-day occurrence of plasma bubbles indicated inadequate knowledge of the physics of plasma bubbles. An understanding of bubble formation requires an understanding of the roles of the various terms in the linearized growth rate of the collisional Rayleigh-Taylor instability. In our study, we examined electric-field perturbations found in SM-D EFI data and found that the seeding is more likely to be produced in the E region rather than the F region. The results of this investigation are presented in the Appendix of this report and will be submitted for publication in the Journal of Geophysical Research.

  7. Investigation of avalanche photodiodes radiation hardness for baryonic matter studies

    CERN Document Server

    Kushpil, V; Ladygin, V P; Kugler, A; Kushpil, S; Svoboda, O; Tlustý, P

    2015-01-01

    Modern avalanche photodiodes (APDs) with high gain are good device candidates for light readout from detectors applied in relativistic heavy ion collisions experiments. The results of the investigations of the APDs properties from Zecotek, Ketek and Hamamatsu manufacturers after irradiation using secondary neutrons from cyclotron facility U120M at NPI of ASCR in \\v{R}e\\v{z} are presented. The results of the investigations can be used for the design of the detectors for the experiments at NICA and FAIR.

  8. Investigation of field-dependent charge carrier generation and recombination in polymer based solar cells by transient extraction currents

    Energy Technology Data Exchange (ETDEWEB)

    Kniepert, Juliane; Blakesley, James; Neher, Dieter [University of Potsdam (Germany)

    2011-07-01

    There is an ongoing discussion as to whether photoinduced charge transfer in P3HT:PCBM solar cells leads to fully separated electrons and holes, independent of an electric field, or Coulombically bound interfacial charge pairs. While recent studies by R.A. Marsh et al. with transient absorption spectroscopy gave clear evidence for the formation and field-induced dissociation of bound polaron pairs, measurements by I.A. Howard et al. were in favour of hot exciton dissociation. Here, we present the results of bias-dependent Time Delayed Collection Field (TDCF) measurements to access directly the density of free charge carriers in P3HT:PCBM blends coated from dichlorobenzene. Solvent annealing was applied to yield a phase-separated morphology and the corresponding solar cells exhibit high values for the external quantum efficiency and fill factor. Our setup allowed us to follow the generation and recombination of photogenerated charges with a so far unattained time resolution of 40 ns. Our experiments show that the number of collected carriers is independent of the applied bias during pulsed illumination implying that extractable carriers in P3HT:PCBM blends are not generated by the field-assisted separation of bound polaron pairs. In addition, our experiments support the view that bimolecular recombination of free carriers is strongly suppressed in phase-separated P3HT:PBCM blends.

  9. Improving pharmacokinetic-pharmacodynamic modeling to investigate anti-infective chemotherapy with application to the current generation of antimalarial drugs.

    Directory of Open Access Journals (Sweden)

    Katherine Kay

    Full Text Available Mechanism-based pharmacokinetic-pharmacodynamic (PK/PD modelling is the standard computational technique for simulating drug treatment of infectious diseases with the potential to enhance our understanding of drug treatment outcomes, drug deployment strategies, and dosing regimens. Standard methodologies assume only a single drug is used, it acts only in its unconverted form, and that oral drugs are instantaneously absorbed across the gut wall to their site of action. For drugs with short half-lives, this absorption period accounts for a significant period of their time in the body. Treatment of infectious diseases often uses combination therapies, so we refined and substantially extended the PK/PD methodologies to incorporate (i time lags and drug concentration profiles resulting from absorption across the gut wall and, if required, conversion to another active form; (ii multiple drugs within a treatment combination; (iii differing modes of action of drugs in the combination: additive, synergistic, antagonistic; (iv drugs converted to an active metabolite with a similar mode of action. This methodology was applied to a case study of two first-line malaria treatments based on artemisinin combination therapies (ACTs, artemether-lumefantrine and artesunate-mefloquine where the likelihood of increased artemisinin tolerance/resistance has led to speculation on their continued long-term effectiveness. We note previous estimates of artemisinin kill rate were underestimated by a factor of seven, both the unconverted and converted form of the artemisinins kill parasites and the extended PK/PD methodology produced results consistent with field observations. The simulations predict that a potentially rapid decline in ACT effectiveness is likely to occur as artemisinin resistance spreads, emphasising the importance of containing the spread of artemisinin resistance before it results in widespread drug failure. We found that PK/PD data is generally very

  10. 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.

  11. 78 FR 23941 - Pilot Program for Early Feasibility Study Investigational Device Exemption Applications...

    Science.gov (United States)

    2013-04-23

    ... HUMAN SERVICES Food and Drug Administration Pilot Program for Early Feasibility Study Investigational... the Early Feasibility Study Investigational Device Exemption (IDE) Applications pilot program to May 8... ``Investigational Device Exemptions (IDE) for Early Feasibility Medical Device Clinical Studies, Including...

  12. Parametric study of variation in cargo-airplane performance related to progression from current to spanloader designs

    Science.gov (United States)

    Toll, T. A.

    1980-01-01

    A parametric analysis was made to investigate the relationship between current cargo airplanes and possible future designs that may differ greatly in both size and configuration. The method makes use of empirical scaling laws developed from statistical studies of data from current and advanced airplanes and, in addition, accounts for payload density, effects of span distributed load, and variations in tail area ratio. The method is believed to be particularly useful for exploratory studies of design and technology options for large airplanes. The analysis predicts somewhat more favorable variations of the ratios of payload to gross weight and block fuel to payload as the airplane size is increased than has been generally understood from interpretations of the cube-square law. In terms of these same ratios, large all wing (spanloader) designs show an advantage over wing-fuselage designs.

  13. Study of magnetic fields and current in the Z pinch at stagnation

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, V. V.; Anderson, A. A.; Astanovitskiy, A. L.; Nalajala, V.; Dmitriev, O. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); Papp, D. [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States); ELI-ALPS, ELI-Hu Nkft., H-6720 Szeged (Hungary)

    2015-09-15

    The structure of magnetic fields in wire-array Z pinches at stagnation was studied using a Faraday rotation diagnostic at the wavelength of 266 nm. The electron plasma density and the Faraday rotation angle in plasma were calculated from images of the three-channel polarimeter. The magnetic field was reconstructed with Abel transform, and the current was estimated using a simple model. Several shots with wire-array Z pinches at 0.5–1.5 MA were analyzed. The strength of the magnetic field measured in plasma of the stagnated pinch was in the range of 1–2 MG. The magnetic field and current profile in plasma near the neck on the pinch were reconstructed, and the size of the current-carrying plasma was estimated. It was found that current flowed in the large-size trailing plasma near the dense neck. Measurements of the magnetic field near the bulge on the pinch also showed current in trailing plasma. A distribution of current in the large-size trailing plasma can prevent the formation of multi-MG fields in the Z pinch.

  14. Experimental study of the velocity of density currents in convergent and divergent channels

    Institute of Scientific and Technical Information of China (English)

    Hasan Torabi POUDEH; Samad EMAMGHOLIZADEH; Manoocher Fathi-MOGHADAM

    2014-01-01

    The head velocity of the density current in the convergent and divergent channel is a key parameter for evaluating the extent to which suspended material travels, and for determining the type and distribution of sediment in the water body. This study experimentally evaluated the effects of the reach degree of convergence and divergence on the head velocity of the density current. Experiments were conducted in the flume with 6.0 m long, 0.72 m width and 0.6 m height. The head velocity was measured at three convergent degrees (-8o;-12o;-26o), at three divergent degrees (8o; 12o; 26o) and two slopes (0.009, 0.016) for various discharges. The measured head velocity of the density current is compared with the head velocity of the density current in the constant cross section channel. Based on non-dimensional and statistical analysis, relations as linear multiple regression are offered for predicting head velocity of the density current in the convergent, divergent and constant cross section channel. Also the results of this research show that for the same slope and discharge, the head velocity of the density current in the convergent and divergent channel are greater and less than the head velocity of the constant cross section, respectively.

  15. Empirical studies of magnetosheath and tail field and current structure, and model comparisons. Ph.D. Thesis

    Energy Technology Data Exchange (ETDEWEB)

    Kaymaz, Z.

    1993-12-31

    In this dissertation, the authors present the observational results obtained with IMP-8 in the magnetosheath and magnetotail, and compare them with the results from the gas dynamic (GD) and global magnetohydrodynamic (MHD) models. Although the magnetotail has been investigated by many others, the magnetosheath is one of the least studied regions of space despite its importance in solar wind-magnetosphere coupling. In this study, by utilizing a large magnetometer data set obtained simultaneously from IMP-8 and ISEE-3, the authors construct average magnetic field vector maps of the magnetosheath and tail in the cross-sectional plane. They determine how this average structure is influenced by the IMF, the Earth`s dipole tilt angle, and geomagnetic activity. For equatorial IMF`s, the magnetosheath field drapes asymmetrically around the magnetosphere causing a rotation of the field draping pattern, the tail current sheet twists, and plasma sheet field lines cease to show north-south symmetry. The magnetic field structure for north/south IMF`s is also shown to exhibit different properties including irregularities in the sheath (for southward) and placement of the dipolar and flaring regions in the tail. An IMF related perturbation field is observed in the tail which is strongest on the plasma sheet dawn and dusk sides for equatorial IMF, and on the flanks for north-south IMF. The Earth`s dipole tilt with respect to the geomagnetic equator affects the magnetotail current structure by causing its displacement from the geomagnetic equator. The authors examine the structure of the current sheet shape and location extensively using 16-years of IMP-8 magnetic field data. They show how geomagnetic activity affects this displacement. Many other field and current properties of the tail structure are also investigated such as the spatial distribution of the current density vectors and the (J x B) forces.

  16. Study of lower hybrid current drive efficiency and its correlation with photon temperatures in the HT-7 tokamak

    Science.gov (United States)

    Younis, J.; Wan, B. N.; Lin, S. Y.; Shi, Y. J.; Ding, B. J.; Gong, X.; HT-7 Team

    2009-07-01

    Lower hybrid current drive (LHCD) efficiency is a very important parameter. The experimental current drive efficiency is defined as η = IrfneR/PLH, where Irf is the current driven by the lower hybrid waves (LHWs), ne is the central line-average density, R is the major radius of the plasma and PLH is the injected LH wave power absorbed by the plasma through Landau damping. A study of current drive efficiency of LHWs in the HT-7 tokamak has been carried out in the parameter ranges: ne = (1.2-2.5) × 1019 m-3, Ip = (80-200) kA, Bt = 1.8 T, PLH = (188-532) kW in the limiter configuration. Current drive efficiency is investigated through a simple correlation with photon temperature and normalized intensity of fast electron bremstrahlung emission, which is, in the first approximation, proportional to the averaged velocity and population of the fast electrons. The plasma current scanning experiment shows that CD efficiency increase is due to the increase in both the photon temperature and the population of the fast electrons generated by LHWs. The density scanning experiment shows that as the plasma density is increased, an increment in CD efficiency along with the increase in the population of fast electrons is observed. The slowing down through the collisions with bulk electrons is mainly responsible for the decreased photon temperature during the plasma density scan. These experiments strongly suggest the dominant role of the population of fast electrons generated by LHCD and the generation of the current carried by fast electrons.

  17. An observational study of a shallow gravity current triggered by katabatic flow

    Directory of Open Access Journals (Sweden)

    A. Adachi

    2004-11-01

    Full Text Available Observations from a wind profiler and a meteorological tower are utilized to study the evolution of a gravity current that passed over the Meteorological Research Institute's (MRI field site in Tsukuba, Japan. The gravity current was created by katabatic flow originating on the mountainous slopes west of the field site. The passage of the shallow current was marked by a pronounced pressure disturbance and was accompanied by vertical circulations seen in the tower and profiler data. Direct vertical-beam measurements are difficult, especially at low heights during high-gradient events like density currents. In this study vertical velocities from the profiler are derived from the four oblique beams by use of the Minimizing the Variance of the Differences (MVD method. The vertical velocities derived from the MVD method agree well with in situ vertical velocities measured by a sonic anemometer on the tower.

    The gravity current is analyzed with surface observations, the wind profiler/RASS and tower-mounted instruments. Observations from the profiler/RASS and the tower-mounted instruments illustrate the structure of the gravity current in both wind and temperature fields. The profiler data reveal that there were three regions of waves in the vertical velocity field: lee-type waves, a solitary wave and Kelvin-Helmholtz waves. The lee-type waves in the head region of the gravity current seem to have been generated by the gravity current acting as an obstacle to prefrontal flow. The solitary wave was formed from the elevated head of the gravity current that separated from the feeder flow. Profiler vertical-motion observations resolve this wave and enable us to classify it as a Benjamin-Davis-Ono (BDO type solitary wave. The ducting mechanism that enabled the solitary wave to propagate is also revealed from the wind profiler/RASS measurements. The combination of high-resolution instruments at the MRI site allow us to

  18. Comparing snow models under current and future climates: Uncertainties and implications for hydrological impact studies

    Science.gov (United States)

    Troin, Magali; Poulin, Annie; Baraer, Michel; Brissette, François

    2016-09-01

    Projected climate change effects on snow hydrology are investigated for the 2041-2060 horizon following the SRES A2 emissions scenario over three snowmelt-dominated catchments in Quebec, Canada. A 16-member ensemble of eight snow models (SM) simulations, based on the high-resolution Canadian Regional Climate Model (CRCM-15 km) simulations driven by two realizations of the Canadian Global Climate Model (CGCM3), is established per catchment. This study aims to compare a range of SMs in their ability at simulating snow processes under current climate, and to evaluate how they affect the assessment of the climate change-induced snow impacts at the catchment scale. The variability of snowpack response caused by the use of different models within two different SM approaches (degree-day (DD) versus mixed degree-day/energy balance (DD/EB)) is also evaluated, as well as the uncertainty of natural climate variability. The simulations cover 1961-1990 in the present period and 2041-2060 in the future period. There is a general convergence in the ensemble spread of the climate change signals on snow water equivalent at the catchment scale, with an earlier peak and a decreased magnitude in all basins. The results of four snow indicators show that most of the uncertainty arises from natural climate variability (inter-member variability of the CRCM) followed by the snow model. Both the DD and DD/EB models provide comparable assessments of the impacts of climate change on snow hydrology at the catchment scale.

  19. Transcranial direct current stimulation to lessen neuropathic pain after spinal cord injury: a mechanistic PET study.

    Science.gov (United States)

    Yoon, Eun Jin; Kim, Yu Kyeong; Kim, Hye-Ri; Kim, Sang Eun; Lee, Youngjo; Shin, Hyung Ik

    2014-01-01

    It is suggested that transcranial direct current stimulation (tDCS) can produce lasting changes in corticospinal excitability and can potentially be used for the treatment of neuropathic pain. However, the detailed mechanisms underlying the effects of tDCS are unknown. We investigated the underlying neural mechanisms of tDCS for chronic pain relief using [(18)F]-fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET). Sixteen patients with neuropathic pain (mean age 44.1 ± 8.6 years, 4 females) due to traumatic spinal cord injury received sham or active anodal stimulation of the motor cortex using tDCS for 10 days (20 minutes, 2 mA, twice a day). The effect of tDCS on regional cerebral glucose metabolism was evaluated by [(18)F]FDG-PET before and after tDCS sessions. There was a significant decrease in the numeric rating scale scores for pain, from 7.6 ± 0.5 at baseline to 5.9 ± 1.8 after active tDCS (P = .016). We found increased metabolism in the medulla and decreased metabolism in the left dorsolateral prefrontal cortex after active tDCS treatment compared with the changes induced by sham tDCS. Additionally, an increase in metabolism after active tDCS was observed in the subgenual anterior cingulate cortex and insula. The results of this study suggest that anodal stimulation of the motor cortex using tDCS can modulate emotional and cognitive components of pain and normalize excessive attention to pain and pain-related information.

  20. Investigation of Students' Epistemological Beliefs and Attitudes towards Studying

    Science.gov (United States)

    Onen, Aysem Seda

    2011-01-01

    This study consists of the analysis on the relationship between the epistemological beliefs of secondary level students and their attitudes towards studying. The sampling of the study was formed by 440 students studying at Grade 10, 11 and 12 in secondary schools. The Epistemological Belief Questionnaire and the Attitudes towards Studying Scale,…

  1. A study on current situations of college students' foreign language anxiety

    Institute of Scientific and Technical Information of China (English)

    Bi Ran

    2015-01-01

    An empirical study on current situations of college students' foreign language anxiety is concerned with in this paper. The author adopted Horwitz's Foreign Language Classroom Anxiety Scale (FLCAS) to measure the level of foreign language anxiety of 325 participants and then the conclusions are drawn.

  2. A historical study to understand students’ current difficulties about RMS values

    Science.gov (United States)

    Khantine-Langlois, Françoise; Munier, Valérie

    2016-07-01

    Several studies show that students experience more and more difficulties managing the measurements of electrical values in alternating current and that they have trouble making links between theory and practice. They find it difficult to give meaning to root mean square (RMS; or effective) values, which are not understood as average values and are confused with instantaneous values. This shows that students do not clearly differentiate variable and direct currents. In this paper we try, with a historical study and a study of teaching the concept of RMS values, to understand students’ difficulties with this concept. In the first part we present an epistemological analysis of the concept of RMS values, showing that it is multifaceted and can be approached from different points of view. In the second part we analyse the evolution of French secondary school curricula and textbooks from the explicit introduction of variable currents to today, questioning the links between the evolution of the curricula and the evolution of the place of science and technology in our societies. We point out that the evolution of the curricula is linked to the social context and to the connections between science, technology and society, and also to the relationship with mathematics curricula. We show that alternating current is introduced earlier in the curriculum but has gradually lost all phenomenological description. This study allows us to better understand students’ difficulties and to discuss some implications for teaching.

  3. Understandings of Current Environmental Issues: Turkish Case Study in Six Teacher Education Colleges

    Science.gov (United States)

    Cakir, Mustafa; Irez, Serhat; Dogan, Ozgur Kivilcan

    2010-01-01

    The purpose of this study is to profile future science teachers' understandings of current environmental issues in the context of an education reform in Turkey. Knowledge base and understandings of elementary and secondary prospective science teachers about biodiversity, carbon cycle, global warming and ozone layer depletion were targeted in the…

  4. Study of multipass regimes in lower hybrid current drive experiments on Tore Supra

    Energy Technology Data Exchange (ETDEWEB)

    Arslanbekov, R.; Litaudon, X.; Peysson, Y.; Hoang, G.T.; Kazarian, F.; Moreau, D. [Association Euratom-CEA, Centre d`Etudes de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee; Shoucri, M.; Shkarofsky, I.P. [Centre Canadien de Fusion Magnetique, Varennes, PQ (Canada); Baranov, Y. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Kupfer, K. [General Atomics, San Diego, CA (United States)

    1995-12-31

    This document presents a study of multipass regimes in Lower Hybrid Current Drive on Tore Supra. A statistical model of the plasma wave propagation based on the Fokker-Planck theory is proposed, together with experimental results performed on Tore Supra. (TEC). 9 refs., 4 figs.

  5. Relevance of animal studies in regulatory toxicology : current approaches and future opportunities

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Feron, V.J.

    1996-01-01

    With rapidly increasing knowledge of toxicological processes, the scientific value and relevance of toxicity studies for risk assessment must be re-evaluated. In this paper, it is proposed that the rigid risk evaluation currently required should be replaced by a more flexible, case-by-case approach,

  6. Study of transient current induced by heavy-ion microbeams in Si and GaAs

    Energy Technology Data Exchange (ETDEWEB)

    Hirao, Toshio; Nashiyama, Isamu; Kamiya, Tomihiro; Suda, Tamotu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1997-03-01

    Heavy-ion microbeams were applied to the study of mechanism of single event upset (SEU). Transient current induced in p{sup +}n junction diodes by strike of heavy ion microbeam were measured by using a high-speed digitizing sampling system. (author)

  7. A Focus Group Study of Child Nutrition Professionals' Attitudes about Food Allergies and Current Training Practices

    Science.gov (United States)

    Lee, Yee Ming; Kwon, Junehee; Sauer, Kevin

    2014-01-01

    Purpose/Objectives: The purpose of this study was to explore child nutrition professionals' (CNPs) attitudes about food allergies, current practices of food allergy training, and operational issues related to food allergy training in school foodservice operations. Methods: Three focus groups were conducted with 21 CNPs with managerial…

  8. Field Study on the Effects of Waves and Currents on a Distributed Explosive Array

    Science.gov (United States)

    1993-12-01

    taken during each deployment. Table 1 Summary of Video Camera Resources Used During Study Camra ID [LoGato Formal Availabilty BWTEL Top of tower Black... usage . First, the offshore-flowing current would help extend the array seaward from the rocket anchors while reducing the longshore deformation

  9. Some Gaps in the Current Studies of Reading in Second/Foreign Language Learning

    Science.gov (United States)

    Fazeli, Seyed Hossein

    2010-01-01

    The ability to read written material is very important in the civilized world. In a society characterized by globalization and technological change, where knowledge is becoming increasingly important, reading ability is a key skill for active participation. The intent of the current study is to set out the nature of reading alongside express…

  10. Effects of weak transcranial Alternating Current Stimulation on brain activity – a review of known mechanisms from animal studies

    Directory of Open Access Journals (Sweden)

    Davide eReato

    2013-10-01

    Full Text Available Rhythmic neuronal activity is ubiquitous in the human brain. These rhythms originate from a variety of different network mechanisms, which give rise to a wide-ranging spectrum of oscillation frequencies. In the last few years an increasing number of clinical research studies have explored transcranial alternating current stimulation (tACS with weak current as a tool for affecting brain function. The premise of these interventions is that tACS will interact with ongoing brain oscillations. However, the exact mechanisms by which weak currents could affect neuronal oscillations at different frequency bands are not well known and this, in turn, limits the rational optimization of human experiments. Here we review the available in vitro and in vivo animal studies that attempt to provide mechanistic explanations. The findings can be summarized into a few generic principles, such as periodic modulation of excitability, shifts in spike timing, modulation of firing rate, and shifts in the balance of excitation and inhibition. These effects result from weak but simultaneous polarization of a large number of neurons. Whether this can lead to an entrainment or a modulation of brain oscillations, or whether AC currents have no effect at all, depends entirely on the specific dynamic that gives rise to the different brain rhythms, as discussed here for slow wave oscillations (~1 Hz and gamma oscillations (~30 Hz. We conclude with suggestions for further experiments to investigate the role of AC stimulation for other physiologically relevant brain rhythms.

  11. Investigating the health implications of social policy initiatives at the local level: study design and methods

    Directory of Open Access Journals (Sweden)

    Carey Gemma E

    2010-12-01

    Full Text Available Abstract Background In this paper we present the research design and methods of a study that seeks to capture local level responses to an Australian national social policy initiative, aimed at reducing inequalities in the social determinants of health. Methods/Design The study takes a policy-to-practice approach and combines policy and stakeholder interviewing with a comparative case study analysis of two not-for-profit organisations involved in the delivery of federal government policy. Discussion Before the health impacts of broad-scale policies, such as the one described in this study, can be assessed at the population level, we need to understand the implementation process. This is consistent with current thinking in political science and social policy, which has emphasised the importance of investigating how, and if, policies are translated into operational realities.

  12. A New Regime for Studying the High Bootstrap Current Fraction Plasma

    Institute of Scientific and Technical Information of China (English)

    A. Isayama; Y. Kamada; K. Ushigusa; T. Fujita; T. Suzuki; X. Gao

    2001-01-01

    A new experimental regime has recently been studied for achieving the high fraction of the bootstrap current in the JT-60U hydrogen discharges. The high poloidal beta(βp ~ 3.61) plasma was obtained by high-power neutral beam injection heating at a very high edge safety factor (Ip = 0.3 MA, Bt = 3.65 T, qeff = 25 - 35) region, and the bootstrap current fraction (fBS) was correspondingly about 40% using the ACCOME code calculation. It was observed that there were no magnetohydrodynamic instabilities to retard the increase of the βp and fBS parameters in the new regime.

  13. A Study of Strange Particles Produced in Neutrino Neutral Current Interactions in the NOMAD Experiment

    CERN Document Server

    Naumov, D V; Naumova, E; Popov, B; Astier, Pierre; Autiero, D; Baldisseri, Alberto; Baldo-Ceolin, Massimilla; Banner, M; Bassompierre, G; Benslama, K; Besson, N; Bird, I; Blumenfeld, B; Bobisut, F; Bouchez, J; Boyd, S; Bueno, A G; Bunyatov, S; Camilleri, L L; Cardini, A; Cattaneo, P W; Cavasinni, V; Cervera-Villanueva, A; Challis, R C; Collazuol, G; Conforto, G; Conta, C; Contalbrigo, M; Cousins, R; Daniels, D; Das, R; Degaudenzi, H M; Del Prete, T; De Santo, A; Dignan, T; Di Lella, L; do Couto e Silva, E; Dumarchez, J; Ellis, M; Feldman, G J; Ferrari, R; Ferrère, D; Flaminio, V; Fraternali, M; Gaillard, J M; Gangler, E; Geiser, A; Geppert, D; Gibin, D; Gninenko, S; Godley, A; Gómez-Cadenas, J J; Gosset, J; Gössling, C; Gouanère, M; Grant, A; Graziani, G; Guglielmi, A M; Hagner, C; Hernando, J; Hong, T M; Hubbard, D B; Hurst, P; Hyett, N; Iacopini, E; Joseph, C L; Juget, F R; Kent, N; Kirsanov, M; Klimov, O; Kokkonen, J; Kovzelev, A; Krasnoperov, A V; Lacaprara, S; Lachaud, C; Lakic, B; Lanza, A; La Rotonda, L; Laveder, M; Letessier-Selvon, A A; Lévy, J M; Linssen, Lucie; Ljubicic, A; Long, J; Lupi, A; Lyubushkin, V V; Marchionni, A; Martelli, F; Méchain, X; Mendiburu, J P; Meyer, J P; Mezzetto, Mauro; Mishra, S R; Moorhead, G F; Nédélec, P; Nefedov, Yu A; Nguyen-Mau, C; Orestano, D; Pastore, F; Peak, L S; Pennacchio, E; Pessard, H; Petti, R; Placci, A; Polesello, G; Pollmann, D; Polyarush, A Yu; Poulsen, C; Rebuffi, L; Rico, J; Roda, C; Rubbia, André; Salvatore, F; Schahmaneche, K; Schmidt, B; Schmidt, T; Sconza, A; Sevior, M E; Shih, D; Sillou, D; Soler, F J P; Sozzi, G; Steele, D; Stiegler, U; Stipcevic, M; Stolarczyk, T; Tareb-Reyes, M; Taylor, G N; Tereshchenko, V V; Toropin, A N; Touchard, A M; Tovey, Stuart N; Tran, M T; Tsesmelis, E; Ulrichs, J; Vacavant, L; Valdata-Nappi, M; Valuev, V Yu; Vannucci, François; Varvell, K E; Veltri, M; Vercesi, V; Vidal-Sitjes, G; Vieira, J M; Vinogradova, T G; Weber, F V; Weisse, T; Wilson, F F; Winton, L J; Yabsley, B D; Zaccone, Henri; Zuber, K; Zuccon, P

    2004-01-01

    Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles (K0s, Lambda, Lambda-bar) have been measured. Decays of resonances and heavy hyperons with an identified K0s or Lambda in the final state have been analyzed. Clear signals corresponding to K* and Sigma(1385) have been observed. First results on the measurements of the Lambda polarization in neutral current interactions have been obtained.

  14. A study of strange particles produced in neutrino neutral current interactions in the NOMAD experiment

    Science.gov (United States)

    Naumov, D.; Chukanov, A.; Naumova, E.; Popov, B.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Das, R.; Degaudenzi, H.; Del Prete, T.; de Santo, A.; Dignan, T.; di Lella, L.; Do Couto E Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrère, D.; Flaminio, V.; Fraternali, M.; Gaillard, J.-M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J.-J.; Gosset, J.; Gößling, C.; Gouanère, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hong, T. M.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Lacaprara, S.; Lachaud, C.; Lakić, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J.-M.; Linssen, L.; Ljubičić, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Méchain, X.; Mendiburu, J.-P.; Meyer, J.-P.; Mezzetto, M.; Mishra, S. R.; Moorhead, G. F.; Nédélec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, D.; Pastore, F.; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Sevior, M.; Shih, D.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipčević, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A.-M.; Tovey, S. N.; Tran, M.-T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J.-M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P.; NOMAD Collaboration

    2004-11-01

    Results of a detailed study of strange particle production in neutrino neutral current interactions are presented using the data from the NOMAD experiment. Integral yields of neutral strange particles ( Ks0, Λ, Λ¯) have been measured. Decays of resonances and heavy hyperons with an identified Ks0 or Λ in the final state have been analyzed. Clear signals corresponding to K and Σ(1385 have been observed. First results on the measurements of the Λ polarization in neutral current interactions have been obtained.

  15. Fast Food Pattern and Cardiometabolic Disorders: A Review of Current Studies

    OpenAIRE

    Zahra Bahadoran; Parvin Mirmiran; Fereidoun Azizi

    2016-01-01

    Background: There are growing concern globally regarding the alarming trend of fast food consump­tion and its related cardiometabolic outcomes including overweight and obesity. This study aimed to review the current evidences available in relation to adverse effects of fast food pattern on cardiometa­bolic risk factors. Methods: Relevant articles including epidemiological and clinical studies with appropriate design and good quality were obtained through searches of the Medline, PubMed, S...

  16. Transcranial direct current stimulation in the recovery of postural control after stroke : a pilot study

    OpenAIRE

    Saeys, Wim; Vereeck, Luc; Lafosse, Christophe; Truijen, Steven; Wuyts, Floris L.; de Heyning, van, P.H.

    2015-01-01

    Abstract: Purpose: This pilot study aimed to evaluate the effectiveness of multiple sessions of transcranial Direct Current Stimulation (tDCS) during 4 weeks on balance and gait parameters after stroke. Method: Thirty-one stroke patients were included in this randomised, double-blind, sham-controlled crossover study. The Tinetti test was used to assess functional balance and gait after stroke. Secondary measures, Rivermead Motor Assessment (RMA) and Trunk Impairment Scale (TIS), were register...

  17. Fast Food Pattern and Cardiometabolic Disorders: A Review of Current Studies

    OpenAIRE

    Zahra Bahadoran; Parvin Mirmiran; Fereidoun Azizi

    2015-01-01

    Background: There are growing concern globally regarding the alarming trend of fast food consump­tion and its related cardiometabolic outcomes including overweight and obesity. This study aimed to review the current evidences available in relation to adverse effects of fast food pattern on cardiometa­bolic risk factors. Methods: Relevant articles including epidemiological and clinical studies with appropriate design and good quality were obtained through searches of the Medline, PubMed, S...

  18. Computational and experimental studies of laser cutting of the current collectors for lithium-ion batteries

    Science.gov (United States)

    Lee, Dongkyoung; Patwa, Rahul; Herfurth, Hans; Mazumder, Jyotirmoy

    2012-07-01

    Sizing electrodes is an important step during Lithium-ion battery manufacturing processes since poor cut edge affects battery performance significantly and sometime leads to fire hazard. Mechanical cutting could result in a poor cut quality with defects. The cutting quality can be improved by using a laser, due to its high energy concentration, fast processing time, small heat-affected zone, and high precision. The cutting quality is highly influenced by operating parameters such as laser power and scanning speed. Thus, we studied a numerical simulation to provide a guideline for achieving clear edge quality. In order to simulate electrodes laser cutting for Lithium-Ion batteries, understanding the behavior of current collectors is crucial. This study focuses on current collectors, such as pure copper and aluminium. Numerical studies utilized a 3D self-consistent mathematical model for laser-material interaction. Observations of penetration time, depth, and threshold during laser cutting processes of current collectors are described. The model is validated experimentally by cutting current collectors and single side-coated electrodes with a single mode fiber laser. The copper laser cutting is laser intensity and interaction time dependent process. The aluminium laser cutting depends more on laser intensity than the interaction time. Numerical and experimental results show good agreement.

  19. Turbulent Gravity Current of Lock Release Type:A Numerical Study

    Institute of Scientific and Technical Information of China (English)

    G.Q.CHEN; J.H.W.LEE

    1999-01-01

    The time evolution of a turbulent gravity current of lock release type,formed by a finite volume of homogenous fluid released instantaneously into another fluid of slightly lower density,is studied numerically via the renormalization group(RNG)κ-ε model for Reynolds-stress closure to characterize the flow with transitional and highly localized turbulence,Consistent with previous experimental observations,the numerical results show that the gravity current passes through two distinct phases,an initial slumping phase in which the current head advances steadily,and a second self-similar phase in which the front velocity decreases like the negative third power of the time after release.An overall entrainment ratio proportional to the distance from the release point is found and comares well with available experimental data for the slumping phase.

  20. Novel study designs to investigate the placebo response

    OpenAIRE

    Klosterhalfen Sibylle; Enck Paul; Zipfel Stephan

    2011-01-01

    Abstract Background Investigating the size and mechanisms of the placebo response in clinical trials have relied on experimental procedures that simulate the double-blind randomized placebo-controlled design. However, as the conventional design is thought to elucidate drug rather than placebo actions, different methodological procedures are needed for the placebo response. Methods We reviewed the respective literature for trials designs that may be used to elucidate the size of the placebo re...

  1. The investigation of supply chain's reliability measure: a case study

    Science.gov (United States)

    Taghizadeh, Houshang; Hafezi, Ehsan

    2012-10-01

    In this paper, using supply chain operational reference, the reliability evaluation of available relationships in supply chain is investigated. For this purpose, in the first step, the chain under investigation is divided into several stages including first and second suppliers, initial and final customers, and the producing company. Based on the formed relationships between these stages, the supply chain system is then broken down into different subsystem parts. The formed relationships between the stages are based on the transportation of the orders between stages. Paying attention to the system elements' location, which can be in one of the five forms of series namely parallel, series/parallel, parallel/series, or their combinations, we determine the structure of relationships in the divided subsystems. According to reliability evaluation scales on the three levels of supply chain, the reliability of each chain is then calculated. Finally, using the formulas of calculating the reliability in combined systems, the reliability of each system and ultimately the whole system is investigated.

  2. Performance Investigation of Plate Type Heat Exchanger (A Case Study

    Directory of Open Access Journals (Sweden)

    Simarpreet Singh

    2014-04-01

    Full Text Available Heat exchanger is a thermodynamic system which is most commonly used in the process industry for exchanging heat energy between the fluids. flowing in the same or opposite direction. It is desired that effectiveness of heat exchanger should remain as large as possible. Heat exchanger's performance may be improved by the addition of fins or corrugations. These investigations include design of plate type heat exchanger, heat transfer enhancement, flow phenomenon and cleanliness factor. In process plants, this type of heat exchange is generally used for recovering heat content of exhaust steam. However, with the flow of fluid for a long period, fouling occurs on the plate surface. Therefore, it is required to investigate the effect of fouling, wherever the heat exchanger is installed. An extensive experimental investigation has been carried out under clean and dirty condition of the said plate type heat exchanger. Heat transfer and flow data were collected in experiment. From collected data heat transfer rate, overall heat transfer coefficient, fouling factor and cleanliness factor were evaluated. Based upon the cleanliness factor data, next date of cleanliness for plate type heat exchanger was predicted. It is felt that the outcome of the present research work may be quite useful for efficient operation of plate type heat exchanger installed in Process plants.

  3. RESULTS OF CALCULATION-EXPERIMENTAL INVESTIGATIONS OF ELECTRO-THERMAL RESISTIBILITY OF SHEET STEEL SAMPLES TO ACTION OF RATIONED COMPONENTS OF PULSED CURRENT OF ARTIFICIAL LIGHTING

    Directory of Open Access Journals (Sweden)

    M.I. Baranov

    2016-06-01

    Full Text Available Purpose. Calculation and experimental researches of the electro-thermal resistibility of the steel sheet samples to action standard pulse current components of the artificial lightning with amplitude-time parameters (ATP, corresponded the requirements of normative documents of USA for SAE ARP 5412 & SAE ARP 5416. Methodology. Electrophysics bases of technique of high tensions and large impulsive currents (LIC, and also scientific and technical bases of planning of devices of high-voltage impulsive technique and measuring in them LIC. Сurrent amplitude ImA=±200 kA (with a tolerance of ±10 %; current action integral JA=2∙106 A2•s (with a tolerance of ±20 %; time, corresponding to the amplitude of the current ImA, tmA≤50 microseconds; the duration of the current flow τpA≤500 microseconds. Results. The results of the evaluation of the calculated and experimental studies of electro-thermal resistance of the samples of plates measuring 0,5 m  0,5 m stainless steel 1 mm thickness to the action on them artificial lightning impulse currents with rationed ATP on the requirements of normative documents of USA for SAE ARP 5412 & SAE ARP 5416. A pulse A- component have a first amplitude 192 kA, the corresponding time of 34 μs, and the duration aperiodic component amplitude 804 A, corresponding to the time 9 ms. It has been shown that the long C- component current of artificial lightning can lead to keyhole these samples. The diameter of the holes in this thin steel sheet, which is formed during the flow of current C- components can reach 15 mm. The results of calculation and experiment agree within 28 %. Originality. For the first time in world practice on the generator large pulsed currents experimental studies of resistibility of sheet steel samples to the action of artificial lightning currents with critical parameters. Practical value. Using the results obtained in the practice of lightning protection will significantly improve the

  4. A case control study of premorbid and currently reported physical activity levels in chronic fatigue syndrome

    Directory of Open Access Journals (Sweden)

    Buchwald Dedra

    2006-11-01

    Full Text Available Abstract Background Patients with chronic fatigue syndrome typically report high levels of physical activity before becoming ill. Few studies have examined premorbid and current activity levels in chronically fatigued patients. Methods In a case-control study, 33 patients with chronic, unexplained, disabling fatigue attending a university-based clinic specializing in fatigue were compared to 33 healthy, age- and sex-matched controls. Patients rated their activity levels before their illness and currently, using scales designed for this purpose. Controls reported their level of activity of 2 years previously and currently. Chi-square analyses, Student's t tests, and Wilcoxon signed rank tests were used in pair matched analyses. Results Compared to healthy controls, patients with chronic, unexplained fatigue rated themselves as more active before their illness (p ≤ 0.001 and less active currently (p ≤ 0.001. The patients also reported they currently stood or walked less than the controls (median [inter-quartile range] = 4 2345 versus 9 [7.5–12] hours, p ≤ 0.001, and spent more time reclining (median [inter-quartile range] = 12 10111213141516 versus 8 [8–9.5] hours, p ≤ 0.001. These differences remained significant for the subset of patients who met strict criteria for chronic fatigue syndrome or fibromyalgia. Conclusion Patients with chronic, unexplained, disabling fatigue reported being more active before becoming ill than healthy controls. This finding could be explained by greater premorbid activity levels that could predispose to illness, or by an overestimation of previous activity. Either possibility could influence patients' perceptions of their current activity levels and their judgments of recovery. Perceived activity should be addressed as part of management of the illness.

  5. Investigation of Poultry Waste for Anaerobic Digestion: A Case Study

    Science.gov (United States)

    Salam, Christopher R.

    Anaerobic Digestion (AD) is a biological conversion technology which is being used to produce bioenergy all over the world. This energy is created from biological feedstocks, and can often use waste products from various food and agricultural processors. Biogas from AD can be used as a fuel for heating or for co-generation of electricity and heat and is a renewable substitute to using fossil fuels. Nutrient recycling and waste reduction are additional benefits, creating a final product that can be used as a fertilizer in addition to energy benefits. This project was conducted to investigate the viability of three turkey production wastes as AD feedstock: two turkey litters and a material separated from the turkey processing wastewater using dissolved air flotation (DAF) process. The DAF waste contained greases, oils and other non-commodity portions of the turkey. Using a variety of different process methods, types of bacteria, loading rates and food-to-microorganism ratios, optimal loading rates for the digestion of these three materials were obtained. In addition, the co-digestion of these materials revealed additional energy benefits. In this study, batch digestion tests were carried out to treat these three feedstocks, using mesophilic and thermophilic bacteria, using loading rates of 3 and 6 gVS/L They were tested separately and also as a mixture for co-digestion. The batch reactor used in this study had total and working volumes of 1130 mL and 500 mL, respectively. The initial organic loading was set to be 3 gVS/L, and the food to microorganism ratio was either 0.6 or 1.0 for different treatments based on the characteristics of each material. Only thermophilic (50 +/- 2ºC) temperatures were tested for the litter and DAF wastes in continuous digestion, but mesophilic and thermophilic batch digestion experiments were conducted. The optimum digestion time for all experiments was 14 days. The biogas yields of top litter, mixed litter, and DAF waste under

  6. Uloma Doris Onuoha Abstract This study investigated attitude to ...

    African Journals Online (AJOL)

    Uloma1

    Babcock University. The descriptive research approach was used for the study. ... between the level of study and attitude towards plagiarism. Based on the ... issues pertaining to plagiarism while students also endeavour to utilise Cloud and.

  7. Policy forum: studying eyewitness investigations in the field.

    Science.gov (United States)

    Schacter, Daniel L; Dawes, Robyn; Jacoby, Larry L; Kahneman, Daniel; Lempert, Richard; Roediger, Henry L; Rosenthal, Robert

    2008-02-01

    This article considers methodological issues arising from recent efforts to provide field tests of eyewitness identification procedures. We focus in particular on a field study (Mecklenburg 2006) that examined the "double blind, sequential" technique, and consider the implications of an acknowledged methodological confound in the study. We explain why the confound has severe consequences for assessing the real-world implications of this study.

  8. 埋地管道交流腐蚀的研究进展%INVESTIGATION PROGRESS OF ALTERNATING CURRENT CORROSION ON BURIED PIPELINES

    Institute of Scientific and Technical Information of China (English)

    董亮; 路民旭; 杜艳霞; 姜子涛

    2011-01-01

    Alternating current (AC) corrosion on buried pipelines has drawn much attention. Current status of the researches is reviewed in this article. The understanding of AC corrosion is mentioned. Characteristics, mechanisms, and mitigations of AC corrosion and the evaluation methods for AC corrosion risk are concluded. Finally, the issues for further investigations are proposed.%综述了埋地管道交流腐蚀的研究现状,包括人们对交流腐蚀的认识过程,交流腐蚀的特征和机理,交流腐蚀风险的评价方法以及交流腐蚀的缓解措施.最后提出了埋地管道交流腐蚀有待解决的问题.

  9. A Power Interruption Technique for Investigation of Temperature Difference in Stabilized Low Direct-Current Arc Burning in Pure Argon on Atmospheric Pressure

    Institute of Scientific and Technical Information of China (English)

    M. M. Kuzmanovi(c); J. J. Savovi(c); D. P. Rankovi(c); M. Stoiljkovi(c); A. Anti(c)-Jovanovi(c); M.S. Pavlovi(c); M. Marinkovi(c)

    2008-01-01

    @@ Plasma of argon stabilized arc column, in a current range 3-11 A, is investigated using emission spectrometric diagnostic techniques. Temperatures are evaluated using several methods: argon line to adjacent recombinational continuum intensity ratio, absolute emissivity of argon fine, measurement of electron number density, and power interruption. Electron number density is evaluated from absolute emissivity of recombinational continuum. The difference between electron Te and heavy particle Th temperature ranged from 4500 K for 3 A to 2300 K for 11 A arc current. By comparing the present with the previously obtained results, using the same arc device but with the introduction of water aerosol, it is concluded that water aerosol reduces the difference Te - Th and brings plasma closer to the partial thermodynamic equilibrium state.

  10. Current humanized mouse models for studying human immunology and HIV-1 immuno-pathogenesis

    Institute of Scientific and Technical Information of China (English)

    MEISSNER; Eric

    2010-01-01

    A robust animal model for "hypothesis-testing/mechanistic" research in human immunology and immuno-pathology should meet the following criteria.First,it has well-studied hemato-lymphoid organs and target cells similar to those of humans.Second,the human pathogens establish infection and lead to relevant diseases.Third,it is genetically inbred and can be manipulated via genetic,immunological and pharmacological means.Many human-tropic pathogens such as HIV-1 fail to infect murine cells due to the blocks at multiple steps of their life cycle.The mouse with a reconstituted human immune system and other human target organs is a good candidate.A number of human-mouse chimeric models with human immune cells have been developed in the past 20 years,but most with only limited success due to the selective engraftment of xeno-reactive human T cells in hu-PBL-SCID mice or the lack of significant human immune responses in the SCID-hu Thy/Liv mouse.This review summarizes the current understanding of HIV-1 immuno-pathogenesis in human patients and in SIV-infected primate models.It also reviews the recent progress in the development of humanized mouse models with a functional human immune system,especially the recent progress in the immunodeficient mice that carry a defective gammaC gene.NOD/SCID/gammaC-/(NOG or NSG) or the Rag2-/-/gammaC-/double knockout (DKO) mice,which lack NK as well as T and B cells (NTB-null mice),have been used to reconstitute a functional human immune system in central and peripheral lymphoid organs with human CD34+ HSC.These NTB-hu HSC humanized models have been used to investigate HIV-1 infection,immuno-pathogenesis and therapeutic interventions.Such models,with further improvements,will contribute to study human immunology,human-tropic pathogens as well as human stem cell biology in the tissue development and function in vivo.

  11. A Study and Brief Investigation on Invisibility Of Aircrafts (Vimanas

    Directory of Open Access Journals (Sweden)

    A.Hemant Kumar Yadav

    2015-01-01

    Full Text Available Making aircrafts invisible to human eye would be a great advantage in defence and military use. The Vedas show us evidence that the ancient ancestors have advanced technology to make a vimana invisible. They had great knowledge on the sun rays, and energies extraction which can create the invisibility for the vimana. The paper describes the various writings and investigation on the topics, comparing with the modern findings of solar rays usage which lead to the better understanding of Ancient advanced vimanas and provide a path to the findings of invisibility

  12. A Study on the Current Oil and Gas Price Formula and Its Improvement

    Energy Technology Data Exchange (ETDEWEB)

    Park, Chang Won; Lee, Young Koo [Korea Energy Economics Institute, Euiwang (Korea)

    2000-12-01

    The object of this study is to suggest some improvements on current price formulas on oil and gas which have been pivotal roles in the process of Korean economic growth. This study first examines basic frames and transition of oil and gas pricing in Korea and then finds some suggestions on them by scrutinizing their theoretical backgrounds. This study finds several problems on oil and gas pricing formulas. (a) In a model that is now studied to evaluate the current domestic oil price, the costs associated with oil security such as oil stockpile are fully penetrated into oil price without their fair evaluations. There is no evaluation principle on the costs occurred in oil supply security. (b) The Rate Of Equity(ROE), a crucial factor in town-gas pricing which is strictly controlled, is directly connected to the average interest rate on saving accounts of domestic commercial banks. Some arguments may have rise about inclusion a risk factor on ROE in order to compensate the uncertainty of town-gas business. (c) New demand for natural gas which is generated by new technologies or machinery and tools can help reduce the costs occurred from seasonal imbalance between power sector and gas sector. So it is also important to decide how to include the beneficiary of cost reduction in town-gas pricing. In order to evaluate the proper price levels, this study tests energy supply security by adopting methodologies such as Herfindahl Index and Portfolio Variance Risk. They can help develop the method to effectively improve the energy security and include the proper energy security costs into energy prices. This study also provides some suggestions for betterment of current ROE decision rule in town-gas business and for improvement of current town-gas policy that government subsidizes newly developed demand for strengthening price competitiveness in the early stage. (author). 145 refs., 16 figs., 49 tabs.

  13. A Comparative Study of Current and Potential Users of Mobile Payment Services

    Directory of Open Access Journals (Sweden)

    Chanchai Phonthanukitithaworn

    2016-11-01

    Full Text Available Previous studies of mobile payment (m-payment services have primarily focused on a single group of adopters. This study identifies the factors that influence an individual’s intention to use m-payment services and compares groups of current users (adopters with potential users (non-adopters. A research model that reflects the behavioral intention to use m-payment services is developed and empirically tested using structural equation modeling on a data set consisting of 529 potential users and 256 current users of m-payment services in Thailand. The results show that the factors that influence current users’ intentions to use m-payment services are compatibility, subjective norms, perceived trust, and perceived cost. Subjective norms, compatibility, ease of use, and perceived risk influenced potential users’ intentions to use m-payment. Subjective norms and perceived risk had a stronger influence on potential users, while perceived cost had a stronger influence on current users, in terms of their intentions to use m-payment services. Discussions, limitations, and recommendations for future research are addressed.

  14. Studying the start of the Maunder Minimum to understand the current situation

    Science.gov (United States)

    Neuhäuser, Ralph; Neuhäuser, Dagmar L.

    2016-04-01

    To investigate whether we now enter a Maunder-like grand minimum, we have to compare the current situation with the time around the start of the Maunder minimum. Sunspot observations in the 1610s are of particular importance and relevance, because they are shortly before the start of the Maunder Grand Minimum. While the Maunder Minimum it is usually dated from 1645 to 1715, Vaquero & Trigo (2015) argue that what they call the "Extended Maunder Minimum" would have started in 1618 during or around a Schwabe cycle minimum around that time. We have therefore studied the sunspot record of that time in detail. Hoyt & Schatten (1998) compiled for all known telescopic observers a list of their observations; recent solar activity studies for the past four centuries are based on their compilation. In addition to 12 observers listed by Hoyt & Schatten (1998) for the 1610s, we list six more observers with datable spot observations. Furthermore, while Hoyt & Schatten (1998) argue that Simon Marius would have observed from mid 1617 to the end of 1618 almost every day, but would have never seen a spot, we can show with the original reports by Marius that he observed from Aug 1611 to spring 1619 with a lot of sunspot detections. Similar, while Hoyt & Schatten (1998) argue that Giovanni Riccioli would have observed on almost every day in 1618, but would have never seen a spot, he did not report any own observations at all that year, but quoted Argoli for that there were no spots during the periods with comets in 1618. The data base by Hoyt & Schatten (1998) has several more errors in the 1610s, as we show also for the observations by Harriot, Scheiner, Malapert, Saxonius, and Tarde. We also compare drawings from Jungius with the observations by Harriot, Galilei, and Marius. In contrast to what is specified in Hoyt & Schatten (1998), after Harriot, the two Fabricius (father and son), Scheiner and Cysat, Marius and Schmidnerus are among the earliest datable telescopic sunspot

  15. About the Investigation of Art Students’ English Study

    Institute of Scientific and Technical Information of China (English)

    吴婧; 祁素萍

    2012-01-01

      English study is becoming more and more important. However, art students have weak English level on average. Thus, it’ s a problem for students and teachers to improve the quality of English study. In this article, it analyses the reason for the weak English level and the responding strategy. What’ s more, it encourages students to study actively and advocates teach⁃ing based on art knowledge.

  16. On the study of phase formation and critical current density in superconducting MgB2

    Indian Academy of Sciences (India)

    Suchitra Rajput; Sujeet Chaudhary; Subhash C Kashyap; Pankaj Srivastava

    2006-06-01

    Superconducting bulk MgB2 samples have been synthesized by employing sintering technique without using any additional process steps, generally undertaken in view of the substantial loss of magnesium, during heat treatment. Starting with Mg rich powders having different atomic ratios of Mg : B, as against the nominally required Mg : B = 1 : 2 ratio, we have obtained superconducting MgB2 samples of different characteristics. The effect of excess Mg in the starting mixture and processing temperature on the phase-formation, transition temperature (C) and critical current density (C) have been investigated by electrical transport and a.c. susceptibility measurements. The X-ray diffraction and X-ray photoelectron spectroscopic analyses of MgB2 bulk samples have been carried out to understand the role of excess Mg and the effect of processing temperature. It is established that MgB2 samples with high critical current density can be synthesized from a Mg rich powder having Mg : B in 2 : 2 ratio, at temperatures around 790°C. Critical current density has been found to vary systematically with processing temperature.

  17. A study on centrifugal charaging pump shaft failure investigation

    Energy Technology Data Exchange (ETDEWEB)

    Jo, S. D.; Kim, B. K. [KEPCO, Woolsan (Korea, Republic of)

    2001-05-01

    Pump shafts in the centrifugal charging safety injection pumps in PWRs have been subject to occasional failures over the past several years. Service experience showed that the pump shaft failures can result in significant emergency repair and maintenance costs to the plant. Metallurgical investigations of the pump shafts fabricated prior to 1977 confirmed that the cracking was initiated at stress concentrations sitcs, such as a locknut thread root or a split ring groove, and progressed by a high cycle fatigue mechanism. Westinghouse implemented a series of improvements and upgrades to increase the safety margins and to mitigate the effect of the off-design operating conditions. These included design enhancements as well as material condition (heat treatment) modifications. The pump shaft upgrading program significantly improved the design life of the shafts but did not fully mitigate the issue. Investigation of recent failures of the upgraded shafts suggested that these failures are initiated by a combination of off-design loading events such as loss of flow or gas binding and a reduction of pump shaft resistance to cracking due to the aqueous environmental conditions.

  18. Using Listener Judgments to Investigate Linguistic Influences on L2 Comprehensibility and Accentedness: A Validation and Generalization Study

    Science.gov (United States)

    Saito, Kazuya; Trofimovich, Pavel; Isaacs, Talia

    2017-01-01

    The current study investigated linguistic influences on comprehensibility (ease of understanding) and accentedness (linguistic nativelikeness) in second language (L2) learners' extemporaneous speech. Target materials included picture narratives from 40 native French speakers of English from different proficiency levels. The narratives were…

  19. Main nutrient patterns and colorectal cancer risk in the European Prospective Investigation into Cancer and Nutrition study

    NARCIS (Netherlands)

    Moskal, Aurélie; Freisling, Heinz; Byrnes, Graham; Assi, Nada; Fahey, Michael T.; Jenab, Mazda; Ferrari, Pietro; Tjønneland, Anne; Petersen, Kristina EN; Dahm, Christina C.; Hansen, Camilla Plambeck; Affret, Aurélie; Boutron-Ruault, Marie Christine; Cadeau, Claire; Kühn, Tilman; Katzke, Verena; Iqbal, Khalid; Boeing, Heiner; Trichopoulou, Antonia; Bamia, Christina; Naska, Androniki; Masala, Giovanna; de Magistris, Maria Santucci; Sieri, Sabina; Tumino, Rosario; Sacerdote, Carlotta; Peeters, Petra H.; Bueno-de-Mesquita, Bas H.; Engeset, Dagrun; Licaj, Idlir; Skeie, Guri; Ardanaz, Eva; Buckland, Genevieve; Castaño, José M Huerta; Quirós, José R.; Amiano, Pilar; Molina-Portillo, Elena; Winkvist, Anna; Myte, Robin; Ericson, Ulrika; Sonestedt, Emily; Perez-Cornago, Aurora; Wareham, Nick; Khaw, Kay Tee; Huybrechts, Inge; Tsilidis, Konstantinos K.; Ward, Heather; Gunter, Marc J.; Slimani, Nadia

    Background:Much of the current literature on diet–colorectal cancer (CRC) associations focused on studies of single foods/nutrients, whereas less is known about nutrient patterns. We investigated the association between major nutrient patterns and CRC risk in participants of the European Prospective

  20. Investigating the Place and Meaning of "Physical Education" to Preschool Children: Methodological Lessons from a Research Study

    Science.gov (United States)

    McEvilly, Nollaig

    2015-01-01

    Preschool physical education has not been extensively researched. Furthermore, research in physical activity and physical education rarely seeks young children's perspectives. The current paper focuses on one aspect of a post-structural study concerned with investigating the place and meaning of "physical education" to practitioners and…

  1. An Investigation on Teaching Materials Used in Social Studies Lesson

    Science.gov (United States)

    Saglam, Halil Ibrahim

    2011-01-01

    The purpose of this study is to analyze the teaching materials employed during social studies lessons on the basis of certain variables. Specifically, the researcher tried to find out whether teachers' gender, service length, having a personal computer, receiving an in-service training regarding the use of teaching materials, having an interest on…

  2. The Scientific Investigation of Creativity: What Should We Study?

    Science.gov (United States)

    Calkins, Roderick P.; Welkowitz, Lawrence

    1984-01-01

    Two studies related to creativity are reported and discussed. The first examined possible relationships between problem solving, divergent thinking, and field dependence-independence in second-grade students (N=83). The second study determined that the analytical skills of 71 undergraduate students (measured by the Hidden Figures Test) may be…

  3. A study of EWOD-driven droplets by PIV investigation.

    Science.gov (United States)

    Lu, Hsiang-Wei; Bottausci, Frederic; Fowler, Jesse D; Bertozzi, Andrea L; Meinhart, Carl; Kim, Chang-Jin C J

    2008-03-01

    Despite the recent interest in droplet-based microfluidics using electrowetting-on-dielectric (EWOD), fundamental understanding of the fluid dynamics remains limited to two-dimensional (2D) reduction of the Navier-Stokes equation. Experimental data are in dire need to verify the predictions and advance the field. We report an investigation of the flow inside droplets actuated by EWOD in air using micro particle image velocimetry (micro-PIV). Using the continuity equation, we reconstruct the 3D velocity field from the 2D PIV experimental data. We present some fundamental findings and build valuable insights that will help design sophisticated EWOD microfluidic devices. For example, the results confirm that efficient mixing in a droplet may be achieved by moving the droplet along an irreversible pattern that breaks the symmetry of the two circulating inner flows.

  4. Investigating uncertainty in BPR formula parameters: a case study

    DEFF Research Database (Denmark)

    Manzo, Stefano; Nielsen, Otto Anker; Prato, Carlo Giacomo

    uncertainty within the model. The research described in this paper investigated uncertainty in the BPR formula parameters. Within traffic assignment models, the relationship between travel time and traffic flows is commonly described by the BPR formula. The BPR formula works as a link performance function......; given free flow travel time, observed flow and link capacity, it uses parameters to fit the equation to various types of roadways and circumstances. Usually, the values for the parameters are pre-defined, based on assumptions and practice. The present paper describes a work implemented to define the BPR...... on their output highly unreliable. The main consequence of this inherent uncertainty is that modelled traffic flows cannot be expressed as a point estimate, because this would only represent one of the possible outputs generated by the model. Instead, modelled traffic flows are better expressed as a central...

  5. Review of the Studies about Environmental Education: Current Status in Turkey

    Directory of Open Access Journals (Sweden)

    Esra Kızılay

    2014-12-01

    Full Text Available Purpose of this research is to reveal current status of studies in environmental education, which were published in Turkey between 2007-2011. Within the content of this study, 112 studies were reviewed using content analysis based on the following grouping criteria; i.e., publication year, language, participant, research design, research topic, data gathering instruments and data analysis program. The results indicated that 78% of them were published in Turkish and most of them were at university level (36.2%.A majority of the reviewed studies were about affective domain (31.9%. Quantitative studies (57.1% were very commonly used by the researchers . Questionnaires (45% were the most commonly used data gathering instruments, and SPSS was the most frequently used quantitative data analysis program (88.6%. Presenting an overview of relevant literature, this study may guide the researchers who will conduct further studies on environmental education.

  6. Experimental study on hydrodynamic characteristics of vertical-axis floating tidal current energy power generation device

    Science.gov (United States)

    Ma, Yong; Li, Teng-fei; Zhang, Liang; Sheng, Qi-hu; Zhang, Xue-wei; Jiang, Jin

    2016-10-01

    To study the characteristics of attenuation, hydrostatic towage and wave response of the vertical-axis floating tidal current energy power generation device (VAFTCEPGD), a prototype is designed and experiment is carried out in the towing tank. Free decay is conducted to obtain attenuation characteristics of the VAFTCEPGD, and characteristics of mooring forces and motion response, floating condition, especially the lateral displacement of the VAFTCEPGD are obtained from the towing in still water. Tension response of the #1 mooring line and vibration characteristics of the VAFTCEPGD in regular waves as well as in level 4 irregular wave sea state with the current velocity of 0.6 m/s. The results can be reference for theoretical study and engineering applications related to VAFTCEPGD.

  7. Investigating Mobile Money Acceptance in Somalia: An Empirical Study

    Directory of Open Access Journals (Sweden)

    Osman Sayid

    2012-12-01

    Full Text Available The main purpose of this paper is to study the perception and willingness of Somali customers to adopt mobile money, based on an upgraded version of technology acceptance model. The questionnaire used in this study was distributed to 100 Somali customers, and the data gathered were then analysed using multiple regression and onesample t-test. The results indicate that perceived ease of use has a significant positive influence on the perceived usefulness of mobile money. Moreover, perceived usefulness and security were found to have a significant positive influence on attitude. Finally, social influence together with perceived usefulness both have significant positive influence on the Somali customers’ intention to adopt mobile money. This is one of the first studies to be conducted on mobile money in Somalia, the study uses an upgraded version of technology acceptance model and it reports significant findings based on thisapproach.

  8. A MATLAB-Based Boundary Data Simulator for Studying the Resistivity Reconstruction Using Neighbouring Current Pattern

    OpenAIRE

    Tushar Kanti Bera; Nagaraju, J.

    2013-01-01

    Phantoms are essentially required to generate boundary data for studying the inverse solver performance in electrical impedance tomography (EIT). A MATLAB-based boundary data simulator (BDS) is developed to generate accurate boundary data using neighbouring current pattern for assessing the EIT inverse solvers. Domain diameter, inhomogeneity number, inhomogeneity geometry (shape, size, and position), background conductivity, and inhomogeneity conductivity are all set as BDS input variables. D...

  9. Current methods for studying dynamic processes in the ionosphere. Sovremennye metody issledovaniia dinamicheskikh protsessov v ionosfere

    Energy Technology Data Exchange (ETDEWEB)

    Filipp, N.D.; Blaunshtein, N.SH.; Erukhimov, L.M.; Ivanov, V.A.; Uriadov, V.P.

    1991-01-01

    Current experimental and theoretical data relevant to the study of dynamic processes in the ionospheric plasma using state-of-the-art methods are summarized. The methods used include linear FM sounding, partial radio wave reflection, oblique-incidence radio wave scattering, radio wave heating of the ionosphere, plasma injection, and computer simulation of physical processes. For each specific method, experimental data are compared against theoretical predictions and numerical calculations. 251 refs.

  10. An Investigation of Factors Determining the Study Abroad Destination Choice: A Case Study of Taiwan

    Science.gov (United States)

    Lee, Cheng-Fei

    2014-01-01

    Previous studies on the field of education abroad have mainly focused on the factors influencing the mobility of international students from developing to developed countries and very few have been conducted to investigate the factors influencing the flow of international students to the Asia Pacific region. As a piece of country-specific…

  11. Study of Government Support System in SMEs: An Empirical Investigation

    Directory of Open Access Journals (Sweden)

    Hussain Bux Marri

    2011-07-01

    Full Text Available The SMEs (Small and Medium Enterprises have created its own place and value universally, no matter how tough global competition is there in international market. This research work was undertaken to assess the increase in importance of SMEs in growing nations such as Pakistan and to highlight the importance of SMEs. This paper is validated through research work undertaken by domestic and worldwide scholars. Research work was carried out in enterprises of Sindh, province of Pakistan, using questionnaire and personal discussions with business owners/entrepreneurs of enterprises. Their response was very positive on parameters which were focused towards taxation policies (Rebate, government technological support, financial support and loan facilities. In addition to this, the results were further investigated and measured through statistical measures such as mean/average, which indicate that majority of enterprises, were not happy with country\\'s administration in terms of support they receive. Whereas, there are noticeable indications that government\\'s assistance to small and medium enterprises is very necessary at every stage. Enterprises which have received assistance from their governments have proved to be successful in developing nations.

  12. Investigating Cooperative Behavior in Ecological Settings: An EEG Hyperscanning Study

    Science.gov (United States)

    Petti, Manuela; He, Eric J.; De Giusti, Vittorio; He, Bin; Astolfi, Laura; Babiloni, Fabio

    2016-01-01

    The coordinated interactions between individuals are fundamental for the success of the activities in some professional categories. We reported on brain-to-brain cooperative interactions between civil pilots during a simulated flight. We demonstrated for the first time how the combination of neuroelectrical hyperscanning and intersubject connectivity could provide indicators sensitive to the humans’ degree of synchronization under a highly demanding task performed in an ecological environment. Our results showed how intersubject connectivity was able to i) characterize the degree of cooperation between pilots in different phases of the flight, and ii) to highlight the role of specific brain macro areas in cooperative behavior. During the most cooperative flight phases pilots showed, in fact, dense patterns of interbrain connectivity, mainly linking frontal and parietal brain areas. On the contrary, the amount of interbrain connections went close to zero in the non-cooperative phase. The reliability of the interbrain connectivity patterns was verified by means of a baseline condition represented by formal couples, i.e. pilots paired offline for the connectivity analysis but not simultaneously recorded during the flight. Interbrain density was, in fact, significantly higher in real couples with respect to formal couples in the cooperative flight phases. All the achieved results demonstrated how the description of brain networks at the basis of cooperation could effectively benefit from a hyperscanning approach. Interbrain connectivity was, in fact, more informative in the investigation of cooperative behavior with respect to established EEG signal processing methodologies applied at a single subject level. PMID:27124558

  13. CCD Photometric Study and Period Investigation of AH Tauri

    Science.gov (United States)

    Xiang, Fu-Yuan; Xiao, Ting-Yu; Yu, Yun-Xia

    2015-07-01

    In this paper, we present new CCD photometric observations of AH Tauri in the R band observed in 2006 at the Yunnan Observatory. Two new times of light minima were derived from these observations. We modeled the light curves using the 2003 version of the Wilson-Devinney program. The results show that the variations of the light curves can be expained by a cool spot on the primary star. The fill-out factor is about 6.6%, indicating that AH Tauri is a shallow-contact system. The mass ratio was determined to be about 0.505. In addition, the orbital period variations of AH Tauri were investigated based on all of the photoelectric and CCD light minimum times, including our two new data. It was found that the orbital period exhibits a possible periodic variation with a period of {P}{mod}=54.62\\(+/- 0.20) years and a secular period decrease of {dP}/{dt}=-(1.823+/- 0.215)× {10}-7 {days} {{yr}}-1. Since AH Tauri is an overcontact solar-like system, we discuss three mechanisms of the mass transfer, the light-time effect of the third body, and magnetic activity responsible for the orbital period changes.

  14. Investigating Cooperative Behavior in Ecological Settings: An EEG Hyperscanning Study.

    Science.gov (United States)

    Toppi, Jlenia; Borghini, Gianluca; Petti, Manuela; He, Eric J; De Giusti, Vittorio; He, Bin; Astolfi, Laura; Babiloni, Fabio

    2016-01-01

    The coordinated interactions between individuals are fundamental for the success of the activities in some professional categories. We reported on brain-to-brain cooperative interactions between civil pilots during a simulated flight. We demonstrated for the first time how the combination of neuroelectrical hyperscanning and intersubject connectivity could provide indicators sensitive to the humans' degree of synchronization under a highly demanding task performed in an ecological environment. Our results showed how intersubject connectivity was able to i) characterize the degree of cooperation between pilots in different phases of the flight, and ii) to highlight the role of specific brain macro areas in cooperative behavior. During the most cooperative flight phases pilots showed, in fact, dense patterns of interbrain connectivity, mainly linking frontal and parietal brain areas. On the contrary, the amount of interbrain connections went close to zero in the non-cooperative phase. The reliability of the interbrain connectivity patterns was verified by means of a baseline condition represented by formal couples, i.e. pilots paired offline for the connectivity analysis but not simultaneously recorded during the flight. Interbrain density was, in fact, significantly higher in real couples with respect to formal couples in the cooperative flight phases. All the achieved results demonstrated how the description of brain networks at the basis of cooperation could effectively benefit from a hyperscanning approach. Interbrain connectivity was, in fact, more informative in the investigation of cooperative behavior with respect to established EEG signal processing methodologies applied at a single subject level.

  15. Investigating Cooperative Behavior in Ecological Settings: An EEG Hyperscanning Study.

    Directory of Open Access Journals (Sweden)

    Jlenia Toppi

    Full Text Available The coordinated interactions between individuals are fundamental for the success of the activities in some professional categories. We reported on brain-to-brain cooperative interactions between civil pilots during a simulated flight. We demonstrated for the first time how the combination of neuroelectrical hyperscanning and intersubject connectivity could provide indicators sensitive to the humans' degree of synchronization under a highly demanding task performed in an ecological environment. Our results showed how intersubject connectivity was able to i characterize the degree of cooperation between pilots in different phases of the flight, and ii to highlight the role of specific brain macro areas in cooperative behavior. During the most cooperative flight phases pilots showed, in fact, dense patterns of interbrain connectivity, mainly linking frontal and parietal brain areas. On the contrary, the amount of interbrain connections went close to zero in the non-cooperative phase. The reliability of the interbrain connectivity patterns was verified by means of a baseline condition represented by formal couples, i.e. pilots paired offline for the connectivity analysis but not simultaneously recorded during the flight. Interbrain density was, in fact, significantly higher in real couples with respect to formal couples in the cooperative flight phases. All the achieved results demonstrated how the description of brain networks at the basis of cooperation could effectively benefit from a hyperscanning approach. Interbrain connectivity was, in fact, more informative in the investigation of cooperative behavior with respect to established EEG signal processing methodologies applied at a single subject level.

  16. Investigation of electric charge transport in conjugated polymer P3HT: PCBM solar cell with temperature dependent current and capacitance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Peiqing; Mencaraglia, Denis; Darga, Arouna; Migan, Anne [Laboratoire de Genie Electrique de Paris, CNRS UMR 8507, SUPELEC, UPMC, Universite Paris VI, Universite Paris-Sud, 11 Rue Joliot Curie, Plateau de Moulon, 91192 Gif-Sur-Yvette Cedex (France); Rabdbeh, Roshanak; Ratier, Bernard; Moliton, Andre [Institut Carnot XLim, UMR 6172, CNRS, Universite de Limoges, 123 Avenue Albert Thomas, 87060 Limoges Cedex (France)

    2010-04-15

    We investigated quantitatively the electronic transport properties of a bulk heterojunction polymer/fullerene solar cell, based on structure Glass/ITO/P3HT:PCBM/Al. The current-voltage I-V characteristics in the intermediate positive bias and temperature regime (0.2 V {<=} V {<=} 1.5 V, 180 K {<=} T {<=} 250 K) can be well fitted by a modified Poole-Frenkel PF detrapping model. Combining these results with the high frequency capacitance measurements, we could then derive independently the absorber thickness and its dielectric constant. At low temperature (80 K {<=} T {<=} 170 K), the I-V data can be well accounted for with Space Charge Limited Current (SCLC) regimes. At intermediate positive bias (1 V {<=} V {<=} 2.3 V), the current is dominated by the trapped space charges with an exponential traps distribution, while at high positive bias (2.5 V {<=} V {<=} 4 V), the space charges due to injected free carrier play an important role for the conduction. From the fits to the two different SCLC models, we could then extract the electrically active defects parameters controlling the transport. These parameters were confirmed by space charge capacitance spectroscopy (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  17. Study on Eddy-current of Disc Permanent-magnet Eddy-current Couplings%盘式永磁涡流耦合器涡流研究

    Institute of Scientific and Technical Information of China (English)

    上官璇峰; 杨帅

    2015-01-01

    本文旨在研究盘式涡流耦合器涡流分布特点。采用解析法得到了涡流密度的函数表达式;利用三维有限元法分别计算正常工作状态和起动状态下涡流径向分量和周向分量沿径向和周向分布的三维图形并总结涡流沿周向、径向、轴向的分布特点。根据涡流密度的函数表达式着重分析了导体盘材料、气隙长度和转差率三个重要因素对涡流的影响。通过对盘式永磁涡流耦合器涡流特点的把握,合理的解释了轴向磁力随转差率变化的规律。%The purpose of this paper is to study the changing discipline of eddy-current of disc permanent-magnet eddy-current coupling.Analytical method was adopted to get expression of the eddy-current density. 3D FEMwas adopted to obtain the 3D distribution graph along with radial and circumferential direction of eddy-current on radial and circumferential components.And the characteristics of distribution of eddy-current along with radial,circumferential and axial directions were summarized.Three important factors of the influence of eddy-current,conductor plate material,air-gap length and slip were analyzed according to the expression of eddy-current density.Through the grasp of the characteristics of eddy-current,the law of the axial magnetic force changing with slip was explained reasonably.

  18. Ancient Dwarka: Study based on recent underwater archaeological investigations

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.; Sundaresh; Tripati, S.

    suggest that Dwarka was one of the most busy port centers during the past on the west coast of India. The comparative study of surrounding sites indicates that the date of the structures of Dwarka may be between Historical period and late medieval period...

  19. Science Teacher Left behind: A Case Study Investigation

    Science.gov (United States)

    Jackson, Dionne B.; Talbert, Tony L.

    2012-01-01

    We used the single-case study method to develop an in-depth profile of Yajaira's (pseudonym) instruction based on her epistemological beliefs and science education experiences. We selected the participant using criterion based, purposeful sampling. Data collection included semi-structured interviews, direct observations, and the collection of…

  20. Interrelations that foster learning: An investigation of two correlational studies.

    Science.gov (United States)

    Phan, Huy P

    2016-06-01

    The theoretical tenets of academic engagement, as outlined by Schaufeli and colleagues, have received limited attention. There is credence to indicate that Schaufeli et al.'s conceptualization has educational implications. Extending this avenue of inquiry, we report two longitudinal studies that explore the motivation-related attributes of engagement within the framework of self-efficacy. A number of research questions were developed for examination-for example, does enactive learning experience influence academic achievement, via students' engrossment (i.e. absorption) of a subject matter? Does students' sense of resilience and persistence (i.e. vigor) heighten their self-efficacy beliefs for academic learning? For the two studies (Study 1: 311 Year 11 students; Study 2: 249 Year 12 students), utilizing different cohorts, we measured these constructs at multiple time points. Existing Likert-scale inventories were administered repeatedly, and data collected were analysed using causal modeling procedures. MPlus 7.2 yielded a number of key findings-for example: (a) the positive impact of Time 1 enactive learning experience on Time 2 absorption and vigor, (b) the positive impact of Time absorption on Time 3 self-efficacy, (c) the positive impact of Time 2 absorption on Time 4 achievement and (d) the positive impact of Time 1 self-efficacy on Time 2 absorption and vigor.

  1. Investigation into feed preparation for regulatory fish metabolism studies.

    Science.gov (United States)

    Goeritz, Ina; Atorf, Cornelia; Whalley, Paul; Seymour, Paul; Klein, Michael; Schlechtriem, Christian

    2014-02-01

    Test diets used in fish metabolism studies for regulatory purposes must be homogenously fortified with the radiolabelled test substance and stable with respect to leaching. Standard fish food, as used in commercial fish farming, should also be used in fish metabolism studies. Therefore, suitable spiking and coating procedures are required to ensure the correct dosing of the fish during the experiment. Methods for the homogeneous, safe and efficient application of radiolabelled test items to the surface of commercial feeding pellets were developed. Leaching studies showed that test items of low lipophilicity applied to feeding pellets need to be stabilised, to reduce the risk of significant losses prior to ingestion by the fish. Coating of solvent-spiked pellets with calcium alginate was shown to reduce leaching losses of water-soluble test items significantly. Alternatively, commercial feeding pellets can be coated with alginate or vegetable oil fortified with a radiolabelled test item also leading to sufficiently stabilised test diets. Experimental conditions, such as the water temperature, may have a significant effect on the leaching behaviour of the test items. A detailed description of different spiking and coating procedures for the preparation of experimental diets suitable for fish metabolism studies is provided. © 2013 Society of Chemical Industry.

  2. Investigator Bias in Urodynamic Studies for Functional Urinary Incontinence

    NARCIS (Netherlands)

    Bael, An; Verhulst, John; Lax, Hildegard; Hirche, Herbert; van Gool, Jan D.

    2009-01-01

    Purpose: In the setting of the European Bladder Dysfunction Study, a multi-center, randomized, controlled trial of treatment options for functional incontinence in children, we assessed the concordance between reported and reviewed urodynamic scores. Materials and Methods: A total of 97 children wit

  3. Experimentally-Based Computational Investigation into Beat-To-Beat Variability in Ventricular Repolarization and Its Response to Ionic Current Inhibition.

    Directory of Open Access Journals (Sweden)

    E Pueyo

    Full Text Available Beat-to-beat variability in repolarization (BVR has been proposed as an arrhythmic risk marker for disease and pharmacological action. The mechanisms are unclear but BVR is thought to be a cell level manifestation of ion channel stochasticity, modulated by cell-to-cell differences in ionic conductances. In this study, we describe the construction of an experimentally-calibrated set of stochastic cardiac cell models that captures both BVR and cell-to-cell differences in BVR displayed in isolated canine action potential measurements using pharmacological agents. Simulated and experimental ranges of BVR are compared in control and under pharmacological inhibition, and the key ionic currents determining BVR under physiological and pharmacological conditions are identified. Results show that the 4-aminopyridine-sensitive transient outward potassium current, Ito1, is a fundamental driver of BVR in control and upon complete inhibition of the slow delayed rectifier potassium current, IKs. In contrast, IKs and the L-type calcium current, ICaL, become the major contributors to BVR upon inhibition of the fast delayed rectifier potassium current, IKr. This highlights both IKs and Ito1 as key contributors to repolarization reserve. Partial correlation analysis identifies the distribution of Ito1 channel numbers as an important independent determinant of the magnitude of BVR and drug-induced change in BVR in control and under pharmacological inhibition of ionic currents. Distributions in the number of IKs and ICaL channels only become independent determinants of the magnitude of BVR upon complete inhibition of IKr. These findings provide quantitative insights into the ionic causes of BVR as a marker for repolarization reserve, both under control condition and pharmacological inhibition.

  4. A Snapshot Study of Current Practices among Sellers of Translation Services between Japanese and English

    Directory of Open Access Journals (Sweden)

    Dr. Stephen Crabbe

    2015-11-01

    Full Text Available A two-part study was launched in light of the Japan Translation Federation’s 2012 statement in its guide, 翻訳で失敗しないために翻訳発注の手引き [lit. For not getting it wrong with translation: a guide to ordering translation], that “外国語の文書を母国語に翻訳するのがプロの原則です” [lit. It is a fundamental principle that professional translators work into their native languages] (Japan Translation Federation, 2012, p. 15. The key goal is to gauge the extent to which this 2012 statement is reflected in current practices among the sellers and buyers of translation services between Japanese and English. In this paper, which describes the first part of the study, the focus is on the practices of sellers of translation services between Japanese and English: specifically, professional freelance translators. Twenty-four professional freelance translators completed an online questionnaire. The results of this questionnaire, first, suggest that current practices among sellers of translation services between Japanese and English are consistent with the Japan Translation Federation’s 2012 statement and, second, broadly support secondary literature on L1 translation (translation into the first language and L2 translation (translation into the second language. Whilst this is only a snapshot of current practices among sellers of translation services between Japanese and English, the overall results are informative. In the second, follow-up part of the study the focus will be on the current practices of buyers of translation services between Japanese and English.

  5. A preliminary study of material homogeneity for size effect investigations

    Energy Technology Data Exchange (ETDEWEB)

    Krompholz, K.; Kamber, J.; Kalkhof, D.

    1999-06-01

    The forged material 20 MnMoNi 55, material number 1.6310 (heat number 69906) with a heat treatment of 900 {sup o}C, water quenched, 730 {sup o}C, air cooled, was subjected to an intensive quality control consisting of chemical analysis, metallography, hardness tests, tensile tests, and impact tests. Six plates of the material were investigated, and all specimens were taken from a diagonal of each plate in three positions, outer margins and the centre of the plates. The quality control exhibits the following results: (1) The material fulfill the material specification in all respects. (2) This material is a fine grained homogeneous ferritic material of bainitic structure; neither from the chemical analysis, metallography, nor from hardness tests influences from the position of the specimens taken from the plates could be derived. (3) The tensile tests clearly revealed position dependent material properties. With the exception of one plate, one of the selected positions exhibits no natural yield strength, higher rupture strength, and lower elongation to fracture compared with the other two positions at 293 K and 573 K. (4) Many of the data obtained from the impact tests at room temperature were larger than the capacity of the impact machine, i.e. 225 Joule; the experimental condition was changed from tests at 573 K to tests at 253 K to obtain data from the transition region. The main conclusions drawn for the size effect experiments where that all the tensile test results for different specimen sizes have to be discussed with respect of the specimen positions within the plates, and that for all bend bar as well as impact experiments with different specimen sizes the notch depth to specimen width ratio a/w has to be changed from a/w = 0.2 to a/w = 0.3 to get reasonable results within the frame of the available test equipment. (author)

  6. NO adsorption studies on silicene nanosheet: DFT investigation

    Energy Technology Data Exchange (ETDEWEB)

    Chandiramouli, R., E-mail: rcmoulii@gmail.com [School of Electrical & Electronics Engineering, SASTRA University, Tirumalaisamudram, Thanjavur 613 401 (India); Srivastava, Anurag [Advanced Materials Research Group, Computational Nanoscience & Technology Laboratory, ABV-Indian Institute of Information Technology & Management Gwalior (M.P.), Gwalior 474 015 (India); Nagarajan, V. [School of Electrical & Electronics Engineering, SASTRA University, Tirumalaisamudram, Thanjavur 613 401 (India)

    2015-10-01

    Graphical abstract: - Highlights: • The adsorption characteristics of NO on silicene nanosheets are studied using density functional theory. • The NO adsorption characteristics are studied in pristine, Al and P substituted silicene nanosheet. • NO adsorption properties depend on adsorbed energy, HOMO-LUMO gap and Mulliken charge transfer. • The substitution of P atoms in silicene nanosheet enhances the NO adsorption properties. - Abstract: The electronic properties, structural stability and nitric oxide (NO) adsorption characteristics on pristine, Al and P substituted silicene nanosheet are studied using density functional theory with B3LYP/LanL2DZ basis set. The structural stability of silicene nanostructure is discussed in terms of formation energy. The formation energy, dipole moment, point symmetry, ionization potential and electron affinity of silicene nanosheet are reported. The adsorption characteristics of NO on silicene nanosheet are explored in terms of adsorption energy, energy gap and Mulliken charge transfer. The favorable adsorption site of NO on silicene nanosheet is identified and reported. From the observations, it is inferred that the adsorption characteristics of NO are prominent on pristine and P substituted silicene nanosheet.

  7. CRITICAL CURRENT AND JUNCTION BETWEEN PANCAKE STUDIES FOR HTS COIL DESIGN

    CERN Document Server

    Lécrevisse, Y; Louchart, O; Rey, J-M; Tixador, P

    2011-01-01

    YBCO Coated Conductor (CC) are very attractive for very high magnetic field coil with lower cryogenics need. We study two major aspects of HTS coil building. First the results of critical current measurements on YBCO tape provided by SuperPower are presented for a large temperature range and in parallel magnetic field configuration. A model is also proposed to extrapolate those measurements at other temperatures and fields. Then we focus on the critical aspect of junctions between pancakes. Junctions in cylindrical configuration are studied using three different soldering materials. The results are promising for further coil building.

  8. Affective bias and current, past and future adolescent depression: A familial high risk study

    Science.gov (United States)

    Kilford, Emma J.; Foulkes, Lucy; Potter, Robert; Collishaw, Stephan; Thapar, Anita; Rice, Frances

    2015-01-01

    Background Affective bias is a common feature of depressive disorder. However, a lack of longitudinal studies means that the temporal relationship between affective bias and depression is not well understood. One group where studies of affective bias may be particularly warranted is the adolescent offspring of depressed parents, given observations of high rates of depression and a severe and impairing course of disorder in this group. Methods A two wave panel design was used in which adolescent offspring of parents with recurrent depression completed a behavioural task assessing affective bias (The Affective Go/No Go Task) and a psychiatric interview. The affective processing of adolescents with current, prior and future depressive disorder was compared to that of adolescents free from disorder. Results Adolescents with current depression and those who developed depression at follow-up made more commission errors for sad than happy targets compared to adolescents free from disorder. There was no effect of prior depression on later affective processing. Limitations Small cell sizes meant we were unable to separately compare those with new onset and recurrent depressive disorder. Conclusions Valence-specific errors in behavioural inhibition index future vulnerability to depression in adolescents already at increased risk and may represent a measure of affective control. Currently depressed adolescents show a similar pattern of affective bias or deficits in affective control. PMID:25527997

  9. Current practice in continuous renal replacement therapy: An epidemiological multicenter study.

    Science.gov (United States)

    Tomasa Irriguible, T M; Sabater Riera, J; Poch López de Briñas, E; Fort Ros, J; Lloret Cora, M J; Roca Antònio, J; Navas Pérez, A; Ortiz Ballujera, P; Servià Goixart, L; González de Molina Ortiz, F J; Rovira Anglès, C; Rodríguez López, M; Roglan Piqueras, A

    2017-05-01

    The aim of the study is to ascertain the most relevant aspects of the current management of renal replacement therapy (RRT) in critically ill patients, and to analyze renal function recovery and mortality in patients undergoing RRT. A non-interventional three-month observational study was made in 2012, with a follow-up period of 90 days, in 21 centers in Catalonia (Spain). Demographic information, severity scores and clinical data were obtained, as well as RRT parameters. patients aged ≥ 16 years admitted to Intensive Care Units (ICUs) and subjected to RRT. A total of 261 critically ill patients were recruited, of which 35% had renal dysfunction prior to admission. The main reason for starting RRT was oliguria; the most widely used RRT modality was hemodiafiltration; and the median prescribed dose at baseline was 35mL/kg/h. The median time of RRT onset from ICU admission was one day. The mortality rate at 30 and 90 days was 46% and 54%, respectively, and was associated to greater severity scores and a later onset of RRT. At discharge, 85% of the survivors had recovered renal function. Current practice in RRT in Catalonia abides with the current clinical practice guidelines. Mortality related to RRT is associated to later onset of such therapy. The renal function recovery rate at hospital discharge was 85% among the patients subjected to RRT. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  10. The current status of structural studies on proteins of the myelin sheath (Review).

    Science.gov (United States)

    Kursula, P

    2001-11-01

    Myelin, the multilayered membrane structure surrounding axons, provides a unique environment to its proteins, which are either transmembrane proteins or interacting intimately with the membrane surface. Although myelin-specific proteins have been studied for decades, remarkably little is known of their three-dimensional structures. In addition, the exact functions of myelin proteins are to a large extent unknown. In this report, our current knowledge of peripheral nervous system myelin protein structures is reviewed, and the current status of attempts to solve the structures of full-length myelin proteins is evaluated. Furthermore, molecular models for the extracellular domain of the myelin-associated glycoprotein and the putative kinase-like domain of 2',3'-cyclic nucleotide 3'-phosphodiesterase are presented and discussed.

  11. Parametric study of rectangular coil for Eddy Current Testing of lamination

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Peng Fei; Zeng, Zhi Wei [School of Aerospace Engineering, Xiamen University, Xiamen (China)

    2016-04-15

    Eddy current testing (ECT) is an important nondestructive testing technology for the inspection of flaws in conductive materials. However, this widely used technology is not suitable for inspecting lamination when a conventional pancake coil is used because the eddy current (EC) generated by the pancake coil is parallel to the lamination and will not be perturbed. A new method using a rectangular coil placed vertical to the work piece is proposed for lamination detection. The vertical sections of the rectangular coil induce ECs that are vertical to the lamination and can be perturbed by the lamination. A parametric study of a rectangular coil by finite element analysis was performed in order to examine the capability of generating vertical EC sent data 1221-1237.

  12. A Study of Current Land Use in the Urban Area of Ma’anshan City

    Institute of Scientific and Technical Information of China (English)

    Ning ZHANG; Zhongxiang YU

    2016-01-01

    With the acceleration of urbanization,urban development poses a growing demand for land.China’s national conditions of a large population with relatively little arable land require us to intensively use land,and more and more departments have been aware of the importance of intensive urban land use.The study on the current land use in the urban area of Ma’anshan City,is not only conducive to adjustment of land use layout and structure as well as urban ecological construction,but also of guiding significance to the economical and intensive land use in Ma’anshan City.This paper first describes the natural,social and economic situation of Ma’anshan’s urban area,then analyzes the land use structure,layout and problems,and finally puts forth the recommendations for improving current land use situation in the urban area of Ma’anshan City.

  13. Current trends in research and clinical issues in the study of personality and its disorders

    DEFF Research Database (Denmark)

    Simonsen, Erik; Sørensen, Per; Pedersen, Liselotte

    2014-01-01

    lecture (Simonsen), a young researchers' symposium (Hopwood, Sharp, and Kaess), and special lectures on the Danish philosopher Soeren Kierkegaard and the poet Hans Christian Andersen. In this article we will survey the presentations and highlight the important issues in order to underline the current......The International Society for the Study of Personality Disorders (ISSPD) celebrated its 25th anniversary in September 2013 in Copenhagen and commemorated the First International Congress at the same site. The overall theme of the congress was "Bridging Personality and Psychopathology: The Person...... Behind the Illness." More than 400 abstracts were submitted, and the program included 8 keynote presentations, 18 invited symposia, a debate on current controversial issues in the classification of personality disorders (Fossati, Tyrer, Livesley, and Krueger), an ISSPD award lecture (Silk), a jubilee...

  14. Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines

    Directory of Open Access Journals (Sweden)

    Holder Roger L

    2009-07-01

    Full Text Available Abstract Background Multiple imputation (MI provides an effective approach to handle missing covariate data within prognostic modelling studies, as it can properly account for the missing data uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling techniques to obtain the estimates of interest. The estimates from each imputed dataset are then combined into one overall estimate and variance, incorporating both the within and between imputation variability. Rubin's rules for combining these multiply imputed estimates are based on asymptotic theory. The resulting combined estimates may be more accurate if the posterior distribution of the population parameter of interest is better approximated by the normal distribution. However, the normality assumption may not be appropriate for all the parameters of interest when analysing prognostic modelling studies, such as predicted survival probabilities and model performance measures. Methods Guidelines for combining the estimates of interest when analysing prognostic modelling studies are provided. A literature review is performed to identify current practice for combining such estimates in prognostic modelling studies. Results Methods for combining all reported estimates after MI were not well reported in the current literature. Rubin's rules without applying any transformations were the standard approach used, when any method was stated. Conclusion The proposed simple guidelines for combining estimates after MI may lead to a wider and more appropriate use of MI in future prognostic modelling studies.

  15. Anodal transcranial direct current stimulation (tDCS) increases frontal-midline theta activity in the human EEG: a preliminary investigation of non-invasive stimulation.

    Science.gov (United States)

    Miller, Joe; Berger, Barbara; Sauseng, Paul

    2015-02-19

    Rhythmical brain activity in the range between four and eight Hz acquired over frontal-midline EEG recording sites - so called frontal-midline theta activity - is regarded as one of the most prominent neural signatures of sustained attention. It is reported to parametrically increase with cognitive load and is thought to be generated in medial prefrontal cortex. Here we explored the possibility of using anodal transcranial direct current stimulation over frontal sites to enhance frontal-midline theta activity and to increase sustained attention performance. We used a small preliminary sample to test a novel direct current stimulation electrode configuration by which we were able to significantly increase frontal-midline theta amplitude in a resting condition after the end of the stimulation period. Using standardised low resolution electromagnetic tomography analysis the effect in the surface EEG was localised to right prefrontal and left medial prefrontal brain areas. Transcranial direct current stimulation did, however, not have any impact on behavioural performance during a sustained attention task. This most likely was due to a very fast washout of the stimulation's after effect on theta activity. Although these are only preliminary results from a rather small sample, this study demonstrates that transcranial direct current stimulation can be used to rather selectively enhance frontal-midline theta amplitude.

  16. Gene-Environment Interactions in Genome-Wide Association Studies: Current Approaches and New Directions

    Science.gov (United States)

    Winham, Stacey J.; Biernacka, Joanna M.

    2013-01-01

    Background: Complex psychiatric traits have long been thought to be the result of a combination of genetic and environmental factors, and gene-environment interactions are thought to play a crucial role in behavioral phenotypes and the susceptibility and progression of psychiatric disorders. Candidate gene studies to investigate hypothesized…

  17. Passwords Selected by Hospital Employees: An Investigative Study

    Directory of Open Access Journals (Sweden)

    B. Dawn Medlin

    2011-11-01

    Full Text Available The health care industry has benefitted from its employees’ ability to view patient data, but at the same time this access allows for patient’s health care records and information to be easily tampered with or stolen. Access to and transmission of patient data may improve care, increase delivery time of services and reduce health care costs, security of that information may be jeopardized due to the innocent sharing of personal and non-personal data with the wrong person. In this study, we surveyed employees of different size hospitals in various regions of the state who were willing to share their passwords. Our findings indicate that employees need further or additional training in their awareness surrounding password creation.

  18. [A STUDY INVESTIGATING THE FACTORS OF INTERNET ADDICTION].

    Science.gov (United States)

    Puharić, Zrinka; Stašević, Ina; Ropac, Darko; Petričević, Nina; Jurišić, Irena

    2014-12-01

    The aim of the study was to explore the characteristics of Internet use among elementary school eighth-graders in the Bjelo- var-Bilogora County, to evaluate gender and sociodemographic differences, and to examine predictors for Internet addiction. The study included 437 (female 51%) eighth-graders, mean age 13.8 ± 0.5 years. An anonymous questionnaire was used to measure the participants' Internet use, the functions for which they used Internet, their parents' attitude towards the child's Internet use, and their signs of Internet addiction. Logistic regression was conducted to evaluate predictors for Internet addiction. The majority of children (71.5%) reported using Internet every day. Considering important risk factors of Internet addiction development, we found that 32% of children almost always stayed on-line longer than intended, 13% of boys and 4% of girls almost always neglected chores to spend more time on-line and 51.7% of children thought their life would be boring and uninteresting without the Internet. There was no significant difference between urban and rural students. In terms of the function for which they used the Internet, they were mostly engaged in on-line community/chat websites (70%), to listen to music and watch movies (81 %), and boys in gaming websites. Most of the students (43.4%) spent 1-2 hours daily on-line, 26.2% of students spent 3-4 hours on-line, and 9% spent more than 5 hours daily on-line. In conclusion, more public health preventive measures should be conducted to raise public awareness and concern about the negative effect of Internet use and Internet addiction, especially in the young population.

  19. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  20. Study of SEM induced current and voltage contrast modes to assess semiconductor reliability

    Science.gov (United States)

    Beall, J. R.

    1976-01-01

    The purpose of the scanning electron microscopy study was to review the failure history of existing integrated circuit technologies to identify predominant failure mechanisms, and to evaluate the feasibility of their detection using SEM application techniques. The study investigated the effects of E-beam irradiation damage and contamination deposition rates; developed the necessary methods for applying the techniques to the detection of latent defects and weaknesses in integrated circuits; and made recommendations for applying the techniques.

  1. Reducing food wastage, improving food security? An inventory study on stakeholders’ perspectives and the current state

    OpenAIRE

    Tielens, J.; Candel, J.J.L.

    2014-01-01

    This study is concerned with the relation between food wastage reduction and the improvement of food security. The central question of this inventory study is to what extent interventions to reduce food wastage are effective contributions for food security, in particular for local access in developing regions, but also the food system stability in general? To investigate this, an overview of international actors working in the field of wastage has been made, with a European/Dutch focus. Their...

  2. Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, Richard Wayne [ORNL; Eckerman, Keith F [ORNL; Meck, Robert A. [U.S. Nuclear Regulatory Commission

    2008-10-01

    This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intake or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently

  3. Ambient pressure sensitivity of microbubbles investigated through a parameter study

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2009-01-01

    Measurements on microbubbles clearly indicate a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations...... cycles driving pulse, a reduction of 4.6 dB is observed when changing pov from 0 to 25 kPa. Increasing the pulse duration makes the reduction even more clear. For a pulse with 64 cycles, the reduction is 9.9 dB. This simulation is in good correspondence with measurement results presented by Shi et al....... 1999, who found a linear reduction of 9.6 dB. Further simulations of Levovist show that also the shape and the acoustic pressure of the driving pulse are very important factors. The best pressure sensitivity of Levovist was found to be 0.88 dB/kPa. For Sonazoid, a sensitivity of 1.14 dB/kPa has been...

  4. Investigating emotion with music: an fMRI study.

    Science.gov (United States)

    Koelsch, Stefan; Fritz, Thomas; V Cramon, D Yves; Müller, Karsten; Friederici, Angela D

    2006-03-01

    The present study used pleasant and unpleasant music to evoke emotion and functional magnetic resonance imaging (fMRI) to determine neural correlates of emotion processing. Unpleasant (permanently dissonant) music contrasted with pleasant (consonant) music showed activations of amygdala, hippocampus, parahippocampal gyrus, and temporal poles. These structures have previously been implicated in the emotional processing of stimuli with (negative) emotional valence; the present data show that a cerebral network comprising these structures can be activated during the perception of auditory (musical) information. Pleasant (contrasted to unpleasant) music showed activations of the inferior frontal gyrus (IFG, inferior Brodmann's area (BA) 44, BA 45, and BA 46), the anterior superior insula, the ventral striatum, Heschl's gyrus, and the Rolandic operculum. IFG activations appear to reflect processes of music-syntactic analysis and working memory operations. Activations of Rolandic opercular areas possibly reflect the activation of mirror-function mechanisms during the perception of the pleasant tunes. Rolandic operculum, anterior superior insula, and ventral striatum may form a motor-related circuitry that serves the formation of (premotor) representations for vocal sound production during the perception of pleasant auditory information. In all of the mentioned structures, except the hippocampus, activations increased over time during the presentation of the musical stimuli, indicating that the effects of emotion processing have temporal dynamics; the temporal dynamics of emotion have so far mainly been neglected in the functional imaging literature. Copyright 2005 Wiley-Liss, Inc.

  5. Current sedation and monitoring practice for colonoscopy: an International Observational Study (EPAGE)

    DEFF Research Database (Denmark)

    Froehlich, F; Harris, JK; Wietlisbach, V;

    2006-01-01

    in endoscopy centers internationally. PATIENTS AND METHODS: This observational study included consecutive patients referred for colonoscopy at 21 centers in 11 countries. Endoscopists reported sedation and monitoring practice, using a standard questionnaire for each patient. RESULTS: 6004 patients were......BACKGROUND AND STUDY AIMS: Sedation and monitoring practice during colonoscopy varies between centers and over time. Knowledge of current practice is needed to ensure quality of care and help focus future research. The objective of this study was to examine sedation and monitoring practice...... included in this study, of whom 53 % received conscious/moderate sedation during colonoscopy, 30 % received deep sedation, and 17 % received no sedation. Sedation agents most commonly used were midazolam (47 %) and opioids (33 %). Pulse oximetry was done during colonoscopy in 77 % of patients, blood...

  6. Ecology of Urban Bees: A Review of Current Knowledge and Directions for Future Study

    Directory of Open Access Journals (Sweden)

    Gordon W. Frankie

    2009-01-01

    Full Text Available Urban bee ecology is an emerging field that holds promise for advancing knowledge of bee community dynamics and promoting bee conservation. Published studies of bee communities in urban and suburban habitats are fewer than those documenting bees in agricultural and wildland settings. As land lost to urbanization is predicted to increase in coming years the necessity of studying urban bee populations is growing. We reviewed 59 publications on urban bee ecology with the following goals, to assess current knowledge, to highlight areas in need of further research, and to suggest applications of study findings to bee conservation. Identified trends in urban areas included the following, negative correlation between bee species richness and urban development, increase in abundance of cavity-nesters in urban habitats, and scarcity of floral specialists. Future directions for studying urban bee ecology include incorporation of landscape-scale assessments, conducting manipulative experiments and actively designing urban bee habitats.

  7. An advanced phantom study assessing the feasibility of neuronal current imaging by ultra-low-field NMR

    Science.gov (United States)

    Körber, Rainer; Nieminen, Jaakko O.; Höfner, Nora; Jazbinšek, Vojko; Scheer, Hans-Jürgen; Kim, Kiwoong; Burghoff, Martin

    2013-12-01

    In ultra-low-field (ULF) NMR/MRI, a common scheme is to magnetize the sample by a polarizing field of up to hundreds of mT, after which the NMR signal, precessing in a field on the order of several μT, is detected with superconducting quantum interference devices (SQUIDs). In our ULF-NMR system, we polarize with up to 50 mT and deploy a single-stage DC-SQUID current sensor with an integrated input coil which is connected to a wire-wound Nb gradiometer. We developed this system (white noise 0.50 fT/√{Hz}) for assessing the feasibility of imaging neuronal currents by detecting their effect on the ULF-NMR signal. Magnetoencephalography investigations of evoked brain activity showed neuronal dipole moments below 50 nAm. With our instrumentation, we have studied two different approaches for neuronal current imaging. In the so-called DC effect, long-lived neuronal activity shifts the Larmor frequency of the surrounding protons. An alternative strategy is to exploit fast neuronal activity as a tipping pulse. This so-called AC effect requires the proton Larmor frequency to match the frequency of the neuronal activity, which ranges from near-DC to ∼kHz. We emulated neuronal activity by means of a single dipolar source in a physical phantom, consisting of a hollow sphere filled with an aqueous solution of CuSO4 and NaCl. In these phantom studies, with physiologically relevant dipole depths, we determined resolution limits for our set-up for the AC and the DC effect of ∼10 μAm and ∼50 nAm, respectively. Hence, the DC effect appears to be detectable in vivo by current ULF-NMR technology.

  8. Clinical and experimental studies on polyherbal formulations for diabetes:current status and future prospective

    Institute of Scientific and Technical Information of China (English)

    Ahmad Ghorbani

    2014-01-01

    Diabetes is a leading cause of morbidity and mortality in the world. There is currently an active search for antidiabetic drugs with greater effectiveness with fewer and less adverse side effects. Although numerous individual herbs have been experimentally or clinically reported to possess antidiabetic effects, considerably less research has been conducted on polyherbal compounds. It is believed that herbal compounds containing multiple plant products have synergistic antidiabetic effects and could enhance the desired actions. Several polyherbal formulations have been studied as therapeutic agents in diabetes management. To describe the current state of research on polyherbal compounds in the treatment of diabetes, an extensive review of literature was undertaken on several major databases. This paper presents what is known about the efifcacy of these polyherbal formulations and compare their antidiabetic effects with those of current oral hypoglycemic drugs as reference. The percent decrease in blood glucose, lipids and other biochemical parameters achieved by each product in diabetic animals and patients is reported. Also, the possible mechanisms responsible for hypoglycemic action of polyherbal formulations are discussed.

  9. Numerical study on tidal currents and seawater exchange in the Benoa Bay, Bali, Indonesia

    Institute of Scientific and Technical Information of China (English)

    HENDRAWAN I. Gede; ASAI Koji

    2014-01-01

    A three-dimensional (3-D) finite volume coastal ocean model (FVCOM) was used for the study of water cir-culation and seawater exchange in the Benoa Bay, Bali Island. The M2 tidal component was forced in open boundary and discharge from six rivers was included in the numerical calculation. The M2 tidal elevation produced by the FVCOM has a good agreement with the observation data. The M2 tidal current is also suc-cessfully calculated under the ebb tide and flood tide conditions. The non-linear M2 tidal residual current was produced by the coastline geometry, especially surrounding the narrow strait between the Serangan Is-land and the Benoa Peninsula. The tidal residual current also generated two small eddies within the bay and one small eddy in the bay mouth. The salinity distribution influenced by river discharge could be success-fully calculated, where the numerical calculation and the observation results have a good correlation (r2) of 0.75. Finally in order to examine the seawater exchange in the Benoa Bay, the Lagrangian particle tracking method and calculation of residence time are applied. The mechanism of particle transport to the flushing of seawater is depicted clearly by both methods.

  10. A Practical Study of the 66kV Fault Current Limiter (FCL) System with Rectifier

    Science.gov (United States)

    Tokuda, Noriaki; Matsubara, Yoshio; Yuguchi, Kyosuke; Ohkuma, Takeshi; Hobara, Natsuro; Takahashi, Yoshihisa

    A fault current limiter (FCL) is extensively expected to suppress fault current, particularly required for trunk power systems heavily connected high-voltage transmission lines, such as 500kV class power system which constitutes the nucleus of the electric power system. By installing such FCL in the power system, the system interconnection is possible without the need to raise the capacity of the circuit breakers, and facilities can be configured for efficiency, among other benefits. For these reasons, fault current limiters based on various principles of operation have been developed both in Japan and abroad. In this paper, we have proposed a new type of FCL system, consisting of solid-state diodes, DC coil and bypass AC coil, and described the specification of distribution power system and 66kV model at the island power system and the superconducting cable power system. Also we have made a practical study of 66kV class, which is the testing items and the future subjects of the rectifier type FCL system.

  11. Scoping Study Investigating PWR Instrumentation during a Severe Accident Scenario

    Energy Technology Data Exchange (ETDEWEB)

    Rempe, J. L. [Rempe and Associates, LLC, Idaho Falls, ID (United States); Knudson, D. L. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lutz, R. J. [Lutz Nuclear Safety Consultant, LLC, Asheville, NC (United States)

    2015-09-01

    significantly exceeded QE limits for extended time periods for the low frequency STSBO sequence evaluated in this study. It is recognized that the core damage frequency (CDF) of the sequence evaluated in this scoping effort would be considerably lower if evaluations considered new FLEX equipment being installed by industry. Nevertheless, because of uncertainties in instrumentation response when exposed to conditions beyond QE limits and alternate challenges associated with different sequences that may impact sensor performance, it is recommended that additional evaluations of instrumentation performance be completed to provide confidence that operators have access to accurate, relevant, and timely information on the status of reactor systems for a broad range of challenges associated with risk important severe accident sequences.

  12. Microstructural Evolution and Migration Mechanism Study in a Eutectic Sn-37Pb Lap Joint Under High Current Density

    Science.gov (United States)

    Zhang, Zhihao; Cao, Huijun; Yang, Haifeng; Xiao, Yong; Li, Mingyu; Yu, Yuxi; Yao, Shun

    2017-08-01

    The microstructural evolution in eutectic Sn-37Pb solder under high current density seriously threatens the reliability of solder interconnections, but atomic electromigration has often been confused with thermomigration. In this paper, after decoupling the effect of the non-uniform temperature distribution in a Cu/Sn-37Pb/Cu lap joint from the current stress, the microstructural evolution was investigated under an average current density of 1.84 × 104 A cm-2 for 0-24 h. The decomposition and recombination of the Pb-rich phase occurred at the cathode and the anode, respectively. The corresponding migration mechanism was proposed from the viewpoint of energy and was explained by the interactions among the potential energies of ripening, electron wind force, and back stress. Our study may be helpful for understanding the migration mechanism and reliability of eutectic two-phase solder joints and provides supporting data for interpreting the acceleration tests of Sn-37Pb solder joints under electromigration.

  13. Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves

    Science.gov (United States)

    Charland, Jenna; Touboul, Julien; Rey, Vincent

    2013-04-01

    Wave propagation against current : a study of the effects of vertical shears of the mean current on the geometrical focusing of water waves J. Charland * **, J. Touboul **, V. Rey ** jenna.charland@univ-tln.fr * Direction Générale de l'Armement, CNRS Délégation Normandie ** Université de Toulon, 83957 La Garde, France Mediterranean Institute of Oceanography (MIO) Aix Marseille Université, 13288 Marseille, France CNRS/INSU, IRD, MIO, UM 110 In the nearshore area, both wave propagation and currents are influenced by the bathymetry. For a better understanding of wave - current interactions in the presence of a 3D bathymetry, a large scale experiment was carried out in the Ocean Basin FIRST, Toulon, France. The 3D bathymetry consisted of two symmetric underwater mounds on both sides in the mean wave direction. The water depth at the top the mounds was hm=1,5m, the slopes of the mounds were of about 1:3, the water depth was h=3 m elsewhere. For opposite current conditions (U of order 0.30m/s), a huge focusing of the wave up to twice its incident amplitude was observed in the central part of the basin for T=1.4s. Since deep water conditions are verified, the wave amplification is ascribed to the current field. The mean velocity fields at a water depth hC=0.25m was measured by the use of an electromagnetic current meter. The results have been published in Rey et al [4]. The elliptic form of the "mild slope" equation including a uniform current on the water column (Chen et al [1]) was then used for the calculations. The calculated wave amplification of factor 1.2 is significantly smaller than observed experimentally (factor 2). So, the purpose of this study is to understand the physical processes which explain this gap. As demonstrated by Kharif & Pelinovsky [2], geometrical focusing of waves is able to modify significantly the local wave amplitude. We consider this process here. Since vertical velocity profiles measured at some locations have shown significant

  14. Current Situation Investigation of the Interactive Classroom Teaching (Ⅲ)%互动式课堂教学现状的调查(Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    张亚; 王翀; 易龙; 廖晓兰

    2013-01-01

    A form of questionnaire by investigation was carried out to study the current situation of interactive class-room teaching in order to improve the quality of talent fosterage. The results showed that many teachers believed that the interest and intelligence of the students were the most important factors for interactive classroom teaching;second-ly, students'attitude towards study and individual mood may also affect the results of interactive classroom teaching. In respect of requirements for teachers in teacher-student interaction, 27% of students believed that teachers should be rigorous and methodical, 24% thought that teachers should be humorous, wit and concentrative, 13% considered teachers should be erudite, while 36% believed that teachers should not only be rigorous, humour and wit, and eru-dite, but also should have fairly strong capability of synthesis. When investigating the interactive role of teachers and students, 68% of teachers believed both teachers and students need mutual efforts, 16% of teachers thought it laid stress on teachers, 15% of teachers considered students should set store on, and some individual chose others. In ad-dition, when investigating the form of teacher-student interaction, 35% of students believed“the setting scene” work best results in classroom interaction, 28% considered that the effect of “debate competition” interaction will result well, 21% selected the style of “asking student by naming him or her” interaction, only a few students chose “visi-tors'book” as interaction. The results of this investigation provided references for universities and colleges to carry out interactive mode of teaching reformation.%为加强课堂教学改革,提高人才培养质量,采取问卷调查的形式对互动式课堂教学现状进行了研究。结果表明:多数教师认为学生的兴趣和智力是影响师生互动的重要因素,其次学习态度和个人情绪也会影响互动式课堂教学效果;在

  15. Nonlinear effects on western boundary current structure and separation: a laboratory study

    Science.gov (United States)

    Pierini, S.; Falco, P.; Zambardino, G.; McClimans, T. A.; Ellingsen, I.

    2009-04-01

    The role played by nonlinear effects in shaping the structure of barotropic western boundary currents (WBCs) and in determining WBC separation from the coast has been investigated through laboratory simulations by means of the 5-m-diameter Coriolis rotating basin at SINTEF (Trondheim, Norway) in the framework of the HYDRALAB-III project. The laboratory setup consists of two parallel rectangular channels separated by an island and linked by two curved connections: in the first channel, a piston is forced at a constant speed U ranging from 0.05 to 3 cm/s over a distance of 2.5 m, producing a virtually unsheared current at the entrance of the second channel. In the latter, a linear reduction of the water depth provides the topographic beta-effect that produces the westward intensification. Nearly steady currents are obtained and measured photogrammetrically over a region of about 1 m2. The broad range of piston speeds permitted by the mechanical apparatus has allowed us to achieve an unprecedented coverage of the range of nonlinearity for WBCs in terms of experimental data, so that the cross-stream WBC profile could be analyzed from the nearly linear Munk-type case (e.g., for U=0.1 cm/s with T=30 s, where T is the rotation period of the basin) up to the more realistic highly nonlinear limit (particularly significant is the case U=1 cm/s and T=30 s, which is close to be dynamically similar to the Gulf Stream). Thanks to the large size of the rotating basin, cross-stream widths of the simulated WBC as large as 80 cm could be obtained. Moreover, in order to analyze the process of WBC separation, coastal variations have been introduced along the western boundary in the form of wedge-shaped continents with different coastline orientations, whose northern limit corresponds to an idealized Cape Hatteras. While weak WBCs follow the coast also past the cape, for sufficiently strong nonlinear effects the current detaches from the coast as a consequence of flow deceleration

  16. Catalog of Completed Studies, US Army Health Care Studies and Clinical Investigation Activity.

    Science.gov (United States)

    1984-12-10

    Environment Substudy: AD A139001 Effects of Chemical Protective Clothing on the Performance of Basic Medical Tasks (HCSD Report #83-001) 8 DATE TITLE...Contact urticaria to parabens , Arch. Dermatol, 1979, 115:1231-1232. *13 Smith, E. B., Padilla, R. S., McCabe, J. M., Becker, L. E., Benzoyl...Chemical Environment . --3-Report #83-001. Ft. Sam Houston, TX: Health Care Studies and Clinical Investigation Activity, December 1982. 19 Penetar, D. M

  17. Motivated Attention to Cocaine and Emotional Cues in Abstinent and Current Cocaine Users: An ERP Study

    Science.gov (United States)

    Dunning, Jonathan P.; Parvaz, Muhammad A.; Hajcak, Greg; Maloney, Thomas; Alia-Klein, Nelly; Woicik, Patricia A.; Telang, Frank; Wang, Gene-Jack; Volkow, Nora D.; Goldstein, Rita Z.

    2011-01-01

    Event-related potentials (ERPs) are a direct measure of neural activity and are ideally suited to study the time-course of attentional engagement with emotional and drug-related stimuli in addiction. In particular, the late positive potential (LPP) appears enhanced following cocaine-related compared to neutral stimuli in individuals with cocaine use disorders (CUD). However, previous studies have not directly compared cocaine-related to emotional stimuli while examining potential differences between abstinent and current cocaine users. The present study examined ERPs in 55 CUD (27 abstinent and 28 current users) and 29 matched healthy controls while they passively viewed pleasant, unpleasant, neutral, and cocaine-related pictures. To examine the time-course of attention to these stimuli, we analyzed both an early and later window in the LPP as well as the early posterior negativity (EPN), established in assessing motivated attention. Cocaine pictures elicited increased electrocortical measures of motivated attention in ways similar to affectively pleasant and unpleasant pictures in all CUD, an effect that was no longer discernible during the late LPP window for the current users. This group also exhibited deficient processing of the other emotional stimuli (early LPP window: pleasant pictures; late LPP window: pleasant and unpleasant pictures). Results were unique to the LPP and not EPN. Taken together, results support a relatively early attention bias to cocaine stimuli in cocaine addicted individuals further suggesting that recent cocaine use decreases such attention bias during later stages of processing but at the expense of deficient processing of other emotional stimuli. PMID:21450043

  18. Accelerating Virtual High-Throughput Ligand Docking: current technology and case study on a petascale supercomputer.

    Science.gov (United States)

    Ellingson, Sally R; Dakshanamurthy, Sivanesan; Brown, Milton; Smith, Jeremy C; Baudry, Jerome

    2014-04-25

    In this paper we give the current state of high-throughput virtual screening. We describe a case study of using a task-parallel MPI (Message Passing Interface) version of Autodock4 [1], [2] to run a virtual high-throughput screen of one-million compounds on the Jaguar Cray XK6 Supercomputer at Oak Ridge National Laboratory. We include a description of scripts developed to increase the efficiency of the predocking file preparation and postdocking analysis. A detailed tutorial, scripts, and source code for this MPI version of Autodock4 are available online at http://www.bio.utk.edu/baudrylab/autodockmpi.htm.

  19. Electromagnetic and beam dynamics studies of a high current drift tube linac for LEHIPA

    Science.gov (United States)

    Roy, S.; Rao, S. V. L. S.; Pande, R.; Krishnagopal, S.; Singh, P.

    2014-06-01

    We have performed detailed electromagnetic and beam dynamics studies of a 352.21 MHz drift-tube linac (DTL) that will accelerate a 30 mA CW proton beam from 3 to 20 MeV. At such high currents space charge effects are important, and therefore the effect of linear as well as non-linear space charge has been studied (corresponding to uniform and Gaussian initial beam distributions), in order to avoid space charge instabilities. To validate the electromagnetic simulations, a 1.2 m long prototype of the DTL was fabricated. RF measurements performed on the prototype were in good agreement with the simulations. A detailed simulation study of beam halos was also performed, which showed that beyond a current of 10 mA, significant longitudinal beam halos are excited even for a perfectly matched beam, whereas for a mis-matched beam transverse beam halos are also excited. However, these do not lead to any beam loss within the DTL.

  20. Study of a new direct current atmospheric pressure glow discharge in helium

    Energy Technology Data Exchange (ETDEWEB)

    Gielniak, B. [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Fiedler, T. [Johannes Gutenberg-University Mainz, Institute for Inorganic and Analytical Chemistry, Duesbergweg 10-14, 55128 Mainz (Germany); Broekaert, J.A.C., E-mail: jose.broekaert@chemie.uni-hamburg.de [University of Hamburg, Institute for Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany)

    2011-01-15

    In this study a new DC-APGD operated in He was developed and characterized. The discharge is operated at 0.9 kV and about 25-35 mA and at a gas flow of 100 ml/min. The source was spectroscopically studied and parameters such as the rotational temperature (T{sub rot}), the excitation temperature (T{sub exc}), the ionization temperature (T{sub ion}) and the electron number density (n{sub e}) were determined. The current-voltage characteristic of the source was studied as well. At optimized conditions the discharge operates in the normal region of the current-voltage characteristic. Rotational and excitation temperatures determined with the use of OH band and Fe I lines as thermometric species were of the order of about 900-1200 and 4500-5500 K, respectively. This indicates that despite of the atmospheric pressure, the discharge is not in LTE. Spatially resolved temperature measurements were performed with axial as well as radial resolution and showed relatively flat profiles. Axially resolved emission intensity profiles for several species such as H, N{sub 2}, N{sub 2}{sup +}, OH, He and Hg were determined. It also was found that H{sub 2} introduced into the He by electrolysis of acid solutions such as in ECHG considerably increases the spectroscopically measured gas temperatures but decreases the analyte line intensities, as shown for Hg.

  1. Large A.C. machines theory and investigation methods of currents and losses in stator and rotor meshes including operation with nonlinear loads

    CERN Document Server

    Boguslawsky, Iliya; Hayakawa, Masashi

    2017-01-01

    In this monograph the authors solve the modern scientific problems connected with A.C. motors and generators, based first on the detailed consideration of their physical phenomena. The authors describe the theory and investigative methods they developed and applied in practice, which are considered to be of essential interest for specialists in the field of the electrical engineering industry in European countries, the USA, Argentina, and Brazil, as well as in such countries as India, China, and Iran. This book will be of interest to engineers specialized in the field of the manufacture, operation, and repair of A.C. machines (motors and generators) as well as electric drives; to professors, lecturers, and post-graduate students of technical universities, who are specializing in the field of electric machine engineering and electric drives; and to students who are engaged in the field of high current techniques, electric drives, and electric machine engineering.

  2. Investigation of chemical vapour deposition diamond detectors by X- ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    CERN Document Server

    Olivero, P; Vittone, E; Fizzotti, F; Paolini, C; Lo Giudice, A; Barrett, R; Tucoulou, R

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the Large Hadron Collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro- beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitati...

  3. An investigation of the role of the time averaged ion beam current density upon the defect densities in thin film SIMOX

    Science.gov (United States)

    Nejim, A.; Marsh, C. D.; Giles, L. F.; Hemment, P. L. F.; Li, Y.; Chater, RJ.; Kilner, J. A.; Booker, G. R.

    1994-02-01

    The effect of the time averaged ion beam current density on the material quality of thin film SIMOX has been investigated. Thin film SOI/SIMOX material has been produced by 200 keV oxygen implantation into 3 in. Fz wafers with a background temperature of 680°C. The dose range of 5 × 10 17-7 × 10 17O+/ cm2 was selected to be near the dose threshold for the formation of a continuous buried oxide after implantation and annealing which is thought to be between 5 × 10 17 and 6 × 10 17 O +/cm 2 for 200 keV [A.E. White et al., Appl. Phys. Lett. 50 (1987) 19; P.L.F. Hemment et al., Vacuum 36 (1986) 877; Y. Li et al., in: Proc. V Int. Symp. on SOI Technology and Devices (The Electrochemical Society, 1992) p. 368 [1-3

  4. Investigation of band offsets and direct current leakage properties of nitrogen doped epitaxial Gd{sub 2}O{sub 3} thin films on Si

    Energy Technology Data Exchange (ETDEWEB)

    Roy Chaudhuri, Ayan; Osten, H. J. [Institute of Electronic Materials and Devices, Leibniz University of Hannover, Schneiderberg 32, D-30167 Hannover (Germany); Fissel, A. [Information Technology Laboratory, Leibniz University of Hannover, Schneiderberg 32, D-30167 Hannover (Germany)

    2013-05-14

    Dielectric properties of epitaxial Gd{sub 2}O{sub 3} thin films grown on Si have been found to improve significantly by incorporation of suitable dopants. However, in order to achieve optimum electrical properties from such doped oxides, it is important to understand the correlation between doping and the electronic structure of the material. In the present article, we report about the effect of nitrogen doping on the electronic structure and room temperature dc leakage properties of epitaxial Gd{sub 2}O{sub 3} thin films. Epitaxial Gd{sub 2}O{sub 3}:N thin films were grown on p-type Si (111) substrates by solid source molecular beam epitaxy technique using molecular N{sub 2}O as the nitridation agent. First investigations confirmed the presence of substitutional N in the Gd{sub 2}O{sub 3}:N layers. Incorporation of nitrogen did not affect the structural quality of the oxide layers. X ray photoelectron spectroscopy investigations revealed band gap narrowing in epitaxial Gd{sub 2}O{sub 3} due to nitrogen doping, which leads to reduction in the valence band offset of the Gd{sub 2}O{sub 3}:N layers with Si. DC leakage current measured at room temperature revealed that despite reduction in the band gap and valence band offsets due to N doping, the Gd{sub 2}O{sub 3}:N layers remain sufficiently insulating. A significant reduction of the leakage current densities in the Gd{sub 2}O{sub 3}:N layers with increasing nitrogen content suggests that doping of epitaxial Gd{sub 2}O{sub 3} thin films with nitrogen can be an effective route to eliminate the adverse effects of the oxygen vacancy induced defects in the oxide layers.

  5. Studies on the Effect of Column Angle in Figure-8 Centrifugal Counter-current Chromatography

    Science.gov (United States)

    Yang, Yi; Gu, Dongyu; Aisa, Haji Akber; Ito, Yoichiro

    2010-01-01

    The performance of the figure-8 column configuration in centrifugal counter-current chromatography was investigated by changing the angle between the column axis (a line through the central post and the peripheral post on which the figure-8 coil is wound) and the centrifugal force. The first series of experiments was performed using a polar two-phase solvent system composed of 1-butanol-acetic acid-water (4:1:5, v/v) to separate two dipeptide samples, Trp-Tyr and Val-Tyr, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was changed from 0° (column axis parallel to the centrifugal force) to 45° and 45° to 90° (column axis perpendicular to the centrifugal force), peak resolution (Rs) changed from 1.93 (Sf = 37.8%) to 1.54 (Sf=30.6%), then to 1.31 (Sf = 40.5%) with the lower mobile phase and from 1.21 (Sf = 38.8%) to 1.10 (Sf =34.4%), then to 0.99 (Sf = 42.2%) with the upper mobile phase, respectively, where the stationary phase retention, Sf, is given in parentheses. The second series of experiments was similarly performed with a more hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1M hydrochloric acid (1:1:1:1, v/v) to separate three DNP-amino acids, DNP-glu, DNP-α-ala and DNP-ala, at a flow rate of 0.05 ml/min at 1000 rpm. When the column angle was altered from 0° to 45° and 45° to 90°, Rs changed from 1.77 (1st peak/ 2nd peak) and 1.52 (2nd peak/3rd peak) (Sf = 27.3%) to 1.24 and 1.02 (Sf = 35.4%), then to 1.69 and 1.49 (Sf = 42.1%) with the lower mobile phase, and from 1.73 and 0.84 (SF = 41.2%) to 1.44 and 0.73 (Sf = 45.6%), then to 1.21 and 0.63 (Sf = 55.6%) with the upper mobile phase, respectively. The performance of figure-8 column at 0° and 90° was also compared at different flow rates. The results show that Rs was increased with decreased flow rate yielding the highest value at the 0° column angle with lower mobile phase. The overall results of our studies indicated that a 0° column angle for the

  6. Malassezia: Estado del conocimiento y perspectivas en su estudio Malassezia: Current knowledge and study perspectives

    Directory of Open Access Journals (Sweden)

    Gustavo E. Giusiano

    2006-03-01

    knowledge of the ecology and epidemiology of this genus. Noteworthy antifungal susceptibility variations have been observed in some species, although there is not a standard method for these yeasts. There are few data about their biochemical characteristics, and the enzymes they produce might be important virulence factors, favouring host tissue invasion. Malassezia has been recognised as a member of the normal human and animal skin. Its implication in pathologic processes, including skin diseases to systemic infections, is the main issue in current investigations in order to determine the real pathogenic role of these yeasts.

  7. Current meter data from moored current meter casts in the Coastal Waters of S. Alaska as part of the Fisheries-Oceanography Cooperative Investigations (FOCI) project from 21 August 1984 - 01 July 1985 (NCEI Accession 8700053)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter data were collected using moored current meter casts in the Coastal Waters of S. Alaska from August 21, 1984 to July 1, 1985. Data were submitted by...

  8. Physical, current, and other data from CTD and current meters from FIXED PLATFORMS in the Bering Sea in support of the Fisheries-Oceanography Coordinated Investigations (FOCI) project from 25 February 1998 to 10 October 2001 (NODC Accession 0000665)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, current, and other data from CTD and current meters from FIXED PLATFORMS in the Bering Sea from 25 February 1998 to 10 October 2001. Data were collected by...

  9. Current meter and pressure gauge data from moored current meter casts and other instruments in the Gulf of Alaska as part of the Fisheries-Oceanography Cooperative Investigations (FOCI) project, 26 April 1989 - 26 September 1989 (NODC Accession 9100068)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current meter and pressure gauge data were collected using moored current meter casts and other instruments in the Gulf of Alaska from April 22, 1989 to September...

  10. Effect of Direct Electricity Current on Viability of Leishmania (L tropica Promastigotes: an in vitro Study

    Directory of Open Access Journals (Sweden)

    M Malek

    2016-01-01

    Full Text Available Introduction: Leishmaniasis is among top ten infectious diseases in the world, including the three diseases is important that the development of vaccines, medicines and insecticides is difficult to control it. The aim of in this study was Effect of direct electricity current on viability of Leishmania (L tropica promastigotes: an In vitro study. Methods: Leishmania (L tropica [MHOM / IR / NADIM3] to an appropriate level in NNN medium and RPMI1640 culture and promastigotes was prepared both stationary and logarithmic phases. The effects of the direct current from the electrodes 2 or 4 cm Leishmania parasite when staining the size of 1 × 1/5 cm in a arose gel and the parasites create both stationary and logarithmic phases were separate. Electrodes are 2 or 4 cm, and when the voltage in the order of 2/5, 3/5 and 4/5 was applied to the electrodes at 5, 10, 15, 20, 25, 30, 35 and 70 minutes.   Results: Mean number of live promastigotes stationary and logarithmic stages when the distance between the electrodes was 2 cm to voltage 2/5, 3/5 and 4/5 compared with promastigotes in the control group showed significant differences (P=0.003. Also mean number of live promastigotes static stage when the distance between the electrodes was 4 cm to voltage 2/5 and 3/5 V was not significant (P=0.148. And 3/5 and 4/5 volts for voltage are not significant (P>0.05, the mean number of live promastigotes logarithmic stage when the distance between the electrodes was 4 cm, the voltage difference between the number of parasites for 2/5 and 3/5 V  Not significant (P=0.725. Conclusion: The electrodes are more sensitive and dynamic stage promastigotes lower and higher voltage electric current effect on growth control well.

  11. Current debates on end-of-life sedation: an international expert elicitation study.

    Science.gov (United States)

    Papavasiliou, Evangelia Evie; Payne, Sheila; Brearley, Sarah

    2014-08-01

    End-of-life sedation, though increasingly prevalent and widespread internationally, remains one of the most highly debated medical practices in the context of palliative medicine. This qualitative study aims to elicit and record the perspectives of leading international palliative care experts on current debates. Twenty-one professionals from diverse backgrounds, sharing field-specific knowledge/expertise defined by significant scholarly contribution on end-of-life sedation, were recruited. Open-ended, semi-structured interviews, following a topic-oriented structure reflecting on current debates, were conducted. Results were analysed using thematic content analysis. Three main aspects of sedation were identified and discussed as potentially problematic: (a) continuous deep sedation as an extreme facet of end-of-life sedation, (b) psycho-existential suffering as an ambivalent indication for sedation and (c) withdrawal or withholding of artificial nutrition and hydration as potentially life-shortening. On these grounds, concerns were reported over end-of-life sedation being morally equivalent to euthanasia. Considerable emphasis was placed on intentions as the distinguishing factor between end-of-life acts, and protective safeguards were introduced to distance sedation from euthanasia. This study shows that, despite the safeguards introduced, certain aspects of sedation, including the intentions associated with the practice, are still under question, parallels being drawn between end-of-life sedation and euthanasia. This reaffirms the existence of a grey area surrounding the two practices, already evidenced in countries where euthanasia is legalized. More clarity over the issues that generate this grey area, with their causes being uncovered and eliminated, is imperative to resolve current debates and effectively inform research, policy and practice of end-of-life sedation.

  12. Ion Current Density Study of the NASA-300M and NASA-457Mv2 Hall Thrusters

    Science.gov (United States)

    Huang, Wensheng; Shastry, Rohit; Herman, Daniel A.; Soulas, George C.; Kamhawi, Hani

    2012-01-01

    NASA Glenn Research Center is developing a Hall thruster in the 15-50 kW range to support future NASA missions. As a part of the process, the performance and plume characteristics of the NASA-300M, a 20-kW Hall thruster, and the NASA-457Mv2, a 50-kW Hall thruster, were evaluated. The collected data will be used to improve the fidelity of the JPL modeling tool, Hall2De, which will then be used to aid the design of the 15-50 kW Hall thruster. This paper gives a detailed overview of the Faraday probe portion of the plume characterization study. The Faraday probe in this study is a near-field probe swept radially at many axial locations downstream of the thruster exit plane. Threshold-based integration limits with threshold values of 1/e, 1/e(sup 2), and 1/e(sup 3) times the local peak current density are tried for the purpose of ion current integration and divergence angle calculation. The NASA-300M is operated at 7 conditions and the NASA-457Mv2 at 14 conditions. These conditions span discharge voltages of 200 to 500 V and discharge power of 10 to 50 kW. The ion current density profiles of the near-field plume originating from the discharge channel are discovered to strongly resemble Gaussian distributions. A novel analysis approach involving a form of ray tracing is used to determine an effective point of origin for the near-field plume. In the process of performing this analysis, definitive evidence is discovered that showed the near-field plume is bending towards the thruster centerline.

  13. Meta-studies in land use science: Current coverage and prospects.

    Science.gov (United States)

    van Vliet, Jasper; Magliocca, Nicholas R; Büchner, Bianka; Cook, Elizabeth; Rey Benayas, José M; Ellis, Erle C; Heinimann, Andreas; Keys, Eric; Lee, Tien Ming; Liu, Jianguo; Mertz, Ole; Meyfroidt, Patrick; Moritz, Mark; Poeplau, Christopher; Robinson, Brian E; Seppelt, Ralf; Seto, Karen C; Verburg, Peter H

    2016-02-01

    Land use science has traditionally used case-study approaches for in-depth investigation of land use change processes and impacts. Meta-studies synthesize findings across case-study evidence to identify general patterns. In this paper, we provide a review of meta-studies in land use science. Various meta-studies have been conducted, which synthesize deforestation and agricultural land use change processes, while other important changes, such as urbanization, wetland conversion, and grassland dynamics have hardly been addressed. Meta-studies of land use change impacts focus mostly on biodiversity and biogeochemical cycles, while meta-studies of socioeconomic consequences are rare. Land use change processes and land use change impacts are generally addressed in isolation, while only few studies considered trajectories of drivers through changes to their impacts and their potential feedbacks. We provide a conceptual framework for linking meta-studies of land use change processes and impacts for the analysis of coupled human-environmental systems. Moreover, we provide suggestions for combining meta-studies of different land use change processes to develop a more integrated theory of land use change, and for combining meta-studies of land use change impacts to identify tradeoffs between different impacts. Land use science can benefit from an improved conceptualization of land use change processes and their impacts, and from new methods that combine meta-study findings to advance our understanding of human-environmental systems.

  14. Drug interaction studies on new drug applications: current situations and regulatory views in Japan.

    Science.gov (United States)

    Nagai, Naomi

    2010-01-01

    Drug interaction studies on new drug applications (NDAs) for new molecular entities (NMEs) approved in Japan between 1997 and 2008 are examined in the Pharmaceuticals and Medical Devices Agency (PMDA). The situations of drug interaction studies in NDAs have changed over the past 12 years, especially in metabolizing enzyme and transporter-based drug interactions. Materials and approaches to study drug-metabolizing enzyme-based drug interactions have improved, and become more rational based on mechanistic theory and new technologies. On the basis of incremental evidence of transporter roles in human pharmacokinetics, transporter-based drug interactions have been increasingly studied during drug development and submitted in recent NDAs. Some recently approved NMEs include transporter-based drug interaction information in their package inserts (PIs). The regulatory document "Methods of Drug Interaction Studies," in addition to recent advances in science and technology, has also contributed to plan and evaluation of drug interaction studies in recent new drug development. This review summarizes current situations and further discussion points on drug interaction studies in NDAs in Japan.

  15. Data Integrity-A Study of Current Regulatory Thinking and Action.

    Science.gov (United States)

    Shafiei, Nader; De Montardy, Regis; Rivera-Martinez, Edwin

    2015-01-01

    In reaction to breaches of data integrity in the pharmaceutical industry, regulatory authorities have introduced inspection approaches or initiatives with the aim of reducing occurrences of data integrity problems. This review article-based on study of 65 cases of regulatory action from 2002 to 2014-provides an overview of current regulatory thinking and action on breaches of data integrity affecting GxP (health-related regulations) processes supporting non-clinical studies, clinical studies, laboratory controls, and production controls. These case studies largely represent position of the U.S. Food and Drug Administration and the regulatory agencies affiliated with the European Medicines Agency. Also discussed is the role of human factors as a potential source of data integrity problems. The article concludes by recommending some remedial controls that could be established to avoid or reduce occurrences of data integrity problems.Lay Abstract: In fulfilling their mission to protect public health, regulatory agencies (e.g., U.S. Food and Drug Administration, European Medicines Agency) must establish confidence that medical products they approve are fit for their intended use. In so doing they rely on scientific and operational data generated during research, development, manufacturing, sales, marketing, distribution, and post-marketing surveillance activities. The level of confidence they build is directly proportional to the scientific validity and integrity of data presented to them by the sponsors of medical products. In this article we present analysis of 65 case studies that document regulatory action taken by various regulatory agencies on breach of data integrity between 2002 and 2014. The ensuing discussion on current trends largely represents position of the U.S. Food and Drug Administration and European Medicines Agency. The article concludes by proposing some remedial controls that could be established by pharmaceutical companies to avoid or reduce

  16. Numerical and experimental study of the interaction between two marine current turbines

    CERN Document Server

    Mycek, Paul; Germain, Grégory; Pinon, Grégory; Rivoalen, Elie

    2013-01-01

    The understanding of interaction effects between marine energy converters represents the next step in the research process that should eventually lead to the deployment of such devices. Although some a priori considerations have been suggested recently, very few real condition studies have been carried out concerning this issue. Trials were run on 1/30th scale models of three-bladed marine current turbine prototypes in a flume tank. The present work focuses on the case where a turbine is placed at different locations in the wake of a first one. The interaction effects in terms of performance and wake of the second turbine are examined and compared to the results obtained on the case of one single turbine. Besides, a three-dimensional software, based on a vortex method is currently being developed, and will be used in the near future to model more complex layouts. The experimental study shows that the second turbine is deeply affected by the presence of an upstream device and that a compromise between individu...

  17. MREIT experiments with 200 µA injected currents: a feasibility study using two reconstruction algorithms, SMM and harmonic B(Z).

    Science.gov (United States)

    Arpinar, V E; Hamamura, M J; Degirmenci, E; Muftuler, L T

    2012-07-07

    Magnetic resonance electrical impedance tomography (MREIT) is a technique that produces images of conductivity in tissues and phantoms. In this technique, electrical currents are applied to an object and the resulting magnetic flux density is measured using magnetic resonance imaging (MRI) and the conductivity distribution is reconstructed using these MRI data. Currently, the technique is used in research environments, primarily studying phantoms and animals. In order to translate MREIT to clinical applications, strict safety standards need to be established, especially for safe current limits. However, there are currently no standards for safe current limits specific to MREIT. Until such standards are established, human MREIT applications need to conform to existing electrical safety standards in medical instrumentation, such as IEC601. This protocol limits patient auxiliary currents to 100 µA for low frequencies. However, published MREIT studies have utilized currents 10-400 times larger than this limit, bringing into question whether the clinical applications of MREIT are attainable under current standards. In this study, we investigated the feasibility of MREIT to accurately reconstruct the relative conductivity of a simple agarose phantom using 200 µA total injected current and tested the performance of two MREIT reconstruction algorithms. These reconstruction algorithms used are the iterative sensitivity matrix method (SMM) by Ider and Birgul (1998 Elektrik 6 215-25) with Tikhonov regularization and the harmonic B(Z) proposed by Oh et al (2003 Magn. Reason. Med. 50 875-8). The reconstruction techniques were tested at both 200 µA and 5 mA injected currents to investigate their noise sensitivity at low and high current conditions. It should be noted that 200 µA total injected current into a cylindrical phantom generates only 14.7 µA current in imaging slice. Similarly, 5 mA total injected current results in 367 µA in imaging slice. Total

  18. Age at menarche and current substance use among Canadian adolescent girls: results of a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Al-Sahab Ban

    2012-03-01

    Full Text Available Abstract Background Substance use is among the key public health threats that find its genesis during adolescence. Timing of puberty has been lately researched as a potential predictor of subsequent substance abuse. The present study, therefore, aims to assess the effect of age at menarche on current practices of smoking, alcohol drinking and drug use among 14-15 year old Canadian girls. Methods The analysis of the study was based on all female respondents aged 14 to 15 years during Cycle 4 (2000/2001 of the National Longitudinal Survey of Children & Youth (NLSCY. The main independent variable was age at menarche assessed as the month and year of the occurrence of the first menstrual cycle. The dependent variables were current smoking, heavy alcohol drinking in the past 12 months and drug use in the past 12 months. Three logistic regression models were performed to investigate the association between age at menarche and each of the substance use outcomes, adjusting for possible confounders. Bootstrapping was performed to account for the complex sampling design. Results The total weighted sample included in the analysis represented 295,042 Canadian girls. The prevalence of current smokers, heavy drinkers (drunk in the past 12 months and drug users in the past 12 months was approximately 22%, 38% and 26%, respectively. After adjusting of all potential confounders, no association was found between age at menarche and any of the substance use outcomes. School performance and relationship with the father, however, stood out as the main variables to be associated with smoking, heavy drinking and drug use. Conclusions Qualitative studies understanding the social and psychological changes experienced by early maturing Canadian adolescents are warranted to identify other correlates or pathways to substance use in this higher risk population.

  19. General aspects and current view of the molecular study of Phenylketonuria (PKU in Mexico

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Alcántara-Ortigoza

    2014-07-01

    Full Text Available Phenylketonuria (PKU is an autosomic recessive inborn errors of metabolism. It is caused y the deficiency of phenylalanine hydroxylase, an enzyme encoded by the PAH gene in 12q22. This gene has a wide mutation spectrum and several different genotypes have been identified. There are many experimental strategies that allow molecular diagnosis of PAH in order to identify causal mutations in patients with phenylektonuria. The identification of the PAH genotype in these patients allows genetic counseling, genotype-phenotype correlation and for some cases treatment adjustment. There are few studies concerning the mutation spectrum of PAH in Mexican patients. Currently, a study to identify the genotypes of these patients is being done. Only preliminary results are presented, nevertheless results are expected to clarify the mutation spectrum, enable the identification of possible genotype-phenotype correlations and elucidate the ancestral origin of the mutations.

  20. Structural, Optical, and Dielectric Investigations of the Relaxor PLZT 9,75/65/35 Ceramics Irradiated by High-Current Pulsed Electron Beam

    CERN Document Server

    Efimov, V V; Kalmikov, A V; Klevtsova, E A; Minashkin, V F; Novikova, N N; Sikolenko, V V; Skripnik, A V; Sternberg, A; Tiutiunnikov, S I; Yakovlev, V A

    2002-01-01

    First time comprehensive study of high-current pulsed electron irradiation effects on the structural, optical and dielectric properties of relaxor (Pb_{(1-x)}La^{x}(Zr_{0.65}Ti_{0.35})_{1-x/4}O_{3} ceramics with x=9.75% has been provided. The electron beam had the following parameters: energy E_{e}=250 keV, current density J_{e}=1000 A/cm^{2}, pulse duration tau = 300 ns, density 10^{15} electrons/cm^{2} per pulse. Infrared reflectivity spectra in the region of 100-2000 cm^{-1} were obtained in virgin, irradiated by 1500 pulses and annealed up to t=500^{circ}C ceramics. The reconstruction of perovskite ABO_{3} structure in irradiated samples has been studied by complex use of X-ray and neutron scattering and IR spectroscopy techniques revealing the changes in transverse and longitudinal phonon modes, oscillators strength and damping of modes. Radiation effects on temperature behaviour of dielectric permittivity in the region of phase transition were studied. The possible mechanisms of pulsed electron irradiat...