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Sample records for time-intervals reveal electrostatic

  1. Membrane Protein Properties Revealed through Data-Rich Electrostatics Calculations.

    Science.gov (United States)

    Marcoline, Frank V; Bethel, Neville; Guerriero, Christopher J; Brodsky, Jeffrey L; Grabe, Michael

    2015-08-04

    The electrostatic properties of membrane proteins often reveal many of their key biophysical characteristics, such as ion channel selectivity and the stability of charged membrane-spanning segments. The Poisson-Boltzmann (PB) equation is the gold standard for calculating protein electrostatics, and the software APBSmem enables the solution of the PB equation in the presence of a membrane. Here, we describe significant advances to APBSmem, including full automation of system setup, per-residue energy decomposition, incorporation of PDB2PQR, calculation of membrane-induced pKa shifts, calculation of non-polar energies, and command-line scripting for large-scale calculations. We highlight these new features with calculations carried out on a number of membrane proteins, including the recently solved structure of the ion channel TRPV1 and a large survey of 1,614 membrane proteins of known structure. This survey provides a comprehensive list of residues with large electrostatic penalties for being embedded in the membrane, potentially revealing interesting functional information. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Early diastolic time intervals during hypertensive pregnancy.

    Science.gov (United States)

    Spinelli, L; Ferro, G; Nappi, C; Farace, M J; Talarico, G; Cinquegrana, G; Condorelli, M

    1987-10-01

    Early diastolic time intervals have been assessed by means of the echopolycardiographic method in 17 pregnant women who developed hypertension during pregnancy (HP) and in 14 normal pregnant women (N). Systolic time intervals (STI), stroke volume (SV), ejection fraction (EF), and mean velocity of myocardial fiber shortening (VCF) were also evaluated. Recordings were performed in the left lateral decubitus (LLD) and then in the supine decubitus (SD). In LLD, isovolumic relaxation period (IRP) was prolonged in the hypertensive pregnant women compared with normal pregnant women (HP 51 +/- 12.5 ms, N 32.4 +/- 15 ms p less than 0.05), whereas time of the mitral valve maximum opening (DE) was not different in the groups. There was no difference in SV, EF, and mean VCF, whereas STI showed only a significant (p less than 0.05) lengthening of pre-ejection period (PEP) in HP. When the subjects shifted from the left lateral to the supine decubitus position, left ventricular ejection time index (LVETi) and SV decreased significantly (p less than 0.05) in both normotensive hypertensive pregnant women. IRP and PEP lengthened significantly (p less than 0.05) only in normals, whereas they were unchanged in HP. DE time did not vary in either group. In conclusion, hypertension superimposed on pregnancy induces lengthening of IRP, as well as of PEP, and minimizes the effects of the postural changes in preload on the above-mentioned time intervals.

  3. Electrostatic point charge fitting as an inverse problem: Revealing the underlying ill-conditioning

    International Nuclear Information System (INIS)

    Ivanov, Maxim V.; Talipov, Marat R.; Timerghazin, Qadir K.

    2015-01-01

    Atom-centered point charge (PC) model of the molecular electrostatics—a major workhorse of the atomistic biomolecular simulations—is usually parameterized by least-squares (LS) fitting of the point charge values to a reference electrostatic potential, a procedure that suffers from numerical instabilities due to the ill-conditioned nature of the LS problem. To reveal the origins of this ill-conditioning, we start with a general treatment of the point charge fitting problem as an inverse problem and construct an analytical model with the point charges spherically arranged according to Lebedev quadrature which is naturally suited for the inverse electrostatic problem. This analytical model is contrasted to the atom-centered point-charge model that can be viewed as an irregular quadrature poorly suited for the problem. This analysis shows that the numerical problems of the point charge fitting are due to the decay of the curvatures corresponding to the eigenvectors of LS sum Hessian matrix. In part, this ill-conditioning is intrinsic to the problem and is related to decreasing electrostatic contribution of the higher multipole moments, that are, in the case of Lebedev grid model, directly associated with the Hessian eigenvectors. For the atom-centered model, this association breaks down beyond the first few eigenvectors related to the high-curvature monopole and dipole terms; this leads to even wider spread-out of the Hessian curvature values. Using these insights, it is possible to alleviate the ill-conditioning of the LS point-charge fitting without introducing external restraints and/or constraints. Also, as the analytical Lebedev grid PC model proposed here can reproduce multipole moments up to a given rank, it may provide a promising alternative to including explicit multipole terms in a force field

  4. Unpacking a time interval lengthens its perceived temporal distance

    Directory of Open Access Journals (Sweden)

    Yang eLiu

    2014-11-01

    Full Text Available In quantity estimation, people often perceive that the whole is less than the sum of its parts. The current study investigated such an unpacking effect in temporal distance judgment. Our results showed that participants in the unpacked condition judged a given time interval longer than those in the packed condition, even the time interval was kept constant between the two conditions. Furthermore, this unpacking effect persists regardless of the unpacking ways we employed. Results suggest that unpacking a time interval may be a good strategy for lengthening its perceived temporal distance.

  5. Time interval approach to the pulsed neutron logging method

    International Nuclear Information System (INIS)

    Zhao Jingwu; Su Weining

    1994-01-01

    The time interval of neighbouring neutrons emitted from a steady state neutron source can be treated as that from a time-dependent neutron source. In the rock space, the neutron flux is given by the neutron diffusion equation and is composed of an infinite terms. Each term s composed of two die-away curves. The delay action is discussed and used to measure the time interval with only one detector in the experiment. Nuclear reactions with the time distribution due to different types of radiations observed in the neutron well-logging methods are presented with a view to getting the rock nuclear parameters from the time interval technique

  6. Foundation for a Time Interval Access Control Model

    National Research Council Canada - National Science Library

    Afinidad, Francis B; Levin, Timothy E; Irvine, Cynthia E; Nguyen, Thuy D

    2005-01-01

    A new model for representing temporal access control policies is introduced. In this model, temporal authorizations are represented by time attributes associated with both subjects and objects, and a time interval access graph...

  7. Timing intervals using population synchrony and spike timing dependent plasticity

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2016-12-01

    Full Text Available We present a computational model by which ensembles of regularly spiking neurons can encode different time intervals through synchronous firing. We show that a neuron responding to a large population of convergent inputs has the potential to learn to produce an appropriately-timed output via spike-time dependent plasticity. We explain why temporal variability of this population synchrony increases with increasing time intervals. We also show that the scalar property of timing and its violation at short intervals can be explained by the spike-wise accumulation of jitter in the inter-spike intervals of timing neurons. We explore how the challenge of encoding longer time intervals can be overcome and conclude that this may involve a switch to a different population of neurons with lower firing rate, with the added effect of producing an earlier bias in response. Experimental data on human timing performance show features in agreement with the model’s output.

  8. Infinite time interval backward stochastic differential equations with continuous coefficients.

    Science.gov (United States)

    Zong, Zhaojun; Hu, Feng

    2016-01-01

    In this paper, we study the existence theorem for [Formula: see text] [Formula: see text] solutions to a class of 1-dimensional infinite time interval backward stochastic differential equations (BSDEs) under the conditions that the coefficients are continuous and have linear growths. We also obtain the existence of a minimal solution. Furthermore, we study the existence and uniqueness theorem for [Formula: see text] [Formula: see text] solutions of infinite time interval BSDEs with non-uniformly Lipschitz coefficients. It should be pointed out that the assumptions of this result is weaker than that of Theorem 3.1 in Zong (Turkish J Math 37:704-718, 2013).

  9. Hybrid integrated circuit for charge-to-time interval conversion

    Energy Technology Data Exchange (ETDEWEB)

    Basiladze, S.G.; Dotsenko, Yu.Yu.; Man' yakov, P.K.; Fedorchenko, S.N. (Joint Inst. for Nuclear Research, Dubna (USSR))

    The hybrid integrated circuit for charge-to time interval conversion with nanosecond input fast response is described. The circuit can be used in energy measuring channels, time-to-digital converters and in the modified variant in amplitude-to-digital converters. The converter described consists of a buffer amplifier, a linear transmission circuit, a direct current source and a unit of time interval separation. The buffer amplifier represents a current follower providing low input and high output resistances by the current feedback. It is concluded that the described converter excelled the QT100B circuit analogous to it in a number of parameters especially, in thermostability.

  10. Cardiac Time Intervals by Tissue Doppler Imaging M-Mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; de Knegt, Martina Chantal

    2016-01-01

    PURPOSE: To define normal values of the cardiac time intervals obtained by tissue Doppler imaging (TDI) M-mode through the mitral valve (MV). Furthermore, to evaluate the association of the myocardial performance index (MPI) obtained by TDI M-mode (MPITDI) and the conventional method of obtaining...

  11. Discriminator/time interval meter system evaluation report

    International Nuclear Information System (INIS)

    Condreva, K.J.

    1976-01-01

    The purpose of this report is to discuss the evaluation of a modular prototype Discriminator/Time Interval Meter data acquisition unit as a useful tool in a digital diagnostics system. The characteristics, operation and calibration of each of the hardware components are discussed in some detail. A discussion of the system calibration, operation, and data ingestion and reduction is also given. System test results to date are given and discussed. Finally, recommendations and conclusions concerning the capabilities of the Discriminator/T.I.M. system based on test and calibration results to date are given

  12. Discriminator/time interval meter system evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Condreva, K. J.

    1976-04-12

    The purpose of this report is to discuss the evaluation of a modular prototype Discriminator/Time Interval Meter data acquisition unit as a useful tool in a digital diagnostics system. The characteristics, operation and calibration of each of the hardware components are discussed in some detail. A discussion of the system calibration, operation, and data ingestion and reduction is also given. System test results to date are given and discussed. Finally, recommendations and conclusions concerning the capabilities of the Discriminator/T.I.M. system based on test and calibration results to date are given.

  13. Time interval measurement between two emissions: Ar + Au

    International Nuclear Information System (INIS)

    Bizard, G.; Bougault, R.; Brou, R.; Buta, A.; Durand, D.; Genoux-Lubain, A.; Hamdani, T.; Horn, D.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Louvel, M.; Peter, J.; Regimbart, R.; Steckmeyer, J.C.; Tamain, B.

    1998-01-01

    The Ar + Au system was studied at two bombarding energies, 30 and 60 A.MeV. The comparison of the distributions of fragment emission angles in central collisions was carried out by means of a simulation allowing the emission time interval variation. It was found that this interval depends on the bombarding energy (i.e. deposed excitation energy).For 30 A.MeV this interval is 500 fm/c (0.33 · 10 -23 s), while for 60 A.MeV it is so short that the multifragmentation concept can be used

  14. Optimal time interval for induction of immunologic adaptive response

    International Nuclear Information System (INIS)

    Ju Guizhi; Song Chunhua; Liu Shuzheng

    1994-01-01

    The optimal time interval between prior dose (D1) and challenge dose (D2) for the induction of immunologic adaptive response was investigated. Kunming mice were exposed to 75 mGy X-rays at a dose rate of 12.5 mGy/min. 3, 6, 12, 24 or 60 h after the prior irradiation the mice were challenged with a dose of 1.5 Gy at a dose rate of 0.33 Gy/min. 18h after D2, the mice were sacrificed for examination of immunological parameters. The results showed that with an interval of 6 h between D1 and D2, the adaptive response of the reaction of splenocytes to LPS was induced, and with an interval of 12 h the adaptive responses of spontaneous incorporation of 3 H-TdR into thymocytes and the reaction of splenocytes to Con A and LPS were induced with 75 mGy prior irradiation. The data suggested that the optimal time intervals between D1 and D2 for the induction of immunologic adaptive response were 6 h and 12 h with a D1 of 75 mGy and a D2 of 1.5 Gy. The mechanism of immunologic adaptation following low dose radiation is discussed

  15. Time interval measurement between to emission: a systematics

    International Nuclear Information System (INIS)

    Bizard, G.; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Mahi, M.; Meslin, C.; Steckmeyer, J.C.; Tamain, B.; Wieloch, A.

    1998-01-01

    A systematic study of the evolution of intervals of fragment emission times as a function of the energy deposited in the compound system was performed. Several measurements, Ne at 60 MeV/u, Ar at 30 and 60 MeV/u and two measurements for Kr at 60 MeV/u (central and semi-peripheral collisions) are presented. In all the experiments the target was Au and the mass of the compounds system was around A = 200. The excitation energies per nucleon reached in the case of these heavy systems cover the range of 3 to 5.5 MeV/u. The method used to determine the emission time intervals is based on the correlation functions associated to the relative angle distributions. The gaps between the data and simulations allow to evaluate the emission times. A rapid decrease of these time intervals was observed when the excitation energy increased. This variation starts at 500 fm/c which corresponds to a sequential emission. This relatively long time which indicates a weak interaction between fragments, corresponds practically to the measurement threshold. The shortest intervals (about 50 fm/c) are associated to a spontaneous multifragmentation and were observed in the case of central collisions at Ar+Au and Kr+Au at 60 MeV/u. Two interpretations are possible. The multifragmentation process might be viewed as a sequential process of very short time-separation or else, one can separate two zones heaving in mind that the multifragmentation is predominant from 4,5 MeV/u excitation energy upwards. This question is still open and its study is under way at LPC. An answer could come from the study of the rupture process of an excited nucleus, notably by the determination of its life-time

  16. Non-Native Metal Ion Reveals the Role of Electrostatics in Synaptotagmin 1-Membrane Interactions.

    Science.gov (United States)

    Katti, Sachin; Nyenhuis, Sarah B; Her, Bin; Srivastava, Atul K; Taylor, Alexander B; Hart, P John; Cafiso, David S; Igumenova, Tatyana I

    2017-06-27

    C2 domains are independently folded modules that often target their host proteins to anionic membranes in a Ca 2+ -dependent manner. In these cases, membrane association is triggered by Ca 2+ binding to the negatively charged loop region of the C2 domain. Here, we used a non-native metal ion, Cd 2+ , in lieu of Ca 2+ to gain insight into the contributions made by long-range Coulombic interactions and direct metal ion-lipid bridging to membrane binding. Using X-ray crystallography, NMR, Förster resonance energy transfer, and vesicle cosedimentation assays, we demonstrate that, although Cd 2+ binds to the loop region of C2A/B domains of synaptotagmin 1 with high affinity, long-range Coulombic interactions are too weak to support membrane binding of individual domains. We attribute this behavior to two factors: the stoichiometry of Cd 2+ binding to the loop regions of the C2A and C2B domains and the impaired ability of Cd 2+ to directly coordinate the lipids. In contrast, electron paramagnetic resonance experiments revealed that Cd 2+ does support membrane binding of the C2 domains in full-length synaptotagmin 1, where the high local lipid concentrations that result from membrane tethering can partially compensate for lack of a full complement of divalent metal ions and specific lipid coordination in Cd 2+ -complexed C2A/B domains. Our data suggest that long-range Coulombic interactions alone can drive the initial association of C2A/B with anionic membranes and that Ca 2+ further augments membrane binding by the formation of metal ion-lipid coordination bonds and additional Ca 2+ ion binding to the C2 domain loop regions.

  17. Design of time interval generator based on hybrid counting method

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yuan [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Wang, Zhaoqi [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Lu, Houbing [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Hefei Electronic Engineering Institute, Hefei 230037 (China); Chen, Lian [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Jin, Ge, E-mail: goldjin@ustc.edu.cn [State Key Laboratory of Particle Detection and Electronics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

    2016-10-01

    Time Interval Generators (TIGs) are frequently used for the characterizations or timing operations of instruments in particle physics experiments. Though some “off-the-shelf” TIGs can be employed, the necessity of a custom test system or control system makes the TIGs, being implemented in a programmable device desirable. Nowadays, the feasibility of using Field Programmable Gate Arrays (FPGAs) to implement particle physics instrumentation has been validated in the design of Time-to-Digital Converters (TDCs) for precise time measurement. The FPGA-TDC technique is based on the architectures of Tapped Delay Line (TDL), whose delay cells are down to few tens of picosecond. In this case, FPGA-based TIGs with high delay step are preferable allowing the implementation of customized particle physics instrumentations and other utilities on the same FPGA device. A hybrid counting method for designing TIGs with both high resolution and wide range is presented in this paper. The combination of two different counting methods realizing an integratable TIG is described in detail. A specially designed multiplexer for tap selection is emphatically introduced. The special structure of the multiplexer is devised for minimizing the different additional delays caused by the unpredictable routings from different taps to the output. A Kintex-7 FPGA is used for the hybrid counting-based implementation of a TIG, providing a resolution up to 11 ps and an interval range up to 8 s.

  18. Design of time interval generator based on hybrid counting method

    International Nuclear Information System (INIS)

    Yao, Yuan; Wang, Zhaoqi; Lu, Houbing; Chen, Lian; Jin, Ge

    2016-01-01

    Time Interval Generators (TIGs) are frequently used for the characterizations or timing operations of instruments in particle physics experiments. Though some “off-the-shelf” TIGs can be employed, the necessity of a custom test system or control system makes the TIGs, being implemented in a programmable device desirable. Nowadays, the feasibility of using Field Programmable Gate Arrays (FPGAs) to implement particle physics instrumentation has been validated in the design of Time-to-Digital Converters (TDCs) for precise time measurement. The FPGA-TDC technique is based on the architectures of Tapped Delay Line (TDL), whose delay cells are down to few tens of picosecond. In this case, FPGA-based TIGs with high delay step are preferable allowing the implementation of customized particle physics instrumentations and other utilities on the same FPGA device. A hybrid counting method for designing TIGs with both high resolution and wide range is presented in this paper. The combination of two different counting methods realizing an integratable TIG is described in detail. A specially designed multiplexer for tap selection is emphatically introduced. The special structure of the multiplexer is devised for minimizing the different additional delays caused by the unpredictable routings from different taps to the output. A Kintex-7 FPGA is used for the hybrid counting-based implementation of a TIG, providing a resolution up to 11 ps and an interval range up to 8 s.

  19. Time interval measurement between two emissions: Kr + Au

    International Nuclear Information System (INIS)

    Aboufirassi, M; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Mahi, M.; Steckmeyer, J.C.; Tamain, B.

    1998-01-01

    To indicate the method allowing the determination of the emission intervals, the results obtained with the Kr + Au system at 43 and 60 A.MeV are presented. The experiments were performed with the NAUTILUS exclusive detectors. Central collisions were selected by means of a relative velocity criterion to reject the events containing a forward emitted fragment. For the two bombardment energies the data analysis shows that the formation of a compound of mass around A = 200. By comparing the fragment dynamical variables with simulations one can conclude about the simultaneity of the compound deexcitation processes. It was found that a 5 MeV/A is able to reproduce the characteristics of the detected fragments. Also, it was found that to reproduce the dynamical characteristics of the fragments issued from central collisions it was not necessary to superimpose a radial collective energy upon the Coulomb and thermal motion. The distribution of the relative angles between detected fragments is used here as a chronometer. For simultaneous ruptures the small relative angles are forbidden by the Coulomb repulsion, while for sequential processes this interdiction is the more lifted the longer the interval between the two emissions is. For the system discussed here the comparison between simulation and data has been carried out for the extreme cases, i.e. for a vanishing and infinite time interval between the two emissions, respectively. More sophisticated simulations to describe angular distributions between the emitted fragments were also developed

  20. Revealing energy level structure of individual quantum dots by tunneling rate measured by single-electron sensitive electrostatic force spectroscopy.

    Science.gov (United States)

    Roy-Gobeil, Antoine; Miyahara, Yoichi; Grutter, Peter

    2015-04-08

    We present theoretical and experimental studies of the effect of the density of states of a quantum dot (QD) on the rate of single-electron tunneling that can be directly measured by electrostatic force microscopy (e-EFM) experiments. In e-EFM, the motion of a biased atomic force microscope cantilever tip modulates the charge state of a QD in the Coulomb blockade regime. The charge dynamics of the dot, which is detected through its back-action on the capacitavely coupled cantilever, depends on the tunneling rate of the QD to a back-electrode. The density of states of the QD can therefore be measured through its effect on the energy dependence of tunneling rate. We present experimental data on individual 5 nm colloidal gold nanoparticles that exhibit a near continuous density of state at 77 K. In contrast, our analysis of already published data on self-assembled InAs QDs at 4 K clearly reveals discrete degenerate energy levels.

  1. Structural Snapshots of an Engineered Cystathionine-γ-lyase Reveal the Critical Role of Electrostatic Interactions in the Active Site

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Wupeng; Stone, Everett; Zhang, Yan Jessie

    2017-02-01

    Enzyme therapeutics that can degrade l-methionine (l-Met) are of great interest as numerous malignancies are exquisitely sensitive to l-Met depletion. To exhaust the pool of methionine in human serum, we previously engineered an l-Met-degrading enzyme based on the human cystathionine-γ-lyase scaffold (hCGL-NLV) to circumvent immunogenicity and stability issues observed in the preclinical application of bacterially derived methionine-γ-lyases. To gain further insights into the structure–activity relationships governing the chemistry of the hCGL-NLV lead molecule, we undertook a biophysical characterization campaign that captured crystal structures (2.2 Å) of hCGL-NLV with distinct reaction intermediates, including internal aldimine, substrate-bound, gem-diamine, and external aldimine forms. Curiously, an alternate form of hCGL-NLV that crystallized under higher-salt conditions revealed a locally unfolded active site, correlating with inhibition of activity as a function of ionic strength. Subsequent mutational and kinetic experiments pinpointed that a salt bridge between the phosphate of the essential cofactor pyridoxal 5'-phosphate (PLP) and residue R62 plays an important role in catalyzing β- and γ-eliminations. Our study suggests that solvent ions such as NaCl disrupt electrostatic interactions between R62 and PLP, decreasing catalytic efficiency.

  2. A comparison between brachial and echocardiographic systolic time intervals.

    Directory of Open Access Journals (Sweden)

    Ho-Ming Su

    Full Text Available Systolic time interval (STI is an established noninvasive technique for the assessment of cardiac function. Brachial STIs can be automatically determined by an ankle-brachial index (ABI-form device. The aims of this study are to evaluate whether the STIs measured from ABI-form device can represent those measured from echocardiography and to compare the diagnostic values of brachial and echocardiographic STIs in the prediction of left ventricular ejection fraction (LVEF <50%. A total of 849 patients were included in the study. Brachial pre-ejection period (bPEP and brachial ejection time (bET were measured using an ABI-form device and pre-ejection period (PEP and ejection time (ET were measured from echocardiography. Agreement was assessed by correlation coefficient and Bland-Altman plot. Brachial STIs had a significant correlation with echocardiographic STIs (r = 0.644, P<0.001 for bPEP and PEP; r  = 0.850, P<0.001 for bET and ET; r = 0.708, P<0.001 for bPEP/bET and PEP/ET. The disagreement between brachial and echocardiographic STIs (brachial STIs minus echocardiographic STIs was 28.55 ms for bPEP and PEP, -4.15 ms for bET and ET and -0.11 for bPEP/bET and PEP/ET. The areas under the curve for bPEP/bET and PEP/ET in the prediction of LVEF <50% were 0.771 and 0.765, respectively. Brachial STIs were good alternatives to STIs obtained from echocardiography and also helpful in prediction of LVEF <50%. Brachial STIs automatically obtained from an ABI-form device may be helpful for evaluation of left ventricular systolic dysfunction.

  3. New precession expressions, valid for long time intervals

    Science.gov (United States)

    Vondrák, J.; Capitaine, N.; Wallace, P.

    2011-10-01

    Context. The present IAU model of precession, like its predecessors, is given as a set of polynomial approximations of various precession parameters intended for high-accuracy applications over a limited time span. Earlier comparisons with numerical integrations have shown that this model is valid only for a few centuries around the basic epoch, J2000.0, while for more distant epochs it rapidly diverges from the numerical solution. In our preceding studies we also obtained preliminary developments for the precessional contribution to the motion of the equator: coordinates X,Y of the precessing pole and precession parameters ψA,ωA, suitable for use over long time intervals. Aims: The goal of the present paper is to obtain upgraded developments for various sets of precession angles that would fit modern observations near J2000.0 and at the same time fit numerical integration of the motions of solar system bodies on scales of several thousand centuries. Methods: We used the IAU 2006 solutions to represent the precession of the ecliptic and of the equator close to J2000.0 and, for more distant epochs, a numerical integration using the Mercury 6 package and solutions by Laskar et al. (1993, A&A, 270, 522) with upgraded initial conditions and constants to represent the ecliptic, and general precession and obliquity, respectively. From them, different precession parameters were calculated in the interval ± 200 millennia from J2000.0, and analytical expressions are found that provide a good fit for the whole interval. Results: Series for the various precessional parameters, comprising a cubic polynomial plus from 8 to 14 periodic terms, are derived that allow precession to be computed with an accuracy comparable to IAU 2006 around the central epoch J2000.0, a few arcseconds throughout the historical period, and a few tenths of a degree at the ends of the ± 200 millennia time span. Computer algorithms are provided that compute the ecliptic and mean equator poles and the

  4. Systolic time intervals vs invasive predictors of fluid responsiveness after coronary artery bypass surgery(dagger)

    NARCIS (Netherlands)

    Smorenberg, A.; Lust, E.J.; Beishuizen, A.; Meijer, J.H.; Verdaasdonk, R.M.; Groeneveld, A.B.J.

    2013-01-01

    OBJECTIVES: Haemodynamic parameters for predicting fluid responsiveness in intensive care patients are invasive, technically challenging or not universally applicable. We compared the initial systolic time interval (ISTI), a non-invasive measure of the time interval between the electrical and

  5. Department of Defense Precise Time and Time Interval program improvement plan

    Science.gov (United States)

    Bowser, J. R.

    1981-01-01

    The United States Naval Observatory is responsible for ensuring uniformity in precise time and time interval operations including measurements, the establishment of overall DOD requirements for time and time interval, and the accomplishment of objectives requiring precise time and time interval with minimum cost. An overview of the objectives, the approach to the problem, the schedule, and a status report, including significant findings relative to organizational relationships, current directives, principal PTTI users, and future requirements as currently identified by the users are presented.

  6. Continuous time modelling with individually varying time intervals for oscillating and non-oscillating processes.

    Science.gov (United States)

    Voelkle, Manuel C; Oud, Johan H L

    2013-02-01

    When designing longitudinal studies, researchers often aim at equal intervals. In practice, however, this goal is hardly ever met, with different time intervals between assessment waves and different time intervals between individuals being more the rule than the exception. One of the reasons for the introduction of continuous time models by means of structural equation modelling has been to deal with irregularly spaced assessment waves (e.g., Oud & Delsing, 2010). In the present paper we extend the approach to individually varying time intervals for oscillating and non-oscillating processes. In addition, we show not only that equal intervals are unnecessary but also that it can be advantageous to use unequal sampling intervals, in particular when the sampling rate is low. Two examples are provided to support our arguments. In the first example we compare a continuous time model of a bivariate coupled process with varying time intervals to a standard discrete time model to illustrate the importance of accounting for the exact time intervals. In the second example the effect of different sampling intervals on estimating a damped linear oscillator is investigated by means of a Monte Carlo simulation. We conclude that it is important to account for individually varying time intervals, and encourage researchers to conceive of longitudinal studies with different time intervals within and between individuals as an opportunity rather than a problem. © 2012 The British Psychological Society.

  7. Time-to-code converter with selection of time intervals on duration

    International Nuclear Information System (INIS)

    Atanasov, I.Kh.; Rusanov, I.R.; )

    2001-01-01

    Identification of elementary particles on the basis of time-of-flight represents the important approach of the preliminary selection procedure. Paper describes a time-to-code converter with preliminary selection of the measured time intervals as to duration. It consists of a time-to-amplitude converter, an analog-to-digital converter, a unit of selection of time intervals as to duration, a unit of total reset and CAMAC command decoder. The time-to-code converter enables to measure time intervals with 100 ns accuracy within 0-100 ns range. Output code capacity is of 10. Selection time constitutes 50 ns [ru

  8. Efficient Estimation for Diffusions Sampled at High Frequency Over a Fixed Time Interval

    DEFF Research Database (Denmark)

    Jakobsen, Nina Munkholt; Sørensen, Michael

    Parametric estimation for diffusion processes is considered for high frequency observations over a fixed time interval. The processes solve stochastic differential equations with an unknown parameter in the diffusion coefficient. We find easily verified conditions on approximate martingale...

  9. The Time Is Up: Compression of Visual Time Interval Estimations of Bimodal Aperiodic Patterns

    Science.gov (United States)

    Duarte, Fabiola; Lemus, Luis

    2017-01-01

    The ability to estimate time intervals subserves many of our behaviors and perceptual experiences. However, it is not clear how aperiodic (AP) stimuli affect our perception of time intervals across sensory modalities. To address this question, we evaluated the human capacity to discriminate between two acoustic (A), visual (V) or audiovisual (AV) time intervals of trains of scattered pulses. We first measured the periodicity of those stimuli and then sought for correlations with the accuracy and reaction times (RTs) of the subjects. We found that, for all time intervals tested in our experiment, the visual system consistently perceived AP stimuli as being shorter than the periodic (P) ones. In contrast, such a compression phenomenon was not apparent during auditory trials. Our conclusions are: first, the subjects exposed to P stimuli are more likely to measure their durations accurately. Second, perceptual time compression occurs for AP visual stimuli. Lastly, AV discriminations are determined by A dominance rather than by AV enhancement. PMID:28848406

  10. Quantification of transuranic elements by time interval correlation spectroscopy of the detected neutrons

    Science.gov (United States)

    Baeten; Bruggeman; Paepen; Carchon

    2000-03-01

    The non-destructive quantification of transuranic elements in nuclear waste management or in safeguards verifications is commonly performed by passive neutron assay techniques. To minimise the number of unknown sample-dependent parameters, Neutron Multiplicity Counting (NMC) is applied. We developed a new NMC-technique, called Time Interval Correlation Spectroscopy (TICS), which is based on the measurement of Rossi-alpha time interval distributions. Compared to other NMC-techniques, TICS offers several advantages.

  11. The importance of time interval to development of second tumor in metachronous bilateral wilms' tumor

    International Nuclear Information System (INIS)

    Paulino, Arnold C.; Thakkar, Bharat; Henderson, William G.

    1997-01-01

    Purpose: To determine whether the time interval to development of second tumor is a prognostic factor for overall survival in children with metachronous bilateral Wilms' tumor and to give a recommendation regarding screening of the contralateral kidney in patients with Wilms' tumor. Materials and Management: A literature search using MEDLINE was performed of manuscripts in the English language from 1950-1996 and identified 108 children with metachronous bilateral Wilms' tumor. Children were classified according to time interval to development of a contralateral Wilms' tumor ( 78 mos (2), 78 - < 84 mos (1), 84 - < 90 mos (0), 90 - < 96 mos (1), ≥ 96 mos (0). Analysis of overall survival in patients with a time interval of < 18 months and ≥ 18 months showed a 10 year survival of 39.6% and 55.2%, respectively (p = 0.024, log-rank test). Conclusions: Children with metachronous bilateral Wilms' tumor who develop a contralateral tumor at a time interval of ≥ 18 months from the initial Wilms' tumor had a better overall survival than children with a time interval of < 18 months. Screening by abdominal ultrasound of the contralateral kidney for more than 5 years after initial diagnosis of Wilms' tumor may not be necessary since 102/106 (96.2%) of children had a time interval to second tumor of < 60 months

  12. Perceptual inequality between two neighboring time intervals defined by sound markers: correspondence between neurophysiological and psychological data

    Directory of Open Access Journals (Sweden)

    Takako eMitsudo

    2014-09-01

    Full Text Available Brain activity related to time estimation processes in humans was analyzed using a perceptual phenomenon called auditory temporal assimilation. In a typical stimulus condition, two neighboring time intervals (T1 and T2 in this order are perceived as equal even when the physical lengths of these time intervals are considerably different. Our previous event-related potential (ERP study demonstrated that a slow negative component (SNCt appears in the right-frontal brain area (around the F8 electrode after T2, which is associated with judgment of the equality/inequality of T1 and T2. In the present study, we conducted two ERP experiments to further confirm the robustness of the SNCt. The stimulus patterns consisted of two neighboring time intervals marked by three successive tone bursts. Thirteen participants only listened to the patterns in the first session, and judged the equality/inequality of T1 and T2 in the next session. Behavioral data showed typical temporal assimilation. The ERP data revealed that three components (N1; contingent negative variation, CNV; and SNCt emerged related to the temporal judgment. The N1 appeared in the central area, and its peak latencies corresponded to the physical timing of each marker onset. The CNV component appeared in the frontal area during T2 presentation, and its amplitude increased as a function of T1. The SNCt appeared in the right-frontal area after the presentation of T1 and T2, and its magnitude was larger for the temporal patterns causing perceptual inequality. The SNCt was also correlated with the perceptual equality/inequality of the same stimulus pattern, and continued up to about 400 ms after the end of T2. These results suggest that the SNCt can be a signature of equality/inequality judgment, which derives from the comparison of the two neighboring time intervals.

  13. Characterization of Cardiac Time Intervals in Healthy Bonnet Macaques (Macaca radiata) by Using an Electronic Stethoscope

    Science.gov (United States)

    Kamran, Haroon; Salciccioli, Louis; Pushilin, Sergei; Kumar, Paraag; Carter, John; Kuo, John; Novotney, Carol; Lazar, Jason M

    2011-01-01

    Nonhuman primates are used frequently in cardiovascular research. Cardiac time intervals derived by phonocardiography have long been used to assess left ventricular function. Electronic stethoscopes are simple low-cost systems that display heart sound signals. We assessed the use of an electronic stethoscope to measure cardiac time intervals in 48 healthy bonnet macaques (age, 8 ± 5 y) based on recorded heart sounds. Technically adequate recordings were obtained from all animals and required 1.5 ± 1.3 min. The following cardiac time intervals were determined by simultaneously recording acoustic and single-lead electrocardiographic data: electromechanical activation time (QS1), electromechanical systole (QS2), the time interval between the first and second heart sounds (S1S2), and the time interval between the second and first sounds (S2S1). QS2 was correlated with heart rate, mean arterial pressure, diastolic blood pressure, and left ventricular ejection time determined by using echocardiography. S1S2 correlated with heart rate, mean arterial pressure, diastolic blood pressure, left ventricular ejection time, and age. S2S1 correlated with heart rate, mean arterial pressure, diastolic blood pressure, systolic blood pressure, and left ventricular ejection time. QS1 did not correlate with any anthropometric or echocardiographic parameter. The relation S1S2/S2S1 correlated with systolic blood pressure. On multivariate analyses, heart rate was the only independent predictor of QS2, S1S2, and S2S1. In conclusion, determination of cardiac time intervals is feasible and reproducible by using an electrical stethoscope in nonhuman primates. Heart rate is a major determinant of QS2, S1S2, and S2S1 but not QS1; regression equations for reference values for cardiac time intervals in bonnet macaques are provided. PMID:21439218

  14. Coronary angiography after successful thrombolysis - Is the recommended time interval of 24h an important issue?

    Science.gov (United States)

    Costa, Cátia; Durão, David; Belo, Adriana; Domingues, Kevin; Santos, Beatriz; Leal, Margarida

    2016-11-01

    Percutaneous coronary intervention (PCI) is currently considered the gold-standard treatment of acute coronary syndromes with ST-segment elevation (STEMI). However, this is not the reality of many European centers, where thrombolysis is performed as primary therapy. To determine, in a STEMI population that performed successful fibrinolytic treatment, if the performance of coronary angiography after the first 24h was associated with more hospital complications, including higher mortality, compared with its performance in the recommended time. Retrospective study, including 1065 patients with STEMI, who performed successful thrombolysis. The population was divided in three groups: A, patients who didn't undergo coronary angiography after successful thrombolysis (n=278; 26.1%); B, patients who underwent coronary angiography in the first 24h after successful thrombolysis (n=127; 11.9%); and C, patients who underwent angiography after the first 24h (n=660; 62.0%). Groups were compared regarding their characteristics and in-hospital complications. Groups B and C had more male patients and had younger patients than group A. Group A presented higher Killip classes at admission, more severe left ventricle dysfunction and a higher number of complications during hospitalization. Logistic regression revealed that: 1) the non-performance of coronary angiography after thrombolysis was an independent predictor of in-hospital mortality; and 2) the performance of angiography after the recommended time wasn't associated with higher mortality. Coronary angiography after thrombolysis constitutes an important strategy, whose non-performance carries worse prognosis. The time interval currently recommended of 24h seems clinically acceptable; however, its realization outside the recommended time doesn't seem to lead to higher mortality. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Cardiac time intervals by tissue Doppler imaging M-mode echocardiography

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor

    2016-01-01

    for myocardial myocytes to achieve an LV pressure equal to that of aorta increases, resulting in a prolongation of the isovolumic contraction time (IVCT). Furthermore, the ability of myocardial myocytes to maintain the LV pressure decreases, resulting in reduction in the ejection time (ET). As LV diastolic...... of whether the LV is suffering from impaired systolic or diastolic function. A novel method of evaluating the cardiac time intervals has recently evolved. Using tissue Doppler imaging (TDI) M-mode through the mitral valve (MV) to estimate the cardiac time intervals may be an improved method reflecting global...

  16. A comparison of systolic time intervals measured by impedance cardiography and carotid pulse tracing

    DEFF Research Database (Denmark)

    Mehlsen, J; Bonde, J; Rehling, Michael

    1990-01-01

    The purpose of this study was to compare the systolic time intervals (STI) obtained by impedance cardiography and by the conventional carotid technique. This comparison was done with respect to: 1) correlations between variables obtained by the two methods, 2) ability to reflect drug-induced chan......The purpose of this study was to compare the systolic time intervals (STI) obtained by impedance cardiography and by the conventional carotid technique. This comparison was done with respect to: 1) correlations between variables obtained by the two methods, 2) ability to reflect drug...

  17. Electrostatic accelerators

    CERN Document Server

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We sketch possible applications and the progress in the development of electrostatic accelerators.

  18. Multipolar electrostatics.

    Science.gov (United States)

    Cardamone, Salvatore; Hughes, Timothy J; Popelier, Paul L A

    2014-06-14

    Atomistic simulation of chemical systems is currently limited by the elementary description of electrostatics that atomic point-charges offer. Unfortunately, a model of one point-charge for each atom fails to capture the anisotropic nature of electronic features such as lone pairs or π-systems. Higher order electrostatic terms, such as those offered by a multipole moment expansion, naturally recover these important electronic features. The question remains as to why such a description has not yet been widely adopted by popular molecular mechanics force fields. There are two widely-held misconceptions about the more rigorous formalism of multipolar electrostatics: (1) Accuracy: the implementation of multipole moments, compared to point-charges, offers little to no advantage in terms of an accurate representation of a system's energetics, structure and dynamics. (2) Efficiency: atomistic simulation using multipole moments is computationally prohibitive compared to simulation using point-charges. Whilst the second of these may have found some basis when computational power was a limiting factor, the first has no theoretical grounding. In the current work, we disprove the two statements above and systematically demonstrate that multipole moments are not discredited by either. We hope that this perspective will help in catalysing the transition to more realistic electrostatic modelling, to be adopted by popular molecular simulation software.

  19. Optimizing Time Intervals of Meteorological Data Used with Atmospheric Dose Modeling at SRS

    International Nuclear Information System (INIS)

    Simpkins, A.A.

    1999-01-01

    Measured tritium oxide concentrations in air have been compared with calculated values using routine release Gaussian plume models for different time intervals of meteorological data. These comparisons determined an optimum time interval of meteorological data used with atmospheric dose models at the Savannah River Site (SRS). Meteorological data of varying time intervals (1-yr to 10-yr) were used for the comparison. Insignificant differences are seen in using a one-year database as opposed to a five-year database. Use of a ten-year database results in slightly more conservative results. For meteorological databases of length one to five years the mean ratio of predicted to measured tritium oxide concentrations is approximately 1.25 whereas for the ten-year meteorological database the ration is closer to 1.35. Currently at the Savannah River Site a meteorological database of five years duration is used for all dose models. This study suggests no substantially improved accuracy using meteorological files of shorter or longer time intervals

  20. Count-to-count time interval distribution analysis in a fast reactor

    International Nuclear Information System (INIS)

    Perez-Navarro Gomez, A.

    1973-01-01

    The most important kinetic parameters have been measured at the zero power fast reactor CORAL-I by means of the reactor noise analysis in the time domain, using measurements of the count-to-count time intervals. (Author) 69 refs

  1. Automatic, time-interval traffic counts for recreation area management planning

    Science.gov (United States)

    D. L. Erickson; C. J. Liu; H. K. Cordell

    1980-01-01

    Automatic, time-interval recorders were used to count directional vehicular traffic on a multiple entry/exit road network in the Red River Gorge Geological Area, Daniel Boone National Forest. Hourly counts of entering and exiting traffic differed according to recorder location, but an aggregated distribution showed a delayed peak in exiting traffic thought to be...

  2. Time interval between cover crop termination and planting influences corn seedling disease, plant growth, and yield

    Science.gov (United States)

    Experiments were established in controlled and field environment to evaluate the effect of time intervals between cereal rye cover crop termination and corn planting on corn seedling disease, corn growth, and grain yield in 2014 and 2015. Rye termination dates ranged from 25 days before planting (DB...

  3. Entrained rhythmic activities of neuronal ensembles as perceptual memory of time interval.

    Science.gov (United States)

    Sumbre, Germán; Muto, Akira; Baier, Herwig; Poo, Mu-ming

    2008-11-06

    The ability to process temporal information is fundamental to sensory perception, cognitive processing and motor behaviour of all living organisms, from amoebae to humans. Neural circuit mechanisms based on neuronal and synaptic properties have been shown to process temporal information over the range of tens of microseconds to hundreds of milliseconds. How neural circuits process temporal information in the range of seconds to minutes is much less understood. Studies of working memory in monkeys and rats have shown that neurons in the prefrontal cortex, the parietal cortex and the thalamus exhibit ramping activities that linearly correlate with the lapse of time until the end of a specific time interval of several seconds that the animal is trained to memorize. Many organisms can also memorize the time interval of rhythmic sensory stimuli in the timescale of seconds and can coordinate motor behaviour accordingly, for example, by keeping the rhythm after exposure to the beat of music. Here we report a form of rhythmic activity among specific neuronal ensembles in the zebrafish optic tectum, which retains the memory of the time interval (in the order of seconds) of repetitive sensory stimuli for a duration of up to approximately 20 s. After repetitive visual conditioning stimulation (CS) of zebrafish larvae, we observed rhythmic post-CS activities among specific tectal neuronal ensembles, with a regular interval that closely matched the CS. Visuomotor behaviour of the zebrafish larvae also showed regular post-CS repetitions at the entrained time interval that correlated with rhythmic neuronal ensemble activities in the tectum. Thus, rhythmic activities among specific neuronal ensembles may act as an adjustable 'metronome' for time intervals in the order of seconds, and serve as a mechanism for the short-term perceptual memory of rhythmic sensory experience.

  4. Electrostatic hazards

    CERN Document Server

    Luttgens, Günter; Luttgens, Gnter; Luttgens, G Nter

    1997-01-01

    In the US, UK and Europe there is in excess of one notifiable dust or electrostatic explosion every day of the year. This clearly makes the hazards associated with the handling of materials subject to either cause or react to electrostatic discharge of vital importance to anyone associated with their handling or industrial bulk use. This book provides a comprehensive guide to the dangers of static electricity and how to avoid them. It will prove invaluable to safety managers and professionals, as well as all personnel involved in the activities concerned, in the chemical, agricultural, pharmaceutical and petrochemical process industries. The book makes extended use of case studies to illustrate the principles being expounded, thereby making it far more open, accessible and attractive to the practitioner in industry than the highly theoretical texts which are also available. The authors have many years' experience in the area behind them, including the professional teaching of the content provided here. Günte...

  5. Electrostatic accelerators

    OpenAIRE

    Hinterberger, F

    2006-01-01

    The principle of electrostatic accelerators is presented. We consider Cockcroft– Walton, Van de Graaff and Tandem Van de Graaff accelerators. We resume high voltage generators such as cascade generators, Van de Graaff band generators, Pelletron generators, Laddertron generators and Dynamitron generators. The speci c features of accelerating tubes, ion optics and methods of voltage stabilization are described. We discuss the characteristic beam properties and the variety of possible beams. We ...

  6. Online evolution reconstruction from a single measurement record with random time intervals for quantum communication

    Science.gov (United States)

    Zhou, Hua; Su, Yang; Wang, Rong; Zhu, Yong; Shen, Huiping; Pu, Tao; Wu, Chuanxin; Zhao, Jiyong; Zhang, Baofu; Xu, Zhiyong

    2017-10-01

    Online reconstruction of a time-variant quantum state from the encoding/decoding results of quantum communication is addressed by developing a method of evolution reconstruction from a single measurement record with random time intervals. A time-variant two-dimensional state is reconstructed on the basis of recovering its expectation value functions of three nonorthogonal projectors from a random single measurement record, which is composed from the discarded qubits of the six-state protocol. The simulated results prove that our method is robust to typical metro quantum channels. Our work extends the Fourier-based method of evolution reconstruction from the version for a regular single measurement record with equal time intervals to a unified one, which can be applied to arbitrary single measurement records. The proposed protocol of evolution reconstruction runs concurrently with the one of quantum communication, which can facilitate the online quantum tomography.

  7. Beat-to-beat systolic time-interval measurement from heart sounds and ECG

    International Nuclear Information System (INIS)

    Paiva, R P; Carvalho, P; Couceiro, R; Henriques, J; Antunes, M; Quintal, I; Muehlsteff, J

    2012-01-01

    Systolic time intervals are highly correlated to fundamental cardiac functions. Several studies have shown that these measurements have significant diagnostic and prognostic value in heart failure condition and are adequate for long-term patient follow-up and disease management. In this paper, we investigate the feasibility of using heart sound (HS) to accurately measure the opening and closing moments of the aortic heart valve. These moments are crucial to define the main systolic timings of the heart cycle, i.e. pre-ejection period (PEP) and left ventricular ejection time (LVET). We introduce an algorithm for automatic extraction of PEP and LVET using HS and electrocardiogram. PEP is estimated with a Bayesian approach using the signal's instantaneous amplitude and patient-specific time intervals between atrio-ventricular valve closure and aortic valve opening. As for LVET, since the aortic valve closure corresponds to the start of the S2 HS component, we base LVET estimation on the detection of the S2 onset. A comparative assessment of the main systolic time intervals is performed using synchronous signal acquisitions of the current gold standard in cardiac time-interval measurement, i.e. echocardiography, and HS. The algorithms were evaluated on a healthy population, as well as on a group of subjects with different cardiovascular diseases (CVD). In the healthy group, from a set of 942 heartbeats, the proposed algorithm achieved 7.66 ± 5.92 ms absolute PEP estimation error. For LVET, the absolute estimation error was 11.39 ± 8.98 ms. For the CVD population, 404 beats were used, leading to 11.86 ± 8.30 and 17.51 ± 17.21 ms absolute PEP and LVET errors, respectively. The results achieved in this study suggest that HS can be used to accurately estimate LVET and PEP. (paper)

  8. Postprandial oxidative losses of dietary leucine depend on the time interval between consecutive meals

    NARCIS (Netherlands)

    Myszkowska-Ryciak, J.; Keller, J.S.; Bujko, J.; Stankiewicz-Ciupa, J.; Koopmanschap, R.E.; Schreurs, V.V.A.M.

    2015-01-01

    Postprandial oxidative losses of egg white-bound [1-13C]-leucine were studied as 13C recovery in the breath of rats in relation to different time intervals between two meals. Male Wistar rats (n = 48; 68.3 ±5.9 g) divided into 4 groups (n = 12) were fed two meals a day (9:00

  9. Procedure prediction from symbolic Electronic Health Records via time intervals analytics.

    Science.gov (United States)

    Moskovitch, Robert; Polubriaginof, Fernanda; Weiss, Aviram; Ryan, Patrick; Tatonetti, Nicholas

    2017-11-01

    Prediction of medical events, such as clinical procedures, is essential for preventing disease, understanding disease mechanism, and increasing patient quality of care. Although longitudinal clinical data from Electronic Health Records provides opportunities to develop predictive models, the use of these data faces significant challenges. Primarily, while the data are longitudinal and represent thousands of conceptual events having duration, they are also sparse, complicating the application of traditional analysis approaches. Furthermore, the framework presented here takes advantage of the events duration and gaps. International standards for electronic healthcare data represent data elements, such as procedures, conditions, and drug exposures, using eras, or time intervals. Such eras contain both an event and a duration and enable the application of time intervals mining - a relatively new subfield of data mining. In this study, we present Maitreya, a framework for time intervals analytics in longitudinal clinical data. Maitreya discovers frequent time intervals related patterns (TIRPs), which we use as prognostic markers for modelling clinical events. We introduce three novel TIRP metrics that are normalized versions of the horizontal-support, that represents the number of TIRP instances per patient. We evaluate Maitreya on 28 frequent and clinically important procedures, using the three novel TIRP representation metrics in comparison to no temporal representation and previous TIRPs metrics. We also evaluate the epsilon value that makes Allen's relations more flexible with several settings of 30, 60, 90 and 180days in comparison to the default zero. For twenty-two of these procedures, the use of temporal patterns as predictors was superior to non-temporal features, and the use of the vertically normalized horizontal support metric to represent TIRPs as features was most effective. The use of the epsilon value with thirty days was slightly better than the zero

  10. Cardiac Time Intervals Measured by Tissue Doppler Imaging M-mode

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Møgelvang, Rasmus; Schnohr, Peter

    2016-01-01

    function was evaluated in 1915 participants by using both conventional echocardiography and tissue Doppler imaging (TDI). The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT), and ejection time (ET), were obtained by TDI M-mode through the mitral......). Additionally, they displayed a significant dose-response relationship, between increasing severity of elevated blood pressure and increasing left ventricular mass index (P

  11. Discrete time interval measurement system: fundamentals, resolution and errors in the measurement of angular vibrations

    International Nuclear Information System (INIS)

    Gómez de León, F C; Meroño Pérez, P A

    2010-01-01

    The traditional method for measuring the velocity and the angular vibration in the shaft of rotating machines using incremental encoders is based on counting the pulses at given time intervals. This method is generically called the time interval measurement system (TIMS). A variant of this method that we have developed in this work consists of measuring the corresponding time of each pulse from the encoder and sampling the signal by means of an A/D converter as if it were an analog signal, that is to say, in discrete time. For this reason, we have denominated this method as the discrete time interval measurement system (DTIMS). This measurement system provides a substantial improvement in the precision and frequency resolution compared with the traditional method of counting pulses. In addition, this method permits modification of the width of some pulses in order to obtain a mark-phase on every lap. This paper explains the theoretical fundamentals of the DTIMS and its application for measuring the angular vibrations of rotating machines. It also displays the required relationship between the sampling rate of the signal, the number of pulses of the encoder and the rotating velocity in order to obtain the required resolution and to delimit the methodological errors in the measurement

  12. [Estimation of the atrioventricular time interval by pulse Doppler in the normal fetal heart].

    Science.gov (United States)

    Hamela-Olkowska, Anita; Dangel, Joanna

    2009-08-01

    To assess normative values of the fetal atrioventricular (AV) time interval by pulse-wave Doppler methods on 5-chamber view. Fetal echocardiography exams were performed using Acuson Sequoia 512 in 140 singleton fetuses at 18 to 40 weeks of gestation with sinus rhythm and normal cardiac and extracardiac anatomy. Pulsed Doppler derived AV intervals were measured from left ventricular inflow/outflow view using transabdominal convex 3.5-6 MHz probe. The values of AV time interval ranged from 100 to 150 ms (mean 123 +/- 11.2). The AV interval was negatively correlated with the heart rhythm (page of gestation (p=0.007). However, in the same subgroup of the fetal heart rate there was no relation between AV intervals and gestational age. Therefore, the AV intervals showed only the heart rate dependence. The 95th percentiles of AV intervals according to FHR ranged from 135 to 148 ms. 1. The AV interval duration was negatively correlated with the heart rhythm. 2. Measurement of AV time interval is easy to perform and has a good reproducibility. It may be used for the fetal heart block screening in anti-Ro and anti-La positive pregnancies. 3. Normative values established in the study may help obstetricians in assessing fetal abnormalities of the AV conduction.

  13. Method to measure autonomic control of cardiac function using time interval parameters from impedance cardiography

    International Nuclear Information System (INIS)

    Meijer, Jan H; Boesveldt, Sanne; Elbertse, Eskeline; Berendse, H W

    2008-01-01

    The time difference between the electrocardiogram and impedance cardiogram can be considered as a measure for the time delay between the electrical and mechanical activities of the heart. This time interval, characterized by the pre-ejection period (PEP), is related to the sympathetic autonomous nervous control of cardiac activity. PEP, however, is difficult to measure in practice. Therefore, a novel parameter, the initial systolic time interval (ISTI), is introduced to provide a more practical measure. The use of ISTI instead of PEP was evaluated in three groups: young healthy subjects, patients with Parkinson's disease, and a group of elderly, healthy subjects of comparable age. PEP and ISTI were studied under two conditions: at rest and after an exercise stimulus. Under both conditions, PEP and ISTI behaved largely similarly in the three groups and were significantly correlated. It is concluded that ISTI can be used as a substitute for PEP and, therefore, to evaluate autonomic neuropathy both in clinical and extramural settings. Measurement of ISTI can also be used to non-invasively monitor the electromechanical cardiac time interval, and the associated autonomic activity, under physiological circumstances

  14. Comparison of equilibrium radionuclide and contrast angiographic measurements of left ventricular peak ejection and filling rates and their time intervals

    Energy Technology Data Exchange (ETDEWEB)

    Sugrue, D.D.; Dickie, S.; Newman, H.; Myers, M.J.; Lavender, J.P.; McKenna, W.J. (Royal Postgraduate Medical School, London (UK))

    1984-10-01

    A comparison has been made of the equilibrium radionuclide and contrast angiographic estimates of normalized peak rates of ejection (PER) and filling (PFR) and their time intervals in twenty-one patients with cardiac disorders. Contrast angiographic and radionuclide measurements of left ventricular ejection fraction (LVEF), PER and PFR correlated well but time intervals correlated poorly. Mean values for radionuclide LVEF, PER and PFR were significantly lower and radionuclide time intervals were significantly longer compared to contrast angiography measurements.

  15. Effect of a data buffer on the recorded distribution of time intervals for random events

    Energy Technology Data Exchange (ETDEWEB)

    Barton, J C [Polytechnic of North London (UK)

    1976-03-15

    The use of a data buffer enables the distribution of the time intervals between events to be studied for times less than the recording system dead-time but the usual negative exponential distribution for random events has to be modified. The theory for this effect is developed for an n-stage buffer followed by an asynchronous recorder. Results are evaluated for the values of n from 1 to 5. In the language of queueing theory the system studied is of type M/D/1/n+1, i.e. with constant service time and a finite number of places.

  16. The 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting

    International Nuclear Information System (INIS)

    Sydnor, R.L.

    1990-05-01

    Papers presented at the 22nd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting are compiled. The following subject areas are covered: Rb, Cs, and H-based frequency standards and cryogenic and trapped-ion technology; satellite laser tracking networks, GLONASS timing, intercomparison of national time scales and international telecommunications; telecommunications, power distribution, platform positioning, and geophysical survey industries; military communications and navigation systems; and dissemination of precise time and frequency by means of GPS, GLONASS, MIL STAR, LORAN, and synchronous communication satellites

  17. Detection of abnormal item based on time intervals for recommender systems.

    Science.gov (United States)

    Gao, Min; Yuan, Quan; Ling, Bin; Xiong, Qingyu

    2014-01-01

    With the rapid development of e-business, personalized recommendation has become core competence for enterprises to gain profits and improve customer satisfaction. Although collaborative filtering is the most successful approach for building a recommender system, it suffers from "shilling" attacks. In recent years, the research on shilling attacks has been greatly improved. However, the approaches suffer from serious problem in attack model dependency and high computational cost. To solve the problem, an approach for the detection of abnormal item is proposed in this paper. In the paper, two common features of all attack models are analyzed at first. A revised bottom-up discretized approach is then proposed based on time intervals and the features for the detection. The distributions of ratings in different time intervals are compared to detect anomaly based on the calculation of chi square distribution (χ(2)). We evaluated our approach on four types of items which are defined according to the life cycles of these items. The experimental results show that the proposed approach achieves a high detection rate with low computational cost when the number of attack profiles is more than 15. It improves the efficiency in shilling attacks detection by narrowing down the suspicious users.

  18. Detection of Abnormal Item Based on Time Intervals for Recommender Systems

    Directory of Open Access Journals (Sweden)

    Min Gao

    2014-01-01

    Full Text Available With the rapid development of e-business, personalized recommendation has become core competence for enterprises to gain profits and improve customer satisfaction. Although collaborative filtering is the most successful approach for building a recommender system, it suffers from “shilling” attacks. In recent years, the research on shilling attacks has been greatly improved. However, the approaches suffer from serious problem in attack model dependency and high computational cost. To solve the problem, an approach for the detection of abnormal item is proposed in this paper. In the paper, two common features of all attack models are analyzed at first. A revised bottom-up discretized approach is then proposed based on time intervals and the features for the detection. The distributions of ratings in different time intervals are compared to detect anomaly based on the calculation of chi square distribution (χ2. We evaluated our approach on four types of items which are defined according to the life cycles of these items. The experimental results show that the proposed approach achieves a high detection rate with low computational cost when the number of attack profiles is more than 15. It improves the efficiency in shilling attacks detection by narrowing down the suspicious users.

  19. Assessing cardiac preload by the Initial Systolic Time Interval obtained from impedance cardiography

    Directory of Open Access Journals (Sweden)

    Jan H Meijer

    2010-01-01

    Full Text Available The Initial Systolic Time Interval (ISTI, obtained from the electrocardiogram (ECG and impedance cardiogram (ICG, is considered to be a measure for the time delay between the electrical and mechanical activity of the heart and reflects an early active period of the cardiac cycle. The clinical relevance of this time interval is subject of study. This paper presents preliminary results of a pilot study investigating the use of ISTI in evaluating and predicting the circulatory response to fluid administration in patients after coronary artery bypass graft surgery, by comparing ISTI with cardiac output (CO responsiveness. Also the use of the pulse transit time (PTT, earlier recommended for this purpose, is investigated. The results show an inverse relationship between ISTI and CO at all moments of fluid administration and also an inverse relationship between the changes ΔISTI and ΔCO before and after full fluid administration. No relationships between PTT and CO or ΔPTT and ΔCO were found. It is concluded that ISTI is dependent upon preload, and that ISTI has the potential to be used as a clinical parameter assessing preload.

  20. Diagnostic Efficiency of MR Imaging of the Knee. Relationship to time Interval between MR and Arthroscopy

    International Nuclear Information System (INIS)

    Barrera, M. C.; Recondo, J. A.; Aperribay, M.; Gervas, C.; Fernandez, E.; Alustiza, J. M.

    2003-01-01

    To evaluate the efficiency of magnetic resonance (MR) in the diagnosis of knee lesions and how the results are influenced by the time interval between MR and arthroscopy. 248 knees studied by MR were retrospectively analyzed, as well as those which also underwent arthroscopy. Arthroscopy was considered to be the gold standard, MR diagnostic capacity was evaluated for both meniscal and cruciate ligament lesions. Sensitivity, specificity and Kappa index were calculated for the set of all knees included in the study (248), for those in which the time between MR and arthroscopy was less than or equal to three months (134) and for those in which the time between both procedures was less than or equal to one month. Sensitivity, specificity and Kappa index of the MR had global values of 96.5%, 70% and 71%, respectively. When the interval between MR and arthroscopy was less than or equal to three months, sensitivity, specificity and Kappa index were 95.5%, 75% and 72%, respectively. When it was less than or equal to one month, sensitivity was 100%, specificity was 87.5% and Kappa index was 91%. MR is an excellent tool for the diagnosis of knee lesions. Higher MR values of sensitivity, specificity and Kappa index are obtained when the time interval between both procedures is kept to a minimum. (Author) 11 refs

  1. Model for the respiratory modulation of the heart beat-to-beat time interval series

    Science.gov (United States)

    Capurro, Alberto; Diambra, Luis; Malta, C. P.

    2005-09-01

    In this study we present a model for the respiratory modulation of the heart beat-to-beat interval series. The model consists of a set of differential equations used to simulate the membrane potential of a single rabbit sinoatrial node cell, excited with a periodic input signal with added correlated noise. This signal, which simulates the input from the autonomous nervous system to the sinoatrial node, was included in the pacemaker equations as a modulation of the iNaK current pump and the potassium current iK. We focus at modeling the heart beat-to-beat time interval series from normal subjects during meditation of the Kundalini Yoga and Chi techniques. The analysis of the experimental data indicates that while the embedding of pre-meditation and control cases have a roughly circular shape, it acquires a polygonal shape during meditation, triangular for the Kundalini Yoga data and quadrangular in the case of Chi data. The model was used to assess the waveshape of the respiratory signals needed to reproduce the trajectory of the experimental data in the phase space. The embedding of the Chi data could be reproduced using a periodic signal obtained by smoothing a square wave. In the case of Kundalini Yoga data, the embedding was reproduced with a periodic signal obtained by smoothing a triangular wave having a rising branch of longer duration than the decreasing branch. Our study provides an estimation of the respiratory signal using only the heart beat-to-beat time interval series.

  2. Comparative evaluation of nickel discharge from brackets in artificial saliva at different time intervals.

    Science.gov (United States)

    Jithesh, C; Venkataramana, V; Penumatsa, Narendravarma; Reddy, S N; Poornima, K Y; Rajasigamani, K

    2015-08-01

    To determine and compare the potential difference of nickel release from three different orthodontic brackets, in different artificial pH, in different time intervals. Twenty-seven samples of three different orthodontic brackets were selected and grouped as 1, 2, and 3. Each group was divided into three subgroups depending on the type of orthodontic brackets, salivary pH and the time interval. The Nickel release from each subgroup were analyzed by using inductively coupled plasma-Atomic Emission Spectrophotometer (Perkin Elmer, Optima 2100 DV, USA) model. Quantitative analysis of nickel was performed three times, and the mean value was used as result. ANOVA (F-test) was used to test the significant difference among the groups at 0.05 level of significance (P brackets have the highest at all 4.2 pH except in 120 h. The study result shows that the nickel release from the recycled stainless steel brackets is highest. Metal slot ceramic bracket release significantly less nickel. So, recycled stainless steel brackets should not be used for nickel allergic patients. Metal slot ceramic brackets are advisable.

  3. Time interval between stroke onset and hospital arrival in acute ischemic stroke patients in Shanghai, China.

    Science.gov (United States)

    Fang, Jing; Yan, Weihong; Jiang, Guo-Xin; Li, Wei; Cheng, Qi

    2011-02-01

    To observe the time interval between stroke onset and hospital arrival (time-to-hospital) in acute ischemic stroke patients and analyze its putatively associated factors. During the period from November 1, 2006 to August 31, 2008, patients with acute ischemic stroke admitted consecutively to the Department of Neurology, Ninth Hospital, Shanghai, were enrolled in the study. Information of the patients was registered including the time-to-hospital, demographic data, history of stroke, season at attack, neurological symptom at onset, etc. Characteristics of the patients were analyzed and logistic regression analyses were conducted to identify factors associated with the time-to-hospital. There were 536 patients in the study, 290 (54.1%) males and 246 (45.9%) females. The median time-to-hospital was 8h (ranged from 0.1 to 300 h) for all patients. Within 3h after the onset of stroke, 162 patients (30.2%) arrived at our hospital; and within 6h, 278 patients (51.9%). Patients with a history of stroke, unconsciousness at onset, or a high NIHSS score at admission had significantly less time-to-hospital. The time interval between stroke onset and hospital arrival was importance of seeking immediate medical help after stroke onset of patients and their relatives could significantly influence their actions. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Effects of varied doses of psilocybin on time interval reproduction in human subjects.

    Science.gov (United States)

    Wackermann, Jirí; Wittmann, Marc; Hasler, Felix; Vollenweider, Franz X

    2008-04-11

    Action of a hallucinogenic substance, psilocybin, on internal time representation was investigated in two double-blind, placebo-controlled studies: Experiment 1 with 12 subjects and graded doses, and Experiment 2 with 9 subjects and a very low dose. The task consisted in repeated reproductions of time intervals in the range from 1.5 to 5s. The effects were assessed by parameter kappa of the 'dual klepsydra' model of internal time representation, fitted to individual response data and intra-individually normalized with respect to initial values. The estimates kappa were in the same order of magnitude as in earlier studies. In both experiments, kappa was significantly increased by psilocybin at 90 min from the drug intake, indicating a higher loss rate of the internal duration representation. These findings are tentatively linked to qualitative alterations of subjective time in altered states of consciousness.

  5. Optimal time interval between capecitabine intake and radiotherapy in preoperative chemoradiation for locally advanced rectal cancer

    International Nuclear Information System (INIS)

    Yu, Chang Sik; Kim, Tae Won; Kim, Jong Hoon; Choi, Won Sik; Kim, Hee Cheol; Chang, Heung Moon; Ryu, Min Hee; Jang, Se Jin; Ahn, Seung Do; Lee, Sang-wook; Shin, Seong Soo; Choi, Eun Kyung; Kim, Jin Cheon

    2007-01-01

    Purpose: Capecitabine and its metabolites reach peak plasma concentrations 1 to 2 hours after a single oral administration, and concentrations rapidly decrease thereafter. We performed a retrospective analysis to find the optimal time interval between capecitabine administration and radiotherapy for rectal cancer. Methods and Materials: The time interval between capecitabine intake and radiotherapy was measured in patients who were treated with preoperative radiotherapy and concurrent capecitabine for rectal cancer. Patients were classified into the following groups. Group A1 included patients who took capecitabine 1 hour before radiotherapy, and Group B1 included all other patients. Group B1 was then subdivided into Group A2 (patients who took capecitabine 2 hours before radiotherapy) and Group B2. Group B2 was further divided into Group A3 and Group B3 with the same method. Total mesorectal excision was performed 6 weeks after completion of chemoradiation and the pathologic response was evaluated. Results: A total of 200 patients were enrolled in this study. Pathologic examination showed that Group A1 had higher rates of complete regression of primary tumors in the rectum (23.5% vs. 9.6%, p = 0.01), good response (44.7% vs. 25.2%, p = 0.006), and lower T stages (p = 0.021) compared with Group B1; however, Groups A2 and A3 did not show any improvement compared with Groups B2 and B3. Multivariate analysis showed that increases in primary tumors in the rectum and good response were only significant when capecitabine was administered 1 hour before radiotherapy. Conclusion: In preoperative chemoradiotherapy for rectal cancer, the pathologic response could be improved by administering capecitabine 1 hour before radiotherapy

  6. Dimensional Stability of Two Polyvinyl Siloxane Impression Materials in Different Time Intervals

    Directory of Open Access Journals (Sweden)

    Aalaei Sh

    2015-12-01

    Full Text Available Statement of the Problem: Dental prosthesis is usually made indirectly; there- fore dimensional stability of the impression material is very important. Every few years, new impression materials with different manufacturers’ claims regarding their better properties are introduced to the dental markets which require more research to evaluate their true dimensional changes. Objectives: The aim of this study was to evaluate dimensional stability of additional silicone impression material (Panasil® and Affinis® in different time intervals. Materials and Methods: In this experimental study, using two additional silicones (Panasil® and Affinis®, we made sixty impressions of standard die in similar conditions of 23 °C and 59% relative humidity by a special tray. The die included three horizontal and two vertical lines that were parallel. The vertical line crossed the horizontal ones at a point that served as reference for measurement. All impressions were poured with high strength dental stone. The dimensions were measured by stereo-microscope by two examiners in three interval storage times (1, 24 and 168 hours.The data were statistically analyzed using t-test and ANOVA. Results: All of the stone casts were larger than the standard die. Dimensional changes of Panasil and Affinis were 0.07%, 0.24%, 0.27% and 0.02%, 0.07%, 0.16% after 1, 24 and 168 hours, respectively. Dimensional change for two impression materials wasn’t significant in the interval time, expect for Panasil after one week (p = 0.004. Conclusions: According to the limitations of this study, Affinis impressions were dimensionally more stable than Panasil ones, but it was not significant. Dimensional change of Panasil impression showed a statistically significant difference after one week. Dimensional changes of both impression materials were based on ADA standard limitation in all time intervals (< 0.5%; therefore, dimensional stability of this impression was accepted at least

  7. Assessment of time interval between tramadol intake and seizure and second drug-induced attack

    Directory of Open Access Journals (Sweden)

    Bahareh Abbasi

    2015-11-01

    Full Text Available Background: Tramadol is a synthetic drug which is prescribed in moderate and severe pain. Tramadol overdose can induce severe complications such as consciousness impairment and convulsions. This study was done to determine the convulsions incidence after tramadol use until one week after hospital discharge. Methods: This prospective study was done in tramadol overdose patients without uncontrolled epilepsy and head injury history. All cases admitted in Loghman and Rasol Akram Hospitals, Tehran, Iran from 1, April 2011 to 1, April 2012 were included and observed for at least 12 hours. Time interval between tramadol intake and first seizure were record. Then, patients with second drug-induced seizure were recognized and log time between the first and second seizure was analyzed. The patients were transferred to the intensive care unit (ICU if clinical worsening status observed. One week after hospital discharge, telephone follow-up was conducted. Results: A total of 150 patients with a history of tramadol induced seizures (141 men, 9 women, age: 23.23±5.94 years were enrolled in this study. Convulsion was seen in 104 patients (69.3%. In 8 out of 104 patients (7.6% two or more convulsion was seen. Time interval between tramadol use and the onset of the first and second seizure were 0.93±0.17 and 2.5±0.75 hours, respectively. Tramadol induced seizures are more likely to occur in males and patients with a history of drug abuse. Finally, one hundred forty nine patients (99.3% were discharged with good condition and the only one patient died from tramadol overdose. Conclusion: The results of the study showed tramadol induced seizure most frequently occurred within the first 4 hours of tramadol intake. The chance of experiencing a second seizure exists in the susceptible population. Thus, 4 hours after drug intake is the best time for patients to be hospital discharged.

  8. Rapid determination of long-lived artificial alpha radionuclides using time interval analysis

    International Nuclear Information System (INIS)

    Uezu, Yasuhiro; Koarashi, Jun; Sanada, Yukihisa; Hashimoto, Tetsuo

    2003-01-01

    It is important to monitor long lived alpha radionuclides as plutonium ( 238 Pu, 239+240 Pu) in the field of working area and environment of nuclear fuel cycle facilities, because it is well known that potential risks of cancer-causing from alpha radiation is higher than gamma radiations. Thus, these monitoring are required high sensitivity, high resolution and rapid determination in order to measure a very low-level concentration of plutonium isotopes. In such high sensitive monitoring, natural radionuclides, including radon ( 222 Rn or 220 Rn) and their progenies, should be eliminated as low as possible. In this situation, a sophisticated discrimination method between Pu and progenies of 222 Rn or 220 Rn using time interval analysis (TIA), which was able to subtract short-lived radionuclides using the time interval distributions calculation of successive alpha and beta decay events within millisecond or microsecond orders, was designed and developed. In this system, alpha rays from 214 Po, 216 Po and 212 Po are extractable. TIA measuring system composes of Silicon Surface Barrier Detector (SSD), an amplifier, an Analog to Digital Converter (ADC), a Multi-Channel Analyzer (MCA), a high-resolution timer (TIMER), a multi-parameter collector and a personal computer. In ADC, incidental alpha and beta pulses are sent to the MCA and the TIMER simultaneously. Pulses from them are synthesized by the multi-parameter collector. After measurement, natural radionuclides are subtracted. Airborne particles were collected on membrane filter for 60 minutes at 100 L/min. Small Pu particles were added on the surface of it. Alpha and beta rays were measured and natural radionuclides were subtracted within 5 times of 145 msec. by TIA. As a result of it, the hidden Pu in natural background could be recognized clearly. The lower limit of determination of 239 Pu is calculated as 6x10 -9 Bq/cm 3 . This level is satisfied with the derived air concentration (DAC) of 239 Pu (8x10 -9 Bq/cm 3

  9. Conversion rate of laparoscopic cholecystectomy after endoscopic retrograde cholangiography in the treatment of choledocholithiasis - Does the time interval matter?

    NARCIS (Netherlands)

    de Vries, A.; Donkervoort, S. C.; van Geloven, A. A. W.; Pierik, E. G. J. M.

    2005-01-01

    Background: Preceding endoscopic retrograde cholangiography (ERC) in patients with choledochocystolithiasis impedes laparoscopic cholecystectomy (LC) and increases risk of conversion. We studied the influence of time interval between ERC and LC on the course of LC. Methods: All patients treated for

  10. Cardiac time intervals and the association with 2D-speckle-tracking, tissue Doppler and conventional echocardiography

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Jensen, Jan Skov; Andersen, Henrik Ullits

    2016-01-01

    Cardiac time intervals (CTI) are prognostic above and beyond conventional echocardiographic measures. The explanation may be that CTI contain information about both systolic and diastolic measures; this is, however, unknown. The relationship between the CTI and systolic and diastolic function...

  11. Simultaneous determination of radionuclides separable into natural decay series by use of time-interval analysis

    International Nuclear Information System (INIS)

    Hashimoto, Tetsuo; Sanada, Yukihisa; Uezu, Yasuhiro

    2004-01-01

    A delayed coincidence method, time-interval analysis (TIA), has been applied to successive α-α decay events on the millisecond time-scale. Such decay events are part of the 220 Rn→ 216 Po (T 1/2 145 ms) (Th-series) and 219 Rn→ 215 Po (T 1/2 1.78 ms) (Ac-series). By using TIA in addition to measurement of 226 Ra (U-series) from α-spectrometry by liquid scintillation counting (LSC), two natural decay series could be identified and separated. The TIA detection efficiency was improved by using the pulse-shape discrimination technique (PSD) to reject β-pulses, by solvent extraction of Ra combined with simple chemical separation, and by purging the scintillation solution with dry N 2 gas. The U- and Th-series together with the Ac-series were determined, respectively, from alpha spectra and TIA carried out immediately after Ra-extraction. Using the 221 Fr→ 217 At (T 1/2 32.3 ms) decay process as a tracer, overall yields were estimated from application of TIA to the 225 Ra (Np-decay series) at the time of maximum growth. The present method has proven useful for simultaneous determination of three radioactive decay series in environmental samples. (orig.)

  12. Using the Initial Systolic Time Interval to assess cardiac autonomic function in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Jan H. Meijer

    2011-12-01

    Full Text Available The Initial Systolic Time Interval (ISTI has been defined as the time difference between the peak electrical and peak mechanical activity of the heart. ISTI is obtained from the electro-cardiogram and the impedance cardiogram. The response of ISTI while breathing at rest and to a deep breathing stimulus was studied in a group of patients suffering from Parkinson's disease (PD and a group of healthy control subjects. ISTI showed substantial variability during these manoeuvres. The tests showed that the variability of RR and ISTI was substantially different between PD patients and controls. It is hypothesized that in PD patients the sympathetic system compensates for the loss of regulatory control function of the blood-pressure by the parasympathetic system. It is concluded that ISTI is a practical, additional and independent parameter that can be used to assist other tests in evaluating autonomic control of the heart in PD patients.doi:10.5617/jeb.216 J Electr Bioimp, vol. 2, pp. 98-101, 2011

  13. Brain response during the M170 time interval is sensitive to socially relevant information.

    Science.gov (United States)

    Arviv, Oshrit; Goldstein, Abraham; Weeting, Janine C; Becker, Eni S; Lange, Wolf-Gero; Gilboa-Schechtman, Eva

    2015-11-01

    Deciphering the social meaning of facial displays is a highly complex neurological process. The M170, an event related field component of MEG recording, like its EEG counterpart N170, was repeatedly shown to be associated with structural encoding of faces. However, the scope of information encoded during the M170 time window is still being debated. We investigated the neuronal origin of facial processing of integrated social rank cues (SRCs) and emotional facial expressions (EFEs) during the M170 time interval. Participants viewed integrated facial displays of emotion (happy, angry, neutral) and SRCs (indicated by upward, downward, or straight head tilts). We found that the activity during the M170 time window is sensitive to both EFEs and SRCs. Specifically, highly prominent activation was observed in response to SRC connoting dominance as compared to submissive or egalitarian head cues. Interestingly, the processing of EFEs and SRCs appeared to rely on different circuitry. Our findings suggest that vertical head tilts are processed not only for their sheer structural variance, but as social information. Exploring the temporal unfolding and brain localization of non-verbal cues processing may assist in understanding the functioning of the social rank biobehavioral system. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. CMOS direct time interval measurement of long-lived luminescence lifetimes.

    Science.gov (United States)

    Yao, Lei; Yung, Ka Yi; Cheung, Maurice C; Chodavarapu, Vamsy P; Bright, Frank V

    2011-01-01

    We describe a Complementary Metal-Oxide Semiconductor (CMOS) Direct Time Interval Measurement (DTIM) Integrated Circuit (IC) to detect the decay (fall) time of the luminescence emission when analyte-sensitive luminophores are excited with an optical pulse. The CMOS DTIM IC includes 14 × 14 phototransistor array, transimpedance amplifier, regulated gain amplifier, fall time detector, and time-to-digital convertor. We examined the DTIM system to measure the emission lifetime of oxygen-sensitive luminophores tris(4,7-diphenyl-1, 10-phenanthroline) ruthenium(II) ([Ru(dpp)(3)](2+)) encapsulated in sol-gel derived xerogel thin-films. The DTIM system fabricated using TSMC 0.35 μm process functions to detect lifetimes from 4 μs to 14.4 μs but can be tuned to detect longer lifetimes. The system provides 8-bit digital output proportional to lifetimes and consumes 4.5 mW of power with 3.3 V DC supply. The CMOS system provides a useful platform for the development of reliable, robust, and miniaturized optical chemical sensors.

  15. Hybrid neuro-heuristic methodology for simulation and control of dynamic systems over time interval.

    Science.gov (United States)

    Woźniak, Marcin; Połap, Dawid

    2017-09-01

    Simulation and positioning are very important aspects of computer aided engineering. To process these two, we can apply traditional methods or intelligent techniques. The difference between them is in the way they process information. In the first case, to simulate an object in a particular state of action, we need to perform an entire process to read values of parameters. It is not very convenient for objects for which simulation takes a long time, i.e. when mathematical calculations are complicated. In the second case, an intelligent solution can efficiently help on devoted way of simulation, which enables us to simulate the object only in a situation that is necessary for a development process. We would like to present research results on developed intelligent simulation and control model of electric drive engine vehicle. For a dedicated simulation method based on intelligent computation, where evolutionary strategy is simulating the states of the dynamic model, an intelligent system based on devoted neural network is introduced to control co-working modules while motion is in time interval. Presented experimental results show implemented solution in situation when a vehicle transports things over area with many obstacles, what provokes sudden changes in stability that may lead to destruction of load. Therefore, applied neural network controller prevents the load from destruction by positioning characteristics like pressure, acceleration, and stiffness voltage to absorb the adverse changes of the ground. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Measurement of the ecological flow of the Acaponeta river, Nayarit, comparing different time intervals

    Directory of Open Access Journals (Sweden)

    Guadalupe de la Lanza Espino

    2012-07-01

    Full Text Available The diverse management of river water in Mexico has been unequal due to the different anthropological activities, and it is associated with inter-annual changes in the climate and runoff patterns, leading to a loss of the ecosystem integrity. However, nowadays there are different methods to assess the water volume that is necessary to conserve the environment, among which are hydrological methods, such as those applied here, that are based on information on water volumes recorded over decades, which are not always available in the country. For this reason, this study compares runoff records for different time ranges: minimum of 10 years, medium of 20 years, and more than 50 years, to quantify the environmental flow. These time intervals provided similar results, which mean that not only for the Acaponeta river, but possibly for others lotic systems as well, a 10-year interval may be used satisfactorily. In this river, the runoff water that must be kept for environmental purposes is: for 10 years 70.1%, for 20 years 78.1% and for >50 years 68.8%, with an average of 72.3% of the total water volume or of the average annual runoff.

  17. Heat Generation on Implant Surface During Abutment Preparation at Different Elapsed Time Intervals.

    Science.gov (United States)

    Al-Keraidis, Abdullah; Aleisa, Khalil; Al-Dwairi, Ziad Nawaf; Al-Tahawi, Hamdi; Hsu, Ming-Lun; Lynch, Edward; Özcan, Mutlu

    2017-10-01

    The purpose of this study was to evaluate heat generation at the implant surface caused by abutment preparation using a diamond bur in a high-speed dental turbine in vitro at 2 different water-coolant temperatures. Thirty-two titanium-alloy abutments were connected to a titanium-alloy implant embedded in an acrylic resin placed within a water bath at a controlled temperature of 37°C. The specimens were equally distributed into 2 groups (16 each). Group 1: the temperature was maintained at 20 ± 1°C; and group 2: the temperature was maintained at 32 ± 1°C. Each abutment was prepared in the axial plane for 1 minute and in the occlusal plane for 1 minute. The temperature of the heat generated from abutment preparation was recorded and measured at 3 distinct time intervals. Water-coolant temperature (20°C vs 32°C) had a statistically significant effect on the implant's temperature change during preparation of the abutment (P water-coolant temperature of 20 ± 1°C during preparation of the implant abutment decreased the temperature recorded at the implant surface to 34.46°C, whereas the coolant temperature of 32 ± 1°C increased the implant surface temperature to 40.94°C.

  18. The Perforation-Operation time Interval; An Important Mortality Indicator in Peptic Ulcer Perforation.

    Science.gov (United States)

    Surapaneni, Sushama; S, Rajkumar; Reddy A, Vijaya Bhaskar

    2013-05-01

    To find out the significance of the Perforation-Operation Interval (POI) with respect to an early prognosis, in patients with peritonitis which is caused by peptic ulcer perforation. Case series. Place and Duration of the Study: Department of General Surgery, Konaseema Institute of Medical Sciences and RF Amalapuram, Andhra Pradesh, India from 2008-2011. This study included 150 patients with generalized peritonitis, who were diagnosed to have Perforated Peptic Ulcers (PPUs). The diagnosis of the PPUs was established on the basis of the history , the clinical examination and the radiological findings. The perforation-operation interval was calculated from the time of onset of the symptoms like severe abdominal pain or vomiting till the time the patient was operated. Out of the 150 patients 134 were males and 16 were females, with a male : female ratio of 9:1. Their ages ranged between 25-70 years. Out of the 150 patients, 65 patients (43.3%) presented within 24 hours of the onset of severe abdominal pain (Group A), 27 patients (18%) presented between 24-48 hours of the onset of severe abdominal pain (Group B) and 58 patients (38.6%) presented after 48 hours. There was no mortality in Group A and the morbidity was more in Group B and Group C. There were 15 deaths in Group C. The problem of peptic ulcer perforation with its complication, can be decreased by decreasing the perforation -operation time interval, which as per our study, appeared to be the single most important mortality and morbidity indicator in peptic ulcer perforation.

  19. Lethal pedestrian--passenger car collisions in Berlin. Changed injury patterns in two different time intervals.

    Science.gov (United States)

    Ehrlich, Edwin; Tischer, Anja; Maxeiner, H

    2009-04-01

    To expand the passive safety of automobiles protecting traffic participants technological innovations were done in the last decades. Objective of our retrospective analysis was to examine if these technical modifications led to a clearly changed pattern of injuries of pedestrians whose death was caused by the accidents. Another reduction concerns the exclusion of injured car passengers--only pedestrians walking or standing at the moment of collision were included. We selected time intervals 1975-1985 and 1991-2004 (=years of construction of the involved passenger cars). The cars were classified depending on their frontal construction in types as presented by Schindler et al. [Schindler V, Kühn M, Weber S, Siegler H, Heinrich T. Verletzungsmechanismen und Wirkabschätzungen der Fahrzegfrontgestaltung bei Pkw-Fussgänger-Kollisionen. Abschlussbericht im Auftrag der Deutschen Versicherungswirtschaft e.V. TU-Berlin Fachgebiet Kraftfahrzeuge (GDV) 2004:36-40]. In both periods more than 90% of all cars were from the usual types small/medium/large class. Hundred and thirty-four autopsy records of such cases from Department of Forensic Medicine (Charité Berlin) data were analysed. The data included technical information of the accidents and vehicles and the external and internal injuries of the victims. The comparison of the two periods showed a decrease of serious head injuries and femoral fractures but an increase of chest-, abdominal and pelvic injuries. This situation could be explained by an increased occurrence of soft-face-constructions and changed front design of modern passenger cars, resulting in a favourable effects concerning head impact to the car during accident. Otherwise the same kinetic energy was transferred to the (complete) victim - but because of a displacement of main focus of impact the pattern of injuries modified (went distally).

  20. Initial Systolic Time Interval (ISTI) as a Predictor of Intradialytic Hypotension (IDH)

    International Nuclear Information System (INIS)

    Biesheuvel, J D; Verdaasdonk, R M; Meijer, JH; Vervloet, M G

    2013-01-01

    In haemodialysis treatment the clearance and volume control by the kidneys of a patient are partially replaced by intermittent haemodialysis. Because this artificial process is performed on a limited time scale, unphysiological imbalances in the fluid compartments of the body occur, that can lead to intradialytic hypotensions (IDH). An IDH endangers the efficacy of the haemodialysis session and is associated with dismal clinical endpoints, including mortality. A diagnostic method that predicts the occurrence of these drops in blood pressure could facilitate timely measures for the prevention of IDH. The present study investigates whether the Initial Systolic Time Interval (ISTI) can provide such a diagnostic method. The ISTI is defined as the time difference between the R-peak in the electrocardiogram (ECG) and the C-wave in the impedance cardiogram (ICG) and is considered to be a non-invasive assessment of the time delay between the electrical and mechanical activity of the heart. This time delay has previously been found to depend on autonomic nervous function as well as preload of the heart. Therefore, it can be expected that ISTI may predict an imminent IDH caused by a low circulating blood volume. This ongoing observational clinical study investigates the relationship between changes in ISTI and subsequent drops in blood pressure during haemodialysis. A registration of a complicated dialysis showed a significant correlation between a drop in blood pressure, a decrease in relative blood volume and a substantial increase in ISTI. An uncomplicated dialysis, in which also a considerable amount of fluid was removed, showed no correlations. Both, blood pressure and ISTI remained stable. In conclusion, the preliminary results of the present study show a substantial response of ISTI to haemodynamic instability, indicating an application in optimization and individualisation of the dialysis process.

  1. Association between prehospital time interval and short-term outcome in acute heart failure patients.

    Science.gov (United States)

    Takahashi, Masashi; Kohsaka, Shun; Miyata, Hiroaki; Yoshikawa, Tsutomu; Takagi, Atsutoshi; Harada, Kazumasa; Miyamoto, Takamichi; Sakai, Tetsuo; Nagao, Ken; Sato, Naoki; Takayama, Morimasa

    2011-09-01

    Acute heart failure (AHF) is one of the most frequently encountered cardiovascular conditions that can seriously affect the patient's prognosis. However, the importance of early triage and treatment initiation in the setting of AHF has not been recognized. The Tokyo Cardiac Care Unit Network Database prospectively collected information of emergency admissions to acute cardiac care facilities in 2005-2007 from 67 participating hospitals in the Tokyo metropolitan area. We analyzed records of 1,218 AHF patients transported to medical centers via emergency medical services (EMS). AHF was defined as rapid onset or change in the signs and symptoms of heart failure, resulting in the need for urgent therapy. Patients with acute coronary syndrome were excluded from this analysis. Logistic regression analysis was performed to calculate the risk-adjusted in-hospital mortality. A majority of the patients were elderly (76.1 ± 11.5 years old) and male (54.1%). The overall in-hospital mortality rate was 6.0%. The median time interval between symptom onset and EMS arrival (response time) was 64 minutes (interquartile range [IQR] 26-205 minutes), and that between EMS arrival and ER arrival (transportation time) was 27 minutes (IQR 9-78 minutes). The risk-adjusted mortality increased with transportation time, but did not correlate with the response time. Those who took >45 minutes to arrive at the medical centers were at a higher risk for in-hospital mortality (odds ratio 2.24, 95% confidence interval 1.17-4.31; P = .015). Transportation time correlated with risk-adjusted mortality, and steps should be taken to reduce the EMS transfer time to improve the outcome in AHF patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Evaluating Protocol Lifecycle Time Intervals in HIV/AIDS Clinical Trials

    Science.gov (United States)

    Schouten, Jeffrey T.; Dixon, Dennis; Varghese, Suresh; Cope, Marie T.; Marci, Joe; Kagan, Jonathan M.

    2014-01-01

    Background Identifying efficacious interventions for the prevention and treatment of human diseases depends on the efficient development and implementation of controlled clinical trials. Essential to reducing the time and burden of completing the clinical trial lifecycle is determining which aspects take the longest, delay other stages, and may lead to better resource utilization without diminishing scientific quality, safety, or the protection of human subjects. Purpose In this study we modeled time-to-event data to explore relationships between clinical trial protocol development and implementation times, as well as identify potential correlates of prolonged development and implementation. Methods We obtained time interval and participant accrual data from 111 interventional clinical trials initiated between 2006 and 2011 by NIH’s HIV/AIDS Clinical Trials Networks. We determined the time (in days) required to complete defined phases of clinical trial protocol development and implementation. Kaplan-Meier estimates were used to assess the rates at which protocols reached specified terminal events, stratified by study purpose (therapeutic, prevention) and phase group (pilot/phase I, phase II, and phase III/ IV). We also examined several potential correlates to prolonged development and implementation intervals. Results Even though phase grouping did not determine development or implementation times of either therapeutic or prevention studies, overall we observed wide variation in protocol development times. Moreover, we detected a trend toward phase III/IV therapeutic protocols exhibiting longer developmental (median 2 ½ years) and implementation times (>3years). We also found that protocols exceeding the median number of days for completing the development interval had significantly longer implementation. Limitations The use of a relatively small set of protocols may have limited our ability to detect differences across phase groupings. Some timing effects

  3. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 7. Electrostatics in Chemistry - Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 7 July 1999 pp 14-23 ...

  4. The Geomagnetic Field Recorded in Sediments of the Tuzla Section (the Krasnodar Territory, Russia) over the Time Interval 120-70 ka

    DEFF Research Database (Denmark)

    Pilipenko, Olga; Abrahamsen, N.; Trubikhin, V. M.

    2007-01-01

    Petro- and paleomagnetic methods are applied to the study of the lower part of the Early Pleistocene Tuzla section on the Black Sea coast of the Taman Peninsula. This part of the section is composed of marine and lagoonal sediments deposited over the time interval 120-70 ka. The measured curves...... of the variation in the geomagnetic field inclination reveal an anomalous direction dated at ~110 ka which coincides with a similar anomalous direction in the Eltigen section (Ukraine) correlating with the Blake paleomagnetic event. The significant correlation between the time series NRM0.015/SIRM0.015 (Tuzla...

  5. The time interval distribution of sand–dust storms in theory: testing with observational data for Yanchi, China

    International Nuclear Information System (INIS)

    Liu, Guoliang; Zhang, Feng; Hao, Lizhen

    2012-01-01

    We previously introduced a time record model for use in studying the duration of sand–dust storms. In the model, X is the normalized wind speed and Xr is the normalized wind speed threshold for the sand–dust storm. X is represented by a random signal with a normal Gaussian distribution. The storms occur when X ≥ Xr. From this model, the time interval distribution of N = Aexp(−bt) can be deduced, wherein N is the number of time intervals with length greater than t, A and b are constants, and b is related to Xr. In this study, sand–dust storm data recorded in spring at the Yanchi meteorological station in China were analysed to verify whether the time interval distribution of the sand–dust storms agrees with the above time interval distribution. We found that the distribution of the time interval between successive sand–dust storms in April agrees well with the above exponential equation. However, the interval distribution for the sand–dust storm data for the entire spring period displayed a better fit to the Weibull equation and depended on the variation of the sand–dust storm threshold wind speed. (paper)

  6. The electrostatic atomization of hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, A J

    1984-06-01

    Exploitation of the unique and potentially beneficial characteristics of electrostatic atomization in combustion systems has foundered upon the inability of two element, diode devices to operate at flow rates that are larger than a fraction of a millilitre per second. This restriction has been attributed to the high innate electrical resistivity of hydrocarbon fuels. A discussion of proposed electrostatic fuel atomizers and their limitations is presented from the vantage of a recently developed theory of electrostatic spraying. Comparison of theory and experiment reveals the existence of a 'constant of spraying' and the presence of an operational regime in which low charge density droplet development is possible. Operation with hydrocarbons in this regime occurs when the mean droplet size is greater than or equal to 10 ..mu..m and fluid viscosity is below about 250 cp. The resulting spray has a mean droplet size that is functionally dependent only upon the free charge density level of the fluid. Consequently there is no theoretical impediment to the attainment of high flow rate electrostatic atomization with fluids of arbitrary conductivity. Implementation is achieved by a general class of electrostatic spray devices which employ direct charge injection. The Spray Triode, a submerged field-emission electron gun, represents a particularly simple member of this new class of atomizer. Among the Spray Triode operational characteristics to be discussed is insensitivity to spray fluid properties and flow rate.

  7. Large electrostatic accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1984-01-01

    The paper is divided into four parts: a discussion of the motivation for the construction of large electrostatic accelerators, a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year

  8. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Electrostatics in Chemistry. 3. Molecular Electrostatic Potential: Visualization and Topography. Shridhar R Gadre and Pravin K Bhadane. 1 1. Basic Principles, Resona- nce, Vol.4, No.2, 11-19, 1999. 2. Electrostatic Potentials of. Atoms, Ions and Molecules,. Resonance, Vol.4, No.5, 40-51,. 1999. Topographical features of the ...

  9. Determination and identification of naturally occurring decay series using milli-second order pulse time interval analysis (TIA)

    International Nuclear Information System (INIS)

    Hashimoto, T.; Sanada, Y.; Uezu, Y.

    2003-01-01

    A delayed coincidence method, called a time interval analysis (TIA) method, has been successfully applied to selective determination of the correlated α-α decay events in millisecond order life-time. A main decay process applicable to TIA-treatment is 220 Rn → 216 Po(T 1/2 :145ms) → {Th-series}. The TIA is fundamentally based on the difference of time interval distribution between non-correlated decay events and other events such as background or random events when they were compiled the time interval data within a fixed time (for example, a tenth of concerned half lives). The sensitivity of the TIA-analysis due to correlated α-α decay events could be subsequently improved in respect of background elimination using the pulse shape discrimination technique (PSD with PERALS counter) to reject β/γ-pulses, purging of nitrogen gas into extra scintillator, and applying solvent extraction of Ra. (author)

  10. Compact electrostatic comb actuator

    Science.gov (United States)

    Rodgers, M. Steven; Burg, Michael S.; Jensen, Brian D.; Miller, Samuel L.; Barnes, Stephen M.

    2000-01-01

    A compact electrostatic comb actuator is disclosed for microelectromechanical (MEM) applications. The actuator is based upon a plurality of meshed electrostatic combs, some of which are stationary and others of which are moveable. One or more restoring springs are fabricated within an outline of the electrostatic combs (i.e. superposed with the moveable electrostatic combs) to considerably reduce the space required for the actuator. Additionally, a truss structure is provided to support the moveable electrostatic combs and prevent bending or distortion of these combs due to unbalanced electrostatic forces or external loading. The truss structure formed about the moveable electrostatic combs allows the spacing between the interdigitated fingers of the combs to be reduced to about one micron or less, thereby substantially increasing the number of active fingers which can be provided in a given area. Finally, electrostatic shields can be used in the actuator to substantially reduce unwanted electrostatic fields to further improve performance of the device. As a result, the compact electrostatic comb actuator of the present invention occupies only a fraction of the space required for conventional electrostatic comb actuators, while providing a substantial increase in the available drive force (up to one-hundred times).

  11. 33 CFR 150.503 - What are the time interval requirements for maintenance on survival craft falls?

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false What are the time interval requirements for maintenance on survival craft falls? 150.503 Section 150.503 Navigation and Navigable Waters... maintenance on survival craft falls? (a) Each fall used in a launching device for survival craft or rescue...

  12. [Processing acoustically presented time intervals of seconds duration: an expression of the phonological loop of the working memory?].

    Science.gov (United States)

    Grube, D

    1996-01-01

    Working memory has been proposed to contribute to the processing of time, rhythm and music; the question which component of working memory is involved is under discussion. The present study tests the hypothesis that the phonological loop component (Baddeley, 1986) is involved in the processing of auditorily presented time intervals of a few seconds' duration. Typical effects well known with short-term retention of verbal material could be replicated with short-term retention of temporal intervals: The immediate reproduction of time intervals was impaired under conditions of background music and articulatory suppression. Neither the accuracy nor the speed of responses in a (non-phonological) mental rotation task were diminished under these conditions. Processing of auditorily presented time intervals seems to be constrained by the capacity of the phonological loop: The immediate serial recall of sequences of time intervals was shown to be related to the immediate serial recall of words (memory span). The results confirm the notion that working memory resources, and especially the phonological loop component, underlie the processing of auditorily presented temporal information with a duration of a few seconds.

  13. Prognostic value of cardiac time intervals measured by tissue Doppler imaging M-mode in the general population

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Jensen, Jan Skov

    2015-01-01

    : In a large prospective community-based study, cardiac function was evaluated in 1915 participants by both conventional echocardiography and TDI. The cardiac time intervals, including the isovolumic relaxation time (IVRT), isovolumic contraction time (IVCT) and ejection time (ET), were obtained by TDI M...

  14. Pre-hospital care time intervals among victims of road traffic injuries in Iran. A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Bigdeli Maryam

    2010-07-01

    Full Text Available Abstract Background Road traffic injuries (RTIs are a major public health problem, requiring concerted efforts both for their prevention and a reduction of their consequences. Timely arrival of the Emergency Medical Service (EMS at the crash scene followed by speedy victim transportation by trained personnel may reduce the RTIs' consequences. The first 60 minutes after injury occurrence - referred to as the "golden hour"- are vital for the saving of lives. The present study was designed to estimate the average of various time intervals occurring during the pre-hospital care process and to examine the differences between these time intervals as regards RTIs on urban and interurban roads. Method A retrospective cross-sectional study was designed and various time intervals in relation to pre-hospital care of RTIs identified in the ambulance dispatch centre in Urmia, Iran from 20 March 2005 to 20 March 2007. All cases which resulted in ambulance dispatches were reviewed and those that had complete data on time intervals were analyzed. Results In total, the cases of 2027 RTI victims were analysed. Of these, 61.5 % of the subjects were injured in city areas. The mean response time for city locations was 5.0 minutes, compared with 10.6 minutes for interurban road locations. The mean on-scene time on the interurban roads was longer than on city roads (9.2 vs. 6.1 minutes, p Conclusion The response, transport and total time intervals among EMS responding to RTI incidents were longer for interurban roads, compared to the city areas. More research should take place on needs-to and access-for EMS on city and interurban roads. The notification interval seems to be a hidden part of the post-crash events and indirectly affects the "golden hour" for victim management and it needs to be measured through the establishment of the surveillance systems.

  15. Is the time interval between surgery and radiotherapy important in operable nonsmall cell lung cancer? A retrospective analysis of 340 cases

    International Nuclear Information System (INIS)

    Wuerschmidt, Florian; Buenemann, Henry; Ehnert, Michael; Heilmann, Hans-Peter

    1997-01-01

    Purpose: To evaluate the influence of prognostic factors in postoperative radiotherapy of NSCLC with special emphasis on the time interval between surgery and start of radiotherapy. Methods and Materials: Between January 1976 and December 1993, 340 cases were treated and retrospectively analyzed meeting the following criteria: complete follow-up; complete staging information including pathological confirmation of resection status; maximum interval between surgery (SX) and radiotherapy (RT) of 12 weeks (median 36 days, range 18 to 84 days); minimum dose of 50 Gy (R0), and maximum dose of 70 Gy (R2). Two hundred thirty patients (68%) had N2 disease; 228 patients were completely resected (R0). One hundred six (31%) had adenocarcinoma, 172 (51%) squamous cell carcinoma. Results: In univariate analysis, Karnofsky performance status (90+ > 60-80%; p = 0.019 log rank), resection status stratified for nodal disease (R+ < R0; p = 0.046), and the time interval between SX and RT were of significant importance. Patients with a long interval (37 to 84 days) had higher 5-year survival rates (26%) and a median survival time (MST: 21.9 months, 95% C.I. 17.2 to 28.6 months) than patients with a short interval (18 to 36 days: 15%; 14.9 months, 13 to 19.9 months; p = 0.013). A further subgroup analysis revealed significant higher survival rates in patients with a long interval in N0/1 disease (p = 0.011) and incompletely resected NSCLC (p = 0.012). In multivariate analysis, the time interval had a p-value of 0.009 (nodal disease: p = 0.0083; KPI: p = 0.0037; sex: p = 0.035). Conclusion: Shortening the time interval between surgery and postoperative radiotherapy to less than 6 weeks even in R+ cases is not necessary. Survival of patients with a long interval between surgery and start of radiotherapy was better in this retrospective analysis as compared to patients with a short interval

  16. Embedding beyond electrostatics

    DEFF Research Database (Denmark)

    Nåbo, Lina J.; Olsen, Jógvan Magnus Haugaard; Holmgaard List, Nanna

    2016-01-01

    We study excited states of cholesterol in solution and show that, in this specific case, solute wave-function confinement is the main effect of the solvent. This is rationalized on the basis of the polarizable density embedding scheme, which in addition to polarizable embedding includes non-electrostatic...... repulsion that effectively confines the solute wave function to its cavity. We illustrate how the inclusion of non-electrostatic repulsion results in a successful identification of the intense π → π∗ transition, which was not possible using an embedding method that only includes electrostatics....... This underlines the importance of non-electrostatic repulsion in quantum-mechanical embedding-based methods....

  17. Specific Electrostatic Molecular Recognition in Water

    DEFF Research Database (Denmark)

    Li, Ming; Hoeck, Casper; Schoffelen, Sanne

    2016-01-01

    The identification of pairs of small peptides that recognize each other in water exclusively through electrostatic interactions is reported. The target peptide and a structure-biased combinatorial ligand library consisting of ≈78 125 compounds were synthesized on different sized beads. Peptide......-bead binding assay and by 2D NMR spectroscopy. Molecular dynamics (MD) studies revealed a putative mode of interaction for this unusual electrostatic binding event. High binding specificity occurred through a combination of topological matching and electrostatic and hydrogen-bond complementarities. From MD...

  18. Evaluation of downmotion time interval molten materials to core catcher during core disruptive accidents postulated in LMFR

    International Nuclear Information System (INIS)

    Voronov, S.A.; Kiryushin, A.I.; Kuzavkov, N.G.; Vlasichev, G.N.

    1994-01-01

    Hypothetical core disruptive accidents are postulated to clear potential of a reactor plant to withstand extreme conditions and to generate measures for management and mitigation of accidents consequence. In Russian advanced reactors there is a core catcher below the diagrid to prevent vessel bottom melting and to localize fuel debris. In this paper the calculation technique and estimation of relocation time of molten fuel and materials are presented in the case of core disruptive accidents postulated for LMFR reactor. To evaluate minimum interval of fuel relocation time the calculations for different initial data are provided. Large mass of materials between the core and the catcher in LMFR reactor hinders molten materials relocation toward the vessel bottom. That condition increases the time interval of reaching core catcher by molten fuel. Computations performed allowed to evaluate the minimum molten materials relocation time from the core to the core catcher. This time interval is in a range of 3.5-5.5 hours. (author)

  19. Using hemoglobin A1C as a predicting model for time interval from pre-diabetes progressing to diabetes.

    Directory of Open Access Journals (Sweden)

    Chen-Ling Huang

    Full Text Available The early identification of subjects at high risk for diabetes is essential, thus, random rather than fasting plasma glucose is more useful. We aim to evaluate the time interval between pre-diabetes to diabetes with anti-diabetic drugs by using HbA1C as a diagnostic tool, and predicting it using a mathematic model.We used the Taipei Medical University Affiliated Hospital Patient Profile Database (AHPPD from January-2007 to June-2011. The patients who progressed and were prescribed anti-diabetic drugs were selected from AHPPD. The mathematical model used to predict the time interval of HbA1C value ranged from 5.7% to 6.5% for diabetes progression.We predicted an average overall time interval for all participants in between 5.7% to 6.5% during a total of 907 days (standard error, 103 days. For each group found among 5.7% to 6.5% we determined 1169.3 days for the low risk group (i.e. 3.2 years, 1080.5 days (i.e. 2.96 years for the increased risk group and 729.4 days (i.e. 1.99 years for the diabetes group. This indicates the patients will take an average of 2.49 years to reach 6.5%.This prediction model is very useful to help prioritize the diagnosis at an early stage for targeting individuals with risk of diabetes. Using patients' HbA1C before anti-diabetes drugs are used we predicted the time interval from pre-diabetes progression to diabetes is 2.49 years without any influence of age and gender. Additional studies are needed to support this model for a long term prediction.

  20. Extension of a chaos control method to unstable trajectories on infinite- or finite-time intervals: Experimental verification

    International Nuclear Information System (INIS)

    Yagasaki, Kazuyuki

    2007-01-01

    In experiments for single and coupled pendula, we demonstrate the effectiveness of a new control method based on dynamical systems theory for stabilizing unstable aperiodic trajectories defined on infinite- or finite-time intervals. The basic idea of the method is similar to that of the OGY method, which is a well-known, chaos control method. Extended concepts of the stable and unstable manifolds of hyperbolic trajectories are used here

  1. Time interval between infective endocarditis first symptoms and diagnosis: relationship to infective endocarditis characteristics, microorganisms and prognosis.

    Science.gov (United States)

    N'Guyen, Yohan; Duval, Xavier; Revest, Matthieu; Saada, Matthieu; Erpelding, Marie-Line; Selton-Suty, Christine; Bouchiat, Coralie; Delahaye, François; Chirouze, Catherine; Alla, François; Strady, Christophe; Hoen, Bruno

    2017-03-01

    To analyze the characteristics and outcome of infective endocarditis (IE) according to the time interval between IE first symptoms and diagnosis. Among the IE cases of a French population-based epidemiological survey, patients having early-diagnosed IE (diagnosis of IE within 1 month of first symptoms) were compared with those having late-diagnosed IE (diagnosis of IE more than 1 month after first symptoms). Among the 486 definite-IE, 124 (25%) had late-diagnosed IE whereas others had early-diagnosed IE. Early-diagnosed IE were independently associated with female gender (OR = 1.8; 95% CI [1.0-3.0]), prosthetic valve (OR= 2.6; 95% CI [1.4-5.0]) and staphylococci as causative pathogen (OR = 3.7; 95% CI [2.2-6.2]). Cardiac surgery theoretical indication rates were not different between early and late-diagnosed IE (56.3% vs 58.9%), whereas valve surgery performance was lower in early-diagnosed IE (41% vs 53%; p = .03). In-hospital mortality rates were higher in early-diagnosed IE than in late-diagnosed IE (25.1% vs 16.1%; p endocarditis, which time interval between first symptoms and diagnosis was less than one month, were mainly due to Staphylococcus aureus in France. Staphylococcus aureus infective endocarditis were associated with septic shock, transient ischemic attack or stroke and higher mortality rates than infective endocarditis due to other bacteria or infective endocarditis, which time interval between first symptoms and diagnosis was more than one month. Infective endocarditis, which time interval between first symptoms and diagnosis was more than one month, were accounting for one quarter of all infective endocarditis in our study and were associated with vertebral osteomyelitis and a higher rate of cardiac surgery performed for hemodynamic indication than other infective endocarditis.

  2. Influence of remineralizing gels on bleached enamel microhardness in different time intervals.

    Science.gov (United States)

    Borges, Alessandra Bühler; Yui, Karen Cristina Kazue; D'Avila, Thaís Corrêa; Takahashi, Camila Lurie; Torres, Carlos Rocha Gomes; Borges, Alexandre Luis Souto

    2010-01-01

    This study evaluated the influence of bleaching gel pH, the effect of applying remineralizing gels after bleaching and the effect of artificial saliva on enamel microhardness. Seventy bovine incisors were divided into three groups: Group 1 (n=10) received no bleaching procedure (control); Group 2 was bleached with a 35% hydrogen peroxide neutral gel (n=30) and Group 3 was bleached with a 35% hydrogen peroxide acid gel (n=30). Each experimental group was subdivided into three groups (n=10) according to the post-bleaching treatment: storage in artificial saliva, application of a fluoride gel and application of a combination of calcium and fluoride gel. The specimens were stored in artificial saliva for 7, 15 and 30 days and enamel microhardness was evaluated. The Vickers microhardness data were analyzed by three-way RM ANOVA, which revealed a significant difference only for treatment factor. The Tukey's test showed that the groups bleached followed by no additional treatment exhibited microhardness means significantly lower than the bleached groups treated with remineralizing gels. The Dunnet's test showed a significant difference only for the group bleached with acid gel without remineralizing treatment compared to the control group measured immediately after bleaching. It was concluded that acid bleaching gel significantly reduced enamel microhardness and that use of remineralizing gels after bleaching can significantly enhance the microhardness of bleached enamel.

  3. Effect of insertion method and postinsertion time interval prior to force application on the removal torque of orthodontic miniscrews.

    Science.gov (United States)

    Sharifi, Maryam; Ghassemi, Amirreza; Bayani, Shahin

    2015-01-01

    Success of orthodontic miniscrews in providing stable anchorage is dependent on their stability. The purpose of this study was to assess the effect of insertion method and postinsertion time interval on the removal torque of miniscrews as an indicator of their stability. Seventy-two miniscrews (Jeil Medical) were inserted into the femoral bones of three male German Shepherd dogs and assigned to nine groups of eight miniscrews. Three insertion methods, including hand-driven, motor-driven with 5.0-Ncm insertion torque, and motor-driven with 20.0-Ncm insertion torque, were tested. Three time intervals of 0, 2, and 6 weeks between miniscrew insertion and removal were tested as well. Removal torque values were measured in newton centimeters by a removal torque tester (IMADA). Data were analyzed by one-way analysis of variance (ANOVA) followed by the Bonferroni post hoc test at a .05 level of significance. A miniscrew survival rate of 93% was observed in this study. The highest mean value of removal torque among the three postinsertion intervals (2.4 ± 0.59 Ncm) was obtained immediately after miniscrew insertion with a statistically significant difference from the other two time intervals (P torque values were obtained immediately after insertion.

  4. Contrasting Perspectives of Anesthesiologists and Gastroenterologists on the Optimal Time Interval between Bowel Preparation and Endoscopic Sedation

    Directory of Open Access Journals (Sweden)

    Deepak Agrawal

    2015-01-01

    Full Text Available Background. The optimal time interval between the last ingestion of bowel prep and sedation for colonoscopy remains controversial, despite guidelines that sedation can be administered 2 hours after consumption of clear liquids. Objective. To determine current practice patterns among anesthesiologists and gastroenterologists regarding the optimal time interval for sedation after last ingestion of bowel prep and to understand the rationale underlying their beliefs. Design. Questionnaire survey of anesthesiologists and gastroenterologists in the USA. The questions were focused on the preferred time interval of endoscopy after a polyethylene glycol based preparation in routine cases and select conditions. Results. Responses were received from 109 anesthesiologists and 112 gastroenterologists. 96% of anesthesiologists recommended waiting longer than 2 hours until sedation, in contrast to only 26% of gastroenterologists. The main reason for waiting >2 hours was that PEG was not considered a clear liquid. Most anesthesiologists, but not gastroenterologists, waited longer in patients with history of diabetes or reflux. Conclusions. Anesthesiologists and gastroenterologists do not agree on the optimal interval for sedation after last drink of bowel prep. Most anesthesiologists prefer to wait longer than the recommended 2 hours for clear liquids. The data suggest a need for clearer guidelines on this issue.

  5. Edutainment Science: Electrostatics

    Science.gov (United States)

    Ahlers, Carl

    2009-01-01

    Electrostatics should find a special place in all primary school science curricula. It is a great learning area that reinforces the basics that underpin electricity and atomic structure. Furthermore, it has many well documented hands-on activities. Unfortunately, the "traditional" electrostatics equipment such as PVC rods, woollen cloths, rabbit…

  6. Electrostatic septum, SPS

    CERN Multimedia

    CERN PhotoLab

    1978-01-01

    To minimize losses during slow extraction towards N- and W-Area, electrostatic septa in long straight sections 2 and 6 precede the magnetic septa. This picture shows such an electrostatic septum in its tank. See 7501120X, 7501199 and 7501201 for more detailed pictures.

  7. Collisionless electrostatic shocks

    DEFF Research Database (Denmark)

    Andersen, H.K.; Andersen, S.A.; Jensen, Vagn Orla

    1970-01-01

    An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth......An attempt was made in the laboratory to observe the standing collisionless electrostatic shocks in connection with the bow shock of the earth...

  8. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    characteristics and applications of the electrostatic potential of many-electron atoms, ions and molecules are discussed. Electrostatic Potential of Atoms and Singly. Charged ..... [6] R K Pathak and S R Gadre,J. Chat. Phys., 93, 1770, 1990. [7] S R Gadre, S A Kalkarni and I H Shrivastava,J. Chern. Phys., 96,52;3,. 1992. ~ .1.

  9. Pre-hospital care time intervals among victims of road traffic injuries in Iran. A cross-sectional study.

    Science.gov (United States)

    Bigdeli, Maryam; Khorasani-Zavareh, Davoud; Mohammadi, Reza

    2010-07-09

    Road traffic injuries (RTIs) are a major public health problem, requiring concerted efforts both for their prevention and a reduction of their consequences. Timely arrival of the Emergency Medical Service (EMS) at the crash scene followed by speedy victim transportation by trained personnel may reduce the RTIs' consequences. The first 60 minutes after injury occurrence--referred to as the "golden hour"--are vital for the saving of lives. The present study was designed to estimate the average of various time intervals occurring during the pre-hospital care process and to examine the differences between these time intervals as regards RTIs on urban and interurban roads. A retrospective cross-sectional study was designed and various time intervals in relation to pre-hospital care of RTIs identified in the ambulance dispatch centre in Urmia, Iran from 20 March 2005 to 20 March 2007. All cases which resulted in ambulance dispatches were reviewed and those that had complete data on time intervals were analyzed. In total, the cases of 2027 RTI victims were analysed. Of these, 61.5% of the subjects were injured in city areas. The mean response time for city locations was 5.0 minutes, compared with 10.6 minutes for interurban road locations. The mean on-scene time on the interurban roads was longer than on city roads (9.2 vs. 6.1 minutes, p transport times from the scene to the hospital were also significantly longer for interurban incidents (17.1 vs. 6.3 minutes, p transport and total time intervals among EMS responding to RTI incidents were longer for interurban roads, compared to the city areas. More research should take place on needs-to and access-for EMS on city and interurban roads. The notification interval seems to be a hidden part of the post-crash events and indirectly affects the "golden hour" for victim management and it needs to be measured through the establishment of the surveillance systems.

  10. Electrostatic Detumble of Space Objects

    Data.gov (United States)

    National Aeronautics and Space Administration — Electrostatic Tractor Technology research explores the harmony of physics and engineering to develop and test electrostatic actuation methods for touchless detumble...

  11. Time interval between maternal electrocardiogram and venous Doppler waves in normal pregnancy and preeclampsia: a pilot study.

    Science.gov (United States)

    Tomsin, K; Mesens, T; Molenberghs, G; Peeters, L; Gyselaers, W

    2012-12-01

    To evaluate the time interval between maternal electrocardiogram (ECG) and venous Doppler waves at different stages of uncomplicated pregnancy (UP) and in preeclampsia (PE). Cross-sectional pilot study in 40 uncomplicated singleton pregnancies, categorized in four groups of ten according to gestational age: 10 - 14 weeks (UP1), 18 - 23 weeks (UP2), 28 - 33 weeks (UP3) and ≥ 37 weeks (UP4) of gestation. A fifth group of ten women with PE was also included. A Doppler flow examination at the level of renal interlobar veins (RIV) and hepatic veins (HV) was performed according to a standard protocol, in association with a maternal ECG. The time interval between the ECG P-wave and the corresponding A-deflection of the venous Doppler waves was measured (PA), and expressed relative to the duration of the cardiac cycle (RR), and labeled PA/RR. In hepatic veins, the PA/RR is longer in UP 4 than in UP 1 (0.48 ± 0.15 versus 0.29 ± 0.09, p ≤ 0.001). When all UP groups were compared, the PA/RR increased gradually with gestational age. In PE, the HV PA/RR is shorter than in UP 3 (0.25 ± 0.09 versus 0.42 ± 0.14, p advanced gestational stages are consistent with known features of maternal cardiovascular adaptation. Shorter values in preeclampsia are consistent with maternal cardiovascular maladaptation mechanisms. Our pilot study invites more research of the relevance of the time interval between maternal ECG and venous Doppler waves as a new parameter for studying the gestational cardiovascular (patho)physiology of the maternal venous compartment by duplex sonography. © Georg Thieme Verlag KG Stuttgart · New York.

  12. The influence of the anesthesia-to-stimulation time interval on seizure quality parameters in electroconvulsive therapy

    DEFF Research Database (Denmark)

    Jorgensen, A; Christensen, S J; Jensen, A E K

    2018-01-01

    BACKGROUND: Electroconvulsive therapy (ECT) continues to be the most efficacious treatment for severe depression and other life-threatening acute psychiatric conditions. Treatment efficacy is dependent upon the induced seizure quality, which may be influenced by a range of treatment related factors....... Recently, the time interval from anesthesia to the electrical stimulation (ASTI) has been suggested to be an important determinant of seizure quality. METHODS: We measured ASTI in 73 ECT sessions given to 22 individual patients, and analyzed its influence on five seizure quality parameters (EEG seizure...

  13. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1982-01-01

    Electrostatic pickup station, with 4 interleaved electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TT70, TTL2). See also 7904075.

  14. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    fundamental concepts of electrostatics as applied to atoms and molecules. The electric ... chemistry, the chemistry of the covalent bond, deals with the structures ..... the position of an asteroid named Ceres ... World Scientific. Singapore, 1992.

  15. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    International Nuclear Information System (INIS)

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-01-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p ≤ 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  16. The use of a DNA stabilizer in human dental tissues stored under different temperature conditions and time intervals

    Science.gov (United States)

    TERADA, Andrea Sayuri Silveira Dias; da SILVA, Luiz Antonio Ferreira; GALO, Rodrigo; de AZEVEDO, Aline; GERLACH, Raquel Fernanda; da SILVA, Ricardo Henrique Alves

    2014-01-01

    Objective The present study evaluated the use of a reagent to stabilize the DNA extracted from human dental tissues stored under different temperature conditions and time intervals. Material and Methods A total of 161 teeth were divided into two distinct groups: intact teeth and isolated dental pulp tissue. The samples were stored with or without the product at different time intervals and temperature. After storage, DNA extraction and genomic DNA quantification were performed using real-time PCR; the fragments of the 32 samples that represented each possible condition were analyzed to find the four pre-selected markers in STR analysis. Results The results of the quantification showed values ranging from 0.01 to 10,246.88 ng/μL of DNA. The statistical difference in the quantity of DNA was observed when the factors related to the time and temperature of storage were analyzed. In relation to the use of the specific reagent, its use was relevant in the group of intact teeth when they were at room temperature for 30 and 180 days. The analysis of the fragments in the 32 selected samples was possible irrespective of the amount of DNA, confirming that the STR analysis using an automated method yields good results. Conclusions The use of a specific reagent showed a significant difference in stabilizing DNA in samples of intact human teeth stored at room temperature for 30 and 180 days, while the results showed no justification for using the product under the other conditions tested. PMID:25141206

  17. The Effect of Fluoridated and Non Fluoridated Mouth Washes on Color Stability of Different Aesthetic Arch Wires At Different Time Intervals (An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Lubna Maky Hussein

    2018-01-01

    Full Text Available Background:The color stability of aesthetic arch wires is an important factor in the success of an aesthetic orthodontic treatment, but the color of these arch wires tends to change with time.This study was performed to assess the effect of two types of mouth washes on the color  stability of different types of aesthetic arch wires at different time intervals. Materials and methods:Four brands of nickel titanium coated aesthetic arch wires were used: epoxy coated (Orthotechnology and G&H and Teflon coated (Dany and Hubit.Thirty six samples were prepared, each sample contains ten halves of the aesthetic arch wires. They were divided into three groups according to the immersion media (distilled water as a control media, Listerine with fluoride and Listerine without fluoride and immersed for 30 seconds twice daily according to manufacturer's instructions to measure color change after 1 week, 3 weeks and 6 weeks by using spectrophotometer VITA Easyshade Compact according to Commission Internationale de l’Eclairage L*a*b* color space system. Results:It was found that there were highly significant differences in color change values of aesthetic arch wires among all immersion media at different time intervals and color change value increases as the time of immersion increases.Additionally, Listerine with fluoride mouth wash caused higher color change values of aesthetic arch wires than Listerine without fluoride and Hubit aesthetic arch wires were the least color stable while Orthotechnology aesthetic arch wires were the most color stable. Conclusions: We can conclude that the daily use of Listerine mouth washes could affect on the color stability of aesthetic arch wires. Although all tested aesthetic arch wires revealed color changes at variable degrees but some of these changes were not  visible and the others were clinically acceptable while the remaining were clinically unacceptable.

  18. Electrostatic Levitator Electrode Layout

    Science.gov (United States)

    1998-01-01

    Schematic of Electrostatic Levitator (ESL) electrodes and controls system. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  19. Electrostatic Levitator Layout

    Science.gov (United States)

    1998-01-01

    Electrostatic Levitator (ESL) general layout with captions. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  20. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed...

  1. Probing lipid membrane electrostatics

    Science.gov (United States)

    Yang, Yi

    The electrostatic properties of lipid bilayer membranes play a significant role in many biological processes. Atomic force microscopy (AFM) is highly sensitive to membrane surface potential in electrolyte solutions. With fully characterized probe tips, AFM can perform quantitative electrostatic analysis of lipid membranes. Electrostatic interactions between Silicon nitride probes and supported zwitterionic dioleoylphosphatidylcholine (DOPC) bilayer with a variable fraction of anionic dioleoylphosphatidylserine (DOPS) were measured by AFM. Classical Gouy-Chapman theory was used to model the membrane electrostatics. The nonlinear Poisson-Boltzmann equation was numerically solved with finite element method to provide the potential distribution around the AFM tips. Theoretical tip-sample electrostatic interactions were calculated with the surface integral of both Maxwell and osmotic stress tensors on tip surface. The measured forces were interpreted with theoretical forces and the resulting surface charge densities of the membrane surfaces were in quantitative agreement with the Gouy-Chapman-Stern model of membrane charge regulation. It was demonstrated that the AFM can quantitatively detect membrane surface potential at a separation of several screening lengths, and that the AFM probe only perturbs the membrane surface potential by external field created by the internai membrane dipole moment. The analysis yields a dipole moment of 1.5 Debye per lipid with a dipole potential of +275 mV for supported DOPC membranes. This new ability to quantitatively measure the membrane dipole density in a noninvasive manner will be useful in identifying the biological effects of the dipole potential. Finally, heterogeneous model membranes were studied with fluid electric force microscopy (FEFM). Electrostatic mapping was demonstrated with 50 nm resolution. The capabilities of quantitative electrostatic measurement and lateral charge density mapping make AFM a unique and powerful

  2. Detection of surface electromyography recording time interval without muscle fatigue effect for biceps brachii muscle during maximum voluntary contraction.

    Science.gov (United States)

    Soylu, Abdullah Ruhi; Arpinar-Avsar, Pinar

    2010-08-01

    The effects of fatigue on maximum voluntary contraction (MVC) parameters were examined by using force and surface electromyography (sEMG) signals of the biceps brachii muscles (BBM) of 12 subjects. The purpose of the study was to find the sEMG time interval of the MVC recordings which is not affected by the muscle fatigue. At least 10s of force and sEMG signals of BBM were recorded simultaneously during MVC. The subjects reached the maximum force level within 2s by slightly increasing the force, and then contracted the BBM maximally. The time index of each sEMG and force signal were labeled with respect to the time index of the maximum force (i.e. after the time normalization, each sEMG or force signal's 0s time index corresponds to maximum force point). Then, the first 8s of sEMG and force signals were divided into 0.5s intervals. Mean force, median frequency (MF) and integrated EMG (iEMG) values were calculated for each interval. Amplitude normalization was performed by dividing the force signals to their mean values of 0s time intervals (i.e. -0.25 to 0.25s). A similar amplitude normalization procedure was repeated for the iEMG and MF signals. Statistical analysis (Friedman test with Dunn's post hoc test) was performed on the time and amplitude normalized signals (MF, iEMG). Although the ANOVA results did not give statistically significant information about the onset of the muscle fatigue, linear regression (mean force vs. time) showed a decreasing slope (Pearson-r=0.9462, pfatigue starts after the 0s time interval as the muscles cannot attain their peak force levels. This implies that the most reliable interval for MVC calculation which is not affected by the muscle fatigue is from the onset of the EMG activity to the peak force time. Mean, SD, and range of this interval (excluding 2s gradual increase time) for 12 subjects were 2353, 1258ms and 536-4186ms, respectively. Exceeding this interval introduces estimation errors in the maximum amplitude calculations

  3. Magnetosheath electrostatic turbulence

    International Nuclear Information System (INIS)

    Rodriguez, P.

    1979-01-01

    By using measurements with the University of Iowa plasma wave experiment on the Imp 6 satellite a study has been conducted of the spectrum of electrostatic plasma waves in the terrestrial magnetosheath. Electrostatic plasma wave turbulence is almost continuously present throughout the magnetosheath with broadband (20 Hz to 70 kHz) rms field intensities typically 0.01--1.0 mV m -1 . Peak intensities of about 1.0 mV m -1 near the electron plasma frequency (30--60 kHz) have been detected occasionally. Two or three components can usually be identified in the spectrum of magnetosheath electrostatic turbulence: a high-frequency (> or =30kHz) component peaking at the electron plasma frequency f/sub p/e, a low-frequency component with a broad intensity maximum below the nominal ion plasma frequency f/sub p/i (approx. f/sub p/e/43), and a less well defined intermediate component in the range f/sub p/i < f< f/sub p/e. The intensity distribution of magnetosheath electrostatic turbulence clearly shows that the low-frequency component is associated with the bow shock, suggesting that the ion heating begun at the shock continues into the downstream magnetosheath. Electrostatic waves below 1 kHz are polarized along the magnetic field direction, a result consistent with the polarization of electrostatic waves at the shock. The high- and intermediate-frequency components are features of the magnetosheath spectrum which are not characteristic of the shock spectrum but are often detected in the upstream solar wind. The intensity distribution of electrostatic turbulence at the magnetosheath plasma frequency has no apparent correlation with the shock, indicating that electron plasma oscillations are a general feature of the magnetosheath. The plasma wave noise shows a tendency to decrease toward the dawn and dusk regions, consistent with a general decrease in turbulence away from the subsolar magnetosheath

  4. Robust L2-L∞ Filtering of Time-Delay Jump Systems with Respect to the Finite-Time Interval

    Directory of Open Access Journals (Sweden)

    Shuping He

    2011-01-01

    Full Text Available This paper studied the problem of stochastic finite-time boundedness and disturbance attenuation for a class of linear time-delayed systems with Markov jumping parameters. Sufficient conditions are provided to solve this problem. The L2-L∞ filters are, respectively, designed for time-delayed Markov jump linear systems with/without uncertain parameters such that the resulting filtering error dynamic system is stochastically finite-time bounded and has the finite-time interval disturbance attenuation γ for all admissible uncertainties, time delays, and unknown disturbances. By using stochastic Lyapunov-Krasovskii functional approach, it is shown that the filter designing problem is in terms of the solutions of a set of coupled linear matrix inequalities. Simulation examples are included to demonstrate the potential of the proposed results.

  5. On the reconstruction of inclusions in a heat conductive body from dynamical boundary data over a finite time interval

    International Nuclear Information System (INIS)

    Ikehata, Masaru; Kawashita, Mishio

    2010-01-01

    The enclosure method was originally introduced for inverse problems concerning non-destructive evaluation governed by elliptic equations. It was developed as one of the useful approaches in inverse problems and applied for various equations. In this paper, an application of the enclosure method to an inverse initial boundary value problem for a parabolic equation with a discontinuous coefficient is given. A simple method to extract the depth of unknown inclusions in a heat conductive body from a single set of the temperature and heat flux on the boundary observed over a finite time interval is introduced. Other related results with infinitely many data are also reported. One of them gives the minimum radius of the open ball centred at a given point that contains the inclusions. The formula for the minimum radius is newly discovered

  6. The impact of the time interval on in-vitro fertilisation success after failure of the first attempt.

    Science.gov (United States)

    Bayoglu Tekin, Y; Ceyhan, S T; Kilic, S; Korkmaz, C

    2015-05-01

    The aim of this study was to identify the optimal time interval for in-vitro fertilisation that would increase treatment success after failure of the first attempt. This retrospective study evaluated 454 consecutive cycles of 227 infertile women who had two consecutive attempts within a 6-month period at an IVF centre. Data were collected on duration of stimulation, consumption of gonadotropin, numbers of retrieved oocytes, mature oocytes, fertilised eggs, good quality embryos on day 3/5 following oocyte retrieval and clinical and ongoing pregnancy. There were significant increases in clinical pregnancy rates at 2-, 3- and 4-month intervals. The maximum increase was after two menstrual cycles (p = 0.001). The highest rate of ongoing pregnancy was in women that had the second attempt after the next menstrual cycle following failure of IVF (27.2%). After IVF failure, initiating the next attempt within 2-4 months increases the clinical pregnancy rates.

  7. Modular 125 ps resolution time interval digitizer for 10 MHz stop burst rates and 33 ms range

    International Nuclear Information System (INIS)

    Turko, B.

    1978-01-01

    A high resolution multiple stop time interval digitizer is described. It is capable of resolving stop burst rates of up to 10 MHz with an incremental resolution of 125 ps within a range of 33 ms. The digitizer consists of five CAMAC modules and uses a standard CAMAC crate and controller. All the functions and ranges are completely computer controlled. Any two subsequent stop pulses in a burst can be resolved within 100 ns due to a new dual interpolation technique employed. The accuracy is maintained by a high stability 125 MHz reference clock. Up to 131 stop events can be stored in a 48-bit, 10 MHz derandomizing storage register before the digitizer overflows. The experimental data are also given

  8. Time interval measurement between to emission: a systematics; Mesure de l`intervalle de temps entre deux emissions: une systematique

    Energy Technology Data Exchange (ETDEWEB)

    Bizard, G.; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Kerambrun, A.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lopez, O.; Louvel, M.; Mahi, M.; Meslin, C.; Steckmeyer, J.C.; Tamain, B.; Wieloch, A. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France); LPC (Caen) - CRN (Strasbourg) Collaboration

    1998-04-01

    A systematic study of the evolution of intervals of fragment emission times as a function of the energy deposited in the compound system was performed. Several measurements, Ne at 60 MeV/u, Ar at 30 and 60 MeV/u and two measurements for Kr at 60 MeV/u (central and semi-peripheral collisions) are presented. In all the experiments the target was Au and the mass of the compounds system was around A = 200. The excitation energies per nucleon reached in the case of these heavy systems cover the range of 3 to 5.5 MeV/u. The method used to determine the emission time intervals is based on the correlation functions associated to the relative angle distributions. The gaps between the data and simulations allow to evaluate the emission times. A rapid decrease of these time intervals was observed when the excitation energy increased. This variation starts at 500 fm/c which corresponds to a sequential emission. This relatively long time which indicates a weak interaction between fragments, corresponds practically to the measurement threshold. The shortest intervals (about 50 fm/c) are associated to a spontaneous multifragmentation and were observed in the case of central collisions at Ar+Au and Kr+Au at 60 MeV/u. Two interpretations are possible. The multifragmentation process might be viewed as a sequential process of very short time-separation or else, one can separate two zones heaving in mind that the multifragmentation is predominant from 4,5 MeV/u excitation energy upwards. This question is still open and its study is under way at LPC. An answer could come from the study of the rupture process of an excited nucleus, notably by the determination of its life-time

  9. OPTIMASI OLSR ROUTING PROTOCOL PADA JARINGAN WIRELESS MESH DENGAN ADAPTIVE REFRESHING TIME INTERVAL DAN ENHANCE MULTI POINT RELAY SELECTING ALGORITHM

    Directory of Open Access Journals (Sweden)

    Faosan Mapa

    2014-01-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Wireless Mesh Network (WMN adalah suatu konektivitas jaringan yang self-organized, self-configured dan multi-hop. Tujuan dari WMN adalah menawarkan pengguna suatu bentuk jaringan nirkabel yang dapat dengan mudah berkomunikasi dengan jaringan konvensional dengan kecepatan tinggi dan dengan cakupan yang lebih luas serta biaya awal yang minimal. Diperlukan suatu desain protokol routing yang efisien untuk WMN yang secara adaptif dapat mendukung mesh routers dan mesh clients. Dalam tulisan ini, diusulkan untuk mengoptimalkan protokol OLSR, yang merupakan protokol routing proaktif. Digunakan heuristik yang meningkatkan protokol OLSR melalui adaptive refreshing time interval dan memperbaiki metode MPR selecting algorithm. Suatu analisa dalam meningkatkan protokol OLSR melalui adaptive refreshing time interval dan memperbaiki algoritma pemilihan MPR menunjukkan kinerja yang signifikan dalam hal throughput jika dibandingkan dengan protokol OLSR yang asli. Akan tetapi, terdapat kenaikan dalam hal delay. Pada simulasi yang dilakukan dapat disimpulkan bahwa OLSR dapat dioptimalkan dengan memodifikasi pemilihan node MPR berdasarkan cost effective dan penyesuaian waktu interval refreshing hello message sesuai dengan keadaan

  10. Effect of palady and cup feeding on premature neonates′ weight gain and reaching full oral feeding time interval

    Directory of Open Access Journals (Sweden)

    Maryam Marofi

    2016-01-01

    Full Text Available Background: Premature neonates′ feeding is of great importance due to its effective role in their growth. These neonates should reach an independent oral nutrition stage before being discharged from the Neonatal Intensive care Unit. Therefore, the researcher decided to conduct a study on the effect of palady and cup feeding on premature neonates′ weight gain and their reaching full oral feeding time interval. Materials and Methods: This is a clinical trial with a quantitative design conducted on 69 premature infants (gestational age between 29 and 32 weeks who were assigned to cup (n = 34 and palady (n = 35 feeding groups through random allocation. The first feeding was administrated either by cup or palady method in each shift within seven sequential days (total of 21 cup and palady feedings. Then, the rest of feeding was administrated by gavage. Results: Mean hospitalization time (cup = 39.01 and palady = 30.4; P < 0.001 and mean time interval to reach full oral feeding (cup = 33.7 and palady = 24.1; P < 0.001 were significantly lower in palady group compared to cup group. Mean weight changes of neonates 7 weeks after the intervention compared to those in the beginning of the intervention were significantly more in palady group compared to the cup group (cup = 146.7 and palady = 198.8; P < 0.001. Conclusions: The neonates in palady group reached full oral feeding earlier than those of cup group. Subjects′ weight gain was also higher in palady group compared to the cup group. Premature neonates with over 30 weeks of gestational age and physiological stability can be fed by palady.

  11. Large electrostatic accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators.

  12. Large electrostatic accelerators

    International Nuclear Information System (INIS)

    Jones, C.M.

    1984-01-01

    The increasing importance of energetic heavy ion beams in the study of atomic physics, nuclear physics, and materials science has partially or wholly motivated the construction of a new generation of large electrostatic accelerators designed to operate at terminal potentials of 20 MV or above. In this paper, the author briefly discusses the status of these new accelerators and also discusses several recent technological advances which may be expected to further improve their performance. The paper is divided into four parts: (1) a discussion of the motivation for the construction of large electrostatic accelerators, (2) a description and discussion of several large electrostatic accelerators which have been recently completed or are under construction, (3) a description of several recent innovations which may be expected to improve the performance of large electrostatic accelerators in the future, and (4) a description of an innovative new large electrostatic accelerator whose construction is scheduled to begin next year. Due to time and space constraints, discussion is restricted to consideration of only tandem accelerators

  13. Microscopic models for bridging electrostatics and currents

    Science.gov (United States)

    Borghi, L.; DeAmbrosis, A.; Mascheretti, P.

    2007-03-01

    A teaching sequence based on the use of microscopic models to link electrostatic phenomena with direct currents is presented. The sequence, devised for high school students, was designed after initial work carried out with student teachers attending a school of specialization for teaching physics at high school, at the University of Pavia. The results obtained with them are briefly presented, because they directed our steps for the development of the teaching sequence. For both the design of the experiments and their interpretation, we drew inspiration from the original works of Alessandro Volta; in addition, a structural model based on the particular role of electrons as elementary charges both in electrostatic phenomena and in currents was proposed. The teaching sequence starts from experiments on charging objects by rubbing and by induction, and engages students in constructing microscopic models to interpret their observations. By using these models and by closely examining the ideas of tension and capacitance, the students acknowledge that a charging (or discharging) process is due to the motion of electrons that, albeit for short time intervals, represent a current. Finally, they are made to see that the same happens in transients of direct current circuits.

  14. Advances in electrostatic accelerators

    International Nuclear Information System (INIS)

    Wegner, H.E.

    1975-01-01

    Advances in the design and performance of electrostatic accelerators since 1969 are reviewed with special emphasis on the ''forefront'' accelerators that are currently leading in voltage capability. A comparison of the acceleration tube design offered by the National Electrostatics Corporation and the High Voltage Engineering Corporation is also made. Other methods of increasing heavy ion energy by means of dual foil stripping are discussed as well as the performance of a newly developed sputter ion source for the production of negative heavy ions with reliability and flexibility that greatly exceeds all other present systems. Finally, new developments in terms of both booster systems and very high voltage electrostatic accelerators (25 to 60 MV) are discussed. (U.S.)

  15. Electrostatic beneficiation of coal

    Energy Technology Data Exchange (ETDEWEB)

    Mazumder, M.K.; Tennal, K.B.; Lindquist, D.

    1994-10-01

    Dry physical beneficiation of coal has many advantages over wet cleaning methods and post combustion flue gas cleanup processes. The dry beneficiation process is economically competitive and environmentally safe and has the potential of making vast amounts of US coal reserves available for energy generation. While the potential of the electrostatic beneficiation has been studied for many years in laboratories and in pilot plants, a successful full scale electrostatic coal cleaning plant has not been commercially realized yet. In this paper the authors review some of the technical problems that are encountered in this method and suggest possible solutions that may lead toward its full utilization in cleaning coal.

  16. Electrostatic septum, SPS

    CERN Multimedia

    1975-01-01

    To minimize losses during slow extraction towards N- and W-Areas, electrostatic septa in long straight sections 2 an 6 precede the magnetic septa. The 2 electrode plates, visible at the entrance to the septum, provide a vertical electric field to remove the ions created by the circulating beam in the residual gas. Here we see one of the electrostatic septa being assembled by Faustin Emery (left) and Jacques Soubeyran (right), in the clean room of building 867. See also 7501199, 7501201, 7801286 and further explanations there.

  17. Aspectos cognitivos relacionados à noção de intervalos de tempo Cognitive aspects related to time interval notion

    Directory of Open Access Journals (Sweden)

    Liliane Cristina de Além-Mar e Silva

    2007-01-01

    Full Text Available OBJETIVO: Procuramos analisar os aspectos cognitivos e metodológicos envolvidos na avaliação da noção de intervalos de tempo, verificando os aspectos cognitivos envolvidos durante a sua execução, e apontar a relevância, aplicabilidade e sensibilidade dessa avaliação no exame neuropsicológico. MÉTODOS: Realizou-se revisão bibliográfica abrangendo artigos e pesquisas das literaturas nacional e internacional no período de 1990 a 2005. RESULTADOS: Encontraram-se 13 diferentes estudos. São controversas as discussões acerca de teorias sobre a noção de tempo. Os estudos podem ser agrupados de acordo com duas perspectivas diferentes: a teoria da contagem atencional, de grande utilização por pesquisadores americanos, e a teoria do relógio interno, muito abordada por estudiosos franceses que se diferem tanto em relação à abordagem teórica quanto à metodológica. CONCLUSÕES: Ambos os grupos de pesquisa, americanos e franceses, retratam a relevância da aplicação dos testes de estimativa, reprodução e produção de tempo no estudo das funções executivas.OBJECTIVE: We tried to analyze the cognitive and methodological aspects involved in the evaluation of time intervals notion, verifying the cognitive aspects involved during your execution, and to point the relevance, applicability and sensibility of this evaluation in the neuropsychologic exam. METHODS: Bibliographical revision was accomplished including articles and researches of the national and international literature in the period of 1990 to 2005. RESULTS: Were found 13 different researches. The discussions concerning theories about the time notion are controversial. These studies can be grouped into two different perspectives: the attentional counter theory, used by American researchers, and the internal clock theory, very boarded by French studious, that are differed in relation to the theoretical and to the methodological approaches. CONCLUSIONS: Both research groups

  18. Versatile electrostatic trap

    NARCIS (Netherlands)

    van Veldhoven, J.; Bethlem, H.L.; Schnell, M.; Meijer, G.

    2006-01-01

    A four electrode electrostatic trap geometry is demonstrated that can be used to combine a dipole, quadrupole, and hexapole field. A cold packet of ND315 molecules is confined in both a purely quadrupolar and hexapolar trapping field and additionally, a dipole field is added to a hexapole field to

  19. Electrostatics in Chemistry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 2. Electrostatics in Chemistry - Basic Principles. Shridhar R Gadre Pravin K Bhadane. Series Article Volume 4 Issue 2 February 1999 pp 8-19. Fulltext. Click here to view fulltext PDF. Permanent link:

  20. Electrostatic shielding of transformers

    Energy Technology Data Exchange (ETDEWEB)

    De Leon, Francisco

    2017-11-28

    Toroidal transformers are currently used only in low-voltage applications. There is no published experience for toroidal transformer design at distribution-level voltages. Toroidal transformers are provided with electrostatic shielding to make possible high voltage applications and withstand the impulse test.

  1. Electrostatic septum, SPS

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    To minimize losses during slow extraction towards N- and W-Area, electrostatic septa in long straight sections 2 and 6 precede the magnetic septa. This picture is a detail of 7501199, and shows the suspension of the wires. 7801286 shows a septum in its tank. See also 7501120X.

  2. Electrostatic pickup station

    CERN Multimedia

    CERN PhotoLab

    1979-01-01

    Electrostatic pickup station, with 4 electrodes, to measure beam position in the horizontal and vertical plane. This type is used in the transfer lines leaving the PS (TT2, TTL2, TT70). See also 8206063, where the electrode shapes are clearly visible.

  3. Time interval measurement between two emissions: Kr + Au; Mesure de l`intervalle de temps entre deux emissions: Kr + Au

    Energy Technology Data Exchange (ETDEWEB)

    Aboufirassi, M; Bougault, R.; Brou, R.; Colin, J.; Durand, D.; Genoux-Lubain, A.; Horn, D.; Laville, J.L.; Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; Lopez, O.; Louvel, M.; Mahi, M.; Steckmeyer, J.C.; Tamain, B. [Lab. de Physique Corpusculaire, Caen Univ., 14 (France); LPC (Caen) - CRN (Strasbourg) - GANIL Collaboration

    1998-04-01

    To indicate the method allowing the determination of the emission intervals, the results obtained with the Kr + Au system at 43 and 60 A.MeV are presented. The experiments were performed with the NAUTILUS exclusive detectors. Central collisions were selected by means of a relative velocity criterion to reject the events containing a forward emitted fragment. For the two bombardment energies the data analysis shows that the formation of a compound of mass around A = 200. By comparing the fragment dynamical variables with simulations one can conclude about the simultaneity of the compound deexcitation processes. It was found that a 5 MeV/A is able to reproduce the characteristics of the detected fragments. Also, it was found that to reproduce the dynamical characteristics of the fragments issued from central collisions it was not necessary to superimpose a radial collective energy upon the Coulomb and thermal motion. The distribution of the relative angles between detected fragments is used here as a chronometer. For simultaneous ruptures the small relative angles are forbidden by the Coulomb repulsion, while for sequential processes this interdiction is the more lifted the longer the interval between the two emissions is. For the system discussed here the comparison between simulation and data has been carried out for the extreme cases, i.e. for a vanishing and infinite time interval between the two emissions, respectively. More sophisticated simulations to describe angular distributions between the emitted fragments were also developed 2 refs.

  4. Correlations between Geomagnetic Disturbances and Field-Aligned Currents during the 22-29 July 2004 Storm Time Interval

    Science.gov (United States)

    Hood, R.; Woodroffe, J. R.; Morley, S.; Aruliah, A. L.

    2017-12-01

    Using the CHAMP fluxgate magnetometer to calculate field-aligned current (FAC) densities and magnetic latitudes, with SuperMAG ground magnetometers analogously providing ground geomagnetic disturbances (GMD) magnetic perturbations and latitudes, we probe FAC locations and strengths as predictors of GMD locations and strengths. We also study the relationships between solar wind drivers and global magnetospheric activity, and both FACs and GMDs using IMF Bz and the Sym-H index. We present an event study of the 22-29 July 2004 storm time interval, which had particularly large GMDs given its storm intensity. We find no correlation between FAC and GMD magnitudes, perhaps due to CHAMP orbit limitations or ground magnetometer coverage. There is, however, a correlation between IMF Bz and nightside GMD magnitudes, supportive of their generation via tail reconnection. IMF Bz is also correlated with dayside FAC and GMD magnetic latitudes, indicating solar wind as an initial driver. The ring current influence increases during the final storm, with improved correlations between the Sym-H index and both FAC magnetic latitudes and GMD magnitudes. Sym-H index correlations may only be valid for higher intensity storms; a statistical analysis of many storms is needed to verify this.

  5. Effect of palady and cup feeding on premature neonates' weight gain and reaching full oral feeding time interval.

    Science.gov (United States)

    Marofi, Maryam; Abedini, Fatemeh; Mohammadizadeh, Majid; Talakoub, Sedigheh

    2016-01-01

    Premature neonates' feeding is of great importance due to its effective role in their growth. These neonates should reach an independent oral nutrition stage before being discharged from the Neonatal Intensive care Unit. Therefore, the researcher decided to conduct a study on the effect of palady and cup feeding on premature neonates' weight gain and their reaching full oral feeding time interval. This is a clinical trial with a quantitative design conducted on 69 premature infants (gestational age between 29 and 32 weeks) who were assigned to cup (n = 34) and palady (n = 35) feeding groups through random allocation. The first feeding was administrated either by cup or palady method in each shift within seven sequential days (total of 21 cup and palady feedings). Then, the rest of feeding was administrated by gavage. Mean hospitalization time (cup = 39.01 and palady = 30.4; P cup = 33.7 and palady = 24.1; P cup group. Mean weight changes of neonates 7 weeks after the intervention compared to those in the beginning of the intervention were significantly more in palady group compared to the cup group (cup = 146.7 and palady = 198.8; P cup group. Subjects' weight gain was also higher in palady group compared to the cup group. Premature neonates with over 30 weeks of gestational age and physiological stability can be fed by palady.

  6. Effect of Remote Back-Up Protection System Failure on the Optimum Routine Test Time Interval of Power System Protection

    Directory of Open Access Journals (Sweden)

    Y Damchi

    2013-12-01

    Full Text Available Appropriate operation of protection system is one of the effective factors to have a desirable reliability in power systems, which vitally needs routine test of protection system. Precise determination of optimum routine test time interval (ORTTI plays a vital role in predicting the maintenance costs of protection system. In the most previous studies, ORTTI has been determined while remote back-up protection system was considered fully reliable. This assumption is not exactly correct since remote back-up protection system may operate incorrectly or fail to operate, the same as the primary protection system. Therefore, in order to determine the ORTTI, an extended Markov model is proposed in this paper considering failure probability for remote back-up protection system. In the proposed Markov model of the protection systems, monitoring facility is taken into account. Moreover, it is assumed that the primary and back-up protection systems are maintained simultaneously. Results show that the effect of remote back-up protection system failures on the reliability indices and optimum routine test intervals of protection system is considerable.

  7. Poststimulation time interval-dependent effects of motor cortex anodal tDCS on reaction-time task performance.

    Science.gov (United States)

    Molero-Chamizo, Andrés; Alameda Bailén, José R; Garrido Béjar, Tamara; García López, Macarena; Jaén Rodríguez, Inmaculada; Gutiérrez Lérida, Carolina; Pérez Panal, Silvia; González Ángel, Gloria; Lemus Corchero, Laura; Ruiz Vega, María J; Nitsche, Michael A; Rivera-Urbina, Guadalupe N

    2018-02-01

    Anodal transcranial direct current stimulation (tDCS) induces long-term potentiation-like plasticity, which is associated with long-lasting effects on different cognitive, emotional, and motor performances. Specifically, tDCS applied over the motor cortex is considered to improve reaction time in simple and complex tasks. The timing of tDCS relative to task performance could determine the efficacy of tDCS to modulate performance. The aim of this study was to compare the effects of a single session of anodal tDCS (1.5 mA, for 15 min) applied over the left primary motor cortex (M1) versus sham stimulation on performance of a go/no-go simple reaction-time task carried out at three different time points after tDCS-namely, 0, 30, or 60 min after stimulation. Performance zero min after anodal tDCS was improved during the whole course of the task. Performance 30 min after anodal tDCS was improved only in the last block of the reaction-time task. Performance 60 min after anodal tDCS was not significantly different throughout the entire task. These findings suggest that the motor cortex excitability changes induced by tDCS can improve motor responses, and these effects critically depend on the time interval between stimulation and task performance.

  8. The use of computed neutron coincidence counting with time interval analysis for the analysis of Fork-measurements on a fresh MOX-LWR fuel assembly under water

    Energy Technology Data Exchange (ETDEWEB)

    Baeten, P.; Bruggeman, M.; Carchon, R

    1998-06-01

    The objective of this study was to investigate the influence of different important parameters on measurement results for various fork-detectors. Computed Neutron Coincidence Counting (CNCC) with Time Interval Analysis (TIA) was used for this study. The performance of the electronics for the different fork-detectors was studied by investigating the deadtime perturbed zone of the Rossi-alpha distribution in TIA. The measurement revealed anomalies in the performance of the electronics of the IAEA BWR and LANL fork-detector. The IAEA PWR fork-detector functioned well and the deadtime parameter was calculated. The optimal setting for the pre delay was investigated and it was found that a pre delay of 10 micro seconds should be considered as an optimum between excluding from analysis data in the deadtime perturbed zone and keeping a high signal-to-noise ratio. For the shift register electronics used with the fork-detectors, a pre delay of only 4.5 micro seconds was used. The study of the pre delay and the deadtime showed that the calculated triples-rate is strongly dependent on these parameters. An accurate determination of the triple-rate in this type of measurements has proven to be quite difficult and requires proper operation of the electronics, a correct pre delay and an accurate deadtime correction formalism. By varying the boron concentration in water, the change of the decay time of the Rossi-alpha distribution was clearly observed. This change is due to the variation of the thermal multiplication. The variation of this decay time with the boron concentration proves that Boehnel's model for fast neutron multiplication is not valid under these measurement conditions and that a model for fast and thermal multiplication should be used in order to obtain unbiased measurement results. CNCC with TIA has proved to be a valuable tool in which parameter settings can be varied a posterori and the optimal setting can be determined for each measurement. Moreover, the

  9. The use of computed neutron coincidence counting with time interval analysis for the analysis of Fork-measurements on a fresh MOX-LWR fuel assembly under water

    International Nuclear Information System (INIS)

    Baeten, P.; Bruggeman, M.; Carchon, R.

    1998-06-01

    The objective of this study was to investigate the influence of different important parameters on measurement results for various fork-detectors. Computed Neutron Coincidence Counting (CNCC) with Time Interval Analysis (TIA) was used for this study. The performance of the electronics for the different fork-detectors was studied by investigating the deadtime perturbed zone of the Rossi-alpha distribution in TIA. The measurement revealed anomalies in the performance of the electronics of the IAEA BWR and LANL fork-detector. The IAEA PWR fork-detector functioned well and the deadtime parameter was calculated. The optimal setting for the pre delay was investigated and it was found that a pre delay of 10 micro seconds should be considered as an optimum between excluding from analysis data in the deadtime perturbed zone and keeping a high signal-to-noise ratio. For the shift register electronics used with the fork-detectors, a pre delay of only 4.5 micro seconds was used. The study of the pre delay and the deadtime showed that the calculated triples-rate is strongly dependent on these parameters. An accurate determination of the triple-rate in this type of measurements has proven to be quite difficult and requires proper operation of the electronics, a correct pre delay and an accurate deadtime correction formalism. By varying the boron concentration in water, the change of the decay time of the Rossi-alpha distribution was clearly observed. This change is due to the variation of the thermal multiplication. The variation of this decay time with the boron concentration proves that Boehnel's model for fast neutron multiplication is not valid under these measurement conditions and that a model for fast and thermal multiplication should be used in order to obtain unbiased measurement results. CNCC with TIA has proved to be a valuable tool in which parameter settings can be varied a posterori and the optimal setting can be determined for each measurement. Moreover, the

  10. Transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in Tianjin, China

    Directory of Open Access Journals (Sweden)

    J Wang

    2014-01-01

    Full Text Available Background: Shigella is one of the common genera of pathogens responsible for bacterial diarrhoea in humans. According to World Health Organisation (WHO, 800,000-1,700,000 patients in China were infected with Shigella spp. in 2000, and Shigella flexneri is the most common serotype (86%. Objectives: We investigated the transfer patterns of integron-associated and antibiotic resistance genes in S. flexneri during different time intervals in the city of Tianjin in the People′s Republic of China. Materials and Methods: The integrase-encoding and variable regions of the integrons of the bacterial strains were amplified by polymerase chain reaction (PCR, followed by gene sequencing. Fifty-six S. flexneri strains, 32 of which were stored in our laboratory and the other 24 were isolated from tertiary hospitals in Tianjin during different time intervals, were tested for their sensitivity to 12 antibiotics by using the Kirby-Bauer antibiotic testing method (K-B method. Results and Conclusion: Of the 32 strains of S. flexneri isolated from 1981 to 1983 and stored in our laboratory, class 1 integron was detected in 28 strains (87.50%, while 27 strains (84.37% harboured an aminoglycoside resistance gene, aadA, in the variable region of their integrons. Class 1 integron was identified in 22 (91.67% of the 24 S. flexneri strains isolated from 2009 to 2010, whereas the variable region and 3′-end amplification were not present in any of the strains. Class 2 integron was not found in the 1981-1983 group (group A of strains; although 19 (79.17% of the 24 strains in the 2009-2010 group (group B possessed class 2 integron, and the variable region of the integron harboured dfrA1 + sat1 + aadA1 genes, which, respectively, mediate antibiotic resistance to trimethoprim, streptothricin and streptomycin. Seventeen strains of the total 56 possessed both class 1 and 2 integrons. Strains belonging to group A were highly resistant to tetracycline, chloramphenicol and a

  11. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Directory of Open Access Journals (Sweden)

    Jean-Louis eHoneine

    2014-10-01

    Full Text Available Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a subtract or integrate sensory inputs, (b move from allocentric to egocentric reference or vice versa, and (c adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1-2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training

  12. Time-interval for integration of stabilizing haptic and visual information in subjects balancing under static and dynamic conditions

    Science.gov (United States)

    Honeine, Jean-Louis; Schieppati, Marco

    2014-01-01

    Maintaining equilibrium is basically a sensorimotor integration task. The central nervous system (CNS) continually and selectively weights and rapidly integrates sensory inputs from multiple sources, and coordinates multiple outputs. The weighting process is based on the availability and accuracy of afferent signals at a given instant, on the time-period required to process each input, and possibly on the plasticity of the relevant pathways. The likelihood that sensory inflow changes while balancing under static or dynamic conditions is high, because subjects can pass from a dark to a well-lit environment or from a tactile-guided stabilization to loss of haptic inflow. This review article presents recent data on the temporal events accompanying sensory transition, on which basic information is fragmentary. The processing time from sensory shift to reaching a new steady state includes the time to (a) subtract or integrate sensory inputs; (b) move from allocentric to egocentric reference or vice versa; and (c) adjust the calibration of motor activity in time and amplitude to the new sensory set. We present examples of processes of integration of posture-stabilizing information, and of the respective sensorimotor time-intervals while allowing or occluding vision or adding or subtracting tactile information. These intervals are short, in the order of 1–2 s for different postural conditions, modalities and deliberate or passive shift. They are just longer for haptic than visual shift, just shorter on withdrawal than on addition of stabilizing input, and on deliberate than unexpected mode. The delays are the shortest (for haptic shift) in blind subjects. Since automatic balance stabilization may be vulnerable to sensory-integration delays and to interference from concurrent cognitive tasks in patients with sensorimotor problems, insight into the processing time for balance control represents a critical step in the design of new balance- and locomotion training devices

  13. Dependency of magnetocardiographically determined fetal cardiac time intervals on gestational age, gender and postnatal biometrics in healthy pregnancies

    Directory of Open Access Journals (Sweden)

    Geue Daniel

    2004-04-01

    Full Text Available Abstract Background Magnetocardiography enables the precise determination of fetal cardiac time intervals (CTI as early as the second trimester of pregnancy. It has been shown that fetal CTI change in course of gestation. The aim of this work was to investigate the dependency of fetal CTI on gestational age, gender and postnatal biometric data in a substantial sample of subjects during normal pregnancy. Methods A total of 230 fetal magnetocardiograms were obtained in 47 healthy fetuses between the 15th and 42nd week of gestation. In each recording, after subtraction of the maternal cardiac artifact and the identification of fetal beats, fetal PQRST courses were signal averaged. On the basis of therein detected wave onsets and ends, the following CTI were determined: P wave, PR interval, PQ interval, QRS complex, ST segment, T wave, QT and QTc interval. Using regression analysis, the dependency of the CTI were examined with respect to gestational age, gender and postnatal biometric data. Results Atrioventricular conduction and ventricular depolarization times could be determined dependably whereas the T wave was often difficult to detect. Linear and nonlinear regression analysis established strong dependency on age for the P wave and QRS complex (r2 = 0.67, p r2 = 0.66, p r2 = 0.21, p r2 = 0.13, p st week onward (p Conclusion We conclude that 1 from approximately the 18th week to term, fetal CTI which quantify depolarization times can be reliably determined using magnetocardiography, 2 the P wave and QRS complex duration show a high dependency on age which to a large part reflects fetal growth and 3 fetal gender plays a role in QRS complex duration in the third trimester. Fetal development is thus in part reflected in the CTI and may be useful in the identification of intrauterine growth retardation.

  14. A Prolonged Time Interval Between Trauma and Prophylactic Radiation Therapy Significantly Increases the Risk of Heterotopic Ossification

    Energy Technology Data Exchange (ETDEWEB)

    Mourad, Waleed F., E-mail: Waleed246@gmail.com [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States); Department of Radiation Oncology, Beth Israel Medical Center, New York, NY (Israel); Packianathan, Satyaseelan [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States); Shourbaji, Rania A. [Department of Epidemiology and Biostatistics, Jackson State University, Jackson, MS (United States); Zhang Zhen; Graves, Mathew [Department of Orthopedic Surgery, University of Mississippi Medical Center, Jackson, MS (United States); Khan, Majid A. [Department of Radiology, University of Mississippi Medical Center, Jackson, MS (United States); Baird, Michael C. [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States); Russell, George [Department of Orthopedic Surgery, University of Mississippi Medical Center, Jackson, MS (United States); Vijayakumar, Srinivasan [Department of Radiation Oncology, University of Mississippi Medical Center, Jackson, MS (United States)

    2012-03-01

    Purpose: To ascertain whether the time from injury to prophylactic radiation therapy (RT) influences the rate of heterotopic ossification (HO) after operative treatment of displaced acetabular fractures. Methods and Materials: This is a single-institution, retrospective analysis of patients referred for RT for the prevention of HO. Between January 2000 and January 2009, 585 patients with displaced acetabular fractures were treated surgically followed by RT for HO prevention. We analyzed the effect of time from injury on prevention of HO by RT. In all patients, 700 cGy was prescribed in a single fraction and delivered within 72 hours postsurgery. The patients were stratified into five groups according to time interval (in days) from the date of their accident to the date of RT: Groups A {<=}3, B {<=}7, C {<=}14, D {<=}21, and E >21days. Results: Of the 585 patients with displaced acetabular fractures treated with RT, (18%) 106 patients developed HO within the irradiated field. The risk of HO after RT increased from 10% for RT delivered {<=}3 days to 92% for treatment delivered >21 days after the initial injury. Wilcoxon test showed a significant correlation between the risk of HO and the length of time from injury to RT (p < 0.0001). Chi-square test and multiple logistic regression analysis showed no significant association between all other factors and the risk of HO (race, gender, cause and type of fracture, surgical approach, or the use of indomethacin). Conclusions: Our data suggest that there is higher incidence and risk of HO if prophylactic RT is significantly delayed after a displaced acetabular fracture. Thus, RT should be administered as early as clinically possible after the trauma. Patients undergoing RT >3 weeks from their displaced acetabular fracture should be informed of the higher risk (>90%) of developing HO despite prophylaxis.

  15. Time intervals from first symptom to treatment of cancer: a cohort study of 2,212 newly diagnosed cancer patients

    Directory of Open Access Journals (Sweden)

    Sokolowski Ineta

    2011-10-01

    Full Text Available Abstract Background Delay in diagnosis of cancer may worsen prognosis. The aim of this study is to explore patient-, general practitioner (GP- and system-related delay in the interval from first cancer symptom to diagnosis and treatment, and to analyse the extent to which delays differ by cancer type. Methods Population-based cohort study conducted in 2004-05 in the County of Aarhus, Denmark (640,000 inhabitants. Data were collected from administrative registries and questionnaires completed by GPs on 2,212 cancer patients newly diagnosed during a 1-year period. Median delay (in days with interquartile interval (IQI was the main outcome measure. Results Median total delay was 98 days (IQI 57-168. Most of the total delay stemmed from patient (median 21 days (7-56 and system delay (median 55 days (32-93. Median GP delay was 0 (0-2 days. Total delay was shortest among patients with ovarian (median 60 days (45-112 and breast cancer (median 65 days (39-106 and longest among patients with prostate (median 130 days (89-254 and bladder cancer (median 134 days (93-181. Conclusion System delay accounted for a substantial part of the total delay experienced by cancer patients. This points to a need for shortening clinical pathways if possible. A long patient delay calls for research into patient awareness of cancer. For all delay components, special focus should be given to the 4th quartile of patients with the longest time intervals and we need research into the quality of the diagnostic work-up process. We found large variations in delay for different types of cancer. Improvements should therefore target both the population at large and the specific needs associated with individual cancer types and their symptoms.

  16. Optimizing 4D cone beam computed tomography acquisition by varying the gantry velocity and projection time interval

    International Nuclear Information System (INIS)

    O’Brien, Ricky T; Cooper, Benjamin J; Keall, Paul J

    2013-01-01

    Four dimensional cone beam computed tomography (4DCBCT) is an emerging clinical image guidance strategy for tumour sites affected by respiratory motion. In current generation 4DCBCT techniques, both the gantry rotation speed and imaging frequency are constant and independent of the patient’s breathing which can lead to projection clustering. We present a mixed integer quadratic programming (MIQP) model for respiratory motion guided-4DCBCT (RMG-4DCBCT) which regulates the gantry velocity and projection time interval, in response to the patient’s respiratory signal, so that a full set of evenly spaced projections can be taken in a number of phase, or displacement, bins during the respiratory cycle. In each respiratory bin, an image can be reconstructed from the projections to give a 4D view of the patient’s anatomy so that the motion of the lungs, and tumour, can be observed during the breathing cycle. A solution to the full MIQP model in a practical amount of time, 10 s, is not possible with the leading commercial MIQP solvers, so a heuristic method is presented. Using parameter settings typically used on current generation 4DCBCT systems (4 min image acquisition, 1200 projections, 10 respiratory bins) and a sinusoidal breathing trace with a 4 s period, we show that the root mean square (RMS) of the angular separation between projections with displacement binning is 2.7° using existing constant gantry speed systems and 0.6° using RMG-4DCBCT. For phase based binning the RMS is 2.7° using constant gantry speed systems and 2.5° using RMG-4DCBCT. The optimization algorithm presented is a critical step on the path to developing a system for RMG-4DCBCT. (paper)

  17. TIARA electrostatic accelerator facility

    International Nuclear Information System (INIS)

    Tajima, Satoshi; Takada, Isao; Mizuhashi, Kiyoshi; Uno, Sadanori; Ohkoshi, Kiyonori; Nakajima, Yoshinori; Saitoh, Yuichi; Ishii, Yasuyuki; Kamiya, Tomihiro

    1996-07-01

    In order to promote the Advanced Radiation Technology Project, Japan Atomic Energy Research Institute constructed TIARA facility composed of four ion accelerators at Takasaki Radiation Chemistry Research Establishment for the period from 1988 to 1993. A 3MV tandem accelerator and an AVF cycrotron were completed in 1991 as the first phase of the construction, and a 3MV single-ended accelerator and a 400kV ion implanter were completed in 1993 as the second phase. Three electrostatic accelerators, the tandem, the single-ended and the implanter, were installed in the Multiple-beam facility of TIARA and have been operated for various experiments with using single, dual and triple beams without any serious trouble. This report describes the constructive works, machine performances, control systems, safety systems and accessory equipments of the electrostatic accelerators. (author)

  18. IAE pulsed electrostatic accelerator

    International Nuclear Information System (INIS)

    Afanas'ev, V.P.; Ganzhelyuk, M.L.; Kozlov, L.D.; Koltypin, E.A.; Molchanov, Yu.D.; Otroshchenko, G.A.; Yan'kov, G.B.

    1976-01-01

    The modernized pulse electrostatic accelerator using the klystron ion grouping and the beam interruption system prior to acceleration is described. The accelerator is modernized in order to improve parameters of a current pulse and to decrease the background in the measurement room. The ion beam of needed dimensions is obtained with the help of a high-frequency source and a beam grouping and deflection system. The general view of the beam grouping and deflection system is shown. The ion beam forming process is considered in detail. The modernized electrostatic accelerator permits to obtain a pulse current with a pulse length of 1.5 ns and an amplitude of 1.5 - 2 μA. With the repetition frequency of 2 MHz, the average target current is about 6 μA

  19. Method of electrostatic filtration

    International Nuclear Information System (INIS)

    Devienne, F.M.

    1975-01-01

    Electrostatic filtration of secondary ions of mass m in a given mass ratio with a primary ion of mass M which has formed the secondary ions by fission is carried out by a method which consists in forming a singly-charged primary ion of the substance having a molecular mass M and extracting the ion at a voltage V 1 with respect to ground. The primary ion crosses a potential barrier V 2 , in producing the dissociation of the ion into at least two fragments of secondary ions and in extracting the fragment ion of mass m at a voltage V 2 . Filtration is carried out in an electrostatic analyzer through which only the ions of energy eV'' are permitted to pass, detecting the ions which have been filtered. The mass m of the ions is such that (M/m) = (V 1 - V 2 )/(V'' - V 2 )

  20. Electrostatic curtain studies

    International Nuclear Information System (INIS)

    Meyer, L.C.

    1992-05-01

    This report presents the results of experiments using electrostatic curtains (ESCS) as a transuranic (TRU) contamination control technique. The TRU contaminants included small (micrometer to sub micrometer) particles of plutonium and americium compounds associated with defense-related waste. Three series of experiments were conducted. The first was with uncontaminated Idaho National Engineering Laboratory (INEL) soil, the second used contaminated soil containing plutonium-239 (from a mixture of Rocky Flats Plant contaminated soil and INEL uncontaminated soil), and the third was uncontaminated INEL soil spiked with plutonium-239. All experiments with contaminated soil were conducted inside a glove box containing a dust generator, low volume cascade impactor (LVCI), electrostatic separator, and electrostatic materials. The data for these experiments consisted of the mass of dust collected on the various material coupons, plates, and filters; radiochemical analysis of selected samples; and photographs, as well as computer printouts giving particle size distributions and dimensions from the scanning electron microscope (SEM). The following results were found: (a) plutonium content (pCi/g) was found to increase with smaller soil particle sizes and (b) the electrostatic field had a stronger influence on smaller particle sizes compared to larger particle sizes. The SEM analysis indicated that the particle size of the tracer Pu239 used in the spiked soil experiments was below the detectable size limit (0.5 μm) of the SEM and, thus, may not be representative of plutonium particles found in defense-related waste. The use of radiochemical analysis indicated that plutonium could be found on separator plates of both polarities, as well as passing through the electric field and collecting on LVCI filters

  1. Electrostatic septum, SPS

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    To minimize losses during slow extraction towards N- and W-Area, electrostatic septa in long straight section 2 and 6 precede the magnetic septa. The 2 electrode plates, visible at the entrance to the septum, establish a vertical electrical field to remove the ions created by the circulating beam in the residual gas. See 7801286 for such a septum in its tank, and 7501201 for a detailed view of the wire suspension. See also 7501120X.

  2. Innovative Electrostatic Adhesion Technologies

    Science.gov (United States)

    Bryan, Tom; Macleod, Todd; Gagliano, Larry; Williams, Scott; McCoy, Brian

    2015-01-01

    Developing specialized Electro-Static grippers (commercially used in Semiconductor Manufacturing and in package handling) will allow gentle and secure Capture, Soft Docking, and Handling of a wide variety of materials and shapes (such as upper-stages, satellites, arrays, and possibly asteroids) without requiring physical features or cavities for a pincher or probe or using harpoons or nets. Combined with new rigid boom mechanisms or small agile chaser vehicles, flexible, high speed Electro-Static Grippers can enable compliant capture of spinning objects starting from a safe stand-off distance. Electroadhesion (EA) can enable lightweight, ultra-low-power, compliant attachment in space by using an electrostatic force to adhere similar and dissimilar surfaces. A typical EA enabled device is composed of compliant space-rated materials, such as copper-clad polyimide encapsulated by polymers. Attachment is induced by strong electrostatic forces between any substrate material, such as an exterior satellite panel and a compliant EA gripper pad surface. When alternate positive and negative charges are induced in adjacent planar electrodes in an EA surface, the electric fields set up opposite charges on the substrate and cause an electrostatic adhesion between the electrodes and the induced charges on the substrate. Since the electrodes and the polymer are compliant and can conform to uneven or rough surfaces, the electrodes can remain intimately close to the entire surface, enabling high clamping pressures. Clamping pressures of more than 3 N/cm2 in shear can be achieved on a variety of substrates with ultra-low holding power consumption (measured values are less than 20 microW/Newton weight held). A single EA surface geometry can be used to clamp both dielectric and conductive substrates, with slightly different physical mechanisms. Furthermore EA clamping requires no normal force be placed on the substrate, as conventional docking requires. Internally funded research and

  3. Electrostatic accelerator dielectrics

    International Nuclear Information System (INIS)

    Cooke, C.M.

    1989-05-01

    High voltage insulation problems in electrostatic accelerators are discussed. The aim of the analysis is to broaden the knowledge, highlight the characteristics of insulation technology and design strategies to improve use. The basic geometry of the insulation in accelerators is considered. A detailed description of each of the insulation regions is provided. The gas gap insulation of the terminal voltage is found to be sensitive to regions of high electric stress. In order to obtain satisfactory performance from solid support insulation, the attention is focused on the electric stress value and distribution. Potential subjects for discussion and further investigations are given

  4. PREFACE: Electrostatics 2015

    Science.gov (United States)

    Matthews, James

    2015-10-01

    Electrostatics 2015, supported by the Institute of Physics, was held in the Sir James Matthews building at Southampton Solent University, UK between 12th and 16th April 2015. Southampton is a historic city on the South Coast of England with a strong military and maritime history. Southampton is home to two Universities: Solent University, which hosted the conference, and the University of Southampton, where much work is undertaken related to electrostatics. 37 oral and 44 poster presentations were accepted for the conference, and 60 papers were submitted and accepted for the proceedings. The Bill Bright Memorial Lecture was delivered this year by Professor Mark Horenstein from Boston University who was, until recently, Editor-in-Chief of the Journal of Electrostatics. He spoke on The contribution of surface potential to diverse problems in electrostatics and his thorough knowledge of the subject of electrostatics was evident in the presentation. The first session was chaired by the Conference Chair, Dr Keith Davies, whose experience in the field showed through his frequent contributions to the discussions throughout the conference. Hazards and Electrostatic Discharge have formed a strong core to Electrostatics conferences for many years, and this conference contained sessions on both Hazards and on ESD, including an invited talk from Dr Jeremy Smallwood on ESD in Industry - Present and Future. Another strong theme to emerge from this year's programme was Non-Thermal Plasmas, which was covered in two sessions. There were two invited talks on this subject: Professor Masaaki Okubo gave a talk on Development of super-clean diesel engine and combustor using nonthermal plasma hybrid after treatment and Dr David Go presented a talk on Atmospheric-pressure ionization processes: New approaches and applications for plasmas in contact with liquids. A new innovation to the conference this year was the opportunity for conference sponsors to present to the delegates a technical

  5. Electrostatically Driven Nanoballoon Actuator.

    Science.gov (United States)

    Barzegar, Hamid Reza; Yan, Aiming; Coh, Sinisa; Gracia-Espino, Eduardo; Dunn, Gabriel; Wågberg, Thomas; Louie, Steven G; Cohen, Marvin L; Zettl, Alex

    2016-11-09

    We demonstrate an inflatable nanoballoon actuator based on geometrical transitions between the inflated (cylindrical) and collapsed (flattened) forms of a carbon nanotube. In situ transmission electron microscopy experiments employing a nanoelectromechanical manipulator show that a collapsed carbon nanotube can be reinflated by electrically charging the nanotube, thus realizing an electrostatically driven nanoballoon actuator. We find that the tube actuator can be reliably cycled with only modest control voltages (few volts) with no apparent wear or fatigue. A complementary theoretical analysis identifies critical parameters for nanotube nanoballoon actuation.

  6. Electrostatics of spherical metallic particles in cylinder electrostatic separators/sizers

    International Nuclear Information System (INIS)

    Lu Hongzhou; Li Jia; Guo Jie; Xu Zhenming

    2006-01-01

    This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/sizers (ESSs). A computational algorithm is employed to depict the cylinder-type electrode arrangements applied in some electrostatic processes generating non-uniform electric fields. The ESS consists of a pair of conducting cylinders. The upper cylinder is energized by HVdc, while the lower one is grounded and mounted horizontally on a revolvable axis. The aim of this paper is to present a new electrode configuration and demonstrate the usefulness of numerical techniques for the evaluation of the particle's motion. A computer program was employed for analysing the behavior of spherical particles in a two-dimensional electrode arrangement that models the actual electric field configuration of cylinder-type electrostatic separators/sizers. The analysis is needed for the development of any new application of this cylinder-type electrode arrangement as an electrostatic separation method. The results reveal that the particle's motion depends on its radius and density and amplitude of the applied voltage. The actual granular mixtures with different specific mass and radius could be separated applying this cylinder-type electrostatic separation method; the lift voltage is an important parameter for separation. With a program for two-dimensional analysis of the electric field, the computational procedure presented in this paper could be employed for any particle shapes

  7. Electrostatically atomised hydrocarbon sprays

    Energy Technology Data Exchange (ETDEWEB)

    Yule, A.J.; Shrimpton, J.S.; Watkins, A.P.; Balachandran, W.; Hu, D. [UMIST, Manchester (United Kingdom). Thermofluids Division, Dept. of Mechanical Engineering

    1995-07-01

    A burner using an electrostatic method to produce and control a fuel spray is investigated for non-burning sprays. The burner has a charge injection nozzle and the liquid flow rate and charge injection rate are varied using hydrocarbon liquids of differing viscosities, surface tensions and electrical conductivities (kerosene, white spirit and diesel oil). Droplet size distributions are measured and it is shown how the dropsize, spray pattern, breakup mechanism and breakup length depend on the above variables, and in particular on the specific charge achieved in the spray. The data are valuable for validating two computer models under development. One predicts the electric field and flow field inside the nozzle as a function of emitter potential, geometry and flow rate. The other predicts the effect of charge on spray dispersion, with a view to optimizing spray combustion. It is shown that electrostatic disruptive forces can be used to atomize oils at flow rates commensurate with practical combustion systems and that the charge injection technique is particularly suitable for highly resistive liquids. Possible limitations requiring further research include the need to control the wide spray angle, which may provide fuel-air mixtures too lean near the nozzle, and the need to design for maximum charge injection rate, which is thought to be limited by corona breakdown in the gas near the nozzle orifice. 30 refs., 15 figs., 1 tab.

  8. Undamped electrostatic plasma waves

    Energy Technology Data Exchange (ETDEWEB)

    Valentini, F.; Perrone, D.; Veltri, P. [Dipartimento di Fisica and CNISM, Universita della Calabria, 87036 Rende (CS) (Italy); Califano, F.; Pegoraro, F. [Dipartimento di Fisica and CNISM, Universita di Pisa, 56127 Pisa (Italy); Morrison, P. J. [Institute for Fusion Studies and Department of Physics, University of Texas at Austin, Austin, Texas 78712-1060 (United States); O' Neil, T. M. [Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)

    2012-09-15

    Electrostatic waves in a collision-free unmagnetized plasma of electrons with fixed ions are investigated for electron equilibrium velocity distribution functions that deviate slightly from Maxwellian. Of interest are undamped waves that are the small amplitude limit of nonlinear excitations, such as electron acoustic waves (EAWs). A deviation consisting of a small plateau, a region with zero velocity derivative over a width that is a very small fraction of the electron thermal speed, is shown to give rise to new undamped modes, which here are named corner modes. The presence of the plateau turns off Landau damping and allows oscillations with phase speeds within the plateau. These undamped waves are obtained in a wide region of the (k,{omega}{sub R}) plane ({omega}{sub R} being the real part of the wave frequency and k the wavenumber), away from the well-known 'thumb curve' for Langmuir waves and EAWs based on the Maxwellian. Results of nonlinear Vlasov-Poisson simulations that corroborate the existence of these modes are described. It is also shown that deviations caused by fattening the tail of the distribution shift roots off of the thumb curve toward lower k-values and chopping the tail shifts them toward higher k-values. In addition, a rule of thumb is obtained for assessing how the existence of a plateau shifts roots off of the thumb curve. Suggestions are made for interpreting experimental observations of electrostatic waves, such as recent ones in nonneutral plasmas.

  9. Undamped electrostatic plasma waves

    International Nuclear Information System (INIS)

    Valentini, F.; Perrone, D.; Veltri, P.; Califano, F.; Pegoraro, F.; Morrison, P. J.; O'Neil, T. M.

    2012-01-01

    Electrostatic waves in a collision-free unmagnetized plasma of electrons with fixed ions are investigated for electron equilibrium velocity distribution functions that deviate slightly from Maxwellian. Of interest are undamped waves that are the small amplitude limit of nonlinear excitations, such as electron acoustic waves (EAWs). A deviation consisting of a small plateau, a region with zero velocity derivative over a width that is a very small fraction of the electron thermal speed, is shown to give rise to new undamped modes, which here are named corner modes. The presence of the plateau turns off Landau damping and allows oscillations with phase speeds within the plateau. These undamped waves are obtained in a wide region of the (k,ω R ) plane (ω R being the real part of the wave frequency and k the wavenumber), away from the well-known “thumb curve” for Langmuir waves and EAWs based on the Maxwellian. Results of nonlinear Vlasov-Poisson simulations that corroborate the existence of these modes are described. It is also shown that deviations caused by fattening the tail of the distribution shift roots off of the thumb curve toward lower k-values and chopping the tail shifts them toward higher k-values. In addition, a rule of thumb is obtained for assessing how the existence of a plateau shifts roots off of the thumb curve. Suggestions are made for interpreting experimental observations of electrostatic waves, such as recent ones in nonneutral plasmas.

  10. Electrostatic Plasma Accelerator (EPA)

    Science.gov (United States)

    Brophy, John R.; Aston, Graeme

    1995-01-01

    The application of electric propulsion to communications satellites, however, has been limited to the use of hydrazine thrusters with electric heaters for thrust and specific impulse augmentation. These electrothermal thrusters operate at specific impulse levels of approximately 300 s with heater powers of about 500 W. Low power arcjets (1-3 kW) are currently being investigated as a way to increase specific impulse levels to approximately 500 s. Ion propulsion systems can easily produce specific impulses of 3000 s or greater, but have yet to be applied to communications satellites. The reasons most often given for not using ion propulsion systems are their high level of overall complexity, low thrust with long burn times, and the difficulty of integrating the propulsion system into existing commercial spacecraft busses. The Electrostatic Plasma Accelerator (EPA) is a thruster concept which promises specific impulse levels between low power arcjets and those of the ion engine while retaining the relative simplicity of the arcjet. The EPA thruster produces thrust through the electrostatic acceleration of a moderately dense plasma. No accelerating electrodes are used and the specific impulse is a direct function of the applied discharge voltage and the propellant atomic mass.

  11. A novel electrostatic precipitator

    International Nuclear Information System (INIS)

    Tang, Minkang; Wang, Liqian; Lin, Zhigui

    2013-01-01

    ESP (Electrostatic Precipitation) has been widely used in the mining, building materials, metallurgy and power industries. Dust particles or other harmful particles from the airstream can be precipitated by ESP with great collecting efficiency. Because of its' large size, high cost and energy consumption, the scope of application of ESP has been limited to a certain extent. By means of the theory of electrostatics and fluid dynamics, a corona assembly with a self-cleaning function and a threshold voltage automatic tracking technology has been developed and used in ESP. It is indicated that compared with conventional ESP, the electric field length has been reduced to 1/10 of the original, the current density on the collecting electrode increased 3-5 times at the maximum, the approach speed of dust particles in the electric field towards the collecting electrode is 4 times that in conventional ESP and the electric field wind speed may be enhanced by 2-3 times the original. Under the premise of ESP having a high efficiency of dust removal, equipment volume may be actually reduced to 1/5 to 1/10 of the original volume and energy consumption may be reduced by more than 50%.

  12. The effect of chorionicity and twin-to-twin delivery time interval on short-term outcome of the second twin

    DEFF Research Database (Denmark)

    Hjortø, Sofie; Nickelsen, Carsten; Petersen, Janne

    2013-01-01

    Abstract Objectives: To investigate the effect of chorionicity and twin-to-twin delivery time interval on short-term outcome in the second twin. Additionally, to investigate predictors of adverse outcome in both twins. Methods: Data included vaginally delivered twins (≥ 36 weeks) from Copenhagen ...

  13. Self-produced Time Intervals Are Perceived as More Variable and/or Shorter Depending on Temporal Context in Subsecond and Suprasecond Ranges

    Directory of Open Access Journals (Sweden)

    Keita eMitani

    2016-06-01

    Full Text Available The processing of time intervals is fundamental for sensorimotor and cognitive functions. Perceptual and motor timing are often performed concurrently (e.g., playing a musical instrument. Although previous studies have shown the influence of body movements on time perception, how we perceive self-produced time intervals has remained unclear. Furthermore, it has been suggested that the timing mechanisms are distinct for the sub- and suprasecond ranges. Here, we compared perceptual performances for self-produced and passively presented time intervals in random contexts (i.e., multiple target intervals presented in a session across the sub- and suprasecond ranges (Experiment 1 and within the sub- (Experiment 2 and suprasecond (Experiment 3 ranges, and in a constant context (i.e., a single target interval presented in a session in the sub- and suprasecond ranges (Experiment 4. We show that self-produced time intervals were perceived as shorter and more variable across the sub- and suprasecond ranges and within the suprasecond range but not within the subsecond range in a random context. In a constant context, the self-produced time intervals were perceived as more variable in the suprasecond range but not in the subsecond range. The impairing effects indicate that motor timing interferes with perceptual timing. The dependence of impairment on temporal contexts suggests multiple timing mechanisms for the subsecond and suprasecond ranges. In addition, violation of the scalar property (i.e., a constant variability to target interval ratio was observed between the sub- and suprasecond ranges. The violation was clearer for motor timing than for perceptual timing. This suggests that the multiple timing mechanisms for the sub- and suprasecond ranges overlap more for perception than for motor. Moreover, the central tendency effect (i.e., where shorter base intervals are overestimated and longer base intervals are underestimated disappeared with subsecond

  14. Electrostatic energy of KHF2

    NARCIS (Netherlands)

    Gool, W. van; Bruinink, J.; Bottelberghs, P.H.

    1972-01-01

    Electrostatic lattice energies are calculated in KHF2. Fractional charges occurring in the complex anions are treated with a general procedure and the results are compared to a specialized approach reported earlier. Interstitial potentials are calculated to obtain the electrostatic field through

  15. Electrostatic ion acoustic waves

    International Nuclear Information System (INIS)

    Hasegawa, A.

    1983-01-01

    In this paper, certain aspects of plasma physics are illustrated through a study of electrostatic ion acoustic waves. The paper consists of three Sections. Section II deals with linear properties of the ion acoustic wave including derivation of the dispersions relation with the effect of Landau damping and of an ambient magnetic field. The section also introduces the excitation processes of the ion acoustic wave due to an electron drift or to a stimulated Brillouin scattering. The nonlinear properties are introduced in Section III and IV. In Section III, incoherent nonlinear effects such as quasilinear and mode-coupling saturations of the instability are discussed. The coherent nonlinear effects such as the generation of ion acoustic solitons, shocks and weak double layers are presented in Section IV. (Auth.)

  16. Irradiation and electrostatic separator

    International Nuclear Information System (INIS)

    Schultz, M.A.

    1976-01-01

    An apparatus for collecting pollutants in which a passageway is formed to define a path for industrial gases passing therethrough is described. A plurality of isotope sources extend along at least a portion of the path followed by the industrial gases to provide a continuing irradiation zone for pollutants in the gases. Collecting electrode plates are associated with such an irradiation zone to efficiently collect particulates as a result of an electrostatic field established between such plates, particularly very small particulates. The series of isotope sources are extended for a length sufficient to attain material improvement in the efficiency of collecting the pollutants. Such an effective length is established along a substantially unidirectional path of the gases, or preferably a reversing path in a folded conduit assembly to attain further efficiency by allowing more compact apparatus structures

  17. Combined computational and biochemical study reveals the importance of electrostatic interactions between the "pH sensor" and the cation binding site of the sodium/proton antiporter NhaA of Escherichia coli.

    Science.gov (United States)

    Olkhova, Elena; Kozachkov, Lena; Padan, Etana; Michel, Hartmut

    2009-08-15

    Sodium proton antiporters are essential enzymes that catalyze the exchange of sodium ions for protons across biological membranes. The crystal structure of NhaA has provided a basis to explore the mechanism of ion exchange and its unique regulation by pH. Here, the mechanism of the pH activation of the antiporter is investigated through functional and computational studies of several variants with mutations in the ion-binding site (D163, D164). The most significant difference found computationally between the wild type antiporter and the active site variants, D163E and D164N, are low pK(a) values of Glu78 making them insensitive to pH. Although in the variant D163N the pK(a) of Glu78 is comparable to the physiological one, this variant cannot demonstrate the long-range electrostatic effect of Glu78 on the pH-dependent structural reorganization of trans-membrane helix X and, hence, is proposed to be inactive. In marked contrast, variant D164E remains sensitive to pH and can be activated by alkaline pH shift. Remarkably, as expected computationally and discovered here biochemically, D164E is viable and active in Na(+)/H(+) exchange albeit with increased apparent K(M). Our results unravel the unique electrostatic network of NhaA that connect the coupled clusters of the "pH sensor" with the binding site, which is crucial for pH activation of NhaA. 2009 Wiley-Liss, Inc.

  18. Lunar electrostatic effects and protection

    International Nuclear Information System (INIS)

    Sun, Yongwei; Yuan, Qingyun; Xiong, Jiuliang

    2013-01-01

    The space environment and features on the moon surface are factors in strong electrostatic electrification. Static electricity will be produced in upon friction between lunar soil and detectors or astronauts on the lunar surface. Lunar electrostatic environment effects from lunar exploration equipment are very harmful. Lunar dust with electrostatic charge may enter the equipment or even cover the instruments. It can affect the normal performance of moon detectors. Owing to the huge environmental differences between the moon and the earth, the electrostatic protection technology on the earth can not be applied. In this paper, we review the electrostatic characteristics of lunar dust, its effects on aerospace equipment and moon static elimination technologies. It was concluded that the effect of charged lunar dust on detectors and astronauts should be completely researched as soon as possible.

  19. Electrostatic control of the dynamics of lipid bilayer self-spreading using a nanogap gate

    International Nuclear Information System (INIS)

    Kashimura, Y; Sumitomo, K; Furukawa, K

    2014-01-01

    The electrostatic control of lipid bilayer self-spreading was investigated using a device equipped with a nanogap gate. A series of mixtures containing negatively charged and uncharged lipids were employed to tune the charge of a membrane. We found that when a voltage is applied on a lipid bilayer passing through a nanogap, the effect of a voltage application on the dynamics depended largely on the charge of the membrane. For rich charged lipid compositions (>10 mol%), the self-spreading was electrostatically controlled applying an electric field to the nanogap. The origin of the behaviour is the electrostatic trapping of charged lipids. The trapped lipids close the nanogap gate, thus preventing any lipid molecules from passing through it. For poor charged lipid compositions (∼1 mol%), no electrostatic trapping occurred even when a lipid bilayer reached the nanogap. Instead, we observed the cessation of self-spreading after a sufficient post-passage time interval, indicating that the translational flow force of self-spreading overcomes the trapping force. For uncharged lipid compositions, there was no electrostatic trapping throughout the measurement. The results suggest that the lipid charge plays a vital role in the electrostatic control mechanism and allow us to control lipid bilayer formation both spatially and temporally. (paper)

  20. Electrostatic fluctuations in soap films

    International Nuclear Information System (INIS)

    Dean, D.S.; Horgan, R.R.

    2002-01-01

    A field theory to describe electrostatic interactions in soap films, described by electric multilayers with a generalized thermodynamic surface-charging mechanism, is studied. In the limit where the electrostatic interactions are weak, this theory is exactly soluble. The theory incorporates in a consistent way, the surface-charging mechanism and the fluctuations in the electrostatic field that correspond to the zero-frequency component of the van der Waals force. It is shown that these terms lead to a Casimir-like attraction that can be sufficiently large to explain the transition between the common black film to a Newton black film

  1. Electrical operation of electrostatic precipitators

    CERN Document Server

    Parker, Ken

    2003-01-01

    The electrostatic precipitator remains on of the most cost effective means of controlling the emission of particulates from most industrial processes. This book will be of interest to both users and suppliers of electrostatic precipitators as well as advanced students on environmental based courses. The author identifies the physical and engineering basis for the development of electrical equipment for electrostatic precipitators and thoroughly explores the technological factors which optimize the efficiency of the precipitator and hence minimize emissions, as well as future developments in th

  2. Proceedings of Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting (23rd) held in Pasadena, California on December 3-5, 1991

    Science.gov (United States)

    1991-12-05

    Between Two Western European Time Laboratories and VNIIFTRI ............. 341 P Daly, University of Leeds, N.B. Koshelyaevsky, VNIIFTRI , and W Lewandowski...equipped with GPS time receivers and contributing to TAI. The last GPS antenna position determined by the BIPM is installed near Moscow in the VNIIFTRI : it...Leeds and VNIIFTRI ", accepted in Proc. 23rd Annual Precise Time and Time Interval (PTTI) Applications and Planning Meeting, 1991. 15. W. Lewandowski and

  3. Explosion safety in industrial electrostatics

    Science.gov (United States)

    Szabó, S. V.; Kiss, I.; Berta, I.

    2011-01-01

    Complicated industrial systems are often endangered by electrostatic hazards, both from atmospheric (lightning phenomenon, primary and secondary lightning protection) and industrial (technological problems caused by static charging and fire and explosion hazards.) According to the classical approach protective methods have to be used in order to remove electrostatic charging and to avoid damages, however no attempt to compute the risk before and after applying the protective method is made, relying instead on well-educated and practiced expertise. The Budapest School of Electrostatics - in close cooperation with industrial partners - develops new suitable solutions for probability based decision support (Static Control Up-to-date Technology, SCOUT) using soft computing methods. This new approach can be used to assess and audit existing systems and - using the predictive power of the models - to design and plan activities in industrial electrostatics.

  4. Ion sources for electrostatic accelerators

    International Nuclear Information System (INIS)

    Hellborg, R.

    1998-01-01

    Maybe the most important part of an electrostatic accelerator system, and also often the most tricky part is the ion source. There has been a rapid growth in activity in ion-source research and development during the last two to three decades. Some of these developments have also been of benefit to electrostatic accelerator users. In this report some of the different types of ion sources used in electrostatic accelerators are described. The list is not complete but more an overview of some of the more commonly used sources. The description is divided into two groups; positive ion sources for single stage electrostatic accelerators and negative ion sources for two stages (i.e. tandem) accelerators

  5. Computational Methods for Biomolecular Electrostatics

    Science.gov (United States)

    Dong, Feng; Olsen, Brett; Baker, Nathan A.

    2008-01-01

    An understanding of intermolecular interactions is essential for insight into how cells develop, operate, communicate and control their activities. Such interactions include several components: contributions from linear, angular, and torsional forces in covalent bonds, van der Waals forces, as well as electrostatics. Among the various components of molecular interactions, electrostatics are of special importance because of their long range and their influence on polar or charged molecules, including water, aqueous ions, and amino or nucleic acids, which are some of the primary components of living systems. Electrostatics, therefore, play important roles in determining the structure, motion and function of a wide range of biological molecules. This chapter presents a brief overview of electrostatic interactions in cellular systems with a particular focus on how computational tools can be used to investigate these types of interactions. PMID:17964951

  6. Electrostatic beam-position monitor

    CERN Multimedia

    CERN PhotoLab

    1969-01-01

    Electrostatic beam-position monitor installed in its final location (bake-out cover removed). The ISR will contain about 110 of these monitors. Their accuracy is better than 1 mm, their band width about 1 MHz.

  7. Electrostatic Phenomena on Planetary Surfaces

    Science.gov (United States)

    Calle, Carlos I.

    2017-02-01

    The diverse planetary environments in the solar system react in somewhat different ways to the encompassing influence of the Sun. These different interactions define the electrostatic phenomena that take place on and near planetary surfaces. The desire to understand the electrostatic environments of planetary surfaces goes beyond scientific inquiry. These environments have enormous implications for both human and robotic exploration of the solar system. This book describes in some detail what is known about the electrostatic environment of the solar system from early and current experiments on Earth as well as what is being learned from the instrumentation on the space exploration missions (NASA, European Space Agency, and the Japanese Space Agency) of the last few decades. It begins with a brief review of the basic principles of electrostatics.

  8. Holes in magneto electrostatic traps

    International Nuclear Information System (INIS)

    Jones, R.

    1996-01-01

    We observe that in magneto electrostatic confinement (MEC) devices the magnetic surfaces are not always equipotentials. The lack of symmetry in the equipotential surfaces can result in holes in MEC plasma traps. (author)

  9. Noncontact measurement of electrostatic fields: Verification of modeled potentials within ion mobility spectrometer drift tube designs

    International Nuclear Information System (INIS)

    Scott, Jill R.; Tremblay, Paul L.

    2007-01-01

    The heart of an ion mobility spectrometer is the drift region where ion separation occurs. While the electrostatic potentials within a drift tube design can be modeled, no method for independently validating the electrostatic field has previously been reported. Two basic drift tube designs were modeled using SIMION 7.0 to reveal the expected electrostatic fields: (1) A traditional alternating set of electrodes and insulators and (2) a truly linear drift tube. One version of the alternating electrode/insulator drift tube and two versions of linear drift tubes were then fabricated. The stacked alternating electrodes/insulators were connected through a resistor network to generate the electrostatic gradient in the drift tube. The two linear drift tube designs consisted of two types of resistive drift tubes with one tube consisting of a resistive coating within an insulating tube and the other tube composed of resistive ferrites. The electrostatic fields within each type of drift tube were then evaluated by a noncontact method using a Kelvin-Zisman type electrostatic voltmeter and probe (results for alternative measurement methods provided in supplementary material). The experimental results were then compared with the electrostatic fields predicted by SIMION. Both the modeling and experimental measurements reveal that the electrostatic fields within a stacked ion mobility spectrometer drift tube are only pseudo-linear, while the electrostatic fields within a resistive drift tube approach perfect linearity

  10. Effect of time interval between capecitabine intake and radiotherapy on local recurrence-free survival in preoperative chemoradiation for locally advanced rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Joo; Kim, Jong Hoon; Yu, Chang Sik; Kim, Tae Won; Jang, Se Jin; Choi, Eun Kyung; Kim, Jin Cheon [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of); Choi, Won Sik [University of Ulsan College of Medicine, Gangneung (Korea, Republic of)

    2017-06-15

    The concentration of capecitabine peaks at 1–2 hours after administration. We therefore assumed that proper timing of capecitabine administration and radiotherapy would maximize radiosensitization and influence survival among patients with locally advanced rectal cancer. We retrospectively reviewed 223 patients with locally advanced rectal cancer who underwent preoperative chemoradiation, followed by surgery from January 2002 to May 2006. All patients underwent pelvic radiotherapy (50 Gy/25 fractions) and received capecitabine twice daily at 12-hour intervals (1,650 mg/m2/day). Patients were divided into two groups according to the time interval between capecitabine intake and radiotherapy. Patients who took capecitabine 1 hour before radiotherapy were classified as Group A (n = 109); all others were classified as Group B (n = 114). The median follow-up period was 72 months (range, 7 to 149 months). Although Group A had a significantly higher rate of good responses (44% vs. 25%; p = 0.005), the 5-year local recurrence-free survival rates of 93% in Group A and 97% in Group B did not differ significantly (p = 0.519). The 5-year disease-free survival and overall survival rates were also comparable between the groups. Despite the better pathological response in Group A, the time interval between capecitabine and radiotherapy administration did not have a significant effect on survivals. Further evaluations are needed to clarify the interaction of these treatment modalities.

  11. The in vitro antibacterial effect of iodine-potassium iodide and calcium hydroxide in infected dentinal tubules at different time intervals.

    Science.gov (United States)

    Lin, Shaul; Kfir, Anda; Laviv, Amir; Sela, Galit; Fuss, Zvi

    2009-03-01

    The aim of this study was to evaluate the antibacterial effect of iodine-potassium iodide (IKI) and calcium hydroxide (CH) on dentinal tubules infected with Enterococcus faecalis (E. faecalis) at different time intervals. Hollow cylinders of bovine root dentin (n=45) were infected and divided into three equal groups filled with either IKI or CH and a positive control. After placing each medicament in the infected cylinders for time periods of 10 minutes, 48 hours and 7 days, microbiological samples were analyzed. At the end of each period, four 100 microm thick inner dentin layers (400 microm thick from each specimen) were removed using dental burs of increasing diameters. Dentin powder was cultured on agar plates to quantitatively assess their infection, expressed in colony forming units (cfu). In all layers of the positive control group, heavy bacterial infection was observed. After 10 minutes, IKI reduced the amount of viable bacteria more efficiently than CH, whereas at later time intervals CH showed the best results. For short periods of exposure, IKI has a more efficient antibacterial effect in the dentinal tubules than CH but CH performs better after longer durations of exposure. This research indicates the use of IKI is a better choice for disinfecting the root canal than CH if only a short duration of exposure is used because of its more efficient antibacterial effect. However, if a longer exposure time is used, then CH is a better choice because of its better disinfecting effect over time.

  12. Effect of time intervals between irradiation and chemotherapeutic agents on the normal tissue damage. Comparison between in vivo and in vitro experiments

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hisao; Nakayama, Toshitake; Hashimoto, Shozo (Keio Univ., Tokyo (Japan). School of Medicine)

    1989-05-01

    Experiments have been carried out to determine the effect on the cell survivals at different time intervals between irradiation and chemotherapeutic agents (BLM, cisDDP, ADM and ACNU) in either the in vivo or the in vitro system. The intestinal epithelial assay was applied on the in vivo system. The clonogenic cell survivals of V/sub 79/ cells, both in the proliferative and the plateau phases, were determined in the in vitro system. The V/sub 79/ cells in the plateau phase were more sensitive to BLM, cisDDP and ACNU than those in the proliferative phase, however, the result was reverse with ADM. When BLM, cisDDP or ACNU was combined with irradiation at different time intervals, the response of the plateau phase V/sub 79/ cells to combination therapies were very similar to those of the intestinal epithelial cells. On the other hand, V/sub 79/ cells in the proliferative phase, which were treated with ADM and irradiation, showed the similar response as the intestinal cells. These results suggest that studies of chemo-radiotherapy with cultured cells which are sensitive to chemotherapeutic agents might be suitable to expect the in vivo damage of the normal tissue. (author).

  13. Surface electrostatics: theory and computations

    KAUST Repository

    Chatzigeorgiou, G.

    2014-02-05

    The objective of this work is to study the electrostatic response of materials accounting for boundary surfaces with their own (electrostatic) constitutive behaviour. The electric response of materials with (electrostatic) energetic boundary surfaces (surfaces that possess material properties and constitutive structures different from those of the bulk) is formulated in a consistent manner using a variational framework. The forces and moments that appear due to bulk and surface electric fields are also expressed in a consistent manner. The theory is accompanied by numerical examples on porous materials using the finite-element method, where the influence of the surface electric permittivity on the electric displacement, the polarization stress and the Maxwell stress is examined.

  14. Inertial Electrostatic Confinement (IEC) devices

    International Nuclear Information System (INIS)

    Nebel, R.A.; Turner, L.; Tiouririne, T.N.; Barnes, D.C.; Nystrom, W.D.; Bussard, R.W.; Miley, G.H.; Javedani, J.; Yamamoto, Y.

    1994-01-01

    Inertial Electrostatic Confinement (IEC) is one of the earliest plasma confinement concepts, having first been suggested by P. T. Farnsworth in the 1950s. The concept involves a simple apparatus of concentric spherical electrostatic grids or a combination of grids and magnetic fields. An electrostatic structure is formed from the confluence of electron or ion beams. Gridded IEC systems have demonstrated neutron yields as high as 2 * 10 10 neutrons/sec. These systems have considerable potential as small, inexpensive, portable neutron sources for assaying applications. Neutron tomography is also a potential application. Atomic physics effects strongly influence the performance of all of these systems. Important atomic effects include elastic scattering, ionization, excitation, and charge exchange. This paper discusses how an IEC system is influenced by these effects and how to design around them. Theoretical modeling and experimental results are presented

  15. Charge sniffer for electrostatics demonstrations

    Science.gov (United States)

    Dinca, Mihai P.

    2011-02-01

    An electronic electroscope with a special design for demonstrations and experiments on static electricity is described. It operates as an electric charge sniffer by detecting slightly charged objects when they are brought to the front of its sensing electrode. The sniffer has the advantage of combining high directional sensitivity with a logarithmic bar display. It allows for the identification of electric charge polarity during charge separation by friction, peeling, electrostatic induction, batteries, or secondary coils of power transformers. Other experiments in electrostatics, such as observing the electric field of an oscillating dipole and the distance dependence of the electric field generated by simple charge configurations, are also described.

  16. The diagnostic accuracy of TCD for intracranial arterial stenosis/occlusion in patients with acute ischemic stroke: the importance of time interval between detection of TCD and CTA.

    Science.gov (United States)

    Guan, Jingxia; Zhou, Qin; Ouyang, Huangqing; Zhang, Shaofeng; Lu, Zuneng

    2013-11-01

    To evaluate prospectively the diagnostic accuracy of transcranial doppler (TCD) as an additional screening tool for intracranial arterial steno-occlusive disease against computed tomography angiography (CTA) in patients with acute ischemic stroke (AIS) if both are performed in a short time interval. Between July 2011 and May 2012, 128 patients who were hospitalized within 24 hours of symptom onset and fulfilled the criteria for the clinical diagnosis of AIS were enrolled. Bedside detection of TCD was accomplished immediately after admission. High-resolution brain CTA was performed within 3 hours after the completion of TCD and the images were interpreted by a neuroradiologist blinded to TCD findings. The accuracy parameters of TCD against CTA were calculated after computation of true-positive, false-positive, true negative, and false-negative values. Among the 128 patients, there were 68 males and 60 females, aged 61.4 ± 17.5 years. The mean time interval between the detection of TCD and CTA was 89.7 (77.8) minutes. In 65% of patients, both examinations were performed with less than a half-hour interval between them. The diagnostic accuracy of TCD for different arteries showed slight distinction. Transcranial doppler demonstrated the most accurate diagnosis for middle cerebral artery (MCA), where TCD showed 35 true-positive, 0 false-negative, 1 false-positive, and 92 true-negative studies compared with CTA. Furthermore, elevated MCA velocities on TCD correlated well with the severity of intracranial stenosis detected on CTA. Vertebral artery (VA) is one of the arteries with the lowest sensitivity for TCD diagnosis (sensitivity 63.4%, specificity 96.5%, positive predictive value (PPV) 89.6%, negative predictive value (NPV) 84.8%, and accuracy 85.9%). In 20 cases (15.6%), TCD showed findings complementary to CTA (real-time embolization, collateral flow patterns, and steal phenomenon). Transcranial doppler shows high diagnostic accuracy against CTA if both are

  17. Continuous electrodeionization through electrostatic shielding

    International Nuclear Information System (INIS)

    Dermentzis, Konstantinos

    2008-01-01

    We report a new continuous electrodeionization cell with electrostatically shielded concentrate compartments or electrochemical Faraday cages formed by porous electronically and ionically conductive media, instead of permselective ion exchange membranes. Due to local elimination of the applied electric field within the compartments, they electrostatically retain the incoming ions and act as 'electrostatic ion pumps' or 'ion traps' and therefore concentrate compartments. The porous media are chemically and thermally stable. Electrodeionization or electrodialysis cells containing such concentrate compartments in place of ion exchange membranes can be used to regenerate ion exchange resins and produce deionized water, to purify industrial effluents and desalinate brackish or seawater. The cells can work by polarity reversal without any negative impact to the deionization process. Because the electronically and ionically active media constituting the electrostatically shielded concentrate compartments are not permselective and coions are not repelled but can be swept by the migrating counterions, the cells are not affected by the known membrane associated limitations, such as concentration polarization or scaling and show an increased current efficiency

  18. Linac boosters for electrostatic machines

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; Brookhaven National Lab., Upton, NY

    1990-01-01

    A survey of linacs which are used as boosters to electrostatic accelerators is presented. Machines both operating and under construction, copper and superconducting, are reviewed. The review includes data on the accelerating structures, performance, rf and control, beam optics, budget, vacuum and cryogenics. (orig.)

  19. MK-801 and memantine act differently on short-term memory tested with different time-intervals in the Morris water maze test.

    Science.gov (United States)

    Duda, Weronika; Wesierska, Malgorzata; Ostaszewski, Pawel; Vales, Karel; Nekovarova, Tereza; Stuchlik, Ales

    2016-09-15

    N-methyl-d-aspartate receptors (NMDARs) play a crucial role in spatial memory formation. In neuropharmacological studies their functioning strongly depends on testing conditions and the dosage of NMDAR antagonists. The aim of this study was to assess the immediate effects of NMDAR block by (+)MK-801 or memantine on short-term allothetic memory. Memory was tested in a working memory version of the Morris water maze test. In our version of the test, rats underwent one day of training with 8 trials, and then three experimental days when rats were injected intraperitoneally with low- 5 (MeL), high - 20 (MeH) mg/kg memantine, 0.1mg/kg MK-801 or 1ml/kg saline (SAL) 30min before testing, for three consecutive days. On each experimental day there was just one acquisition and one test trial, with an inter-trial interval of 5 or 15min. During training the hidden platform was relocated after each trial and during the experiment after each day. The follow-up effect was assessed on day 9. Intact rats improved their spatial memory across the one training day. With a 5min interval MeH rats had longer latency then all rats during retrieval. With a 15min interval the MeH rats presented worse working memory measured as retrieval minus acquisition trial for path than SAL and MeL and for latency than MeL rats. MK-801 rats had longer latency than SAL during retrieval. Thus, the high dose of memantine, contrary to low dose of MK-801 disrupts short-term memory independent on the time interval between acquisition and retrieval. This shows that short-term memory tested in a working memory version of water maze is sensitive to several parameters: i.e., NMDA receptor antagonist type, dosage and the time interval between learning and testing. Copyright © 2016. Published by Elsevier B.V.

  20. Usability of a new multiple high-speed pulse time data registration, processing and real-time display system for pulse time interval analysis

    International Nuclear Information System (INIS)

    Yawata, Takashi; Sakaue, Hisanobu; Hashimoto, Tetsuo; Itou, Shigeki

    2006-01-01

    A new high-speed multiple pulse time data registration, processing and real-time display system for time interval analysis (TIA) was developed for counting either β-α or α-α correlated decay-events. The TIA method has been so far limited to selective extraction of successive α-α decay events within the milli-second time scale owing to the use of original electronic hardware. In the present pulse-processing system, three different high-speed α/β(γ) pulses could be fed quickly to original 32 bit PCI board (ZN-HTS2) within 1 μs. This original PCI board is consisting of a timing-control IC (HTS-A) and 28 bit counting IC (HTS-B). All channel and pulse time data were stored to FIFO RAM, followed to transfer into temporary CPU RAM (32 MB) by DMA. Both data registration (into main RAM (200 MB)) and calculation of pulse time intervals together with real-time TIA-distribution display simultaneously processed using two sophisticate softwares. The present system has proven to succeed for the real-time display of TIA distribution spectrum even when 1.6x10 5 cps pulses from pulse generator were given to the system. By using this new system combined with liquid scintillation counting (LSC) apparatus, both a natural micro-second order β-α correlated decay-events and a milli-second order α-α correlated decay-event could be selectively extracted from the mixture of natural radionuclides. (author)

  1. An Intervention to Reduce the Time Interval Between Hospital Entry and Emergency Coronary Angiography in Patients with ST-Elevation Myocardial Infarction.

    Science.gov (United States)

    Karkabi, Basheer; Jaffe, Ronen; Halon, David A; Merdler, Amnon; Khader, Nader; Rubinshtein, Ronen; Goldstein, Jacob; Zafrir, Barak; Zissman, Keren; Ben-Dov, Nissan; Gabrielly, Michael; Fuks, Alex; Shiran, Avinoam; Adawi, Salim; Hellman, Yaron; Shahla, Johny; Halabi, Salim; Flugelman, Moshe Y; Cohen, Shai; Bergman, Irina; Kassem, Sameer; Shapira, Chen

    2017-09-01

    Outcomes of patients with acute ST-elevation myocardial infarction (STEMI) are strongly correlated to the time interval from hospital entry to primary percutaneous coronary intervention (PPCI). Current guidelines recommend a door to balloon time of < 90 minutes. To reduce the time from hospital admission to PPCI and to increase the proportion of patients treated within 90 minutes. In March 2013 the authors launched a seven-component intervention program:  Direct patient evacuation by out-of-hospital emergency medical services to the coronary intensive care unit or catheterization laboratory Education program for the emergency department staff Dissemination of information regarding the urgency of the PPCI decision Activation of the catheterization team by a single phone call Reimbursement for transportation costs to on-call staff who use their own cars Improvement in the quality of medical records Investigation of failed cases and feedback. During the 14 months prior to the intervention, initiation of catheterization occurred within 90 minutes of hospital arrival in 88/133 patients(65%); during the 18 months following the start of the intervention, the rate was 181/200 (90%) (P < 0.01). The respective mean/median times to treatment were 126/67 minutes and 52/47 minutes (P < 0.01). Intervention also resulted in shortening of the time interval from hospital entry to PPCI on nights and weekends. Following implementation of a comprehensive intervention, the time from hospital admission to PPCI of STEMI patients shortened significantly, as did the proportion of patients treated within 90 minutes of hospital arrival.

  2. A strong focussing cylindrical electrostatic quadrupole

    International Nuclear Information System (INIS)

    Sheng Yaochang

    1986-01-01

    The construction and performance of small cylindrical electrostatic quadrupole, which is installed in JM-400 pulse electrostatic accelerator, are described. This electrostatic quadrupole is not only used in neutron generator, but also suitable for ion injector as well as for low energy electron accelerator

  3. Impact of Lipid Oxidization on Vertical Structures and Electrostatics of Phospholipid Monolayers Revealed by Combination of Specular X-ray Reflectivity and Grazing-Incidence X-ray Fluorescence.

    Science.gov (United States)

    Korytowski, Agatha; Abuillan, Wasim; Makky, Ali; Konovalov, Oleg; Tanaka, Motomu

    2015-07-30

    The influence of phospholipid oxidization of floating monolayers on the structure perpendicular to the global plane and on the density profiles of ions near the lipid monolayer has been investigated by a combination of grazing incidence X-ray fluorescence (GIXF) and specular X-ray reflectivity (XRR). Systematic variation of the composition of the floating monolayers unravels changes in the thickness, roughness and electron density of the lipid monolayers as a function of molar fraction of oxidized phospholipids. Simultaneous GIXF measurements enable one to qualitatively determine the element-specific density profiles of monovalent (K(+) or Cs(+)) and divalent ions (Ca(2+)) in the vicinity of the interface in the presence and absence of two types of oxidized phospholipids (PazePC and PoxnoPC) with high spatial accuracy (±5 Å). We found the condensation of Ca(2+) near carboxylated PazePC was more pronounced compared to PoxnoPC with an aldehyde group. In contrast, the condensation of monovalent ions could hardly be detected even for pure oxidized phospholipid monolayers. Moreover, pure phospholipid monolayers exhibited almost no ion specific condensation near the interface. The quantitative studies with well-defined floating monolayers revealed how the elevation of lipid oxidization level alters the structures and functions of cell membranes.

  4. Asteroid electrostatic instrumentation and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Aplin, K L; Bowles, N E; Urbak, E [Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Keane, D; Sawyer, E C, E-mail: k.aplin1@physics.ox.ac.uk [RAL Space, R25, Harwell Oxford, Didcot OX11 0QX (United Kingdom)

    2011-06-23

    Asteroid surface material is expected to become photoelectrically charged, and is likely to be transported through electrostatic levitation. Understanding any movement of the surface material is relevant to proposed space missions to return samples to Earth for detailed isotopic analysis. Motivated by preparations for the Marco Polo sample return mission, we present electrostatic modelling for a real asteroid, Itokawa, for which detailed shape information is available, and verify that charging effects are likely to be significant at the terminator and at the edges of shadow regions for the Marco Polo baseline asteroid, 1999JU3. We also describe the Asteroid Charge Experiment electric field instrumentation intended for Marco Polo. Finally, we find that the differing asteroid and spacecraft potentials on landing could perturb sample collection for the short landing time of 20min that is currently planned.

  5. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo

    2016-12-19

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  6. Electrostatic accelerators fundamentals and applications

    CERN Document Server

    2005-01-01

    Electrostatic accelerators are an important and widespread subgroup within the broad spectrum of modern, large particle acceleration devices. They are specifically designed for applications that require high-quality ion beams in terms of energy stability and emittance at comparatively low energies (a few MeV). Their ability to accelerate virtually any kind of ion over a continuously tunable range of energies make them a highly versatile tool for investigations in many research fields including, but not limited to, atomic and nuclear spectroscopy, heavy ion reactions, accelerator mass spectroscopy as well as ion-beam analysis and modification. The book is divided into three parts. The first part concisely introduces the field of accelerator technology and techniques that emphasize their major modern applications. The second part treats the electrostatic accelerator per se: its construction and operational principles as well as its maintenance. The third part covers all relevant applications in which electrosta...

  7. Frontier applications of electrostatic accelerators

    Science.gov (United States)

    Liu, Ke-Xin; Wang, Yu-Gang; Fan, Tie-Shuan; Zhang, Guo-Hui; Chen, Jia-Er

    2013-10-01

    Electrostatic accelerator is a powerful tool in many research fields, such as nuclear physics, radiation biology, material science, archaeology and earth sciences. Two electrostatic accelerators, one is the single stage Van de Graaff with terminal voltage of 4.5 MV and another one is the EN tandem with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at the Institute of Heavy Ion Physics. Many applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented.

  8. Tandem electrostatic accelerators for BNCT

    International Nuclear Information System (INIS)

    Ma, J.C.

    1994-01-01

    The development of boron neutron capture therapy (BNCT) into a viable therapeutic modality will depend, in part, on the availability of suitable neutron sources compatible with installation in a hospital environment. Low-energy accelerator-based intense neutron sources, using electrostatic or radio frequency quadrupole proton accelerators have been suggested for this purpose and are underdevelopment at several laboratories. New advances in tandem electrostatic accelerator technology now allow acceleration of the multi-milliampere proton beams required to produce therapeutic neutron fluxes for BNCT. The relatively compact size, low weight and high power efficiency of these machines make them particularly attractive for installation in a clinical or research facility. The authors will describe the limitations on ion beam current and available neutron flux from tandem accelerators relative to the requirements for BNCT research and therapy. Preliminary designs and shielding requirements for a tandern accelerator-based BNCT research facility will also be presented

  9. Digital electrostatic acoustic transducer array

    KAUST Repository

    Carreno, Armando Arpys Arevalo; Castro, David; Conchouso Gonzalez, David; Kosel, Jü rgen; Foulds, Ian G.

    2016-01-01

    In this paper we present the fabrication and characterization of an array of electrostatic acoustic transducers. The array is micromachined on a silicon wafer using standard micro-machining techniques. Each array contains 2n electrostatic transducer membranes, where “n” is the bit number. Every element of the array has a hexagonal membrane shape structure, which is separated from the substrate by 3µm air gap. The membrane is made out 5µm thick polyimide layer that has a bottom gold electrode on the substrate and a gold top electrode on top of the membrane (250nm). The wafer layout design was diced in nine chips with different array configurations, with variation of the membrane dimensions. The device was tested with 90 V giving and sound output level as high as 35dB, while actuating all the elements at the same time.

  10. Electrostatic septa for SPS extraction

    CERN Multimedia

    1975-01-01

    The extraction system for the N-Area is located in LSS2 (another one for the W-Area, now abandoned, was in LSS6). The electrostatic septum consists of 4 parts, each 3 m long. It is made of W-wires, 0.12 mm thick. The nominal electric field is 100 kV/cm. See also Annual Report 1975, p.175.

  11. Electrostatic coupling of ion pumps.

    Science.gov (United States)

    Nieto-Frausto, J; Lüger, P; Apell, H J

    1992-01-01

    In this paper the electrostatic interactions between membrane-embedded ion-pumps and their consequences for the kinetics of pump-mediated transport processes have been examined. We show that the time course of an intrinsically monomolecular transport reaction can become distinctly nonexponential, if the reaction is associated with charge translocation and takes place in an aggregate of pump molecules. First we consider the electrostatic coupling of a single dimer of ion-pumps embedded in the membrane. Then we apply the treatment to the kinetic analysis of light-driven proton transport by bacteriorhodopsin which forms two-dimensional hexagonal lattices. Finally, for the case of nonordered molecules, we also consider a model in which the pumps are randomly distributed over the nodes of a lattice. Here the average distance is equal to that deduced experimentally and the elemental size of the lattice is the effective diameter of one single pump. This latter model is applied to an aggregate of membrane-embedded Na, K- and Ca-pumps. In all these cases the electrostatic potential considered is the exact solution calculated from the method of electrical images for a plane membrane of finite thickness immersed in an infinite aqueous solution environment. The distributions of charges (ions or charged binding sites) are considered homogeneous or discrete in the membrane and/or in the external solution. In the case of discrete distributions we compare the results from a mean field approximation and a stochastic simulation.

  12. Quantitative nanoscale electrostatics of viruses.

    Science.gov (United States)

    Hernando-Pérez, M; Cartagena-Rivera, A X; Lošdorfer Božič, A; Carrillo, P J P; San Martín, C; Mateu, M G; Raman, A; Podgornik, R; de Pablo, P J

    2015-11-07

    Electrostatics is one of the fundamental driving forces of the interaction between biomolecules in solution. In particular, the recognition events between viruses and host cells are dominated by both specific and non-specific interactions and the electric charge of viral particles determines the electrostatic force component of the latter. Here we probe the charge of individual viruses in liquid milieu by measuring the electrostatic force between a viral particle and the Atomic Force Microscope tip. The force spectroscopy data of co-adsorbed ϕ29 bacteriophage proheads and mature virions, adenovirus and minute virus of mice capsids is utilized for obtaining the corresponding density of charge for each virus. The systematic differences of the density of charge between the viral particles are consistent with the theoretical predictions obtained from X-ray structural data. Our results show that the density of charge is a distinguishing characteristic of each virus, depending crucially on the nature of the viral capsid and the presence/absence of the genetic material.

  13. Some Design Considerations on the Electrostatically Actuated Fixed-Fixed End Type MEMS Switches

    International Nuclear Information System (INIS)

    Sadeghian, Hamed; Rezazadeh, Ghader; Sani, Ebrahim Abbaspour

    2006-01-01

    The nonlinear electrostatic pull-in behaviour of MEMS Switches in micro-electromechanical systems (MEMS) is investigated in this article. We used the distributed model when the electrostatic pressure didn't apply at the whole of the beam and applied only in the mid-part of the beam. In this part the electrostatic area is different from two other parts. The model uses Euler-Bernoulli beam theory for fixed-fixed end type beams. The finite difference method was used to solve the nonlinear equation. The proposed model includes the fringing effects of the electrical field, residual stress and varying electrostatic area effects. The numerical results reveal that the profile deflection of the MEMS Switch may not only influence the distribution of the electrostatic force but also considerably change the nonlinear pull-in voltage

  14. Nanoparticle electrostatic loss within corona needle charger during particle-charging process

    International Nuclear Information System (INIS)

    Huang Chenghsiung; Alonso, Manuel

    2011-01-01

    A numerical investigation has been carried out to examine the electrostatic loss of nanoparticles in a corona needle charger. Two-dimensional flow field, electric field, particle charge, and particle trajectory were simulated to obtain the electrostatic deposition loss at different conditions. Simulation of particle trajectories shows that the number of charges per particle during the charging process depends on the particle diameter, radial position from the symmetry axis, applied voltage, Reynolds number, and axial distance along the charger. The numerical results of nanoparticle electrostatic loss agreed fairly well with available experimental data. The results reveal that the electrostatic loss of nanoparticles increases with increasing applied voltage and electrical mobility of particles; and with decreasing particle diameter and Reynolds number. A regression equation closely fitted the obtained numerical results for different conditions. The equation is useful for directly calculating the electrostatic loss of nanoparticles in the corona needle charger during particle-charging process.

  15. Histopathologic evaluation of postmortem autolytic changes in bluegill (Lepomis macrohirus and crappie (Pomoxis anularis at varied time intervals and storage temperatures

    Directory of Open Access Journals (Sweden)

    Jami George

    2016-04-01

    Full Text Available Information is lacking on preserving fish carcasses to minimize postmortem autolysis artifacts when a necropsy cannot be performed immediately. The purpose of this study was to qualitatively identify and score histologic postmortem changes in two species of freshwater fish (bluegill—Lepomis macrochirus; crappie—Pomoxis annularis, at varied time intervals and storage temperatures, to assess the histologic quality of collected samples. A pooled sample of 36 mix sex individuals of healthy bluegill and crappie were euthanized, stored either at room temperature, refrigerated at 4 °C, or frozen at −20 °C, and then necropsied at 0, 4, 24, and 48 h intervals. Histologic specimens were evaluated by light microscopy. Data showed that immediate harvesting of fresh samples provides the best quality and refrigeration would be the preferred method of storage if sample collection had to be delayed for up to 24 h. When sample collection must be delayed more than 24 h, the preferred method of storage to minimize autolysis artifacts is freezing if evaluation of the gastrointestinal tract is most important, or refrigeration if gill histology is most important. The gill arch, intestinal tract, followed by the liver and kidney were the most sensitive organs to autolysis.

  16. neutron multiplicity measurements on 220 l waste drums containing Pu in the range 0.1-1 g 240Pueff with the time interval analysis method

    International Nuclear Information System (INIS)

    Baeten, P.; Bruggeman, M.; Carchon, R.; De Boeck, W.

    1998-01-01

    Measurement results are presented for the assay of plutonium in 220 l waste drums containing Pu-masses in the range 0.1-1 g 240 Pu eff obtained with the time interval analysis (TIA) method. TIA is a neutron multiplicity method based on the concept of one- and two-dimensional Rossi-alpha distributions. The main source of measurement bias in neutron multiplicity measurements at low count-rates is the impredictable variation of the high-multiplicity neutron background of spallation neutrons induced by cosmic rays. The TIA-method was therefore equipped with a special background filter, which is designed and optimized to reduce the influence of these spallation neutrons by rejecting the high-multiplicity events. The measurement results, obtained with the background correction filter outlined in this paper, prove the repeatability and validity of the TIA-method and show that multiplicity counting with the TIA-technique is applicable for masses as low as 0.1 g 240 Pu eff even at a detection efficiency of 12%. (orig.)

  17. Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study.

    Science.gov (United States)

    Kohli, Shivani; Bhatia, Shekhar

    2015-01-01

    Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI) and Acrylux (Ruthinium). Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal) and another group of each material in cola (Pepsi) as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi). The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

  18. Evaluation of the color durability of acrylic resin veneer materials after immersion in common beverages at different time intervals: A spectrophotometric study

    Directory of Open Access Journals (Sweden)

    Shivani Kohli

    2015-06-01

    Full Text Available Background: Proper function, esthetics, and cost are the prime factors to be considered while selecting bridge veneering materials. The purpose of the study is to evaluate color durability of acrylic veneer materials after immersion in common beverages at different time intervals. Methods: Spectrophotometer was used for taking color measurements based on the transmission of light through the specimens made of the selected materials which were Tooth moulding powder (DPI and Acrylux (Ruthinium. Thirty specimens of standardized dimensions were prepared from each material. The specimens were divided into three groups of 10 each. One group of each material was immersed in tea (TajMahal and another group of each material in cola (Pepsi as the staining solutions. The remaining group of 10 from each material served as control and was stored in distilled water. Color measurements were obtained pre-immersion, and after 1, 15, and 30 days of immersion. Results: Tooth moulding powder displayed better color durability than Acrylux over the 1 month immersion period in both staining solutions. Tea resulted in more discoloration compared to cola (Pepsi. Conclusion: The difference in the color durability of Acrylux and Tooth moulding powder may be attributed to the differences in the composition of tested resin veneering materials, i.e. their polar properties, which contribute to the absorption of staining solution, and the different brands and the strengths of the solutions.

  19. Irrigation Water Sources and Time Intervals as Variables on the Presence of Campylobacter spp. and Listeria monocytogenes on Romaine Lettuce Grown in Muck Soil.

    Science.gov (United States)

    Guévremont, Evelyne; Lamoureux, Lisyanne; Généreux, Mylène; Côté, Caroline

    2017-07-01

    Irrigation water has been identified as a possible source of vegetable contamination by foodborne pathogens. Risk management for pathogens such as Campylobacter spp. and Listeria monocytogenes in fields can be influenced by the source of the irrigation water and the time interval between last irrigation and harvest. Plots of romaine lettuce were irrigated with manure-contaminated water or aerated pond water 21, 7, or 3 days prior to harvesting, and water and muck soil samples were collected at each irrigation treatment. Lettuce samples were collected at the end of the trials. The samples were tested for the presence of Campylobacter spp. and L. monocytogenes. Campylobacter coli was isolated from 33% of hog manure samples (n = 9) and from 11% of the contaminated water samples (n = 27), but no lettuce samples were positive (n = 288). L. monocytogenes was not found in manure, and only one sample of manure-contaminated irrigation water (n = 27) and one lettuce sample (n = 288) were positive. No Campylobacter or L. monocytogenes was recovered from the soil samples (n = 288). Because of the low incidence of pathogens, it was not possible to link the contamination of either soil or lettuce with the type of irrigation water. Nevertheless, experimental field trials mimicking real conditions provide new insights into the survival of two significant foodborne pathogens on romaine lettuce.

  20. Studying DDT Susceptibility at Discriminating Time Intervals Focusing on Maximum Limit of Exposure Time Survived by DDT Resistant Phlebotomus argentipes (Diptera: Psychodidae): an Investigative Report.

    Science.gov (United States)

    Rama, Aarti; Kesari, Shreekant; Das, Pradeep; Kumar, Vijay

    2017-07-24

    Extensive application of routine insecticide i.e., dichlorodiphenyltrichloroethane (DDT) to control Phlebotomus argentipes (Diptera: Psychodidae), the proven vector of visceral leishmaniasis in India, had evoked the problem of resistance/tolerance against DDT, eventually nullifying the DDT dependent strategies to control this vector. Because tolerating an hour-long exposure to DDT is not challenging enough for the resistant P. argentipes, estimating susceptibility by exposing sand flies to insecticide for just an hour becomes a trivial and futile task.Therefore, this bioassay study was carried out to investigate the maximum limit of exposure time to which DDT resistant P. argentipes can endure the effect of DDT for their survival. The mortality rate of laboratory-reared DDT resistant strain P. argentipes exposed to DDT was studied at discriminating time intervals of 60 min and it was concluded that highly resistant sand flies could withstand up to 420 min of exposure to this insecticide. Additionally, the lethal time for female P. argentipes was observed to be higher than for males suggesting that they are highly resistant to DDT's toxicity. Our results support the monitoring of tolerance limit with respect to time and hence points towards an urgent need to change the World Health Organization's protocol for susceptibility identification in resistant P. argentipes.

  1. Radiofrequency ablation combined with transcatheter arterial embolisation in rabbit liver: investigation of the ablation zone according to the time interval between the two therapies.

    Science.gov (United States)

    Lee, I J; Kim, Y I; Kim, K W; Kim, D H; Ryoo, I; Lee, M W; Chung, J W

    2012-11-01

    This study was designed to evaluate the extent of the radiofrequency ablation zone in relation to the time interval between transcatheter arterial embolisation (TAE) and radiofrequency ablation (RFA) and, ultimately, to determine the optimal strategy of combining these two therapies for hepatocellular carcinoma. 15 rabbits were evenly divided into three groups: Group A was treated with RFA alone; Group B was treated with TAE immediately followed by RFA; and Group C was treated with TAE followed by RFA 5 days later. All animals underwent perfusion CT (PCT) scans immediately after RFA. Serum liver transaminases were measured to evaluate acute liver damage. Animals were euthanised for pathological analysis of ablated tissues 10 days after RFA. Non-parametric analyses were conducted to compare PCT indices, the RFA zone and liver transaminase levels among the three experimental groups. Group B showed a significantly larger ablation zone than the other two groups. Arterial liver perfusion and hepatic perfusion index represented well the perfusion decrease after TAE on PCT. Although Group B showed the most elevated liver transaminase levels at 1 day post RFA, the enzymes decreased to levels that were not different from the other groups at 10 days post-RFA. When combined TAE and RFA therapy is considered, TAE should be followed by RFA as quickly as possible, as it can be performed safely without serious hepatic deterioration, despite the short interval between the two procedures.

  2. Distortion of time interval reproduction in an epileptic patient with a focal lesion in the right anterior insular/inferior frontal cortices.

    Science.gov (United States)

    Monfort, Vincent; Pfeuty, Micha; Klein, Madelyne; Collé, Steffie; Brissart, Hélène; Jonas, Jacques; Maillard, Louis

    2014-11-01

    This case report on an epileptic patient suffering from a focal lesion at the junction of the right anterior insular cortex (AIC) and the adjacent inferior frontal cortex (IFC) provides the first evidence that damage to this brain region impairs temporal performance in a visual time reproduction task in which participants had to reproduce the presentation duration (3, 5 and 7s) of emotionally-neutral and -negative pictures. Strikingly, as compared to a group of healthy subjects, the AIC/IFC case considerably overestimated reproduction times despite normal variability. The effect was obtained in all duration and emotion conditions. Such a distortion in time reproduction was not observed in four other epileptic patients without insular or inferior frontal damage. Importantly, the absolute extent of temporal over-reproduction increased in proportion to the magnitude of the target durations, which concurs with the scalar property of interval timing, and points to an impairment of time-specific rather than of non temporal (such as motor) mechanisms. Our data suggest that the disability in temporal reproduction of the AIC/IFC case would result from a distorted memory representation of the encoded duration, occurring during the process of storage and/or of recovery from memory and leading to a deviation of the temporal judgment during the reproduction task. These findings support the recent proposal that the anterior insular/inferior frontal cortices would be involved in time interval representation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Graves’ Disease Causing Pancytopenia and Autoimmune Hemolytic Anemia at Different Time Intervals: A Case Report and a Review of the Literature

    Directory of Open Access Journals (Sweden)

    Peyman Naji

    2013-01-01

    Full Text Available Graves’ disease (GD is associated with various hematologic abnormalities but pancytopenia and autoimmune hemolytic anemia (AIHA are reported very rarely. Herein, we report a patient with GD who had both of these rare complications at different time intervals, along with a review of the related literature. The patient was a 70-year-old man who, during a hospitalization, was also noted to have pancytopenia and elevated thyroid hormone levels. Complete hematologic workup was unremarkable and his pancytopenia was attributed to hyperthyroidism. He was started on methimazole but unfortunately did not return for followup and stopped methimazole after a few weeks. A year later, he presented with fatigue and weight loss. Labs showed hyperthyroidism and isolated anemia (hemoglobin 7 g/dL. He had positive direct Coombs test and elevated reticulocyte index. He was diagnosed with AIHA and started on glucocorticoids. GD was confirmed with elevated levels of thyroid stimulating immunoglobulins and thyroid uptake and scan. He was treated with methimazole and radioactive iodine ablation. His hemoglobin improved to 10.7 g/dL at discharge without blood transfusion. Graves’ disease should be considered in the differential diagnosis of hematologic abnormalities. These abnormalities in the setting of GD generally respond well to antithyroid treatment.

  4. Late recovery of damage in rat spinal cord and bone marrow observed in split dose irradiation with long time intervals for 300 kV X-rays and 15 MeV neutrons

    International Nuclear Information System (INIS)

    Kogel, A.J. van der; Sissingh, H.A.

    The authors have performed an extended study on the capacity of the spinal cord for recovery of damage over long time intervals in split-dose experiments with 300 kV X-rays and 15 MeV neutrons, with time intervals of up to 30 weeks. The dose-response relationships for long term bone marrow depletion have been analysed and compared with those obtained for acute and late spinal cord damage. (Auth.)

  5. Electrostatic mechanism of nucleosomal array folding revealed by computer simulation.

    Science.gov (United States)

    Sun, Jian; Zhang, Qing; Schlick, Tamar

    2005-06-07

    Although numerous experiments indicate that the chromatin fiber displays salt-dependent conformations, the associated molecular mechanism remains unclear. Here, we apply an irregular Discrete Surface Charge Optimization (DiSCO) model of the nucleosome with all histone tails incorporated to describe by Monte Carlo simulations salt-dependent rearrangements of a nucleosomal array with 12 nucleosomes. The ensemble of nucleosomal array conformations display salt-dependent condensation in good agreement with hydrodynamic measurements and suggest that the array adopts highly irregular 3D zig-zag conformations at high (physiological) salt concentrations and transitions into the extended "beads-on-a-string" conformation at low salt. Energy analyses indicate that the repulsion among linker DNA leads to this extended form, whereas internucleosome attraction drives the folding at high salt. The balance between these two contributions determines the salt-dependent condensation. Importantly, the internucleosome and linker DNA-nucleosome attractions require histone tails; we find that the H3 tails, in particular, are crucial for stabilizing the moderately folded fiber at physiological monovalent salt.

  6. Electrostatics effects in granular materials

    Science.gov (United States)

    Sarkar, Saurabh; Chaudhuri, Bodhisattwa

    2013-06-01

    This purpose of this study is to investigate the role of physiochemical properties and operational conditions in determining the electrostatic interactions between two species on a surface under typical industrial conditions. The variables considered for the study were particle type, particle size and shape, loading mass, surface type, angle of inclination of chute, nature and concentration of additive. Triboelectrification of simple and binary mixtures in a simple hopper and chute geometry was observed to be strongly linked to work function and moisture content of the powdered material.

  7. Electrostatic potential map modelling with COSY Infinity

    International Nuclear Information System (INIS)

    Maloney, J.A.; Baartman, R.; Planche, T.; Saminathan, S.

    2016-01-01

    COSY Infinity (Makino and Berz, 2005) is a differential-algebra based simulation code which allows accurate calculation of transfer maps to arbitrary order. COSY’s existing internal procedures were modified to allow electrostatic elements to be specified using an array of field potential data from the midplane. Additionally, a new procedure was created allowing electrostatic elements and their fringe fields to be specified by an analytic function. This allows greater flexibility in accurately modelling electrostatic elements and their fringe fields. Applied examples of these new procedures are presented including the modelling of a shunted electrostatic multipole designed with OPERA, a spherical electrostatic bender, and the effects of different shaped apertures in an electrostatic beam line.

  8. Investigation on Electrostatical Breakup of Bio-Oil Droplets

    Directory of Open Access Journals (Sweden)

    John Z. Wen

    2012-10-01

    Full Text Available In electrostatic atomization, the input electrical energy causes breaking up of the droplet surface by utilizing a mutual repulsion of net charges accumulating on that surface. In this work a number of key parameters controlling the bio-oil droplet breakup process are identified and these correlations among the droplet size distribution, specific charges of droplets and externally applied electrical voltages are quantified. Theoretical considerations of the bag or strip breakup mechanism of biodiesel droplets experiencing electrostatic potential are compared to experimental outcomes. The theoretical analysis suggests the droplet breakup process is governed by the Rayleigh instability condition, which reveals the effects of droplets size, specific charge, surface tension force, and droplet velocities. Experiments confirm that the average droplet diameters decrease with increasing specific charges and this decreasing tendency is non-monotonic due to the motion of satellite drops in the non-uniform electrical field. The measured specific charges are found to be smaller than the theoretical values. And the energy transformation from the electrical energy to surface energy, in addition to the energy loss, Taylor instability breakup, non-excess polarization and some system errors, accounts for this discrepancy. The electrostatic force is the dominant factor controlling the mechanism of biodiesel breakup in electrostatic atomization.

  9. Simultaneous determination of environmental α-radionuclides using liquid scintillation counting combined with time interval analysis (TIA) and pulse shape discrimination (PSD)

    International Nuclear Information System (INIS)

    Hashimoto, T.; Sato, K.; Yoneyama, Y.; Fukuyama, N.

    1997-01-01

    Some improvements of the detection sensitivity in pulse time interval analysis (TIA) based on selective extraction of successively α-α correlated decay events within millisecond order from random or background events, were established by the utilization of PSD, to reject β/γ-pulses from α-ones and a simple chemical procedure of radium separation, together with the use of well resolved scintillator. By applying the PSD, the contribution of β-decay events was completely eliminated in both the α-spectra and the TIA distribution curves as well as the improvement into clear energy resolution and the enhancement of detection sensitivity for the TIA. As a result, the TIA and α-spectrometric analysis of 226 Ra-extract showed the existence of 223 Ra (Ac-series) and β/α-correlated events with correlated life (due to 0.16 ms due to 214 Bi(β)-> 214 Po(α)->) along with a singly well resolved α-peak to be useful for the determination of 226 Ra (U-series). The difference of half-lives (145 and 1.78 ms) due to 216 Po and 215 Po (direct daughters of 224 Ra for Th-series and 223 Ra for Ac-series, respectively) was also proven for the possibility of the simultaneous determination of both correlated events by using the TIA/PSD combined with chemical separation and liquid scintillation counting method. Finally, the simultaneous determination of three natural decay series, which include U-, Th- and Ac-series nuclides, have been conveniently carried out for some environmental samples using the present method combined with 225 Ra yield tracer (Np-series). (author)

  10. An automatic device for refilling liquid nitrogen traps at constant time intervals; Dispositif automatique assurant le remplissage de pieces en azote liquide a intervales de temps constant

    Energy Technology Data Exchange (ETDEWEB)

    Bourguillot, R; Lohez, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    We have been led to study the design of an automatic device for the filling of liquid nitrogen traps at constant time intervals in connection with the maintenance of a type MS 5 mass spectrometer; in the tube of this apparatus it is necessary to maintain a vacuum of about 10{sup -7} mm of mercury. The replenishing is done every four hours. The presence in the vacuum section of an electron multiplier has led us to provide a safety-device making it impossible for mercury vapour to come into contact with either the copper tube or the multiplier in the event of an incident leading to the warming up of the traps. In case of a breakdown, the vacuum section is therefore brought up to atmospheric pressure by the introduction of nitrogen. (author) [French] Nous avons ete conduits pour la maintenance d'un spectrometre de masse type MS 5, dans le tube duquel il faut entretenir un vide de quelques 10{sup -7} mm de mercure, a etudier un systeme de remplissage automatique a intervalle de temps fixe des pieges en azote liquide. Ce remplissage se fait toutes les quatre heures. La presence dans l'enceinte sous vide, d'un multiplicateur d'electrons, nous a amenes a prevoir un systeme de securite evitant de mettre le tube en cuivre et le multiplicateur en contact avec la vapeur de mercure en cas d'incident amenant le rechauffage des pieges. En cas de panne, l'enceinte sous vide est donc ramenee a la pression atmospherique par une introduction d'azote. (auteur)

  11. Shear bond strength of composite to deep dentin after treatment with two different collagen cross-linking agents at varying time intervals.

    Science.gov (United States)

    Srinivasulu, S; Vidhya, S; Sujatha, M; Mahalaxmi, S

    2012-01-01

    This in vitro study evaluated the shear bond strength of composite resin to deep dentin using a total etch adhesive after treatment with two collagen cross-linking agents at varying time intervals. Thirty freshly extracted human maxillary central incisors were sectioned longitudinally into equal mesial and distal halves (n=60). The proximal deep dentin was exposed, maintaining a remaining dentin thickness (RDT) of approximately 1 mm. The specimens were randomly divided into three groups based on the surface treatment of dentin prior to bonding as follows: group I (n=12, control): no prior dentin surface treatment; group II (n=24): dentin surface pretreated with 10% sodium ascorbate; and group III (n=24): dentin surface pretreated with 6.5% proanthocyanidin. Groups II and III were further subdivided into two subgroups of 12 specimens each, based on the pretreatment time of five minutes (subgroup A) and 10 minutes (subgroup B). Shear bond strength of the specimens was tested with a universal testing machine, and the data were statistically analyzed. Significantly higher shear bond strength to deep dentin was observed in teeth treated with 10% sodium ascorbate (group II) and 6.5% proanthocyanidin (group III) compared to the control group (group I). Among the collagen cross-linkers used, specimens treated with proanthocyanidin showed significantly higher shear bond strength values than those treated with sodium ascorbate. No significant difference was observed between the five-minute and 10-minute pretreatment times in groups II and III. It can be concluded that dentin surface pretreatment with both 10% sodium ascorbate and 6.5% proanthocyanidin resulted in significant improvement in bond strength of resin composite to deep dentin.

  12. Effect of the time interval between fusion and activation on epigenetic reprogramming and development of bovine somatic cell nuclear transfer embryos.

    Science.gov (United States)

    Liu, Jun; Wang, Yongsheng; Su, Jianmin; Wang, Lijun; Li, Ruizhe; Li, Qian; Wu, Yongyan; Hua, Song; Quan, Fusheng; Guo, Zekun; Zhang, Yong

    2013-04-01

    Previous studies have shown that the time interval between fusion and activation (FA interval) play an important role in nuclear remodeling and in vitro development of somatic cell nuclear transfer (SCNT) embryos. However, the effects of FA interval on the epigenetic reprogramming and in vivo developmental competence of SCNT embryos remain unknown. In the present study, the effects of different FA intervals (0 h, 2 h, and 4 h) on the epigenetic reprogramming and developmental competence of bovine SCNT embryos were assessed. The results demonstrated that H3 lysine 9 (H3K9ac) levels decreased rapidly after fusion in all three groups. H3K9ac was practically undetectable 2 h after fusion in the 2-h and 4-h FA interval groups. However, H3K9ac was still evidently detectable in the 0-h FA interval group. The H3K9ac levels increased 10 h after fusion in all three groups, but were higher in the 2-h and 4-h FA interval groups than that in the 0-h FA interval group. The methylation levels of the satellite I region in day-7 blastocysts derived from the 2-h or 4-h FA interval groups was similar to that of in vitro fertilization blastocysts and is significantly lower than that of the 0-h FA interval group. SCNT embryos derived from 2-h FA interval group showed higher developmental competence than those from the 0-h and 4-h FA interval groups in terms of cleavage rate, blastocyst formation rate, apoptosis index, and pregnancy and calving rates. Hence, the FA interval is an important factor influencing the epigenetic reprogramming and developmental competence of bovine SCNT embryos.

  13. Electrostatics in pharmaceutical aerosols for inhalation.

    Science.gov (United States)

    Wong, Jennifer; Chan, Hak-Kim; Kwok, Philip Chi Lip

    2013-08-01

    Electrostatics continues to play an important role in pharmaceutical aerosols for inhalation. Despite its ubiquitous nature, the charging process is complex and not well understood. Nonetheless, significant advances in the past few years continue to improve understanding and lead to better control of electrostatics. The purpose of this critical review is to present an overview of the literature, with an emphasis on how electrostatic charge can be useful in improving pulmonary drug delivery.

  14. Electrostatic Climber for Space Elevator and Launcher

    OpenAIRE

    Bolonkin, A.

    2007-01-01

    Author details research on the new, very prospective, electrostatic Space Elevator climber based on a new electrostatic linear engine previously offered at the 42nd Joint Propulsion Conference (AIAA-2006-5229) and published in AEAT, Vol.78, No.6, 2006, pp. 502-508. The electrostatic climber discussed can have any speed (and braking), the energy for climber movement is delivered by a lightweight high-voltage line into a Space Elevator-holding cable from Earth electric generator. This electric ...

  15. Application of Electrostatic Extrusion – Flavour Encapsulation and Controlled Release

    OpenAIRE

    Manojlovic, Verica; Rajic, Nevenka; Djonlagic, Jasna; Obradovic, Bojana; Nedovic, Viktor; Bugarski, Branko

    2008-01-01

    The subject of this study was the development of flavour alginate formulations aimed for thermally processed foods. Ethyl vanilline was used as the model flavour compound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline in alginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethyl vanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about 450 ?m. Chemical characterization by H-NMR spectroscopy revealed that the algi...

  16. Preconceptual design for the electrostatic enclosure

    International Nuclear Information System (INIS)

    Meyer, L.C.

    1992-09-01

    This report presents a preconceptual design (design criteria and assumptions) for electrostatic enclosures to be used during buried transuranic waste recovery operations. These electrostatic enclosures (along with the application of dust control products) will provide an in-depth contamination control strategy. As part of this preconceptual design, options for electrostatic curtain design are given including both hardwall and fabric enclosures. Ventilation systems, doors, air locks, electrostatic curtains, and supporting systems also are discussed. In addition to the conceptual design, engineering scale tests are proposed to be run at the Test Reactor Area. The planned engineering scale tests will give final material specifications for full-scale retrieval demonstrations

  17. Limiting assumptions in molecular modeling: electrostatics.

    Science.gov (United States)

    Marshall, Garland R

    2013-02-01

    Molecular mechanics attempts to represent intermolecular interactions in terms of classical physics. Initial efforts assumed a point charge located at the atom center and coulombic interactions. It is been recognized over multiple decades that simply representing electrostatics with a charge on each atom failed to reproduce the electrostatic potential surrounding a molecule as estimated by quantum mechanics. Molecular orbitals are not spherically symmetrical, an implicit assumption of monopole electrostatics. This perspective reviews recent evidence that requires use of multipole electrostatics and polarizability in molecular modeling.

  18. Industrial Electrostatic-Gecko Gripper, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Perception Robotics is developing an innovative product, the Electrostatic Gecko Gripper? (ESG Gripper), for the industrial automation market. This unique gripping...

  19. Industrial Electrostatic-Gecko Gripper, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Perception Robotics is developing an innovative product, the "Electrostatic Gecko Gripper" (ESG Gripper), for the industrial automation market. This unique gripping...

  20. Optics elements for modeling electrostatic lenses and accelerator components: III. Electrostatic deflectors

    International Nuclear Information System (INIS)

    Brown, T.A.; Gillespie, G.H.

    2000-01-01

    Ion-beam optics models for simulating electrostatic prisms (deflectors) of different geometries have been developed for the envelope (matrix) computer code TRACE 3-D as a part of the development of a suite of electrostatic beamline element models which includes lenses, acceleration columns, quadrupoles and prisms. The models for electrostatic prisms are described in this paper. The electrostatic prism model options allow the first-order modeling of cylindrical, spherical and toroidal electrostatic deflectors. The application of these models in the development of ion-beam transport systems is illustrated through the modeling of a spherical electrostatic analyzer as a component of the new low-energy beamline at the Center for Accelerator Mass Spectrometry. Although initial tests following installation of the new beamline showed that the new spherical electrostatic analyzer was not behaving as predicted by these first-order models, operational conditions were found under which the analyzer now works properly as a double-focusing spherical electrostatic prism

  1. Electrostatic analogy for symmetron gravity

    Science.gov (United States)

    Ogden, Lillie; Brown, Katherine; Mathur, Harsh; Rovelli, Kevin

    2017-12-01

    The symmetron model is a scalar-tensor theory of gravity with a screening mechanism that suppresses the effect of the symmetron field at high densities characteristic of the Solar System and laboratory scales but allows it to act with gravitational strength at low density on the cosmological scale. We elucidate the screening mechanism by showing that in the quasistatic Newtonian limit there are precise analogies between symmetron gravity and electrostatics for both strong and weak screening. For strong screening we find that large dense bodies behave in a manner analogous to perfect conductors in electrostatics. Based on this analogy we find that the symmetron field exhibits a lightning rod effect wherein the field gradients are enhanced near the ends of pointed or elongated objects. An ellipsoid placed in a uniform symmetron gradient is shown to experience a torque. By symmetry there is no gravitational torque in this case. Hence this effect unmasks the symmetron and might serve as the basis for future laboratory experiments. The symmetron force between a point mass and a large dense body includes a component corresponding to the interaction of the point mass with its image in the larger body. None of these effects have counterparts in the Newtonian limit of Einstein gravity. We discuss the similarities between symmetron gravity and the chameleon model as well as the differences between the two.

  2. Highly Tunable Electrostatic Nanomechanical Resonators

    KAUST Repository

    Kazmi, Syed Naveed Riaz

    2017-11-24

    There has been significant interest towards highly tunable resonators for on-demand frequency selection in modern communication systems. Here, we report highly tunable electrostatically actuated silicon-based nanomechanical resonators. In-plane doubly-clamped bridges, slightly curved as shallow arches due to residual stresses, are fabricated using standard electron beam lithography and surface nanomachining. The resonators are designed such that the effect of mid-plane stretching dominates the softening effect of the electrostatic force. This is achieved by controlling the gap-to-thickness ratio and by exploiting the initial curvature of the structure from fabrication. We demonstrate considerable increase in the resonance frequency of nanoresonators with the dc bias voltages up to 108% for 180 nm thick structures with a transduction gap of 1 $mu$m separating them from the driving/sensing electrodes. The experimental results are found in good agreement with those of a nonlinear analytical model based on the Euler-Bernoulli beam theory. As a potential application, we demonstrate a tunable narrow band-pass filter using two electrically coupled nanomechanical arch resonators with varied dc bias voltages.

  3. Highly Tunable Electrostatic Nanomechanical Resonators

    KAUST Repository

    Kazmi, Syed Naveed Riaz; Hajjaj, Amal Z.; Hafiz, Md Abdullah Al; Da Costa, Pedro M. F. J.; Younis, Mohammad I.

    2017-01-01

    There has been significant interest towards highly tunable resonators for on-demand frequency selection in modern communication systems. Here, we report highly tunable electrostatically actuated silicon-based nanomechanical resonators. In-plane doubly-clamped bridges, slightly curved as shallow arches due to residual stresses, are fabricated using standard electron beam lithography and surface nanomachining. The resonators are designed such that the effect of mid-plane stretching dominates the softening effect of the electrostatic force. This is achieved by controlling the gap-to-thickness ratio and by exploiting the initial curvature of the structure from fabrication. We demonstrate considerable increase in the resonance frequency of nanoresonators with the dc bias voltages up to 108% for 180 nm thick structures with a transduction gap of 1 $mu$m separating them from the driving/sensing electrodes. The experimental results are found in good agreement with those of a nonlinear analytical model based on the Euler-Bernoulli beam theory. As a potential application, we demonstrate a tunable narrow band-pass filter using two electrically coupled nanomechanical arch resonators with varied dc bias voltages.

  4. Electrostatic phenomena in volcanic eruptions

    Energy Technology Data Exchange (ETDEWEB)

    Lane, S J; James, M R; Gilbert, J S, E-mail: s.lane@lancaster.ac.uk [Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ (United Kingdom)

    2011-06-23

    Electrostatic phenomena have long been associated with the explosive eruption of volcanoes. Lightning generated in volcanic plumes is a spectacular atmospheric electrical event that requires development of large potential gradients over distances of up to kilometres. This process begins as hydrated liquid rock (magma) ascends towards Earth's surface. Pressure reduction causes water supersaturation in the magma and the development of bubbles of supercritical water, where deeper than c. 1000 m, and water vapour at shallower depths that drives flow expansion. The generation of high strain rates in the expanding bubbly magma can cause it to fracture in a brittle manner, as deformation relaxation timescales are exceeded. The brittle fracture provides the initial charge separation mechanism, known as fractoemission. The resulting mixture of charged silicate particles and ions evolves over time, generating macro-scale potential gradients in the atmosphere and driving processes such as particle aggregation. For the silicate particles, aggregation driven by electrostatic effects is most significant for particles smaller than c. 100 {mu}m. Aggregation acts to change the effective aerodynamic behaviour of silicate particles, thus altering the sedimentation rates of particles from volcanic plumes from the atmosphere. The presence of liquid phases also promotes aggregation processes and lightning.

  5. Microencapsulation and Electrostatic Processing Device

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor); Cassanto, John M. (Inventor)

    2001-01-01

    A microencapsulation and electrostatic processing (MEP) device is provided for forming microcapsules. In one embodiment, the device comprises a chamber having a filter which separates a first region in the chamber from a second region in the chamber. An aqueous solution is introduced into the first region through an inlet port, and a hydrocarbon/ polymer solution is introduced into the second region through another inlet port. The filter acts to stabilize the interface and suppress mixing between the two immiscible solutions as they are being introduced into their respective regions. After the solutions have been introduced and have become quiescent, the interface is gently separated from the filter. At this point, spontaneous formation of microcapsules at the interface may begin to occur, or some fluid motion may be provided to induce microcapsule formation. In any case, the fluid shear force at the interface is limited to less than 100 dynes/sq cm. This low-shear approach to microcapsule formation yields microcapsules with good sphericity and desirable size distribution. The MEP device is also capable of downstream processing of microcapsules, including rinsing, re-suspension in tertiary fluids, electrostatic deposition of ancillary coatings, and free-fluid electrophoretic separation of charged microcapsules.

  6. Electrostatic discharge concepts and definitions

    Energy Technology Data Exchange (ETDEWEB)

    Borovina, Dan L [Los Alamos National Laboratory

    2008-01-01

    Many objects -like a human body, plastic wrap, or a rolling cart -that are electrically neutral, overall, can gain a net electrostatic charge by means of one of three methods: induction, physical transfer, or triboelectric charging (separation of conductive surfaces). The result is a voltage difference between the charged object and other objects, creating a situation where current flow is likely if two objects come into contact or close proximity. This current flow is known as electrostatic discharge, or ESD. The energy and voltage of the discharge can be influenced by factors such as the temperature and humidity in the room, the types of materials or flooring involved, or the clothing and footwear a person uses. Given the possible ranges of the current and voltage characteristic of an ESD pulse, it is important to consider the safety risks associated with detonator handling, assembly and disassembly, transportation and maintenance. For main charge detonators, these safety risks include high explosive violent reactions (HEVR) as well as inadvertent nuclear detonations (lND).

  7. Comparison of yoga and walking-exercise on cardiac time intervals as a measure of cardiac function in elderly with increased pulse pressure.

    Science.gov (United States)

    Patil, Satish Gurunathrao; Patil, Shankargouda S; Aithala, Manjunatha R; Das, Kusal Kanti

    Arterial aging along with increased blood pressure(BP) has become the major cardiovascular(CV) risk in elderly. The aim of the study was to compare the effects of yoga program and walking-exercise on cardiac function in elderly with increased pulse pressure (PP). An open label, parallel-group randomized controlled study design was adopted. Elderly individuals aged ≥60 years with PP≥60mmHg were recruited for the study. Yoga (study) group (n=30) was assigned for yoga training and walking (exercise) group (n=30) for walking with loosening practices for one hour in the morning for 6days in a week for 3 months. The outcome measures were cardiac time intervals derived from pulse wave analysis and ECG: resting heart rate (RHR), diastolic time(DT), ventricular ejection time(LVET), upstroke time(UT), ejection duration index (ED%), pre-ejection period (PEP), rate pressure product (RPP) and percentage of mean arterial pressure (%MAP). The mean within-yoga group change in RHR(bpm) was 4.41 (p=0.031), PD(ms): -50.29 (p=0.042), DT(ms): -49.04 (p=0.017), ED%: 2.107 (p=0.001), ES(mmHg/ms): 14.62 (p=0.118), ET(ms): -0.66 (p=0.903), UT(ms): -2.54 (p=0.676), PEP(ms): -1.25 (p=0.11) and %MAP: 2.08 (p=0.04). The mean within-control group change in HR (bpm) was 0.35 (p=0.887), PD (ms): 11.15(p=0.717), DT (ms): 11.3 (p=0.706), ED%: -0.101 (p=0.936), ES (mmHg/ms): 0.75 (p=0.926), ET(ms): 2.2 (p=0.721), UT(ms):4.7(p=455), PEP (ms): 2.1(p=0.11), %MAP: 0.65 (p=0.451). A significant difference between-group was found in RHR (p=0.036), PD (p=0.02), ED% (p=0.049), LVET (p=0.048), DT (p=0.02) and RPP (p=0.001). Yoga practice for 3 months showed a significant improvement in diastolic function with a minimal change in systolic function. Yoga is more effective than walking in improving cardiac function in elderly with high PP. Copyright © 2017 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

  8. Electrostatics with Computer-Interfaced Charge Sensors

    Science.gov (United States)

    Morse, Robert A.

    2006-01-01

    Computer interfaced electrostatic charge sensors allow both qualitative and quantitative measurements of electrostatic charge but are quite sensitive to charges accumulating on modern synthetic materials. They need to be used with care so that students can correctly interpret their measurements. This paper describes the operation of the sensors,…

  9. Preliminary tests of the electrostatic plasma accelerator

    Science.gov (United States)

    Aston, G.; Acker, T.

    1990-01-01

    This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply.

  10. Large Aperture Electrostatic Dust Detector

    International Nuclear Information System (INIS)

    Skinner, C.H.; Hensley, R.; Roquemore, A.L.

    2007-01-01

    Diagnosis and management of dust inventories generated in next-step magnetic fusion devices is necessary for their safe operation. A novel electrostatic dust detector, based on a fine grid of interlocking circuit traces biased to 30 or 50 v has been developed for the detection of dust particles on remote surfaces in air and vacuum environments. Impinging dust particles create a temporary short circuit and the resulting current pulse is recorded by counting electronics. Up to 90% of the particles are ejected from the grid or vaporized suggesting the device may be useful for controlling dust inventories. We report measurements of the sensitivity of a large area (5x5 cm) detector to microgram quantities of dust particles and review its applications to contemporary tokamaks and ITER.

  11. Take-Home Electrostatics Experiments

    Science.gov (United States)

    Brown, Michael H.

    1997-10-01

    Important concepts in electrostatics can be taught using apparatus that students can find or build at home. A TV or monitor screens serves as the source of a strong electric field (10,000 V/m). It can be used to charge a capacitor made from foil-covered cardboard plates supported by the bottom of a plastic pop bottle. A foil ball suspended between the plates transfers charges in a version of Franklin's experiment. An electric dipole compass,made of carnauba wax polarized in the electric field of the TV, can be used to map the fringing field of the capacitor. Discharge of charged foil-covered balls produces ``static'' that can be detected with an AM radio. *supported in part by NSF CCD grant DUE-9555215

  12. Microencapsulation and Electrostatic Processing Method

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2000-01-01

    Methods are provided for forming spherical multilamellar microcapsules having alternating hydrophilic and hydrophobic liquid layers, surrounded by flexible, semi-permeable hydrophobic or hydrophilic outer membranes which can be tailored specifically to control the diffusion rate. The methods of the invention rely on low shear mixing and liquid-liquid diffusion process and are particularly well suited for forming microcapsules containing both hydrophilic and hydrophobic drugs. These methods can be carried out in the absence of gravity and do not rely on density-driven phase separation, mechanical mixing or solvent evaporation phases. The methods include the process of forming, washing and filtering microcapsules. In addition, the methods contemplate coating microcapsules with ancillary coatings using an electrostatic field and free fluid electrophoresis of the microcapsules. The microcapsules produced by such methods are particularly useful in the delivery of pharmaceutical compositions.

  13. Electrostatic effect for the collisionless tearing mode

    International Nuclear Information System (INIS)

    Hoshino, M.

    1987-01-01

    Electron dynamics has not been self-consistently considered in collisionless tearing mode theories to date because of the mathematical complexity of the Vlasov-Maxwell equations. We have found using computer simulations that electrostatic fields play an important role in the tearing mode. Vlasov theory, including the electrostatic field, is investigated for topologies with both antiparallel and nonantiparallel magnetic field lines. The electrostatic field influences the resonant current in the neutral sheet which is a non-MHD effect, and modifies the linear growth rate. At the magnetopause, where the field lines are not antiparallel, the electrostatic effect acts to raise the linear growth rate of the tearing mode. On the other hand, in the magnetotail, where magnetic field lines are antiparallel, the electrostatic effect reduces the tearing mode growth rate. copyright American Geophysical Union 1987

  14. Electrostatics-Driven Hierarchical Buckling of Charged Flexible Ribbons.

    Science.gov (United States)

    Yao, Zhenwei; Olvera de la Cruz, Monica

    2016-04-08

    We investigate the rich morphologies of an electrically charged flexible ribbon, which is a prototype for many beltlike structures in biology and nanomaterials. Long-range electrostatic repulsion is found to govern the hierarchical buckling of the ribbon from its initially flat shape to its undulated and out-of-plane twisted conformations. In this process, the screening length is the key controlling parameter, suggesting that a convenient way to manipulate the ribbon morphology is simply to change the salt concentration. We find that these shapes originate from the geometric effect of the electrostatic interaction, which fundamentally changes the metric over the ribbon surface. We also identify the basic modes by which the ribbon reshapes itself in order to lower the energy. The geometric effect of the physical interaction revealed in this Letter has implications for the shape design of extensive ribbonlike materials in nano- and biomaterials.

  15. Does the time interval between antimüllerian hormone serum sampling and initiation of ovarian stimulation affect its predictive ability in in vitro fertilization-intracytoplasmic sperm injection cycles with a gonadotropin-releasing hormone antagonist?

    DEFF Research Database (Denmark)

    Polyzos, Nikolaos P; Nelson, Scott M; Stoop, Dominic

    2013-01-01

    To investigate whether the time interval between serum antimüllerian hormone (AMH) sampling and initiation of ovarian stimulation for in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) may affect the predictive ability of the marker for low and excessive ovarian response.......To investigate whether the time interval between serum antimüllerian hormone (AMH) sampling and initiation of ovarian stimulation for in vitro fertilization-intracytoplasmic sperm injection (IVF-ICSI) may affect the predictive ability of the marker for low and excessive ovarian response....

  16. Prognostic Value of Cardiac Time Intervals by Tissue Doppler Imaging M-Mode in Patients With Acute ST-Segment-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

    DEFF Research Database (Denmark)

    Biering-Sørensen, Tor; Mogelvang, Rasmus; Søgaard, Peter

    2013-01-01

    Background- Color tissue Doppler imaging M-mode through the mitral leaflet is an easy and precise method to estimate all cardiac time intervals from 1 cardiac cycle and thereby obtain the myocardial performance index (MPI). However, the prognostic value of the cardiac time intervals and the MPI...... assessed by color tissue Doppler imaging M-mode through the mitral leaflet in patients with ST-segment-elevation myocardial infarction (MI) is unknown. Methods and Results- In total, 391 patients were admitted with an ST-segment-elevation MI, treated with primary percutaneous coronary intervention...

  17. Study of talcum charging status in parallel plate electrostatic separator based on particle trajectory analysis

    Science.gov (United States)

    Yunxiao, CAO; Zhiqiang, WANG; Jinjun, WANG; Guofeng, LI

    2018-05-01

    Electrostatic separation has been extensively used in mineral processing, and has the potential to separate gangue minerals from raw talcum ore. As for electrostatic separation, the particle charging status is one of important influence factors. To describe the talcum particle charging status in a parallel plate electrostatic separator accurately, this paper proposes a modern images processing method. Based on the actual trajectories obtained from sequence images of particle movement and the analysis of physical forces applied on a charged particle, a numerical model is built, which could calculate the charge-to-mass ratios represented as the charging status of particle and simulate the particle trajectories. The simulated trajectories agree well with the experimental results obtained by images processing. In addition, chemical composition analysis is employed to reveal the relationship between ferrum gangue mineral content and charge-to-mass ratios. Research results show that the proposed method is effective for describing the particle charging status in electrostatic separation.

  18. DelPhiForce web server: electrostatic forces and energy calculations and visualization.

    Science.gov (United States)

    Li, Lin; Jia, Zhe; Peng, Yunhui; Chakravorty, Arghya; Sun, Lexuan; Alexov, Emil

    2017-11-15

    Electrostatic force is an essential component of the total force acting between atoms and macromolecules. Therefore, accurate calculations of electrostatic forces are crucial for revealing the mechanisms of many biological processes. We developed a DelPhiForce web server to calculate and visualize the electrostatic forces at molecular level. DelPhiForce web server enables modeling of electrostatic forces on individual atoms, residues, domains and molecules, and generates an output that can be visualized by VMD software. Here we demonstrate the usage of the server for various biological problems including protein-cofactor, domain-domain, protein-protein, protein-DNA and protein-RNA interactions. The DelPhiForce web server is available at: http://compbio.clemson.edu/delphi-force. delphi@clemson.edu. Supplementary data are available at Bioinformatics online. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

  19. Geometry-Dependent Electrostatics near Contact Lines

    International Nuclear Information System (INIS)

    Chou, Tom

    2001-01-01

    Long-ranged electrostatic interactions in electrolytes modify contact angles on charged substrates in a scale and geometry-dependent manner. For angles measured at scales smaller than the typical Debye screening length, the wetting geometry near the contact line must be explicitly considered. Using variational and asymptotic methods, we derive new transcendental equations for the contact angle as functions of the electrostatic potential only at the three phase contact line. Analytic expressions are found in certain limits and compared with predictions for contact angles measured with lower resolution. An estimate for electrostatic contributions to line tension is also given

  20. Nonlinear dynamics of resistive electrostatic drift waves

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang; Michelsen, Poul; Pécseli, H.L.

    1999-01-01

    The evolution of weakly nonlinear electrostatic drift waves in an externally imposed strong homogeneous magnetic field is investigated numerically in three spatial dimensions. The analysis is based on a set of coupled, nonlinear equations, which are solved for an initial condition which is pertur......The evolution of weakly nonlinear electrostatic drift waves in an externally imposed strong homogeneous magnetic field is investigated numerically in three spatial dimensions. The analysis is based on a set of coupled, nonlinear equations, which are solved for an initial condition which...... polarity, i.e. a pair of electrostatic convective cells....

  1. Introduction to numerical electrostatics using MATLAB

    CERN Document Server

    Dworsky, Lawrence N

    2014-01-01

    The first of its kind uniquely devoted to the field of computational electrostatics, this book dives headfirst into the actual problems that engineers are expected to solve using method of moment (MoM), finite difference, and finite element techniques. Readers are guided step by step through specific problems and challenges, covering all aspects of electrostatics with an emphasis on numerical procedures. Focusing on practical examples, mathematical equations, and common issues with algorithms, this is an ideal text for students in engineering, physics, and electrostatics-and working engineers

  2. Count-to-count time interval distribution analysis in a fast reactor; Estudio de la distribucion de intervalos de tiempo entre detecciones consecutivas de neutrones en un reactor rapido

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Navarro Gomez, A

    1973-07-01

    The most important kinetic parameters have been measured at the zero power fast reactor CORAL-I by means of the reactor noise analysis in the time domain, using measurements of the count-to-count time intervals. (Author) 69 refs.

  3. Internal Electrostatic Discharge Monitor - IESDM

    Science.gov (United States)

    Kim, Wousik; Goebel, Dan M.; Jun, Insoo; Garrett, Henry B.

    2011-01-01

    A document discusses an innovation designed to effectively monitor dielectric charging in spacecraft components to measure the potential for discharge in order to prevent damage from internal electrostatic discharge (IESD). High-energy electrons penetrate the structural materials and shielding of a spacecraft and then stop inside dielectrics and keep accumulating. Those deposited charges generate an electric field. If the electric field becomes higher than the breakdown threshold (approx. =2 x 10(exp 5) V/cm), discharge occurs. This monitor measures potentials as a function of dielectric depth. Differentiation of potential with respect to the depth yields electric field. Direct measurement of the depth profile of the potential in a dielectric makes real-time electronic field evaluation possible without simulations. The IESDM has been designed to emulate a multi-layer circuit board, to insert very thin metallic layers between the dielectric layers. The conductors serve as diagnostic monitoring locations to measure the deposited electron-charge and the charge dynamics. Measurement of the time-dependent potential of the metal layers provides information on the amount of charge deposited in the dielectrics and the movement of that charge with time (dynamics).

  4. Effects of electrostatic interactions on ligand dissociation kinetics

    Science.gov (United States)

    Erbaş, Aykut; de la Cruz, Monica Olvera; Marko, John F.

    2018-02-01

    We study unbinding of multivalent cationic ligands from oppositely charged polymeric binding sites sparsely grafted on a flat neutral substrate. Our molecular dynamics simulations are suggested by single-molecule studies of protein-DNA interactions. We consider univalent salt concentrations spanning roughly a 1000-fold range, together with various concentrations of excess ligands in solution. To reveal the ionic effects on unbinding kinetics of spontaneous and facilitated dissociation mechanisms, we treat electrostatic interactions both at a Debye-Hückel (DH) (or implicit ions, i.e., use of an electrostatic potential with a prescribed decay length) level and by the more precise approach of considering all ionic species explicitly in the simulations. We find that the DH approach systematically overestimates unbinding rates, relative to the calculations where all ion pairs are present explicitly in solution, although many aspects of the two types of calculation are qualitatively similar. For facilitated dissociation (FD) (acceleration of unbinding by free ligands in solution) explicit-ion simulations lead to unbinding at lower free-ligand concentrations. Our simulations predict a variety of FD regimes as a function of free-ligand and ion concentrations; a particularly interesting regime is at intermediate concentrations of ligands where nonelectrostatic binding strength controls FD. We conclude that explicit-ion electrostatic modeling is an essential component to quantitatively tackle problems in molecular ligand dissociation, including nucleic-acid-binding proteins.

  5. Nonlinear Dynamics of Electrostatically Actuated MEMS Arches

    KAUST Repository

    Al Hennawi, Qais M.

    2015-01-01

    In this thesis, we present theoretical and experimental investigation into the nonlinear statics and dynamics of clamped-clamped in-plane MEMS arches when excited by an electrostatic force. Theoretically, we first solve the equation of motion using

  6. The Electrostatic Actuated Next Generation Microshutter Arrays

    Data.gov (United States)

    National Aeronautics and Space Administration — The field of view required for future missions is much larger than James Webb Space Telescope (JWST). We need to use electrostatic actuation to replace magnetic...

  7. Electrostatic correlations: from plasma to biology

    International Nuclear Information System (INIS)

    Levin, Yan

    2002-01-01

    Electrostatic correlations play an important role in physics, chemistry and biology. In plasmas they result in thermodynamic instability similar to the liquid-gas phase transition of simple molecular fluids. For charged colloidal suspensions the electrostatic correlations are responsible for screening and colloidal charge renormalization. In aqueous solutions containing multivalent counterions they can lead to charge inversion and flocculation. In biological systems the correlations account for the organization of cytoskeleton and the compaction of genetic material. In spite of their ubiquity, the true importance of electrostatic correlations has come to be fully appreciated only quite recently. In this paper, we will review the thermodynamic consequences of electrostatic correlations in a variety of systems ranging from classical plasmas to molecular biology

  8. Electrostatic Spectrometer for Mars Rover Wheel

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop a simple electrostatic spectrometer that can be mounted on the wheels of a Mars rover to continuously and unobtrusively determine the mineral composition and...

  9. The Electrocardiogram as an Example of Electrostatics

    Science.gov (United States)

    Hobbie, Russell K.

    1973-01-01

    Develops a simplified electrostatic model of the heart with conduction within the torso neglected to relate electrocardiogram patterns to the charge distribution within the myocardium. Suggests its application to explanation of Coulomb's law in general physics. (CC)

  10. Highly Tunable Electrothermally and Electrostatically Actuated Resonators

    KAUST Repository

    Hajjaj, Amal Z.; Alcheikh, Nouha; Ramini, Abdallah; Hafiz, Md Abdullah Al; Younis, Mohammad I.

    2016-01-01

    methods, we demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally by passing a dc current through it, and electrostatically by applying a dc polarization voltage between the microbeam

  11. Electrostatically actuated torsional resonant sensors and switches

    KAUST Repository

    Younis, Mohammad I.

    2016-01-01

    Embodiments in accordance of a torsional resonant sensor disclosure is configured to actuate a beam structure using electrostatic actuation with an AC harmonic load (e.g., AC and DC voltage sources) that is activated upon detecting a particular

  12. Quasi-electrostatic waves in dusty plasma

    International Nuclear Information System (INIS)

    Das, A.C.; Goswami, K.S.; Misra, A.K.

    1997-01-01

    Low frequency quasi-electrostatic waves in cold dusty plasma are investigated taking account of liberation and absorption of electrons and ions by the dust and their momentum transfer mechanism. (author)

  13. Review on the Modeling of Electrostatic MEMS

    Directory of Open Access Journals (Sweden)

    Wan-Chun Chuang

    2010-06-01

    Full Text Available Electrostatic-driven microelectromechanical systems devices, in most cases, consist of couplings of such energy domains as electromechanics, optical electricity, thermoelectricity, and electromagnetism. Their nonlinear working state makes their analysis complex and complicated. This article introduces the physical model of pull-in voltage, dynamic characteristic analysis, air damping effect, reliability, numerical modeling method, and application of electrostatic-driven MEMS devices.

  14. Nonlinear Electrostatic Wave Equations for Magnetized Plasmas

    DEFF Research Database (Denmark)

    Dysthe, K.B.; Mjølhus, E.; Pécseli, Hans

    1984-01-01

    The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed.......The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed....

  15. A Direct Driver for Electrostatic Transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2014-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes a power stage suitable for driving an electrostatic transducer under biasing. Measurement results of a ±400 V prototype amplifier are shown. THD below 1% is reported....

  16. Electrostatic Levitation Furnace for the ISS

    Science.gov (United States)

    Murakami, Keiji; Koshikawa, Naokiyo; Shibasaki, Kohichi; Ishikawa, Takehiko; Okada, Junpei; Takada, Tetsuya; Arai, Tatsuya; Fujino, Naoki; Yamaura, Yukiko

    2012-01-01

    JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedule

  17. High-energy capacitance electrostatic micromotors

    Science.gov (United States)

    Baginsky, I. L.; Kostsov, E. G.

    2003-03-01

    The design and parameters of a new electrostatic micromotor with high energy output are described. The motor is created by means of microelectronic technology. Its operation is based on the electromechanic energy conversion during the electrostatic rolling of the metallic films (petals) on the ferroelectric film surface. The mathematical simulation of the main characteristics of the rolling process is carried out. The experimentally measured parameters of the petal step micromotors are shown. The motor operation and its efficiency are investigated.

  18. Energy Balance in an Electrostatic Accelerator

    OpenAIRE

    Zolotorev, Max S.; McDonald, Kirk T.

    2000-01-01

    The principle of an electrostatic accelerator is that when a charge e escapes from a conducting plane that supports a uniform electric field of strength E_0, then the charge gains energy e E_0 d as it moves distance d from the plane. Where does this energy come from? We that the mechanical energy gain of the electron is balanced by the decrease in the electrostatic field energy of the system.

  19. Optics Elements for Modeling Electrostatic Lenses and Accelerator Components: III. Electrostatic Deflectors

    International Nuclear Information System (INIS)

    Brown, T.A.; Gillespie, G.H.

    1999-01-01

    Ion-beam optics models for simulating electrostatic prisms (deflectors) of different geometries have been developed for the computer code TRACE 3-D. TRACE 3-D is an envelope (matrix) code, which includes a linear space charge model, that was originally developed to model bunched beams in magnetic transport systems and radiofrequency (RF) accelerators. Several new optical models for a number of electrostatic lenses and accelerator columns have been developed recently that allow the code to be used for modeling beamlines and accelerators with electrostatic components. The new models include a number of options for: (1) Einzel lenses, (2) accelerator columns, (3) electrostatic prisms, and (4) electrostatic quadrupoles. A prescription for setting up the initial beam appropriate to modeling 2-D (continuous) beams has also been developed. The models for electrostatic prisms are described in this paper. The electrostatic prism model options allow the modeling of cylindrical, spherical, and toroidal electrostatic deflectors. The application of these models in the development of ion-beam transport systems is illustrated through the modeling of a spherical electrostatic analyzer as a component of the new low energy beamline at CAMS

  20. COMPOSITION OF HERB AND SEED OIL AND ANTIMICROBIAL ACTIVITY OF THE ESSENTIAL OIL OF TWO VARIETIES OF OCIMUM BASILICUM HARVESTED AT SHORT TIME INTERVALS

    Directory of Open Access Journals (Sweden)

    Pandu Sastry KAKARAPARTHI

    2015-12-01

    Full Text Available An experiment was conducted to study the changes in the chemical composition of the essential oil of two varieties of Ocimum basilicum over a period of six months at short harvest intervals for two crop seasons. In variety Vikarsudha, GC/MS analysis revealed the presence of eighteen essential oil constituents. Linalool (23.5­40.1% and 22.8­33.7% and methyl chavicol (25.4­51.9% and 40.0­52.7% were the major constituents in main and ratoon crops. Similarly, in variety Kuhmohak GC/MS analysis revealed the presence of linalool (19.2­25.4 % and 16.1­31.3% and methyl chavicol (34.7­53.4% and 39.4­59.2% in large quantities in main and ratoon crops, respectively. β myrcene, limonene, 1,8 cineole, ocimene, camphor, terpinen-4-ol, bornyl acetate, eugenol, methyl eugenol, β elemene, β caryophyllene, α humulene, γ Cadinene and cadinol were present in small quantities. Results pertaining to the zone of inhibition in the antimicrobial activity of essential oil indicated that Chromobacterium violaceum is more sensitive compared to Staphylococcus aureus. Among the fungal strains Aspergillus niger was found to be more sensitive. GC-MS analysis of the fixed oils obtained from the seeds in the ratoon crop revealed the presence of unsaturated and saturated fatty acids. The unsaturated fatty acids averaged 89% consisting of α-linolenic (49.3%­52.4%, linoleic (23.4%­26.0%, and oleic (10.3%­12.3% acids. The most abundant saturated fatty acids were palmitic and stearic acids.

  1. PCE: web tools to compute protein continuum electrostatics

    Science.gov (United States)

    Miteva, Maria A.; Tufféry, Pierre; Villoutreix, Bruno O.

    2005-01-01

    PCE (protein continuum electrostatics) is an online service for protein electrostatic computations presently based on the MEAD (macroscopic electrostatics with atomic detail) package initially developed by D. Bashford [(2004) Front Biosci., 9, 1082–1099]. This computer method uses a macroscopic electrostatic model for the calculation of protein electrostatic properties, such as pKa values of titratable groups and electrostatic potentials. The MEAD package generates electrostatic energies via finite difference solution to the Poisson–Boltzmann equation. Users submit a PDB file and PCE returns potentials and pKa values as well as color (static or animated) figures displaying electrostatic potentials mapped on the molecular surface. This service is intended to facilitate electrostatics analyses of proteins and thereby broaden the accessibility to continuum electrostatics to the biological community. PCE can be accessed at . PMID:15980492

  2. Study of a condition for the mode conversion from purely perpendicular electrostatic waves to electromagnetic waves

    Energy Technology Data Exchange (ETDEWEB)

    Kalaee, Mohammad Javad, E-mail: mjkalaee@ut.ac.ir [Space Physics Group, Institute of Geophysics, University of Tehran (Iran, Islamic Republic of); Katoh, Yuto, E-mail: yuto@stpp.gp.tohoku.ac.jp [Department of Geophysics, Graduate School of Science, Tohoku University (Japan)

    2016-07-15

    One of the mechanisms for generating electromagnetic plasma waves (Z-mode and LO-mode) is mode conversion from electrostatic waves into electromagnetic waves in inhomogeneous plasma. Herein, we study a condition required for mode conversion of electrostatic waves propagating purely perpendicular to the ambient magnetic field, by numerically solving the full dispersion relation. An approximate model is derived describing the coupling between electrostatic waves (hot plasma Bernstein mode) and Z-mode waves at the upper hybrid frequency. The model is used to study conditions required for mode conversion from electrostatic waves (electrostatic electron cyclotron harmonic waves, including Bernstein mode) into electromagnetic plasma waves (LO-mode). It is shown that for mode conversion to occur in inhomogeneous plasma, the angle between the boundary surface and the magnetic field vector should be within a specific range. The range of the angle depends on the norm of the k vector of waves at the site of mode conversion in the inhomogeneous region. The present study reveals that inhomogeneity alone is not a sufficient condition for mode conversion from electrostatic waves to electromagnetic plasma waves and that the angle between the magnetic field and the density gradient plays an important role in the conversion process.

  3. The first step in layer-by-layer deposition: Electrostatics and/or non-electrostatics?

    NARCIS (Netherlands)

    Lyklema, J.; Deschênes, L.

    2011-01-01

    A critical discussion is presented on the properties and prerequisites of adsorbed polyelectrolytes that have to function as substrates for further layer-by-layer deposition. The central theme is discriminating between the roles of electrostatic and non-electrostatic interactions. In order to

  4. Electrostatic and electromagnetic instabilities associated with electrostatic shocks: Two-dimensional particle-in-cell simulation

    International Nuclear Information System (INIS)

    Kato, Tsunehiko N.; Takabe, Hideaki

    2010-01-01

    A two-dimensional electromagnetic particle-in-cell simulation with the realistic ion-to-electron mass ratio of 1836 is carried out to investigate the electrostatic collisionless shocks in relatively high-speed (∼3000 km s -1 ) plasma flows and also the influence of both electrostatic and electromagnetic instabilities, which can develop around the shocks, on the shock dynamics. It is shown that the electrostatic ion-ion instability can develop in front of the shocks, where the plasma is under counterstreaming condition, with highly oblique wave vectors as was shown previously. The electrostatic potential generated by the electrostatic ion-ion instability propagating obliquely to the shock surface becomes comparable with the shock potential and finally the shock structure is destroyed. It is also shown that in front of the shock the beam-Weibel instability gradually grows as well, consequently suggesting that the magnetic field generated by the beam-Weibel instability becomes important in long-term evolution of the shock and the Weibel-mediated shock forms long after the electrostatic shock vanished. It is also observed that the secondary electrostatic shock forms in the reflected ions in front of the primary electrostatic shock.

  5. A Time Interval of More Than 18 Months Between a Pregnancy and a Roux-en-Y Gastric Bypass Increases the Risk of Iron Deficiency and Anaemia in Pregnancy

    DEFF Research Database (Denmark)

    Crusell, Mie Korslund Wiinblad; Nilas, Lisbeth; Svare, Jens

    2016-01-01

    OBJECTIVE: The aim of the study is to explore the impact of time between Roux-en-Y gastric bypass (RYGB) and pregnancy on obstetrical outcome and nutritional derangements. METHODS: In a retrospective cross-sectional study of pregnant women admitted for antenatal care at two tertiary hospitals, we...... examined 153 women with RYGB and a singleton pregnancy of at least 24 weeks. The women were stratified according to a pregnancy nutritional parameters and glycated haemoglobin 1Ac (HbA1c) in second and third trimester...... of adverse pregnancy outcome or birth weight between the two groups. CONCLUSION: A long surgery-to-pregnancy time interval after a RYGB increases the risk of iron deficiency anaemia but not of other nutritional deficits. Time interval does not seem to have an adverse effect on the obstetrical outcome...

  6. A Time Interval of More Than 18 Months Between a Pregnancy and a Roux-en-Y Gastric Bypass Increases the Risk of Iron Deficiency and Anaemia in Pregnancy.

    Science.gov (United States)

    Crusell, Mie; Nilas, Lisbeth; Svare, Jens; Lauenborg, Jeannet

    2016-10-01

    The aim of the study is to explore the impact of time between Roux-en-Y gastric bypass (RYGB) and pregnancy on obstetrical outcome and nutritional derangements. In a retrospective cross-sectional study of pregnant women admitted for antenatal care at two tertiary hospitals, we examined 153 women with RYGB and a singleton pregnancy of at least 24 weeks. The women were stratified according to a pregnancy pregnancy, gestational hypertension, length of pregnancy, mode of delivery and foetal birth weight. The two groups were comparable regarding age, parity and prepregnancy body mass index. The frequency of iron deficiency anaemia (ferritin pregnancy outcome or birth weight between the two groups. A long surgery-to-pregnancy time interval after a RYGB increases the risk of iron deficiency anaemia but not of other nutritional deficits. Time interval does not seem to have an adverse effect on the obstetrical outcome, including intrauterine growth restriction. Specific attention is needed on iron deficit with increasing surgery-to-pregnancy time interval.

  7. Field distribution in a coaxial electrostatic wiggler

    Directory of Open Access Journals (Sweden)

    Shi-Chang Zhang

    2010-09-01

    Full Text Available The field distribution in a coaxial electrostatic wiggler corresponds to the special solution of a Laplace equation in a cylindrical coordinate system with a boundary value problem of sinusoidal ripples. This paper is devoted to the physical and mathematical treatment for an analytical solution of the field distribution in the coaxial electrostatic wiggler. The explicit expression of the solution indicates that the field distribution in the coaxial electrostatic wiggler varies according to a periodic function in the longitudinal direction, and is related to the first and second kinds of modified Bessel functions in the radial direction, respectively. Comparison shows excellent agreement between the analytical formula and the computer simulation technology (CST results. The physical application of the considered system and its analytical solution are discussed.

  8. Electrostatic coating technologies for food processing.

    Science.gov (United States)

    Barringer, Sheryl A; Sumonsiri, Nutsuda

    2015-01-01

    The application of electrostatics in both powder and liquid coating can improve the quality of food, such as its appearance, aroma, taste, and shelf life. Coatings can be found most commonly in the snack food industry, as well as in confectionery, bakery, meat and cheese processing. In electrostatic powder coating, the most important factors influencing coating quality are powder particle size, density, flowability, charge, and resistivity, as well as the surface properties and characteristics of the target. The most important factors during electrostatic liquid coating, also known as electrohydrodynamic coating, include applied voltage and electrical resistivity and viscosity of the liquid. A good understanding of these factors is needed for the design of optimal coating systems for food processing.

  9. Acoustic effects of single electrostatic discharges

    International Nuclear Information System (INIS)

    Orzech, Łukasz

    2015-01-01

    Electric discharges, depending on their character, can emit different types of energy, resulting in different effects. Single electrostatic discharges besides generation of electromagnetic pulses are also the source of N acoustic waves. Their specified parameters depending on amount of discharging charge enable determination of value of released charge in a function of acoustic descriptor (e.g. acoustic pressure). Presented approach is the basics of acoustic method for measurement of single electrostatic discharges, enabling direct and contactless measurement of value of charge released during ESD. Method for measurement of acoustic effect of impact of a single electrostatic discharge on the environment in a form of pressure shock wave and examples of acoustic descriptors in a form of equation Q=f(p a ) are described. The properties of measuring system as well as the results of regression static analyses used to determine the described relationships are analysed in details. (paper)

  10. Electrostatic micromotor based on ferroelectric ceramics

    Science.gov (United States)

    Baginsky, I. L.; Kostsov, E. G.

    2004-11-01

    A new electrostatic micromotor is described that utilizes the electromechanical energy conversion principle earlier described by the authors. The electromechanical energy conversion is based on reversible electrostatic rolling of thin metallic films (petals) on a ferroelectric surface. The motor's active media are layers of ferroelectric ceramics (about 100 µm in thickness). The characteristics of the electrostatic rolling of the petals on different ceramic surfaces are studied, as well as the dynamic characteristics of the micromotors. It is shown that the use of antiferroelectric material allows one to reach a specific energy capacitance comparable to that of the micromotors based on ferroelectric films and to achieve a specific power of 30-300 µW mm-2.

  11. Electrostatic Deposition of Large-Surface Graphene

    Directory of Open Access Journals (Sweden)

    Charles Trudeau

    2018-01-01

    Full Text Available This work describes a method for electrostatic deposition of graphene over a large area using controlled electrostatic exfoliation from a Highly Ordered Pyrolytic Graphite (HOPG block. Deposition over 130 × 130 µm2 with 96% coverage is achieved, which contrasts with sporadic micro-scale depositions of graphene with little control from previous works on electrostatic deposition. The deposition results are studied by Raman micro-spectroscopy and hyperspectral analysis using large fields of view to allow for the characterization of the whole deposition area. Results confirm that laser pre-patterning of the HOPG block prior to cleaving generates anchor points favoring a more homogeneous and defect-free HOPG surface, yielding larger and more uniform graphene depositions. We also demonstrate that a second patterning of the HOPG block just before exfoliation can yield features with precisely controlled geometries.

  12. Electrostatic dry powder prepregging of carbon fiber

    Science.gov (United States)

    Throne, James L.; Sohn, Min-Seok

    1990-01-01

    Ultrafine, 5-10 micron polymer-matrix resin powders are directly applied to carbon fiber tows by passing then in an air or nitrogen stream through an electrostatic potential; the particles thus charged will strongly adhere to grounded carbon fibers, and can be subsequently fused to the fiber in a continuously-fed radiant oven. This electrostatic technique derived significant end-use mechanical property advantages from the obviation of solvents, binders, and other adulterants. Additional matrix resins used to produce prepregs to date have been PMR-15, Torlon 40000, and LaRC TPI.

  13. Histidine in Continuum Electrostatics Protonation State Calculations

    Science.gov (United States)

    Couch, Vernon; Stuchebruckhov, Alexei

    2014-01-01

    A modification to the standard continuum electrostatics approach to calculate protein pKas which allows for the decoupling of histidine tautomers within a two state model is presented. Histidine with four intrinsically coupled protonation states cannot be easily incorporated into a two state formalism because the interaction between the two protonatable sites of the imidazole ring is not purely electrostatic. The presented treatment, based on a single approximation of the interrelation between histidine’s charge states, allows for a natural separation of the two protonatable sites associated with the imidazole ring as well as the inclusion of all protonation states within the calculation. PMID:22072521

  14. Design of an electrostatic magnetic quadrupole accelerator

    International Nuclear Information System (INIS)

    Mizuno, M.; Ohara, Y.

    1993-01-01

    A new type of electrostatic acceleration system, electrostatic magnetic quadrupole (ESMQ) acceleration system, is proposed for efficient acceleration of negative ion beams. In this system, permanent magnets are buried in the acceleration electrodes so as to produce a quadrupole magnetic field in the electrode aperture region. Envelope simulation indicates that the quadrupole field can deflect electrons stripped from the negative ions. Beam envelope simulations for deuterium ions and electrons have been carried out using the beam envelope code TRACE. Electrons are largely divergent and most appear likely to hit downstream electrodes. Furthermore, maximum beam divergence of the deuterium ions is reduced to the focusing effect of the quadrupole magnetic field

  15. Electrostatic air filters generated by electric fields

    International Nuclear Information System (INIS)

    Bergman, W.; Biermann, A.H.; Hebard, H.D.; Lum, B.Y.; Kuhl, W.D.

    1981-01-01

    This paper presents theoretical and experimental findings on fibrous filters converted to electrostatic operation by a nonionizing electric field. Compared to a conventional fibrous filter, the electrostatic filter has a higher efficiency and a longer, useful life. The increased efficiency is attributed to a time independent attraction between polarized fibers and charged, polarized particles and a time dependent attraction between charged fibers and charged, polarized particles. The charge on the fibers results from a dynamic process of charge accumulation due to the particle deposits and a charge dissipation due to the fiber conductivity

  16. The contribution of the electrostatic proximity force to atomic force microscopy with insulators

    International Nuclear Information System (INIS)

    Stanley Czarnecki, W.; Schein, L.B.

    2005-01-01

    Measurements, using atomic force microscopy, of the force and force derivative on a charged insulating micron sized sphere as a function of gap between the sphere and a conductive plane have revealed attractive forces at finite gaps that are larger than predicted by either van der Waals or conventional electrostatic forces. We suggest that these observations may be due to an electrostatic force that we have identified theoretically and call the proximity force. This proximity force is due to the discrete charges on the surface of the sphere in close proximity to the plane

  17. The contribution of the electrostatic proximity force to atomic force microscopy with insulators

    Energy Technology Data Exchange (ETDEWEB)

    Stanley Czarnecki, W. [Aetas Technology Corporation, P.O. Box 53398, Irvine, CA 92619-3398 (United States); IBM Corporation, 5600 Cottle Rd., Building 13, San Jose, CA 95193 (United States); Schein, L.B. [Aetas Technology Corporation, P.O. Box 53398, Irvine, CA 92619-3398 (United States)]. E-mail: schein@prodigy.net

    2005-05-16

    Measurements, using atomic force microscopy, of the force and force derivative on a charged insulating micron sized sphere as a function of gap between the sphere and a conductive plane have revealed attractive forces at finite gaps that are larger than predicted by either van der Waals or conventional electrostatic forces. We suggest that these observations may be due to an electrostatic force that we have identified theoretically and call the proximity force. This proximity force is due to the discrete charges on the surface of the sphere in close proximity to the plane.

  18. Split-illumination electron holography for improved evaluation of electrostatic potential associated with electrophotography

    Energy Technology Data Exchange (ETDEWEB)

    Tanigaki, Toshiaki, E-mail: tanigaki-toshiaki@riken.jp; Aizawa, Shinji; Soon Park, Hyun [Center for Emergent Matter Science (CEMS), RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Sato, Kuniaki; Akase, Zentaro [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Matsuda, Tsuyoshi [Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan); Murakami, Yasukazu; Shindo, Daisuke [Center for Emergent Matter Science (CEMS), RIKEN, Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577 (Japan); Kawase, Hiromitsu [Product Environment Technology Development Department, Environment and Energy Technology Development Center R and D Group, RICOH Co., Ltd., Shinei-cho, Tsuzuki-ku, Yokohama, Kanagawa 224-0035 (Japan)

    2014-03-31

    Precise evaluation of the electrostatic potential distributions of and around samples with multiple charges using electron holography has long been a problem due to unknown perturbation of the reference wave. Here, we report the first practical application of split-illumination electron holography (SIEH) to tackle this problem. This method enables the use of a non-perturbed reference wave distant from the sample. SIEH revealed the electrostatic potential distributions at interfaces of the charged particles used for development in electrophotography and should lead to dramatic improvements in electrophotography.

  19. Split-illumination electron holography for improved evaluation of electrostatic potential associated with electrophotography

    International Nuclear Information System (INIS)

    Tanigaki, Toshiaki; Aizawa, Shinji; Soon Park, Hyun; Sato, Kuniaki; Akase, Zentaro; Matsuda, Tsuyoshi; Murakami, Yasukazu; Shindo, Daisuke; Kawase, Hiromitsu

    2014-01-01

    Precise evaluation of the electrostatic potential distributions of and around samples with multiple charges using electron holography has long been a problem due to unknown perturbation of the reference wave. Here, we report the first practical application of split-illumination electron holography (SIEH) to tackle this problem. This method enables the use of a non-perturbed reference wave distant from the sample. SIEH revealed the electrostatic potential distributions at interfaces of the charged particles used for development in electrophotography and should lead to dramatic improvements in electrophotography

  20. Long-pore Electrostatics in Inward-rectifier Potassium Channels

    Science.gov (United States)

    Robertson, Janice L.; Palmer, Lawrence G.; Roux, Benoît

    2008-01-01

    Inward-rectifier potassium (Kir) channels differ from the canonical K+ channel structure in that they possess a long extended pore (∼85 Å) for ion conduction that reaches deeply into the cytoplasm. This unique structural feature is presumably involved in regulating functional properties specific to Kir channels, such as conductance, rectification block, and ligand-dependent gating. To elucidate the underpinnings of these functional roles, we examine the electrostatics of an ion along this extended pore. Homology models are constructed based on the open-state model of KirBac1.1 for four mammalian Kir channels: Kir1.1/ROMK, Kir2.1/IRK, Kir3.1/GIRK, and Kir6.2/KATP. By solving the Poisson-Boltzmann equation, the electrostatic free energy of a K+ ion is determined along each pore, revealing that mammalian Kir channels provide a favorable environment for cations and suggesting the existence of high-density regions in the cytoplasmic domain and cavity. The contribution from the reaction field (the self-energy arising from the dielectric polarization induced by the ion's charge in the complex geometry of the pore) is unfavorable inside the long pore. However, this is well compensated by the electrostatic interaction with the static field arising from the protein charges and shielded by the dielectric surrounding. Decomposition of the static field provides a list of residues that display remarkable correspondence with existing mutagenesis data identifying amino acids that affect conduction and rectification. Many of these residues demonstrate interactions with the ion over long distances, up to 40 Å, suggesting that mutations potentially affect ion or blocker energetics over the entire pore. These results provide a foundation for understanding ion interactions in Kir channels and extend to the study of ion permeation, block, and gating in long, cation-specific pores. PMID:19001143

  1. Resolving beam transport problems in electrostatic accelerators

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    A review is given of problem areas in beam transmission which are frequently encountered during the design, operation and upgrading of electrostatic accelerators. Examples are provided of analytic procedures that clarify accelerator ion optics and lead to more effective beam transport. Suggestions are made for evaluating accelerator design with the goal of improved performance

  2. Efficient optimization of electrostatic interactions between biomolecules.

    Energy Technology Data Exchange (ETDEWEB)

    Bardhan, J. P.; Altman, M. D.; White, J. K.; Tidor, B.; Mathematics and Computer Science; MIT

    2007-01-01

    We present a PDE-constrained approach to optimizing the electrostatic interactions between two biomolecules. These interactions play important roles in the determination of binding affinity and specificity, and are therefore of significant interest when designing a ligand molecule to bind tightly to a receptor. Using a popular continuum model and physically reasonable assumptions, the electrostatic component of the binding free energy is a convex, quadratic function of the ligand charge distribution. Traditional optimization methods require exhaustive pre-computation, and the expense has precluded a full exploration of the promise of electrostatic optimization in biomolecule analysis and design. In this paper we describe an approach in which the electrostatic simulations and optimization problem are solved simultaneously; unlike many PDE- constrained optimization frameworks, the proposed method does not incorporate the PDE as a set of equality constraints. This co-optimization approach can be used by itself to solve unconstrained problems or those with linear equality constraints, or in conjunction with primal-dual interior point methods to solve problems with inequality constraints. Model problems demonstrate that the co-optimization method is computationally efficient and can be used to solve realistic problems.

  3. Collapse of Electrostatic Waves in Magnetoplasmas

    DEFF Research Database (Denmark)

    Shukla, P. K.; Yu, M. Y.; Juul Rasmussen, Jens

    1984-01-01

    The two-fluid model is employed to investigate the collapse of electrostatic waves in magnetized plasmas. It is found that nonlinear interaction of ion cyclotron, upper-, and lower-hybrid waves with adiabatic particle motion along the external magnetic field can cause wave-field collapse....

  4. Dynamical Aspects of Electrostatic Double Layers

    DEFF Research Database (Denmark)

    Raadu, M.A.; Juul Rasmussen, J.

    1988-01-01

    Electrostatic double layers have been proposed as an acceleration mechanism in solar flares and other astrophysical objects. They have been extensively studied in the laboratory and by means of computer simulations. The theory of steady-state double layers implies several existence criteria...

  5. Resolving beam transport problems in electrostatic accelerators

    International Nuclear Information System (INIS)

    Larson, J.D.

    1977-01-01

    This paper reviews problem areas in beam transmission which are frequently encountered during the design, operation and upgrading of electrostatic accelerators. Examples are provided of analytic procedures that clarify accelerator ion optics and lead to more effective beam transport. Suggestions are made for evaluating accelerator design with the goal of improved performance

  6. Electrostatics of Pharmaceutical Aerosols for Pulmonary Delivery.

    Science.gov (United States)

    Lip Kwok, Philip Chi

    2015-01-01

    This paper provides a review on key research findings in the rapidly developing area of pharmaceutical aerosol electrostatics. Solids and liquids can become charged without electric fields, the former by contact or friction and the latter by flowing or spraying. Therefore, charged particles and droplets carrying net charges are produced from pharmaceutical inhalers (e.g. dry powder inhalers, metered dose inhalers, and nebulisers) due to the mechanical processes involved in aerosolisation. The charging depends on many physicochemical factors, such as formulation composition, solid state properties, inhaler material and design, and relative humidity. In silico, in vitro, and limited in vivo studies have shown that electrostatic charges may potentially influence particle deposition in the airways. However, the evidence is not yet conclusive. Furthermore, there are currently no regulatory requirements on the characterisation and control of the electrostatic properties of inhaled formulations. Besides the need for further investigations on the relationship between physicochemical factors and charging characteristics of the aerosols, controlled and detailed in vivo studies are also required to confirm whether charges can affect particle deposition in the airways. Since pharmaceutical aerosol electrostatics is a relatively new research area, much remains to be explored. Thus there is certainly potential for development. New findings in the future may contribute to the advancement of pharmaceutical aerosol formulations and respiratory drug delivery.

  7. Electrostatics of a Family of Conducting Toroids

    Science.gov (United States)

    Lekner, John

    2009-01-01

    An exact solution is found for the electrostatic potential of a family of conducting charged toroids. The toroids are characterized by two lengths "a" and "b", with "a" greater than or equal to "2b". They are closed, with no hole in the "doughnut". The results are obtained by considering the potential of two equal charges, displaced from the…

  8. The Electrostatic Environments of Mars: Atmospheric Discharges

    Science.gov (United States)

    Calle, Carlos I.; Mackey, Paul J.; Johansen, Michael R.; Hogue, Michael D.; Phillips, James, III; Cox, Rachel E.

    2016-01-01

    The electrostatic environment on Mars is controlled by its ever present atmospheric dust. Dust devils and dust storms tribocharge this dust. Theoretical studies predict that lightning and/or glow discharges should be present on Mars, but none have been directly observed. Experiments are planned to shed light on this issue.

  9. Surface charge measurement using an electrostatic probe

    DEFF Research Database (Denmark)

    Crichton, George C; McAllister, Iain Wilson

    1998-01-01

    During the 1960s, the first measurements of charge on dielectric surfaces using simple electrostatic probes were reported. However it is only within the last 10 years that a proper understanding of the probe response has been developed. This situation arose as a consequence of the earlier studies...

  10. The electrostatic interaction between interfacial colloidal particles

    Science.gov (United States)

    Hurd, A. J.

    1985-11-01

    The electrostatic interaction between charged, colloidal particles trapped at an air-water interface is considered using linearised Poisson-Boltzmann results for point particles. In addition to the expected screened-Coulomb contribution, which decays exponentially, an algebraic dipole-dipole interaction occurs that may account for long-range interactions in interfacial colloidal systems.

  11. Electrostatic-Dipole (ED) Fusion Confinement Studies

    Science.gov (United States)

    Miley, George H.; Shrestha, Prajakti J.; Yang, Yang; Thomas, Robert

    2004-11-01

    The Electrostatic-Dipole (ED) concept significantly differs from a "pure" dipole confinement device [1] in that the charged particles are preferentially confined to the high-pressure region interior of the dipole coil by the assistance of a surrounding spherical electrostatic grid. In present ED experiments, a current carrying coil is embedded inside the grid of an IEC such as to produce a magnetic dipole field. Charged particles are injected axisymmetrically from an ion gun (or duo-plasmatron) into the center of the ED confinement grid/dipole ring where they oscillate along the magnetic field lines and pass the peak field region at the center of the dipole region. As particles begin accelerating away from the center region towards the outer electrostatic grid region, they encounter a strong electrostatic potential (order of 10's of kilovolts) retarding force. The particles then decelerate, reverse direction and re-enter the dipole field region where again magnetic confinement dominates. This process continues, emulating a complex harmonic oscillator motion. The resulting pressure profile averaged over the field curvature offers good plasma stability in the ED configuration. The basic concept and results from preliminary experiments will be described. [1] M.E. Mauel, et al. "Dipole Equilibrium and Stability," 18th IAEA Conference of Plasma Phys. and Control. Nuclear Fusion, Varenna, Italy 2000, IAEA-F1-CN-70/TH

  12. Electrostatic fuel conditioning of internal combustion engines

    Science.gov (United States)

    Gold, P. I.

    1982-01-01

    Diesel engines were tested to determine if they are influenced by the presence of electrostatic and magnetic fields. Field forces were applied in a variety of configurations including pretreatment of the fuel and air, however, no affect on engine performance was observed.

  13. Electrostatic MEMS devices with high reliability

    Science.gov (United States)

    Goldsmith, Charles L; Auciello, Orlando H; Sumant, Anirudha V; Mancini, Derrick C; Gudeman, Chris; Sampath, Suresh; Carlilse, John A; Carpick, Robert W; Hwang, James

    2015-02-24

    The present invention provides for an electrostatic microelectromechanical (MEMS) device comprising a dielectric layer separating a first conductor and a second conductor. The first conductor is moveable towards the second conductor, when a voltage is applied to the MEMS device. The dielectric layer recovers from dielectric charging failure almost immediately upon removal of the voltage from the MEMS device.

  14. Electrostatic nanopatterning of PMMA by AFM charge writing for directed nano-assembly

    International Nuclear Information System (INIS)

    Ressier, L; Nader, V Le

    2008-01-01

    Electrostatic nanopatterning of poly(methylmethacrylate) (PMMA) thin films by atomic force microscopy (AFM) charge writing was investigated using Kelvin force microscopy (KFM). The lateral size of the electrostatic patterns and the amount of injected charges are closely correlated and can be controlled by the height of the voltage pulses applied to the AFM tip and the tip-sample separation during the writing process. Charge retention measurements show that PMMA has excellent charge storage properties in air under relative humidities from 1% to 60% and withstands immersion in ultra-pure water. This study thus reveals that PMMA is a very promising electret to create efficient electrostatic nanopatterns for directed self-assembly of nanoscale objects, including the broad range of colloidal particles or molecules in aqueous solutions

  15. Response of an electrostatic probe for a right cylindrical spacer

    DEFF Research Database (Denmark)

    Rerup, T; Crichton, George C; McAllister, Iain Wilson

    1994-01-01

    During the last decade many experimental studies of surface charge phenomena have been undertaken employing right cylindrical spacers. Measurement of the surface charge was performed using small electrostatic field probes to scan across the dielectric surface. Charges are electrostatically induced...

  16. Fabrication and characterization of an electrostatic contraction beams micromotor

    NARCIS (Netherlands)

    Sarajlic, Edin; Berenschot, Johan W.; Tas, Niels Roelof; Fujita, H.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2006-01-01

    We report on fabrication and experimental characterization of an electrostatic contraction beams motor that exhibits both reliable operation and high performance haracteristics. This electrostatic linear stepper micromotor is fabricated in a single polysilicon layer combining vertical trench

  17. Nonlinear Dynamics of Carbon Nanotubes Under Large Electrostatic Force

    KAUST Repository

    Xu, Tiantian; Younis, Mohammad I.

    2015-01-01

    Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction

  18. A Novel Electrostatic/Microstructured Adhesive with Dust Mitigation Capabilities

    Data.gov (United States)

    National Aeronautics and Space Administration — This work will develop a novel electrostatic/gecko-like adhesive that will demonstrate an order-of-magnitude improvement of electrostatic adhesion pressure coupled...

  19. Charging and absorption characteristics of small particulates under alternative and electrostatic voltages in an electrostatic precipitator

    International Nuclear Information System (INIS)

    Jiang Xue-Dong; Xu He; Wang Xin

    2014-01-01

    The charge quantity of small particulates such as PM2.5 plays a key role in the collection efficiency of an electrostatic precipitator (ESP). Under a single electrostatic voltage, it is difficult to charge and absorb small particulates. A new method of superimposing an alternative voltage on the electrostatic voltage is provided in this paper. Characteristics of small particulates are analyzed under alternative and electrostatic voltages. It is demonstrated that an alternative voltage can significantly improve the collection efficiency in three aspects: preventing anti-corona, increasing the charge quantity of small particulates, and increasing the median particulate size by electric agglomeration. In addition, practical usage with the superposition of alternative voltage is provided, and the results are in agreement with the theoretical analysis. (physics of gases, plasmas, and electric discharges)

  20. A Study of Electrostatic Charge on Insulating Film by Electrostatic Force Microscopy

    International Nuclear Information System (INIS)

    Kikunaga, K; Toosaka, K; Kamohara, T; Sakai, K; Nonaka, K

    2011-01-01

    Electrostatic charge properties on polypropylene film have been characterized by atomic force microscopy and electrostatic force microscopy. The measurements have been carried out after the polypropylene film was electrified by contact and separation process in an atmosphere of controlled humidity. The negative and positive charge in concave surface has been observed. The correlation between concave surface and charge position suggests that the electrostatic charges could be caused by localized contact. On the other hand, positive charge on a flat surface has been observed. The absence of a relationship between surface profile and charge position suggests that the electrostatic charge should be caused by discharge during the separation process. The spatial migration of other positive charges through surface roughness has been observed. The results suggest that there could be some electron traps on the surface roughness and some potentials on the polypropylene film.

  1. Perceptions of Time and Long Time Intervals

    Energy Technology Data Exchange (ETDEWEB)

    Drottz-Sjoeberg, Britt-Marie [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Psychology

    2006-09-15

    There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations' general responsibility for future consequences reached from 3.4 to 5.9 generations, estimated to about 80-150 years. These very concrete figures and the presented risk estimates do not seem to fit the strength in the often voiced responsibilities of our generations unless these are consistent with a very restricted definition of 'future generations'.

  2. First Passage Time Intervals of Gaussian Processes

    Science.gov (United States)

    Perez, Hector; Kawabata, Tsutomu; Mimaki, Tadashi

    1987-08-01

    The first passage time problem of a stationary Guassian process is theretically and experimentally studied. Renewal functions are derived for a time-dependent boundary and numerically calculated for a Gaussian process having a seventh-order Butterworth spectrum. The results show a multipeak property not only for the constant boundary but also for a linearly increasing boundary. The first passage time distribution densities were experimentally determined for a constant boundary. The renewal functions were shown to be a fairly good approximation to the distribution density over a limited range.

  3. Perceptions of Time and Long Time Intervals

    International Nuclear Information System (INIS)

    Drottz-Sjoeberg, Britt-Marie

    2006-01-01

    There are certainly many perspectives presented in the literature on time and time perception. This contribution has focused on perceptions of the time frames related to risk and danger of radiation from a planned Swedish repository for spent nuclear fuel. Respondents from two municipalities judged SSI's reviews of the entrepreneur's plans and work of high importance, and more important the closer to our time the estimate was given. Similarly were the consequences of potential leakage from a repository perceived as more serious the closer it would be to our time. Judgements of risks related to the storage of spent nuclear fuel were moderately large on the used measurement scales. Experts are experts because they have more knowledge, and in this context they underlined e.g. the importance of reviews of the radiation situation of time periods up to 100,000 years. It was of interest to note that 55% of the respondents from the municipalities did not believe that the future repository would leak radioactivity. They were much more pessimistic with respect to world politics, i.e. a new world war. However, with respect to the seriousness of the consequences given a leakage from the repository, the public group consistently gave high risk estimates, often significantly higher than those of the expert group. The underestimations of time estimates, as seen in the tasks of pinpointing historic events, provide examples of the difficulty of making estimations involving long times. Similar results showed that thinking of 'the future' most often involved about 30 years. On average, people reported memories of about 2.5 generations back in time, and emotional relationships stretching approximately 2.5 generations into the future; 94% of the responses, with respect to how many future generations one had an emotional relationship, were given in the range of 1-5 generations. Similarly, Svenson and Nilsson found the opinion that the current generations' general responsibility for future consequences reached from 3.4 to 5.9 generations, estimated to about 80-150 years. These very concrete figures and the presented risk estimates do not seem to fit the strength in the often voiced responsibilities of our generations unless these are consistent with a very restricted definition of 'future generations'

  4. Electrostatic Charging and Particle Interactions in Microscopic Insulating Grains

    Science.gov (United States)

    Lee, Victor

    In this thesis, we experimentally investigate the electrostatic charging as well as the particle interactions in microscopic insulating grains. First, by tracking individual grains accelerated in an electric field, we quantitatively demonstrate that tribocharging of same-material grains depends on particle size. Large grains tend to charge positively, and small ones tend to charge negatively. Theories based on the transfer of trapped electrons can explain this tendency but have not been validated. Here we show that the number of trapped electrons, measured independently by a thermoluminescence technique, is orders of magnitude too small to be responsible for the amount of charge transferred. This result reveals that trapped electrons are not responsible for same-material tribocharging of dielectric particles. Second, same-material tribocharging in grains can result in important long-range electrostatic interactions. However, how these electrostatic interactions contribute to particle clustering remains elusive, primarily due to the lack of direct, detailed observations. Using a high-speed camera that falls with a stream charged grains, we observe for the first time how charged grains can undergo attractive as well as repulsive Kepler-like orbits. Charged particles can be captured in their mutual electrostatic potential and form clusters via multiple bounces. Dielectric polarization effects are directly observed, which lead to additional attractive forces and stabilize "molecule-like" arrangements of charged particles. Third, we have developed a new method to study the charge transfer of microscopic particles based on acoustic levitation techniques. This method allows us to narrow the complex problem of many-particle charging down to precise charge measurements of a single sub-millimeter particle colliding with a target plate. By simply attaching nonpolar groups onto glass surfaces, we show that the contact charging of a particle is highly dependent on

  5. Transferability of polarizable models for ion-water electrostatic interaction

    International Nuclear Information System (INIS)

    Masia, Marco

    2009-01-01

    Studies of ion-water systems at condensed phase and at interfaces have pointed out that molecular and ionic polarization plays an important role for many phenomena ranging from hydrogen bond dynamics to water interfaces' structure. Classical and ab initio Molecular Dynamics simulations reveal that induced dipole moments at interfaces (e.g. air-water and water-protein) are usually high, hinting that polarizable models to be implemented in classical force fields should be very accurate in reproducing the electrostatic properties of the system. In this paper the electrostatic properties of three classical polarizable models for ion-water interaction are compared with ab initio results both at gas and condensed phase. For Li + - water and Cl - -water dimers the reproducibility of total dipole moments obtained with high level quantum chemical calculations is studied; for the same ions in liquid water, Car-Parrinello Molecular Dynamics simulations are used to compute the time evolution of ionic and molecular dipole moments, which are compared with the classical models. The PD2-H2O model developed by the author and coworkers [Masia et al. J. Chem. Phys. 2004, 121, 7362] together with the gaussian intermolecular damping for ion-water interaction [Masia et al. J. Chem. Phys. 2005, 123, 164505] showed to be the fittest in reproducing the ab initio results from gas to condensed phase, allowing for force field transferability.

  6. Food waste management using an electrostatic separator with corona discharge

    Science.gov (United States)

    Lai, Koonchun; Lim, Sooking; Teh, Pehchiong

    2015-05-01

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm.

  7. Food waste management using an electrostatic separator with corona discharge

    International Nuclear Information System (INIS)

    Lai, Koonchun; Teh, Pehchiong; Lim, Sooking

    2015-01-01

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm

  8. Inhibition and promotion of trace pollutant adsorption within electrostatic precipitators.

    Science.gov (United States)

    Clack, Herek L

    2017-08-01

    Among the technologies available for reducing mercury emissions from coal-fired electric utilities is the injection of a powdered sorbent, often some form of activated carbon, into the flue gas upstream of the particulate control device, most commonly an electrostatic precipitator (ESP). Detailed measurements of mercury removal within ESPs are lacking due to the hazardous environment they pose, increasing the importance of analysis and numerical simulation in understanding the mechanisms involved. Our previous analyses revealed that mercury adsorption by particles suspended in the gas and mercury adsorption by particles collected on internal ESP surfaces are not additive removal mechanisms but rather are competitive. The present study expands on this counterintuitive finding. Presented are results from numerical simulations reflecting the complete range of possible mass transfer boundary conditions representing mercury adsorption by the accumulated dust cake covering internal ESP collection electrodes. Using the two mercury removal mechanisms operating concurrently and interdependently always underperforms the sum of the two mechanisms' individual contributions. The dual use of electrostatic precipitators (ESPs) for particulate removal and adsorption of trace gaseous pollutants such as mercury is increasing as mercury regulations become more widespread. Under such circumstances, mercury adsorption by particles suspended in the gas and mercury adsorption by particles collected on internal ESP surfaces are competitive. Together, the two mercury removal mechanisms always underperform the sum of their two independent contributions. These findings can inform strategies sought by electric utilities for reducing the usage costs of mercury sorbents.

  9. Electrostatic Switching in Vertically Oriented Nanotubes for Nonvolatile Memory Applications

    Science.gov (United States)

    Kaul, Anupama B.; Khan, Paul; Jennings, Andrew T.; Greer, Julia R.; Megerian, Krikor G.; Allmen, Paul von

    2009-01-01

    We have demonstrated electrostatic switching in vertically oriented nanotubes or nanofibers, where a nanoprobe was used as the actuating electrode inside an SEM. When the nanoprobe was manipulated to be in close proximity to a single tube, switching voltages between 10 V - 40 V were observed, depending on the geometrical parameters. The turn-on transitions appeared to be much sharper than the turn-off transitions which were limited by the tube-to-probe contact resistances. In many cases, stiction forces at these dimensions were dominant, since the tube appeared stuck to the probe even after the voltage returned to 0 V, suggesting that such structures are promising for nonvolatile memory applications. The stiction effects, to some extent, can be adjusted by engineering the switch geometry appropriately. Nanoscale mechanical measurements were also conducted on the tubes using a custom-built anoindentor inside an SEM, from which preliminary material parameters, such as the elastic modulus, were extracted. The mechanical measurements also revealed that the tubes appear to be well adhered to the substrate. The material parameters gathered from the mechanical measurements were then used in developing an electrostatic model of the switch using a commercially available finite-element simulator. The calculated pull-in voltages appeared to be in agreement to the experimentally obtained switching voltages to first order.

  10. Food waste management using an electrostatic separator with corona discharge

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Koonchun; Teh, Pehchiong [Faculty of Engineering and Green Technology, Universiti Tunku Abdul Rahman (Malaysia); Lim, Sooking [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman (Malaysia)

    2015-05-15

    In Malaysia, municipal solid waste contains a high portion of organic matters, typically contributed by food waste. It is estimated that about 45% of the municipal waste are food waste, followed by the non-food waste such as plastics, metals, glass and others. Food waste, while being properly sorted and contamination free from non-food waste, can be reused (e.g. fertiliser) instead of being landfilled. Therefore, recycling of food waste is crucial not only from the view point of waste management, but also with respect to the reduction of resource losses and greenhouse gases emission. A new waste separation process involved food particles, non-food particles and electrostatic discharge was investigated in this study. The empirical results reveal that the corona electrostatic separation is an environmental-friendly way in recovering foods from municipal waste. The efficiency of the separator, under same operating conditions, varies with the particle size of the food and non-food particles. The highest efficiency of 82% is recorded for the particle sizes between 1.5 and 3.0 mm.

  11. Electrostatic control of phospholipid polymorphism.

    Science.gov (United States)

    Tarahovsky, Y S; Arsenault, A L; MacDonald, R C; McIntosh, T J; Epand, R M

    2000-12-01

    A regular progression of polymorphic phase behavior was observed for mixtures of the anionic phospholipid, cardiolipin, and the cationic phospholipid derivative, 1, 2-dioleoyl-sn-glycero-3-ethylphosphocholine. As revealed by freeze-fracture electron microscopy and small-angle x-ray diffraction, whereas the two lipids separately assume only lamellar phases, their mixtures exhibit a symmetrical (depending on charge ratio and not polarity) sequence of nonlamellar phases. The inverted hexagonal phase, H(II,) formed from equimolar mixtures of the two lipids, i.e., at net charge neutrality (charge ratio (CR((+/-))) = 1:1). When one type of lipid was in significant excess (CR((+/-)) = 2:1 or CR((+/-)) = 1:2), a bicontinuous cubic structure was observed. These cubic phases were very similar to those sometimes present in cellular organelles that contain cardiolipin. Increasing the excess of cationic or anionic charge to CR((+/-)) = 4:1 or CR((+/-)) = 1:4 led to the appearance of membrane bilayers with numerous interlamellar contacts, i.e., sponge structures. It is evident that interactions between cationic and anionic moieties can influence the packing of polar heads and hence control polymorphic phase transitions. The facile isothermal, polymorphic interconversion of these lipids may have important biological and technical implications.

  12. PREFACE: 13th International Conference on Electrostatics

    Science.gov (United States)

    Taylor, D. Martin

    2011-06-01

    Electrostatics 2011 was held in the city of Bangor which is located in North West Wales in an area of outstanding natural beauty close to the Snowdonia mountain range and bordering the Irish Sea. The history of the area goes back into the mists of times, but a continuous technological thread can be traced from the stone- and bronze-age craftsmen, who inhabited the area several thousand years ago, via the civil engineering and fortifications of the Romans and Edward I of England, through Marconi's long-wave trans-Atlantic transmitter near Caernarfon to the conference host. The School of Electronic Engineering at Bangor University has contributed much to the discipline of Electrostatics not only in teaching and research but also in supporting industry. It was a great pleasure for me, therefore, to have the pleasure of welcoming the world's experts in Electrostatics to Bangor in April 2011. In my preface to the Proceedings of Electrostatics 1999, I reported that almost 90 papers were presented. Interestingly, a similar number were presented in 2011 testifying to the importance and endurance of the subject. The all-embracing nature of electrostatics is captured in the pictorial depiction used for the conference logo: a hand-held plasma ball with its close link to gaseous discharges and the superimposed Antarctic aurora highlighting the featured conference themes of atmospheric, planetary and environmental electrostatics. Leading these themes were three invited contributions, the first by Giles Harrison who delivered the Bill Bright Memorial Lecture 'Fair weather atmospheric electricity', Carlos Calle on 'The electrostatic environments of Mars and the Moon' and Istvan Berta on 'Lightning protection - challenges, solutions and questionable steps in the 21st century'. Leading other key sessions were invited papers by Atsushi Ohsawa on 'Statistical analysis of fires and explosions attributed to static electricity over the last 50 years in Japanese industry' and Antonio

  13. Diagnostic Efficiency of MR Imaging of the Knee. Relationship to time Interval between MR and Arthroscopy; Eficacia diagnostica de la RM de rodilla. Relacion con el intervalo de tiempo entre la RM y la artroscopia

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, M. C.; Recondo, J. A.; Aperribay, M.; Gervas, C.; Fernandez, E.; Alustiza, J. M.

    2003-07-01

    To evaluate the efficiency of magnetic resonance (MR) in the diagnosis of knee lesions and how the results are influenced by the time interval between MR and arthroscopy. 248 knees studied by MR were retrospectively analyzed, as well as those which also underwent arthroscopy. Arthroscopy was considered to be the gold standard, MR diagnostic capacity was evaluated for both meniscal and cruciate ligament lesions. Sensitivity, specificity and Kappa index were calculated for the set of all knees included in the study (248), for those in which the time between MR and arthroscopy was less than or equal to three months (134) and for those in which the time between both procedures was less than or equal to one month. Sensitivity, specificity and Kappa index of the MR had global values of 96.5%, 70% and 71%, respectively. When the interval between MR and arthroscopy was less than or equal to three months, sensitivity, specificity and Kappa index were 95.5%, 75% and 72%, respectively. When it was less than or equal to one month, sensitivity was 100%, specificity was 87.5% and Kappa index was 91%. MR is an excellent tool for the diagnosis of knee lesions. Higher MR values of sensitivity, specificity and Kappa index are obtained when the time interval between both procedures is kept to a minimum. (Author) 11 refs.

  14. SIMION, Electrostatic Lens Analysis and Design

    International Nuclear Information System (INIS)

    Dahl, David A.

    2001-01-01

    1 - Description of program or function: SIMION is an electrostatic lens analysis and design program. In SIMION an electrostatic lens is defined as a two-dimensional electrostatic potential array containing both electrode and non-electrode points. The potential array is refined using over-relaxation methods allowing voltage contours and ion trajectories to be computed and plotted. Planar and cylindrical symmetry assumptions allow the two-dimensional fields to support three-dimensional ion trajectory calculations. In addition, the user has the option of writing simple programs which can among other actions control field scale factors, dynamically adjust electrodes, and define explicit three-dimensional field functions (e.g. a quadrupole) used in lieu of array fields in specified portions of the potential array. Magnetic fields can be specified for computing ion trajectories in many electrostatic and magnetic field environments. An interactive graphics interface that uses a high resolution color display and mouse allows the user to view electrodes, trajectories, and contours on the screen prior to plotting, and a memory zoom feature permits expansion of selected areas in the current view. The mouse can be operated to edit the potential array, initialize voltage gradients, or resize the potential array. 2 - Method of solution: SIMION is designed to model the electrostatic fields and forces created by a collection of shaped electrodes given certain symmetry assumptions. The electrostatic fields are modeled as boundary value problem solutions of a Laplace elliptical partial differential equation. A finite difference technique called dynamically self-adjusting over-relaxation is applied to the two-dimensional potential array of points representing electrode and non-electrode regions to obtain a best estimate of the voltages for those points within the array that depict non-electrode regions. A standard fourth-order Runge-Kutta method is used for numerical integration of

  15. Yukawa multipole electrostatics and nontrivial coupling between electrostatic and dispersion interactions in electrolytes

    International Nuclear Information System (INIS)

    Kjellander, Roland; Ramirez, Rosa

    2008-01-01

    An exact treatment of screened electrostatics in electrolyte solutions is presented. In electrolytes the anisotropy of the exponentially decaying electrostatic potential from a molecule extends to the far field region. The full directional dependence of the electrostatic potential from a charged or uncharged molecule remains in the longest range tail (i.e. from all multipole moments). In particular, the range of the potential from an ion and that from an electroneutral polar particle is generally exactly the same. This is in contrast to the case in vacuum or pure polar liquids, where the potential from a single charge is longer ranged than that from a dipole, which is, itself, longer ranged than the one from a quadrupole etc. The orientational dependence of the exponentially screened electrostatic interaction between two molecules in electrolytes is therefore rather complex even at long distances. These facts are formalized in Yukawa multipole expansions of the electrostatic potential and the pair interaction free energy based on the Yukawa function family exp(-κr)/r m , where r is the distance, κ is a decay parameter and m is a positive integer. The expansion is formally exact for electrolytes with molecular solvent and in the primitive model, provided the non-Coulombic interactions between the particles are sufficiently short ranged. The results can also be applied in the Poisson-Boltzmann approximation. Differences and similarities to the ordinary multipole expansion of electrostatics are pointed out. On the other hand, when the non-Coulombic interactions between the constituent particles of the electrolyte solution contain a dispersion 1/r 6 potential, the electrostatic potential from a molecule decays like a power law for long distances rather than as a Yukawa function. This is due to nontrivial coupling between the electrostatic and dispersion interactions. There remains an exponentially decaying component in the electrostatic potential, but it becomes

  16. Research on electrostatic electrification during jet kerosene spraying

    International Nuclear Information System (INIS)

    Liu, Quanzhen; Li, Yipeng; Zhang, Wentian; Sun, Keping

    2013-01-01

    Multiple electrostatic electrifications during aircraft fuelling process may cause a fire disaster or explosion, so study on the protection measure for electrostatic electrification is very important for the security of aircraft fuelling. This paper investigated the electrostatic voltage and charge of the fuel nozzle and metal parts during the fuel spraying by self-designed jet kerosene spraying electrostatic electrification test system. The experimental results indicate that the voltage on the fuel nozzle and metal parts is very dangerous for electrostatic safety if they are not reliably grounded.

  17. Application of electrostatic prevention technology on polyethylene silos

    International Nuclear Information System (INIS)

    Gong, Hong; Liu, Quanzhen; Tan, Fenggui; Zhang, Yunpeng

    2013-01-01

    The main reasons of static electric explosion accidents in polyolefin plant silos were analyzed in this paper, and the study finds that the reasons include control failure of flammable gas content in the feed, high electrification caused by the wind supply, and frequent electrostatic discharge in silos. The electrostatic-reducing technologies of polyolefin powder were introduced, and its application performance in polyolefin plant silos was also clarified. In addition, the methods including FDCS and DGES for evaluation of electrostatic explosion in polyolefin plant silo were proposed. In the end, the risk of electrostatic explosion in PE plant blended silo was evaluated before and after application of electrostatic reducing technology.

  18. Proton emission with a screened electrostatic barrier

    Energy Technology Data Exchange (ETDEWEB)

    Budaca, R. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania); Academy of Romanian Scientists, Bucharest (Romania); Budaca, A.I. [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest-Magurele (Romania)

    2017-08-15

    Half-lives of proton emission for Z ≥ 51 nuclei are calculated within a simple analytical model based on the WKB approximation for the barrier penetration probability which includes the centrifugal and overlapping effects besides the electrostatic repulsion. The model has a single free parameter associated to a Hulthen potential which emulates a Coulomb electrostatic interaction only at short distance. The agreement with experimental data is very good for most of the considered nuclei. Theoretical predictions are made for few cases with uncertain emitting state configuration or incomplete decay information. The model's assignment of the proton orbital momentum is in agreement with the differentiation of the experimental data by orbital momentum values realized with a newly introduced correlation formula. (orig.)

  19. Electrostatically telescoping nanotube nonvolatile memory device

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Jiang Qing

    2007-01-01

    We propose a nonvolatile memory based on carbon nanotubes (CNTs) serving as the key building blocks for molecular-scale computers and investigate the dynamic operations of a double-walled CNT memory element by classical molecular dynamics simulations. The localized potential energy wells achieved from both the interwall van der Waals energy and CNT-metal binding energy make the bistability of the CNT positions and the electrostatic attractive forces induced by the voltage differences lead to the reversibility of this CNT memory. The material for the electrodes should be carefully chosen to achieve the nonvolatility of this memory. The kinetic energy of the CNT shuttle experiences several rebounds induced by the collisions of the CNT onto the metal electrodes, and this is critically important to the performance of such an electrostatically telescoping CNT memory because the collision time is sufficiently long to cause a delay of the state transition

  20. Interaction dynamics of electrostatic solitary waves

    Directory of Open Access Journals (Sweden)

    V. L. Krasovsky

    1999-01-01

    Full Text Available Interaction of nonlinear electrostatic pulses associated with electron phase density holes moving in a collisionless plasma is studied. An elementary event of the interaction is analyzed on the basis of the energy balance in the system consisting of two electrostatic solitary waves. It is established that an intrinsic property of the system is a specific irreversibility caused by a nonadiabatic modification of the internal structure of the holes and their effective heating in the process of the interaction. This dynamical irreversibility is closely connected with phase mixing of the trapped electrons comprising the holes and oscillating in the varying self-consistent potential wells. As a consequence of the irreversibility, the "collisions" of the solitary waves should be treated as "inelastic" ones. This explains the general tendency to the merging of the phase density holes frequently observed in numerical simulation and to corresponding coupling of the solitary waves.

  1. Theory and uses of electrostatic precipitators

    Energy Technology Data Exchange (ETDEWEB)

    Descolas, M

    1974-01-01

    Factors influencing the efficiency of electrostatic precipitators, and the principal uses of this type of dust separator are reviewed. The counter-ionization caused by very high resistivity of the dust can be avoided theoretically by increasing the temperature. The resistance of the settled dust layer is determined not only by the inherent resistivity of the dust but also that of impurities adsorbed by the dust particles, such as water vapor and sulfur dioxide, which tend to decrease the resistance. The maximum possible current intensity decreases with increasing temperature. The current intensity decreases with increasing dust concentration in the waste gas. Electrostatic dust precipitators are successfully used in thermal power plants, waste incinerators, open-hearth furnaces, and oxygen converters. In the pulp industry, they are used to recover sodium sulfate and carbonate between the soda lye boiler and the economizer.

  2. Electrostatic Dust Detector with Improved Sensitivity

    International Nuclear Information System (INIS)

    Boyle, D.P.; Skinner, C.H.; Roquemore, A.L.

    2008-01-01

    Methods to measure the inventory of dust particles and to remove dust if it approaches safety limits will be required in next-step tokamaks such as ITER. An electrostatic dust detector, based on a fine grid of interlocking circuit traces, biased to 30 or 50 V, has been developed for the detection of dust on remote surfaces in air and vacuum environments. Gaining operational experience of dust detection on surfaces in tokamaks is important, however the level of dust generated in contemporary short-pulse tokamaks is comparatively low and high sensitivity is necessary to measure dust on a shot-by-shot basis. We report on modifications in the detection electronics that have increased the sensitivity of the electrostatic dust detector by a factor of up to 120, - a level suitable for measurements on contemporary tokamaks.

  3. 2D Electrostatic Actuation of Microshutter Arrays

    Science.gov (United States)

    Burns, Devin E.; Oh, Lance H.; Li, Mary J.; Jones, Justin S.; Kelly, Daniel P.; Zheng, Yun; Kutyrev, Alexander S.; Moseley, Samuel H.

    2015-01-01

    An electrostatically actuated microshutter array consisting of rotational microshutters (shutters that rotate about a torsion bar) were designed and fabricated through the use of models and experiments. Design iterations focused on minimizing the torsional stiffness of the microshutters, while maintaining their structural integrity. Mechanical and electromechanical test systems were constructed to measure the static and dynamic behavior of the microshutters. The torsional stiffness was reduced by a factor of four over initial designs without sacrificing durability. Analysis of the resonant behavior of the microshutter arrays demonstrates that the first resonant mode is a torsional mode occurring around 3000 Hz. At low vacuum pressures, this resonant mode can be used to significantly reduce the drive voltage necessary for actuation requiring as little as 25V. 2D electrostatic latching and addressing was demonstrated using both a resonant and pulsed addressing scheme.

  4. Contemporary NMR Studies of Protein Electrostatics.

    Science.gov (United States)

    Hass, Mathias A S; Mulder, Frans A A

    2015-01-01

    Electrostatics play an important role in many aspects of protein chemistry. However, the accurate determination of side chain proton affinity in proteins by experiment and theory remains challenging. In recent years the field of nuclear magnetic resonance spectroscopy has advanced the way that protonation states are measured, allowing researchers to examine electrostatic interactions at an unprecedented level of detail and accuracy. Experiments are now in place that follow pH-dependent (13)C and (15)N chemical shifts as spatially close as possible to the sites of protonation, allowing all titratable amino acid side chains to be probed sequence specifically. The strong and telling response of carefully selected reporter nuclei allows individual titration events to be monitored. At the same time, improved frameworks allow researchers to model multiple coupled protonation equilibria and to identify the underlying pH-dependent contributions to the chemical shifts.

  5. Teaching Electrostatics and Entropy in Introductory Physics

    Science.gov (United States)

    Reeves, Mark

    Entropy changes underlie the physics that dominates biological interactions. Indeed, introductory biology courses often begin with an exploration of the qualities of water that are important to living systems. However, one idea that is not explicitly addressed in most introductory physics or biology courses is important contribution of the entropy in driving fundamental biological processes towards equilibrium. I will present material developed to teach electrostatic screening in solutions and the function of nerve cells where entropic effects act to counterbalance electrostatic attraction. These ideas are taught in an introductory, calculus-based physics course to biomedical engineers using SCALEUP pedagogy. Results of student mastering of complex problems that cross disciplinary boundaries between biology and physics, as well as the challenges that they face in learning this material will be presented.

  6. Controlling Charged Particles with Inhomogeneous Electrostatic Fields

    Science.gov (United States)

    Herrero, Federico A. (Inventor)

    2016-01-01

    An energy analyzer for a charged-particle spectrometer may include a top deflection plate and a bottom deflection plate. The top and bottom deflection plates may be non-symmetric and configured to generate an inhomogeneous electrostatic field when a voltage is applied to one of the top or bottom deflection plates. In some instances, the top and bottom deflection plates may be L-shaped deflection plates.

  7. Numerical simulation of electrostatic waves in plasmas

    International Nuclear Information System (INIS)

    Erz, U.

    1981-08-01

    In this paper the propagation of electrostatic waves in plasmas and the non-linear interactions, which occur in the case of large wave amplitudes, are studied using a new numerical method for plasma simulation. This mathematical description is based on the Vlasov-model. Changes in the distribution-function are taken into account and thus plasma kinetic effects can be treated. (orig./HT) [de

  8. SUBMICRON PARTICLES EMISSION CONTROL BY ELECTROSTATIC AGGLOMERATION

    Directory of Open Access Journals (Sweden)

    Andrzej Krupa

    2017-04-01

    Full Text Available The aim of the study was to develop a device for more effective treatment of flue gases from submicron particles emitted by power plants burning bituminous coal and by this way the reduction of environment pollution. Electrostatic processes were employed to this goal, as the most effective solution. The solutions hitherto applied in electrostatic precipitation techniques were designed for large particles, typically with sizes> 5 µm, which are easily removed by the action of electrostatic force on the electrically charged particles. In submicron size range (0.1-1 µm the collection efficiency of an ESP is minimal, because of the low value of electric charge on such particles. In order to avoid problems with the removal of submicron particles of fly ash from the flue gases electrostatic agglomeration has been used. In this process, by applying an alternating electric field, larger charged particles (> 1 µm oscillate, and the particles "collect" smaller uncharged particles. In the developed agglomerator with alternating electric field, the charging of particles and the coagulation takes place in one stage that greatly simplified the construction of the device, compared to other solutions. The scope of this study included measurements of fractional collection efficiency of particles in the system comprising of agglomerator and ESP for PM1 and PM2.5 ranges, in device made in pilot scale. The collection efficiency for PM2.5 was greater than 90% and PM1 slightly dropped below 90%. The mass collection efficiency for PM2.5 was greater than 95%. The agglomerator stage increases the collection efficiency for PM1 at a level of 5-10%.

  9. Cost estimate for electrostatically plugged cusp reactor

    International Nuclear Information System (INIS)

    Dolan, T.J.

    1977-01-01

    A preliminary design of an electrostatically plugged cusp reactor was presented in (UCRL-52142(1976)). The capital costs of the various components of this reactor are estimated and totaled for two different blanket configurations: one having an energy multiplication factor M = 1.2, and the other having M = 1.68. The unoptimized direct capital costs for these cases are found to be about 1400 and 950 $/kWe, respectively

  10. Electrostatic Properties of Particles for Inhalation

    OpenAIRE

    Rowland, Martin

    2015-01-01

    Dry powder inhalers (DPIs) and pressurised metered dose inhalers (pMDIs) aredevices used to deliver therapeutic agents to the lungs. Typically, inhaled activepharmaceutical ingredients (APIs) are electrically resistive materials and are prone toaccumulating electrostatic charge. The build-up of charge on inhaled therapeutics hastraditionally been viewed as a nuisance as it may result in problems such as weighingerrors, agglomeration, adhesion to surfaces and poor flow. Energetic processing st...

  11. 4kV Electrostatic Accelerator Construction

    International Nuclear Information System (INIS)

    Fontaine, M.; Montanno, Luis M.

    2013-01-01

    We design and construct a small one meter linear electron accelerator. It can reach energy up to 4KeV. As a first step we put it in work via electrostatic voltage difference and verifying the acceleration of the electrons with an electrometer. Our plans in the future refer to construct another accelerator of bigger energy and type, for instance, a linear one with resounding cavities. (Author)

  12. Electrostatically actuated torsional resonant sensors and switches

    KAUST Repository

    Younis, Mohammad I.

    2016-12-29

    Embodiments in accordance of a torsional resonant sensor disclosure is configured to actuate a beam structure using electrostatic actuation with an AC harmonic load (e.g., AC and DC voltage sources) that is activated upon detecting a particular agent having a mass above a predefined level. In various embodiments, the beam structure may be different types of resonant structures that is at least partially coated or layered with a selective material.

  13. Low-Shear Microencapsulation and Electrostatic Coating

    Science.gov (United States)

    Morrison, Dennis R.; Mosier, Benjamin

    2005-01-01

    A report presents additional information on the topic of a microencapsulation electrostatic processing system. Information in the report includes micrographs of some microcapsules, a set of diagrams that schematically depict the steps of an encapsulation process, and brief descriptions of (1) alternative versions of the present encapsulation processes, (2) advantages of the present microencapsulation processes over prior microencapsulation processes, and (3) unique and advantageous features of microcapsules produced by the present processes.

  14. Fabrication of a New Electrostatic Linear Actuator

    Science.gov (United States)

    Matsunaga, Takashi; Kondoh, Kazuya; Kumagae, Michihiro; Kawata, Hiroaki; Yasuda, Masaaki; Murata, Kenji; Yoshitake, Masaaki

    2000-12-01

    We propose a new electrostatic linear actuator with a large stroke and a new process for fabricating the actuator. A moving slider with many teeth on both sides is suspended above lower electrodes on a substrate by two bearings. A photoresist is used as a sacrificial layer. Both the slider and the bearings are fabricated by Ni electroplating. The bearings are fabricated by the self-alignment technique. Bearings with 0.6 μm clearance can be easily fabricated. All processes are performed at low temperatures up to 110°C. It is confirmed that the slider can be moved mechanically, and also can be moved by about 10 μm when a voltage pulse of 50 V is applied between the slider and the lower electrodes when the slider is upside down. However, the slider cannot move continuously because of friction. We also calculate the electrostatic force acting on one slider tooth. The simulation result shows that the reduction of the electrostatic force to the vertical direction is very important for mechanical movement of the actuator.

  15. Nonlinear Dynamics of Electrostatically Actuated MEMS Arches

    KAUST Repository

    Al Hennawi, Qais M.

    2015-05-01

    In this thesis, we present theoretical and experimental investigation into the nonlinear statics and dynamics of clamped-clamped in-plane MEMS arches when excited by an electrostatic force. Theoretically, we first solve the equation of motion using a multi- mode Galarkin Reduced Order Model (ROM). We investigate the static response of the arch experimentally where we show several jumps due to the snap-through instability. Experimentally, a case study of in-plane silicon micromachined arch is studied and its mechanical behavior is measured using optical techniques. We develop an algorithm to extract various parameters that are needed to model the arch, such as the induced axial force, the modulus of elasticity, and the initially induced initial rise. After that, we excite the arch by a DC electrostatic force superimposed to an AC harmonic load. A softening spring behavior is observed when the excitation is close to the first resonance frequency due to the quadratic nonlinearity coming from the arch geometry and the electrostatic force. Also, a hardening spring behavior is observed when the excitation is close to the third (second symmetric) resonance frequency due to the cubic nonlinearity coming from mid-plane stretching. Then, we excite the arch by an electric load of two AC frequency components, where we report a combination resonance of the summed type. Agreement is reported among the theoretical and experimental work.

  16. Biomolecular electrostatics and solvation: a computational perspective.

    Science.gov (United States)

    Ren, Pengyu; Chun, Jaehun; Thomas, Dennis G; Schnieders, Michael J; Marucho, Marcelo; Zhang, Jiajing; Baker, Nathan A

    2012-11-01

    An understanding of molecular interactions is essential for insight into biological systems at the molecular scale. Among the various components of molecular interactions, electrostatics are of special importance because of their long-range nature and their influence on polar or charged molecules, including water, aqueous ions, proteins, nucleic acids, carbohydrates, and membrane lipids. In particular, robust models of electrostatic interactions are essential for understanding the solvation properties of biomolecules and the effects of solvation upon biomolecular folding, binding, enzyme catalysis, and dynamics. Electrostatics, therefore, are of central importance to understanding biomolecular structure and modeling interactions within and among biological molecules. This review discusses the solvation of biomolecules with a computational biophysics view toward describing the phenomenon. While our main focus lies on the computational aspect of the models, we provide an overview of the basic elements of biomolecular solvation (e.g. solvent structure, polarization, ion binding, and non-polar behavior) in order to provide a background to understand the different types of solvation models.

  17. Electrostatic purification of uranium mine stope atmospheres

    International Nuclear Information System (INIS)

    Case, G.; Phyper, J.D.; Lowe, L.M.; Chambers, D.B.

    1986-01-01

    Electrostatic precipitators have been and are currently being used to reduce levels of radioactive aerosols in uranium mine stope atmospheres. Historically, while the electrostatic precipitators have been reported to be successful in reducing levels of radioactive aerosols many practical problems have been encountered with their use in the underground mine environment. Electrical short circuiting appears to have been the major problem with the use of precipitators in humid underground environments. On the basis of literature reviewed for this study it seems that the problems encountered in the past can be overcome. The most likely use of a precipitator in an underground uranium mine is to treat some or all of the air immediately upstream of a work station. The possible locations and uses of a precipitator would vary from work station to work station and from mine to mine. The desirability and cost of using elctrostatic precipitators to purify the air entering a work station are application specific. SENES Consultants therefore is not recommending for or against the use of electrostatic precipitators in underground uranium mines. The information provided in this report can be used however to assist in such determinations. 72 refs

  18. Development of coaxial speaker-like non-contact electrostatic sensor for aviation engine exhaust electrostatic character research

    Directory of Open Access Journals (Sweden)

    Du Zhaoheng

    2015-01-01

    Full Text Available Electrostatic sensor is the most important equipment in aero-engine exhaust electrostatic character research. By comparing a variety of sensor test programs, the coaxial speaker-like noncontact electrostatic sensor program is proposed. Numerical simulation analysis indicates the electric field distribution of electrostatic sensor, the influence principle of gap width, outer diameter, center diameter, angle and other factors on the sensor capacitance values which identify the key indicators of electrostatic sensor. The experiment test shows that the simulation analysis is in good agreement with the experimental results.

  19. Dynamic simulations of many-body electrostatic self-assembly

    Science.gov (United States)

    Lindgren, Eric B.; Stamm, Benjamin; Maday, Yvon; Besley, Elena; Stace, A. J.

    2018-03-01

    Two experimental studies relating to electrostatic self-assembly have been the subject of dynamic computer simulations, where the consequences of changing the charge and the dielectric constant of the materials concerned have been explored. One series of calculations relates to experiments on the assembly of polymer particles that have been subjected to tribocharging and the simulations successfully reproduce many of the observed patterns of behaviour. A second study explores events observed following collisions between single particles and small clusters composed of charged particles derived from a metal oxide composite. As before, observations recorded during the course of the experiments are reproduced by the calculations. One study in particular reveals how particle polarizability can influence the assembly process. This article is part of the theme issue `Modern theoretical chemistry'.

  20. RNA folding: structure prediction, folding kinetics and ion electrostatics.

    Science.gov (United States)

    Tan, Zhijie; Zhang, Wenbing; Shi, Yazhou; Wang, Fenghua

    2015-01-01

    Beyond the "traditional" functions such as gene storage, transport and protein synthesis, recent discoveries reveal that RNAs have important "new" biological functions including the RNA silence and gene regulation of riboswitch. Such functions of noncoding RNAs are strongly coupled to the RNA structures and proper structure change, which naturally leads to the RNA folding problem including structure prediction and folding kinetics. Due to the polyanionic nature of RNAs, RNA folding structure, stability and kinetics are strongly coupled to the ion condition of solution. The main focus of this chapter is to review the recent progress in the three major aspects in RNA folding problem: structure prediction, folding kinetics and ion electrostatics. This chapter will introduce both the recent experimental and theoretical progress, while emphasize the theoretical modelling on the three aspects in RNA folding.

  1. Loop Electrostatics Asymmetry Modulates the Preexisting Conformational Equilibrium in Thrombin.

    Science.gov (United States)

    Pozzi, Nicola; Zerbetto, Mirco; Acquasaliente, Laura; Tescari, Simone; Frezzato, Diego; Polimeno, Antonino; Gohara, David W; Di Cera, Enrico; De Filippis, Vincenzo

    2016-07-19

    Thrombin exists as an ensemble of active (E) and inactive (E*) conformations that differ in their accessibility to the active site. Here we show that redistribution of the E*-E equilibrium can be achieved by perturbing the electrostatic properties of the enzyme. Removal of the negative charge of the catalytic Asp102 or Asp189 in the primary specificity site destabilizes the E form and causes a shift in the 215-217 segment that compromises substrate entrance. Solution studies and existing structures of D102N document stabilization of the E* form. A new high-resolution structure of D189A also reveals the mutant in the collapsed E* form. These findings establish a new paradigm for the control of the E*-E equilibrium in the trypsin fold.

  2. 基于不确定时间区间TBN的洪水漫坝风险分析%Risk Analysis of Flood Overtopping Based on Uncertain Time Interval TBN

    Institute of Scientific and Technical Information of China (English)

    涂传飞; 王剑; 王红卫

    2013-01-01

    In the process of flood overtopping,the uncertainty of events' duration time caused by state uncertainty of natural conditions,dam and emergency measures,and the effect of emergency measures are both key factors that affect the flood overtopping risk.The traditional time interval was transformed into an uncertain time interval and an uncertain time interval Temporal Bayesian Network (TBN) was proposed.After that,a new inferring algorithm of the TBN was discussed.On the basis,flood overtopping risk analysis model,in which emergency measures were considered,was established.Finally,the simulation result shows that the model can accumulate information,judge the importance of each emergency measure,express the state uncertainty and time uncertainty which both exist in the process of flood overtopping and accordingly increase the accuracy of flood overtopping risk analysis.%洪水漫坝过程中,自然条件、坝体及应急处置等状态的不确定性所导致的事件持续时间的不确定性,以及应急处置措施的效果是影响漫坝风险的关键因素.首先将传统时间区间改造为不确定时间区间,提出了一种不确定时间区间时间贝叶斯网络(TBN),并推导了该TBN的推理算法.在此基础上构建了考虑应急处置措施的洪水漫坝风险分析模型.仿真结果表明该模型具有信息时间累积能力,能判断各应急处置措施的重要程度,表达了洪水漫坝过程中同时存在的状态不确定性和时间不确定性,提高了漫坝风险分析的精度.

  3. A 1-h time interval between a meal containing iron and consumption of tea attenuates the inhibitory effects on iron absorption: a controlled trial in a cohort of healthy UK women using a stable iron isotope.

    Science.gov (United States)

    Ahmad Fuzi, Salma F; Koller, Dagmar; Bruggraber, Sylvaine; Pereira, Dora Ia; Dainty, Jack R; Mushtaq, Sohail

    2017-12-01

    Background: Tea has been shown to be a potent inhibitor of nonheme iron absorption, but it remains unclear whether the timing of tea consumption relative to a meal influences iron bioavailability. Objective: The aim of the study was to investigate the effect of a 1-h time interval of tea consumption on nonheme iron absorption in an iron-containing meal in a cohort of iron-replete, nonanemic female subjects with the use of a stable isotope ( 57 Fe). Design: Twelve women (mean ± SD age: 24.8 ± 6.9 y) were administered a standardized porridge meal extrinsically labeled with 4 mg 57 Fe as FeSO 4 on 3 separate occasions, with a 14-d time interval between each test meal (TM). The TM was administered with water (TM-1), with tea administered simultaneously (TM-2), and with tea administered 1 h postmeal (TM-3). Fasted venous blood samples were collected for iron isotopic analysis and measurement of iron status biomarkers. Fractional iron absorption was estimated by the erythrocyte iron incorporation method. Results: Iron absorption was 5.7% ± 8.5% (TM-1), 3.6% ± 4.2% (TM-2), and 5.7% ± 5.4% (TM-3). Mean fractional iron absorption was found to be significantly higher (2.2%) when tea was administered 1 h postmeal (TM-3) than when tea was administered simultaneously with the meal (TM-2) ( P = 0.046). An ∼50% reduction in the inhibitory effect of tea (relative to water) was observed, from 37.2% (TM-2) to 18.1% (TM-3). Conclusions: This study shows that tea consumed simultaneously with an iron-containing porridge meal leads to decreased nonheme iron absorption and that a 1-h time interval between a meal and tea consumption attenuates the inhibitory effect, resulting in increased nonheme iron absorption. These findings are not only important in relation to the management of iron deficiency but should also inform dietary advice, especially that given to those at risk of deficiency. This trial was registered at clinicaltrials.gov as NCT02365103. © 2017 American Society for

  4. Efficiency determination of an electrostatic lunar dust collector by discrete element method

    Science.gov (United States)

    Afshar-Mohajer, Nima; Wu, Chang-Yu; Sorloaica-Hickman, Nicoleta

    2012-07-01

    Lunar grains become charged by the sun's radiation in the tenuous atmosphere of the moon. This leads to lunar dust levitation and particle deposition which often create serious problems in the costly system deployed in lunar exploration. In this study, an electrostatic lunar dust collector (ELDC) is proposed to address the issue and the discrete element method (DEM) is used to investigate the effects of electrical particle-particle interactions, non-uniformity of the electrostatic field, and characteristics of the ELDC. The simulations on 20-μm-sized lunar particles reveal the electrical particle-particle interactions of the dust particles within the ELDC plates require 29% higher electrostatic field strength than that without the interactions for 100% collection efficiency. For the given ELDC geometry, consideration of non-uniformity of the electrostatic field along with electrical interactions between particles on the same ELDC geometry leads to a higher requirement of ˜3.5 kV/m to ensure 100% particle collection. Notably, such an electrostatic field is about 103 times less than required for electrodynamic self-cleaning methods. Finally, it is shown for a "half-size" system that the DEM model predicts greater collection efficiency than the Eulerian-based model at all voltages less than required for 100% efficiency. Halving the ELDC dimensions boosts the particle concentration inside the ELDC, as well as the resulting field strength for a given voltage. Though a lunar photovoltaic system was the subject, the results of this study are useful for evaluation of any system for collecting charged particles in other high vacuum environment using an electrostatic field.

  5. Some theoretical aspects of electrostatic double layers

    International Nuclear Information System (INIS)

    Carlqvist, P.

    1978-11-01

    A review is presented of the main results of the theoretical work on electrostatic double layers. The general properties of double layers are first considered. Then the time-independent double layer is discussed. The discussion deals with the potential drop, the thickness, and some necessary criteria for the existence and stability of the layer. As a complement to the study of the timeindependent double layer a few remarks are also made upon the timedependent double layer. Finally the question of how double layers are formed and maintained is treated. Several possible formation mechanisms are considered. (author)

  6. The electrostatic cylindrical sheath in a plasma

    International Nuclear Information System (INIS)

    Wang Chunhua; Sun Xiaoxia; Bai Dongxue

    2004-01-01

    The electrostatic sheath with a cylindrical geometry in an ion-electron plasma is investigated. Assuming a Boltzmann response to electrons and cold ions with bulk flow, it is shown that the radius of the cylindrical geometry do not affect the sheath potential significantly. The authors also found that the sheath potential profile is steeper in the cylindrical sheath compared to the slab sheath. The distinct feature of the cylindrical sheath is that the ion density distribution is not monotonous. The sheath region can be divided into three regions, two ascendant regions and one descendant region. (author)

  7. Charging device for an electrostatic accelerator

    International Nuclear Information System (INIS)

    Pivovar, L.I.; Khurgin, K.M.

    1983-01-01

    The invention relates to electrostatic accelerators operating in compressed gases and charged by a charge-carrying belt transport device with driving and driven shafts. The aim of the invention is the increase of service life of the device by decreasing deflection of the charge-carrying belt in high-voltage conductor operation at high voltages. Increase of survice life of the device is provided due to the fact that the belt as a whole is more stable and it runs true without slacking shielding rods

  8. Desensitizing nano powders to electrostatic discharge ignition

    International Nuclear Information System (INIS)

    Steelman, Ryan; Daniels, Michael A.

    2015-01-01

    Electrostatic discharge (ESD) is a main cause for ignition in powder media ranging from grain silos to fireworks. Nanoscale particles are orders of magnitude more ESD ignition sensitive than their micron scale counterparts. This study shows that at least 13 vol. % carbon nanotubes (CNT) added to nano-aluminum and nano-copper oxide particles (nAl + CuO) eliminates ESD ignition sensitivity. The CNT act as a conduit for electric energy and directs electric charge through the powder to desensitize the reactive mixture to ignition. For nanoparticles, the required CNT concentration for desensitizing ESD ignition acts as a diluent to quench energy propagation.

  9. Nonadiabatic transitions in electrostatically trapped ammonia molecules

    International Nuclear Information System (INIS)

    Kirste, Moritz; Schnell, Melanie; Meijer, Gerard; Sartakov, Boris G.

    2009-01-01

    Nonadiabatic transitions are known to be major loss channels for atoms in magnetic traps but have thus far not been experimentally reported upon for trapped molecules. We have observed and quantified losses due to nonadiabatic transitions for three isotopologues of ammonia in electrostatic traps by comparing the trapping times in traps with a zero and a nonzero electric field at the center. Nonadiabatic transitions are seen to dominate the overall loss rate even for the present samples that are at relatively high temperatures of 30 mK. It is anticipated that losses due to nonadiabatic transitions in electric fields are omnipresent in ongoing experiments on cold molecules.

  10. Orbital dynamics in a storage ring with electrostatic bending

    International Nuclear Information System (INIS)

    Mane, S.R.

    2008-01-01

    A storage ring where electrostatic fields contribute to the bending and focusing of the orbital motion has some novel features because, unlike a magnetostatic field, an electrostatic field can change the kinetic energy of the particles. I present analytical formulas to calculate the linear focusing gradient, dispersion, momentum compaction and natural chromaticity for a storage ring with a radial electrostatic field. I solve the formulas explicitly for a weak focusing model.

  11. Waferscale Electrostatic Quadrupole Array for Multiple Ion Beam Manipulation

    OpenAIRE

    Vinayakumar, K. B.; Persaud, A.; Seidl, P. A.; Ji, Q.; Waldron, W. L.; Schenkel, T.; Ardanuc, S.; Lal, A.

    2018-01-01

    We report on the first through-wafer silicon-based Electrostatic Quadrupole Array (ESQA) to focus high energy ion beams. This device is a key enabler for a wafer based accelerator architecture that lends itself to orders-of-magnitude reduction in cost, volume and weight of charged particle accelerators. ESQs are a key building block in developing compact Multiple Electrostatic Quadrupole Array Linear Accelerator (MEQALAC) [1]. In a MEQALAC electrostatic forces are used to focus ions, and elec...

  12. Development and Application Prospects of Pneumatic Electrostatic Sprayer in Orchard

    OpenAIRE

    Zhou, Yan; Qi, Li-jun; Jia, Shou-xing; Zheng, Xuan; Meng, Xiang-jin; Tang, Zhi-hui; Shen, Cong-ju

    2012-01-01

    We firstly introduce existing situations of development of electrostatic spraying technology both at home and abroad. On the basis of such problems as serious drift, loss and deterioration of environment during orchard spraying in Xinjiang, we design and develop a new electrostatic sprayer which can effectively reduce the pesticide, improve the adhesion rate of pesticide in the target, and reduce pollution on human body and environment. Using electrostatic induction principle, this electrosta...

  13. Electrostatic chuck consisting of polymeric electrostatic inductive fibers for handling of objects with rough surfaces

    International Nuclear Information System (INIS)

    Dhelika, Radon; Sawai, Kenji; Saito, Shigeki; Takahashi, Kunio; Takarada, Wataru; Kikutani, Takeshi

    2013-01-01

    An electrostatic chuck (ESC) is a type of reversible dry adhesive which clamps objects by means of electrostatic force. Currently an ESC is used only for objects having flat surfaces because the attractive force is reduced for rough surfaces. An ESC that can handle objects with rough surfaces will expand its applications to MEMS (micro electro mechanical system) or optical parts handling. An ESC consisting of compliant electrostatic inductive fibers which conform to the profile of the surface has been proposed for such use. This paper aims at furthering previous research by observing the attractive force/pressure generated, both theoretically and experimentally, through step-by-step fabrication and analysis. Additionally, how the proposed fiber ESC behaves toward rough surfaces is also observed. The attractive force/pressure of the fiber ESC is theoretically investigated using a robust mechano-electrostatic model. Subsequently, a prototype of the fiber ESC consisting of ten fibers arranged at an angle is employed to experimentally observe its attractive force/pressure for objects with rough surfaces. The attractive force of the surface which is modeled as a sinusoidal wave with various amplitudes is observed, through which the feasibility of a fiber ESC is justified. (paper)

  14. Application of Electrostatic Extrusion – Flavour Encapsulation and Controlled Release

    OpenAIRE

    Branko Bugarski; Viktor Nedovic; Bojana Obradovic; Jasna Djonlagic; Nevenka Rajic; Verica Manojlovic

    2008-01-01

    The subject of this study was the development of flavour alginate formulationsaimed for thermally processed foods. Ethyl vanilline was used as the model flavourcompound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline inalginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethylvanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about450 μm. Chemical characterization by H-NMR spectroscopy revealed that the algina...

  15. Interaction and dynamics of ambient water adlayers on graphite probed using AFM voltage nanolithography and electrostatic force microscopy

    International Nuclear Information System (INIS)

    Gowthami, T; Raina, Gargi; Kurra, Narendra

    2014-01-01

    In this work, we report the impact of the interaction and dynamics of increasing ambient water adlayers on etch patterns on a hydrophobic highly oriented pyrolytic graphite (HOPG) surface obtained using atomic force microscopy (AFM) voltage nanolithography in contact mode by applying a positive bias to the sample. The changes in the dimensions of the etch patterns were investigated as a function of the increasing number of water adlayers present on the HOPG, which is varied by changing the time interval since HOPG cleavage. Changes in the width of the etch patterns and the surrounding water droplets were monitored with time, using intermittent-contact-mode AFM. Electrostatic force microscopy (EFM) has been employed to study the charged nature of the etch patterns and the neighboring water film with time. The width of the etch patterns made on freshly cleaved HOPG shows an increase of ∼33% over 48 h, whereas nine-day-old cleaved HOPG shows a 79% increase over the same period. No changes in the dimensions are observed while imaging in a nitrogen atmosphere soon after lithography. In ambient conditions, the EFM phase shift of the patterns shows a large change of ∼84–88% over 30 h. This study demonstrates the effect of the stored electrostatic energy of a polarized ice-like water adlayer, resulting in changes in the dimensions of the etch patterns long after lithography, whereas liquid-like water droplets do not affect the etch patterns. (paper)

  16. Embedding beyond electrostatics-The role of wave function confinement.

    Science.gov (United States)

    Nåbo, Lina J; Olsen, Jógvan Magnus Haugaard; Holmgaard List, Nanna; Solanko, Lukasz M; Wüstner, Daniel; Kongsted, Jacob

    2016-09-14

    We study excited states of cholesterol in solution and show that, in this specific case, solute wave-function confinement is the main effect of the solvent. This is rationalized on the basis of the polarizable density embedding scheme, which in addition to polarizable embedding includes non-electrostatic repulsion that effectively confines the solute wave function to its cavity. We illustrate how the inclusion of non-electrostatic repulsion results in a successful identification of the intense π → π(∗) transition, which was not possible using an embedding method that only includes electrostatics. This underlines the importance of non-electrostatic repulsion in quantum-mechanical embedding-based methods.

  17. Investigating ESD sensitivity in electrostatic SiGe MEMS

    International Nuclear Information System (INIS)

    Sangameswaran, Sandeep; De Coster, Jeroen; Linten, Dimitri; Scholz, Mirko; Thijs, Steven; Groeseneken, Guido; De Wolf, Ingrid

    2010-01-01

    The sensitivity of electrostatically actuated SiGe microelectromechanical systems to electrostatic discharge events has been investigated in this paper. Torsional micromirrors and RF microelectromechanical systems (MEMS) actuators have been used as two case studies to perform this study. On-wafer electrostatic discharge (ESD) measurement methods, such as the human body model (HBM) and machine model (MM), are discussed. The impact of HBM ESD zap tests on the functionality and behavior of MEMS is explained and the ESD failure levels of MEMS have been verified by failure analysis. It is demonstrated that electrostatic MEMS devices have a high sensitivity to ESD and that it is essential to protect them.

  18. Influência do intervalo de tempo entre as sessões de alongamento no ganho de flexibilidade dos isquiotibiais Influence of the time interval between stretching sessions on increased hamstring flexibility

    Directory of Open Access Journals (Sweden)

    Zenewton André da Silva Gama

    2009-04-01

    Full Text Available CONTEXTO: A otimização do treino de flexibilidade está relacionada com o uso de parâmetros adequados de alongamento. Entretanto, o intervalo de tempo adequado entre as sessões de alongamento tem sido pouco investigado. OBJETIVO: Verificar se a variação no intervalo de tempo entre sessões de alongamento influencia no ganho de flexibilidade. MÉTODOS: 28 mulheres, com idade de 22,5 ± 1,8 anos, foram distribuídas aleatoriamente em três grupos. Aplicaram-se 10 sessões de alongamento nos isquiotibiais do membro direito. O grupo 0X (n = 8 foi o controle e não recebeu alongamento. O grupo 3X (n = 10 alongou três vezes por semana (intervalo de 48 horas e o grupo 5X (n = 10, cinco vezes (intervalo de 24 horas. Aplicaram-se 10 sessões de alongamento (sustentar-relaxar nos isquiotibiais direitos. As medidas foram tomadas por análise fotométrica no programa AutoCad® 2000. A análise estatística foi realizada com ANOVA e teste post hoc de Newman-Keuls adotando um p-valor referencial de 0,05. RESULTADOS: Após 10 sessões, identificou-se aumento da flexibilidade nos grupos experimentais, porém sem diferença entre estes. O grupo 3X aumentou significativamente a partir do 10º dia do programa (quinta sessão e o grupo 5X, a partir do terceiro (terceira sessão. CONCLUSÕES: O alongamento aumenta a flexibilidade dos isquiotibiais, independente do tempo entre as sessões (24 ou 48 horas; e a variável tempo não influencia o ganho de flexibilidade total. Porém, com cinco sessões semanais, ganha-se flexibilidade mais rapidamente. Isso sugere que o ganho de flexibilidade é sessão-dependente.CONTEXT: The optimization of flexibility training is related to the use of ideal stretching parameters. However, the time interval between sessions has been little investigated. OBJECTIVE: To verify if the variation in time interval between stretching sessions influences in flexibility gain. METHODOLOGY: Twenty-eight women, average age of 22.5 ± 1

  19. Electrostatic sensor modeling for torque measurements

    Directory of Open Access Journals (Sweden)

    M. Mika

    2017-09-01

    Full Text Available Torque load measurements play an important part in various engineering applications, as for automotive industry, in which the drive torque of a motor has to be determined. A widely used measuring method are strain gauges. A thin flexible foil, which supports a metallic pattern, is glued to the surface of the object the torque is being applied to. In case of a deformation due to the torque load, the change in the electrical resistance is measured. With the combination of constitutive equations the applied torque load is determined by the change of electrical resistance. The creep of the glue and the foil material, together with the temperature and humidity dependence, may become an obstacle for some applications Kapralov and Fesenko(1984. Thus, there have been optical and magnetical, as well as capacitive sensors introduced . This paper discusses the general idea behind an electrostatic capacitive sensor based on a simple draft of an exemplary measurement setup. For better understanding an own electrostatical, geometrical and mechanical model of this setup has been developed.

  20. The morphology of electrostatic tripolar regions

    International Nuclear Information System (INIS)

    Nocera, L.

    2008-01-01

    Electrostatic tripolar regions in plasmas develop a skewness of their own electric potential waveform as a peculiar morphological property, which distinguishes them from symmetric electrostatic solitary waves. Within the collision-less, kinetic treatment developed here, this property holds if the velocity distributions of electrons and ions are singular in value, irrespective of their smoothness at the region's boundary and of the smoothness of the potential waveform and of the electron and ion density distributions. These singularities are integrable, and are of the logarithmic and jump type: the former occur at isolated points in phase space; the latter occur on the left branch of the electron separatrix and on the left branch of the ion sub-separatrix. The distributions are non-negative if, at its local extrema, the potential waveform is skewed to the left, in agreement with observations, and if the skewness is smaller than a given bound: a sufficient condition for such skewness to be small about the minimum of the potential waveform is that a sufficiently fast electron beam exists on the high-potential boundary of the tripolar region. In those special cases in which the particle distributions are continuous in value, the above mentioned singularities affect their space and velocity derivatives. These results could be extracted from very general considerations on the degree of smoothness of the spatial distribution of the electric potential and on the non-negativity of the electron and ion distributions, without the assistance of any specific models

  1. Highly Tunable Electrothermally and Electrostatically Actuated Resonators

    KAUST Repository

    Hajjaj, Amal Z.

    2016-03-30

    This paper demonstrates experimentally, theoretically, and numerically for the first time, a wide-range tunability of an in-plane clamped-clamped microbeam, bridge, and resonator actuated electrothermally and electrostatically. Using both actuation methods, we demonstrate that a single resonator can be operated at a wide range of frequencies. The microbeam is actuated electrothermally by passing a dc current through it, and electrostatically by applying a dc polarization voltage between the microbeam and the stationary electrode. We show that when increasing the electrothermal voltage, the compressive stress inside the microbeam increases, which leads eventually to its buckling. Before buckling, the fundamental frequency decreases until it drops to very low values, almost to zero. After buckling, the fundamental frequency increases, which is shown to be as high as twice the original resonance frequency. Adding a dc bias changes the qualitative nature of the tunability both before and after buckling, which adds another independent way of tuning. This reduces the dip before buckling, and can eliminate it if desired, and further increases the fundamental frequency after buckling. Analytical results based on the Galerkin discretization of the Euler Bernoulli beam theory are generated and compared with the experimental data and simulation results of a multi-physics finite-element model. A good agreement is found among all the results. [2015-0341

  2. Electrostatic sensor modeling for torque measurements

    Science.gov (United States)

    Mika, Michał; Dannert, Mirjam; Mett, Felix; Weber, Harry; Mathis, Wolfgang; Nackenhorst, Udo

    2017-09-01

    Torque load measurements play an important part in various engineering applications, as for automotive industry, in which the drive torque of a motor has to be determined. A widely used measuring method are strain gauges. A thin flexible foil, which supports a metallic pattern, is glued to the surface of the object the torque is being applied to. In case of a deformation due to the torque load, the change in the electrical resistance is measured. With the combination of constitutive equations the applied torque load is determined by the change of electrical resistance. The creep of the glue and the foil material, together with the temperature and humidity dependence, may become an obstacle for some applications Kapralov and Fesenko (1984). Thus, there have been optical and magnetical, as well as capacitive sensors introduced). This paper discusses the general idea behind an electrostatic capacitive sensor based on a simple draft of an exemplary measurement setup. For better understanding an own electrostatical, geometrical and mechanical model of this setup has been developed.

  3. Electrostatic ion thrusters - towards predictive modeling

    Energy Technology Data Exchange (ETDEWEB)

    Kalentev, O.; Matyash, K.; Duras, J.; Lueskow, K.F.; Schneider, R. [Ernst-Moritz-Arndt Universitaet Greifswald, D-17489 (Germany); Koch, N. [Technische Hochschule Nuernberg Georg Simon Ohm, Kesslerplatz 12, D-90489 Nuernberg (Germany); Schirra, M. [Thales Electronic Systems GmbH, Soeflinger Strasse 100, D-89077 Ulm (Germany)

    2014-02-15

    The development of electrostatic ion thrusters so far has mainly been based on empirical and qualitative know-how, and on evolutionary iteration steps. This resulted in considerable effort regarding prototype design, construction and testing and therefore in significant development and qualification costs and high time demands. For future developments it is anticipated to implement simulation tools which allow for quantitative prediction of ion thruster performance, long-term behavior and space craft interaction prior to hardware design and construction. Based on integrated numerical models combining self-consistent kinetic plasma models with plasma-wall interaction modules a new quality in the description of electrostatic thrusters can be reached. These open the perspective for predictive modeling in this field. This paper reviews the application of a set of predictive numerical modeling tools on an ion thruster model of the HEMP-T (High Efficiency Multi-stage Plasma Thruster) type patented by Thales Electron Devices GmbH. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. Development of Electrostatically Clean Solar Array Panels

    Science.gov (United States)

    Stern, Theodore G.

    2000-01-01

    Certain missions require Electrostatically Clean Solar Array (ECSA) panels to establish a favorable environment for the operation of sensitive scientific instruments. The objective of this program was to demonstrate the feasibility of an ECSA panel that minimizes panel surface potential below 100mV in LEO and GEO charged particle environments, prevents exposure of solar cell voltage and panel insulating surfaces to the ambient environment, and provides an equipotential, grounded structure surrounding the entire panel. An ECSA panel design was developed that uses a Front Side Aperture-Shield (FSA) that covers all inter-cell areas with a single graphite composite laminate, composite edge clips for connecting the FSA to the panel substrate, and built-in tabs that interconnect the FSA to conductive coated coverglasses using a conductive adhesive. Analysis indicated the ability of the design to meet the ECSA requirements. Qualification coupons and a 0.5m x 0.5m prototype panel were fabricated and tested for photovoltaic performance and electrical grounding before and after exposure to acoustic and thermal cycling environments. The results show the feasibility of achieving electrostatic cleanliness with a small penalty in mass, photovoltaic performance and cost, with a design is structurally robust and compatible with a wide range of current solar panel technologies.

  5. Variação da evapotranspiração de referência calculada em diferentes intervalos de tempo Variation of the reference evapotranspiration calculated for different times interval

    Directory of Open Access Journals (Sweden)

    Álvaro J. Back

    2007-04-01

    Full Text Available Valores de evapotranspiração de referência foram calculados em intervalos de um, cinco, dez, quinze dias e mensal. Foram utilizados dados meteorológicos da Estação Meteorológica de Urussanga - SC (latitude 28°31'S, longitude 49°19'W referentes ao período de 1981 a 2004. A evapotranspiração de referência foi calculada pelo método de Penman-Monteith com base nas médias das variáveis meteorológicas dos diferentes períodos estudados. Observou-se que não houve diferenças significativas nas médias de evapotranspiração calculadas nos diversos intervalos de tempo. No entanto, houve diferenças significativas na dispersão dos valores em torno da média. Para valores diários, foi obtido coeficiente de variação (C.V. entre 30 e 40%, e para valores mensais, variou entre 6% e 12%. Observou-se, também, que os dados de evapotranspiração se ajustaram à distribuição Beta, e assim foram estimados, para cada mês, os valores de evapotranspiração de referência com probabilidades de 5; 10; 25; 50; 75; 90 e 95%.Reference evapotranspiration values were calculated for time interval of one, five, ten, fifteen days and monthly. Meteorological series data from 1981 to 2004 from Urussanga Weather Station (latitude 28°31'S, longitude 49°19'W were used to calculate reference evapotranspiration with Penman-Monteith method with mean of meteorological variables for every time intervals. No difference was observed in average reference evapotranspiration computed in all time steps. However, some difference in variations of data around the average was observed. For daily value, the variation coefficient varies from 30 to 40% and for monthly values de coefficient variation varied from 6 to 12%. It was observed that the reference evapotranspirations adjusted very well to Beta distribution probability, and the reference evapotranspiration with probability of 5; 10; 25; 50; 75; 90 e 95% was estimated.

  6. Interdomain electron transfer in cellobiose dehydrogenase is governed by surface electrostatics.

    Science.gov (United States)

    Kadek, Alan; Kavan, Daniel; Marcoux, Julien; Stojko, Johann; Felice, Alfons K G; Cianférani, Sarah; Ludwig, Roland; Halada, Petr; Man, Petr

    2017-02-01

    Cellobiose dehydrogenase (CDH) is a fungal extracellular oxidoreductase which fuels lytic polysaccharide monooxygenase with electrons during cellulose degradation. Interdomain electron transfer between the flavin and cytochrome domain in CDH, preceding the electron flow to lytic polysaccharide monooxygenase, is known to be pH dependent, but the exact mechanism of this regulation has not been experimentally proven so far. To investigate the structural aspects underlying the domain interaction in CDH, hydrogen/deuterium exchange (HDX-MS) with improved proteolytic setup (combination of nepenthesin-1 with rhizopuspepsin), native mass spectrometry with ion mobility and electrostatics calculations were used. HDX-MS revealed pH-dependent changes in solvent accessibility and hydrogen bonding at the interdomain interface. Electrostatics calculations identified these differences to result from charge neutralization by protonation and together with ion mobility pointed at higher electrostatic repulsion between CDH domains at neutral pH. In addition, we uncovered extensive O-glycosylation in the linker region and identified the long-unknown exact cleavage point in papain-mediated domain separation. Transition of CDH between its inactive (open) and interdomain electron transfer-capable (closed) state is shown to be governed by changes in the protein surface electrostatics at the domain interface. Our study confirms that the interdomain electrostatic repulsion is the key factor modulating the functioning of CDH. The results presented in this paper provide experimental evidence for the role of charge repulsion in the interdomain electron transfer in cellobiose dehydrogenases, which is relevant for exploiting their biotechnological potential in biosensors and biofuel cells. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effect of time interval between the second Improvest® dose and slaughter and corn dried distillers grains with solubles feeding strategies on carcass composition, primal cutout, and pork quality of immunologically castrated pigs.

    Science.gov (United States)

    Harris, E K; Mellencamp, M A; Johnston, L J; Cox, R B; Shurson, G C

    2017-05-01

    Effects of dried distillers grains with solubles (DDGS) feeding strategies on carcass composition, primal cutout, and lean quality of immunologically castrated (IC; n=863) pigs were evaluated, and consisted of: 1) corn-soybean meal (CS) diet (PCon); 2) CS+40% DDGS (NCon); 3) CS+40, 30, 20, or 10% DDGS fed in phases 1 to 4, respectively (SD); or 4) CS+40% DDGS fed in phase 1 to 3 and CS in phase 4 (WD). All pigs received the first dose of Improvest® at 11weeks. of age, and the second dose was administered at either 9, 7, or 5weeks. before slaughter at 24weeks. of age. The SD and WD improved carcass dressing percentage and resulted in intermediate primal cut yields and pork loin quality compared with pigs fed PCon and NCon. Increasing the time interval between second dose of Improvest® and slaughter increased adipose tissue accretion but did not affect lean quality of pork. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Nonlinear Flow Generation By Electrostatic Turbulence In Tokamaks

    International Nuclear Information System (INIS)

    Wang, W.X.; Diamond, P.H.; Hahm, T.S.; Ethier, S.; Rewoldt, G.; Tang, W.M.

    2010-01-01

    Global gyrokinetic simulations have revealed an important nonlinear flow generation process due to the residual stress produced by electrostatic turbulence of ion temperature gradient (ITG) modes and trapped electron modes (TEM). In collisionless TEM (CTEM) turbulence, nonlinear residual stress generation by both the fluctuation intensity and the intensity gradient in the presence of broken symmetry in the parallel wave number spectrum is identified for the first time. Concerning the origin of the symmetry breaking, turbulence self-generated low frequency zonal flow shear has been identified to be a key, universal mechanism in various turbulence regimes. Simulations reported here also indicate the existence of other mechanisms beyond E - B shear. The ITG turbulence driven 'intrinsic' torque associated with residual stress is shown to increase close to linearly with the ion temperature gradient, in qualitative agreement with experimental observations in various devices. In CTEM dominated regimes, a net toroidal rotation is driven in the cocurrent direction by 'intrinsic' torque, consistent with the experimental trend of observed intrinsic rotation. The finding of a 'flow pinch' in CTEM turbulence may offer an interesting new insight into the underlying dynamics governing the radial penetration of modulated flows in perturbation experiments. Finally, simulations also reveal highly distinct phase space structures between CTEM and ITG turbulence driven momentum, energy and particle fluxes, elucidating the roles of resonant and non-resonant particles.

  9. Summary of the second international conference on electrostatic accelerator technology

    International Nuclear Information System (INIS)

    Wegner, H.E.

    1977-01-01

    A review is given of the history of electrostatic accelerator technology, including a technology assessment of acceleration tubes, vacuum systems, voltage gradients, charging systems, and ion sources. Improvements in the performance of electrostatic accelerators during the last four years and of those currently under construction are discussed. The improved performance has greatly expanded the heavy ion research capabilities of the entire research community

  10. A Bridge between Two Important Problems in Optics and Electrostatics

    Science.gov (United States)

    Capelli, R.; Pozzi, G.

    2008-01-01

    It is shown how the same physically appealing method can be applied to find analytic solutions for two difficult and apparently unrelated problems in optics and electrostatics. They are: (i) the diffraction of a plane wave at a perfectly conducting thin half-plane and (ii) the electrostatic field associated with a parallel array of stripes held at…

  11. Bidirectional electrostatic linear shuffle motor with two degrees of freedom

    NARCIS (Netherlands)

    Sarajlic, Edin; Berenschot, Johan W.; Fujita, H.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2005-01-01

    We report on an electrostatic linear inchworm micromotor with two translational degrees-of-freedom. The motor employs built-in mechanical leverage to convert normal deflection of a flexible cross-plate into a small in-plane step and four electrostatic clamps to enable bidirectional inchworm motion

  12. Generation of static PET images with [{sup 11}C]-(R)-PK11195: Defining time interval; Geração de imagens PET Estáticas com [{sup 11}C]-(R)-PK11195: definição do intervalo temporal

    Energy Technology Data Exchange (ETDEWEB)

    Schuck, Phelipi Nunes; Dartora, Caroline Machado; Silva, Ana Maria Marques da, E-mail: phelipi.schuck@acad.pucrs.br [Pontificia Universidade catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil). Núcleo de Pesquisa em Imagens Médicas

    2017-07-01

    [{sup 11}C]-(R)-PK11195 radiotracer shows microglia affinity in PET images and can be used as neuro inflammatory disease indicator, such as in Multiple Sclerosis (MS). There is no consensus about appropriate time interval to generate static PET images with [{sup 11}C]-(R)-PK11195. The aim of this study is to define the most appropriate time interval to generate static brain PET images with [{sup 11}C]-(R)-PK11195 for quantification. For this study, images from 10 remittent-recurrent MS patients and 5 healthy controls were used. Static images were generated from list-mode dynamic acquisition in the following time intervals: 0-60min, 5-20min, 5-30min, 10-60min, 30-60min e 40-60min. The ratio between SUV mean of juxtacortical and periventricular regions and normal appearing white matter, denominated SUVR{sup WM}, was used for image quantification. Results shown high variation in time intervals that include radiotracer perfusion. SUVRWM higher stability was observed in two time intervals (30-60min and 40-60min), for both control and MS patients groups. In conclusion, the best acquisition time interval to generate static PET images for quantification is from 40 to 60 minutes after administration, meaning an image acquired 40 minutes after [{sup 11}C]-(R)-PK11195 injection, during 20 min. (author)

  13. Electro-osmosis over inhomogeneously charged surfaces in presence of non-electrostatic ion-ion interactions

    Science.gov (United States)

    Ghosh, Uddipta; Chakraborty, Suman

    2016-06-01

    In this study, we attempt to bring out a generalized formulation for electro-osmotic flows over inhomogeneously charged surfaces in presence of non-electrostatic ion-ion interactions. To this end, we start with modified electro-chemical potential of the individual species and subsequently use it to derive modified Nernst-Planck equation accounting for the ionic fluxes generated because of the presence of non-electrostatic potential. We establish what we refer to as the Poisson-Helmholtz-Nernst-Planck equations, coupled with the Navier-Stokes equations, to describe the complete transport process. Our analysis shows that the presence of non-electrostatic interactions between the ions results in an excess body force on the fluid, and modifies the osmotic pressure as well, which has hitherto remained unexplored. We further apply our analysis to a simple geometry, in an effort to work out the Smoluchowski slip velocity for thin electrical double layer limits. To this end, we employ singular perturbation and develop a general framework for the asymptotic analysis. Our calculations reveal that the final expression for slip velocity remains the same as that without accounting for non-electrostatic interactions. However, the presence of non-electrostatic interactions along with ion specificity can significantly change the quantitative behavior of Smoluchowski slip velocity. We subsequently demonstrate that the presence of non-electrostatic interactions may significantly alter the effective interfacial potential, also termed as the "Zeta potential." Our analysis can potentially act as a guide towards the prediction and possibly quantitative determination of the implications associated with the existence of non-electrostatic potential, in an electrokinetic transport process.

  14. Friction coefficient dependence on electrostatic tribocharging

    Science.gov (United States)

    Burgo, Thiago A. L.; Silva, Cristiane A.; Balestrin, Lia B. S.; Galembeck, Fernando

    2013-01-01

    Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers. PMID:23934227

  15. Friction coefficient dependence on electrostatic tribocharging.

    Science.gov (United States)

    Burgo, Thiago A L; Silva, Cristiane A; Balestrin, Lia B S; Galembeck, Fernando

    2013-01-01

    Friction between dielectric surfaces produces patterns of fixed, stable electric charges that in turn contribute electrostatic components to surface interactions between the contacting solids. The literature presents a wealth of information on the electronic contributions to friction in metals and semiconductors but the effect of triboelectricity on friction coefficients of dielectrics is as yet poorly defined and understood. In this work, friction coefficients were measured on tribocharged polytetrafluoroethylene (PTFE), using three different techniques. As a result, friction coefficients at the macro- and nanoscales increase many-fold when PTFE surfaces are tribocharged, but this effect is eliminated by silanization of glass spheres rolling on PTFE. In conclusion, tribocharging may supersede all other contributions to macro- and nanoscale friction coefficients in PTFE and probably in other insulating polymers.

  16. Electrostatic and magnetic fields in bilayer graphene

    Science.gov (United States)

    Jellal, Ahmed; Redouani, Ilham; Bahlouli, Hocine

    2015-08-01

    We compute the transmission probability through rectangular potential barriers and p-n junctions in the presence of a magnetic and electric fields in bilayer graphene taking into account contributions from the full four bands of the energy spectrum. For energy E higher than the interlayer coupling γ1 (E >γ1) two propagation modes are available for transport giving rise to four possible ways for transmission and reflection coefficients. However, when the energy is less than the height of the barrier the Dirac fermions exhibit transmission resonances and only one mode of propagation is available for transport. We study the effect of the interlayer electrostatic potential denoted by δ and variations of different barrier geometry parameters on the transmission probability.

  17. Electrostatic charge bounds for ball lightning models

    International Nuclear Information System (INIS)

    Stephan, Karl D

    2008-01-01

    Several current theories concerning the nature of ball lightning predict a substantial electrostatic charge in order to account for its observed motion and shape (Turner 1998 Phys. Rep. 293 1; Abrahamson and Dinniss 2000 Nature 403 519). Using charged soap bubbles as a physical model for ball lightning, we show that the magnitude of charge predicted by some of these theories is too high to allow for the types of motion commonly observed in natural ball lightning, which includes horizontal motion above the ground and movement near grounded conductors. Experiments show that at charge levels of only 10-15 nC, 3-cm-diameter soap bubbles tend to be attracted by induced charges to the nearest grounded conductor and rupture. We conclude with a scaling rule that can be used to extrapolate these results to larger objects and surroundings

  18. Electrostatic axisymmetric mirror with removable spherical aberration

    International Nuclear Information System (INIS)

    Birmuzaev, S.B.; Serikbaeva, G.S.; Hizirova, M.A.

    1999-01-01

    The electrostatic axisymmetric mirror, assembled from three coaxial cylinders with an equal diameter d and under the potential v1, v2 and v3, was computed. The proportions of geometrical and electric parameters of the mirror, with which the spherical 3-order aberration may be eliminated, were determined. The computation outcomes of the case, when the focal power of the mirror is enough large and the object plane in the focus is out of its field, are presented (Fig. 1 - potentials proportion that makes elimination of the spherical aberration possible; Fig. 2 - the focus coordinates when the spherical aberration is eliminated). The geometrical values are presented by d, and the electric ones are presented by v1. The figures on the curves present a length of the second (middle) electrode. The zero point is located in the middle of the gap between the first and second electrodes The investigated mirror may be used as a lens for the transmission electron microscope

  19. Obtaining the electrostatic screening from first principles

    International Nuclear Information System (INIS)

    Shaviv, N.J.; Shaviv, G.

    2003-01-01

    We derive the electrostatic screening effect from first principles and show the basic properties of the screening process. We in particular show that under the conditions prevailing in the Sun the number of particles in the Debye sphere is of the order of unity. Consequently; fluctuations play a dominant role in the screening process. The fluctuations lead to an effective time dependent potential. Particles with low kinetic energy lose on the average energy to the plasma and vice versa with high energy particles. We derive general conditions on the screening energy and show under what conditions the Salpeter approximation is obtained. The connection between the screening and relaxation processes in the plasma is exposed

  20. Electrostatically confined quantum rings in bilayer graphene.

    Science.gov (United States)

    Zarenia, M; Pereira, J M; Peeters, F M; Farias, G A

    2009-12-01

    We propose a new system where electron and hole states are electrostatically confined into a quantum ring in bilayer graphene. These structures can be created by tuning the gap of the graphene bilayer using nanostructured gates or by position-dependent doping. The energy levels have a magnetic field (B(0)) dependence that is strikingly distinct from that of usual semiconductor quantum rings. In particular, the eigenvalues are not invariant under a B(0) --> -B(0) transformation and, for a fixed total angular momentum index m, their field dependence is not parabolic, but displays two minima separated by a saddle point. The spectra also display several anticrossings, which arise due to the overlap of gate-confined and magnetically confined states.

  1. DNA under Force: Mechanics, Electrostatics, and Hydration

    Directory of Open Access Journals (Sweden)

    Jingqiang Li

    2015-02-01

    Full Text Available Quantifying the basic intra- and inter-molecular forces of DNA has helped us to better understand and further predict the behavior of DNA. Single molecule technique elucidates the mechanics of DNA under applied external forces, sometimes under extreme forces. On the other hand, ensemble studies of DNA molecular force allow us to extend our understanding of DNA molecules under other forces such as electrostatic and hydration forces. Using a variety of techniques, we can have a comprehensive understanding of DNA molecular forces, which is crucial in unraveling the complex DNA functions in living cells as well as in designing a system that utilizes the unique properties of DNA in nanotechnology.

  2. Electrostatic attraction between overall neutral surfaces.

    Science.gov (United States)

    Adar, Ram M; Andelman, David; Diamant, Haim

    2016-08-01

    Two overall neutral surfaces with positively and negatively charged domains ("patches") have been shown in recent experiments to exhibit long-range attraction when immersed in an ionic solution. Motivated by the experiments, we calculate analytically the osmotic pressure between such surfaces within the Poisson-Boltzmann framework, using a variational principle for the surface-averaged free energy. The electrostatic potential, calculated beyond the linear Debye-Hückel theory, yields an overall attraction at large intersurface separations, over a wide range of the system's controlled length scales. In particular, the attraction is stronger and occurs at smaller separations for surface patches of larger size and charge density. In this large patch limit, we find that the attraction-repulsion crossover separation is inversely proportional to the square of the patch-charge density and to the Debye screening length.

  3. Invited review article: the electrostatic plasma lens.

    Science.gov (United States)

    Goncharov, Alexey

    2013-02-01

    The fundamental principles, experimental results, and potential applications of the electrostatic plasma lens for focusing and manipulating high-current, energetic, heavy ion beams are reviewed. First described almost 50 years ago, this optical beam device provides space charge neutralization of the ion beam within the lens volume, and thus provides an effective and unique tool for focusing high current beams where a high degree of neutralization is essential to prevent beam blow-up. Short and long lenses have been explored, and a lens in which the magnetic field is provided by rare-earth permanent magnets has been demonstrated. Applications include the use of this kind of optical tool for laboratory ion beam manipulation, high dose ion implantation, heavy ion accelerator injection, in heavy ion fusion, and other high technology.

  4. A new electrostatic accelerator: the vivitron

    International Nuclear Information System (INIS)

    1982-07-01

    The 35 MV electrostatic accelerator described in the present document operates according to Van de Graaff tandem type accelerator principles. This new accelerator has appreciable advantages over the classical machines built up to today: 1) reduced radial dimensions, and in consequence, a lower overall cast for identical or even lower limiting electric field values; 2) a significantly reduced stored electrical energy distributed in a homogeneous and better controlled way over the interelectrode space; 3) the use of discrete electrodes rather than classical intermediate screens enabling the advantages of direct electrical vision between the vessel and the high-tension electrode (voltage measurements and regulation by the Corona effect) to be retained. The reduced surface area of these electrodes improving both their characteristics when a voltage is applied and the mechanical behavior of the system; 4) a ''light'' internal structure enabling a horizontal machine to be envisaged [fr

  5. Rapid Quench in an Electrostatic Levitator

    Science.gov (United States)

    SanSoucie, Michael P.; Rogers, Jan R.; Matson, Douglas M.

    2016-01-01

    The Electrostatic Levitation (ESL) Laboratory at the NASA Marshall Space Flight Center (MSFC) is a unique facility for investigators studying high-temperature materials. The ESL laboratory's main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy, as a quench medium. Thereby allowing rapid quenching of undercooled liquid metals. Up to eight quench vessels can be loaded into a wheel inside the chamber that is indexed with control software. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, titanium-zirconium-nickel alloys, and a silicon-cobalt alloy. This new rapid quench system will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and some initial results are presented.

  6. Electrostatic Manipulation of Graphene On Graphite

    Science.gov (United States)

    Untiedt, Carlos; Rubio-Verdu, Carmen; Saenz-Arce, Giovanni; Martinez-Asencio, Jesús; Milan, David C.; Moaied, Mohamed; Palacios, Juan J.; Caturla, Maria Jose

    2015-03-01

    Here we report the use of a Scanning Tunneling Microscope (STM) under ambient and vacuum conditions to study the controlled exfoliation of the last layer of a graphite surface when an electrostatic force is applied from a STM tip. In this work we have focused on the study of two parameters: the applied voltage needed to compensate the graphite interlayer attractive force and the one needed to break atomic bonds to produce folded structures. Additionally, we have studied the influence of edge structure in the breaking geometry. Independently of the edge orientation the graphite layer is found to tear through the zig-zag direction and the lifled layer shows a zig-zag folding direction. Molecular Dinamics simulations and DFT calculations have been performed to understand our results, showing a strong correlation with the experiments. Comunidad Valenciana through Prometeo project.

  7. Characterization of the Electrostatic Environment of Launchers

    Science.gov (United States)

    Soyah, Jamila; Mantion, Pascal; Herlem, Yannick

    2016-05-01

    The purpose of this study was to update knowledge in characterization of the electrostatic environment of launchers in order to be able to propose reductions of design constraints.The first part of this study showed that flashover discharges are the most energetic discharges likely to occur on a launcher. They are mostly due to accumulations of charges by triboelectricity on the external surface of the launcher while flying through clouds containing a lot of small solid particles.Actually flashover discharges are mitigated by limiting the surface's resistance of dielectric materials such as thermal protection set on the external skin of the launcher, thanks to antistatic paints that avoid significant accumulations of charges.But this specified limitation leads to a lot of non- conformances during production phases and, as a result, this leads to additional costs and delays in launches campaigns. That is why on-ground tests have been defined in order to assess the accessibility of a relaxation of those specifications, which would reduce non-conformances.On-ground tests have been carried out, in the second part, on samples of thermal protections covered with antistatic paints with different degraded values of surface resistance. These tests aimed at checking in which conditions a surface discharge can occur in order to deduce a relationship between characteristics of the samples (surface resistance, half-discharge time) and the occurrence of a surface discharge, at ambient pressure and at low pressure.In the third part, in-flight experiments have been defined in order to confirm some hypotheses considered in the study and to assess some parameters in a more accurate way like the incoming charges density per surface unit or the voltage between stages when they get separated, in order to assess more accurately whether the unwinding equalization wire dedicated to maintain the electrostatic balance between stages is necessary or not.

  8. Magnetic and electrostatic confinement of plasma with tuning of electrostatic field

    Science.gov (United States)

    Rostoker, Norman [Irvine, CA; Binderbauer, Michl [Irvine, CA; Qerushi, Artan [Irvine, CA; Tahsiri, Hooshang [Irvine, CA

    2008-10-21

    A system and method for containing plasma and forming a Field Reversed Configuration (FRC) magnetic topology are described in which plasma ions are contained magnetically in stable, non-adiabatic orbits in the FRC. Further, the electrons are contained electrostatically in a deep energy well, created by tuning an externally applied magnetic field. The simultaneous electrostatic confinement of electrons and magnetic confinement of ions avoids anomalous transport and facilitates classical containment of both electrons and ions. In this configuration, ions and electrons may have adequate density and temperature so that upon collisions they are fused together by nuclear force, thus releasing fusion energy. Moreover, the fusion fuel plasmas that can be used with the present confinement system and method are not limited to neutronic fuels only, but also advantageously include advanced fuels.

  9. Electrostatic tuning of permeation and selectivity in aquaporin water channels

    DEFF Research Database (Denmark)

    Jensen, Mogens O Stibius; Tajkhorshid, E.; Schulten, K.

    2003-01-01

    Water permeation and electrostatic interactions between water and channel are investigated in the Escherichia coli glycerol uptake facilitator GlpF, a member of the aquaporin water channel family, by molecular dynamics simulations. A tetrameric model of the channel embedded in a 16:0/ 18:1c9...... with the protein electrostatic fields enforce a bipolar water configuration inside the channel with dipole inversion at the NPA motifs. At the NPA motifs water-protein electrostatic interactions facilitate this inversion. Furthermore, water-water electrostatic interactions are in all regions inside the channel...... stronger than water-protein interactions, except near a conserved, positively charged Arg residue. We find that variations of the protein electrostatic field through the channel, owing to preserved structural features, completely explain the bipolar orientation of water. This orientation persists despite...

  10. Orientation of KRb molecules in a switched electrostatic field

    International Nuclear Information System (INIS)

    Huang Yun-Xia; Xu Shu-Wu; Yang Xiao-Hua

    2013-01-01

    We theoretically investigate the orientation of the cold KRb molecules induced in a switched electrostatic field by numerically solving the full time-dependent Schrödinger equation. The results show that the periodic field-free molecular orientation can be realized for the KRb molecules by rapidly switching off the electrostatic field. Meanwhile, by varying the switching times of the electrostatic field, the adiabatic and nonadiabatic interactions of the molecules with the applied field can be realized. Moreover, the influences of the electrostatic field strength and the rotational temperature to the degree of the molecular orientation are studied. The investigations show that increasing the electrostatic field will increase the degree of the molecular orientation, both in the constant-field regime and in the field-free regime, while the increasing of the rotational temperature of the cold molecules will greatly decrease the degree of the molecular orientation. (atomic and molecular physics)

  11. Molecular dynamics simulations suggest that electrostatic funnel directs binding of Tamiflu to influenza N1 neuraminidases.

    Directory of Open Access Journals (Sweden)

    Ly Le

    2010-09-01

    Full Text Available Oseltamivir (Tamiflu is currently the frontline antiviral drug employed to fight the flu virus in infected individuals by inhibiting neuraminidase, a flu protein responsible for the release of newly synthesized virions. However, oseltamivir resistance has become a critical problem due to rapid mutation of the flu virus. Unfortunately, how mutations actually confer drug resistance is not well understood. In this study, we employ molecular dynamics (MD and steered molecular dynamics (SMD simulations, as well as graphics processing unit (GPU-accelerated electrostatic mapping, to uncover the mechanism behind point mutation induced oseltamivir-resistance in both H5N1 "avian" and H1N1pdm "swine" flu N1-subtype neuraminidases. The simulations reveal an electrostatic binding funnel that plays a key role in directing oseltamivir into and out of its binding site on N1 neuraminidase. The binding pathway for oseltamivir suggests how mutations disrupt drug binding and how new drugs may circumvent the resistance mechanisms.

  12. Magnetic phase transition induced by electrostatic gating in two-dimensional square metal-organic frameworks

    Science.gov (United States)

    Wang, Yun-Peng; Li, Xiang-Guo; Liu, Shuang-Long; Fry, James N.; Cheng, Hai-Ping

    2018-03-01

    We investigate theoretically magnetism and magnetic phase transitions induced by electrostatic gating of two-dimensional square metal-organic framework compounds. We find that electrostatic gating can induce phase transitions between homogeneous ferromagnetic and various spin-textured antiferromagnetic states. Electronic structure and Wannier function analysis can reveal hybridizations between transition-metal d orbitals and conjugated π orbitals in the organic framework. Mn-containing compounds exhibit a strong d -π hybridization that leads to partially occupied spin-minority bands, in contrast to compounds containing transition-metal ions other than Mn, for which electronic structure around the Fermi energy is only slightly spin split due to weak d -π hybridization and the magnetic interaction is of the Ruderman-Kittel-Kasuya-Yosida type. We use a ferromagnetic Kondo lattice model to understand the phase transition in Mn-containing compounds in terms of carrier density and illuminate the complexity and the potential to control two-dimensional magnetization.

  13. 交通拥堵条件下的公交发车间隔过渡模型研究%A Bus Departure Time Interval Transition Model Considering Traffic Congestion

    Institute of Scientific and Technical Information of China (English)

    董红召; 孔娟娟; 刘晴辉

    2016-01-01

    The existing planning models of bus departure time interval usually ignored the important impact factor of real-time traffic congestion. To solve the issue, a departure time interval transition method is presented considering passenger travel demand and traffic congestion. The bus operating hours is divided into several temporary periods separately according to the passenger travel demand and the congestion conditions by the clustering method of samples with sequence. Then these temporary periods are combined to form a period set, in which each period possess the features including passenger travel flow and traffic congestion. Consequently, the departure interval transition model is established to adjust the transient time separately between two neighbor periods to match the passenger travel demand and departure plan. Finally a practical experiment for one bus route in Hangzhou is implemented to verify the proposed model by PARAMICS simulation. The result shows that the model can keep the load ratio in the range of 40%to 70%with the precondition of satisfying the passenger travel demand, and help to improve the service level and the efficiency of the bus transit system.%针对现有公交发车间隔模型忽略了交通拥堵状态对公交运营影响的问题,提出了交通拥堵条件下响应客流需求的发车间隔设计方法。采用有序样本聚类方法,分别根据客流需求及交通拥堵状态对时间段进行聚类划分,并融合处理为若干具有不同客流与拥堵状态综合特征的时间段;分析相邻时段综合特征关系,建立了发车间隔的过渡模型,该模型确定发车时段之间的衔接时长,通过调整衔接时间长度将发车序列在时间轴上平移,弥补交通拥堵造成的客流需求与发车计划匹配错位。最后采用杭州市某线路的运营数据对该模型进行了分析验证,PARAMICS交通仿真实验表明,该模型在满足客流需求的前提下使

  14. Mechanical behavior analysis on electrostatically actuated rectangular microplates

    Science.gov (United States)

    Li, Zhikang; Zhao, Libo; Jiang, Zhuangde; Ye, Zhiying; Dai, Lu; Zhao, Yulong

    2015-03-01

    Microplates are widely used in various MEMS devices based on electrostatic actuation such as MEMS switches, micro pumps and capacitive micromachined ultrasonic transducers (CMUTs). Accurate predictions for the mechanical behavior of the microplate under electrostatic force are important not only for the design and optimization of these electrostatic devices but also for their operation. This paper presents a novel reduced-order model for electrostatically actuated rectangular and square microplates with a new method to treat the nonlinear electrostatic force. The model was developed using Galerkin method which turned the partial-differential equation governing the microplates into an ordinary equation system. Using this model and cosine-like deflection functions, explicit expressions were established for the deflection and pull-in voltage of the rectangular and square microplates. The theoretical results were well validated with the finite element method simulations and experimental data of literature. The expressions for the deflection analysis are able to predict the deflection up to the pull-in position with an error less than 5.0%. The expressions for the pull-in voltage analysis can determine the pull-in voltages with errors less than 1.0%. Additionally, the method to calculate the capacitance variation of the electrostatically actuated microplates was proposed. These theoretical analyses are helpful for design and optimization of electrostatically actuated microdevices.

  15. Mechanical behavior analysis on electrostatically actuated rectangular microplates

    International Nuclear Information System (INIS)

    Li, Zhikang; Zhao, Libo; Jiang, Zhuangde; Ye, Zhiying; Zhao, Yulong; Dai, Lu

    2015-01-01

    Microplates are widely used in various MEMS devices based on electrostatic actuation such as MEMS switches, micro pumps and capacitive micromachined ultrasonic transducers (CMUTs). Accurate predictions for the mechanical behavior of the microplate under electrostatic force are important not only for the design and optimization of these electrostatic devices but also for their operation. This paper presents a novel reduced-order model for electrostatically actuated rectangular and square microplates with a new method to treat the nonlinear electrostatic force. The model was developed using Galerkin method which turned the partial-differential equation governing the microplates into an ordinary equation system. Using this model and cosine-like deflection functions, explicit expressions were established for the deflection and pull-in voltage of the rectangular and square microplates. The theoretical results were well validated with the finite element method simulations and experimental data of literature. The expressions for the deflection analysis are able to predict the deflection up to the pull-in position with an error less than 5.0%. The expressions for the pull-in voltage analysis can determine the pull-in voltages with errors less than 1.0%. Additionally, the method to calculate the capacitance variation of the electrostatically actuated microplates was proposed. These theoretical analyses are helpful for design and optimization of electrostatically actuated microdevices. (paper)

  16. Competing processes of whistler and electrostatic instabilities in the magnetosphere

    International Nuclear Information System (INIS)

    Omura, Y.; Matsumoto, H.

    1987-01-01

    Competing processes of whistler mode and electrostatic mode instabilities induced by an electron beam are studied by a linear growth rate analysis and by an electromagnetic particle simulation. In addition to a background cold plasma we assumed an electron beam drifting along a static magnetic field. We studied excitation of whistler and electrostatic mode waves in the direction of the static magnetic field. We first calculated linear growth rates for the whistler mode and electrostatic mode instabilities, assuming various possible parameters in the equatorial magnetosphere. We found that the growth rate for the electrostatic instability is always larger than that of the whistler mode instability. A short simulation run with a monoenergetic electron beam demonstrates that a monoenergetic beam can hardly give energy to whistler mode waves as a result of competition with faster growing electrostatic waves, because the beam electrons are trapped and diffused by the electrostatic waves, and hence the growth rates for whistler mode waves become very small. A long simulation run starting with a warm electron beam demonstrates that whistler mode waves are excited in spite of the small growth rates and the coexisting quasi-linear electrostatic diffusion process

  17. Conservation and Role of Electrostatics in Thymidylate Synthase.

    Science.gov (United States)

    Garg, Divita; Skouloubris, Stephane; Briffotaux, Julien; Myllykallio, Hannu; Wade, Rebecca C

    2015-11-27

    Conservation of function across families of orthologous enzymes is generally accompanied by conservation of their active site electrostatic potentials. To study the electrostatic conservation in the highly conserved essential enzyme, thymidylate synthase (TS), we conducted a systematic species-based comparison of the electrostatic potential in the vicinity of its active site. Whereas the electrostatics of the active site of TS are generally well conserved, the TSs from minimal organisms do not conform to the overall trend. Since the genomes of minimal organisms have a high thymidine content compared to other organisms, the observation of non-conserved electrostatics was surprising. Analysis of the symbiotic relationship between minimal organisms and their hosts, and the genetic completeness of the thymidine synthesis pathway suggested that TS from the minimal organism Wigglesworthia glossinidia (W.g.b.) must be active. Four residues in the vicinity of the active site of Escherichia coli TS were mutated individually and simultaneously to mimic the electrostatics of W.g.b TS. The measured activities of the E. coli TS mutants imply that conservation of electrostatics in the region of the active site is important for the activity of TS, and suggest that the W.g.b. TS has the minimal activity necessary to support replication of its reduced genome.

  18. Stability, Nonlinearity and Reliability of Electrostatically Actuated MEMS Devices

    Directory of Open Access Journals (Sweden)

    Di Chen

    2007-05-01

    Full Text Available Electrostatic micro-electro-mechanical system (MEMS is a special branch with a wide range of applications in sensing and actuating devices in MEMS. This paper provides a survey and analysis of the electrostatic force of importance in MEMS, its physical model, scaling effect, stability, nonlinearity and reliability in detail. It is necessary to understand the effects of electrostatic forces in MEMS and then many phenomena of practical importance, such as pull-in instability and the effects of effective stiffness, dielectric charging, stress gradient, temperature on the pull-in voltage, nonlinear dynamic effects and reliability due to electrostatic forces occurred in MEMS can be explained scientifically, and consequently the great potential of MEMS technology could be explored effectively and utilized optimally. A simplified parallel-plate capacitor model is proposed to investigate the resonance response, inherent nonlinearity, stiffness softened effect and coupled nonlinear effect of the typical electrostatically actuated MEMS devices. Many failure modes and mechanisms and various methods and techniques, including materials selection, reasonable design and extending the controllable travel range used to analyze and reduce the failures are discussed in the electrostatically actuated MEMS devices. Numerical simulations and discussions indicate that the effects of instability, nonlinear characteristics and reliability subjected to electrostatic forces cannot be ignored and are in need of further investigation.

  19. Impact of Electrostatic Assist on Halftone Mottle in Shrink Films

    Directory of Open Access Journals (Sweden)

    Akshay V. Joshi

    2015-09-01

    Full Text Available Gravure printing delivers intricate print quality and exhibit better feasibility for printing long run packaging jobs. PVC and PETG are widely used shrink films printed by gravure process. The variation in ink transfer from gravure cells on to the substrate results in print mottle. The variation is inevitable and requires close monitoring with tight control on process parameters to deliver good dot fidelity. The electrostatic assist in gravure improves the ink transfer efficiency but is greatly influenced by ESA parameters such as air gap (distance between charge bar and impression roller and voltage. Moreover, it is imperative to study the combined effect of ESA and gravure process parameters such as line screen, viscosity and speed for the minimization of half-tone mottle in shrink films. A general full factorial design was performed for the above mentioned parameters to evaluate half-tone mottle. The significant levels of both the main and interactions were studied by ANOVA approach. The statistical analysis revealed the significance of all the process parameters with viscosity, line screen and voltage being the major contributors in minimization of half-tone mottle. The optimized setting showed reduction in halftone mottle by 33% and 32% for PVC and PET-G respectively. The developed regression model was tested that showed more than 95% predictability. Furthermore, the uniformity of dot was measured by image to non-image area (ratio distribution. The result showed reduction in halftone mottle with uniform dot distribution.

  20. Application of Electrostatic Extrusion - Flavour Encapsulation and Controlled Release.

    Science.gov (United States)

    Manojlovic, Verica; Rajic, Nevenka; Djonlagic, Jasna; Obradovic, Bojana; Nedovic, Viktor; Bugarski, Branko

    2008-03-03

    The subject of this study was the development of flavour alginate formulationsaimed for thermally processed foods. Ethyl vanilline was used as the model flavourcompound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline inalginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethylvanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about450 μm. Chemical characterization by H-NMR spectroscopy revealed that the alginateused in this study had a high content (67 %) of guluronic residues and was rich in GG diadblocks (FGG = 55%) and thus presented a high-quality immobilisation matrix. The thermalbehaviour of alginate beads encapsulating ethyl vanilline was investigated bythermogravimetric (TG) and differential scanning calorimetry measurements (TG-DSC)under heating conditions which mimicked usual food processing to provide informationabout thermal decomposition of alginate matrix and kinetics of aroma release. Two wellresolved weight losses were observed. The first one was in the 50-150 °C temperaturerange with the maximum at approx. 112 °C, corresponding to the dehydration of thepolymer network. The second loss in the 220-325 °C temperature range, with a maximumat ~ 247 °C corresponded to the release of vanilline. The obtained results indicate that up to230 °C most of the vanilline remained intacta, while prolonged heating at elevatedtemperatures led to the entire loss of the aroma compound.

  1. Application of Electrostatic Extrusion – Flavour Encapsulation and Controlled Release

    Science.gov (United States)

    Manojlovic, Verica; Rajic, Nevenka; Djonlagic, Jasna; Obradovic, Bojana; Nedovic, Viktor; Bugarski, Branko

    2008-01-01

    The subject of this study was the development of flavour alginate formulations aimed for thermally processed foods. Ethyl vanilline was used as the model flavour compound. Electrostatic extrusion was applied for the encapsulation of ethyl vanilline in alginate gel microbeads. The obtained microbeads with approx. 10 % w/w of ethyl vanilline encapsulated in about 2 % w/w alginate were uniformly sized spheres of about 450 μm. Chemical characterization by H-NMR spectroscopy revealed that the alginate used in this study had a high content (67 %) of guluronic residues and was rich in GG diad blocks (FGG = 55%) and thus presented a high-quality immobilisation matrix. The thermal behaviour of alginate beads encapsulating ethyl vanilline was investigated by thermogravimetric (TG) and differential scanning calorimetry measurements (TG-DSC) under heating conditions which mimicked usual food processing to provide information about thermal decomposition of alginate matrix and kinetics of aroma release. Two well resolved weight losses were observed. The first one was in the 50-150 °C temperature range with the maximum at approx. 112 °C, corresponding to the dehydration of the polymer network. The second loss in the 220-325 °C temperature range, with a maximum at ∼ 247 °C corresponded to the release of vanilline. The obtained results indicate that up to 230 °C most of the vanilline remained intacta, while prolonged heating at elevated temperatures led to the entire loss of the aroma compound. PMID:27879775

  2. Improvement of the voltage properties of the Fermilab electrostatic septa

    International Nuclear Information System (INIS)

    Trbojevic, D.; Crawford, C.; Childress, S.; Tinsely, D.

    1985-01-01

    In the Fermilab Tevatron Switchyard proton beam splits are initiated by a wire array electrostatic septum. At 1 TeV energy, and with fields limited to 50 kV/cm, and electrostatic septum more than 20 meters in length is required to produce the required angular separation between the beams for the Proton and Neutrino/Meson lines. New techniques have been investigated that will allow reliable operation at fields above 75 kV/cm with resultant beam line economy. Changes in construction and conditioning procedures have been studied using a short sample of an electrostatic septum

  3. Electrostatically Induced Carbon Nanotube Alignment for Polymer Composite Applications

    Science.gov (United States)

    Chapkin, Wesley Aaron

    We have developed a non-invasive technique utilizing polarized Raman spectroscopy to measure changes in carbon nanotube (CNT) alignment in situ and in real time in a polymer matrix. With this technique, we have confirmed the prediction of faster alignment for CNTs in higher electric fields. Real-time polarized Raman spectroscopy also allows us to demonstrate the loss of CNT alignment that occurs after the electric field is removed, which reveals the need for fast polymerization steps or the continued application of the aligning force during polymerization to lock in CNT alignment. Through a study on the effect of polymer viscosity on the rate of CNT alignment, we have determined that shear viscosity serves as the controlling mechanism for CNT rotation. This finding matches literature modeling of rigid rod mobility in a polymer melt and demonstrates that the rotational mobility of CNTs can be explained by a continuum model even though the diameters of single-walled CNTs are 1-2 nm. The viscosity dependence indicates that the manipulation of temperature (and indirectly viscosity) will have a direct effect on the rate of CNT alignment, which could prove useful in expediting the manufacturing of CNT-reinforced composites cured at elevated temperatures. Using real-time polarized Raman spectroscopy, we also demonstrate that electric fields of various strengths lead not only to different speeds of CNT rotation but also to different degrees of alignment. We hypothesize that this difference in achievable alignment results from discrete populations of nanotubes based on their length. The results are then explained by balancing the alignment energy for a given electric field strength with the randomizing thermal energy of the system. By studying the alignment dynamics of different CNT length distributions, we show that different degrees of alignment achieved as a function of the applied electric field strength are directly related to the square of the nanotube length. This

  4. Ultrahigh impedance method to assess electrostatic accelerator performance

    Directory of Open Access Journals (Sweden)

    Nikolai R. Lobanov

    2015-06-01

    Full Text Available This paper describes an investigation of problem-solving procedures to troubleshoot electrostatic accelerators. A novel technique to diagnose issues with high-voltage components is described. The main application of this technique is noninvasive testing of electrostatic accelerator high-voltage grading systems, measuring insulation resistance, or determining the volume and surface resistivity of insulation materials used in column posts and acceleration tubes. In addition, this technique allows verification of the continuity of the resistive divider assembly as a complete circuit, revealing if an electrical path exists between equipotential rings, resistors, tube electrodes, and column post-to-tube conductors. It is capable of identifying and locating a “microbreak” in a resistor and the experimental validation of the transfer function of the high impedance energy control element. A simple and practical fault-finding procedure has been developed based on fundamental principles. The experimental distributions of relative resistance deviations (ΔR/R for both accelerating tubes and posts were collected during five scheduled accelerator maintenance tank openings during 2013 and 2014. Components with measured ΔR/R>±2.5% were considered faulty and put through a detailed examination, with faults categorized. In total, thirty four unique fault categories were identified and most would not be identifiable without the new technique described. The most common failure mode was permanent and irreversible insulator current leakage that developed after being exposed to the ambient environment. As a result of efficient in situ troubleshooting and fault-elimination techniques, the maximum values of |ΔR/R| are kept below 2.5% at the conclusion of maintenance procedures. The acceptance margin could be narrowed even further by a factor of 2.5 by increasing the test voltage from 40 V up to 100 V. Based on experience over the last two years, resistor and

  5. Present status of TIARA electrostatic accelerator facility

    Energy Technology Data Exchange (ETDEWEB)

    Tajima, Satoshi; Takada, Isao; Mizuhashi, Kiyoshi; Saito, Yuichi; Uno, Sadanori; Okoshi, Kiyonori; Ishii, Yasuyuki; Nakajima, Yoshinori; Sakai, Takuro [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    1996-12-01

    The electrostatic accelerator, 3 MV tandem accelerator, 3 MV single end accelerator and 400 kV ion implantation equipment, which were installed in Takasaki Ion Irradiation Research Facility (TIARA) of Japan Atomic Energy Research Institute, have been used for the research on the advanced utilization of radiation mainly in material science by ion beam. The utilization is open to other researchers, and in fiscal year 1995, about 40% was the utilization by outsiders. The number of the experimental subjects adopted in fiscal year 1995 was 47, and the fields of research were space and environment materials, nuclear fusion reactor materials, new functional materials, biotechnology and base technology. The operation time in fiscal year 1995 was 1201, 1705 and 1505 hours for the tandem accelerator, single end accelerator and ion implantation equipment, respectively. The methods of experiment are reported. The troubles occurred in the tandem accelerator and single end accelerator are reported. As the diversification of beam utilization in the tandem accelerator, the utilizations of high energy molecular ions, low energy negative ions, multivalent ions by post stripper and low intensity ions by mesh attenuator have been attempted. These utilizations are described. (K.I.)

  6. Electrostatic fluctuation in Low-{beta} plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krane, B

    1997-11-01

    The thesis gives an overview, which by no means is complete, to two dimensional plasma flows. The plasma is taken to be strongly magnetized such that magnetic fields generated by internal currents are small compared to the background magnetic field. This requires that the magnetic pressure exerted by the ambient magnetic field is large compared to the pressure due to thermal fluctuations, i.e. low-{beta} plasma. The author also assume low frequency electrostatic fluctuations with {omega}<<{omega}{sub c}i where {omega}{sub c}i is the ion gyro frequency. A brief introduction to nonlinear phenomena in two dimensional plasma flows has been presented. Particular attention was given to simple models describing flute and drift modes. Although the derivations of the model equations are based on different assumptions regarding the plasma conditions, the resulting equations exhibit similar behavior in some respects. For instance, both the simple guiding center model and the Hasegawa-Mima model have stable dipolar structures. The inverse cascade was also found in both models. However, it is evident that there are significant differences, first of all the Hasegawa-Mima model assumes a background density gradient which makes it an inhomogeneous model. Secondly, in this model the electrons respond instantaneously to variations in the ion density by moving along the magnetic field, thereby introducing Debye shielding.

  7. Electrostatic interactions in aqueous solutions of polyelectrolyte

    International Nuclear Information System (INIS)

    Belloni, Luc

    1982-01-01

    In this study, the structure, equilibrium and transport properties of poly-electrolytes solutions are reported. These dissymmetric systems are studied in the context of a primitive model (Charged hard spheres and rods in a solvent continuum). The first phenomenon studied is the strong electrostatic attractive interaction of counterions on the poly-ion surface. The model used considers the poly-ions on a matrix and the different concentrations are calculated using the P.B. equation. Auto-diffusion coefficients obtained give a good description of experimental slowing down of the counterions. The model allows a correlation between the theoretical limits represented by Bjerrum's and Manning's models and gives a physical significance to the concept of condensation. In the second part, the complete structure is calculated using only slightly restrictive H.N.C. approximation. This theory enables all the pair correlation functions to be calculated as well as thermodynamic data and structure factors. The last part of this study treats transport phenomena. Quasi-elastic light scattering gives information on the autocorrelation function of the scattered light intensity. Analysis using cumulants leads to an effective diffusion coefficient which is theoretically related to the structure factor and the hydrodynamic interactions. A crude approximation of the last contribution allows to fit the experimental data. (author) [fr

  8. Radioisotope detection with tandem electrostatic accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Gove, H E; Elmore, D; Ferraro, R [Rochester Univ., NY (USA). Nuclear Structure Research Lab.; Beukens, R P; Chang, K H; Kilius, L R; Lee, H W; Litherland, A E [Toronto Univ., Ontario (Canada). Dept. of Physics; Purser, K H [General Ionex Corp., Newburyport, MA (USA)

    1980-01-01

    An MP tandem Van de Graaff accelerator at the University of Rochester has been employed since May 1977 to detect /sup 14/C in terrestrial samples, /sup 36/Cl in terrestrial and extraterrestrial samples and /sup 10/Be and /sup 26/Al in samples produced by reactor and accelerator irradiation. The sample sizes ranged from about 10 to less than 1 mg and the ratio of the radioisotope to the stable isotopes approached one part in 10/sup 16/ for /sup 14/C and /sup 36/Cl and one part in 10/sup 14/ for /sup 10/Be and /sup 26/Al. /sup 14/C has been measured in a number of samples of geological and archaelogical interest. /sup 36/Cl has been measured in various groundwater samples as well as samples at Antarctic meteorites and ice. Dedicated systems for /sup 14/C dating and geological measurements based on the tandem electrostatic accelerator principle are presently under construction for laboratories in the U.S.A., U.K. and Canada.

  9. Electrostatic turbulence in the Z pinch corona

    International Nuclear Information System (INIS)

    Terry, R.E.

    1994-01-01

    The microstability of electrostatic waves in the periphery of a Z pinch is formulated and resolved for a new class of Vlasov meta-equilibria admitting self-similar solutions in the electron gyrokinetic limit. These equilibria are subject to strong radial motions, and a mild deviation from charge neutrality arises to maintain ion acceleration close to that of the magnetized electrons. A unique class of profiles in density, axial current, temperature, and drift speed defines these equilibria. They are characterized by (i) the interior pinch current, (ii) the interior number density, (iii) the parallel and perpendicular temperatures, (iv) the exterior axial electric field value at the initial time, and (v) the radial ion acceleration relative to that of the electrons. Unstable ion sound waves arise in this medium by coupling radial and axial free energy to azimuthal longitudinal oscillations. The waves grow only for a limited range of radial or axial Exb/B drift speeds and electron temperatures. The growth rate, which can be as large as 0.115ω pi , is found to scale proportional to plasma frequency over the density range from 10 12 to 10 18 ions cm -3

  10. Heliopause Electrostatic Rapid Transit System (HERTS)

    Science.gov (United States)

    Wiegmann, Bruce M.

    2015-01-01

    A recent six month investigation focused on: "Determining the benefits of propelling a scientific spacecraft by an 'Electric Sail' propulsion system to the edge of our solar system (the Heliopause), a distance of 100 to 120 AU, in ten years or less" has recently been completed by the Advance Concepts Office at NASA's MSFC. The concept investigated has been named the Heliopause Electrostatic Rapid Transit System (HERTS) by the MSFC team. The HERTS is a revolutionary propellant-less propulsion concept that is ideal for deep space missions to the Outer Planets, Heliopause, and beyond. It is unique in that it uses momentum exchange from naturally occurring solar wind protons to propel a spacecraft within the heliosphere. The propulsion system consists of an array of electrically positively-biased wires that extend outward 20 km from a rotating (one revolution per hour) spacecraft. It was determined that the HERTS system can accelerate a spacecraft to velocities as much as two to three times that possible by any realistic extrapolation of current state-of-the-art propulsion technologies- including solar electric and solar sail propulsion systems. The data produced show that a scientific spacecraft could reach distances of 100AU in less than 10 years. Moreover, it can be reasonably expected that this system could be developed within a decade and provide meaningful Heliophysics Science and Outer Planetary Science returns in the 2025-2035 timeframe.

  11. MSFC Electrostatic Levitator (ESL) Rapid Quench System

    Science.gov (United States)

    SanSoucie, Michael P.; Craven, Paul D.; Rogers, Jan R.

    2014-01-01

    The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) Laboratory is a unique facility for investigators studying high-temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified, all without the interference of a container or data-gathering instrument. The ESL main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy. Thereby allowing rapid quenching of undercooled liquid metals. Up to 8 quench vessels can be loaded into the quench wheel, which is indexed with LabVIEW control software. This allows up to 8 samples to be rapidly quenched before having to open the chamber. The system has been tested successfully on several zirconium samples. Future work will be done with other materials using different quench mediums. Microstructural analysis will also be done on successfully quench samples.

  12. Electrostatically actuated resonant switches for earthquake detection

    KAUST Repository

    Ramini, Abdallah H.

    2013-04-01

    The modeling and design of electrostatically actuated resonant switches (EARS) for earthquake and seismic applications are presented. The basic concepts are based on operating an electrically actuated resonator close to instability bands of frequency, where it is forced to collapse (pull-in) if operated within these bands. By careful tuning, the resonator can be made to enter the instability zone upon the detection of the earthquake signal, thereby pulling-in as a switch. Such a switching action can be functionalized for useful functionalities, such as shutting off gas pipelines in the case of earthquakes, or can be used to activate a network of sensors for seismic activity recording in health monitoring applications. By placing a resonator on a printed circuit board (PCB) of a natural frequency close to that of the earthquake\\'s frequency, we show significant improvement on the detection limit of the EARS lowering it considerably to less than 60% of the EARS by itself without the PCB. © 2013 IEEE.

  13. Electrostatic fluctuation in Low-β plasmas

    International Nuclear Information System (INIS)

    Krane, B

    1997-11-01

    The thesis gives an overview, which by no means is complete, to two dimensional plasma flows. The plasma is taken to be strongly magnetized such that magnetic fields generated by internal currents are small compared to the background magnetic field. This requires that the magnetic pressure exerted by the ambient magnetic field is large compared to the pressure due to thermal fluctuations, i.e. low-β plasma. The author also assume low frequency electrostatic fluctuations with ω c i where ω c i is the ion gyro frequency. A brief introduction to nonlinear phenomena in two dimensional plasma flows has been presented. Particular attention was given to simple models describing flute and drift modes. Although the derivations of the model equations are based on different assumptions regarding the plasma conditions, the resulting equations exhibit similar behavior in some respects. For instance, both the simple guiding center model and the Hasegawa-Mima model have stable dipolar structures. The inverse cascade was also found in both models. However, it is evident that there are significant differences, first of all the Hasegawa-Mima model assumes a background density gradient which makes it an inhomogeneous model. Secondly, in this model the electrons respond instantaneously to variations in the ion density by moving along the magnetic field, thereby introducing Debye shielding

  14. Electrostatic bending response of a charged helix

    Science.gov (United States)

    Zampetaki, A. V.; Stockhofe, J.; Schmelcher, P.

    2018-04-01

    We explore the electrostatic bending response of a chain of charged particles confined on a finite helical filament. We analyze how the energy difference Δ E between the bent and the unbent helical chain scales with the length of the helical segment and the radius of curvature and identify features that are not captured by the standard notion of the bending rigidity, normally used as a measure of bending tendency in the linear response regime. Using Δ E to characterize the bending response of the helical chain we identify two regimes with qualitatively different bending behaviors for the ground state configuration: the regime of small and the regime of large radius-to-pitch ratio, respectively. Within the former regime, Δ E changes smoothly with the variation of the system parameters. Of particular interest are its oscillations with the number of charged particles encountered for commensurate fillings which yield length-dependent oscillations in the preferred bending direction of the helical chain. We show that the origin of these oscillations is the nonuniformity of the charge distribution caused by the long-range character of the Coulomb interactions and the finite length of the helix. In the second regime of large values of the radius-to-pitch ratio, sudden changes in the ground state structure of the charges occur as the system parameters vary, leading to complex and discontinuous variations in the ground state bending response Δ E .

  15. Electrostatic turbulence in the Tokamak TBR-1

    International Nuclear Information System (INIS)

    Castro, R.M. de.

    1991-01-01

    Characteristics of turbulence at plasma edge of tokamak TBR - 1 are determined from measurements of potentials and density fluctuations, done with a square array of four single Langmuir probes. Two adjacent probes are used to measure the floating potential of the plasma in either poloidal or toroidal directions, the remaining two probes are used to measure saturation current also in poloidal and toroidal directions. Using multiple shot data from the four probe array the radial fluctuation density (n ∼ ) and floating potential (φ ∼ ) profiles are estimated. Analysing the fluctuations spectra the wavenumber-frequency spectrum S(k,ω) from two points measurements is determined. An extension of the cross-correlation concept to a three points correlations leads to the estimation of the fluctuation induced particle flux, from which the particle diffusion coefficient and the convected heat flux can be estimated. All this measurements were performed with and without a resonant magnetic field to verify the eventual influence of this field on the data already mentioned. It was verified that the particle flux is outward and due to electrostatic fluctuations with frequencies lower than 150 khz. (author)

  16. Feedback stabilization of electrostatic reactive instabilities

    International Nuclear Information System (INIS)

    Richards, R.K.

    1976-01-01

    A general theory for the feedback stabilization of electrostatic reactive instabilities is developed which includes the effects of dissipation in the plasma and frequency dependence in the sensor-suppressor elements and in the external feedback circuit. This theory is compared to experiments involving particular reactive instability, an interchange mode, found in a magnetic mirror device; these results are found to be in good agreement with theory. One noteworthy result is that a frequency dependence in the overall gain and phase shift of the feedback loop can cause destabilization at large gain. Multimode feedback stabilization is studied using the spatial variation of two interchange modes to separate them such that each can be acted upon individually by the feedback system. The transfer function of the plasma is also examined. This analysis is used for mode identification and location of the pole positions. As an example of using feedback as a diagnostic tool, instability induced transport is studied. Here feedback is used to control the amplitude of fluctuations at saturation

  17. Multipolar electrostatics for proteins: atom-atom electrostatic energies in crambin.

    Science.gov (United States)

    Yuan, Yongna; Mills, Matthew J L; Popelier, Paul L A

    2014-02-15

    Accurate electrostatics necessitates the use of multipole moments centered on nuclei or extra point charges centered away from the nuclei. Here, we follow the former alternative and investigate the convergence behavior of atom-atom electrostatic interactions in the pilot protein crambin. Amino acids are cut out from a Protein Data Bank structure of crambin, as single amino acids, di, or tripeptides, and are then capped with a peptide bond at each side. The atoms in the amino acids are defined through Quantum Chemical Topology (QCT) as finite volume electron density fragments. Atom-atom electrostatic energies are computed by means of a multipole expansion with regular spherical harmonics, up to a total interaction rank of L = ℓA+ ℓB + 1 = 10. The minimum internuclear distance in the convergent region of all the 15 possible types of atom-atom interactions in crambin that were calculated based on single amino acids are close to the values calculated from di and tripeptides. Values obtained at B3LYP/aug-cc-pVTZ and MP2/aug-cc-pVTZ levels are only slightly larger than those calculated at HF/6-31G(d,p) level. This convergence behavior is transferable to the well-known amyloid beta polypeptide Aβ1-42. Moreover, for a selected central atom, the influence of its neighbors on its multipole moments is investigated, and how far away this influence can be ignored is also determined. Finally, the convergence behavior of AMBER becomes closer to that of QCT with increasing internuclear distance. Copyright © 2013 Wiley Periodicals, Inc.

  18. Charged patchy particle models in explicit salt: Ion distributions, electrostatic potentials, and effective interactions.

    Science.gov (United States)

    Yigit, Cemil; Heyda, Jan; Dzubiella, Joachim

    2015-08-14

    We introduce a set of charged patchy particle models (CPPMs) in order to systematically study the influence of electrostatic charge patchiness and multipolarity on macromolecular interactions by means of implicit-solvent, explicit-ion Langevin dynamics simulations employing the Gromacs software. We consider well-defined zero-, one-, and two-patched spherical globules each of the same net charge and (nanometer) size which are composed of discrete atoms. The studied mono- and multipole moments of the CPPMs are comparable to those of globular proteins with similar size. We first characterize ion distributions and electrostatic potentials around a single CPPM. Although angle-resolved radial distribution functions reveal the expected local accumulation and depletion of counter- and co-ions around the patches, respectively, the orientation-averaged electrostatic potential shows only a small variation among the various CPPMs due to space charge cancellations. Furthermore, we study the orientation-averaged potential of mean force (PMF), the number of accumulated ions on the patches, as well as the CPPM orientations along the center-to-center distance of a pair of CPPMs. We compare the PMFs to the classical Derjaguin-Verwey-Landau-Overbeek theory and previously introduced orientation-averaged Debye-Hückel pair potentials including dipolar interactions. Our simulations confirm the adequacy of the theories in their respective regimes of validity, while low salt concentrations and large multipolar interactions remain a challenge for tractable theoretical descriptions.

  19. Electrostatic Origin of the Red Solvatochromic Shift of DFHBDI in RNA Spinach.

    Science.gov (United States)

    Bose, Samik; Chakrabarty, Suman; Ghosh, Debashree

    2017-05-11

    Interactions with the environment tune the spectral properties of biological chromophores, e.g., fluorescent proteins. Understanding the relative contribution of the various types of noncovalent interactions in the spectral shifts can provide rational design principles toward developing new fluorescent probes. In this work, we investigate the origin of the red shift in the absorption spectra of the difluoro hydroxybenzylidene dimethyl imidazolinone (DFHBDI) chromophore in RNA spinach as compared to the aqueous solution. We systematically decompose the effects of various components of interactions, namely, stacking, hydrogen bonding, and long-range electrostatics, in order to elucidate the relative role of these interactions in the observed spectral behavior. We find that the absorption peak of DFHBDI is red-shifted by ∼0.35 eV in RNA relative to the aqueous solution. Earlier proposals from Huang and co-workers have implicated the stacking interactions between DFHBDI and nucleic acid bases to be the driving force behind the observed red shift. In contrast, our findings reveal that the long-range electrostatic interactions between DFHBDI and negatively charged RNA make the most significant contribution. Moreover, we notice that the opposing electrostatic fields due to the RNA backbone and the polarized water molecules around the RNA give rise to the resultant red shift. Our results emphasize the effect of strong heterogeneity in the various environmental factors that might be competing with each other.

  20. Electrostatic atomization--Experiment, theory and industrial applications

    Science.gov (United States)

    Okuda, H.; Kelly, Arnold J.

    1996-05-01

    Experimental and theoretical research has been initiated at the Princeton Plasma Physics Laboratory on the electrostatic atomization process in collaboration with Charged Injection Corporation. The goal of this collaboration is to set up a comprehensive research and development program on the electrostatic atomization at the Princeton Plasma Physics Laboratory so that both institutions can benefit from the collaboration. Experimental, theoretical and numerical simulation approaches are used for this purpose. An experiment consisting of a capillary sprayer combined with a quadrupole mass filter and a charge detector was installed at the Electrostatic Atomization Laboratory to study fundamental properties of the charged droplets such as the distribution of charges with respect to the droplet radius. In addition, a numerical simulation model is used to study interaction of beam electrons with atmospheric pressure water vapor, supporting an effort to develop an electrostatic water mist fire-fighting nozzle.

  1. Ballistic Jumping Drops on Superhydrophobic Surfaces via Electrostatic Manipulation.

    Science.gov (United States)

    Li, Ning; Wu, Lei; Yu, Cunlong; Dai, Haoyu; Wang, Ting; Dong, Zhichao; Jiang, Lei

    2018-02-01

    The ballistic ejection of liquid drops by electrostatic manipulating has both fundamental and practical implications, from raindrops in thunderclouds to self-cleaning, anti-icing, condensation, and heat transfer enhancements. In this paper, the ballistic jumping behavior of liquid drops from a superhydrophobic surface is investigated. Powered by the repulsion of the same kind of charges, water drops can jump from the surface. The electrostatic acting time for the jumping of a microliter supercooled drop only takes several milliseconds, even shorter than the time for icing. In addition, one can control the ballistic jumping direction precisely by the relative position above the electrostatic field. The approach offers a facile method that can be used to manipulate the ballistic drop jumping via an electrostatic field, opening the possibility of energy efficient drop detaching techniques in various applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. An electrostatic RF modulator for Moessbauer gamma-rays

    International Nuclear Information System (INIS)

    Ognjanov, N.I.; Tsankov, L.T.; Ivanov, P.V.

    1983-01-01

    A new device is proposed for rf acoustic modulation of Moessbauer gamma-radiation, based on the principle of the electrostatic speaker. Certain features of the construction are discussed and results from tests are presented. (orig.)

  3. Nonlinear Mechanics of MEMS Rectangular Microplates under Electrostatic Actuation

    KAUST Repository

    Saghir, Shahid

    2016-01-01

    The first objective of the dissertation is to develop a suitable reduced order model capable of investigating the nonlinear mechanical behavior of von-Karman plates under electrostatic actuation. The second objective is to investigate the nonlinear

  4. Stability of dispersions in polar organic media. I. Electrostatic stabilization

    NARCIS (Netherlands)

    Rooy, N. de; Bruyn, P.L. de; Overbeek, J.Th.G.

    Electrostatically stabilized sols of silver, silver iodide, α-goethite, and copper phthalocyanine in methanol, ethanol, isopropanol, and acetone have been prepared and characterized. Coagulation concentrations with electrolytes of various charge numbers have been determined in water, in organic

  5. Dissolution of heavy metals from electrostatic precipitator (ESP) dust ...

    African Journals Online (AJOL)

    SIBOO

    Key words: Fungal leaching, sponge iron, electrostatic precipitator (ESP) dust, metal dissolution. INTRODUCTION ... ability of micro organisms to transform solid compounds ..... of metals from spent lithium ion secondary batteries using A.

  6. Engineering Design of Electrostatic Quadrupole for ISOL Beam Lines

    International Nuclear Information System (INIS)

    Kim, H. S.; Kwon, H. J.; Cho, Y. S.

    2014-01-01

    In the ISOL system, the RI beam should be transported from the target ion source to post accelerator through various analyzing and charge-breeding systems such as PS (pre-seperator), HRMS (High Resolution Mass Seperator), RF cooler and A/q separator. A reference particle for the beam dynamics calculation is 132 Sn 1+ . After charge breeder system, the charge state is boosted from +1 to +19 with ECR charge breeder and to +33 with EBIS charge breeder. Because the beam energy is as low as 50 keV, the electrostatic optics was adopted rather than the magnetic optics. The electrostatic quadrupole triplets were used for the beam focusing and the electrostatic bender is used for 90-degree bending. In this paper, the design procedure and engineering design of the electrostatic quadrupole are presented

  7. Electrostatic atomization emdash Experiment, theory and industrial applications

    International Nuclear Information System (INIS)

    Okuda, H.; Kelly, A.J.

    1996-01-01

    Experimental and theoretical research has been initiated at the Princeton Plasma Physics Laboratory on the electrostatic atomization process in collaboration with Charged Injection Corporation. The goal of this collaboration is to set up a comprehensive research and development program on the electrostatic atomization at the Princeton Plasma Physics Laboratory so that both institutions can benefit from the collaboration. Experimental, theoretical and numerical simulation approaches are used for this purpose. An experiment consisting of a capillary sprayer combined with a quadrupole mass filter and a charge detector was installed at the Electrostatic Atomization Laboratory to study fundamental properties of the charged droplets such as the distribution of charges with respect to the droplet radius. In addition, a numerical simulation model is used to study interaction of beam electrons with atmospheric pressure water vapor, supporting an effort to develop an electrostatic water mist fire-fighting nozzle. copyright 1996 American Institute of Physics

  8. Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

    Energy Technology Data Exchange (ETDEWEB)

    Ya' akobovitz, A. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering, Faculty of Engineering Sciences, Ben-Gurion University, Beer-Sheva (Israel); Bedewy, M. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Hart, A. J. [Mechanosynthesis Group, Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Department of Mechanical Engineering and Laboratory for Manufacturing and Productivity, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-02-02

    Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.

  9. The Contribution of Surface Potential to Diverse Problems in Electrostatics

    International Nuclear Information System (INIS)

    Horenstein, M

    2015-01-01

    Electrostatics spans many different subject areas. Some comprise “good electrostatics,” where charge is used for desirable purposes. Such areas include industrial manufacturing, electrophotography, surface modification, precipitators, aerosol control, and MEMS. Other areas comprise “bad electrostatics,” where charge is undesirable. Such areas include hazardous discharges, ESD, health effects, nuisance triboelectrification, particle contamination, and lightning. Conference proceedings such as this one inevitably include papers grouped around these topics. One common thread throughout is the surface potential developed when charge resides on an insulator surface. Often, the charged insulator will be in intimate contact with a ground plane. At other times, the charged insulator will be isolated. In either case, the resulting surface potential is important to such processes as propagating brush discharges, charge along a moving web, electrostatic biasing effects in MEMS, non-contacting voltmeters, field-effect transistor sensors, and the maximum possible charge on a woven fabric. (paper)

  10. Analytical solutions of the electrostatically actuated curled beam problem

    KAUST Repository

    Younis, Mohammad I.

    2014-01-01

    This works presents analytical expressions of the electrostatically actuated initially deformed cantilever beam problem. The formulation is based on the continuous Euler-Bernoulli beam model combined with a single-mode Galerkin approximation. We

  11. Factors affecting the electrostatic charge of ceramic powders

    International Nuclear Information System (INIS)

    Lorite, I.; Romero, J.; Fernandez, J. F.

    2011-01-01

    The phenomenon of electrostatic charge in ceramic powders takes place when the particle surfaces enter in contact between them or with the containers. The accumulation of electrostatic charge is of relevance in ceramic powders in view of their insulating character and the risk of explosions during the material handling. In this work the main factors that affect the appearance of intrinsic charge and tribo-charge in ceramic powder have been studied. In ceramic powders of alumina it has been verified that the smallest particle sizes present an increase of the electrostatic charge of negative polarity. A correlation has been observed between the nature of the OH -surface groups and the electrostatic charge. The intrinsic charge and the tribocharge in ceramic powders can be diminished by compensating the surface groups that support the charge. The dry dispersion of nanoparticles on microparticles allows surface charge compensation with a noticeable modification of the powder agglomeration. (Author) 19 refs.

  12. Structures, profile consistency, and transport scaling in electrostatic convection

    DEFF Research Database (Denmark)

    Bian, N.H.; Garcia, O.E.

    2005-01-01

    Two mechanisms at the origin of profile consistency in models of electrostatic turbulence in magnetized plasmas are considered. One involves turbulent diffusion in collisionless plasmas and the subsequent turbulent equipartition of Lagrangian invariants. By the very nature of its definition...

  13. Anionic lipids and the maintenance of membrane electrostatics in eukaryotes.

    Science.gov (United States)

    Platre, Matthieu Pierre; Jaillais, Yvon

    2017-02-01

    A wide range of signaling processes occurs at the cell surface through the reversible association of proteins from the cytosol to the plasma membrane. Some low abundant lipids are enriched at the membrane of specific compartments and thereby contribute to the identity of cell organelles by acting as biochemical landmarks. Lipids also influence membrane biophysical properties, which emerge as an important feature in specifying cellular territories. Such parameters are crucial for signal transduction and include lipid packing, membrane curvature and electrostatics. In particular, membrane electrostatics specifies the identity of the plasma membrane inner leaflet. Membrane surface charges are carried by anionic phospholipids, however the exact nature of the lipid(s) that powers the plasma membrane electrostatic field varies among eukaryotes and has been hotly debated during the last decade. Herein, we discuss the role of anionic lipids in setting up plasma membrane electrostatics and we compare similarities and differences that were found in different eukaryotic cells.

  14. An experimental study on anti-electrostatic gauge rulers

    International Nuclear Information System (INIS)

    Lou, Renjie; Dai, Liping; Sun, Hong

    2013-01-01

    The process of oil filling will produce electrostatic phenomena which may cause fire accidents. There were no reports about research on the danger of static electricity generation in the process of gauging operation to date. This paper presents an experiment on charge transferring quantity of gauge rulers, and calculates the charge transferring quantity of an anti-electrostatic gauge ruler and a metal one, respectively. The results indicate that the charge transferring quantity can be more than 0.1 μC for a metal gauge ruler, while it is less than 0.1 μC for an antistatic gauge ruler. Therefore, this experimental research proves that using an anti-electrostatic gauge ruler is safer than using a metal one. This study also provides some theoretical and experimental evidence for making anti-electrostatic gauge rulers.

  15. Static Response of Microbeams due to Capillary and Electrostatic Forces

    KAUST Repository

    Bataineh, Ahmad M.; Ouakad, Hassen M.; Younis, Mohammad I.

    2016-01-01

    Micro-sensors or micro-switches usually operate under the effect of electrostatic force and could face some environmental effects like humidity, which may lead to condensation underneath the beams and create strong capillary forces. Those tiny

  16. An Experimental and Theoretical Investigation of Electrostatically Coupled Cantilever Microbeams

    KAUST Repository

    Ilyas, Saad; Chappanda, Karumbaiah N.; Hafiz, Md Abdullah Al; Ramini, Abdallah; Younis, Mohammad I.

    2016-01-01

    We present an experimental and theoretical investigation of the static and dynamic behavior of electrostatically coupled laterally actuated silicon microbeams. The coupled beam resonators are composed of two almost identical flexible cantilever

  17. Analyzed method for calculating the distribution of electrostatic field

    International Nuclear Information System (INIS)

    Lai, W.

    1981-01-01

    An analyzed method for calculating the distribution of electrostatic field under any given axial gradient in tandem accelerators is described. This method possesses satisfactory accuracy compared with the results of numerical calculation

  18. Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

    International Nuclear Information System (INIS)

    Ya'akobovitz, A.; Bedewy, M.; Hart, A. J.

    2015-01-01

    Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices

  19. Electrostatic capacitance and Faraday cage behavior of carbon nanotube forests

    Science.gov (United States)

    Ya'akobovitz, A.; Bedewy, M.; Hart, A. J.

    2015-02-01

    Understanding of the electrostatic properties of carbon nanotube (CNT) forests is essential to enable their integration in microelectronic and micromechanical devices. In this study, we sought to understand how the hierarchical geometry and morphology of CNT forests determines their capacitance. First, we find that at small gaps, solid micropillars have greater capacitance, yet at larger gaps the capacitance of the CNT forests is greater. The surface area of the CNT forest accessible to the electrostatic field was extracted by analysis of the measured capacitance, and, by relating the capacitance to the average density of CNTs in the forest, we find that the penetration depth of the electrostatic field is on the order of several microns. Therefore, CNT forests can behave as a miniature Faraday cage. The unique electrostatic properties of CNT forests could therefore enable their use as long-range proximity sensors and as shielding elements for miniature electronic devices.

  20. Molecular electrostatic potential analysis of non-covalent complexes

    Indian Academy of Sciences (India)

    Chemical Sciences and Technology Division and Academy of Scientific & Innovative Research (AcSIR), ... workers proposed the electrostatic-covalent model of hydrogen bonding. ..... tain degree of electron donation and acceptance occurs.

  1. Aerial electrostatic spray deposition and canopy penetration in cotton

    Science.gov (United States)

    Spray deposition on abaxial and adaxial leaf surfaces along with canopy penetration are essential for insect control and foliage defoliation in cotton production agriculture. Researchers have reported that electrostatically charged sprays have increased spray deposit onto these surfaces under widel...

  2. Test plan for engineering scale electrostatic enclosure demonstration

    International Nuclear Information System (INIS)

    Meyer, L.C.

    1993-02-01

    This test plan describes experimental details of an engineering-scale electrostatic enclosure demonstration to be performed at the Idaho National Engineering Laboratory in fiscal year (FY)-93. This demonstration will investigate, in the engineering scale, the feasibility of using electrostatic enclosures and devices to control the spread of contaminants during transuranic waste handling operations. Test objectives, detailed experimental procedures, and data quality objectives necessary to perform the FY-93 experiments are included in this plan

  3. Electrostatic storage rings for atomic and molecular physics

    International Nuclear Information System (INIS)

    Schmidt, H T

    2015-01-01

    A significant number of electrostatic ion-storage rings have been built since the late 1990s or are currently in their construction or commisioning phases. In this short contribution, we attempt to supply an overview of these different facilities, while we also mention a selection of the electrostatic ion-beam traps that has been developed through the same time period and by some of the same research groups. (paper)

  4. Electrostatic quadrupole array for focusing parallel beams of charged particles

    International Nuclear Information System (INIS)

    Brodowski, J.

    1982-01-01

    An array of electrostatic quadrupoles, capable of providing strong electrostatic focusing simultaneously on multiple beams, is easily fabricated from a single array element comprising a support rod and multiple electrodes spaced at intervals along the rod. The rods are secured to four terminals which are isolated by only four insulators. This structure requires bias voltage to be supplied to only two terminals and eliminates the need for individual electrode bias and insulators, as well as increases life by eliminating beam plating of insulators

  5. Ion-Beam-Excited Electrostatic Ion Cyclotron Waves

    DEFF Research Database (Denmark)

    Michelsen, Poul; Pécseli, Hans; Juul Rasmussen, Jens

    1976-01-01

    Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field.......Self-excited electrostatic ion cyclotron waves were observed in an ion-beam-plasma system produced in a DP-operated Q-machine. The frequency of the waves showed the theoretically predicted variation with the magnetic field....

  6. A fast electrostatic chopper of low power consumption

    International Nuclear Information System (INIS)

    Bizzeti, P.G.; Fazzini, T.; Taccetti, N.

    1979-01-01

    An electrostatic chopper for the continuous beams of a 7.5 MV Van de Graaff accelerator is described. The electrostatic deflector uses complemetary transistors, driven by optoelectronic couplers, as voltage switches. The power consumption of the high voltage system at 30 kHz repetition frequency is approximately 3 W. Rise and fall times are symmetric and of the order of 0.4 μs. Experimental time spectra of prompt and delayed γ-rays are presented. (Auth.)

  7. An electrostatic storage ring for low kinetic energy electron collisions

    Energy Technology Data Exchange (ETDEWEB)

    Reddish, T J; Tessier, D R; Sullivan, M R; Thorn, P A [Department of Physics, University of Windsor, Windsor, N9B 3P4 (Canada); Hammond, P; Alderman, A J [School of Physics, CAMSP, University of Western Australia, Perth WA 6009 (Australia); Read, F H [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

    2009-11-01

    The criteria are presented for stable multiple orbits of charged particles in a race-track shaped storage ring and applied to an electrostatic system consisting of two hemispherical deflector analyzers (HDA) connected by two separate sets of cylindrical lenses. The results of charged particle simulations and the formal matrix theory, including aberrations in the energy-dispersive electrostatic 'prisms', are in good agreement with the observed experimental operating conditions for this Electron Recycling Spectrometer (ERS).

  8. Linear and Nonlinear Electrostatic Waves in Unmagnetized Dusty Plasmas

    International Nuclear Information System (INIS)

    Mamun, A. A.; Shukla, P. K.

    2010-01-01

    A rigorous and systematic theoretical study has been made of linear and nonlinear electrostatic waves propagating in unmagnetized dusty plasmas. The basic features of linear and nonlinear electrostatic waves (particularly, dust-ion-acoustic and dust-acoustic waves) for different space and laboratory dusty plasma conditions are described. The experimental observations of such linear and nonlinear features of dust-ion-acoustic and dust-acoustic waves are briefly discussed.

  9. Revised electrostatic model of the LISA Pathfinder inertial sensor

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Nico [Astrium GmbH, 88039 Friedrichshafen (Germany); Fichter, Walter, E-mail: nico.brandt@astrium.eads.ne [iFR, Universitaet Stuttgart, Pfaffenwaldring 7a, 70569 Stuttgart (Germany)

    2009-03-01

    A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

  10. Revised electrostatic model of the LISA Pathfinder inertial sensor

    International Nuclear Information System (INIS)

    Brandt, Nico; Fichter, Walter

    2009-01-01

    A comprehensive electrostatic finite-element (FE) analysis of the LISA Pathfinder Inertial Sensor (IS) has been carried out at Astrium GmbH. Starting with a detailed geometrical model of the IS housing and test mass (TM) flight units, FE results were derived from multiple analyses runs applying the Maxwell 3D field simulation software. The electrostatic forces and torques on the TM in 6DoF, as well as all non-negligible capacitances between the TM, the 18 electrodes, and the housing, have been extracted for different TM translations and rotations. The results of the FE analyses were expected to confirm the existing IS electrostatic model predictions used for performance analysis, simulations, and on-board algorithms. Major discrepancies were found, however, between the results and the model used so far. In general, FE results give considerably larger capacitance values than the equivalent infinite non-parallel plate estimates. In contrast, the FE derived forces and torques are in general significantly lower compared to the analytic IS electrostatic model predictions. In this paper, these results are discussed in detail and the reasons for the deviations are elaborated. Based on these results, an adapted analytic IS electrostatic model is proposed that reflects the electrostatic forces, torques, and stiffness values in the LISA Pathfinder IS significantly more accurate.

  11. A Solvatochromic Model Calibrates Nitriles’ Vibrational Frequencies to Electrostatic Fields

    Science.gov (United States)

    Bagchi, Sayan; Fried, Stephen D.; Boxer, Steven G.

    2012-01-01

    Electrostatic interactions provide a primary connection between a protein’s three-dimensional structure and its function. Infrared (IR) probes are useful because vibrational frequencies of certain chemical groups, such as nitriles, are linearly sensitive to local electrostatic field, and can serve as a molecular electric field meter. IR spectroscopy has been used to study electrostatic changes or fluctuations in proteins, but measured peak frequencies have not been previously mapped to total electric fields, because of the absence of a field-frequency calibration and the complication of local chemical effects such as H-bonds. We report a solvatochromic model that provides a means to assess the H-bonding status of aromatic nitrile vibrational probes, and calibrates their vibrational frequencies to electrostatic field. The analysis involves correlations between the nitrile’s IR frequency and its 13C chemical shift, whose observation is facilitated by a robust method for introducing isotopes into aromatic nitriles. The method is tested on the model protein Ribonuclease S (RNase S) containing a labeled p-CN-Phe near the active site. Comparison of the measurements in RNase S against solvatochromic data gives an estimate of the average total electrostatic field at this location. The value determined agrees quantitatively with MD simulations, suggesting broader potential for the use of IR probes in the study of protein electrostatics. PMID:22694663

  12. An efficient numerical approach to electrostatic microelectromechanical system simulation

    International Nuclear Information System (INIS)

    Pu, Li

    2009-01-01

    Computational analysis of electrostatic microelectromechanical systems (MEMS) requires an electrostatic analysis to compute the electrostatic forces acting on micromechanical structures and a mechanical analysis to compute the deformation of micromechanical structures. Typically, the mechanical analysis is performed on an undeformed geometry. However, the electrostatic analysis is performed on the deformed position of microstructures. In this paper, a new efficient approach to self-consistent analysis of electrostatic MEMS in the small deformation case is presented. In this approach, when the microstructures undergo small deformations, the surface charge densities on the deformed geometry can be computed without updating the geometry of the microstructures. This algorithm is based on the linear mode shapes of a microstructure as basis functions. A boundary integral equation for the electrostatic problem is expanded into a Taylor series around the undeformed configuration, and a new coupled-field equation is presented. This approach is validated by comparing its results with the results available in the literature and ANSYS solutions, and shows attractive features comparable to ANSYS. (general)

  13. Electrostatic Transport and Manipulation of Lunar Soil and Dust

    International Nuclear Information System (INIS)

    Kawamoto, Hiroyuki

    2008-01-01

    Transport and manipulation technologies of lunar soil and dust are under development utilizing the electrostatic force. Transport of particles is realized by an electrostatic conveyer consisting of parallel electrodes. Four-phase traveling electrostatic wave was applied to the electrodes to transport particles upon the conveyer and it was demonstrated that particles were efficiently transported under conditions of low frequency, high voltage, and the application of rectangular wave. Not only linear but also curved and closed transport was demonstrated. Numerical investigation was carried out with a three-dimensional hard-sphere model of the Distinct Element Method to clarify the mechanism of the transport and to predict performances in the lunar environment. This technology is expected to be utilized not only for the transport of bulk soil but also for the cleaning of a solar panel and an optical lens. Another technology is an electrostatic manipulation system to manipulate single particle. A manipulator consisted of two parallel pin electrodes. When voltage was applied between the electrodes, electrophoresis force generated in non-uniform electrostatic field was applied to the particle near the tip of the electrode. The particle was captured by the application of the voltage and released from the manipulator by turning off the voltage. It was possible to manipulate not only insulative but also conductive particles. Three-dimensional electrostatic field calculation was conducted to calculate the electrophoresis force and the Coulomb force

  14. Manufacture of electrostatic septum for extracting particle beam

    International Nuclear Information System (INIS)

    Tokumoto, Shuichi

    1979-01-01

    In the main ring of National Laboratory for High Energy Physics, fast and slow extractions of accelerated proton beam are carried out by using electrostatic septa. The electrostatic septum is an apparatus to deflect beam by an electrostatic field, basically composed of a couple of parallel plate electrodes installed in a vacuum chamber. The electrostatic septum is required to satisfy the following two conditions: it must be very thin and flat to reduce the loss of extracted beam, and sufficiently high electric field must be generated to deflect beam in a limited length. The structure and manufacture of electrostatic septa are described. The manufacturing is explained by dividing a septum into an anode and a cathode, terminals introducing high voltage, a vacuum chamber, and high voltage circuit. The performance is also described on the experiments for no-beam condition and beam extraction. Beam extraction has been carried out over 1500 hours thus far, the average beam intensity being 1 x 10 12 ppp, and extraction efficiency more than 90%. There have been no serious failure to affect the performance nor metal wire breakage. They have satisfied their purposes, being used for both fast and slow extractions. Presently, lengthening of the electrostatic field region is being planned to increase the length of the septa to 1.5 m per unit. (Wakatsuki, Y.)

  15. Design space of electrostatic chuck in etching chamber

    International Nuclear Information System (INIS)

    Sun Yuchun; Cheng Jia; Lu Yijia; Hou Yuemin; Ji Linhong

    2015-01-01

    One of the core semiconductor devices is the electrostatic chuck. It has been widely used in plasma-based and vacuum-based semiconductor processing. The electrostatic chuck plays an important role in adsorbing and cooling/heating wafers, and has technical advantages on non-edge exclusion, high reliability, wafer planarity, particles reduction and so on. This article extracts key design elements from the existing knowledge and techniques of electrostatic chuck by the method proposed by Paul and Beitz, and establishes a design space systematically. The design space is composed of working objects, working principles and working structures. The working objects involve electrostatic chuck components and materials, classifications, and relevant properties; the working principles involve clamping force, residual force, and temperature control; the working structures describe how to compose an electrostatic chuck and to fulfill the overall functions. The systematic design space exhibits the main issues during electrostatic chuck design. The design space will facilitate and inspire designers to improve the design quality and shorten the design time in the conceptual design. (paper)

  16. Nonlinear Dynamics of Carbon Nanotubes Under Large Electrostatic Force

    KAUST Repository

    Xu, Tiantian

    2015-06-01

    Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction of their cylindrical shape, forming upper electrodes, to lower electrodes poises serious computational challenges. This presents an obstacle against applying and using several nonlinear dynamics tools typically used to analyze the behavior of complicated nonlinear systems undergoing large motion, such as shooting, continuation, and integrity analysis techniques. This works presents an attempt to resolve this issue. We present an investigation of the nonlinear dynamics of carbon nanotubes when actuated by large electrostatic forces. We study expanding the complicated form of the electrostatic force into enough number of terms of the Taylor series. Then, we utilize this form along with an Euler-Bernoulli beam model to study for the first time the dynamic behavior of CNTs when excited by large electrostatic force. The geometric nonlinearity and the nonlinear electrostatic force are considered. An efficient reduced-order model (ROM) based on the Galerkin method is developed and utilized to simulate the static and dynamic responses of the CNTs. Several results are generated demonstrating softening and hardening behavior of the CNTs near their primary and secondary resonances. The effects of the DC and AC voltage loads on the behavior have been studied. The impacts of the initial slack level and CNT diameter are also demonstrated.

  17. NONLINEAR DYNAMICS OF CARBON NANOTUBES UNDER LARGE ELECTROSTATIC FORCE

    KAUST Repository

    Xu, Tiantian

    2015-06-01

    Because of the inherent nonlinearities involving the behavior of CNTs when excited by electrostatic forces, modeling and simulating their behavior is challenging. The complicated form of the electrostatic force describing the interaction of their cylindrical shape, forming upper electrodes, to lower electrodes poises serious computational challenges. This presents an obstacle against applying and using several nonlinear dynamics tools typically used to analyze the behavior of complicated nonlinear systems undergoing large motion, such as shooting, continuation, and integrity analysis techniques. This works presents an attempt to resolve this issue. We present an investigation of the nonlinear dynamics of carbon nanotubes when actuated by large electrostatic forces. We study expanding the complicated form of the electrostatic force into enough number of terms of the Taylor series. Then, we utilize this form along with an Euler-Bernoulli beam model to study for the first time the dynamic behavior of CNTs when excited by large electrostatic force. The geometric nonlinearity and the nonlinear electrostatic force are considered. An efficient reduced-order model (ROM) based on the Galerkin method is developed and utilized to simulate the static and dynamic responses of the CNTs. Several results are generated demonstrating softening and hardening behavior of the CNTs near their primary and secondary resonances. The effects of the DC and AC voltage loads on the behavior have been studied. The impacts of the initial slack level and CNT diameter are also demonstrated.

  18. Electrostatic Dust Detection and Removal for ITER

    International Nuclear Information System (INIS)

    C.H. Skinner; A. Campos; H. Kugel; J. Leisure; A.L. Roquemore; S. Wagner

    2008-01-01

    We present some recent results on two innovative applications of microelectronics technology to dust inventory measurement and dust removal in ITER. A novel device to detect the settling of dust particles on a remote surface has been developed in the laboratory. A circuit board with a grid of two interlocking conductive traces with 25 (micro)m spacing is biased to 30-50 V. Carbon particles landing on the energized grid create a transient short circuit. The current flowing through the short circuit creates a voltage pulse that is recorded by standard nuclear counting electronics and the total number of counts is related to the mass of dust impinging on the grid. The particles typically vaporize in a few seconds restoring the previous voltage standoff. Experience on NSTX however, showed that in a tokamak environment it was still possible for large particles or fibers to remain on the grid causing a long term short circuit. We report on the development of a gas puff system that uses helium to clear such particles. Experiments with varying nozzle designs, backing pressures, puff durations, and exit flow orientations have given an optimal configuration that effectively removes particles from an area up to 25 cm 2 with a single nozzle. In a separate experiment we are developing an advanced circuit grid of three interlocking traces that can generate a miniature electrostatic traveling wave for transporting dust to a suitable exit port. We have fabricated such a 3-pole circuit board with 25 micron insulated traces that operates with voltages up to 200 V. Recent results showed motion of dust particles with the application of only 50 V bias voltage. Such a device could potentially remove dust continuously without dedicated interventions and without loss of machine availability for plasma operations

  19. Studies of spherical inertial-electrostatic confinement

    International Nuclear Information System (INIS)

    Miley, G.H.

    1992-01-01

    Theoretical and experimental results from studies of Spherical Inertial-Electrostatic Confinement (SIEC) are presented. This principle of IEC involves the confinement by multiple potential wells created by ion injection into a spherical device containing biased grids. A semitransparent cathode accelerates ions, generating a spherical ion-beam flow which converges at the center of the spherical volume, creating a space charge (potential well) region. An electron flow is created by the core (virtual anode) region, forming in turn a virtual cathode. Ions trapped inside this well oscillate back and forth until they fuse or degrade in energy. Such multiple wells with virtual anodes and cathodes, have been called ''Poissors'' following the original work by Farnsworth and by Hirsch. Fusion within the core occurs by reactions between non-Maxwellian beam-beam type ions. This has the potential for achieving a high power density and also for burning both D-T and advanced fuels. If successful, such a device would be attractive for a variety of high power density applications, e.g., space power or as a neutron source based on D-D or D-T operation. Simulations of recent SIEC experiments have been carried out using the XL-code, to solve Poisson's equation, self-consistently with the collisionless Vlasov equation in spherical geometry for several current species and grid parameters. The potential profile predictions are reasonably consistent with experimental results. Potential well measurements used a collimated proton detector. Results indicate that an ∼ 15-kV virtual anode, at least one centimeter in radius, was formed in a spherical device with a cathode potential of 30 kV using an ion current of ∼ 30 mA. Analysis indicates D + densities on the order of 10 9 cm -3 , and D 2 + densities on the order of 10 10 cm -3 . Steady-state D-D neutron emission of about 10 6 n/sec is observed

  20. Fabrication of miniaturized electrostatic deflectors using LIGA

    International Nuclear Information System (INIS)

    Jackson, K.H.; Khan-Malek, C.; Muray, L.P.

    1997-01-01

    Miniaturized electron beam columns (open-quotes microcolumnsclose quotes) have been demonstrated to be suitable candidates for scanning electron microscopy (SEM), e-beam lithography and other high resolution, low voltage applications. In the present technology, microcolumns consist of open-quotes selectively scaledclose quotes micro-sized lenses and apertures, fabricated from silicon membranes with e-beam lithography, reactive ion beam etching and other semiconductor thin-film techniques. These miniaturized electron-optical elements provide significant advantages over conventional optics in performance and ease of fabrication. Since lens aberrations scale roughly with size, it is possible to fabricate simple microcolumns with extremely high brightness sources and electrostatic objective lenses, with resolution and beam current comparable to conventional e-beam columns. Moreover since microcolumns typically operate at low voltages (1 KeV), the proximity effects encountered in e-beam lithography become negligible. For high throughput applications, batch fabrication methods may be used to build large parallel arrays of microcolumns. To date, the best reported performance with a 1 keV cold field emission cathode, is 30 nm resolution at a working distance of 2mm in a 3.5mm column. Fabrication of the microcolumn deflector and stigmator, however, have remained beyond the capabilities of conventional machining operations and semiconductor processing technology. This work examines the LIGA process as a superior alternative to fabrication of the deflectors, especially in terms of degree of miniaturization, dimensional control, placement accuracy, run-out, facet smoothness and choice of suitable materials. LIGA is a combination of deep X-ray lithography, electroplating, and injection molding processes which allow the fabrication of microstructures

  1. Electrostatic charge characteristics of jet nebulized aerosols.

    Science.gov (United States)

    Kwok, Philip Chi Lip; Trietsch, Sebastiaan J; Kumon, Michiko; Chan, Hak-Kim

    2010-06-01

    Liquid droplets can be spontaneously charged in the absence of applied electric fields by spraying. It has been shown by computational simulation that charges may influence particle deposition in the airways. The electrostatic properties of jet nebulized aerosols and their potential effects on lung deposition have hardly been studied. A modified electrical low pressure impactor (ELPI) was employed to characterize the aerosol charges generated from jet nebulized commercial products. The charge and size measurements were conducted at 50% RH and 22 degrees C with a modified ELPI. Ventolin, Bricanyl, and Atrovent were nebulized using PARI LC Plus jet nebulizers coupled to a DeVilbiss Pulmo-Aide compressor. The aerosols were sampled in 30-sec durations. The drug deposits on the impactor stages were assayed chemically using high-performance liquid chromatography (HPLC). The charges of nebulized deionized water, isotonic saline, and the three commercial products diluted with saline were also measured to analyze the contributions of the major nebule ingredients on charging. No mass assays were performed on these runs. All three commercial nebules generated net negative charges. The magnitude of the charges reduced over the period of nebulization. Ventolin and Bricanyl yielded similar charge profiles. Highly variable charges were produced from deionized water. On the other hand, nebulized saline reproducibly generated net positive charges. Diluted commercial nebules showed charge polarity inversion. The charge profiles of diluted salbutamol and terbutaline solutions resembled those of saline, while the charges from diluted ipratropium solutions fluctuated near neutrality. The charge profiles were shown to be influenced by the concentration and physicochemical properties of the drugs, as well as the history of nebulization. The drugs may have unique isoelectric concentrations in saline at which the nebulized droplets would carry near-zero charges. According to results from

  2. Energy of linear quasineutral electrostatic drift waves

    International Nuclear Information System (INIS)

    Pfirsch, D.; Correa-Restrepo, D.

    1993-01-01

    Certain kinds of nonlinear instabilities are related to the existence of negative-energy perturbations. In this paper, an exact energy expression for linear quasineutral electrostatic perturbations is derived within the framework of dissipationless multifluid theory that is valid for any geometry. Taking the mass formally as a tensor with, in general, different masses parallel and perpendicular to an ambient magnetic field allows one to treat in a convenient way different approximations such as the full dynamics and restriction to parallel dynamics or the completely adiabatic case. Application to slab configurations yields the result that the adiabatic approximation does not allow negative energy for perturbations which are perfectly localized at a mode resonant surface, whereas inclusion of the parallel dynamics does. This is in agreement with a recent numerical study of drift-wave turbulence within the framework of collisional two-fluid theory by B. Scott [Phys. Rev. Lett. 65, 3289 (1990); Phys. Fluids B 4, 2468 (1992)]. A dissipationless theory can be formulated in terms of a Lagrangian, from which the energy is immediately obtained. We start with the nonlinear theory. The theory is formulated via a Lagrangian which is written in terms of displacement vectors ξ ν (x,t) such that all constraints are taken into account. The nonlinear energy is obtained from the Lagrangian by standard methods. The procedure used is the same as that developed in a forthcoming paper by Pfirsch and Sudan [Phys. Fluids B (to be published)] for ideal nonlinear magnetohydrodynamics theory. From the exact Lagrangian one obtains the Lagrangian of the linearized theory by simple expansion to second order in ξ ν . This Lagrangian then yields the energy of the linearized theory

  3. The establishment and application of direct coupled electrostatic-structural field model in electrostatically controlled deployable membrane antenna

    Science.gov (United States)

    Gu, Yongzhen; Duan, Baoyan; Du, Jingli

    2018-05-01

    The electrostatically controlled deployable membrane antenna (ECDMA) is a promising space structure due to its low weight, large aperture and high precision characteristics. However, it is an extreme challenge to describe the coupled field between electrostatic and membrane structure accurately. A direct coupled method is applied to solve the coupled problem in this paper. Firstly, the membrane structure and electrostatic field are uniformly described by energy, considering the coupled problem is an energy conservation phenomenon. Then the direct coupled electrostatic-structural field governing equilibrium equations are obtained by energy variation approach. Numerical results show that the direct coupled method improves the computing efficiency by 36% compared with the traditional indirect coupled method with the same level accuracy. Finally, the prototype has been manufactured and tested and the ECDMA finite element simulations show good agreement with the experiment results as the maximum surface error difference is 6%.

  4. Influence of post-bleaching time intervals on dentin bond strength Influência de tempos de espera pós-clareamento na resistência adesiva da dentina

    Directory of Open Access Journals (Sweden)

    Erica Cappelletto Nogueira Teixeira

    2004-03-01

    Full Text Available It has been reported that bond strength of resin to tooth structure can be reduced when the bonding procedure is carried out immediately after the bleaching treatment. This study evaluated the effect of bleaching of non-vital teeth bleaching on the shear bond strength (SBS of composite resin/bovine dentin interface and the influence of delaying the bonding procedures for different time intervals following internal bleaching. According to a randomized block design, composite resin cylinders (Z100/Single bond - 3M were bonded to the flattened dentin surface of two hundred and fifty-six teeth which had previously been subjected to four different treatments: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP - 37% carbamide peroxide; and CON - distilled water (control, each one followed by storage in artificial saliva for 0 (baseline, 7, 14, and 21 days after bleaching (n = 16. The bleaching agents in the pulp chambers were replaced every 7 days, over 4 weeks. The SBS test of the blocks was done using a universal testing machine. The ANOVA showed that there was no significant interaction between time and bleaching agents, and that the factor time was not statistically significant (p > 0.05. For the factor bleaching treatment, the Student's t-test showed that [CON = CP] > [SPW = SPH]. The bleaching of non-vital teeth affected the resin/dentin SBS values when sodium perborate mixed with 30% hydrogen peroxide or water was used, independently of the elapsed time following the bleaching treatment.Tem-se sugerido que a qualidade da adesão resina composta-dentina pode ser prejudicada quando restaurações são confeccionadas imediatamente após o tratamento clareador. Este estudo avaliou o efeito da postergação do procedimento adesivo após o clareamento interno realizado com diferentes agentes na resistência ao cisalhamento da interface compósito/dentina. De acordo com um delineamento aleatório em blocos

  5. PREFACE: 7th International Conference on Applied Electrostatics (ICAES-2012)

    Science.gov (United States)

    Li, Jie

    2013-03-01

    ICAES is an important conference organized every four years by the Committee on Electrostatics of the Chinese Physical Society, which serves as a forum for scientists, educators and engineers interested in the fundamentals, applications, disasters and safety of electrostatics, etc. In recent years, new techniques, applications and fundamental theories on electrostatics have developed considerably. ICAES-7, held in Dalian, China, from 17-19 September 2012, aimed to provide a forum for all scholars to report the newest developments in electrostatics, to probe the questions that scholars faced and to discuss fresh ideas related to electrostatics. ICAES-7 was co-organized and hosted by Dalian University of Technology, and was sponsored by the Ministry of Education of China, the National Natural Science Foundation of China, Dalian University of Technology, Nanjing Suman Electronics Co. Ltd (Suman, China), Shekonic (Yangzhou Shuanghong, China) Electric/Mechanical Co. Ltd, and Suzhou TA&A Ultra Clean Technology Co. Ltd. (China). On behalf of the organizing committee of ICAES-7, I express my great appreciation for their support of the conference. Over 160 scholars and engineers from many countries including Croatia, The Czech Republic, D.P.R. Korea, Germany, Japan, Malaysia, Poland, Russia, the United States of America, China attended ICAES-7, and the conference collected and selected 149 papers for publication. The subjects of those papers cover the fundamentals of electrostatics, electrostatic disaster and safety, and electrostatic application (e.g. precipitation, pollutant control, biological treatment, mixture separation and food processing, etc). I cordially thank all authors and attendees for their support, and my appreciation is also given to the conference honorary chair, the organizing committee and advisory committee, and the conference secretaries for their hard work. ICAES-7 is dedicated to the memory of Professor Jen-Shih Chang (professor emeritus in the

  6. Understanding and Manipulating Electrostatic Fields at the Protein-Protein Interface Using Vibrational Spectroscopy and Continuum Electrostatics Calculations.

    Science.gov (United States)

    Ritchie, Andrew W; Webb, Lauren J

    2015-11-05

    Biological function emerges in large part from the interactions of biomacromolecules in the complex and dynamic environment of the living cell. For this reason, macromolecular interactions in biological systems are now a major focus of interest throughout the biochemical and biophysical communities. The affinity and specificity of macromolecular interactions are the result of both structural and electrostatic factors. Significant advances have been made in characterizing structural features of stable protein-protein interfaces through the techniques of modern structural biology, but much less is understood about how electrostatic factors promote and stabilize specific functional macromolecular interactions over all possible choices presented to a given molecule in a crowded environment. In this Feature Article, we describe how vibrational Stark effect (VSE) spectroscopy is being applied to measure electrostatic fields at protein-protein interfaces, focusing on measurements of guanosine triphosphate (GTP)-binding proteins of the Ras superfamily binding with structurally related but functionally distinct downstream effector proteins. In VSE spectroscopy, spectral shifts of a probe oscillator's energy are related directly to that probe's local electrostatic environment. By performing this experiment repeatedly throughout a protein-protein interface, an experimental map of measured electrostatic fields generated at that interface is determined. These data can be used to rationalize selective binding of similarly structured proteins in both in vitro and in vivo environments. Furthermore, these data can be used to compare to computational predictions of electrostatic fields to explore the level of simulation detail that is necessary to accurately predict our experimental findings.

  7. Method for improving the electrostatics perforation pattern using power controlled discharges

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, C; Miranda, E; GarcIa-Garcia, J [Departament d' Enginyeria Electronica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain); Martinez-Cisneros, C; Alonso, J, E-mail: carolina.garzon@uab.cat [Departament de Quimica Analitica, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain)

    2011-06-23

    The aims of this work are to show the influence of adding a series resistance at the output of a discharge generator circuit and to point out that this component can be used to control the spark energy in electrostatic perforation systems. Analysis of the experimental results reveals that there exists a close connection between the resistor value and the obtained perforation pattern both in hole density and size. The use of a series resistor has a strong influence on the material porosity, which is an important industrial parameter for assessing the pattern perforation quality.

  8. Deposition of Ni-CGO composite anodes by electrostatic assisted ultrasonic spray pyrolysis method

    International Nuclear Information System (INIS)

    Chen, J.-C.; Chang, C.-L.; Hsu, C.-S.; Hwang, B.-H.

    2007-01-01

    Deposition of composite films of Ni and Gd-doped ceria was carried out using the electrostatic assisted ultrasonic spray pyrolysis method for the first time. The composite films were highly homogeneous, as revealed by element mapping via energy-dispersive spectrometry. Scanning electron microscope examinations revealed that deposition temperature and electric field strength had profound influence on resultant microstructure, while composition of the precursor solution had little effect. A highly porous cauliflower structure ideal for solid oxide fuel cell anode performance was obtained with a deposition temperature of 450 deg. C under an electric field introduced by an applied voltage of 12 kV. Films obtained with a lower deposition temperature of 250 deg. C or a higher applied voltage of 15 kV resulted in denser films with low porosity, while lower applied voltages of 7 or 5 kV resulted in thinner or discontinuous films due to the insufficient electrostatic attraction on the aerosol droplets. As revealed by AC impedance measurement, the area specific resistances of the Ni-CGO anode with porous cauliflower structure were rather low and a value of 0.09 Ω cm 2 at 550 deg. C was obtained

  9. Nanoconfined ionic liquids: Disentangling electrostatic and viscous forces

    Science.gov (United States)

    Lhermerout, Romain; Perkin, Susan

    2018-01-01

    Recent reports of surface forces across nanoconfined ionic liquids have revealed the existence of an anomalously long-ranged interaction apparently of electrostatic origin. Ionic liquids are viscous, and therefore it is important to inspect rigorously whether the observed repulsive forces are indeed equilibrium forces or, rather, arise from the viscous force during drainage of the fluid between two confining surfaces. In this paper we present our direct measurements of surface forces between mica sheets approaching in the ionic liquid [C2C1Im ] [NTf2] , exploring three orders of magnitude in approach velocity. Trajectories are systematically fitted by solving the equation of motion, allowing us to disentangle the viscous and equilibrium contributions. First, we find that the drainage obeys classical hydrodynamics with a negative slip boundary condition in the range of the structural force, implying that a nanometer -thick portion of the liquid in the vicinity of the solid surface is composed of ordered molecules that do not contribute to the flow. Second, we show that a long-range static force must indeed be invoked, in addition to the viscous force, in order to describe the data quantitatively. This equilibrium interaction decays exponentially and with decay length in agreement with the screening length reported for the same system in previous studies. In those studies the decay was simply checked to be independent of velocity and measured at a low approach rate, rather than explicitly taking account of viscous effects: we explain why this gives indistinguishable outcomes for the screening length by noting that the viscous force is linear to very good approximation over a wide range of distances.

  10. Electrostatic design and beam transport for a folded tandem electrostatic quadrupole accelerator facility for accelerator-based boron neutron capture therapy

    International Nuclear Information System (INIS)

    Thatar Vento, V.; Bergueiro, J.; Cartelli, D.; Valda, A.A.; Kreiner, A.J.

    2011-01-01

    Within the frame of an ongoing project to develop a folded Tandem-Electrostatic-Quadrupole (TESQ) accelerator facility for Accelerator-Based Boron Neutron Capture Therapy (AB-BNCT), we discuss here the electrostatic design of the machine, including the accelerator tubes with electrostatic quadrupoles and the simulations for the transport and acceleration of a high intensity beam.

  11. Evaluation of Electrostatic Force on Bipolar Charged Electret

    International Nuclear Information System (INIS)

    Sonoda, K; Minami, K; Miwatani, N; Fujita, T; Kanda, K; Maenaka, K

    2014-01-01

    This paper presents an evaluation of an electrostatic vibration energy harvester with the bipolar charged electret. The energy harvester with the size of 13 × 12 × 1.2 mm 3 was fabricated. The output power of the bipolar charged with ±250 V harvester was 9 μW when the acceleration was 1.4 g at 352 Hz with 0.9 MΩ load resistance. The effectiveness against the velocity-damped resonant-generator (VDRG) limit was 2.5%. The electrostatic forces of the actual device with DC bias, which simulates charged electret with monopolar and bipolar were experimentally and numerically verified. We estimated the electrostatic force by measuring the vibration amplitude versus applied acceleration of the electret mass. As a result, we investigated the bipolar charged device can reduce the effect of electrostatic force as low as no bias condition. The numerical model of the energy harvester considering the electrostatic force by FEM static analysis was also established. The comparison between the numerical model and the measurement results showed a similar inclination

  12. Electrostatic solitons in unmagnetized hot electron-positron-ion plasmas

    International Nuclear Information System (INIS)

    Mahmood, S.; Ur-Rehman, H.

    2009-01-01

    Linear and nonlinear electrostatic waves in unmagnetized electron-positron-ion (e-p-i) plasmas are studied. The electrons and positrons are assumed to be isothermal and dynamic while ions are considered to be stationary to neutralize the plasma background only. It is found that both upper (fast) and lower (slow) Langmuir waves can propagates in such a type of pair (e-p) plasma in the presence of ions. The small amplitude electrostatic Korteweg-de Vries (KdV) solitons are also obtained using reductive perturbation method. The electrostatic potential hump structures are found to exist when the temperature of the electrons is larger than the positrons, while the electrostatic potential dips are obtained in the reverse temperature conditions for electrons and positrons in e-p-i plasmas. The numerical results are also shown for illustration. The effects of different ion concentration and temperature ratios of electrons and positrons, on the formation of nonlinear electrostatic potential structures in e-p-i plasmas are also discussed.

  13. AESOP: A Python Library for Investigating Electrostatics in Protein Interactions.

    Science.gov (United States)

    Harrison, Reed E S; Mohan, Rohith R; Gorham, Ronald D; Kieslich, Chris A; Morikis, Dimitrios

    2017-05-09

    Electric fields often play a role in guiding the association of protein complexes. Such interactions can be further engineered to accelerate complex association, resulting in protein systems with increased productivity. This is especially true for enzymes where reaction rates are typically diffusion limited. To facilitate quantitative comparisons of electrostatics in protein families and to describe electrostatic contributions of individual amino acids, we previously developed a computational framework called AESOP. We now implement this computational tool in Python with increased usability and the capability of performing calculations in parallel. AESOP utilizes PDB2PQR and Adaptive Poisson-Boltzmann Solver to generate grid-based electrostatic potential files for protein structures provided by the end user. There are methods within AESOP for quantitatively comparing sets of grid-based electrostatic potentials in terms of similarity or generating ensembles of electrostatic potential files for a library of mutants to quantify the effects of perturbations in protein structure and protein-protein association. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  14. Electrostatic stiffening and induced persistence length for coassembled molecular bottlebrushes

    Science.gov (United States)

    Storm, Ingeborg M.; Stuart, Martien A. Cohen; de Vries, Renko; Leermakers, Frans A. M.

    2018-03-01

    A self-consistent field analysis for tunable contributions to the persistence length of isolated semiflexible polymer chains including electrostatically driven coassembled deoxyribonucleic acid (DNA) bottlebrushes is presented. When a chain is charged, i.e., for polyelectrolytes, there is, in addition to an intrinsic rigidity, an electrostatic stiffening effect, because the electric double layer resists bending. For molecular bottlebrushes, there is an induced contribution due to the grafts. We explore cases beyond the classical phantom main-chain approximation and elaborate molecularly more realistic models where the backbone has a finite volume, which is necessary for treating coassembled bottlebrushes. We find that the way in which the linear charge density or the grafting density is regulated is important. Typically, the stiffening effect is reduced when there is freedom for these quantities to adapt to the curvature stresses. Electrostatically driven coassembled bottlebrushes, however, are relatively stiff because the chains have a low tendency to escape from the compressed regions and the electrostatic binding force is largest in the convex part. For coassembled bottlebrushes, the induced persistence length is a nonmonotonic function of the polymer concentration: For low polymer concentrations, the stiffening grows quadratically with coverage; for semidilute polymer concentrations, the brush chains retract and regain their Gaussian size. When doing so, they lose their induced persistence length contribution. Our results correlate well with observed physical characteristics of electrostatically driven coassembled DNA-bioengineered protein-polymer bottlebrushes.

  15. Creation of Magnetic Fields by Electrostatic and Thermal Fluctuations

    International Nuclear Information System (INIS)

    Saleem, Hamid

    2009-01-01

    It is pointed out that the electrostatic and thermal fluctuations are the main source of magnetic fields in unmagnetized inhomogeneous plasmas. The unmagnetized inhomogeneous plasmas can support a low frequency electromagnetic ion wave as a normal mode like Alfven wave of magnetized plasmas. But this is a coupled mode produced by the mixing of longitudinal and transverse components of perturbed electric field due to density inhomogeneity. The ion acoustic wave does not remain electrostatic in non-uniform plasmas. On the other hand, a low frequency electrostatic wave can also exist in the pure electron plasmas and it couples with ion acoustic wave when ions are dynamic. These waves can become unstable when density and temperature gradients are parallel to each other as can be the case of laser plasmas and is the common situation in stellar cores. The main instability condition for the electrostatic and electromagnetic modes is the same (2/3)κ n T (where κ n and κ T are inverse of the scale lengths of gradients of density and electron temperature, respectively). This indicates that the electrostatic and magnetic field fluctuations are strongly coupled in unmagnetized nonuniform plasmas.

  16. Physical and chemical test results of electrostatic safe flooring materials

    Science.gov (United States)

    Gompf, R. H.

    1988-01-01

    This test program was initiated because a need existed at the Kennedy Space Center (KSC) to have this information readily available to the engineer who must make the choice of which electrostatic safe floor to use in a specific application. The information, however, should be of value throughout both the government and private industry in the selection of a floor covering material. Included are the test results of 18 floor covering materials which by test evaluation at KSC are considered electrostatically safe. Tests were done and/or the data compiled in the following areas: electrostatics, flammability, hypergolic compatibility, outgassing, floor type, material thickness, and available colors. Each section contains the test method used to gather the data and the test results.

  17. A non-electrostatic spacer for aerosol delivery

    DEFF Research Database (Denmark)

    Bisgaard, H; Anhøj, J; Klug, B

    1995-01-01

    to 6 years, suspected to have asthma the non-electrostatic spacer delivered a mean total dose of budesonide aerosol of 39% of the nominal dose, which was significantly higher than the Babyhaler (28%), the Nebuhaler (21%), and the AeroChamber (19%). These differences were most pronounced in children......A pear shaped non-electrostatic spacer, composed of steel with a volume of 250 ml and equipped with a facemask containing integrated inlet and outlet valves for inspiration and expiration, was compared with three plastic spacers. The plastic spacers were primed with repeated puffs from a budesonide...... was 27 seconds and independent of the use of p-MDI. In vitro the maximum dose of budesonide from a p-MDI, expressed as a percentage of the nominal dose, was 56% from the non-electrostatic spacer, 61% from the Nebuhaler, 45% from the Babyhaler, and 30% from the AeroChamber. In 124 children, age 6 months...

  18. Repetitive control of an electrostatic microbridge actuator: theory and simulation

    International Nuclear Information System (INIS)

    Zhao, Haiyu; Rahn, Christopher D

    2010-01-01

    Electrostatic microactuators are used extensively in MEMS sensors, RF switches and microfluidic pumps. The high bandwidth operation required by these applications complicates the implementation of feedback controllers. This paper designs, proves stability and simulates a feedforward repetitive controller for an electrostatic microbridge. High residual stress creates tension in the microbridge that dominates bending stiffness so a pinned string model with uniform electrostatic force loading is used for model-based control. The control objective is to force the microbridge displacement to follow prescribed spatial and periodic time trajectories. Viscous damping ensures boundedness of the distributed transverse displacement in response to bounded inputs. The average displacement is measured by capacitive sensing and processed offline using a repetitive control algorithm that updates a high speed waveform generator's parameters. Simulations show that the performance depends on the amount of damping. With less than 1% damping in a representative microbridge structure, repetitive control reduces the midspan displacement overshoot by 83%

  19. Inertial electrostatic confinement I(IEC) neutron sources

    International Nuclear Information System (INIS)

    Nebel, R.A.; Barnes, D.C.; Caramana, E.J.; Janssen, R.D.; Nystrom, W.D.; Tiouririne, T.N.; Trent, B.C.; Miley, G.H.; Javedani, J.

    1995-01-01

    Inertial Electrostatic Confinement (IEC) is one of the earliest plasma confinement concepts, having first been suggested by P.T. Farnsworth in the 1950s. The concept involves a simple apparatus of concentric spherical electrostatic grids or a combination of grids and magnetic fields. An electrostatic structure is formed from the confluence of electron or ion beams. Gridded IEC systems have demonstrated neutron yields as high as 2*10 [10]. neutrons/sec in steady state. These systems have considerable potential as small, inexpensive, portable neutron sources for assaying applications. Neutron tomography is also a potential application. This paper discusses the IEC concept and how it can be adapted to a steady-state assaying source and an intense pulsed neutron source. Theoretical modeling and experimental results are presented

  20. Atomic processes in Inertial Electrostatic Confinement (IEC) devices

    International Nuclear Information System (INIS)

    Nebel, R.A.; Turner, L.; Tiouririne, T.N.; Barnes, D.C.; Nystrom, W.D.; Bussard, R.W.; Miley, G.H.; Javedani, J.; Yamamoto, Y.

    1993-01-01

    Inertial Electrostatic Confinement (IEC) is one of the earliest plasma confinement concepts, having first been suggested by P. T. Farnsworth in the 1950s. The concept involves a simple apparatus of concentric spherical electrostatic grids or a combination of grids and magnetic fields. An electrostatic structure is formed from the confluence of electron or ion beams. Gridded IEC systems have demonstrated neutron yields as high as 2*10 10 neutrons/sec. These systems have considerable potential as small, inexpensive, portable neutron sources for assaying applications. Neutron tomography is also a potential application. Atomic physics effects strongly influence the performance of all of these systems. Important atomic effects include elastic scattering, ionization, excitation, and charge exchange. This paper discusses how an IEC system is influenced by these effects and how to design around them. Theoretical modeling and experimental results are presented