WorldWideScience

Sample records for alternating current transmission

  1. Transient analysis for alternating over-current characteristics of HTSC power transmission cable

    Science.gov (United States)

    Lim, S. H.; Hwang, S. D.

    2006-10-01

    In this paper, the transient analysis for the alternating over-current distribution in case that the over-current was applied for a high-TC superconducting (HTSC) power transmission cable was performed. The transient analysis for the alternating over-current characteristics of HTSC power transmission cable with multi-layer is required to estimate the redistribution of the over-current between its conducting layers and to protect the cable system from the over-current in case that the quench in one or two layers of the HTSC power cable happens. For its transient analysis, the resistance generation of the conducting layers for the alternating over-current was reflected on its equivalent circuit, based on the resistance equation obtained by applying discrete Fourier transform (DFT) for the voltage and the current waveforms of the HTSC tape, which comprises each layer of the HTSC power transmission cable. It was confirmed through the numerical analysis on its equivalent circuit that after the current redistribution from the outermost layer into the inner layers first happened, the fast current redistribution between the inner layers developed as the amplitude of the alternating over-current increased.

  2. Analysis of operations and cyber security policies for a system of cooperating Flexible Alternating Current Transmission System (FACTS) devices.

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Laurence R.; Tejani, Bankim; Margulies, Jonathan; Hills, Jason L.; Richardson, Bryan T.; Baca, Micheal J.; Weiland, Laura

    2005-12-01

    Flexible Alternating Current Transmission Systems (FACTS) devices are installed on electric power transmission lines to stabilize and regulate power flow. Power lines protected by FACTS devices can increase power flow and better respond to contingencies. The University of Missouri Rolla (UMR) is currently working on a multi-year project to examine the potential use of multiple FACTS devices distributed over a large power system region in a cooperative arrangement in which the FACTS devices work together to optimize and stabilize the regional power system. The report describes operational and security challenges that need to be addressed to employ FACTS devices in this way and recommends references, processes, technologies, and policies to address these challenges.

  3. Alternating current loss calculation in a high-TC superconducting transmission cable considering the magnetic field distribution

    International Nuclear Information System (INIS)

    Noji, H; Haji, K; Hamada, T

    2003-01-01

    We have calculated the alternating current (ac) losses of a 114 MVA high-T C superconducting (HTS) transmission cable using an electric-circuit (EC) model. The HTS cable is fabricated by Tokyo Electric Power Company and Sumitomo Electric Industries, Ltd. The EC model is comprised of a resistive part and an inductive part. The resistive part is obtained by the approximated Norris equation for a HTS tape. The Norris equation indicates hysteresis losses due to self-fields. The inductive part has two components, i.e. inductances related to axial fields and those related to circumferential fields. The layer currents and applied fields of each layer were calculated by the EC model. By using both values, the ac losses of the one-phase HTS cable were obtained by calculation considering the self-field, the axial field and the circumferential field of the HTS tape. The measured ac loss transporting 1 kA rms is 0.7 W m -1 ph -1 , which is equal to the calculation. The distribution of each layer loss resembles in shape the distribution of the circumferential field in each layer, which indicates that the circumferential fields strongly influence the ac losses of the HTS cable

  4. Alternative approaches to transmission investment

    Energy Technology Data Exchange (ETDEWEB)

    Welch, J.L. [International Transmission Co., Detroit, MI (United States)

    2004-07-01

    The International Transmission Company (ITC) is an independent power transmission company that owns, operates and maintains the high voltage transmission system in southeastern Michigan. The company's current focus is on investing in the transmission infrastructure to improve reliability, relieve congestion, improve access to generation and reduce energy costs for consumers. There is a need for investment in power transmission. Trends indicate that power transactions are on the rise while transmission investment is lagging because pricing protocols are inadequate and there is no regional tariff mechanism to allocate the benefits of new investment. The presentation reviewed the applicability of FTRs to transmission owners and the pitfalls of participant funding pricing. It also outlined the regional benefit allocation mechanism (RBAM) with an illustrative example. It was concluded that existing pricing policies must be improved to address the growing need for transmission investment. RBAM is needed to help investors recover costs from project beneficiaries. figs.

  5. Alternative approaches to transmission investment

    Energy Technology Data Exchange (ETDEWEB)

    Vlahos, P. [Ontario Energy Board, Toronto, ON (Canada)

    2004-07-01

    The current regulatory framework at the Ontario Energy Board (OEB) was outlined with reference to the 10-year outlook of the Independent Electricity Market Operator (IMO). Power transmitters currently respond to the IMO's outlook, while the OEB approves applications and cost recovery in rates. The Working Group on Congestion has recommended that the IMO produce a 10-year resource plan, that transmitters produce a 10-year expansion plan, and that the OEB develop a framework for project assessment and rate relief. The Task Force has concluded that merchant transmission is not proven, that transmission is an essential public infrastructure, and that regulatory responsibilities and approval processes should be clarified and streamlined. It was noted that the OEB's approach to regulation should be consistent, clear, predictable, fair, timely and in the public interest.

  6. Alternative approaches to transmission investment

    Energy Technology Data Exchange (ETDEWEB)

    Thon, S. [AltaLink Management Ltd., Calgary, AB (Canada)

    2004-07-01

    AltaLink is Canada's first stand-alone power transmission company, serving all major centres in Alberta and 85 per cent of Alberta's population. It has more than $1 billion in assets, 11,500 km of transmission lines and 300 substations. It was noted that there has not been any significant investment in power transmission in Alberta for the past 20 years, partly because transmission assets have a very long lifespan. The new role of the power grid is to ensure reliability, safety, efficiency, market effectiveness and supply diversity. The benefits and costs of AltaLink's 500 kV North-South upgrade project were outlined. It was noted that a healthy transmission system is the basis for economic growth throughout the province and for the development of Alberta's resource base. The transmission policy in Alberta endorses that all consumers pay postage stamp tariffs. It also promotes a proactive plan for transmission projects, the time to maximum rate (TMR) in limited cases only, a congestion-free grid under normal conditions, the financial commitment of generators, specific time limits on permitting processes, and regional interconnections to benefit all customers. tabs., figs.

  7. Current issues and strategies for transmission planning

    Energy Technology Data Exchange (ETDEWEB)

    Isaacs, A.L. [Electranix, Winnipeg, MB (Canada); Rajapakse, A. [Manitoba Univ., Winnipeg, MB (Canada)

    2008-07-01

    Following the widespread deregulation of the electric power industry in the early 1990s, significant changes occurred in the regulatory and planning environments of the industry. Several regions of North America remain fully or partially regulated in the traditional sense including most Canadian provinces, except for Alberta and Ontario. Although the Mexican system has separate generation and transmission companies and current restructuring efforts are underway, all companies are state-owned, and private investment in energy is heavily constrained by the Mexican constitution. In these regulated regions, traditional generation and transmission expansion planning methods remain in use. This paper presented an overview of current trends in transmission planning strategies that have evolved in response to the restructuring of the power industry, and a conceptual framework of a procedure that would guide planners faced with the challenges of incorporating large scale wind generation in deregulated environments. The paper provided background information on the effect of deregulation on transmission planning. Planning strategies that were discussed included quantifying risk to help identify best alternatives; use of reference systems to estimate generator costs and reduce uncertainty; project based transmission expansion; transmission construction ahead of generation; and generation ahead of transmission. The impact of wind on transmission planning as well as future work addressing challenges posed by wind were also addressed. Research is continuing in this area to illustrate the concepts proposed through a detailed case study. 15 refs., 2 figs.

  8. Alternative electrical transmission systems and their environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Schiefelbein, G.F.

    1977-08-01

    A general description is provided of electrical transmission systems as an aid in determining their environmental impacts. Alternating current, direct current, overhead systems, underground systems, and water crossings are treated. The cost, performance, reliability, safety, and environmental impact of these systems are compared.

  9. Phasor Alternatives to Friis’ Transmission Equation

    DEFF Research Database (Denmark)

    Franek, Ondrej

    2018-01-01

    Two alternatives to Friis’ transmission equation in terms of phasor voltage waves are presented. In one formulation antennas are characterized by the complex effective length vectors. An additional form introducing field gain, that serves effectively as a phasor counterpart to the power gain......, is proposed. Both forms show the same degree of symmetry and modularity as the original Friis’ equation, but thanks to using phasors instead of power quantities they allow for superposition of fields or voltages. Although the new transmission equations are formulated in frequency domain, they also constitute...

  10. Alternating current for the West

    International Nuclear Information System (INIS)

    2006-01-01

    In the framework of the reactor EPR construction in the Manche, the authors wonder on the pertinence of this energy choice for the economy and the environment of the West France. They show that there is an alternative to this choice. In a first part a state of the situation concerning the electricity supply and demand in the region is detailed. Then from the local potential of renewable electric power production and the electricity conservation, they propose many concrete actions. (A.L.B.)

  11. Alternating current long range alpha particle detector

    International Nuclear Information System (INIS)

    MacArthur, D.W.; McAtee, J.L.

    1993-01-01

    An alpha particle detector, utilizing alternating currents, which is capable of detecting alpha particles from distinct sources. The use of alternating currents allows use of simpler ac circuits which, in turn, are not susceptible to dc error components. It also allows the benefit of gas gain, if desired. In the invention, a voltage source creates an electric field between two conductive grids, and between the grids and a conductive enclosure. Air containing air ions created by collision with alpha particles is drawn into the enclosure and detected. In some embodiments, the air flow into the enclosure is interrupted, creating an alternating flow of ions. In another embodiment, a modulated voltage is applied to the grid, also modulating the detection of ions

  12. Transcranial Alternating Current Stimulation Attenuates Neuronal Adaptation.

    Science.gov (United States)

    Kar, Kohitij; Duijnhouwer, Jacob; Krekelberg, Bart

    2017-03-01

    We previously showed that brief application of 2 mA (peak-to-peak) transcranial currents alternating at 10 Hz significantly reduces motion adaptation in humans. This is but one of many behavioral studies showing that weak currents applied to the scalp modulate neural processing. Transcranial stimulation has been shown to improve perception, learning, and a range of clinical symptoms. Few studies, however, have measured the neural consequences of transcranial current stimulation. We capitalized on the strong link between motion perception and neural activity in the middle temporal (MT) area of the macaque monkey to study the neural mechanisms that underlie the behavioral consequences of transcranial alternating current stimulation. First, we observed that 2 mA currents generated substantial intracranial fields, which were much stronger in the stimulated hemisphere (0.12 V/m) than on the opposite side of the brain (0.03 V/m). Second, we found that brief application of transcranial alternating current stimulation at 10 Hz reduced spike-frequency adaptation of MT neurons and led to a broadband increase in the power spectrum of local field potentials. Together, these findings provide a direct demonstration that weak electric fields applied to the scalp significantly affect neural processing in the primate brain and that this includes a hitherto unknown mechanism that attenuates sensory adaptation. SIGNIFICANCE STATEMENT Transcranial stimulation has been claimed to improve perception, learning, and a range of clinical symptoms. Little is known, however, how transcranial current stimulation generates such effects, and the search for better stimulation protocols proceeds largely by trial and error. We investigated, for the first time, the neural consequences of stimulation in the monkey brain. We found that even brief application of alternating current stimulation reduced the effects of adaptation on single-neuron firing rates and local field potentials; this mechanistic

  13. Tiling by rectangles and alternating current

    KAUST Repository

    Prasolov, M. V.

    2011-04-01

    This paper is on tilings of polygons by rectangles. A celebrated physical interpretation of such tilings by R.L. Brooks, C.A.B. Smith, A.H. Stone and W.T. Tutte uses direct-current circuits. The new approach of this paper is an application of alternating-current circuits. The following results are obtained: •a necessary condition for a rectangle to be tilable by rectangles of given shapes;•a criterion for a rectangle to be tilable by rectangles similar to it but not all homothetic to it;•a criterion for a "generic" polygon to be tilable by squares. These results generalize those of C. Freiling, R. Kenyon, M. Laczkovich, D. Rinne, and G. Szekeres. © 2010 Elsevier Inc.

  14. Stability of alternating current gliding arcs

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Salewski, Mirko; Leipold, Frank

    2014-01-01

    on Ohm’s law indicates that the critical length of alternating current (AC) gliding arc discharge columns can be larger than that of a corresponding direct current (DC) gliding arc. This finding is supported by previously published images of AC and DC gliding arcs. Furthermore, the analysis shows......A gliding arc is a quenched plasma that can be operated as a non-thermal plasma at atmospheric pressure and that is thus suitable for large-scale plasma surface treatment. For its practical industrial use the discharge should be extended stably in ambient air. A simple analytical calculation based...... that the critical length can be increased by increasing the AC frequency, decreasing the serial resistance and lowering the gas flow rate. The predicted dependence of gas flow rate on the arc length is experimentally demonstrated. The gap width is varied to study an optimal electrode design, since the extended non...

  15. A current controlled variable delay superconducting transmission line

    International Nuclear Information System (INIS)

    Anlage, S.M.; Snortland, H.J.; Beasley, M.R.

    1989-01-01

    The authors present a device concept for a current-controlled variable delay for superconducting transmission line. The device makes use of the change in kinetic inductance of a superconducting transmission line under the application of a DC bias current. The relevant materials parameters and several promising superconducting materials have been identified

  16. Alternating current electrocoagulation for Superfund site remediation

    International Nuclear Information System (INIS)

    Farrell, C.W.

    1991-01-01

    A study is being conducted by Electro-Pure Systems, Inc. (EPS) under the Emerging Technology portion of the U.S. Environmental Protection Agency's (EPA's) Superfund Innovative Technology Evaluation (SITE) Program to study alternating current electrocoagulation for Superfund site remediation. Alternating current electrocoagulation has proven to be effective in agglomerating and removing colloidal solids, metals and certain organic contaminants from surrogate soils prepared from the US EPA's Synthetic Soil Matrix. Treatments under a wide range of operating conditions have enabled the optimum parameter settings to be established for multiple phase separation. Electrocoagulation enables appreciably enhanced filtration and dewatering rates to be realized for metals- and diesel fuel-spiked surrogate soil slurries; such enhancements are prompted by growth in the mean particle size of the clays and particulates from typically < 10 microns to as much as 150 microns depending on the degree of electrocoagulation. Reduction in the total suspended solids content of clays in all slurries in excess of 90% can routinely be achieved. Bench-scale experiments of the metals-spiked surrogate soils indicate that electrocoagulation preferentially concentrates soluble metals into the sludge phase; excellent metals separation (Pb, Cr, Cu, Cd) can be realized. Experiments on surrogate wastes spiked with volatile organics suggest that this technology is not capable of effecting good volatile extractions from the aqueous phase. Reductions in excess of 80% in the total organic carbon (TOC) content of the diesel fuel-spiked surrogates can, however, be achieved

  17. Direct current contamination of kilohertz frequency alternating current waveforms.

    Science.gov (United States)

    Franke, Manfred; Bhadra, Niloy; Bhadra, Narendra; Kilgore, Kevin

    2014-07-30

    Kilohertz frequency alternating current (KHFAC) waveforms are being evaluated in a variety of physiological settings because of their potential to modulate neural activity uniquely when compared to frequencies in the sub-kilohertz range. However, the use of waveforms in this frequency range presents some unique challenges regarding the generator output. In this study we explored the possibility of undesirable contamination of the KHFAC waveforms by direct current (DC). We evaluated current- and voltage-controlled KHFAC waveform generators in configurations that included a capacitive coupling between generator and electrode, a resistive coupling and combinations of capacitive with inductive coupling. Our results demonstrate that both voltage- and current-controlled signal generators can unintentionally add DC-contamination to a KHFAC signal, and that capacitive coupling is not always sufficient to eliminate this contamination. We furthermore demonstrated that high value inductors, placed in parallel with the electrode, can be effective in eliminating DC-contamination irrespective of the type of stimulator, reducing the DC contamination to less than 1 μA. This study highlights the importance of carefully designing the electronic setup used in KHFAC studies and suggests specific testing that should be performed and reported in all studies that assess the neural response to KHFAC waveforms. Published by Elsevier B.V.

  18. A Stretchable Alternating Current Electroluminescent Fiber

    Directory of Open Access Journals (Sweden)

    Dan Hu

    2018-01-01

    Full Text Available Flexible, stretchable electroluminescent fibers are of significance to meet the escalating requirements of increasing complexity and multifunctionality of smart electronics. We report a stretchable alternating current electroluminescent (ACEL fiber by a low-cost and all solution-processed scalable process. The ACEL fiber provides high stretchability, decent light-emitting performance, with excellent stability and nearly zero hysteresis. It can be stretched up to 80% strain. Our ACEL fiber device maintained a stable luminance for over 6000 stretch-release cycles at 50% strain. The mechanical stretchability and optical stability of our ACEL fiber device provides new possibilities towards next-generation stretchable displays, electronic textiles, advanced biomedical imaging and lighting, conformable visual readouts in arbitrary shapes, and novel health-monitoring devices.

  19. Transcranial alternating current stimulation (tACS

    Directory of Open Access Journals (Sweden)

    Andrea eAntal

    2013-06-01

    Full Text Available Transcranial alternating current stimulation (tACS seems likely to open a new era of the field of noninvasive electrical stimulation of the human brain by directly interfering with cortical rhythms. It is expected to synchronize (by one single resonance frequency or desynchronize (e.g. by the application of several frequencies cortical oscillations. If applied long enough it may cause neuroplastic effects. In the theta range it may improve cognition when applied in phase. Alpha rhythms could improve motor performance, whereas beta intrusion may deteriorate them. TACS with both alpha and beta frequencies has a high likelihood to induce retinal phosphenes. Gamma intrusion can possibly interfere with attention. Stimulation in the ripple range induces intensity dependent inhibition or excitation in the motor cortex most likely by entrainment of neuronal networks, whereas stimulation in the low kHz range induces excitation by neuronal membrane interference. TACS in the 200 kHz range may have a potential in oncology.

  20. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    Energy Technology Data Exchange (ETDEWEB)

    Litzenberger, Wayne; Lava, Val

    1994-08-01

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  1. Overview of current and alternative slaughter practices

    Directory of Open Access Journals (Sweden)

    Troeger K.

    2004-01-01

    Full Text Available The conventional cattle slaughtering process includes some critical stages where a dissemination of Specified Risk Material (SRM: brain, spinal cord within or onto the carcass and within the slaughterhouse environment can occur. These processes are captive bolt stunning, removal of the head and first of all carcass splitting (sawing the spine lengthways. Captive bolt (CB stunning results in massive brain tissue damage with bleeding, and in some cases brain tissue also emerges from the CB hole. As the heart is still functioning, there is a risk of brain tissue particles being transferred v i a the blood flow to heart and lungs or even in the whole carcass. This contamination risk is actually assessed to be low, but a continuing leakage of Central Nervous System (CNS material from the captive bolt aperture in the further slaughter process may lead to direct and indirect contamination of carcass, meat and equipment. Therefore alternative stunning methods like electrical stunning or concussion stunning are discussed. A further critical point is the treatment of the head. When the head is removed, the spinal cord is cut with a knife. There is a danger of cross contamination due to spinal protein that may adhere to the knife and because of liquid cerebralis, which leaks from the foramen occipitale magnum. Further head cleaning with hand-held hoses following skinning also includes the danger of cross contamination from cleaning water or aerosol. Therefore measures regarding the safe handling of head and harvesting of head meat are proposed. The most critical point in terms of contamination of the meat surface with SRM is the currently common practise of sawing the spine vertically in the middle with hand-guided belt-type saws. A m i x t u r e of sawing residues and rinsing water (“sawing sludge” collects in the housing of the saw, and if it contains infectious material this leads to contamination of the subsequent carcasses. The most promising

  2. Tiling by rectangles and alternating current

    KAUST Repository

    Prasolov, M. V.; Skopenkov, Mikhail

    2011-01-01

    This paper is on tilings of polygons by rectangles. A celebrated physical interpretation of such tilings by R.L. Brooks, C.A.B. Smith, A.H. Stone and W.T. Tutte uses direct-current circuits. The new approach of this paper is an application

  3. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current-limiting matrix.

  4. Microwave power - An energy transmission alternative for the year 2000

    Science.gov (United States)

    Nalos, E.; Sperber, R.

    1980-01-01

    Recent technological advances related to the feasibility of efficient RF-dc rectification make it likely that by the year 2000 the transmission of power through space will have become a practical reality. Proposals have been made to power helicopters, aircraft, balloons, and rockets remotely. Other proposals consider the transfer of power from point to point on earth via relay through space or a transmission of power from large power sources in space. Attention has also been given to possibilities regarding the transmission of power between various points in the solar system. An outline is provided of the microwave power transmission system envisaged for the solar power satellite, taking into account the transmitting antenna, the receiver on earth, aspects of beam formation and control, transmitter options, the receiving antenna design, and cost and efficiency considerations.

  5. Experimental investigation of alternative transmission functions: Quantitative evidence for the importance of nonlinear transmission dynamics in host-parasite systems.

    Science.gov (United States)

    Orlofske, Sarah A; Flaxman, Samuel M; Joseph, Maxwell B; Fenton, Andy; Melbourne, Brett A; Johnson, Pieter T J

    2018-05-01

    Understanding pathogen transmission is crucial for predicting and managing disease. Nonetheless, experimental comparisons of alternative functional forms of transmission remain rare, and those experiments that are conducted are often not designed to test the full range of possible forms. To differentiate among 10 candidate transmission functions, we used a novel experimental design in which we independently varied four factors-duration of exposure, numbers of parasites, numbers of hosts and parasite density-in laboratory infection experiments. We used interactions between amphibian hosts and trematode parasites as a model system and all candidate models incorporated parasite depletion. An additional manipulation involving anaesthesia addressed the effects of host behaviour on transmission form. Across all experiments, nonlinear transmission forms involving either a power law or a negative binomial function were the best-fitting models and consistently outperformed the linear density-dependent and density-independent functions. By testing previously published data for two other host-macroparasite systems, we also found support for the same nonlinear transmission forms. Although manipulations of parasite density are common in transmission studies, the comprehensive set of variables tested in our experiments revealed that variation in density alone was least likely to differentiate among competing transmission functions. Across host-pathogen systems, nonlinear functions may often more accurately represent transmission dynamics and thus provide more realistic predictions for infection. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  6. Electric and magnetic field reduction by alternative transmission line options

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, J.R. (Power Technologies, Inc., Schenectady, NY (United States)); Dale, S.J. (Oak Ridge National Lab., TN (United States)); Klein, K.W. (Energetics, Inc., Columbia, MD (United States))

    1991-01-01

    Ground level electric, and more recently magnetic, fields from overhead power transmission lines are increasingly important considerations in right of way specification, with states setting or planning to set edge of right of way limits. Research has been conducted in high phase order power transmission wherein six of twelve phases are used to transmit power in less physical space and with reduced electrical environmental effects than conventional designs. The first magnetic field testing, as reported in this paper, has verified predictive methods for determination of magnetic fields from high phase order lines. Based on these analytical methods, field profiles have been determined for lines of different phase order of comparable power capacity. Potential advantages of high phase order as a means of field mitigation are discussed. 10 refs., 12 figs., 3 tabs.

  7. Low-Frequency Pulsed Current Versus Kilohertz-Frequency Alternating Current: A Scoping Literature Review.

    Science.gov (United States)

    Vaz, Marco Aurélio; Frasson, Viviane Bortoluzzi

    2018-04-01

    To compare the effectiveness of low-frequency pulsed current versus kilohertz-frequency alternating current in terms of evoked force, discomfort level, current intensity, and muscle fatigability; to discuss the physiological mechanisms of each neuromuscular electrical stimulation type; and to determine if kilohertz-frequency alternating current is better than low-frequency pulsed current for clinical treatment. Articles were obtained from PubMed, Scopus, Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE, and SPORTSDiscus databases using the terms Russian current or kilohertz current or alternating current or pulsed current or Aussie current and torque or discomfort or fatigue or current intensity, and through citation tracking up to July 2017. Two independent reviewers selected studies comparing the use of the 2 neuromuscular electrical stimulation currents. Studies describing maximal current intensity tolerated and the main effects of the 2 different current types on discomfort, muscle force, and fatigability were independently reviewed. Data were systematized according to (1) methodology; (2) electrical current characteristics; and (3) outcomes on discomfort level, evoked force, current intensity, and muscle fatigability. The search revealed 15 articles comparing the 2 current types. Kilohertz-frequency alternated current generated equal or less force, similar discomfort, similar current intensity for maximal tolerated neuromuscular electrical stimulation, and more fatigue compared with low-frequency pulsed current. Similar submaximal levels of evoked force revealed higher discomfort and current intensity for kilohertz-frequency alternated current compared with low-frequency pulsed current. Available evidence does not support the idea that kilohertz-frequency alternated current is better than low-frequency pulsed current for strength training and rehabilitation. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier

  8. Alternate transmission with half-duplex relaying in MIMO interference relay networks

    KAUST Repository

    Park, Seongho; Ko, Youngchai; Park, Kihong; Alouini, Mohamed-Slim

    2013-01-01

    In this paper, we consider an alternate transmission scheme for a multiple-input multiple-output interference relay channel where multiple sources transmit their own signals to their corresponding destinations via one of two relaying groups

  9. Effect of alternating and direct currents on Pseudomonas ...

    African Journals Online (AJOL)

    The test media were Muller-Hinton agar and eosin methylene blue (EMB) agar. In this research Pseudomonas aeruginosa which was isolated from patients wounds was examined with levels of alternating and direct current (AC and DC) electrical stimulation (1.5V, 3.5V, 5.5V and 10V) to see if these currents could inhibit P.

  10. Tailoring of electron flow current in magnetically insulated transmission lines

    Directory of Open Access Journals (Sweden)

    J. P. Martin

    2009-03-01

    Full Text Available It is desirable to optimize (minimizing both the inductance and electron flow the magnetically insulated vacuum sections of low impedance pulsed-power drivers. The goal of low inductance is understandable from basic efficiency arguments. The goal of low electron flow results from two observations: (1 flowing electrons generally do not deliver energy to (or even reach most loads, and thus constitute a loss mechanism; (2 energetic electrons deposited in a small area can cause anode damage and anode plasma formation. Low inductance and low electron flow are competing goals; an optimized system requires a balance of the two. While magnetically insulated systems are generally forgiving, there are times when optimization is crucial. For example, in large pulsed-power drivers used to energize high energy density physics loads, the electron flow as a fraction of total current is small, but that flow often reaches the anode in relatively small regions. If the anode temperature becomes high enough to desorb gas, the resulting plasma initiates a gap closure process that can impact system performance. Magnetic-pressure driven (z pinches and material equation of state loads behave like a fixed inductor for much of the drive pulse. It is clear that neither fixed gap nor constant-impedance transmission lines are optimal for driving inductive loads. This work shows a technique for developing the optimal impedance profile for the magnetically insulated section of a high-current driver. Particle-in-cell calculations are used to validate the impedance profiles developed in a radial disk magnetically insulated transmission line geometry. The input parameters are the spacing and location of the minimum gap, the effective load inductance, and the desired electron flow profile. The radial electron flow profiles from these simulations are in good agreement with theoretical predictions when driven at relatively high voltage (i.e., V≥2  MV.

  11. Method and system for a gas tube-based current source high voltage direct current transmission system

    Science.gov (United States)

    She, Xu; Chokhawala, Rahul Shantilal; Bray, James William; Sommerer, Timothy John; Zhou, Rui; Zhang, Di

    2017-08-29

    A high-voltage direct-current (HVDC) transmission system includes an alternating current (AC) electrical source and a power converter channel that includes an AC-DC converter electrically coupled to the electrical source and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and the DC-AC inverter each include a plurality of legs that includes at least one switching device. The power converter channel further includes a commutating circuit communicatively coupled to one or more switching devices. The commutating circuit is configured to "switch on" one of the switching devices during a first portion of a cycle of the H-bridge switching circuits and "switch off" the switching device during a second portion of the cycle of the first and second H-bridge switching circuits.

  12. Reduction of sound transmission through fuselage walls by alternate resonance tuning (A.R.T.)

    Science.gov (United States)

    Bliss, Donald B.; Gottwald, James A.

    1989-01-01

    The ability of alternate resonance tuning (ART) to block sound transmission through light-weight flexible paneled walls by controlling the dynamics of the wall panels is considered. Analytical results for sound transmission through an idealized panel wall illustrate the effect of varying system parameters and show that one or more harmonics of the incident sound field can be cancelled by the present method. Experimental results demonstrate that very large transmission losses with reasonable bandwidths can be achieved by a simple ART panel barrier in a duct.

  13. Alternating currents and shear waves in viscous electronics

    Science.gov (United States)

    Semenyakin, M.; Falkovich, G.

    2018-02-01

    Strong interaction among charge carriers can make them move like viscous fluid. Here we explore alternating current (ac) effects in viscous electronics. In the Ohmic case, incompressible current distribution in a sample adjusts fast to a time-dependent voltage on the electrodes, while in the viscous case, momentum diffusion makes for retardation and for the possibility of propagating slow shear waves. We focus on specific geometries that showcase interesting aspects of such waves: current parallel to a one-dimensional defect and current applied across a long strip. We find that the phase velocity of the wave propagating along the strip respectively increases/decreases with the frequency for no-slip/no-stress boundary conditions. This is so because when the frequency or strip width goes to zero (alternatively, viscosity go to infinity), the wavelength of the current pattern tends to infinity in the no-stress case and to a finite value in a general case. We also show that for dc current across a strip with a no-stress boundary, there are only one pair of vortices, while there is an infinite vortex chain for all other types of boundary conditions.

  14. Alternating-current ohmic heating in a helical stellarator

    International Nuclear Information System (INIS)

    Funato, Yasuyuki; Kitajima, Sumio; Watanabe, Hiroshige

    1984-01-01

    A toroidal plasma is generated successively by an alternating-current discharge in a helical or non-planar torus, and is confined quasi-stationarily by a longitudinal magnetic field with a high rotational transform angle. The particle confinement time obtained experimentally is estimated to be 3-10 ms, which is compared with theoretical values for this system, and is much larger than the time of pulse interval of the plasma production. (author)

  15. Ebola Virus Shedding and Transmission: Review of Current Evidence.

    Science.gov (United States)

    Vetter, Pauline; Fischer, William A; Schibler, Manuel; Jacobs, Michael; Bausch, Daniel G; Kaiser, Laurent

    2016-10-15

     The magnitude of the 2013-2016 Ebola virus disease outbreak in West Africa was unprecedented, with >28 500 reported cases and >11 000 deaths. Understanding the key elements of Ebola virus transmission is necessary to implement adequate infection prevention and control measures to protect healthcare workers and halt transmission in the community.  We performed an extensive PubMed literature review encompassing the period from discovery of Ebola virus, in 1976, until 1 June 2016 to evaluate the evidence on modes of Ebola virus shedding and transmission.  Ebola virus has been isolated by cell culture from blood, saliva, urine, aqueous humor, semen, and breast milk from infected or convalescent patients. Ebola virus RNA has been noted in the following body fluids days or months after onset of illness: saliva (22 days), conjunctiva/tears (28 days), stool (29 days), vaginal fluid (33 days), sweat (44 days), urine (64 days), amniotic fluid (38 days), aqueous humor (101 days), cerebrospinal fluid (9 months), breast milk (16 months [preliminary data]), and semen (18 months). Nevertheless, the only documented cases of secondary transmission from recovered patients have been through sexual transmission. We did not find strong evidence supporting respiratory or fomite-associated transmission. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  16. The transmission process of financial crises across the emerging markets: an alternative consideration

    OpenAIRE

    Abdurrahman, Korkmaz

    2012-01-01

    This paper offers an alternative consideration for the transmission process of financial crises across emerging markets. Here, we hypothesized that the interdependence effect could weaken, even disappear completely, and veer during a crisis period as a result of the contagion process. The importance of this hypothesis for the policy implication is also highlighted because it can be validated for many cases by our data.

  17. Transcranial Alternating Current Stimulation (tACS Mechanisms and Protocols

    Directory of Open Access Journals (Sweden)

    Amir V. Tavakoli

    2017-09-01

    Full Text Available Perception, cognition and consciousness can be modulated as a function of oscillating neural activity, while ongoing neuronal dynamics are influenced by synaptic activity and membrane potential. Consequently, transcranial alternating current stimulation (tACS may be used for neurological intervention. The advantageous features of tACS include the biphasic and sinusoidal tACS currents, the ability to entrain large neuronal populations, and subtle control over somatic effects. Through neuromodulation of phasic, neural activity, tACS is a powerful tool to investigate the neural correlates of cognition. The rapid development in this area requires clarity about best practices. Here we briefly introduce tACS and review the most compelling findings in the literature to provide a starting point for using tACS. We suggest that tACS protocols be based on functional brain mechanisms and appropriate control experiments, including active sham and condition blinding.

  18. High voltage direct current transmission converters, systems and DC grids

    CERN Document Server

    Jovcic, Dragan

    2015-01-01

    This comprehensive reference guides the reader through all HVDC technologies, including LCC (Line Commutated Converter), 2-level VSC and VSC HVDC based on modular multilevel converters (MMC) for an in-depth understanding of converters, system level design, operating principles and modeling. Written in a tutorial style, the book also describes the key principles of design, control, protection and operation of DC transmission grids, which will be substantially different from the practice with AC transmission grids. The first dedicated reference to the latest HVDC technologies and DC grid developments; this is an essential resource for graduate students and researchers as well as engineers and professionals working on the design, modeling and operation of DC grids and HVDC.

  19. Self-commutated high-voltage direct current transmission with DC circuit breakers. Backbone for the energy policy turnaround; Selbstgefuehrte Hochspannungs-Gleichstromuebertragung mit DC-Leistungsschalter. Rueckgrat fuer die Energiewende

    Energy Technology Data Exchange (ETDEWEB)

    Goerner, Raphael [ABB AG, Mannheim (Germany). Marketing und Vertrieb, Geschaeftsbereich Grid Systems

    2013-06-01

    The 'current war' between direct current and alternating current is extended by a new location. In the future, both technologies work together in order to provide a reliable power transmission in Germany and long-term in Europe. This is based on the self-guided high-voltage direct current transmission. In conjunction with direct current circuit breakers (DC circuit breaker) the power circuit breakers may help to make the transmission grids more flexible and to minimize losses.

  20. Real-time control for long ohmic alternate current discharges

    International Nuclear Information System (INIS)

    Carvalho, Ivo S.; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

    2014-01-01

    Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks

  1. Real-time control for long ohmic alternate current discharges

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ivo S., E-mail: ivoc@ipfn.ist.utl.pt; Duarte, Paulo; Fernandes, Horácio; Valcárcel, Daniel F.; Carvalho, Pedro J.; Silva, Carlos; Duarte, André S.; Neto, André; Sousa, Jorge; Batista, António J.N.; Hekkert, Tiago; Carvalho, Bernardo B.; Gomes, Rui B.

    2014-05-15

    Highlights: • 40 Alternate plasma current (AC) semi-cycles without loss of ionization, more than 1 s of operation. • AC discharges automatic control: feedback loops, time-windows control strategy, goal oriented time-windows and exception handling. • Energy deposition and Carbon radiation evolution during the AC discharges. - Abstract: The ISTTOK tokamak has a long tradition on alternate plasma current (AC) discharges, but the old control system was limiting and lacked full system integration. In order to improve the AC discharges performance the ISTTOK fast control system was updated. This control system developed on site based on the Advanced Telecommunications Computing Architecture (ATCA) standard now integrates the information gathered by all the tokamak real-time diagnostics to produce an accurate observation of the plasma parameters. The real-time actuators were also integrated, allowing a Multiple Input Multiple Output (MIMO) control environment with several synchronization strategies available. The control system software was developed in C++ on top of a Linux system with the Multi-threaded Application Real-Time executor (MARTe) Framework to synchronize the real-time code execution under a 100μs control cycle. In addition, to simplify the discharge programming, a visual Human–Machine Interface (HMI) was also developed using the BaseLib2 libraries included in the MARTe Framework. This paper presents the ISTTOK control system and the optimizations that extended the AC current discharges duration to more than 1 s, corresponding to 40 semi-cycles without apparent degradation of the plasma parameters. This upgrade allows ISTTOK to be used as a low-cost material testing facility with long time exposures to nuclear fusion relevant plasmas, comparable (in duration) with medium size tokamaks.

  2. Evaluation of DCS III Transmission Alternatives. Phase 1A report. Appendix B. Regulatory Barriers.

    Science.gov (United States)

    1980-05-26

    Resolution DK). B.1.1.5 Importance of the RR in the DCS III Study. The ITU Radio Regulation offers a means to appraise viability of the alternatives to be...interference 466-1 483 Measurement of performance by means of signal 482 Measurement of noise in actual traffic 481 Table B.l-6. Communication Satellite...Economic and technical aspects of the choice of transmission systems GAS 5 Economic conditions and tel ecommunication development GAS 6 Economic and

  3. Alternatives to animal testing: current status and future perspectives.

    Science.gov (United States)

    Liebsch, Manfred; Grune, Barbara; Seiler, Andrea; Butzke, Daniel; Oelgeschläger, Michael; Pirow, Ralph; Adler, Sarah; Riebeling, Christian; Luch, Andreas

    2011-08-01

    On the occasion of the 20th anniversary of the Center for Alternative Methods to Animal Experiments (ZEBET), an international symposium was held at the German Federal Institute for Risk Assessment (BfR) in Berlin. At the same time, this symposium was meant to celebrate the 50th anniversary of the publication of the book "The Principles of Humane Experimental Technique" by Russell and Burch in 1959 in which the 3Rs principle (that is, Replacement, Reduction, and Refinement) has been coined and introduced to foster the development of alternative methods to animal testing. Another topic addressed by the symposium was the new vision on "Toxicology in the twenty-first Century", as proposed by the US-National Research Council, which aims at using human cells and tissues for toxicity testing in vitro rather than live animals. An overview of the achievements and current tasks, as well as a vision of the future to be addressed by ZEBET@BfR in the years to come is outlined in the present paper.

  4. Persistent current and transmission probability in the Aharonov-Bohm ring with an embedded quantum dot

    International Nuclear Information System (INIS)

    Wu Suzhi; Li Ning; Jin Guojun; Ma Yuqiang

    2008-01-01

    Persistent current and transmission probability in the Aharonov-Bohm (AB) ring with an embedded quantum dot (QD) are studied using the technique of the scattering matrix. For the first time, we find that the persistent current can arise in the absence of magnetic flux in the ring with an embedded QD. The persistent current and the transmission probability are sensitive to the lead-ring coupling and the short-range potential barrier. It is shown that increasing the lead-ring coupling or the short-range potential barrier causes the suppression of the persistent current and the increasing resonance width of the transmission probability. The effect of the potential barrier on the number of the transmission peaks is also investigated. The dependence of the persistent current and the transmission probability on the magnetic flux exhibits a periodic property with period of the flux quantum

  5. Application of alternating current for dimensionally electrochemical machining

    International Nuclear Information System (INIS)

    Kacheev, M.K.; Kovalev, L.M.

    1978-01-01

    The results of comparative experimental investigations in dimensionally electrochemical machining of 1Kh18N9T steel using alternating and direct currents are presented. The effect of the electrolyte rate in the inter-electrode clearance, electrode voltage and oscillation amplitude of the electrode-tool on the metal output from the electrodes and the relief of the machined surface is studied. It is shown that the a.c. electrochemical machining permits to achieve the greater dimensional accuracy than the d.c. machining when choosing the proper voltage and electrolyte composition. It is connected with the fact that the prevailing part of the metal output is obtained in the impulse-asymmetrical regime when the inter-electrode clearance is minimum

  6. Remediation in Practicing Physicians: Current and Alternative Conceptualizations.

    Science.gov (United States)

    Bourgeois-Law, Gisèle; Teunissen, Pim W; Regehr, Glenn

    2018-04-24

    Suboptimal performance in practicing physicians is a decades-old problem. The lack of a universally accepted definition of remediation, the paucity of research on best remediation practices, and the ongoing controversy regarding the institutional responsibility for enacting and overseeing this activity suggests that the remediation of physicians is not merely a difficult problem to solve, but a problem that the community does not grapple with meaningfully. Undoubtedly, logistical and political considerations contribute to this state of affairs; however, other underlying conceptual issues may also play a role in the medical profession's difficulties in engaging with the challenges around remediation.Through a review of the medical education and other literatures, the authors examined current conceptualizations of both remediation itself and the individual being remediated, as well as how the culture of medicine influences these conceptions. The authors explored how conceptualizations of remediation and the surrounding culture might affect not only the medical community's ability to support, but also its willingness to engage with physicians in need of remediation.Viewing remediation as a means of supporting practice change-rather than as a means of redressing gaps in knowledge and skill-might be a useful alternative conceptualization, providing a good place to start exploring new avenues of research. However, moving forward will require more than simply a reconceptualizion of remediation; it will also necessitate a change in how the community views its struggling members and a change in the medical culture that currently positions professional autonomy as the foundational premise for individual practice improvement.

  7. Alternative current source based Schottky contact with additional electric field

    Science.gov (United States)

    Mamedov, R. K.; Aslanova, A. R.

    2017-07-01

    Additional electric field (AEF) in the Schottky contacts (SC) that covered the peripheral contact region wide and the complete contact region narrow (as TMBS diode) SC. Under the influence of AEF is a redistribution of free electrons produced at certain temperatures of the semiconductor, and is formed the space charge region (SCR). As a result of the superposition of the electric fields SCR and AEF occurs the resulting electric field (REF). The REF is distributed along a straight line perpendicular to the contact surface, so that its intensity (and potential) has a minimum value on the metal surface and the maximum value at a great distance from the metal surface deep into the SCR. Under the influence of AEF as a sided force the metal becomes negative pole and semiconductor - positive pole, therefore, SC with AEF becomes an alternative current source (ACS). The Ni-nSi SC with different diameters (20-1000 μm) under the influence of the AEF as sided force have become ACS with electromotive force in the order of 0.1-1.0 mV, which are generated the electric current in the range of 10-9-10-7 A, flowing through the external resistance 1000 Ohm.

  8. Ground Return Current Behaviour in High Voltage Alternating Current Insulated Cables

    Directory of Open Access Journals (Sweden)

    Roberto Benato

    2014-12-01

    Full Text Available The knowledge of ground return current in fault occurrence plays a key role in the dimensioning of the earthing grid of substations and of cable sealing end compounds, in the computation of rise of earth potential at substation sites and in electromagnetic interference (EMI on neighbouring parallel metallic conductors (pipes, handrails, etc.. Moreover, the ground return current evaluation is also important in steady-state regime since this stray current can be responsible for EMI and also for alternating current (AC corrosion. In fault situations and under some assumptions, the ground return current value at a substation site can be computed by means of k-factors. The paper shows that these simplified and approximated approaches have a lot of limitations and only multiconductor analysis can show the ground return current behaviour along the cable (not only the two end values both in steady-state regime and in short circuit occurrence (e.g., phase-to-ground and phase-to-phase-to-ground. Multiconductor cell analysis (MCA considers the cable system in its real asymmetry without simplified and approximated hypotheses. The sensitivity of ground return current on circuit parameters (cross-bonding box resistances, substation earthing resistances, soil resistivity is presented in the paper.

  9. Characteristics of alternating current hopping conductivity in DNA sequences

    International Nuclear Information System (INIS)

    Song-Shan, Ma; Hui, Xu; Huan-You, Wang; Rui, Guo

    2009-01-01

    This paper presents a model to describe alternating current (AC) conductivity of DNA sequences, in which DNA is considered as a one-dimensional (1D) disordered system, and electrons transport via hopping between localized states. It finds that AC conductivity in DNA sequences increases as the frequency of the external electric field rises, and it takes the form of ø ac (ω) ∼ ω 2 ln 2 (1/ω). Also AC conductivity of DNA sequences increases with the increase of temperature, this phenomenon presents characteristics of weak temperature-dependence. Meanwhile, the AC conductivity in an off-diagonally correlated case is much larger than that in the uncorrelated case of the Anderson limit in low temperatures, which indicates that the off-diagonal correlations in DNA sequences have a great effect on the AC conductivity, while at high temperature the off-diagonal correlations no longer play a vital role in electric transport. In addition, the proportion of nucleotide pairs p also plays an important role in AC electron transport of DNA sequences. For p < 0.5, the conductivity of DNA sequence decreases with the increase of p, while for p ≥ 0.5, the conductivity increases with the increase of p. (cross-disciplinary physics and related areas of science and technology)

  10. Characteristics of alternating current hopping conductivity in DNA sequences

    Institute of Scientific and Technical Information of China (English)

    Ma Song-Shan; Xu Hui; Wang Huan-You; Guo Rui

    2009-01-01

    This paper presents a model to describe alternating current (AC) conductivity of DNA sequences,in which DNA is considered as a one-dimensional (1D) disordered system,and electrons transport via hopping between localized states.It finds that AC conductivity in DNA sequences increases as the frequency of the external electric field rises,and it takes the form of σac(ω)~ω2 ln2(1/ω).Also AC conductivity of DNA sequences increases with the increase of temperature,this phenomenon presents characteristics of weak temperature-dependence.Meanwhile,the AC conductivity in an off diagonally correlated case is much larger than that in the uncorrelated case of the Anderson limit in low temperatures,which indicates that the off-diagonal correlations in DNA sequences have a great effect on the AC conductivity,while at high temperature the off-diagonal correlations no longer play a vital role in electric transport. In addition,the proportion of nucleotide pairs p also plays an important role in AC electron transport of DNA sequences.For p<0.5,the conductivity of DNA sequence decreases with the increase of p,while for p > 0.5,the conductivity increases with the increase of p.

  11. ALTERNATIVE MICROBIAL INDICATORS OF FAECAL POLLUTION: CURRENT PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    V. K. Tyagi, A. K. Chopra, A. A. Kazmi, Arvind Kumar

    2006-07-01

    Full Text Available Worldwide coliform bacteria are used as indicators of fecal contamination and hence, the possible presence of disease causing organisms. Therefore, it is important to understand the potential and limitations of these indicator organisms before realistically implementing guidelines and regulations to safeguard our water resources and public health. This review addresses the limitations of current faecal indicator microorganisms and proposed significant alternative microbial indicators of water and wastewater quality. The relevant literature brings out four such significant microbial water pollution indicators and the study of these indicators will reveal the total spectrum of water borne pathogens. As E.coli and enterococci indicates the presence of bacterial pathogens, Coliphages indicate the presence of enteric viruses, and Clostridium perfringens, an obligate anaerobe, indicates presence of parasitic protozoan and enteric viruses. Therefore, monitoring a suite of indicator organisms in reclaimed effluent is more likely to be predictive of the presence of certain pathogens in order to protect public health, as no single indicator is most highly predictive of membership in the presence or absence category for pathogens.

  12. Alternate transmission with half-duplex relaying in MIMO interference relay networks

    KAUST Repository

    Park, Seongho

    2013-12-01

    In this paper, we consider an alternate transmission scheme for a multiple-input multiple-output interference relay channel where multiple sources transmit their own signals to their corresponding destinations via one of two relaying groups alternately every time phase. Each of the relaying groups has arbitrary number of relays, and each relay operates in half-duplex amplify-and-forward mode. In our scheme, the received signals at the relay nodes consist of desired signals and two different interference signals such as the inter-source interferences and the inter-group interferences which are caused by the phase incoherence of relaying. As such, we propose an iterative interference alignment algorithm to mitigate the interferences. We show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying system in the interference relay channels. © 2013 IEEE.

  13. Precision electronic speed controller for an alternating-current motor

    Science.gov (United States)

    Bolie, V.W.

    A high precision controller for an alternating-current multi-phase electrical motor that is subject to a large inertial load. The controller was developed for controlling, in a neutron chopper system, a heavy spinning rotor that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal having a meandering line frequency. The controller includes a shaft revolution sensor which provides a feedback pulse train representative of the actual speed of the motor. An internal digital timing signal generator provides a reference signal which is compared with the feedback signal in a computing unit to provide a motor control signal. The motor control signal is a weighted linear sum of a speed error voltage, a phase error voltage, and a drift error voltage, each of which is computed anew with each revolution of the motor shaft. The speed error signal is generated by a novel vernier-logic circuit which is drift-free and highly sensitive to small speed changes. The phase error is also computed by digital logic, with adjustable sensitivity around a 0 mid-scale value. The drift error signal, generated by long-term counting of the phase error, is used to compensate for any slow changes in the average friction drag on the motor. An auxillary drift-byte status sensor prevents any disruptive overflow or underflow of the drift-error counter. An adjustable clocked-delay unit is inserted between the controller and the source of the reference pulse train to permit phase alignment of the rotor to any desired offset angle. The stator windings of the motor are driven by two amplifiers which are provided with input signals having the proper quadrature relationship by an exciter unit consisting of a voltage controlled oscillator, a binary counter, a pair of read-only memories, and a pair of digital-to-analog converters.

  14. Alternating-current transport losses of melt-cast processed Bi-2212 bulk superconductor bars

    International Nuclear Information System (INIS)

    Tsukamoto, T; Inada, R; Inagaki, N; Andoh, H; Sugiura, T; Oota, A

    2003-01-01

    Using a melt-casting method, we have fabricated two pieces of Bi-2212 bulk superconductor bar with square and rectangular cross-sections, and we have investigated the alternating-current (ac) transport self-field losses at 77 K. Despite the main contribution of hysteresis loss of the superconductor, there is some difference in the loss behaviour between these two samples. To elucidate the origin, we make numerical calculations on the ac transport self-field losses as a function of current amplitude I 0 below the critical current I c . At a fixed I 0 , the calculated values using the uniform J c distribution and the actual cross-sectional geometry are much higher than the experimental data for the sample with a square cross-section 7.5 x 7.5 mm 2 , while there is good agreement between the calculation and the experiment for the sample with a rectangular cross-section 4.5 x 13.6 mm 2 . The discrepancy appearing in the sample with a square cross-section is ascribed to the actual J c distribution, which is confirmed by critical current measurements when scraping off the sample. The local J c value decreases significantly in going from the surface to the interior of the sample. This suppresses the extension of the flux-penetration region to the interior under ac current transmission and lowers the loss generation compared with the calculated results obtained by the uniform J c distribution

  15. Alternate current interference in pipeline; Interferencia por corrente alternada em dutos

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, Joao Hipolito de Lima [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2003-07-01

    This paper regards to the concerning that the pipeline operators should take in to account to better understand and control the alternate current interference (AC- interference). Pipelines sharing rights-of-way with AC high voltage power lines are subjected to AC interference that can cause risk for personnel, operational safety and environment. The AC-interference shall be evaluated, in such way that mitigating action can be applied in order to assure the pipeline is operated in a safety way. The AC-interference evaluation should take in to account the pipeline and the electrical generation/transmission design data. Three approaches are considered: the coating integrity, the personnel chock hazards and the pipeline integrity. The coating integrity is affected by the possibility of high-voltage be induced on the pipeline during power line current fault. The operation and maintenance personnel can be prone to chock hazards (touch voltage and step voltage), depending upon the level of the induced voltage on the pipeline and the ground current. An induced voltage evaluation is then necessary to identify AC potentials in pipeline higher than the safe criteria. The pipeline integrity is concerning to the possibility of occurring alternate current corrosion (AC-corrosion) on the pipe wall. This kind of corrosion is still been investigated, and although it is less critical than the direct current corrosion, it can happen in specific situation. Parameters that affect AC-corrosion are discussed in this paper. Finely it is presented a brief guide to evaluate the possibility of occurring AC- interference in a pipeline and a mitigation measures summary. (author)

  16. Current Status of Helium-3 Alternative Technologies for Nuclear Safeguards

    International Nuclear Information System (INIS)

    Henzlova, Daniela; Kouzes, R.; McElroy, R.; Peerani, P.; Baird, K.; Bakel, A.; Borella, M.; Bourne, M.; Bourva, L.; Cave, F.; Chandra, R.; Chernikova, D.; Croft, S.; Dermody, G.; Dougan, A.; Ely, J.; Fanchini, E.; Finocchiaro, P.; Gavron, Victor; Kureta, M.; Ianakiev, Kiril Dimitrov; Ishiyama, K.; Lee, T.; Martin, Ch.; McKinny, K.; Menlove, Howard Olsen; Orton, Ch.; Pappalardo, A.; Pedersen, B.; Plenteda, R.; Pozzi, S.; Schear, M.; Seya, M.; Siciliano, E.; Stave, S.; Sun, L.; Swinhoe, Martyn Thomas; Tagziria, H.; Takamine, J.; Weber, A.-L.; Yamaguchi, T.; Zhu, H.

    2015-01-01

    International safeguards inspectorates (e.g., International Atomic Energy Agency, or Euratom) rely heavily on neutron assay techniques, and in particular, on coincidence counters for the verification of declared nuclear materials under safeguards and for monitoring purposes. While 3 He was readily available, the reliability, safety, ease of use, gamma-ray insensitivity, and high intrinsic thermal neutron detection efficiency of 3 He-based detectors obviated the need for alternative detector technologies. However, the recent decline of the 3 He gas supply has triggered international efforts to develop and field neutron detectors that make use of alternative materials. In response to this global effort, the U.S. Department of Energy's (DOE) National Nuclear Security Administration (NNSA) and Euratom launched a joint effort aimed at bringing together international experts, technology users and developers in the field of nuclear safeguards to discuss and evaluate the proposed 3 He alternative materials and technologies. The effort involved a series of two workshops focused on detailed overviews and viability assessments of various 3 He alternative technologies for use in nuclear safeguards applications. The key objective was to provide a platform for collaborative discussions and technical presentations organized in a compact, workshop-like format to stimulate interactions among the participants. The meetings culminated in a benchmark exercise providing a unique opportunity for the first inter-comparison of several available alternative technologies. This report provides an overview of the alternative technology efforts presented during the two workshops along with a summary of the benchmarking activities and results. The workshop recommendations and key consensus observations are discussed in the report, and used to outline a proposed path forward and future needs foreseeable in the area of 3 He-alternative technologies.

  17. Current Status of Helium-3 Alternative Technologies for Nuclear Safeguards

    Energy Technology Data Exchange (ETDEWEB)

    Henzlova, Daniela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kouzes, R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McElroy, R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Peerani, P. [European Commission, Ispra (Italy). Joint Research Centre; Aspinall, M. [Hybrid Instruments Ltd., Birmingham (United Kingdom); Baird, K. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Bakel, A. [National Nuclear Security Administration (NNSA), Washington, DC (United States); Borella, M. [SCK.CEN, Mol (Belgium); Bourne, M. [Univ. of Michigan, Ann Arbor, MI (United States); Bourva, L. [Canberra Ltd., Oxford (United Kingdom); Cave, F. [Hybrid Instruments Ltd., Birmingham (United Kingdom); Chandra, R. [Arktis Radiation Detectors Ltd., Zurich (Sweden); Chernikova, D. [Chalmers Univ. of Technology (Sweden); Croft, S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dermody, G. [Symetrica Inc., Maynard, MA (United States); Dougan, A. [National Nuclear Security Administration (NNSA), Washington, DC (United States); Ely, J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fanchini, E. [Istituto Nazionale di Fisica Nucleare (INFN), Milano (Italy); Finocchiaro, P. [Istituto Nazionale di Fisica Nucleare (INFN), Milano (Italy); Gavron, Victor [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Kureta, M. [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Ianakiev, Kiril Dimitrov [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Ishiyama, K. [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Lee, T. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Martin, Ch. [Symetrica Inc., Maynard, MA (United States); McKinny, K. [GE Reuter-Stokes, Twinsburg, OH (United States); Menlove, Howard Olsen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Orton, Ch. [National Nuclear Security Administration (NNSA), Washington, DC (United States); Pappalardo, A. [Istituto Nazionale di Fisica Nucleare (INFN), Milano (Italy); Pedersen, B. [European Commission, Ispra (Italy). Joint Research Centre; Peranteau, D. [National Nuclear Security Administration (NNSA), Washington, DC (United States); Plenteda, R. [Intl Atomic Energy Agency (IAEA), Vienna (Austria); Pozzi, S. [Univ. of Michigan, Ann Arbor, MI (United States); Schear, M. [Symetrica Inc., Maynard, MA (United States); Seya, M. [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Siciliano, E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stave, S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sun, L. [Proportional Technologies Inc., Houston, TX (United States); Swinhoe, Martyn Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tagziria, H. [European Commission, Ispra (Italy). Joint Research Centre; Vaccaro, S. [DG Energy (Luxembourg); Takamine, J. [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Weber, A. -L. [Inst. for Radiological Protection and Nuclear Safety (IRSN), Fontenay-aux-Roses (France); Yamaguchi, T. [Japan Atomic Energy Agency (JAEA), Tokai (Japan); Zhu, H. [National Nuclear Security Administration (NNSA), Washington, DC (United States)

    2015-12-01

    International safeguards inspectorates (e.g., International Atomic Energy Agency {IAEA}, or Euratom) rely heavily on neutron assay techniques, and in particular, on coincidence counters for the verification of declared nuclear materials under safeguards and for monitoring purposes. While 3He was readily available, the reliability, safety, ease of use, gamma-ray insensitivity, and high intrinsic thermal neutron detection efficiency of 3He-based detectors obviated the need for alternative detector technologies. However, the recent decline of the 3He gas supply has triggered international efforts to develop and field neutron detectors that make use of alternative materials. In response to this global effort, the U.S. Department of Energy’s (DOE) National Nuclear Security Administration (NNSA) and Euratom launched a joint effort aimed at bringing together international experts, technology users and developers in the field of nuclear safeguards to discuss and evaluate the proposed 3He alternative materials and technologies. The effort involved a series of two workshops focused on detailed overviews and viability assessments of various 3He alternative technologies for use in nuclear safeguards applications. The key objective was to provide a platform for collaborative discussions and technical presentations organized in a compact, workshop-like format to stimulate interactions among the participants. The meetings culminated in a benchmark exercise providing a unique opportunity for the first inter-comparison of several available alternative technologies. This report provides an overview of the alternative technology efforts presented during the two workshops along with a summary of the benchmarking activities and results. The workshop recommendations and key consensus observations are discussed in the report, and used to outline a proposed path forward and future needs foreseeable in the area of 3He-alternative

  18. Proposal and Development of a High Voltage Variable Frequency Alternating Current Power System for Hybrid Electric Aircraft

    Science.gov (United States)

    Sadey, David J.; Taylor, Linda M.; Beach, Raymond F.

    2017-01-01

    The development of ultra-efficient commercial vehicles and the transition to low-carbon emission propulsion are seen as strategic thrust paths within NASA Aeronautics. A critical enabler to these paths comes in the form of hybrid electric propulsion systems. For megawatt-class systems, the best power system topology for these hybrid electric propulsion systems is debatable. Current proposals within NASA and the Aero community suggest using a combination of alternating current (AC) and direct current (DC) for power generation, transmission, and distribution. This paper proposes an alternative to the current thought model through the use of a primarily high voltage AC power system, supported by the Convergent Aeronautics Solutions (CAS) Project. This system relies heavily on the use of doubly-fed induction machines (DFIMs), which provide high power densities, minimal power conversion, and variable speed operation. The paper presents background on the activity along with the system architecture, development status, and preliminary results.

  19. Interactions Between Indirect DC-Voltage Estimation and Circulating Current Controllers of MMC-Based HVDC Transmission Systems

    DEFF Research Database (Denmark)

    Wickramasinghe, Harith R.; Konstantinou, Georgios; Pou, Josep

    2018-01-01

    Estimation-based indirect dc-voltage control in MMCs interacts with circulating current control methods. This paper proposes an estimation-based indirect dc-voltage control method for MMC-HVDC systems and analyzes its performance compared to alternative estimations. The interactions between......-state and transient performance is demonstrated using a benchmark MMC-HVDC transmission system, implemented in a real-time digital simulator. The results verify the theoretical evaluations and illustrate the operation and performance of the proposed indirect dc-voltage control method....

  20. Innovations in electrophoretic deposition: Alternating current and pulsed direct current methods

    International Nuclear Information System (INIS)

    Chávez-Valdez, Alejandra; Boccaccini, Aldo R.

    2012-01-01

    This review summarizes emerging developments in the field of alternating current (AC) and pulsed direct current (DC) electrophoretic deposition (EPD) in aqueous or organic media. Numerous applications of AC-EPD are discussed including two major groups of investigations: (i) AC-EPD to suppress water hydrolysis at high voltages in inorganic (ceramic) coatings and (ii) AC-EPD for deposition of biological entities. The deposition, purification and manipulation of carbon nanotubes and nanoparticles by AC-EPD to form specific arrays, for development of sensors and other electronic devices and the application of AC-EPD as method for separation of particles according to their shape or size are also presented. Other applications reviewed relate to the fabrication by AC-EPD of toxic gas sensors from oxides and superconducting layers. The main materials being examined by AC-EPD are inorganic, including carbon nanotubes, TiO 2 nanoparticles, Al 2 O 3 , Si, SnO 2 , ZnO and WO 3 and biological entities, e.g. bacteria cells. For pulsed EPD, the applications reviewed are divided in pulsed current and pulsed voltage EPD. Among the applications of pulsed EPD, the formation of thick films from aqueous suspensions without water decomposition, the fabrication of multilayer and composite materials and the size-selective deposition of ceramic nanoparticles are the most important investigated to date, based on the quality of the coatings and deposits obtained and their relevance for applications.

  1. A Comparison of Alternating Current and Direct Current Electrospray Ionization for Mass Spectrometry

    Science.gov (United States)

    Sarver, Scott A.; Chetwani, Nishant; Dovichi, Norman J.; Go, David B.; Gartner, Carlos A.

    2014-04-01

    A series of studies comparing the performance of alternating current electrospray ionization (AC ESI) mass spectrometry (MS) and direct current electrospray ionization (DC ESI) MS have been conducted, exploring the absolute signal intensity and signal-to-background ratios produced by both methods using caffeine and a model peptide as targets. Because the high-voltage AC signal was more susceptible to generating gas discharges, the operating voltage range of AC ESI was significantly smaller than that for DC ESI, such that the absolute signal intensities produced by DC ESI at peak voltages were one to two orders of magnitude greater than those for AC ESI. Using an electronegative nebulizing gas, sulfur hexafluoride (SF6), instead of nitrogen (N2) increased the operating range of AC ESI by ~50 %, but did not appreciably improve signal intensities. While DC ESI generated far greater signal intensities, both ionization methods produced comparable signal-to-background noise, with AC ESI spectra appearing qualitatively cleaner. A quantitative calibration analysis was performed for two analytes, caffeine and the peptide MRFA. AC ESI utilizing SF6 outperforms all other techniques for the detection of MRFA, producing chromatographic limits of detection nearly one order of magnitude lower than that of DC ESI utilizing N2, and one-half that of DC ESI utilizing SF6. However, DC ESI outperforms AC ESI for the analysis of caffeine, indicating that improvements in spectral quality may benefit certain compounds or classes of compounds, on an individual basis.

  2. Alternating-Current Motor Drive for Electric Vehicles

    Science.gov (United States)

    Krauthamer, S.; Rippel, W. E.

    1982-01-01

    New electric drive controls speed of a polyphase as motor by varying frequency of inverter output. Closed-loop current-sensing circuit automatically adjusts frequency of voltage-controlled oscillator that controls inverter frequency, to limit starting and accelerating surges. Efficient inverter and ac motor would give electric vehicles extra miles per battery charge.

  3. Electrical Power Supply to Offshore Oil Installations by High Voltage Direct Current Transmission

    Energy Technology Data Exchange (ETDEWEB)

    Myhre, Joergen Chr.

    2001-07-01

    This study was initiated to investigate if it could be feasible to supply offshore oil installations in the North Sea with electrical power from land. A prestudy of alternative converter topologies indicated that the most promising solution would be to investigate a conventional system with reduced synchronous compensator rating. The study starts with a summary of the state of power supply to offshore installations today, and a short review of classical HVDC transmission. It goes on to analyse how a passive network without sources influences the inverter. The transmission, with its current controlled rectifier and large inductance, is simulated as a current source. Under these circumstances the analysis shows that the network frequency has to adapt in order to keep the active and reactive power balance until the controllers are able to react. The concept of firing angle for a thyristor is limited in a system with variable frequency, the actual control parameter is the firing delay time. Sensitivity analysis showed some astonishing consequences. The frequency rises both by an increase in the active and in the reactive load. The voltage falls by an increase in the active load, but rises by an increase in the inductive load. Two different control principles for the system of inverter, synchronous compensator and load are defined. The first takes the reference for the firing delay time from the fundamental voltage at the point of common coupling. The second takes the reference for the firing delay time from the simulated EMF of the synchronous compensator. Of these, the second is the more stable and should be chosen as the basis for a possible control system. Two simulation tools are applied. The first is a quasi-phasor model running on Matlab with Simulink. The other is a time domain model in KREAN. The time domain model is primarily used for the verification of the quasi-phasor model, and shows that quasi-phasors is still a valuable tool for making a quick analysis

  4. Alternating-current MHD conduction pump for ferrous metals

    International Nuclear Information System (INIS)

    Nadezhnikov, N.M.; Krauya, V.M.; Yankop, E.K.

    1979-01-01

    Results are presented of theoretical and experimental studies pertaining to an ac MHD conduction pump with separate excitation and a C-core magnet structure. Its mathematical model is based on the following assumptions: (1) During complete braking the liquid metal in the channel is stationary; (2) there is no current leakage in the channel beyond the interelectrode region; (3) during operation the longitudinal axis of the pump is in a vertical position; (4) the current density in the electrodes at a distance infinitely far from the active channel segment is uniformly distributed; (5) there are no magnetic leakage fluxes in the model; and (6) the left-hand electrode in the model can be brought out in two different ways, variant I or variant II. 7 references

  5. Current status and future directions for in situ transmission electron microscopy

    DEFF Research Database (Denmark)

    Taheri, Mitra L.; Stach, Eric A.; Arslan, Ilke

    2016-01-01

    This review article discusses the current and future possibilities for the application of in situ transmission electron microscopy to reveal synthesis pathways and functional mechanisms in complex and nanoscale materials. The findings of a group of scientists, representing academia, government labs...

  6. Alternative forms of energy transmission from OTEC plants. [Chemical and electrical

    Energy Technology Data Exchange (ETDEWEB)

    Konopka, A.; Biederman, N.; Talib, A.; Yudow, B.

    1977-01-01

    The transmission of OTEC-derived chemical and electrical energy is compared. The chemical energy-carriers considered are the following: gaseous and liquid hydrogen, liquid ammonia, methanol, gasoline, hydrazine hydrate, anhydrous hydrazine, unsymmetrical dimethylhydrazine (UDMH), 1,7-Octadiyne, and tetrahydrodicyclopentadiene. The assessment assumes that each of the above energy carriers were transported by barge and/or pipeline. The delivered costs were then compared with transmission of electricity by submarine cables. Because chemical and electrical energy are not equivalent, however, their comparison can only be done after the outputs are converted to a common form. Thus, in addition to presenting the delivered cost and overall energy efficiency of the chemical energy-carriers, we have provided a discussion of the equipment, costs, and efficiencies of converting the hydrogen and ammonia delivered into electricity, and the electricity delivered into hydrogen and ammonia. A concise technical assessment and economic analysis of components associated with the conversion, storage, transportation, and shore-based receiving facilities for the conversion of OTEC mechanical energy to chemical energy is provided and compared to the conversion and transmission of electrical power. Results concerning the hydrogen and ammonia analysis were determined as part of the OTEC program at IGT from May 1975 through May 1976 under Contract No. NSF-C1008 (AER-75-00033) with the National Science Foundation and ERDA. Information concerning carbonaceous fuels and high-energy fuels production was developed as part of the current IGT OTEC program under Contract No. E(49-18)-2426 with ERDA.

  7. Experiments on toroidal inductively coupled alternating-current gas discharges

    International Nuclear Information System (INIS)

    Lok, J.

    1976-01-01

    This report is on an experimental study of a toroidal, inductively coupled a.c. gas discharge sustained at pressures roughly between one tenth of a Torr and some tens of Torrs. After breakdown is obtained at low pressure, additional gas is let in. The energy is inductively coupled into the electrodeless discharge by means of an iron core transformer of which the toroidal plasma column is the secondary winding. The power dissipated in the plasma is between 80 and 260 kW and is delivered by a motor-generator system at a frequency of 8 kHz for times up to 2 seconds. A toroidal magnetic field of 0.5 T maximum can be supplied in a short pulse. Five different gases (hydrogen, deuterium, helium, argon, and nitrogen) are used. The pressure range in which the discharges are sustained is specified, and the dynamic current-voltage characteristics are given for different pressures. Some typical streak pictures with simultaneously obtained recordings of the time behaviour of the discharge current and of the loop voltage are presented for the initial phase - at low pressure - of the discharge. The shape and the position of fully developed discharges at various pressures are discussed on the basis of photographic observations. The temperature of hydrogen plasmas is derived both from the electrical conductivity and from the emission of line radiation. The values of the temperature obtained in these ways differ in magnitude and in time behaviour. A possible explanation of the discrepancy can be obtained in terms of expansion and contraction of electron density and temperature profiles during a period of the discharge current, if it is taken into account that the main part of the light emission always originates from the outer colder regions of the plasma. In a somewhat different pressure regime, this picture is confirmed by microwave measurements

  8. Study of criterion for assuring the effectiveness of cathodic protection of buried steel pipelines being interfered with alternative current

    Energy Technology Data Exchange (ETDEWEB)

    He, X.; Jiang, G.; Qiu, Y.; Tang, H. [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan (China); Zhang, G.; Jin, X.; Xiang, Z. [Huazhong Natural Gas Subsidiary of PetroChina Pipeline Company, Wuhan (China); Zhang, Z. [Dwell Company Limited, PetroChina Engineering Company, Ltd, Beijing (China)

    2012-06-15

    Interference of alternative current (AC) on corrosion of X65 steel was investigated in soil. It was observed that the unfavorable effect of interfering AC was able to be effectively inhibited by increasing the direct current density of the cathodic protection (CP) system. A clear correlation was established between the CP current density and the tolerable AC current density. This led to a new criterion for assuring the effectiveness of CP of buried pipelines being interfered with AC. Field experimental results on a buried pipeline running below a 500 kV transmission line showed that the criterion could satisfactorily predict the risk of AC interfering on the CP system. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Bipole III transmission line Henday-Riel: Alternative corridors status report

    International Nuclear Information System (INIS)

    1991-01-01

    As part of expansion plans in the Manitoba Hydro system, it is proposed to build a 850-km high voltage dc transmission line from the Henday converter station on the Nelson River to a new converter station near Winnipeg. A review is provided of work done on the first stage of route selection and environmental assessment for this project. Right-of-way requirements are outlined and environmental impact issues are discussed in the areas of employment and business opportunities, effects on wilderness areas and aesthetics, electric and magnetic field effects, and land use. The four zones, east and west of Lake Winnipeg, that were studied in the selection of potential corridors are described along with the corridor siting criteria. Five discrete corridor alternatives are identified and evaluated. A route east of Lake Winnipeg has been selected as the preferred corridor. Feedback from public consultations will assist in preparation of a final corridor selection study which is to be submitted to federal and provincial environmental review. 12 figs

  10. Current status and future directions for in situ transmission electron microscopy

    International Nuclear Information System (INIS)

    Taheri, Mitra L.; Stach, Eric A.; Arslan, Ilke; Crozier, P.A.; Kabius, Bernd C.; LaGrange, Thomas; Minor, Andrew M.; Takeda, Seiji; Tanase, Mihaela; Wagner, Jakob B.; Sharma, Renu

    2016-01-01

    This review article discusses the current and future possibilities for the application of in situ transmission electron microscopy to reveal synthesis pathways and functional mechanisms in complex and nanoscale materials. The findings of a group of scientists, representing academia, government labs and private sector entities (predominantly commercial vendors) during a workshop, held at the Center for Nanoscale Science and Technology- National Institute of Science and Technology (CNST-NIST), are discussed. We provide a comprehensive review of the scientific needs and future instrument and technique developments required to meet them. - Highlights: • Evaluation of currently available technology for performing in situ experiments using transmission electron microscope. • Limitations of currently available instrumentation with respect to base TEM, specialty TEM holders, and data acquisition systems. • Guidelines and wish list for the areas of future development.

  11. Current status and future directions for in situ transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, Mitra L. [Department of Materials Science and Engineering, Drexel University (United States); Stach, Eric A. [Center for Functional Nanomaterials, National Laboratory, Brookhaven (United States); Arslan, Ilke [Pacific Northwest National Laboratory, Physical and Computational Sciences Directorate, 902 Battelle Blvd, Richland, WA (United States); Crozier, P.A. [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85281 (United States); Kabius, Bernd C. [The Pennsylvania State University, University Park, PA 16802 (United States); LaGrange, Thomas [Lawrence Livermore National Laboratory, Physical and Life Science Directorate, Condensed Matter and Materials Division, 7000 East Avenue, P.O. 808 L-356 (United States); Minor, Andrew M. [Department of Materials Science & Engineering, University of California, Berkeley and National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, One Cyclotron Road, MS 72, Berkeley, CA (United States); Takeda, Seiji [Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Tanase, Mihaela [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899-6203 (United States); Wagner, Jakob B. [Center for Electron Nanoscopy, Technical University of Denmark, Kgs, Lyngby (Denmark); Sharma, Renu, E-mail: renu.sharma@nist.gov [Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899-6203 (United States)

    2016-11-15

    This review article discusses the current and future possibilities for the application of in situ transmission electron microscopy to reveal synthesis pathways and functional mechanisms in complex and nanoscale materials. The findings of a group of scientists, representing academia, government labs and private sector entities (predominantly commercial vendors) during a workshop, held at the Center for Nanoscale Science and Technology- National Institute of Science and Technology (CNST-NIST), are discussed. We provide a comprehensive review of the scientific needs and future instrument and technique developments required to meet them. - Highlights: • Evaluation of currently available technology for performing in situ experiments using transmission electron microscope. • Limitations of currently available instrumentation with respect to base TEM, specialty TEM holders, and data acquisition systems. • Guidelines and wish list for the areas of future development.

  12. Current and future alternative therapies for beta-thalassemia major

    Directory of Open Access Journals (Sweden)

    Edouard de Dreuzy

    2016-02-01

    Full Text Available Beta-thalassemia is a group of frequent genetic disorders resulting in the synthesis of little or no β-globin chains. Novel approaches are being developed to correct the resulting α/β-globin chain imbalance, in an effort to move beyond the palliative management of this disease and the complications of its treatment (e.g. life-long red blood cell transfusion, iron chelation, splenectomy, which impose high costs on healthcare systems. Three approaches are envisaged: fetal globin gene reactivation by pharmacological compounds injected into patients throughout their lives, allogeneic hematopoietic stem cell transplantation (HSCT, and gene therapy. HSCT is currently the only treatment shown to provide an effective, definitive cure for β-thalassemia. However, this procedure remains risky and histocompatible donors are identified for only a small fraction of patients. New pharmacological compounds are being tested, but none has yet made it into common clinical practice for the treatment of beta-thalassemia major. Gene therapy is in the experimental phase. It is emerging as a powerful approach without the immunological complications of HSCT, but with other possible drawbacks. Rapid progress is being made in this field, and long-term efficacy and safety studies are underway.

  13. Transmission line component testing for the ITER Ion Cyclotron Heating and Current Drive System

    Science.gov (United States)

    Goulding, Richard; Bell, G. L.; Deibele, C. E.; McCarthy, M. P.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Barbier, C. N.; Cambell, I. H.; Moon, R. L.; Pesavento, P. V.; Fredd, E.; Greenough, N.; Kung, C.

    2014-10-01

    High power RF testing is underway to evaluate transmission line components for the ITER Ion Cyclotron Heating and Current Drive System. The transmission line has a characteristic impedance Z0 = 50 Ω and a nominal outer diameter of 305 mm. It is specified to carry up to 6 MW at VSWR = 1.5 for 3600 s pulses, with transient voltages up to 40 kV. The transmission line is actively cooled, with turbulent gas flow (N2) used to transfer heat from the inner to outer conductor, which is water cooled. High voltage and high current testing of components has been performed using resonant lines generating steady state voltages of 35 kV and transient voltages up to 60 kV. A resonant ring, which has operated with circulating power of 6 MW for 1 hr pulses, is being used to test high power, low VSWR operation. Components tested to date include gas barriers, straight sections of various lengths, and 90 degree elbows. Designs tested include gas barriers fabricated from quartz and aluminum nitride, and transmission lines with quartz and alumina inner conductor supports. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

  14. Research on the correlation between corona current spectrum and audible noise spectrum of HVDC transmission line

    Science.gov (United States)

    Liu, Yingyi; Zhou, Lijuan; Liu, Yuanqing; Yuan, Haiwen; Ji, Liang

    2017-11-01

    Audible noise is closely related to corona current on a high voltage direct current (HVDC) transmission line. In this paper, we measured a large amount of audible noise and corona current waveforms simultaneously based on the largest outdoor HVDC corona cage all over the world. By analyzing the experimental data, the related statistical regularities between a corona current spectrum and an audible noise spectrum were obtained. Furthermore, the generation mechanism of audible noise was analyzed theoretically, and the related mathematical expression between the audible noise spectrum and the corona current spectrum, which is suitable for all of these measuring points in the space, has been established based on the electro-acoustic conversion theory. Finally, combined with the obtained mathematical relation, the internal reasons for these statistical regularities appearing in measured corona current and audible noise data were explained. The results of this paper not only present the statistical association regularities between the corona current spectrum and the audible noise spectrum on a HVDC transmission line, but also reveal the inherent reasons of these associated rules.

  15. Release of lungworm larvae from snails in the environment: potential for alternative transmission pathways.

    Directory of Open Access Journals (Sweden)

    Alessio Giannelli

    2015-04-01

    Full Text Available Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis. In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host.Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior. Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior.Results of this study

  16. DC bias effect on alternating current electrical conductivity of poly(ethylene terephthalate)/alumina nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Nikam, Pravin N., E-mail: pravinya26@gmail.com; Deshpande, Vineeta D., E-mail: drdeshpandevd@gmail.com [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai-400019, Maharashtra (India)

    2016-05-06

    Polymer nanocomposites based on metal oxide (ceramic) nanoparticles are a new class of materials with unique properties and designed for various applications such as electronic device packaging, insulation, fabrication and automotive industries. Poly(ethylene terephthalate) (PET)/alumina (Al{sub 2}O{sub 3}) nanocomposites with filler content between 1 wt% and 5 wt% were prepared by melt compounding method using co-rotating twin screw extruder and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and precision LCR meter techniques. The results revealed that proper uniform dispersion at lower content up to 2 wt% of nano-alumina observed by using TEM. Aggregation of nanoparticles was observed at higher content of alumina examined by using SEM and TEM. The frequency dependences of the alternating current (AC) conductivity (σ{sub AC}) of PET/alumina nanocomposites on the filler content and DC bias were investigated in the frequency range of 20Hz - 1MHz. The results showed that the AC and direct current (DC) conductivity increases with increasing DC bias and nano-alumina content upto 3 wt%. It follows the Jonscher’s universal power law of solids. It revealed that σ{sub AC} of PET/alumina nanocomposites can be well characterized by the DC conductivity (σ{sub DC}), critical frequency (ω{sub c}), critical exponent of the power law (s). Roll of DC bias potential led to an increase of DC conductivity (σ{sub DC}) due to the creation of additional conducting paths with the polymer nanocomposites and percolation behavior achieved through co-continuous morphology.

  17. DC bias effect on alternating current electrical conductivity of poly(ethylene terephthalate)/alumina nanocomposites

    Science.gov (United States)

    Nikam, Pravin N.; Deshpande, Vineeta D.

    2016-05-01

    Polymer nanocomposites based on metal oxide (ceramic) nanoparticles are a new class of materials with unique properties and designed for various applications such as electronic device packaging, insulation, fabrication and automotive industries. Poly(ethylene terephthalate) (PET)/alumina (Al2O3) nanocomposites with filler content between 1 wt% and 5 wt% were prepared by melt compounding method using co-rotating twin screw extruder and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and precision LCR meter techniques. The results revealed that proper uniform dispersion at lower content up to 2 wt% of nano-alumina observed by using TEM. Aggregation of nanoparticles was observed at higher content of alumina examined by using SEM and TEM. The frequency dependences of the alternating current (AC) conductivity (σAC) of PET/alumina nanocomposites on the filler content and DC bias were investigated in the frequency range of 20Hz - 1MHz. The results showed that the AC and direct current (DC) conductivity increases with increasing DC bias and nano-alumina content upto 3 wt%. It follows the Jonscher's universal power law of solids. It revealed that σAC of PET/alumina nanocomposites can be well characterized by the DC conductivity (σDC), critical frequency (ωc), critical exponent of the power law (s). Roll of DC bias potential led to an increase of DC conductivity (σDC) due to the creation of additional conducting paths with the polymer nanocomposites and percolation behavior achieved through co-continuous morphology.

  18. DC bias effect on alternating current electrical conductivity of poly(ethylene terephthalate)/alumina nanocomposites

    International Nuclear Information System (INIS)

    Nikam, Pravin N.; Deshpande, Vineeta D.

    2016-01-01

    Polymer nanocomposites based on metal oxide (ceramic) nanoparticles are a new class of materials with unique properties and designed for various applications such as electronic device packaging, insulation, fabrication and automotive industries. Poly(ethylene terephthalate) (PET)/alumina (Al_2O_3) nanocomposites with filler content between 1 wt% and 5 wt% were prepared by melt compounding method using co-rotating twin screw extruder and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and precision LCR meter techniques. The results revealed that proper uniform dispersion at lower content up to 2 wt% of nano-alumina observed by using TEM. Aggregation of nanoparticles was observed at higher content of alumina examined by using SEM and TEM. The frequency dependences of the alternating current (AC) conductivity (σ_A_C) of PET/alumina nanocomposites on the filler content and DC bias were investigated in the frequency range of 20Hz - 1MHz. The results showed that the AC and direct current (DC) conductivity increases with increasing DC bias and nano-alumina content upto 3 wt%. It follows the Jonscher’s universal power law of solids. It revealed that σ_A_C of PET/alumina nanocomposites can be well characterized by the DC conductivity (σ_D_C), critical frequency (ω_c), critical exponent of the power law (s). Roll of DC bias potential led to an increase of DC conductivity (σ_D_C) due to the creation of additional conducting paths with the polymer nanocomposites and percolation behavior achieved through co-continuous morphology.

  19. IMPROVING MODEL OF CHANNEL AIRBORN ELECTRICAL POWER SYSTEM OF ALTERNATING CURRENT

    Directory of Open Access Journals (Sweden)

    Yu. P. Artemenko

    2015-01-01

    Full Text Available This article is devoted to math modeling of channel of alternating current airborne electrical power-supply system. Mathematical modeling of generator, voltage regulator, constant speed drive is considered.

  20. High-voltage direct current (HVDC) transmission - a key technology for our power supply

    International Nuclear Information System (INIS)

    Dorn, J.

    2016-01-01

    The phasing-out of nuclear power in some countries and the aspirations of reducing carbon dioxide emissions have far-reaching implications for electric power generation in Europe. In the future, renewable electricity generation will account for a considerable share of the energy mix, but this type of production is often far from the load centers. In Germany, for example, large quantities of wind energy are already generated in the north and in the North Sea, but large load centers are located several hundred kilometers south of there. This requires an expansion of the transmission network with innovative solutions. High-voltage direct-current (HVDC) transmission plays an important role, since it brings a number of advantages over conventional AC technology and makes certain requirements feasible, for example Cable transmission over longer distances. The lecture presents the advantages of HVDC, the semiconductors used as well as the basic functions and typical performance of the used converter topopologies. The plant configurations and main components are illustrated using current projects. (rössner) [de

  1. Muscle oxygenation of vastus lateralis and medialis muscles during alternating and pulsed current electrical stimulation.

    Science.gov (United States)

    Aldayel, Abdulaziz; Muthalib, Makii; Jubeau, Marc; McGuigan, Michael; Nosaka, Kazunori

    2011-05-01

    This study compared between alternating and pulsed current electrical muscle stimulation (EMS) for muscle oxygenation and blood volume during isometric contractions. Nine healthy men (23-48 years) received alternating current EMS (2500 Hz) modulated at 75 Hz on the knee extensors of one leg, and pulsed current EMS (75 Hz) for the other leg separated by 2 weeks in a randomised, counter-balanced order. Pulse duration (400 μs), on-off ratio (5-15 s) and other stimulation parameters were matched between conditions and 30 isometric contractions were induced at the knee joint angle of 100° (0° full extension). Changes in tissue oxygenation index (∆TOI) and total hemoglobin volume (∆tHb) of vastus lateralis and medialis muscles over 30 contractions were assessed by a near-infrared spectroscopy, and were compared between conditions by a two-way repeated measures ANOVA. Peak torque produced during EMS increased over 30 contractions in response to the increase in the stimulation intensity for pulsed current, but not for the alternating current EMS. The torque during each isometric contraction was less stable in alternating than pulsed current EMS. The changes in ∆TOI amplitude during relaxation phases and ∆tHb amplitude were not significantly different between conditions. However, the decreases in ∆TOI amplitude during contraction phases from baseline were significantly (P < 0.05) greater for the pulsed current than alternating current from the 18th contraction (-15.6 ± 2.3 vs. -8.9 ± 1.8%) to 30th contraction (-10.7 ± 1.8 vs. -4.8 ± 1.5%). These results suggest that the muscles were less activated in the alternating current EMS when compared with the pulsed current EMS.

  2. Current transmission and nonlinear effects in un-gated thermionic cathode RF guns

    Energy Technology Data Exchange (ETDEWEB)

    Edelen, J. P. [Fermilab; Harris, J. R. [Air Force Weapons Lab

    2017-05-03

    Un-gated thermionic cathode RF guns are well known as a robust source of electrons for many accelerator applications. These sources are in principle scalable to high currents without degradation of the transverse emittance due to control grids but they are also known for being limited by back-bombardment. While back-bombardment presents a significant limitation, there is still a lack of general understanding on how emission over the whole RF period will affect the nature of the beams produced from these guns. In order to improve our understanding of how these guns can be used in general we develop analytical models that predict the transmission efficiency as a function of the design parameters, study how bunch compression and emission enhancement caused by Schottky barrier lowering affect the output current profile in the gun, and study the onset of space-charge limited effects and the resultant virtual cathode formation leading to a modulation in the output current distribution.

  3. Magnetic insulation regimes in high-current diodes and transmission lines of conical configuration

    International Nuclear Information System (INIS)

    Vasilenko, O.I.; Voronin, V.S.; Lebedev, A.N.

    1977-01-01

    Steady states of the electron current in a high-voltage diode and of the transmission line of conical configuration at emission current restriction by the space are considered on the basis of the self-consistant kinetic description in connection with the prospects of controlled thermonuclear synthesis. Proceeding from the magnetic self-insulation principle solved are the problems of controling the emission electron current in the double-electron geometry to prevent it from being present on the anode in the line regime and to achieve its maximum focusing in the diode regime. The motion of plasma boundaries as well as the probable contribution of the ion component of the current were not taken into consideration. It is shown that the beam focusing on the system axis takes place at sufficiently strong currents. It is connected with the fact that some part of the full diode current runs on the cathode surface. The results were compared with existing approximate diode models and with the experimetal data on focusien of strong-current beams

  4. Voltage Balancing Method on Expert System for 51-Level MMC in High Voltage Direct Current Transmission

    Directory of Open Access Journals (Sweden)

    Yong Chen

    2016-01-01

    Full Text Available The Modular Multilevel Converters (MMC have been a spotlight for the high voltage and high power transmission systems. In the VSC-HVDC (High Voltage Direct Current based on Voltage Source Converter transmission system, the energy of DC link is stored in the distributed capacitors, and the difference of capacitors in parameters and charge rates causes capacitor voltage balance which affects the safety and stability of HVDC system. A method of MMC based on the expert system for reducing the frequency of the submodules (SMs of the IGBT switching frequency is proposed. Firstly, MMC with 51 levels for HVDC is designed. Secondly, the nearest level control (NLC for 51-level MMC is introduced. Thirdly, a modified capacitor voltage balancing method based on expert system for MMC-based HVDC transmission system is proposed. Finally, a simulation platform for 51-level Modular Multilevel Converter is constructed by using MATLAB/SIMULINK. The results indicate that the strategy proposed reduces the switching frequency on the premise of keeping submodule voltage basically identical, which greatly reduces the power losses for MMC-HVDC system.

  5. Adaptive Modulation for DFIG and STATCOM With High-Voltage Direct Current Transmission.

    Science.gov (United States)

    Tang, Yufei; He, Haibo; Ni, Zhen; Wen, Jinyu; Huang, Tingwen

    2016-08-01

    This paper develops an adaptive modulation approach for power system control based on the approximate/adaptive dynamic programming method, namely, the goal representation heuristic dynamic programming (GrHDP). In particular, we focus on the fault recovery problem of a doubly fed induction generator (DFIG)-based wind farm and a static synchronous compensator (STATCOM) with high-voltage direct current (HVDC) transmission. In this design, the online GrHDP-based controller provides three adaptive supplementary control signals to the DFIG controller, STATCOM controller, and HVDC rectifier controller, respectively. The mechanism is to observe the system states and their derivatives and then provides supplementary control to the plant according to the utility function. With the GrHDP design, the controller can adaptively develop an internal goal representation signal according to the observed power system states, therefore, to achieve more effective learning and modulating. Our control approach is validated on a wind power integrated benchmark system with two areas connected by HVDC transmission lines. Compared with the classical direct HDP and proportional integral control, our GrHDP approach demonstrates the improved transient stability under system faults. Moreover, experiments under different system operating conditions with signal transmission delays are also carried out to further verify the effectiveness and robustness of the proposed approach.

  6. RF generator interlock by plasma grid bias current - An alternate to Hα interlock

    Science.gov (United States)

    Bandyopadhyay, M.; Gahlaut, A.; Yadav, R. K.; Pandya, K.; Tyagi, H.; Vupugalla, M.; Bhuyan, M.; Bhagora, J.; Chakraborty, A.

    2017-08-01

    ROBIN is inductively coupled plasma (ICP) based negative hydrogen ion source, operated with a 100kW, 1MHz Tetrode based RF generator (RFG). Inductive plasma ignition by the RFG in ROBIN is associated with electron seeding by a hot filament and a gas puff. RFG is triggered by the control system to deliver power just at the peak pressure of the gas puff. Once plasma is ignited due to proper impedance matching, a bright light, dominated by Hα (˜656nm wavelength) radiation is available inside RF driver which is used as a feedback signal to the RFG to continue its operation. If impedance matching is not correct, plasma is not produced due to lack of power coupling and bright light is not available. During such condition, reflected RF power may damage the RFG. Therefore, to protect the RFG, it needs to be switched off automatically within 200ms by the control system in such cases. This plasma light based RFG interlock is adopted from BATMAN ion source. However, in case of vacuum immersed RF ion source in reactor grade NBI system, such plasma light based interlock may not be feasible due to lack of adequate optical fiber interfaces. In reactor grade NBI system, neutron and gamma radiations have impact on materials which may lead to frequent maintenance and machine down time. The present demonstration of RFG interlock by Bias Current (BC) in ROBIN testbed gives an alternate option in this regard. In ROBIN, a bias plate (BP) is placed in the plasma chamber near the plasma grid (PG). BP is electrically connected to the plasma chamber wall of the ion source and PG is isolated from the wall. A high current ˜85 A direct current (DC) power supply of voltage in the range of 0 - 33V is connected between the PG and the BP in such a way that PG can be biased positively with respect to the BP or plasma chamber. This arrangement is actually made to absorb electrons and correspondingly reduce co-extracted electron current during beam extraction. However, in case of normal plasma

  7. Direct-current-like Phase Space Manipulation Using Chirped Alternating Current Fields

    International Nuclear Information System (INIS)

    Schmit, P.F.; Fisch, N.J.

    2010-01-01

    Waves in plasmas can accelerate particles that are resonant with the wave. A dc electric field also accelerates particles, but without a resonance discrimination, which makes the acceleration mechanism profoundly different. Whereas wave-particle acceleration mechanisms have been widely discussed in the literature, this work discusses the direct analogy between wave acceleration and dc field acceleration in a particular parameter regime explored in previous works. Apart from the academic interest of this correspondence, there may be practical advantages in using waves to mimic dc electric fields, for example, in driving plasma current with high efficiency.

  8. A robust low quiescent current power receiver for inductive power transmission in bio implants

    Science.gov (United States)

    Helalian, Hamid; Pasandi, Ghasem; Jafarabadi Ashtiani, Shahin

    2017-05-01

    In this paper, a robust low quiescent current complementary metal-oxide semiconductor (CMOS) power receiver for wireless power transmission is presented. This power receiver consists of three main parts including rectifier, switch capacitor DC-DC converter and low-dropout regulator (LDO) without output capacitor. The switch capacitor DC-DC converter has variable conversion ratios and synchronous controller that lets the DC-DC converter to switch among five different conversion ratios to prevent output voltage drop and LDO regulator efficiency reduction. For all ranges of output current (0-10 mA), the voltage regulator is compensated and is stable. Voltage regulator stabilisation does not need the off-chip capacitor. In addition, a novel adaptive biasing frequency compensation method for low dropout voltage regulator is proposed in this paper. This method provides essential minimum current for compensation and reduces the quiescent current more effectively. The power receiver was designed in a 180-nm industrial CMOS technology, and the voltage range of the input is from 0.8 to 2 V, while the voltage range of the output is from 1.2 to 1.75 V, with a maximum load current of 10 mA, the unregulated efficiency of 79.2%, and the regulated efficiency of 64.4%.

  9. A vacuum sealed high emission current and transmission efficiency carbon nanotube triode

    Energy Technology Data Exchange (ETDEWEB)

    Di, Yunsong [School of Electronic Science & Engineering, Southeast University, Nanjing 210096 (China); Jiangsu Key Laboratory of Optoelectronic Technology, Nanjing Normal University, Nanjing 210023 (China); Wang, Qilong; Zhang, Xiaobing, E-mail: bell@seu.edu.cn; Lei, Wei; Du, Xiaofei; Yu, Cairu [School of Electronic Science & Engineering, Southeast University, Nanjing 210096 (China)

    2016-04-15

    A vacuum sealed carbon nanotubes (CNTs) triode with a concave and spoke-shaped Mo grid is presented. Due to the high aperture ratio of the grid, the emission current could be modulated at a relatively high electric field. Totally 75 mA emission current has been obtained from the CNTs cathode with the average applied field by the grid shifting from 8 to 13 V/μm. Whilst with the electron transmission efficiency of the grid over 56%, a remarkable high modulated current electron beam over 42 mA has been collected by the anode. Also contributed by the high aperture ration of the grid, desorbed gas molecules could flow away from the emission area rapidly when the triode has been operated at a relative high emission current, and finally collected by a vacion pump. The working pressure has been maintained at ∼1 × 10{sup −7} Torr, seldom spark phenomena occurred. Nearly perfect I-V curve and corresponding Fowler-Nordheim (FN) plot confirmed the accuracy of the measured data, and the emission current was long term stable and reproducible. Thusly, this kind of triode would be used as a high-power electron source.

  10. 76 FR 56905 - The Central Valley Project, the California-Oregon Transmission Project, the Pacific Alternating...

    Science.gov (United States)

    2011-09-14

    ... Redding Electric Utility, California. Project Description A. History and Description of the CVP, PACI, and... Dams were also included in the authorization, along with high-voltage transmission lines designed to... three components: Component 1: [GRAPHIC] [TIFF OMITTED] TN14SE11.006 Where: FP Customer Load = An FP...

  11. Fiat Chrysler Application for Alternative Methodology for Off-Cycle Technology Credits: Engine and Transmission Warmup

    Science.gov (United States)

    FCA Group LLC request to the EPA regarding greenhouse gas, off-cycle CO2 credits for Active Engine Warm Up used in 2011-2013 model year vehicles and Active Transmission Warm Up Technologies used in 2013 model year vehicles.

  12. A computational model for determining the minimal cost expansion alternatives in transmission systems planning

    International Nuclear Information System (INIS)

    Pinto, L.M.V.G.; Pereira, M.V.F.; Nunes, A.

    1989-01-01

    A computational model for determining an economical transmission expansion plan, based in the decomposition techniques is presented. The algorithm was used in the Brazilian South System and was able to find an optimal solution, with a low computational resource. Some expansions of this methodology are been investigated: the probabilistic one and the expansion with financier restriction. (C.G.C.). 4 refs, 7 figs

  13. Limiting stable states of high-Tc superconductors in the alternating current modes

    International Nuclear Information System (INIS)

    Romanovskii, V.R.; Watanabe, K.; Awaji, S.

    2014-01-01

    The limiting current-carrying capacity of high-T c superconductor and superconducting tape has been studied in the alternating current states. The features that are responsible for their stable formation have been investigated under the conduction-cooled conditions when the operating peak values of the electric field and the current may essentially exceed the corresponding critical values of superconductor. Besides, it has been proved that these peak values are higher than the values of the electric field and the current, which lead to the thermal runaway phenomenon when the current instability onset occurs in the operating modes with direct current. As a result, the stable extremely high heat generation exists in these operating states, which can be called as overloaded states. The limiting stable peak values of charged currents and stability conditions have been determined taking into account the flux creep states of superconductors. The analysis performed has revealed that there exist characteristic times defining the corresponding time windows in the stable development of overloaded states of the alternating current. In order to explain their existence, the basic thermo-electrodynamics mechanisms have been formulated, which have allowed to explain the high stable values of the temperature and the induced electric field before the onset of alternating current instability. In general, it has been shown that the high-T c superconductors may stably operate in the overloaded alternating current states even under the not intensive cooling conditions at a very high level of heat generation, which is not considered in the existing theory of losses. (authors)

  14. Alternatives to electricity for transmission and annual-scale firming - Storage for diverse, stranded, renewable energy resources: hydrogen and ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Leighty, William

    2010-09-15

    The world's richest renewable energy resources 'of large geographic extent and high intensity' are stranded: far from end-users with inadequate or nonexistent gathering and transmission systems to deliver energy. Output of most renewables varies greatly, at time scales of seconds-seasons: energy capture assets operate at low capacity factor; energy delivery is not 'firm'. New electric transmission systems, or fractions thereof, dedicated to renewables, suffer the same low CF: substantial stranded capital assets, increasing the cost of delivered renewable-source energy. Electricity storage cannot affordably firm large renewables at annual scale. Gaseous hydrogen and anhydrous ammonia fuels can: attractive alternatives.

  15. Metastatic castration-resistant prostate cancer: a current view on drug therapy and alternative tumor cell regulation

    Directory of Open Access Journals (Sweden)

    R. A. Gafanov

    2018-01-01

    Full Text Available Prostate cancer (PC is one of the most common causes of death from malignant neoplasms in men in many countries around the world. Transmission of the signal in the androgenic axis of regulation is crucial for the development and progression of PC. Despite the constant dependence on androgen receptor signals in castration resistance, the use of new anti-androgenic drugs invariably leads to the stability  of the ongoing treatment. The interaction of androgen receptor and alternative (phosphoinositide-3-kinases, PI3K pathways in the regulation of cells can be one of the mechanisms of resistance to treatment. In this article, we describe current treatments for metastatic castration-resistant PC and the possible role of the PI3K pathway in the pathogenesis and progression of PC.

  16. Effects of Electron Flow Current Density on Flow Impedance of Magnetically Insulated Transmission Lines

    International Nuclear Information System (INIS)

    He Yong; Zou Wen-Kang; Song Sheng-Yi

    2011-01-01

    In modern pulsed power systems, magnetically insulated transmission lines (MITLs) are used to couple power between the driver and the load. The circuit parameters of MITLs are well understood by employing the concept of flow impedance derived from Maxwell's equations and pressure balance across the flow. However, the electron density in an MITL is always taken as constant in the application of flow impedance. Thus effects of electron flow current density (product of electron density and drift velocity) in an MITL are neglected. We calculate the flow impedances of an MITL and compare them under three classical MITL theories, in which the electron density profile and electron flow current density are different from each other. It is found that the assumption of constant electron density profile in the calculation of the flow impedance is not always valid. The electron density profile and the electron flow current density have significant effects on flow impedance of the MITL. The details of the electron flow current density and its effects on the operation impedance of the MITL should be addressed more explicitly by experiments and theories in the future. (nuclear physics)

  17. Theory of the electric current transmission coefficient in the superconductor-insulator-superconductor geometry

    International Nuclear Information System (INIS)

    Navani, R.

    1974-01-01

    Tunneling in the superconductor-insulator-superconductor (S'-I-S) geometry, where the two superconductors are not necessarily the same, is studied theoretically. Two different models of the S'-I-S geometry - which we call the ''initial model'' and the ''improved model'' are discussed. For the initial model the potential barrier is flat. In the improved model, however, the differing material properties of the three regions - S', I, and S - are taken into account in an approximate fashion. In addition, applied, contact, and image potentials in the insulator are included. The solid state material properties that are taken to be different are the effective electronic masses in the three regions and the Fermi energies in the two superconductors. The quasiparticle wave functions in the S', I, and S regions are determined for both models as solutions to the Bogoliubov-de Gennes equations. The electric current transmission coefficients (also the reflection coefficient for the initial model) are derived and their behavior is extensively analyzed. Their forms in the thick barrier limit - where L greater than or approximately equal to 5 A - are related to the BCS densities of states. The tunneling current density is found to depend strongly on the tunneling angle. A relation between the angular position of the tunneling current peak and the barrier thickness is given. Finally, it is shown that the choice of insulator material effects the tunneling current, and the effect is greater the thicker the insulating film

  18. Prospective single and multi-phase short-circuit current levels in the Dutch transmission, sub-transmission and distribution grids

    NARCIS (Netherlands)

    Janssen, A.L.J.; van Riet, M.J.M.; Smeets, R.P.P.; Kanters, J.; van den Akker, W.F.; Aanhaanen, G.L.P.

    2012-01-01

    As elsewhere in the world, also in the Netherlands utilities face an increase in the actual and future short-circuit current levels at all voltages. This development is provoked by the required increase in transmission capacity as well as the concentration of power generation capacity. Large

  19. A Novel Modulation Function-Based Control of Modular Multilevel Converters for High Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Majid Mehrasa

    2016-10-01

    Full Text Available In this paper, a novel modulation function-based method including analyses of the modulation index and phase is proposed for operation of modular multilevel converters (MMCs in high voltage direct current (HVDC transmission systems. The proposed modulation function-based control technique is developed based on thorough and precise analyses of all MMC voltages and currents in the a-b-c reference frame in which the alternating current (AC-side voltage is the first target to be obtained. Using the AC-side voltage, the combination of the MMC upper and lower arm voltages is achieved as the main structure of the proposed modulation function. The main contribution of this paper is to obtain two very simple new modulation functions to control MMC performance in different operating conditions. The features of the modulation function-based control technique are as follows: (1 this control technique is very simple and can be easily achieved in a-b-c reference frame without the need of using Park transformation; and (2 in addition, the inherent properties of the MMC model are considered in the proposed control technique. Considering these properties leads to constructing a control technique that is robust against MMC parameters changes and also is a very good tracking method for the components of MMC input currents. These features lead to improving the operation of MMC significantly, which can act as a rectifier in the HVDC structure. The simulation studies are conducted through MATLAB/SIMULINK software, and the results obtained verify the effectiveness of the proposed modulation function-based control technique.

  20. Dissolution of Platinum in Hydrochloric Acid Under Industrial-Scale Alternating Current Polarization

    Science.gov (United States)

    Myrzabekov, B. E.; Bayeshov, A. B.; Makhanbetov, A. B.; Mishra, B.; Baigenzhenov, O. S.

    2018-02-01

    The electrochemical behavior of platinum in a hydrochloric acid solution under polarization by an industrial-scale alternating current has been investigated. For the electrical dissolution of platinum, titanium is used as an auxiliary electrode, which increases the yield of platinum dissolution by 12.5 pct. The influence of the concentration of hydrochloric acid, the current densities of the platinum and titanium electrodes, and the temperature of the electrolyte on the efficiency of the process of dissolving platinum have all been studied.

  1. Interplay of light transmission and catalytic exchange current in photoelectrochemical systems

    Energy Technology Data Exchange (ETDEWEB)

    Fountaine, Katherine T., E-mail: kfountai@caltech.edu [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Lewerenz, Hans J. [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Atwater, Harry A. [Joint Center for Artificial Photosynthesis, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States); Department of Applied Physics and Materials Science, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125 (United States)

    2014-10-27

    We develop an analytic current-voltage expression for a variable junction photoelectrochemical (PEC) cell and use it to investigate and illustrate the influence of the optical and electrical properties of catalysts on the optoelectronic performance of PEC devices. Specifically, the model enables a simple, yet accurate accounting of nanostructured catalyst optical and electrical properties through incorporation of an optical transmission factor and active catalytic area factor. We demonstrate the utility of this model via the output power characteristics of an exemplary dual tandem solar cell with indium gallium phosphide and indium gallium arsenide absorbers with varying rhodium catalyst nanoparticle loading. The approach highlights the importance of considering interactions between independently optimized components for optimal PEC device design.

  2. Numerical Analysis of Through Transmission Pulsed Eddy Current Testing and Effects of Pulse Width Variation

    International Nuclear Information System (INIS)

    Shin, Young Kil; Choi, Dong Myung

    2007-01-01

    By using numerical analysis methods, through transmission type pulsed eddy current (PEC) testing is modeled and PEC signal responses due to varying material conductivity, permeability, thickness, lift-off and pulse width are investigated. Results show that the peak amplitude of PEC signal gets reduced and the time to reach the peak amplitude is increased as the material conductivity, permeability, and specimen thickness increase. Also, they indicate that the pulse width needs to be shorter when evaluating the material conductivity and the plate thickness using the peak amplitude, and when the pulse width is long, the peak time is found to be more useful. Other results related to lift-off variation are reported as well

  3. Interplay of light transmission and catalytic exchange current in photoelectrochemical systems

    International Nuclear Information System (INIS)

    Fountaine, Katherine T.; Lewerenz, Hans J.; Atwater, Harry A.

    2014-01-01

    We develop an analytic current-voltage expression for a variable junction photoelectrochemical (PEC) cell and use it to investigate and illustrate the influence of the optical and electrical properties of catalysts on the optoelectronic performance of PEC devices. Specifically, the model enables a simple, yet accurate accounting of nanostructured catalyst optical and electrical properties through incorporation of an optical transmission factor and active catalytic area factor. We demonstrate the utility of this model via the output power characteristics of an exemplary dual tandem solar cell with indium gallium phosphide and indium gallium arsenide absorbers with varying rhodium catalyst nanoparticle loading. The approach highlights the importance of considering interactions between independently optimized components for optimal PEC device design.

  4. Expansion of the high-voltage direct current transmission systems; Netzausbau mit Hochspannungs-Gleichstrom-Uebertragung

    Energy Technology Data Exchange (ETDEWEB)

    Spahic, Ervin; Benz, Thomas; Goerner, Raphael; Sass, Florian [ABB AG, Mannheim (Germany)

    2012-12-15

    In September 2010 the German federal government announced its energy concept for an environmentally friendly, reliable and affordable energy supply. This concept describes a ''path into the era of renewable energy'' up to the year 2050, with electricity production from photovoltaics and wind power taking centre stage. Since the expansion of renewable energy production is mainly taking place in the North (wind power) and the South (PV), this poses a great challenge to the electricity networks. It necessitates the expansion of power transmission systems, notably for transporting electricity generated by wind power in the North to the consumer centres in Western and Southern Germany. However, progress to this end has been very slow. For this reason a technical question now presents itself, namely whether high-voltage direct current technology could possibly offer a solution to the electricity transport problems associated with the energy turnaround.

  5. Alternative methods for skin irritation testing: the current status : ECVAM skin irritation task force report 1

    NARCIS (Netherlands)

    Botham, P.A.; Earl, L.K.; Fentem, J.H.; Roguet, R.; Sandt, J.J.M.

    1998-01-01

    The ECVAM Skin Irritation Task Force was established in November 1996, primarily to prepare a report on the current status of the development and validation of alternative tests for skin irritation and corrosion and, in particular, to identify any appropriate non-animal tests for predicting human

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

    Science.gov (United States)

    McEachern, Alexander; Hofmann, Ronald

    2017-04-11

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

  7. Enhancement of multitasking performance and neural oscillations by transcranial alternating current stimulation

    NARCIS (Netherlands)

    Hsu, W.Y.; Zanto, T.P.; van Schouwenburg, M.R.; Gazzaley, A.

    2017-01-01

    Multitasking is associated with the generation of stimulus-locked theta (4–7 Hz) oscillations arising from prefrontal cortex (PFC). Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that influences endogenous brain oscillations. Here, we investigate

  8. Flow instability in laminar jet flames driven by alternating current electric fields

    KAUST Repository

    Kim, Gyeong Taek; Park, Daegeun; Cha, Min; Park, Jeong; Chung, Suk-Ho

    2016-01-01

    The effect of electric fields on the instability of laminar nonpremixed jet flames was investigated experimentally by applying the alternating current (AC) to a jet nozzle. We aimed to elucidate the origin of the occurrence of twin-lifted jet flames

  9. Serotonergic transmission at Merkel discs: modulation by exogenously applied chemical messengers and involvement of Ih currents.

    Science.gov (United States)

    Chang, Weipang; Kanda, Hirosato; Ikeda, Ryo; Ling, Jennifer; Gu, Jianguo G

    2017-05-01

    The Merkel disc is a main type of tactile end organ consisting of Merkel cells and Aβ-afferent endings that responds to tactile stimulation with slowly adapting type 1 (SA1) afferent impulses. Our recent study has shown that Merkel discs in whisker hair follicles are serotonergic synapses using endogenous serotonin to transmit tactile signals from Merkel cells to Aβ-afferent endings. In this study, we hypothesize that tactile sensitivity of Merkel discs can be modulated by chemical messengers. We tested this hypothesis by determining whether and how SA1 responses of mouse whisker hair follicles may be affected by exogenously applied chemical messengers. We found that SA1 responses were potentiated by serotonin at low concentration (10 μM) but almost completely occluded by serotonin at high concentration (2 mM). In contrast, SA1 responses were not significantly affected by ATP and its metabolically stable analog α,β-methylene-ATP, glutamate, γ-aminobutyric acid (GABA), and histamine. SA1 responses were also not affected by antagonists for P2X receptors, ionotropic glutamate receptors, and ionotropic GABA and glycine receptors. Whole-cell patch-clamp recordings reconfirm the presence of both ionotropic and metabotropic 5-HT receptors on afferent neurons and their terminals innervating whisker hair follicles. All whisker afferent neurons expressed hyperpolarization-activated inward currents (I h ), which are potentiated by serotonin through the activation of metabotropic 5-HT receptors. Taken together, the findings substantiate the serotonergic mechanism of tactile transmission at Merkel discs and identify the involvement of I h currents in postsynaptic excitatory actions of serotonin. In addition, the findings do not favor any significant involvement of ATP, glutamate, histamine, GABA, or glycine in tactile transmission at the Merkel discs of whisker hair follicles. © 2017 International Society for Neurochemistry.

  10. Frequency-dependent failure mechanisms of nanocrystalline gold interconnect lines under general alternating current

    Science.gov (United States)

    Luo, X. M.; Zhang, B.; Zhang, G. P.

    2014-09-01

    Thermal fatigue failure of metallization interconnect lines subjected to alternating currents (AC) is becoming a severe threat to the long-term reliability of micro/nanodevices with increasing electrical current density/power. Here, thermal fatigue failure behaviors and damage mechanisms of nanocrystalline Au interconnect lines on the silicon glass substrate have been investigated by applying general alternating currents (the pure alternating current coupled with a direct current (DC) component) with different frequencies ranging from 0.05 Hz to 5 kHz. We observed both thermal fatigue damages caused by Joule heating-induced cyclic strain/stress and electromigration (EM) damages caused by the DC component. Besides, the damage formation showed a strong electrically-thermally-mechanically coupled effect and frequency dependence. At lower frequencies, thermal fatigue damages were dominant and the main damage forms were grain coarsening with grain boundary (GB) cracking/voiding and grain thinning. At higher frequencies, EM damages took over and the main damage forms were GB cracking/voiding of smaller grains and hillocks. Furthermore, the healing effect of the reversing current was considered to elucidate damage mechanisms of the nanocrystalline Au lines generated by the general AC. Lastly, a modified model was proposed to predict the lifetime of the nanocrystalline metal interconnect lines, i.e., that was a competing drift velocity-based approach based on the threshold time required for reverse diffusion/healing to occur.

  11. The cost-effectiveness of alternative vaccination strategies for polyvalent meningococcal vaccines in Burkina Faso: A transmission dynamic modeling study.

    Science.gov (United States)

    Yaesoubi, Reza; Trotter, Caroline; Colijn, Caroline; Yaesoubi, Maziar; Colombini, Anaïs; Resch, Stephen; Kristiansen, Paul A; LaForce, F Marc; Cohen, Ted

    2018-01-01

    The introduction of a conjugate vaccine for serogroup A Neisseria meningitidis has dramatically reduced disease in the African meningitis belt. In this context, important questions remain about the performance of different vaccine policies that target remaining serogroups. Here, we estimate the health impact and cost associated with several alternative vaccination policies in Burkina Faso. We developed and calibrated a mathematical model of meningococcal transmission to project the disability-adjusted life years (DALYs) averted and costs associated with the current Base policy (serogroup A conjugate vaccination at 9 months, as part of the Expanded Program on Immunization [EPI], plus district-specific reactive vaccination campaigns using polyvalent meningococcal polysaccharide [PMP] vaccine in response to outbreaks) and three alternative policies: (1) Base Prime: novel polyvalent meningococcal conjugate (PMC) vaccine replaces the serogroup A conjugate in EPI and is also used in reactive campaigns; (2) Prevention 1: PMC used in EPI and in a nationwide catch-up campaign for 1-18-year-olds; and (3) Prevention 2: Prevention 1, except the nationwide campaign includes individuals up to 29 years old. Over a 30-year simulation period, Prevention 2 would avert 78% of the meningococcal cases (95% prediction interval: 63%-90%) expected under the Base policy if serogroup A is not replaced by remaining serogroups after elimination, and would avert 87% (77%-93%) of meningococcal cases if complete strain replacement occurs. Compared to the Base policy and at the PMC vaccine price of US$4 per dose, strategies that use PMC vaccine (i.e., Base Prime and Preventions 1 and 2) are expected to be cost saving if strain replacement occurs, and would cost US$51 (-US$236, US$490), US$188 (-US$97, US$626), and US$246 (-US$53, US$703) per DALY averted, respectively, if strain replacement does not occur. An important potential limitation of our study is the simplifying assumption that all

  12. Boron Steel: An Alternative for Costlier Nickel and Molybdenum Alloyed Steel for Transmission Gears

    Directory of Open Access Journals (Sweden)

    A. Verma

    2010-06-01

    Full Text Available Case Carburized (CC low carbon steels containing Ni, Cr and Mo alloying elements are widely used for transmission gears in automobile, as it possesses desired mechanical properties. In order to cut cost and save scarce materials like Ni and Mo for strategic applications, steel alloyed with Boron has been developed, which gives properties comparable to Ni-Cr-Mo alloyed steel. In the process of steel development, care was taken to ensure precipitation of boron which results in precipitation hardening. The characterization of the developed boron steel had exhibited properties comparable to Ni-Cr-Mo alloyed steel and superior to conventional boron steel.

  13. Non-local currents in 2D QFT: an alternative To - the quantum inverse scattering method

    International Nuclear Information System (INIS)

    Bernard, D.; Leclair, A.; Cornell Univ., Ithaca, NY

    1990-01-01

    The formalism based on non-local charges that we propose provides an alternative to the quantum inverse scattering method for solving integrable quantum field theories in 2D. The content of the paper is: 1. Introduction: historical background. 2. The NLC approach to 2D QFT: a summary. 3 Exchange algebras and on-shell conservation laws: why non-local charges are useful. 4. The lattice construction: the geometrical origin of non-local conserved currents. 5. The continuum construction: how to deal with non-local conserved currents. 6. Examples: Yangian and quantum group currents. 7 Conclusions: open problems. 22 refs., 4 figs

  14. Alternate transmission relaying based on interference alignment in 3-relay half-duplex MIMO systems

    KAUST Repository

    Park, Seongho; Park, Kihong; Ko, Youngchai; Alouini, Mohamed-Slim

    2012-01-01

    In a half-duplex relaying, the capacity pre-log factor 1/2 is a major drawback in spectral efficiency. This paper proposes a linear precoding/decoding scheme and an alternate relaying protocol in a dual-hop half-duplex system where three relays help the communication between the source and the destination. In our proposed scheme, we consider a phase incoherent method in relays in which the source alternately transmits message signals to the different relays. In addition, we propose a linear interference alignment scheme which can suppress the inter-relay interference resulting from the phase incoherence of relaying. Based on our analysis of degrees of freedom and our simulation results, we show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying. © 2012 IEEE.

  15. Alternate transmission relaying based on interference alignment in 3-relay half-duplex MIMO systems

    KAUST Repository

    Park, Seongho

    2012-09-01

    In a half-duplex relaying, the capacity pre-log factor 1/2 is a major drawback in spectral efficiency. This paper proposes a linear precoding/decoding scheme and an alternate relaying protocol in a dual-hop half-duplex system where three relays help the communication between the source and the destination. In our proposed scheme, we consider a phase incoherent method in relays in which the source alternately transmits message signals to the different relays. In addition, we propose a linear interference alignment scheme which can suppress the inter-relay interference resulting from the phase incoherence of relaying. Based on our analysis of degrees of freedom and our simulation results, we show that our proposed scheme achieves additional degrees of freedom compared to the conventional half-duplex relaying. © 2012 IEEE.

  16. Reduction of eddy current losses in inductive transmission systems with ferrite sheets.

    Science.gov (United States)

    Maaß, Matthias; Griessner, Andreas; Steixner, Viktor; Zierhofer, Clemens

    2017-01-05

    Improvements in eddy current suppression are necessary to meet the demand for increasing miniaturization of inductively driven transmission systems in industrial and biomedical applications. The high magnetic permeability and the simultaneously low electrical conductivity of ferrite materials make them ideal candidates for shielding metallic surfaces. For systems like cochlear implants the transmission of data as well as energy over an inductive link is conducted within a well-defined parameter set. For these systems, the shielding can be of particular importance if the properties of the link can be preserved. In this work, we investigate the effect of single and double-layered substrates consisting of ferrite and/or copper on the inductance and coupling of planar spiral coils. The examined link systems represent realistic configurations for active implantable systems such as cochlear implants. Experimental measurements are complemented with analytical calculations and finite element simulations, which are in good agreement for all measured parameters. The results are then used to study the transfer efficiency of an inductive link in a series-parallel resonant topology as a function of substrate size, the number of coil turns and coil separation. We find that ferrite sheets can be used to shield the system from unwanted metallic surfaces and to retain the inductive link parameters of the unperturbed system, particularly its transfer efficiency. The required size of the ferrite plates is comparable to the size of the coils, which makes the setup suitable for practical implementations. Since the sizes and geometries chosen for the studied inductive links are comparable to those of cochlear implants, our conclusions apply in particular to these systems.

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

    Directory of Open Access Journals (Sweden)

    Luis M. Botana

    2009-11-01

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

  18. Effects of alternating and direct current in electrocoagulation process on the removal of cadmium from water

    International Nuclear Information System (INIS)

    Vasudevan, Subramanyan; Lakshmi, Jothinathan; Sozhan, Ganapathy

    2011-01-01

    Highlights: → Very high removal efficiency of cadmium was achieved by electrocoagulation. → Alternating current (AC) avoids oxide layer and corrosion on anode surface. → Good current transfer between anode and cathode results more removal efficiency. → Compact treatment facility and complete automation. → Aluminum alloy anode prevents residual aluminum in treated water. - Abstract: In practice, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of cadmium from water using aluminum alloy as anode and cathode. The results showed that the removal efficiency of 97.5 and 96.2% with the energy consumption of 0.454 and 1.002 kWh kl -1 was achieved at a current density of 0.2 A/dm 2 and pH of 7.0 using aluminum alloy as electrodes using AC and DC, respectively. For both AC and DC, the adsorption of cadmium was preferably fitting Langmuir adsorption isotherm, the adsorption process follows second order kinetics and the temperature studies showed that adsorption was exothermic and spontaneous in nature.

  19. Effects of alternating and direct current in electrocoagulation process on the removal of cadmium from water

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Subramanyan, E-mail: vasudevan65@gmail.com [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India); Lakshmi, Jothinathan; Sozhan, Ganapathy [CSIR-Central Electrochemical Research Institute, Karaikudi 630 006 (India)

    2011-08-15

    Highlights: {yields} Very high removal efficiency of cadmium was achieved by electrocoagulation. {yields} Alternating current (AC) avoids oxide layer and corrosion on anode surface. {yields} Good current transfer between anode and cathode results more removal efficiency. {yields} Compact treatment facility and complete automation. {yields} Aluminum alloy anode prevents residual aluminum in treated water. - Abstract: In practice, direct current (DC) is used in an electrocoagulation processes. In this case, an impermeable oxide layer may form on the cathode as well as corrosion formation on the anode due to oxidation. This prevents the effective current transfer between the anode and cathode, so the efficiency of electrocoagulation processes declines. These disadvantages of DC have been diminished by adopting alternating current (AC) in electrocoagulation processes. The main objective of this study is to investigate the effects of AC and DC on the removal of cadmium from water using aluminum alloy as anode and cathode. The results showed that the removal efficiency of 97.5 and 96.2% with the energy consumption of 0.454 and 1.002 kWh kl{sup -1} was achieved at a current density of 0.2 A/dm{sup 2} and pH of 7.0 using aluminum alloy as electrodes using AC and DC, respectively. For both AC and DC, the adsorption of cadmium was preferably fitting Langmuir adsorption isotherm, the adsorption process follows second order kinetics and the temperature studies showed that adsorption was exothermic and spontaneous in nature.

  20. Remote Field Eddy Current Probes for the Detection of Stress Corrosion in Transmission Pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Plamen Alexandroz [Iowa State Univ., Ames, IA (United States)

    2002-01-01

    Magnetic flux leakage (MFL) is a technique used widely in non-destructive testing (NDT) of natural gas and petroleum transmission pipelines. This inspection method relies on magnetizing the pipe-wall in axial direction. The MFL inspection tool is equipped with an array of Hall sensors located around the circumference of the pipe, which registers the flux leakage caused by any defects present in the pipe-wall. Currently, the tool magnetizes the pipewall in axial direction making it largely insensitive to axially oriented defects. One type of defect, which is of a growing concern in the gas and petroleum industry is the stress corrosion crack (SCC). The SCCs are a result of aging, corrosion, fatigue and thermal stresses. SCCs are predominantly axially oriented and are extremely tight, which makes them impossible to be detected using current inspection technology. A possible solution to this problem is to utilize the remote field eddy current (RFEC) effect to detect axially oriented defects. The RFEC method has been widely used in industry in the inspection of tubular products. The method uses a pair of excitation and pick-up coils. The pick-up coil located in the remote field region, usually two, three pipe-diameters away from the excitation coil. With RFEC the presence of defects is detected by the disturbance in the phase of the signal measured by the pick-up coil relative to that of the excitation coil. Unlike conventional eddy current testing the RFEC method is sensitive to defects on the exterior of the inspected product, which makes it a good candidate for the development of in-line inspection technology. This work focuses on the development of non-destructive testing technique, which uses remote field eddy currents induced by rotating magnetic field (RMF). A major advantage of the RMF is that it makes possible to not only detect a defect but also localize its position in circumferential direction. Also, it could potentially allow detection of defects

  1. Alternatives for blocking direct current in AC system neutrals at the Radisson/LG2 complex

    International Nuclear Information System (INIS)

    Eitzmann, M.A.; Walling, R.A.; Sublich, M.; Kah, A.; Huynh, H.; Granger, M.; Dutil, A.

    1992-01-01

    Severe offset saturation results from the passage of direct current through power transformers. Such direct current can arise from geomagnetic disturbances, or resistive coupling of the substation ground to HVDC earth electrodes. This paper documents the development of alternative approaches for the design and application of blocking devices placed between transformer neutrals and the substation ground. System constraints on the impedance and overvoltage limitation of the neutral blocking device (NBD) are covered. Three alternative NBD schemes are developed and optimized. System performance of the NBD is discussed, as are the practical implementation considerations for this unconventional equipment application. Although the paper focuses on the NBD requirements of Hydro-Quebec's Radisson/LG2 complex, the fundamental information is applicable to any situation where dc must be clocked from a power transformer neutral in a system designed for effectively-grounded operation

  2. Alternating Current Delivered into the Scala Media Alters Sound Pressure at the Eardrum

    Science.gov (United States)

    Hubbard, Allyn E.; Mountain, David C.

    1983-11-01

    Alternating current delivered into the scala media of the gerbil cochlea modulates the amplitude of a test tone measured near the eardrum. Variations in the electromechanical effect with acoustic stimulus parameters and observed physiological vulnerability suggest that cochlear hair cells are the biophysical origin of the process. Cochlear hair cells have traditionally been thought of as passive receptor cells, but they may play an active role in cochlear micromechanics.

  3. Alternating current line-filter based on electrochemical capacitor utilizing template-patterned graphene

    OpenAIRE

    Zhenkun Wu; Liyi Li; Ziyin Lin; Bo Song; Zhuo Li; Kyoung-Sik Moon; Ching-Ping Wong; Shu-Lin Bai

    2015-01-01

    Aluminum electrolytic capacitors (AECs) are widely used for alternating current (ac) line-filtering. However, their bulky size is becoming more and more incompatible with the rapid development of portable electronics. Here we report a scalable process to fabricate miniaturized graphene-based ac line-filters on flexible substrates at room temperature. In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material. The...

  4. Motions of quantized vortices attached to a boundary in alternating currents of superfluid 4He

    International Nuclear Information System (INIS)

    Yano, H.; Hashimoto, N.; Handa, A.; Obara, K.; Ishikawa, O.; Hata, T.; Nakagawa, M.

    2007-01-01

    The motions of superfluid vortices attached to a boundary are investigated in alternating currents by using a vibrating wire. The attached vortices appear to form a layer on the wire and enhance the mass of the wire, even for low velocity currents. In turbulence, chaotic motions of vortices such as entanglement and reconnection reduce the thickness of the layer in spite of the fact that the vortices unstably expand. When turbulence subsides, the attached vortices appear to shrink, with the degree of shrinking influenced by thermal excitations in the superfluid

  5. Transcranial alternating current stimulation with sawtooth waves: simultaneous stimulation and EEG recording

    Directory of Open Access Journals (Sweden)

    James eDowsett

    2016-03-01

    Full Text Available Transcranial alternating current stimulation (tACS has until now mostly been administered as an alternating sinusoidal wave. Despite modern tACS stimulators being able to deliver alternating current with any arbitrary shape there has been no systematic exploration into the relative benefits of different waveforms. As tACS is a relatively new technique there is a huge parameter space of unexplored possibilities which may prove superior or complimentary to the traditional sinusoidal waveform. Here we begin to address this with an investigation into the effects of sawtooth wave tACS on individual alpha power. Evidence from animal models suggests that the gradient and direction of an electric current should be important factors for the subsequent neural firing rate; we compared positive and negative ramp sawtooth waves to test this. An additional advantage of sawtooth waves is that the resulting artefact in the electroencephalogram (EEG recording is significantly simpler to remove than a sine wave; accordingly we were able to observe alpha oscillations both during and after stimulation.We found that positive ramp sawtooth, but not negative ramp sawtooth, significantly enhanced alpha power during stimulation relative to sham (p<0.01. In addition we tested for an after-effect of both sawtooth and sinusoidal stimulation on alpha power but in this case did not find any significant effect. This preliminary study paves the way for further investigations into the effect of the gradient and direction of the current in tACS which could significantly improve the usefulness of this technique.

  6. A pre-heating method based on sinusoidal alternating current for lithium-ion battery

    Science.gov (United States)

    Fan, Wentao; Sun, Fengchun; Guo, Shanshan

    2018-04-01

    In this paper, a method of low temperature pre-heating of sinusoidal alternating current (SAC) is proposed. Generally, the lower the frequency of the AC current, the higher the heat generation rate. Yet at low frequency, there is a risk of lithium-ion deposition during the half cycle of charging. This study develops a temperature-adaptive, deposition-free AC pre-heating method. a equivalent electric circuit(EEC) model is established to predict the heat generation rate and temperature status, whose parameters are calibrated from the EIS impedance measurements. The effects of current frequency and amplitude on the heating effect are investigated respectively. A multistep temperature-adaptive amplitude strategy is proposed and the cell can be heated from -20°C to 5°C within 509s at 100Hz frequency with this method.

  7. Sustained diffusive alternating current gliding arc discharge in atmospheric pressure air

    Science.gov (United States)

    Zhu, Jiajian; Gao, Jinlong; Li, Zhongshan; Ehn, Andreas; Aldén, Marcus; Larsson, Anders; Kusano, Yukihiro

    2014-12-01

    Rapid transition from glow discharge to thermal arc has been a common problem in generating stable high-power non-thermal plasmas especially at ambient conditions. A sustained diffusive gliding arc discharge was generated in a large volume in atmospheric pressure air, driven by an alternating current (AC) power source. The plasma column extended beyond the water-cooled stainless steel electrodes and was stabilized by matching the flow speed of the turbulent air jet with the rated output power. Comprehensive investigations were performed using high-speed movies measured over the plasma column, synchronized with simultaneously recorded current and voltage waveforms. Dynamic details of the novel non-equilibrium discharge are revealed, which is characterized by a sinusoidal current waveform with amplitude stabilized at around 200 mA intermediate between thermal arc and glow discharge, shedding light to the governing mechanism of the sustained spark-suppressed AC gliding arc discharge.

  8. Environmental cost-effectiveness of bio diesel production in Greece: Current policies and alternative scenarios

    International Nuclear Information System (INIS)

    Iliopoulos, Constantine; Rozakis, Stelios

    2010-01-01

    Following European Directive 2003/30/EC, the Greek Government adapted legislation that introduces and regulates the bio diesel market. The implemented quota scheme allocates the country's annual, predetermined, tax exempt production of bio diesel to industries based on their ability to meet several criteria. A number of bio diesel supply chain stakeholders have criticized this policy for being efficiency-robbing and vague. This paper uses 2007 data from energy crop farms and three bio diesel-producing companies in order to assess these criticisms. We study the economic and environmental aspects of the currently adopted policy and compare them to three alternative scenarios. We conclude that such criticisms have a merit and that policy makers need to reconsider their alternative options regarding the promotion of bio diesel in transport. Permission of sales directly to local consumers and promotion of forward integration by farmers are efficiency enhancing and environment-friendly means of promoting the use of bio diesel in transport.

  9. Self-limiting current for magnetically insulated coaxial vacuum transmission lines

    International Nuclear Information System (INIS)

    Bergeron, K.D.

    1976-11-01

    Existing cold fluid theories for magnetic insulation are analyzed and applied to the transmission line configuration. The relevance of these results to the propagating short pulse problem, and to DC operation, are discussed

  10. Risk factors for secondary transmission of Shigella infection within households: implications for current prevention policy

    NARCIS (Netherlands)

    Boveé, Lian; Whelan, Jane; Sonder, Gerard J. B.; van Dam, Alje P.; van den Hoek, Anneke

    2012-01-01

    Background: Internationally, guidelines to prevent secondary transmission of Shigella infection vary widely. Cases, their contacts with diarrhoea, and those in certain occupational groups are frequently excluded from work, school, or daycare. In the Netherlands, all contacts attending pre-school

  11. Electric transmission technology

    International Nuclear Information System (INIS)

    Shah, K.R.

    1990-01-01

    Electric transmission technology has matured and can transmit bulk power more reliably and economically than the technology 10 years ago.In 1882, Marcel Depres transmitted 15 kW electric power at 2 kV, using a constant direct current; present transmission voltages have risen to ± 600 kV direct current (DC) and 765 kV alternating current (AC), and it is now possible to transmit bulk electric power at voltages as high as ± 1000 kV DC and 1500 kV AC. Affordable computer systems are now available to optimize transmission reliably. New materials have reduced the bulk of insulation for lines and equipment. New conducting materials and configurations have reduced losses in transmission. Advances in line structures and conductor motion, understanding of flashover characteristics of insulators and air-gaps and electrical performance of lines have resulted in more compact urban transmission lines. (author). 15 refs., 7 tabs., 11 figs

  12. Frequency domain analysis of the lightning current distribution to ground at the transmission line tower with cellular phone base station

    NARCIS (Netherlands)

    Grcev, L.; Deursen, van A.P.J.; Waes, van J.B.M.

    2003-01-01

    Cellular phone base stations are often placed in the poles of power transmission lines. We consider the case when such base stations are powered from the low-voltage network. Of special concern is the current that might be led through the cable metallic shields to other customers' premises in case

  13. Model based simulation of alternative transmission concepts in early stages of product development process; Einsatz von Simulationsmodellen zur Beurteilung von alternativen Getriebekonzepten in fruehen Phasen des Produktentstehungsprozesses

    Energy Technology Data Exchange (ETDEWEB)

    Albers, A.; Ott, S.; Seifermann, A. [Karlsruhe Univ. (Germany). IPEK - Inst. fuer Produktentwicklung

    2006-07-01

    The contribution describes a method for assessing the new transmission concepts and investigate their advantages in alternative powertrain systems. Simulation models of different powertrains were used in order to make the different concepts comparable in an early stage of the product developmentprocess. Further, it is shown how the Contact and Channel Model (C and CM) can be used for modelling individual transmission concepts. These models can help to identify and assess interdependences between part systems and components. (orig.)

  14. Utilization of transmission probabilities in the calculation of unit-cell by the interface-current method

    International Nuclear Information System (INIS)

    Queiroz Bogado Leite, S. de.

    1989-10-01

    A widely used but otherwise physically incorrect assumption in unit-cell calculations by the method of interface currents in cylindrical or spherical geometries, is that of that of isotropic fluxes at the surfaces of the cell annular regions, when computing transmission probabilities. In this work, new interface-current relations are developed without making use of this assumption and the effects on calculated integral parameters are shown for an idealized unit-cell example. (author) [pt

  15. [Transcranial alternating current stimulation. Entrainment and function control of neuronal networks].

    Science.gov (United States)

    Vosskuhl, J; Strüber, D; Herrmann, C S

    2015-12-01

    Transcranial alternating current stimulation (tACS) is a new technique for the modulation of oscillatory brain activity as measured in the electroencephalogram (EEG). In contrast to well-established stimulation techniques, such as transcranial direct current stimulation and transcranial magnetic stimulation, tACS applies a sinusoidal alternating current at a specific frequency. This enables the modulation of the amplitude and frequency of endogenous brain oscillations as well as related cognitive processes. Therefore, the use of tACS has the possibility to evaluate well-known correlations between brain oscillations and cognitive processes in terms of causality. Such causal relationships have been documented in numerous neurocognitive studies on sensory, motor and perceptual processes; however, the clinical application of tACS is still in its infancy. In principle, any pathology that can reliably be connected with brain oscillations of a defined frequency is treatable. A current main focus of clinical research is on symptoms of Parkinson's disease and to a lesser degree, tinnitus. For an effective application of tACS it is important to choose the electrode positions as well as the frequency, intensity and duration of the stimulation in a theory-based and symptom-related manner. A successful therapeutic intervention requires the persistence of the tACS effect after stimulation has ceased. A mechanism that offers not only an explanation to the origin of persistent tACS effects but is also of high therapeutic benefit is neural plasticity. Therefore, one current focus of research aims at a better understanding of tACS after effects.

  16. Enhancement of crystal homogeneity of protein crystals under application of an external alternating current electric field

    Energy Technology Data Exchange (ETDEWEB)

    Koizumi, H.; Uda, S.; Fujiwara, K.; Nozawa, J. [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan); Tachibana, M. [Graduate School of Nanobioscience, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama, 236-0027 (Japan); Kojima, K. [Department of Education, Yokohama Soei University, 1 Miho-tyou, Midori-ku, Yokohama, 226-0015 (Japan)

    2014-10-06

    X-ray diffraction rocking-curve measurements were performed on tetragonal hen egg white (HEW) lysozyme crystals grown with and without the application of an external alternating current (AC) electric field. The crystal quality was assessed by the full width at half maximum (FWHM) value for each rocking curve. For two-dimensional maps of the FWHMs measured on the 440 and the 12 12 0 reflection, the crystal homogeneity was improved under application of an external electric field at 1 MHz, compared with that without. In particular, the significant improvement of the crystal homogeneity was observed for the 12 12 0 reflection.

  17. Sustained diffusive alternating current gliding arc discharge in atmospheric pressure air

    DEFF Research Database (Denmark)

    Zhu, Jiajian; Gao, Jinlong; Li, Zhongshan

    2014-01-01

    Rapid transition from glow discharge to thermal arc has been a common problem in generating stable high-power non-thermal plasmas especially at ambient conditions. A sustained diffusive gliding arc discharge was generated in a large volume in atmospheric pressure air, driven by an alternating...... current (AC) power source. The plasma column extended beyond the water-cooled stainless steel electrodes and was stabilized by matching the flow speed of the turbulent air jet with the rated output power. Comprehensive investigations were performed using high-speed movies measured over the plasma column...

  18. Stability of alternating current discharges between water drops on insulation surfaces

    International Nuclear Information System (INIS)

    Rowland, S M; Lin, F C

    2006-01-01

    Discharges between water drops are important in the ageing of hydrophobic outdoor insulators. They may also be important in the processes leading up to flashover of these insulators in high pollution conditions. This paper considers discharges between drops when a limited alternating current is available, as experienced by an ageing insulator in service. A phenomenon is identified in which the length of a discharge between two drops is reduced through a particular type of distortion of the drops. This is visually characterized as a liquid protrusion from each of a pair of water drops along the insulator surface. This process is distinct from vibration of the drops, general distortion of their shape and the very fast emission of jet streams seen in very high fields. The process depends upon the discharge current, the resistivity of the moisture and the hydrophobicity of the insulation surface

  19. Air pollution control residues from waste incineration: current UK situation and assessment of alternative technologies.

    Science.gov (United States)

    Rani, D Amutha; Boccaccini, A R; Deegan, D; Cheeseman, C R

    2008-11-01

    Current disposal options for APC residues in the UK and alternative treatment technologies developed world-wide have been reviewed. APC residues are currently landfilled in the UK where they undergo in situ solidification, although the future acceptability of this option is uncertain because the EU waste acceptance criteria (WAC) introduce strict limits on leaching that are difficult to achieve. Other APC residue treatment processes have been developed which are reported to reduce leaching to below relevant regulatory limits. The Ferrox process, the VKI process, the WES-PHix process, stabilisation/solidification using cementitious binders and a range of thermal treatment processes are reviewed. Thermal treatment technologies convert APC residues combined with other wastes into inert glass or glass-ceramics that encapsulate heavy metals. The waste management industry will inevitably use the cheapest available option for treating APC residues and strict interpretation and enforcement of waste legislation is required if new, potentially more sustainable technologies are to become commercially viable.

  20. Effect of Alternating Current on the Cathodic Protection and Interface Structure of X80 Steel

    Directory of Open Access Journals (Sweden)

    Huiru Wang

    2017-07-01

    Full Text Available This study employs potential-monitoring techniques, cyclic voltammetry tests, alternating current (AC voltammetry methods, and surface characterization to investigate the AC corrosion of cathodically protected X80 pipeline steel. In a non-passive neutral solution at pH 7.2, a sufficiently negative potential completely protects steel at an AC current density of 100 A/m2. In an alkaline solution at pH 9.6, more serious AC corrosion occurs at more negative cathodic protection (CP potential, whereas without CP the steel suffers negligible corrosion. In addition, the interface capacitance increases with AC amplitude. Based on these results, the AC corrosion mechanisms that function under various conditions are analyzed and described.

  1. Air pollution control residues from waste incineration: Current UK situation and assessment of alternative technologies

    International Nuclear Information System (INIS)

    Amutha Rani, D.; Boccaccini, A.R.; Deegan, D.; Cheeseman, C.R.

    2008-01-01

    Current disposal options for APC residues in the UK and alternative treatment technologies developed world-wide have been reviewed. APC residues are currently landfilled in the UK where they undergo in situ solidification, although the future acceptability of this option is uncertain because the EU waste acceptance criteria (WAC) introduce strict limits on leaching that are difficult to achieve. Other APC residue treatment processes have been developed which are reported to reduce leaching to below relevant regulatory limits. The Ferrox process, the VKI process, the WES-PHix process, stabilisation/solidification using cementitious binders and a range of thermal treatment processes are reviewed. Thermal treatment technologies convert APC residues combined with other wastes into inert glass or glass-ceramics that encapsulate heavy metals. The waste management industry will inevitably use the cheapest available option for treating APC residues and strict interpretation and enforcement of waste legislation is required if new, potentially more sustainable technologies are to become commercially viable

  2. Preparation of scanning tunneling microscopy tips using pulsed alternating current etching

    International Nuclear Information System (INIS)

    Valencia, Victor A.; Thaker, Avesh A.; Derouin, Jonathan; Valencia, Damian N.; Farber, Rachael G.; Gebel, Dana A.; Killelea, Daniel R.

    2015-01-01

    An electrochemical method using pulsed alternating current etching (PACE) to produce atomically sharp scanning tunneling microscopy (STM) tips is presented. An Arduino Uno microcontroller was used to control the number and duration of the alternating current (AC) pulses, allowing for ready optimization of the procedures for both Pt:Ir and W tips using a single apparatus. W tips prepared using constant and pulsed AC power were compared. Tips fashioned using PACE were sharper than those etched with continuous AC power alone. Pt:Ir tips were prepared with an initial coarse etching stage using continuous AC power followed by fine etching using PACE. The number and potential of the finishing AC pulses was varied and scanning electron microscope imaging was used to compare the results. Finally, tip quality using the optimized procedures was verified by UHV-STM imaging. With PACE, at least 70% of the W tips and 80% of the Pt:Ir tips were of sufficiently high quality to obtain atomically resolved images of HOPG or Ni(111)

  3. Enhancement of multitasking performance and neural oscillations by transcranial alternating current stimulation.

    Science.gov (United States)

    Hsu, Wan-Yu; Zanto, Theodore P; van Schouwenburg, Martine R; Gazzaley, Adam

    2017-01-01

    Multitasking is associated with the generation of stimulus-locked theta (4-7 Hz) oscillations arising from prefrontal cortex (PFC). Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that influences endogenous brain oscillations. Here, we investigate whether applying alternating current stimulation within the theta frequency band would affect multitasking performance, and explore tACS effects on neurophysiological measures. Brief runs of bilateral PFC theta-tACS were applied while participants were engaged in a multitasking paradigm accompanied by electroencephalography (EEG) data collection. Unlike an active control group, a tACS stimulation group showed enhancement of multitasking performance after a 90-minute session (F1,35 = 6.63, p = 0.01, ηp2 = 0.16; effect size = 0.96), coupled with significant modulation of posterior beta (13-30 Hz) activities (F1,32 = 7.66, p = 0.009, ηp2 = 0.19; effect size = 0.96). Across participant regression analyses indicated that those participants with greater increases in frontal theta, alpha and beta oscillations exhibited greater multitasking performance improvements. These results indicate frontal theta-tACS generates benefits on multitasking performance accompanied by widespread neuronal oscillatory changes, and suggests that future tACS studies with extended treatments are worth exploring as promising tools for cognitive enhancement.

  4. Enhancement of multitasking performance and neural oscillations by transcranial alternating current stimulation.

    Directory of Open Access Journals (Sweden)

    Wan-Yu Hsu

    Full Text Available Multitasking is associated with the generation of stimulus-locked theta (4-7 Hz oscillations arising from prefrontal cortex (PFC. Transcranial alternating current stimulation (tACS is a non-invasive brain stimulation technique that influences endogenous brain oscillations. Here, we investigate whether applying alternating current stimulation within the theta frequency band would affect multitasking performance, and explore tACS effects on neurophysiological measures. Brief runs of bilateral PFC theta-tACS were applied while participants were engaged in a multitasking paradigm accompanied by electroencephalography (EEG data collection. Unlike an active control group, a tACS stimulation group showed enhancement of multitasking performance after a 90-minute session (F1,35 = 6.63, p = 0.01, ηp2 = 0.16; effect size = 0.96, coupled with significant modulation of posterior beta (13-30 Hz activities (F1,32 = 7.66, p = 0.009, ηp2 = 0.19; effect size = 0.96. Across participant regression analyses indicated that those participants with greater increases in frontal theta, alpha and beta oscillations exhibited greater multitasking performance improvements. These results indicate frontal theta-tACS generates benefits on multitasking performance accompanied by widespread neuronal oscillatory changes, and suggests that future tACS studies with extended treatments are worth exploring as promising tools for cognitive enhancement.

  5. Preparation of scanning tunneling microscopy tips using pulsed alternating current etching

    Energy Technology Data Exchange (ETDEWEB)

    Valencia, Victor A.; Thaker, Avesh A.; Derouin, Jonathan; Valencia, Damian N.; Farber, Rachael G.; Gebel, Dana A.; Killelea, Daniel R., E-mail: dkillelea@luc.edu [Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 W. Sheridan Rd., Chicago, Illinois 60660 (United States)

    2015-03-15

    An electrochemical method using pulsed alternating current etching (PACE) to produce atomically sharp scanning tunneling microscopy (STM) tips is presented. An Arduino Uno microcontroller was used to control the number and duration of the alternating current (AC) pulses, allowing for ready optimization of the procedures for both Pt:Ir and W tips using a single apparatus. W tips prepared using constant and pulsed AC power were compared. Tips fashioned using PACE were sharper than those etched with continuous AC power alone. Pt:Ir tips were prepared with an initial coarse etching stage using continuous AC power followed by fine etching using PACE. The number and potential of the finishing AC pulses was varied and scanning electron microscope imaging was used to compare the results. Finally, tip quality using the optimized procedures was verified by UHV-STM imaging. With PACE, at least 70% of the W tips and 80% of the Pt:Ir tips were of sufficiently high quality to obtain atomically resolved images of HOPG or Ni(111)

  6. Regional economic impacts of current and proposed management alternatives for Charles M. Russell National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Sexton, Natalie; Ishizaki, Asuka; Ritten, John

    2013-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. Charles M. Russell (CMR) National Wildlife Refuge, located in north-central Montana, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for the Refuge must contain an analysis of expected effects associated with current and proposed refuge-management strategies. For refuge CCP planning, an economic analysis provides a means of estimating how current management (No Action Alternative) and proposed management activities (Alternatives) affect the local economy. This type of analysis provides two critical pieces of information: (1) it illustrates a refuge’s contribution to the local community; and (2) it can help in determining whether economic effects are or are not a real concern in choosing among management alternatives. It is important to note that the economic value of a refuge encompasses more than just the impacts on the regional economy. Refuges also provide substantial nonmarket values (values for items not exchanged in established markets) such as maintaining endangered species, preserving wetlands, educating future generations, and adding stability to the ecosystem (Carver and Caudill, 2007). However, quantifying these types of nonmarket values is beyond the scope of this study. This report first presents a description of the local community and economy near the Refuge. Next, the methods used to conduct a regional economic impact analysis are described. An analysis of the final CCP management strategies that could affect stakeholders and residents and the local economy is then presented. The refuge management activities of economic concern in this analysis are:

  7. Radiation exposure during transmission measurements: comparison between CT- and germanium-based techniques with a current PET scanner

    International Nuclear Information System (INIS)

    Wu, Tung-Hsin; Huang, Yung-Hui; Lee, Jason J.S.; Wang, Shih-Yuan; Wang, Su-Cheng; Su, Cheng-Tau; Chen, Liang-Kung; Chu, Tieh-Chi

    2004-01-01

    In positron emission tomographic (PET) scanning, transmission measurements for attenuation correction are commonly performed by using external germanium-68 rod sources. Recently, combined PET and computed tomographic (CT) scanners have been developed in which the CT data can be used for both anatomical-metabolic image formation and attenuation correction of the PET data. The purpose of this study was to evaluate the difference between germanium- and CT-based transmission scanning in terms of their radiation doses by using the same measurement technique and to compare the doses that patients receive during brain, cardiac and whole-body scans. Measurement of absorbed doses to organs was conducted by using a Rando Alderson phantom with thermoluminescent dosimeters. Effective doses were calculated according to the guidelines in the International Commission on Radiation Protection Publication Number 60. Compared with radionuclide doses used in routine 2-[fluorine-18]-fluoro-2-deoxy-d-glucose PET imaging, doses absorbed during germanium-based transmission scans were almost negligible. On the other hand, absorbed doses from CT-based transmission scans were significantly higher, particularly with a whole-body scanning protocol. Effective doses were 8.81 mSv in the high-speed mode and 18.97 mSv in the high-quality mode for whole-body CT-based transmission scans. These measurements revealed that the doses received by a patient during CT-based transmission scanning are more than those received in a typical PET examination. Therefore, the radiation doses represent a limitation to the generalised use of CT-based transmission measurements with current PET/CT scanner systems. (orig.)

  8. Design of the ITER Electron Cyclotron Heating and Current Drive Waveguide Transmission Line

    Science.gov (United States)

    Bigelow, T. S.; Rasmussen, D. A.; Shapiro, M. A.; Sirigiri, J. R.; Temkin, R. J.; Grunloh, H.; Koliner, J.

    2007-11-01

    The ITER ECH transmission line system is designed to deliver the power, from twenty-four 1 MW 170 GHz gyrotrons and three 1 MW 127.5 GHz gyrotrons, to the equatorial and upper launchers. The performance requirements, initial design of components and layout between the gyrotrons and the launchers is underway. Similar 63.5 mm ID corrugated waveguide systems have been built and installed on several fusion experiments; however, none have operated at the high frequency and long-pulse required for ITER. Prototype components are being tested at low power to estimate ohmic and mode conversion losses. In order to develop and qualify the ITER components prior to procurement of the full set of 24 transmission lines, a 170 GHz high power test of a complete prototype transmission line is planned. Testing of the transmission line at 1-2 MW can be performed with a modest power (˜0.5 MW) tube with a low loss (10-20%) resonant ring configuration. A 140 GHz long pulse, 400 kW gyrotron will be used in the initial tests and a 170 GHz gyrotron will be used when it becomes available. Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Dept. of Energy under contract DE-AC05-00OR22725.

  9. Current Knowledge of Leishmania Vectors in Mexico: How Geographic Distributions of Species Relate to Transmission Areas

    Science.gov (United States)

    González, Camila; Rebollar-Téllez, Eduardo A.; Ibáñez-Bernal, Sergio; Becker-Fauser, Ingeborg; Martínez-Meyer, Enrique; Peterson, A. Townsend; Sánchez-Cordero, Víctor

    2011-01-01

    Leishmaniases are a group of vector-borne diseases with different clinical manifestations caused by parasites transmitted by sand fly vectors. In Mexico, the sand fly Lutzomyia olmeca olmeca is the only vector proven to transmit the parasite Leishmania mexicana to humans, which causes leishmaniasis. Other vector species with potential medical importance have been obtained, but their geographic distributions and relation to transmission areas have never been assessed. We modeled the ecological niches of nine sand fly species and projected niches to estimate potential distributions by using known occurrences, environmental coverages, and the algorithms GARP and Maxent. All vector species were distributed in areas with known recurrent transmission, except for Lu. diabolica, which appeared to be related only to areas of occasional transmission in northern Mexico. The distribution of Lu. o. olmeca does not overlap with all reported cutaneous leishmaniasis cases, suggesting that Lu. cruciata and Lu. shannoni are likely also involved as primary vectors in those areas. Our study provides useful information of potential risk areas of leishmaniasis transmission in Mexico. PMID:22049037

  10. The role of facts and HVDC in the future pan-European transmission system development

    NARCIS (Netherlands)

    L'Abbate, A.; Migliavacca, G.; Hager, U.; Rehtanz, C.; Ruberg, S.; Lopes Ferreira, H.M.; Fulli, G.; Purvins, A.

    2010-01-01

    The present paper focuses on FACTS (Flexible Alternating Current Transmission System) and HVDC (High Voltage Direct Current) transmission technologies. Particular attention is paid to different specific technical, economic and environmental features of these power electronics-based devices. Final

  11. Alternatives to currently used antimalarial drugs: in search of a magic bullet.

    Science.gov (United States)

    Bhagavathula, Akshaya Srikanth; Elnour, Asim Ahmed; Shehab, Abdulla

    2016-11-04

    bullet against malaria. Future studies should focus on effective single-dose molecules that can act against all stages of malaria in order to prevent transmission. Newer medicines have also raised concerns in terms of efficacy and safety. Overall, more evidence is needed to effectively reduce the current malaria burden. Treatment strategies that target the blood stage with transmission-blocking properties are needed to prevent future drug resistance.

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

    Science.gov (United States)

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

    2011-05-01

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

  13. Numerical versus analytical Ic(H) patterns in Josephson junctions with periodically alternating critical current density

    International Nuclear Information System (INIS)

    Lazarides, N

    2004-01-01

    An analytical expression for the magnetic-field-dependent critical current I c (H) of Josephson junctions with periodically alternating critical current density J c (x) is derived within the uniform field approximation. Comparison with numerically calculated I c (H) patterns for junctions with identical, thick, periodically arranged defects with the corresponding analytical expression reveals fair agreement for a wide range of parameters, due to increased characteristic length. Based on qualitative arguments, we give the dependence of the new characteristic length on the geometrical parameters of the junction, which is in agreement with self-consistent calculations with the static sine-Gordon equation. The analytical expression captures the observed qualitative features of the I c (H) patterns, while it is practically exact for short junctions or high fields. It also produces the shift of the major peak from the zero-field position of the standard Fraunhofer pattern to another position related to the periodicity of the critical current density in φ-junctions

  14. Effects of direct and alternating current on the treatment of oily water in an electroflocculation process

    Directory of Open Access Journals (Sweden)

    A. A. Cerqueira

    2014-09-01

    Full Text Available In the direct current mode (DC, widely used in electroflocculation (EC, the formation of an impermeable oxide layer on the cathode causes the declining of the efficiency of this process. This disadvantage has been reduced by adopting alternating current (AC. In this study, the effects of AC and DC on operational parameters such as the removal of oils and greases (O&G, color and turbidity from oil-in-water (O/W emulsions of the petroleum industry using aluminum electrodes were investigated. Removal efficiencies of 95%, 97% and 99% of O&G, color and turbidity with energy consumption of 0.280 kWh/m³ and electrode consumption of 0.12 g and 0.18 g were achieved at a current density of 3 A, operation time of 3 minutes and initial pH of 9.0 using AC and DC, respectively. In continuous flow tests performed with the same experimental conditions, the electrode consumption at times up to 60 minutes were 1.6 g and 3.4 g using AC and DC, respectively.

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  16. A uniform laminar air plasma plume with large volume excited by an alternating current voltage

    Science.gov (United States)

    Li, Xuechen; Bao, Wenting; Chu, Jingdi; Zhang, Panpan; Jia, Pengying

    2015-12-01

    Using a plasma jet composed of two needle electrodes, a laminar plasma plume with large volume is generated in air through an alternating current voltage excitation. Based on high-speed photography, a train of filaments is observed to propagate periodically away from their birth place along the gas flow. The laminar plume is in fact a temporal superposition of the arched filament train. The filament consists of a negative glow near the real time cathode, a positive column near the real time anode, and a Faraday dark space between them. It has been found that the propagation velocity of the filament increases with increasing the gas flow rate. Furthermore, the filament lifetime tends to follow a normal distribution (Gaussian distribution). The most probable lifetime decreases with increasing the gas flow rate or decreasing the averaged peak voltage. Results also indicate that the real time peak current decreases and the real time peak voltage increases with the propagation of the filament along the gas flow. The voltage-current curve indicates that, in every discharge cycle, the filament evolves from a Townsend discharge to a glow one and then the discharge quenches. Characteristic regions including a negative glow, a Faraday dark space, and a positive column can be discerned from the discharge filament. Furthermore, the plasma parameters such as the electron density, the vibrational temperature and the gas temperature are investigated based on the optical spectrum emitted from the laminar plume.

  17. Printing of highly conductive solution by alternating current electrohydrodynamic direct-write

    Science.gov (United States)

    Jiang, Jiaxin; Zheng, Gaofeng; Wang, Xiang; Zheng, Jianyi; Liu, Juan; Liu, Yifang; Li, Wenwang; Guo, Shumin

    2018-03-01

    Electrohydrodynamic Direct-Write (EDW) is a novel technology for the printing of micro/nano structures. In this paper, Alternating Current (AC) electrical field was introduced to improve the ejection stability of jet with highly conductive solution. By alternating the electrical field, the polarity of free charges on the surface of jet was changed and the average density of charge, as well as the repulsive force, was reduced to stabilize the jet. When the frequency of AC electrical field increased, the EDW process became more stable and the shape of deposited droplets became more regular. The diameter of printed droplets decreased and the deposition frequency increased with the increase of voltage frequency. The phenomenon of corona discharge was overcome effectively as well. To further evaluate the performance of AC EDW for highly conductive solution, more NaCl was added to the solution and the conductivity was increased to 2810μs/cm. With such high conductivity, the problem of serious corona discharge could still be prevented by AC EDW, and the diameter of printed droplets decreased significantly. This work provides an effective way to accelerate industrial applications of EDW.

  18. Standard practice for examination of welds using the alternating current field measurement technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice describes procedures to be followed during alternating current field measurement examination of welds for baseline and service-induced surface breaking discontinuities. 1.2 This practice is intended for use on welds in any metallic material. 1.3 This practice does not establish weld acceptance criteria. 1.4 The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system might not be exact equivalents; therefore, each system shall be used independently of the other. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  19. The role of alternating current in photo-assisted electrochemical porosification of GaN

    International Nuclear Information System (INIS)

    Ainorkhilah, Mahmood; Naser, M. Ahmed; Yushamdan, Yusof; Kwong, Yam Fong; Zainuriah, Hassan; Tiginyanu, Ion; Siang, Chuah Lee

    2013-01-01

    In this paper, we report the formation of porous GaN films under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical (ACPEC) etching conditions. The ACPEC formed porous GaN with excellent structural and surface morphology. Field emission scanning electron microscope (FESEM), atomic force microscopy (AFM) and high resolution X-ray diffraction (HR-XRD) phi-scan and rocking curves measurements evidenced important features of the pore morphology and nanostructures. According to the FESEM micrographs, the spatial nano architecture of the porous structures exhibits pores with perfect hexagonal shape. The AFM measurements revealed an increase in the surface roughness induced by porosification. X-ray diffraction phi-scan showed that porous GaN sample maintained the epitaxial. (authors)

  20. Digital driver of alternate current motors of the control rods in a nuclear research reactor

    International Nuclear Information System (INIS)

    Sainz M, E.

    1996-01-01

    The updating of the instruments as the operation console of the TRIGA Mark III Salazar Reactor is based on the use of a personal computer that works as data acquisition and control device. The power changes on the reactor have been made through the inserting or extraction of four control rods, that they are operated by mechanisms based in alternate current motors. That is with the object to handling each of the bars and so avoiding too the degradation about the performance of the computer of process. Also it is using four drives of smart kind which do the basic duties for generating the control signals and verifying the sensors state of the limits in continuous form. The computer and drivers are organized as a ring net using the serial port R S-232. The computer of process sends the orders and the identification of destination instrument throughout the net. (Author)

  1. Alternating current electric field effects on neural stem cell viability and differentiation.

    Science.gov (United States)

    Matos, Marvi A; Cicerone, Marcus T

    2010-01-01

    Methods utilizing stem cells hold tremendous promise for tissue engineering applications; however, many issues must be worked out before these therapies can be routinely applied. Utilization of external cues for preimplantation expansion and differentiation offers a potentially viable approach to the use of stem cells in tissue engineering. The studies reported here focus on the response of murine neural stem cells encapsulated in alginate hydrogel beads to alternating current electric fields. Cell viability and differentiation was studied as a function of electric field magnitude and frequency. We applied fields of frequency (0.1-10) Hz, and found a marked peak in neural stem cell viability under oscillatory electric fields with a frequency of 1 Hz. We also found an enhanced propensity for astrocyte differentiation over neuronal differentiation in the 1 Hz cultures, as compared to the other field frequencies we studied. Published 2010 American Institute of Chemical Engineers

  2. Rapid determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration

    Institute of Scientific and Technical Information of China (English)

    XIAO Jun-ping; WANG Xue-feng; ZHOU Qing-xiang; FAN Xiao-yuan; SU Xian-fa; Bai Hua-hua; DUAN Hai-jing

    2007-01-01

    A rapid, simple and sensitive method was demonstrated for the determination of phenolic compounds in water samples by alternating-current oscillopolarographic titration. With the presence of sulfuric acid, phenol could be transferred into a nitroso-compound by reacting with NaNO2. The titration end-point was obtained by the formation of a sharp cut in the oscillopolarographic with infinitesimal NaNO2 on double platinum electrodes. The results showed that phenol had an excellent linear relationship over the range of 4.82×10-6 -9.65×10-3 mol/L, the RSD of the proposed method was lower than 1.5%, and the spiked recoveries of three real water samples were in the range of 95.6%-106.9%.

  3. Alternating current line-filter based on electrochemical capacitor utilizing template-patterned graphene.

    Science.gov (United States)

    Wu, Zhenkun; Li, Liyi; Lin, Ziyin; Song, Bo; Li, Zhuo; Moon, Kyoung-Sik; Wong, Ching-Ping; Bai, Shu-Lin

    2015-06-17

    Aluminum electrolytic capacitors (AECs) are widely used for alternating current (ac) line-filtering. However, their bulky size is becoming more and more incompatible with the rapid development of portable electronics. Here we report a scalable process to fabricate miniaturized graphene-based ac line-filters on flexible substrates at room temperature. In this work, graphene oxide (GO) is reduced by patterned metal interdigits at room temperature and used directly as the electrode material. The as-fabricated device shows a phase angle of -75.4° at 120 Hz with a specific capacitance of 316 µF/cm(2) and a RC time constant of 0.35 ms. In addition, it retains 97.2% of the initial capacitance after 10000 charge/discharge cycles. These outstanding performance characteristics of our device demonstrate its promising to replace the conventional AECs for ac line filtering.

  4. Emission characteristics in solution-processed asymmetric white alternating current field-induced polymer electroluminescent devices

    Science.gov (United States)

    Chen, Yonghua; Xia, Yingdong; Smith, Gregory M.; Gu, Yu; Yang, Chuluo; Carroll, David L.

    2013-01-01

    In this work, the emission characteristics of a blue fluorophor poly(9, 9-dioctylfluorene) (PFO) combined with a red emitting dye: Bis(2-methyl-dibenzo[f,h]quinoxaline)(acetylacetonate)iridium (III) [Ir(MDQ)2(acac)], are examined in two different asymmetric white alternating current field-induced polymer electroluminescent (FIPEL) device structures. The first is a top-contact device in which the triplet transfer is observed resulting in the concentration-dependence of the emission similar to the standard organic light-emitting diode (OLED) structure. The second is a bottom-contact device which, however, exhibits concentration-independence of emission. Specifically, both dye emission and polymer emission are found for the concentrations as high as 10% by weight of the dye in the emitter. We attribute this to the significant different carrier injection characteristics of the two FIPEL devices. Our results suggest a simple and easy way to realize high-quality white emission.

  5. Estimation of failure probability of the end induced current depending on uncertain parameters of a transmission line

    International Nuclear Information System (INIS)

    Larbi, M.; Besnier, P.; Pecqueux, B.

    2014-01-01

    This paper treats about the risk analysis of an EMC default using a statistical approach based on reliability methods. A probability of failure (i.e. probability of exceeding a threshold) of an induced current by crosstalk is computed by taking into account uncertainties on input parameters influencing extreme levels of interference in the context of transmission lines. Results are compared to Monte Carlo simulation (MCS). (authors)

  6. OXYGEN BUBBLE DEVELOPMENT ON A PLATINUM ELECTRODE IN BOROSILICATE GLASS MELT BY THE EFFECT OF ALTERNATING CURRENT

    Directory of Open Access Journals (Sweden)

    Jiri Matej

    2014-10-01

    or on alternating reduction and re-forming of oxidic layer on the electrode in the transition range, has been suggested. Start of bubble evolution at low alternating current density has also been observed in simple sodium-calcium-silicate glass melt. A relation between bubble release and platinum corrosion caused by reduced silicon has been suggested

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

    Energy Technology Data Exchange (ETDEWEB)

    Molina, J.; Fernández, J.; Río, A.I. del; Bonastre, J.; Cases, F., E-mail: fjcases@txp.upv.es

    2014-03-01

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

  8. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants

    International Nuclear Information System (INIS)

    Höhn, Sarah; Braem, Annabel; Neirinck, Bram; Virtanen, Sannakaisa

    2017-01-01

    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO 2 passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. - Highlights: • Alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin was investigated on Ti6Al4V. • The surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests at pH 7 and pH 5. • The analysis showed an increased adsorption of amino acids (DMEM) and proteins (DMEM + FCS). • BSA was shown to prevent dissolution of the β-phase, limiting metal ion release and increase of corrosion resistance. • Ratios calculated by means of ToF-SIMS show that the protein will have different orientations during adsorption.

  9. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants

    Energy Technology Data Exchange (ETDEWEB)

    Höhn, Sarah, E-mail: sarah.hoehn@fau.de [Institute for Surface Science and Corrosion, Dept. of Mat. Science, University of Erlangen-Nürnberg, 91058 Erlangen, Germany. (Germany); Braem, Annabel, E-mail: annabel.braem@kuleuven.be [KU Leuven Department of Materials Engineering, Kasteelpark Arenberg 44, Box 2450, 3001 Leuven (Belgium); Neirinck, Bram, E-mail: bram.neirinck@3DSystems.com [KU Leuven Department of Materials Engineering, Kasteelpark Arenberg 44, Box 2450, 3001 Leuven (Belgium); Virtanen, Sannakaisa, E-mail: virtanen@ww.uni-erlangen.de [Institute for Surface Science and Corrosion, Dept. of Mat. Science, University of Erlangen-Nürnberg, 91058 Erlangen, Germany. (Germany)

    2017-04-01

    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO{sub 2} passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. - Highlights: • Alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin was investigated on Ti6Al4V. • The surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests at pH 7 and pH 5. • The analysis showed an increased adsorption of amino acids (DMEM) and proteins (DMEM + FCS). • BSA was shown to prevent dissolution of the β-phase, limiting metal ion release and increase of corrosion resistance. • Ratios calculated by means of ToF-SIMS show that the protein will have different orientations during adsorption.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  11. Effect of high current density to defect generation of blue LED and its characterization with transmission electron microscope

    Science.gov (United States)

    Gunawan, R.; Sugiarti, E.; Isnaeni; Purawiardi, R. I.; Widodo, H.; Muslimin, A. N.; Yuliasari; Ronaldus, C. E.; Prastomo, N.; Hastuty, S.

    2018-03-01

    The optical, electrical and structural characteristics of InGaN-based blue light-emitting diodes (LEDs) were investigated to identify the degradation of LED before and after current injection. The sample was injected by high current of 200 A/cm2 for 5 and 20 minutes. It was observed that injection of current shifts light intensity and wavelength characteristics that indicated defect generation. Transmission Electron Microscopy (TEM) characterization was carried out in order to clarify the structure degradation caused by defect in active layer which consisted of 14 quantum well with thickness of about 5 nm and confined with barrier layer with thickness of about 12 nm. TEM results showed pre-existing defect in LED before injection with high current. Furthermore, discontinue and edge defect was found in dark spot region of LED after injection with high current.

  12. Use of alternating and pulsed direct current electrified fields for zebra mussel control

    Science.gov (United States)

    Luoma, James A.; Dean, Jan C.; Severson, Todd J.; Wise, Jeremy K.; Barbour, Matthew

    2017-01-01

    Alternatives to chemicals for controlling dreissenid mussels are desirable for environmental compatibility, but few alternatives exist. Previous studies have evaluated the use of electrified fields for stunning and/or killing planktonic life stages of dreissenid mussels, however, the available literature on the use of electrified fields to control adult dreissenid mussels is limited. We evaluated the effects of sinusoidal alternating current (AC) and 20% duty cycle square-wave pulsed direct current (PDC) exposure on the survival of adult zebra mussels at water temperatures of 10, 15, and 22 °C. Peak voltage gradients of ~ 17 and 30 Vp/cm in the AC and PDC exposures, respectively, were continuously applied for 24, 48, or 72 h. Peak power densities ranged from 77,999 to 107,199 µW/cm3 in the AC exposures and 245,320 to 313,945 µW/cm3 in the PDC exposures. The peak dose ranged from 6,739 to 27,298 Joules/cm3 and 21,306 to 80,941 Joules/cm3 in the AC and PDC exposures, respectively. The applied power ranged from 16.6 to 68.9 kWh in the AC exposures and from 22.2 to 86.4 kWh in the PDC exposures. Mortality ranged from 2.7 to 92.7% in the AC exposed groups and from 24.0 to 98.7% in PDC exposed groups. Mortality increased with corresponding increases in water temperature and exposure duration, and we observed more zebra mussel mortality in the PDC exposures. Exposures conducted with AC required less of a peak dose (Joules/cm3) but more applied power (kWh) to achieve the same level of adult zebra mussel mortality as corresponding PDC exposures. The results demonstrate that 20% duty cycle square-wave PDC requires less energy than sinusoidal AC to inducing the same level of adult zebra mussel mortality.

  13. Regional economic analysis of current and proposed management alternatives for Rappahannock River Valley National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Sexton, Natalie; Donovan, Ryan

    2009-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan. The Comprehensive Conservation Plan must describe the desired future conditions of a refuge and provide long-range guidance and management direction to achieve refuge purposes. The Rappahannock River Valley National Wildlife Refuge (refuge) is in the process of developing a range of management goals, objectives, and strategies for the Comprehensive Conservation Plan. The Comprehensive Conservation Plan for the refuge must contain an analysis of expected effects associated with current and proposed refuge management strategies. The purpose of this study was to assess the regional economic implications associated with draft Comprehensive Conservation Plan management strategies. Special interest groups and local residents often criticize a change in refuge management, especially if there is a perceived negative impact to the local economy. Having objective data on economic impacts may show that these fears are overstated. Quite often, the extent of economic benefits a refuge provides to a local community is not fully recognized, yet at the same time the effects of negative changes is overstated. Spending associated with refuge recreational activities, such as wildlife viewing and hunting, can generate considerable tourist activity for surrounding communities. Additionally, refuge personnel typically spend considerable amounts of money purchasing supplies in local stores, repairing equipment and purchasing fuel at the local service stations, and reside and spend their salaries in the local community. For refuge Comprehensive Conservation Plan planning, a regional economic assessment provides a means of estimating how current management (no action alternative) and proposed management activities (alternatives) could affect the local economy. This type of analysis provides two critical pieces of

  14. Regimes of magnetic insulation in a high-current diodes and transmission lines of conical configuration

    International Nuclear Information System (INIS)

    Vasilenko, O.I.; Voronin, V.S.; Lebedev, A.N.

    1977-01-01

    A self-consistent kinematic model of a steady-state electron flow between two electrodes of a high-current diode has been considered with a tapered configuration. All the electrons have presumably been released from the cathode with a zero velocity and some portion of the total current flows along the cathode surface as the conduction current. A set of volt-ampere characteristics has been obtained for the tapered diode with a flat anode. At a preset cathode current the thickness and current of the electron layer increase as the voltage goes up. The considered kinematic model substantiates and specifies a model of the Brillouin parapotential flow

  15. Electric Current Transmission Through Tissues of the Vestibular Labyrinth of a Patient: Perfection of the Vestibular Implant

    Science.gov (United States)

    Demkin, V. P.; Shchetinin, P. P.; Melnichuk, S. V.; Kingma, H.; Van de Berg, R.; Pleshkov, M. O.; Starkov, D. N.

    2018-03-01

    An electric model of current transmission through tissues of the vestibular labyrinth of a patient is suggested. To stimulate directly the vestibular nerve in surgical operation, terminations of the electrodes are implanted through the bone tissue of the labyrinth into the perilymph in the vicinity of the vestibular nerve. The biological tissue of the vestibular labyrinth surrounding the electrodes and having heterogeneous composition possesses conductive and dielectric properties. Thus, when a current pulse from the vestibular implant is applied to one of the electrodes, conductive disturbance currents may arise between the electrodes and the vestibular nerves that can significantly deteriorate the direct signal quality. To study such signals and to compensate for the conductive disturbance currents, an equivalent electric circuit with actual electric impedance properties of tissues of the vestibular system is suggested, and the time parameters of the conductive disturbance current transmission are calculated. It is demonstrated that these parameters can reach large values. The suggested electric model and the results of calculations can be used for perfection of the vestibular implant.

  16. Transcranial Alternating Current Stimulation: A potential risk for genetic generalized epilepsy patients (Study Case

    Directory of Open Access Journals (Sweden)

    Daniel San Juan Orta

    2016-11-01

    Full Text Available Transcranial alternating current stimulation (tACS is a re-emergent neuromodulation technique that consists in the external application of oscillating electrical currents that induces changes in cortical excitability. We present the case of a 16-year-old female with pharmaco-resistant juvenile myoclonic epilepsy to three antiepileptic’s drugs characterized by four myoclonic and 20 absence seizures monthly. She received tACS at 1mA@3Hz pulse train during 60 minutes over Fp1-Fp2 (10-20 EEG international system position during 4 consecutive days using an Endeavor™ IOM Systems device® (Natus Medical Incorporated, Middleton, WI, USA. At the one-month follow-up, she reported a 75% increase in seizures frequency (only myoclonic and tonic-clonic events and developed a 24h myoclonic status epilepticus that resolved with oral clonazepam and intravenous valproate. At the two-month follow-up, the patient reported a 15-day seizure-free period.

  17. Transcranial alternating current stimulation: A review of the underlying mechanisms and modulation of cognitive processes

    Directory of Open Access Journals (Sweden)

    Christoph S Herrmann

    2013-06-01

    Full Text Available Brain oscillations of different frequencies have been associated with a variety of cognitive functions. Convincing evidence supporting those associations has been provided by studies using intracranial stimulation, pharmacological interventions and lesion studies. The emergence of novel non-invasive brain stimulation techniques like repetitive transcranial magnetic stimulation (rTMS and transcranial alternating current stimulation (tACS now allows to modulate brain oscillations directly. Particularly, tACS offers the unique opportunity to causally link brain oscillations of a specific frequency range to cognitive processes, because it uses sinusoidal currents that are bound to one frequency only. Using tACS allows to modulate brain oscillations and in turn to influence cognitive processes, thereby demonstrating the causal link between the two. Here, we review findings about the physiological mechanism of tACS and studies that have used tACS to modulate basic motor and sensory processes as well as higher cognitive processes like memory, ambiguous perception, and decision making.

  18. Transcranial Alternating Current Stimulation: A Potential Risk for Genetic Generalized Epilepsy Patients (Study Case)

    Science.gov (United States)

    San-Juan, Daniel; Sarmiento, Carlos Ignacio; Hernandez-Ruiz, Axel; Elizondo-Zepeda, Ernesto; Santos-Vázquez, Gabriel; Reyes-Acevedo, Gerardo; Zúñiga-Gazcón, Héctor; Zamora-Jarquín, Carol Marina

    2016-01-01

    Transcranial alternating current stimulation (tACS) is a re-emergent neuromodulation technique that consists in the external application of oscillating electrical currents that induces changes in cortical excitability. We present the case of a 16-year-old female with pharmaco-resistant juvenile myoclonic epilepsy to 3 antiepileptic’s drugs characterized by 4 myoclonic and 20 absence seizures monthly. She received tACS at 1 mA at 3 Hz pulse train during 60 min over Fp1–Fp2 (10–20 EEG international system position) during 4 consecutive days using an Endeavor™ IOM Systems device® (Natus Medical Incorporated, Middleton, WI, USA). At the 1-month follow-up, she reported a 75% increase in seizures frequency (only myoclonic and tonic–clonic events) and developed a 24-h myoclonic status epilepticus that resolved with oral clonazepam and intravenous valproate. At the 2-month follow-up, the patient reported a 15-day seizure-free period. PMID:27965623

  19. Flow instability in laminar jet flames driven by alternating current electric fields

    KAUST Repository

    Kim, Gyeong Taek

    2016-10-13

    The effect of electric fields on the instability of laminar nonpremixed jet flames was investigated experimentally by applying the alternating current (AC) to a jet nozzle. We aimed to elucidate the origin of the occurrence of twin-lifted jet flames in laminar jet flow configurations, which occurred when AC electric fields were applied. The results indicated that a twin-lifted jet flame originated from cold jet instability, caused by interactions between negative ions in the jet flow via electron attachment as O +e→O when AC electric fields were applied. This was confirmed by conducting systematic, parametric experiment, which included changing gaseous component in jets and applying different polarity of direct current (DC) to the nozzle. Using two deflection plates installed in parallel with the jet stream, we found that only negative DC on the nozzle could charge oxygen molecules negatively. Meanwhile, the cold jet instability occurred only for oxygen-containing jets. A shedding frequency of jet stream due to AC driven instability showed a good correlation with applied AC frequency exhibiting a frequency doubling. However, for the applied AC frequencies over 80Hz, the jet did not respond to the AC, indicating an existence of a minimum flow induction time in a dynamic response of negative ions to external AC fields. Detailed regime of the instability in terms of jet velocity, AC voltage and frequency was presented and discussed. Hypothesized mechanism to explain the instability was also proposed.

  20. An Analysis of Alternatives to New York City's Current Marijuana Arrest and Detention Policy.

    Science.gov (United States)

    Johnson, Bruce D; Golub, Andrew; Dunlap, Eloise; Sifaneck, Stephen J

    2008-01-01

    During the 1990s, the New York Police Department (NYPD) instituted a policy of arresting and detaining people for minor offenses that occur in public as part of their quality-of-life (hereafter QOL) policing initiative. The number of NYPD arrests for smoking marijuana in public view (MPV) increased from 3,000 in 1994 to over 50,000 in 2000, and have been about 30,000 in the mid 2000s. Most of these arrestees (84%) have been minority; blacks have been 2.7 more likely and Hispanics 1.8 times more likely to be detained than whites for an MPV arrest. Minorities have been most likely to receive more severe dispositions, even controlling for demographics and prior arrest histories.This paper examines the pros and cons of the current policy; this is compared with possible alternatives including the following: arrest and issue a desk appearance ticket (DAT); issue a non-criminal citation (violation); street warnings; and tolerate public marijuana smoking. The authors recommend that the NYPD change to issuing DATs on a routine basis. Drug policy reformers might wish to further pursue changing statutes regarding smoking marijuana in public view into a violation (noncriminal) or encourage the wider use of street warnings. Any of these policy changes would help reduce the disproportionate burden on minorities associated with the current arrest and detention policy. These policies could help maintain civic norms against smoking marijuana in public.

  1. Detection and evaluation of weld defects in stainless steel using alternating current field measurement

    Science.gov (United States)

    Wei-Li, Ma, Weiping; Pan-Qi, Wen-jiao, Dou; Yuan, Xin'an; Yin, Xiaokang

    2018-04-01

    Stainless steel is widely used in nuclear power plants, such as various high-radioactive pool, tools storage and fuel transportation channel, and serves as an important barrier to stop the leakage of high-radioactive material. NonDestructive Evaluation (NDE) methods, eddy current testing (ET), ultrasonic examination (UT), penetration testing (PT) and hybrid detection method, etc., have been introduced into the inspection of a nuclear plant. In this paper, the Alternating Current Field Measurement (ACFM) was fully applied to detect and evaluate the defects in the welds of the stainless steel. Simulations were carried out on different defect types, crack lengths, and orientation to reveal the relationship between the signals and dimensions to determine whether methods could be validated by the experiment. A 3-axis ACFM probe was developed and three plates including 16 defects, which served in nuclear plant before, were examined by automatic detection equipment. The result shows that the minimum detectable crack length on the surface is 2mm and ACFM shows excellent inspection results for a weld in stainless steel and gives an encouraging prospect of broader application.

  2. Transmission of viral hepatitis by blood and blood derivatives: current risks, past heritage.

    Science.gov (United States)

    Prati, D

    2002-11-01

    For more than 40 years in the history of transfusion medicine, transmission of viral hepatitis from infected donors to recipients has been a frequent and serious adverse effect of the administration of blood components and plasma derivatives. This epidemic is now over, at least in developed and resource-rich countries. Hence, the attention of clinicians and investigators now focuses mainly on the measures to reduce the residual risk, on the possible emergence of novel or undiscovered agents causing post-transfusion hepatitis, and on the long-term outcome of patients who became infected more than ten years ago. The present article reviews these issues.

  3. Alternating current electrical stimulation enhanced chemotherapy: a novel strategy to bypass multidrug resistance in tumor cells

    International Nuclear Information System (INIS)

    Janigro, Damir; Perju, Catalin; Fazio, Vincent; Hallene, Kerri; Dini, Gabriele; Agarwal, Mukesh K; Cucullo, Luca

    2006-01-01

    Tumor burden can be pharmacologically controlled by inhibiting cell division and by direct, specific toxicity to the cancerous tissue. Unfortunately, tumors often develop intrinsic pharmacoresistance mediated by specialized drug extrusion mechanisms such as P-glycoprotein. As a consequence, malignant cells may become insensitive to various anti-cancer drugs. Recent studies have shown that low intensity very low frequency electrical stimulation by alternating current (AC) reduces the proliferation of different tumor cell lines by a mechanism affecting potassium channels while at intermediate frequencies interfere with cytoskeletal mechanisms of cell division. The aim of the present study is to test the hypothesis that permeability of several MDR1 over-expressing tumor cell lines to the chemotherapic agent doxorubicin is enhanced by low frequency, low intensity AC stimulation. We grew human and rodent cells (C6, HT-1080, H-1299, SKOV-3 and PC-3) which over-expressed MDR1 in 24-well Petri dishes equipped with an array of stainless steel electrodes connected to a computer via a programmable I/O board. We used a dedicated program to generate and monitor the electrical stimulation protocol. Parallel cultures were exposed for 3 hours to increasing concentrations (1, 2, 4, and 8 μM) of doxorubicin following stimulation to 50 Hz AC (7.5 μA) or MDR1 inhibitor XR9576. Cell viability was assessed by determination of adenylate kinase (AK) release. The relationship between MDR1 expression and the intracellular accumulation of doxorubicin as well as the cellular distribution of MDR1 was investigated by computerized image analysis immunohistochemistry and Western blot techniques. By the use of a variety of tumor cell lines, we show that low frequency, low intensity AC stimulation enhances chemotherapeutic efficacy. This effect was due to an altered expression of intrinsic cellular drug resistance mechanisms. Immunohistochemical, Western blot and fluorescence analysis revealed

  4. Current Perspectives on Prevention of Mother-to-Child Transmission of Syphilis

    Science.gov (United States)

    2016-01-01

    This article aims to provide an update on the prevention of mother-to-child transmission of syphilis by drawing upon some important basic concepts and reviewing the most recent literature on the diagnosis and treatment of syphilis in pregnancy. New technologies, such as automated and point-of-care immunologic tests, are shifting some paradigms, which will certainly be further investigated in the forthcoming years. This is the time to carefully evaluate traditional as well as new strategies to prevent congenital syphilis. Adverse outcomes of mother-to-child transmission of syphilis can be prevented with antenatal screening and penicillin therapy, which proved to have an excellent cost-benefit ratio even in populations with a low prevalence of syphilis. However, syphilis epidemiology is influenced by socioeconomic and cultural factors, and major challenges are faced by poor and developing countries in which the severity of the problem is extremely alarming. On the other hand, the emergence of new technologies has raised doubts about the best algorithm to be used when proper laboratory resources are available. Conditions are quite heterogeneous across populations, and some procedures should not be generalized while there is no evidence that supports some changes and while in-depth studies about local conditions are not conducted. Official organizations need to be alert in order to avoid isolated decisions and ensure that evidence-based guidelines be used in the management of syphilis in pregnancy. PMID:27081586

  5. Measurement and interpretation of current transmission in a crossed-field diode below cutoff

    International Nuclear Information System (INIS)

    Vanderberg, B.H.; Eninger, J.E.

    1997-01-01

    Measurements on the current-voltage-magnetic field characteristics of a space-charge-limited cylindrical cross-field diode below cutoff are presented. The measured current is found to be lower than predicted by simple cold-fluid theory. This reduction combined with observed oscillations in the current can be explained by secondary electron emission from the anode, leading to an increase of space charge in the diode. copyright 1997 American Institute of Physics

  6. The Effects of 10 Hz Transcranial Alternating Current Stimulation on Audiovisual Task Switching

    Directory of Open Access Journals (Sweden)

    Michael S. Clayton

    2018-02-01

    Full Text Available Neural oscillations in the alpha band (7–13 Hz are commonly associated with disengagement of visual attention. However, recent studies have also associated alpha with processes of attentional control and stability. We addressed this issue in previous experiments by delivering transcranial alternating current stimulation at 10 Hz over posterior cortex during visual tasks (alpha tACS. As this stimulation can induce reliable increases in EEG alpha power, and given that performance on each of our visual tasks was negatively associated with alpha power, we assumed that alpha tACS would reliably impair visual performance. However, alpha tACS was instead found to prevent both deteriorations and improvements in visual performance that otherwise occurred during sham & 50 Hz tACS. Alpha tACS therefore appeared to exert a stabilizing effect on visual attention. This hypothesis was tested in the current, pre-registered experiment by delivering alpha tACS during a task that required rapid switching of attention between motion, color, and auditory subtasks. We assumed that, if alpha tACS stabilizes visual attention, this stimulation should make it harder for people to switch between visual tasks, but should have little influence on transitions between auditory and visual subtasks. However, in contrast to this prediction, we observed no evidence of impairments in visuovisual vs. audiovisual switching during alpha vs. control tACS. Instead, we observed a trend-level reduction in visuoauditory switching accuracy during alpha tACS. Post-hoc analyses showed no effects of alpha tACS in response time variability, diffusion model parameters, or on performance of repeat trials. EEG analyses also showed no effects of alpha tACS on endogenous or stimulus-evoked alpha power. We discuss possible explanations for these results, as well as their broader implications for current efforts to study the roles of neural oscillations in cognition using tACS.

  7. Design and Implementation of an over Current Protection Laboratory for Electrical Power Transmission Systems Based on PLC Techniques

    Directory of Open Access Journals (Sweden)

    Hassaan Th. H. Thabet

    2018-01-01

    Full Text Available This paper describes a modern approach for the protection of transmission lines to ensure theirsafety against the faults occurred in power systems. Our approach uses a Programmable LogicController (PLC to realize a transmission line as an over current protection relay. A conditioningcircuit was designed, implemented and tested to collect data obtained from Hall Effect sensors which convert them to suitable analog values compatible with PLC's inputs. Results obtained by our PLC control system are very similar to those obtained by the conventional relays but more efficient. An Automatic Reclosing System (ARS for remote faults is also included in this approach. Our PLC control system and its algorithm are illustrated in this paper also. This approach is designed to be used in electrical networks laboratories as an educational unit in electrical departments of engineering collages and technical institutes; it can be used also in real power systems through suitable interfacing facilities.

  8. Alternating current loss characteristics in (bismuth,lead)SCCO and yttrium barium copper oxide superconducting tapes

    Science.gov (United States)

    Nguyen, Doan Ngoc

    Alternating current (AC) loss and current carrying capacity are two of the most crucial considerations in large-scale power applications of high temperature superconducting (HTS) conductors. AC losses result in an increased thermal load for cooling machines, and thus increased operating costs. Furthermore, AC losses can stimulate quenching phenomena or at least decrease the stability margin for superconducting devices. Thus, understanding AC losses is essential for the development of HTS AC applications. The main focus of this dissertation is to make reliable total AC loss measurements and interpret the experimental results in a theoretical framework. With a specially designed magnet, advanced total AC loss measurement system in liquid nitrogen (77 K) has been successfully built. Both calorimetric and electromagnetic methods were employed to confirm the validity of the measured results and to have a more thorough understanding of AC loss in HTS conductors. The measurement is capable of measuring total AC loss in HTS tapes over a wide range of frequency and amplitude of transport current and magnetic field. An accurate phase control technique allows measurement of total AC loss with any phase difference between the transport current and magnetic field by calorimetric method. In addition, a novel total AC loss measurement system with variable temperatures from 30 K to 100 K was successfully built and tested. Understanding the dependence of AC losses on temperature will enable optimization of the operating temperature and design of HTS devices. As a part of the dissertation, numerical calculations using Brandt's model were developed to study electrodynamics and total AC loss in HTS conductors. In the calculations, the superconducting electrical behavior is assumed to follow a power-law model. In general, the practical properties of conductors, including field-dependence of critical current density Jc, n-value and non-uniform distribution of Jc, can be accounted for in

  9. Implementation of dipolar direct current (DDC) collision-induced dissociation in storage and transmission modes on a quadrupole/time-of-flight tandem mass spectrometer.

    Science.gov (United States)

    Webb, Ian K; Londry, Frank A; McLuckey, Scott A

    2011-09-15

    Means for effecting dipolar direct current collision-induced dissociation (DDC CID) on a quadrupole/time-of-flight in a mass spectrometer have been implemented for the broadband dissociation of a wide range of analyte ions. The DDC fragmentation method in electrodynamic storage and transmission devices provides a means for inducing fragmentation of ions over a large mass-to-charge range simultaneously. It can be effected within an ion storage step in a quadrupole collision cell that is operated as a linear ion trap or as ions are continuously transmitted through the collision cell. A DDC potential is applied across one pair of rods in the quadrupole collision cell of a QqTOF hybrid mass spectrometer to effect fragmentation. In this study, ions derived from a small drug molecule, a model peptide, a small protein, and an oligonucleotide were subjected to the DDC CID method in either an ion trapping or an ion transmission mode (or both). Several key experimental parameters that affect DDC CID results, such as time, voltage, low mass cutoff, and bath gas pressure, are illustrated with protonated leucine enkephalin. The DDC CID dissociation method gives a readily tunable, broadband tool for probing the primary structures of a wide range of analyte ions. The method provides an alternative to the narrow resonance conditions of conventional ion trap CID and it can access more extensive sequential fragmentation, depending upon conditions. The DDC CID approach constitutes a collision analog to infrared multiphoton dissociation (IRMPD). Copyright © 2011 John Wiley & Sons, Ltd.

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

    NARCIS (Netherlands)

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

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

  11. Multiple dual mode counter-current chromatography with variable duration of alternating phase elution steps.

    Science.gov (United States)

    Kostanyan, Artak E; Erastov, Andrey A; Shishilov, Oleg N

    2014-06-20

    The multiple dual mode (MDM) counter-current chromatography separation processes consist of a succession of two isocratic counter-current steps and are characterized by the shuttle (forward and back) transport of the sample in chromatographic columns. In this paper, the improved MDM method based on variable duration of alternating phase elution steps has been developed and validated. The MDM separation processes with variable duration of phase elution steps are analyzed. Basing on the cell model, analytical solutions are developed for impulse and non-impulse sample loading at the beginning of the column. Using the analytical solutions, a calculation program is presented to facilitate the simulation of MDM with variable duration of phase elution steps, which can be used to select optimal process conditions for the separation of a given feed mixture. Two options of the MDM separation are analyzed: 1 - with one-step solute elution: the separation is conducted so, that the sample is transferred forward and back with upper and lower phases inside the column until the desired separation of the components is reached, and then each individual component elutes entirely within one step; 2 - with multi-step solute elution, when the fractions of individual components are collected in over several steps. It is demonstrated that proper selection of the duration of individual cycles (phase flow times) can greatly increase the separation efficiency of CCC columns. Experiments were carried out using model mixtures of compounds from the GUESSmix with solvent systems hexane/ethyl acetate/methanol/water. The experimental results are compared to the predictions of the theory. A good agreement between theory and experiment has been demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Comparison of direct and alternating current vacuum ultraviolet lamps in atmospheric pressure photoionization.

    Science.gov (United States)

    Vaikkinen, Anu; Haapala, Markus; Kersten, Hendrik; Benter, Thorsten; Kostiainen, Risto; Kauppila, Tiina J

    2012-02-07

    A direct current induced vacuum ultraviolet (dc-VUV) krypton discharge lamp and an alternating current, radio frequency (rf) induced VUV lamp that are essentially similar to lamps in commercial atmospheric pressure photoionization (APPI) ion sources were compared. The emission distributions along the diameter of the lamp exit window were measured, and they showed that the beam of the rf lamp is much wider than that of the dc lamp. Thus, the rf lamp has larger efficient ionization area, and it also emits more photons than the dc lamp. The ionization efficiencies of the lamps were compared using identical spray geometries with both lamps in microchip APPI mass spectrometry (μAPPI-MS) and desorption atmospheric pressure photoionization-mass spectrometry (DAPPI-MS). A comprehensive view on the ionization was gained by studying six different μAPPI solvent compositions, five DAPPI spray solvents, and completely solvent-free DAPPI. The observed reactant ions for each solvent composition were very similar with both lamps except for toluene, which showed a higher amount of solvent originating oxidation products with the rf lamp than with the dc lamp in μAPPI. Moreover, the same analyte ions were detected with both lamps, and thus, the ionization mechanisms with both lamps are similar. The rf lamp showed a higher ionization efficiency than the dc lamp in all experiments. The difference between the lamp ionization efficiencies was greatest when high ionization energy (IE) solvent compositions (IEs above 10 eV), i.e., hexane, methanol, and methanol/water, (1:1 v:v) were used. The higher ionization efficiency of the rf lamp is likely due to the larger area of high intensity light emission, and the resulting larger efficient ionization area and higher amount of photons emitted. These result in higher solvent reactant ion production, which in turn enables more efficient analyte ion production. © 2012 American Chemical Society

  13. Analysis of the dynamic response improvement of a turbocharged diesel engine driven alternating current generating set

    International Nuclear Information System (INIS)

    Katrasnik, Tomaz; Medica, Vladimir; Trenc, Ferdinand

    2005-01-01

    Reliability of electric supply systems is among the most required necessities of modern society. Turbocharged diesel engine driven alternating current generating sets are often used to prevent electric black outs and/or as prime electric energy suppliers. It is well known that turbocharged diesel engines suffer from an inadequate response to a sudden load increase, this being a consequence of the nature of the energy exchange between the engine and the turbocharger. The dynamic response of turbocharged diesel engines could be improved by electric assisting systems, either by direct energy supply with an integrated starter-generator-booster (ISG) mounted on the engine flywheel, or by an indirect energy supply with an electrically assisted turbocharger. An experimentally verified zero dimensional computer simulation method was used for the analysis of both types of electrical assistance. The paper offers an analysis of the interaction between a turbocharged diesel engine and different electric assisting systems, as well as the requirements for the supporting electric motors that could improve the dynamic response of a diesel engine while driving an AC generating set. When performance class compliance is a concern, it is evident that an integrated starter-generator-booster outperforms an electrically assisted turbocharger for the investigated generating set. However, the electric energy consumption and frequency recovery times are smaller when an electrically assisted turbocharger is applied

  14. Friends, not foes: Magnetoencephalography as a tool to uncover brain dynamics during transcranial alternating current stimulation.

    Science.gov (United States)

    Neuling, Toralf; Ruhnau, Philipp; Fuscà, Marco; Demarchi, Gianpaolo; Herrmann, Christoph S; Weisz, Nathan

    2015-09-01

    Brain oscillations are supposedly crucial for normal cognitive functioning and alterations are associated with cognitive dysfunctions. To demonstrate their causal role on behavior, entrainment approaches in particular aim at driving endogenous oscillations via rhythmic stimulation. Within this context, transcranial electrical stimulation, especially transcranial alternating current stimulation (tACS), has received renewed attention. This is likely due to the possibility of defining oscillatory stimulation properties precisely. Also, measurements comparing pre-tACS with post-tACS electroencephalography (EEG) have shown impressive modulations. However, the period during tACS has remained a blackbox until now, due to the enormous stimulation artifact. By means of application of beamforming to magnetoencephalography (MEG) data, we successfully recovered modulations of the amplitude of brain oscillations during weak and strong tACS. Additionally, we demonstrate that also evoked responses to visual and auditory stimuli can be recovered during tACS. The main contribution of the present study is to provide critical evidence that during ongoing tACS, subtle modulations of oscillatory brain activity can be reconstructed even at the stimulation frequency. Future tACS experiments will be able to deliver direct physiological insights in order to further the understanding of the contribution of brain oscillations to cognition and behavior. Copyright © 2015. Published by Elsevier Inc.

  15. Bi-frontal transcranial alternating current stimulation in the ripple range reduced overnight forgetting

    Directory of Open Access Journals (Sweden)

    Géza Gergely eAmbrus

    2015-09-01

    Full Text Available High frequency oscillations in the hippocampal structures recorded during sleep have been proved to be essential for long-term episodic memory consolidation in both animals and in humans. The aim of this study was to test if transcranial Alternating Current Stimulation (tACS of the dorsolateral prefrontal cortex (DLPFC in the hippocampal ripple range, applied bi-frontally during encoding, could modulate declarative memory performance, measured immediately after encoding, and after a night’s sleep. An associative word-pair learning test, taken from Marshall and colleagues, was used. During an evening encoding phase, participants received 1 mA 140 Hz tACS or sham stimulation over both DLPFCs for 10 minutes while being presented twice with a list of word-pairs. Cued recall performance was investigated 10 minutes after training and the morning following the training session. Forgetting from evening to morning was observed in the sham condition, but not in the 140 Hz stimulation condition. 140 Hz tACS during encoding may have an effect on the consolidation of declarative material.

  16. From amusic to musical?--Improving pitch memory in congenital amusia with transcranial alternating current stimulation.

    Science.gov (United States)

    Schaal, Nora K; Pfeifer, Jasmin; Krause, Vanessa; Pollok, Bettina

    2015-11-01

    Brain imaging studies highlighted structural differences in congenital amusia, a life-long perceptual disorder that is associated with pitch perception and pitch memory deficits. A functional anomaly characterized by decreased low gamma oscillations (30-40 Hz range) in the right dorsolateral prefrontal cortex (DLPFC) during pitch memory has been revealed recently. Thus, the present study investigates whether applying transcranial alternating current stimulation (tACS) at 35 Hz to the right DLPFC would improve pitch memory. Nine amusics took part in two tACS sessions (either 35 Hz or 90 Hz) and completed a pitch and visual memory task before and during stimulation. 35 Hz stimulation facilitated pitch memory significantly. No modulation effects were found with 90 Hz stimulation or on the visual task. While amusics showed a selective impairment of pitch memory before stimulation, the performance during 35 Hz stimulation was not significantly different to healthy controls anymore. Taken together, the study shows that modulating the right DLPFC with 35 Hz tACS in congenital amusia selectively improves pitch memory performance supporting the hypothesis that decreased gamma oscillations within the DLPFC are causally involved in disturbed pitch memory and highlight the potential use of tACS to interact with cognitive processes. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Luminescence evolution from alumina ceramic surface before flashover under direct and alternating current voltage in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Su, Guo-Qiang; Wang, Yi-Bo; Song, Bai-Peng; Mu, Hai-Bao, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn; Zhang, Guan-Jun, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Li, Feng; Wang, Meng [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)

    2016-06-15

    The luminescence evolution phenomena from alumina ceramic surface in vacuum under high voltage of direct and alternating current are reported, with the voltage covering a large range from far below to close to the flashover voltage. Its time resolved and spatial distributed behaviors are examined by a photon counting system and an electron-multiplying charge-coupled device (EMCCD) together with a digital camera, respectively. The luminescence before flashover exhibits two stages as voltage increasing, i.e., under a relative low voltage (Stage A), the luminescence is ascribed to radiative recombination of hetero-charges injected into the sample surface layer by Schottky effect; under a higher voltage (Stage B), a stable secondary electron emission process, resulting from the Fowler-Nordheim emission at the cathode triple junction (CTJ), is responsible for the luminescence. Spectrum analysis implies that inner secondary electrons within the surface layer of alumina generated during the SSEE process also participate in the luminescence of Stage B. A comprehensive interpretation of the flashover process is formulated, which might promote a better understanding of flashover issue in vacuum.

  18. Gastric motility evaluated by electrogastrography and alternating current biosusceptometry in dogs

    International Nuclear Information System (INIS)

    Andreis, Uilian; Corá, Luciana A; Miranda, José Ricardo A; Américo, Madileine F; Oliveira, Ricardo B; Baffa, Oswaldo

    2008-01-01

    Association techniques could be the answer for evaluating electromechanical coupling and gastric emptying under basal conditions and after administration of drugs. Electrogastrography (EGG) and alternating current biosusceptometry (ACB) emerged due to their interesting nature, noninvasiveness and low cost. The aims were to examine in dogs the effect of erythromycin on gastric emptying by ACB and electrical and motor responses to erythromycin and propranolol by ACB and EGG respectively. Twelve beagle dogs ingested a solid test meal on separate days. Under anesthesia, gastric motility was evaluated by EGG and ACB after erythromycin and propranolol administration. Without anesthesia, gastric emptying was assessed under basal conditions and after erythromycin by ACB. ACB and EGG showed a strong temporal correlation. Erythromycin and propranolol presented the same profile with different power ratios; the amplitude increased whereas frequency decreased. Also, erythromycin administration hastened gastric emptying while reducing the orocaecal transit time. There is a demand for reliable, easy-to-perform and comfortable techniques to record gastric emptying and gastric activity in medicine and veterinary practice. In summary, the association of ACB with EGG accompanied by an appropriate animal model is promising for evaluating effects of drugs in gastric myoelectrical and contractile activity

  19. Electroluminescent efficiency of alternating current thick film devices using ZnS:Cu,Cl phosphor

    International Nuclear Information System (INIS)

    Sharma, Gaytri; Han, Sang Do; Kim, Jung Duk; Khatkar, Satyender P.; Rhee, Young Woo

    2006-01-01

    ZnS:Cu,Cl phosphor is prepared with the help of low intensity milling of the precursor material in two step firing process. The synthesized phosphor is used for the preparation of alternating current thick film electroluminescent (ACTFEL) devices with screen-printing method. The commission international de l'Eclairge (CIE) color co-ordinates of the ACTFEL devices prepared by these phosphor layers shows a shift from bluish-green to green region with the change in the amount of Cu in the phosphor. The various parameters to improve the efficiency and luminance of the devices have also been investigated. The brightness of the ac thick film EL device depends on the particle size of the phosphor, crystallinity, amount of binding material and applied voltage. The EL device fabricated with phosphor having average particle size of 25 μm shows maximum luminescence, when 60% phosphor concentration is used with respect to binding material. EL intensity is also linearly dependent on frequency. It is due the increase of excitation chances of the host matrix or dopant ions with increasing frequency

  20. Albumin coatings by alternating current electrophoretic deposition for improving corrosion resistance and bioactivity of titanium implants.

    Science.gov (United States)

    Höhn, Sarah; Braem, Annabel; Neirinck, Bram; Virtanen, Sannakaisa

    2017-04-01

    Although Ti alloys are generally regarded to be highly corrosion resistant, inflammatory conditions following surgery can instigate breakdown of the TiO 2 passivation layer leading to an increased metal ion release. Furthermore proteins present in the surrounding tissue will readily adsorb on a titanium surface after implantation. In this paper alternating current electrophoretic deposition (AC-EPD) of bovine serum albumin (BSA) on Ti6Al4V was investigated in order to increase the corrosion resistance and control the protein adsorption capability of the implant surface. The Ti6Al4V surface was characterized with SEM, XPS and ToF-SIMS after long-term immersion tests under physiological conditions and simulated inflammatory conditions either in Dulbecco's Modified Eagle Medium (DMEM) or DMEM supplemented with fetal calf serum (FCS). The analysis showed an increased adsorption of amino acids and proteins from the different immersion solutions. The BSA coating was shown to prevent selective dissolution of the vanadium (V) rich β-phase, thus effectively limiting metal ion release to the environment. Electrochemical impedance spectroscopy measurements confirmed an increase of the corrosion resistance for BSA coated surfaces as a function of immersion time due to the time-dependent adsorption of the different amino acids (from DMEM) and proteins (from FCS) as observed by ToF-SIMS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Bi-frontal transcranial alternating current stimulation in the ripple range reduced overnight forgetting.

    Science.gov (United States)

    Ambrus, Géza Gergely; Pisoni, Alberto; Primaßin, Annika; Turi, Zsolt; Paulus, Walter; Antal, Andrea

    2015-01-01

    High frequency oscillations in the hippocampal structures recorded during sleep have been proved to be essential for long-term episodic memory consolidation in both animals and in humans. The aim of this study was to test if transcranial Alternating Current Stimulation (tACS) of the dorsolateral prefrontal cortex (DLPFC) in the hippocampal ripple range, applied bi-frontally during encoding, could modulate declarative memory performance, measured immediately after encoding, and after a night's sleep. An associative word-pair learning test was used. During an evening encoding phase, participants received 1 mA 140 Hz tACS or sham stimulation over both DLPFCs for 10 min while being presented twice with a list of word-pairs. Cued recall performance was investigated 10 min after training and the morning following the training session. Forgetting from evening to morning was observed in the sham condition, but not in the 140 Hz stimulation condition. 140 Hz tACS during encoding may have an effect on the consolidation of declarative material.

  2. Measurement of lower-hybrid-driven current profile by Abel inversion of electron-cyclotron wave transmission spectra

    International Nuclear Information System (INIS)

    Fidone, I.; Giruzzi, G.; Caron, X.; Meyer, R.L.

    1991-01-01

    A method for measuring the radial profile of the lower-hybrid-driven current in a low-density tokamak plasma using electron-cyclotron wave attenuation is discussed. This diagnostic scheme is reminiscent of the transmission interferometry approach, commonly used in tokamaks to measure the plasma density, but now the wave amplitude instead of the phase is measured. Wave attenuation of the ordinary mode at ω p much-lt ω c along vertical chords is measured; at these frequencies, the waves are absorbed by the superthermal tail sustained by lower-hybrid waves and the local wave absorption coefficient is proportional to the noninductive current density. The radial profile of this current is obtained from Abel inversion. An application to the Tore Supra tokamak is presented

  3. A novel concept of fault current limiter based on saturable core in high voltage DC transmission system

    Science.gov (United States)

    Yuan, Jiaxin; Zhou, Hang; Gan, Pengcheng; Zhong, Yongheng; Gao, Yanhui; Muramatsu, Kazuhiro; Du, Zhiye; Chen, Baichao

    2018-05-01

    To develop mechanical circuit breaker in high voltage direct current (HVDC) system, a fault current limiter is required. Traditional method to limit DC fault current is to use superconducting technology or power electronic devices, which is quite difficult to be brought to practical use under high voltage circumstances. In this paper, a novel concept of high voltage DC transmission system fault current limiter (DCSFCL) based on saturable core was proposed. In the DCSFCL, the permanent magnets (PM) are added on both up and down side of the core to generate reverse magnetic flux that offset the magnetic flux generated by DC current and make the DC winding present a variable inductance to the DC system. In normal state, DCSFCL works as a smoothing reactor and its inductance is within the scope of the design requirements. When a fault occurs, the inductance of DCSFCL rises immediately and limits the steepness of the fault current. Magnetic field simulations were carried out, showing that compared with conventional smoothing reactor, DCSFCL can decrease the high steepness of DC fault current by 17% in less than 10ms, which verifies the feasibility and effectiveness of this method.

  4. Alternative transmission routes in the malaria elimination era: an overview of transfusion-transmitted malaria in the Americas.

    Science.gov (United States)

    Alho, Regina M; Machado, Kim Vinícius Amaral; Val, Fernando F A; Fraiji, Nelson A; Alexandre, Marcia A A; Melo, Gisely C; Recht, Judith; Siqueira, André M; Monteiro, Wuelton M; Lacerda, Marcus V G

    2017-02-15

    Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature. Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved. A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant

  5. Perception of the environmental impacts of current and alternative modes of pig production by stakeholder groups.

    Science.gov (United States)

    Petit, Jean; van der Werf, Hayo M G

    2003-08-01

    The current industrial pig production model is in crisis, due to its association with environmental pollution, doubtful product quality and lack of animal well-being. In Bretagne (France), a region of intensive pig production, a survey of seven stakeholder groups concerned with pig production was conducted, as part of a research programme dedicated to the assessment of the environmental impact of different modes of pig production. A very large majority of pig producers (93%) and their suppliers (100%) considers pig farms as an asset for the region, whereas a majority of scientists (58%), activists (78%) and consumers (54%) sees it as a handicap. Differences among stakeholder groups are minor with respect to the perceived importance of environmental and social issues. Stakeholders agree on the relative level of responsibility of pig farms with respect to specific problems. For all groups unpleasant odours and water quality come first with respect to responsibility, for most groups soil quality comes second, followed by product safety and air quality. For a future improved mode of pig production, 76% of pig producers and their suppliers prefer to adapt the current model, for all other groups the majority prefers an alternative model. While pig producers and their suppliers prefer a slurry-based housing system, all other groups prefer a straw-based system. Pig producers see the slurry-based system as technically superior and associate the straw-based system with poor working conditions, whereas consumers associate the slurry-based system in the first place with poor water quality and associate the straw-based system with less pollution. These results will be of use in the research programme on the environmental impact of modes of pig production, as they indicate the environmental impacts to be considered and their relative importance. The results will also help in deciding which options should be assessed. It is concluded that the poor image of the current pig

  6. Application of magnetically insulated transmission lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Shope, S.L.; Mazarakis, M.G.; Frost, C.A.; Poukey, J.W.; Turman, B.N.

    1993-01-01

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently the authors used a MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r b < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. The authors' success with the MITL technology led them to investigate the application to higher energy accelerator designs. They have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30-50-ns FWHM output pulse

  7. The current screening programme for congenital transmission of Chagas disease in Catalonia, Spain.

    Science.gov (United States)

    Basile, L; Oliveira, I; Ciruela, P; Plasencia, A

    2011-09-22

    Due to considerable numbers of migrants from Chagas disease-endemic countries living in Catalonia, the Catalonian Health Department has recently implemented a screening programme for preventing congenital transmission, targeting Latin American pregnant women who attend antenatal consultations. Diagnosis of Trypanosoma cruzi infection in women is based on two positive serological tests. Screening of newborns from mothers with positive serology is based on a parasitological test during the first 48 hours of life and/or conventional serological analysis at the age of nine months. If either of these tests is positive, treatment with benznidazole is started following the World Health Organization's recommendations. The epidemiological surveillance of the programme is based on the Microbiological Reporting System of Catalonia, a well established network of laboratories. Once a positive case is reported, the responsible physician is asked to complete a structured epidemiological questionnaire. Clinical and demographic data are registered in the Voluntary Case Registry of Chagas Disease, a database administered by the Catalonian Health Department. It is expected that this programme will improve the understanding of the real burden of Chagas disease in the region. Furthermore, this initiative could encourage the implementation of similar programmes in other regions of Spain and even in other European countries.

  8. Application of Magnetically Insulated Transmission Lines for high current, high voltage electron beam accelerators

    International Nuclear Information System (INIS)

    Shope, S.L.; Mazarakis, M.G.; Frost, C.A.; Poukey, J.W.; Turman, B.N.

    1991-01-01

    Self Magnetically Insulated Transmission Lines (MITL) adders have been used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently we used at MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r ρ < 2 cm), 11 to 15 MeV, 50 to 100-kA beams with a small transverse velocity v perpendicular/c = β perpendicular ≤ 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. Our success with the MITL technology led us to investigate the application to higher energy accelerator designs. We have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30--50 ns FWHM output pulse. 10 refs

  9. Application of magnetically insulated transmission lines for high current, high voltage electron beam accelerators

    Science.gov (United States)

    Shope, S. L.; Mazarakis, M. G.; Frost, C. A.; Poukey, J. W.; Turman, B. N.

    Self Magnetically Insulated Transmission Lines (MITL) adders were used successfully in a number of Sandia accelerators such as HELIA, HERMES III, and SABRE. Most recently we used at MITL adder in the RADLAC/SMILE electron beam accelerator to produce high quality, small radius (r(sub rho) less than 2 cm), 11 - 15 MeV, 50 - 100-kA beams with a small transverse velocity v(perpendicular)/c = beta(perpendicular) less than or equal to 0.1. In RADLAC/SMILE, a coaxial MITL passed through the eight, 2 MV vacuum envelopes. The MITL summed the voltages of all eight feeds to a single foilless diode. The experimental results are in good agreement with code simulations. Our success with the MITL technology led us to investigate the application to higher energy accelerator designs. We have a conceptual design for a cavity-fed MITL that sums the voltages from 100 identical, inductively-isolated cavities. Each cavity is a toroidal structure that is driven simultaneously by four 8-ohm pulse-forming lines, providing a 1-MV voltage pulse to each of the 100 cavities. The point design accelerator is 100 MV, 500 kA, with a 30 - 50 ns FWHM output pulse.

  10. Current transformer model with hysteresis for improving the protection response in electrical transmission systems

    Science.gov (United States)

    Matussek, Robert; Dzienis, Cezary; Blumschein, Jörg; Schulte, Horst

    2014-12-01

    In this paper, a generic enhanced protection current transformer (CT) model with saturation effects and transient behavior is presented. The model is used for the purpose of analysis and design of power system protection algorithms. Three major classes of protection CT have been modeled which all take into account the nonlinear inductance with remanence effects. The transient short-circuit currents in power systems are simulated under CT saturation condition. The response of a common power system protection algorithm with respect to robustness to nominal parameter variations and sensitivity against maloperation is demonstrated by simulation studies.

  11. Current transformer model with hysteresis for improving the protection response in electrical transmission systems

    International Nuclear Information System (INIS)

    Matussek, Robert; Dzienis, Cezary; Blumschein, Jörg; Schulte, Horst

    2014-01-01

    In this paper, a generic enhanced protection current transformer (CT) model with saturation effects and transient behavior is presented. The model is used for the purpose of analysis and design of power system protection algorithms. Three major classes of protection CT have been modeled which all take into account the nonlinear inductance with remanence effects. The transient short-circuit currents in power systems are simulated under CT saturation condition. The response of a common power system protection algorithm with respect to robustness to nominal parameter variations and sensitivity against maloperation is demonstrated by simulation studies

  12. Hyper-Transcranial Alternating Current Stimulation: Experimental Manipulation of Inter-Brain Synchrony

    Directory of Open Access Journals (Sweden)

    Caroline Szymanski

    2017-11-01

    Full Text Available We walk together, we watch together, we win together: Interpersonally coordinated actions are omnipresent in everyday life, yet the associated neural mechanisms are not well understood. Available evidence suggests that the synchronization of oscillatory activity across brains may provide a mechanism for the temporal alignment of actions between two or more individuals. In an attempt to provide a direct test of this hypothesis, we applied transcranial alternating current stimulation simultaneously to two individuals (hyper-tACS who were asked to drum in synchrony at a set pace. Thirty-eight female-female dyads performed the dyadic drumming in the course of 3 weeks under three different hyper-tACS stimulation conditions: same-phase-same-frequency; different-phase-different-frequency; sham. Based on available evidence and theoretical considerations, stimulation was applied over right frontal and parietal sites in the theta frequency range. We predicted that same-phase-same-frequency stimulation would improve interpersonal action coordination, expressed as the degree of synchrony in dyadic drumming, relative to the other two conditions. Contrary to expectations, both the same-phase-same-frequency and the different-phase-different-frequency conditions were associated with greater dyadic drumming asynchrony relative to the sham condition. No influence of hyper-tACS on behavioral performance was seen when participants were asked to drum separately in synchrony to a metronome. Individual and dyad preferred drumming tempo was also unaffected by hyper-tACS. We discuss limitations of the present version of the hyper-tACS paradigm, and suggest avenues for future research.

  13. Temporary persistence of conduction block after prolonged kilohertz frequency alternating current on rat sciatic nerve

    Science.gov (United States)

    Bhadra, Narendra; Foldes, Emily; Vrabec, Tina; Kilgore, Kevin; Bhadra, Niloy

    2018-02-01

    Objective. Application of kilohertz frequency alternating current (KHFAC) waveforms can result in nerve conduction block that is induced in less than a second. Conduction recovers within seconds when KHFAC is applied for about 5-10 min. This study investigated the effect of repeated and prolonged application of KHFAC on rat sciatic nerve with bipolar platinum electrodes. Approach. Varying durations of KHFAC at signal amplitudes for conduction block with intervals of no stimulus were studied. Nerve conduction was monitored by recording peak Gastrocnemius muscle force utilizing stimulation electrodes proximal (PS) and distal (DS) to a blocking electrode. The PS signal traveled through the block zone on the nerve, while the DS went directly to the motor end-plate junction. The PS/DS force ratio provided a measure of conduction patency of the nerve in the block zone. Main results. Conduction recovery times were found to be significantly affected by the cumulative duration of KHFAC application. Peak stimulated muscle force returned to pre-block levels immediately after cessation of KHFAC delivery when it was applied for less than about 15 min. They fell significantly but recovered to near pre-block levels for cumulative stimulus of 50  ±  20 min, for the tested On/Off times and frequencies. Conduction recovered in two phases, an initial fast one (60-80% recovery), followed by a slower phase. No permanent conduction block was seen at the end of the observation period during any experiment. Significance. This carry-over block effect may be exploited to provide continuous conduction block in peripheral nerves without continuous application of KHFAC.

  14. Hyper-Transcranial Alternating Current Stimulation: Experimental Manipulation of Inter-Brain Synchrony.

    Science.gov (United States)

    Szymanski, Caroline; Müller, Viktor; Brick, Timothy R; von Oertzen, Timo; Lindenberger, Ulman

    2017-01-01

    We walk together, we watch together, we win together: Interpersonally coordinated actions are omnipresent in everyday life, yet the associated neural mechanisms are not well understood. Available evidence suggests that the synchronization of oscillatory activity across brains may provide a mechanism for the temporal alignment of actions between two or more individuals. In an attempt to provide a direct test of this hypothesis, we applied transcranial alternating current stimulation simultaneously to two individuals (hyper-tACS) who were asked to drum in synchrony at a set pace. Thirty-eight female-female dyads performed the dyadic drumming in the course of 3 weeks under three different hyper-tACS stimulation conditions: same-phase-same-frequency; different-phase-different-frequency; sham. Based on available evidence and theoretical considerations, stimulation was applied over right frontal and parietal sites in the theta frequency range. We predicted that same-phase-same-frequency stimulation would improve interpersonal action coordination, expressed as the degree of synchrony in dyadic drumming, relative to the other two conditions. Contrary to expectations, both the same-phase-same-frequency and the different-phase-different-frequency conditions were associated with greater dyadic drumming asynchrony relative to the sham condition. No influence of hyper-tACS on behavioral performance was seen when participants were asked to drum separately in synchrony to a metronome. Individual and dyad preferred drumming tempo was also unaffected by hyper-tACS. We discuss limitations of the present version of the hyper-tACS paradigm, and suggest avenues for future research.

  15. Control of the dielectric microrods rotation in liquid by alternating current electric field

    Science.gov (United States)

    Ren, Yukun; Li, Bin; Jiang, Hongyuan

    2014-05-01

    Microfluidics is a promising system for the manipulation of micro-nano particles and fluids. In this platform, alternating current (AC) electric field is usual an effective tool for the general particles control. However, traditional work paid more attention on the regular spherical particles with no obvious distinction when rotating, resulting in imprecise rotation speed calculation. In essence, non-spherical especially biocompatible particles are not only important for biology application but also significant for obtaining accurate rotating results. Hence, in this paper, SU-8, one of the most biocompatible materials was selected as the manipulation object. AC electric field is employed to rotate SU-8 microrods, in order to obtain a controllable rotation angle for both the accurate experimental results and biosensor applications. Firstly, Clausius-Mossotti(CM) factors frequency spectra with different surface conductance and medium conductivities are presented, thereby the theoretical formula is carried out, including both the torque and rotation velocity expressions of SU-8 microrods. Moreover, simulations for the electric field distribution are developed, indicating the rotating direction. Secondly, the quadrupole electrodes are used to generate rotating electric field, and the electrorotation of SU-8 microrods in different medium is carried out, showing that the particles rotate in the opposite direction of the electric field, meanwhile, the peak frequency increases with the conductivity increases. Finally, the experimental results are discussed and compared with theoretical analysis, and the comparison result shows that they have a good agreement. This work proposes an effective and controllable method to rotate microrods, showing extend application potentials in microelectronics and biosensors.

  16. Modulation of Somatosensory Alpha Rhythm by Transcranial Alternating Current Stimulation at Mu-Frequency

    Directory of Open Access Journals (Sweden)

    Christopher Gundlach

    2017-08-01

    Full Text Available Introduction: Transcranial alternating current stimulation (tACS is emerging as an interventional tool to modulate different functions of the brain, potentially by interacting with intrinsic ongoing neuronal oscillations. Functionally different intrinsic alpha oscillations are found throughout the cortex. Yet it remains unclear whether tACS is capable of specifically modulating the somatosensory mu-rhythm in amplitude.Objectives: We used tACS to modulate mu-alpha oscillations in amplitude. When compared to sham stimulation we expected a modulation of mu-alpha oscillations but not visual alpha oscillations by tACS.Methods: Individual mu-alpha frequencies were determined in 25 participants. Subsequently, blocks of tACS with individual mu-alpha frequency and sham stimulation were applied over primary somatosensory cortex (SI. Electroencephalogram (EEG was recorded before and after either stimulation or sham. Modulations of mu-alpha and, for control, visual alpha amplitudes were then compared between tACS and sham.Results: Somatosensory mu-alpha oscillations decreased in amplitude after tACS was applied at participants’ individual mu-alpha frequency. No changes in amplitude were observed for sham stimulation. Furthermore, visual alpha oscillations were not affected by tACS or sham, respectively.Conclusion: Our results demonstrate the capability of tACS to specifically modulate the targeted somatosensory mu-rhythm when the tACS frequency is tuned to the individual endogenous rhythm and applied over somatosensory areas. Our results are in contrast to previously reported amplitude increases of visual alpha oscillations induced by tACS applied over visual cortex. Our results may point to a specific interaction between our stimulation protocol and the functional architecture of the somatosensory system.

  17. Development of alternating current circuit simulation as essential learning support for senior high school student

    Directory of Open Access Journals (Sweden)

    Mayang Dwinta Trisniarti

    2017-02-01

    Full Text Available In this study an interactive simulation of Alternating Current circuit was developed by using Articulate Storyline 2 and Adobe Flash CS 6 programs. The aim of this study was providing a computer interactive simulation as essential learning support for Senior High School student. One of the most important features of AC circuit simulation is the easily and continuous material to attain learning objectivity and interest toward students. This AC circuit simulation is built to create real-time sine wave graphs so that student could compare the result if the variable were changed gradually. The validation is held through several experts and reviewers due to get obtained through questionnaires. The results of this research could be concluded that AC circuit simulation for Senior High School Physics have good criteria based on user interface, i.e. 50% of respondents rated enough, 16.67% of respondents rated good, and 33.33% of respondents rated very good. Based on maintenance, i.e. 50% of respondents rated enough, 20% of respondents rated good, and 30% of respondents rated very good. Then based on usability, i.e. 6.67% of respondents rated good and 93.33% rated very good. Furthermore, based on understanding, i.e. 6.67% of respondents rated enough, 30% of respondents rated good, and 73.33% of respondents rated very good. The use of AC circuit simulation could improve the senior high school students’ cognitive ability on the Physics’s course, i.e. with the average score increased from 68.67 to 80.5 based on 30 students.

  18. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry

    International Nuclear Information System (INIS)

    Guerreiro, Gabriela V.; Zaitouna, Anita J.; Lai, Rebecca Y.

    2014-01-01

    Graphical abstract: -- Highlights: •An electrochemical Hg(II) sensor based on T–Hg(II)–T sensing motif was fabricated. •A methylene blue-modified DNA probe was used to fabricate the sensor. •Sensor performance was evaluated using ACV, CV, SWV, and DPV. •The sensor behaves as a “signal-off” sensor in ACV and CV. •The sensor behaves as either a “signal-on” or “signal-off” sensor in SWV and DPV. -- Abstract: Here we report the characterization of an electrochemical mercury (Hg 2+ ) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg 2+ rather rapidly; majority of the signal change occurred in 2+ , which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors

  19. Identification of a current hot spot of HIV type 1 transmission in Mongolia by molecular epidemiological analysis.

    Science.gov (United States)

    Davaalkham, Jagdagsuren; Unenchimeg, Puntsag; Baigalmaa, Chultem; Erdenetuya, Gombo; Nyamkhuu, Dulmaa; Shiino, Teiichiro; Tsuchiya, Kiyoto; Hayashida, Tsunefusa; Gatanaga, Hiroyuki; Oka, Shinichi

    2011-10-01

    We investigated the current molecular epidemiological status of HIV-1 in Mongolia, a country with very low incidence of HIV-1 though with rapid expansion in recent years. HIV-1 pol (1065 nt) and env (447 nt) genes were sequenced to construct phylogenetic trees. The evolutionary rates, molecular clock phylogenies, and other evolutionary parameters were estimated from heterochronous genomic sequences of HIV-1 subtype B by the Bayesian Markov chain Monte Carlo method. We obtained 41 sera from 56 reported HIV-1-positive cases as of May 2009. The main route of infection was men who have sex with men (MSM). Dominant subtypes were subtype B in 32 cases (78%) followed by subtype CRF02_AG (9.8%). The phylogenetic analysis of the pol gene identified two clusters in subtype B sequences. Cluster 1 consisted of 21 cases including MSM and other routes of infection, and cluster 2 consisted of eight MSM cases. The tree analyses demonstrated very short branch lengths in cluster 1, suggesting a surprisingly active expansion of HIV-1 transmission during a short period with the same ancestor virus. Evolutionary analysis indicated that the outbreak started around the early 2000s. This study identified a current hot spot of HIV-1 transmission and potential seed of the epidemic in Mongolia. Comprehensive preventive measures targeting this group are urgently needed.

  20. Risk factors for secondary transmission of Shigella infection within households: implications for current prevention policy

    Directory of Open Access Journals (Sweden)

    Boveé Lian

    2012-12-01

    Full Text Available Abstract Background Internationally, guidelines to prevent secondary transmission of Shigella infection vary widely. Cases, their contacts with diarrhoea, and those in certain occupational groups are frequently excluded from work, school, or daycare. In the Netherlands, all contacts attending pre-school (age 0–3 and junior classes in primary school (age 4–5, irrespective of symptoms, are also excluded pending microbiological clearance. We identified risk factors for secondary Shigella infection (SSI within households and evaluated infection control policy in this regard. Methods This retrospective cohort study of households where a laboratory confirmed Shigella case was reported in Amsterdam (2002–2009 included all households at high risk for SSI (i.e. any household member under 16 years. Cases were classified as primary, co-primary or SSIs. Using univariable and multivariable binomial regression with clustered robust standard errors to account for household clustering, we examined case and contact factors (Shigella serotype, ethnicity, age, sex, household size, symptoms associated with SSI in contacts within households. Results SSI occurred in 25/ 337 contacts (7.4%: 20% were asymptomatic, 68% were female, and median age was 14 years (IQR: 4–38. In a multivariable model adjusted for case and household factors, only diarrhoea in contacts was associated with SSI (IRR 8.0, 95% CI:2.7-23.8. In a second model, factors predictive of SSI in contacts were the age of case (0–3 years (IRRcase≥6 years:2.5, 95% CI:1.1-5.5 and 4–5 years (IRRcase≥6 years:2.2, 95% CI:1.1-4.3 and household size (>6 persons (IRR2-4 persons 3.4, 95% CI:1.2-9.5. Conclusions To identify symptomatic and asymptomatic SSI, faecal screening should be targeted at all household contacts of preschool cases (0–3 years and cases attending junior class in primary school (4–5 years and any household contact with diarrhoea. If screening was limited to these groups, only

  1. Reliability of emergency alternating-current power systems at nuclear power plants: a discussion of NUREG/CR-2989

    International Nuclear Information System (INIS)

    Battle, R.E.

    1985-01-01

    The reliability of emergency alternating-current power systems typical of most nuclear power plants was estimated by using fault-tree analysis of selected typical designs. The failure probabilities used in the fault trees were calculated from extensive historical data collected from Licensee Event Reports and from operating experience information obtained from nuclear plant licensees. Trends of diesel generator independent failure on demand are included. No one or two improvements can be made at all plants to increase significantly the industry-average emergency alternating-current power system reliability; the most beneficial improvements are varied and plant specific

  2. Energy transmission transformer for a wireless capsule endoscope: analysis of specific absorption rate and current density in biological tissue.

    Science.gov (United States)

    Shiba, Kenji; Nagato, Tomohiro; Tsuji, Toshio; Koshiji, Kohji

    2008-07-01

    This paper reports on the electromagnetic influences on the analysis of biological tissue surrounding a prototype energy transmission system for a wireless capsule endoscope. Specific absorption rate (SAR) and current density were analyzed by electromagnetic simulator in a model consisting of primary coil and a human trunk including the skin, fat, muscle, small intestine, backbone, and blood. First, electric and magnetic strength in the same conditions as the analytical model were measured and compared to the analytical values to confirm the validity of the analysis. Then, SAR and current density as a function of frequency and output power were analyzed. The validity of the analysis was confirmed by comparing the analytical values with the measured ones. The SAR was below the basic restrictions of the International Commission on Nonionizing Radiation Protection (ICNIRP). At the same time, the results for current density show that the influence on biological tissue was lowest in the 300-400 kHz range, indicating that it was possible to transmit energy safely up to 160 mW. In addition, we confirmed that the current density has decreased by reducing the primary coil's current.

  3. Experimental study on magnetically insulated transmission line electrode surface evolution process under MA/cm current density

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, PengFei; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China); State Key Laboratory of Intense Pulse Radiation of Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Hu, Yang; Yang, HaiLiang; Sun, Jiang; Wang, Liangping; Cong, Peitian [State Key Laboratory of Intense Pulse Radiation of Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China)

    2016-03-15

    The design of high-current density magnetically insulated transmission line (MITL) is a difficult problem of current large-scale Z-pinch device. In particular, a thorough understanding of the MITL electrode surface evolution process under high current density is lacking. On the “QiangGuang-I” accelerator, the load area possesses a low inductance short-circuit structure with a diameter of 2.85 mm at the cathode, and three reflux columns with a diameter of 3 mm and uniformly distributed circumference at the anode. The length of the high density MITL area is 20 mm. A laser interferometer is used to assess and analyze the state of the MITL cathode and anode gap, and their evolution process under high current density. Experimental results indicate that evident current loss is not observed in the current density area at pulse leading edge, and peak when the surface current density reaches MA/cm. Analysis on electrode surface working conditions indicates that when the current leading edge is at 71.5% of the peak, the total evaporation of MITL cathode structure can be realized by energy deposition caused by ohmic heating. The electrode state changes, and diffusion conditions are reflected in the laser interferometer image. The MITL cathode area mainly exists in metal vapor form. The metal vapor density in the cathode central region is higher than the upper limit of laser penetration density (∼4 × 10{sup 21}/cm{sup 3}), with an expansion velocity of ∼0.96 km/s. The metal vapor density in the electrode outer area may lead to evident distortion of fringes, and its expansion velocity is faster than that in the center area (1.53 km/s).

  4. Development and Testing of a Transmission Voltage SuperLimiter™ Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Romanosky, Walter [American Superconductor Corporation, Devens, MA (United States)

    2012-09-01

    This report summarizes work by American Superconductor (AMSC), Los Alamos National Laboratory (LANL), Nexans, Siemens and Southern California Edison on a 138kV resistive type high temperature superconductor (HTS) fault current limiter (FCL) under a cooperative agreement with the U.S. Department of Energy (DOE). Phase 1A encompassed core technology development and system design and was previously reported (see summary that follows in Section 1.1 of the Introduction). This report primarily discusses work performed during Phase 1B, and addresses the fabrication and test of a single-phase prototype FCL. The results are presented along with a discussion of requirements/specifications and lessons learned to aid future development and product commercialization.

  5. Alternating current impedance spectroscopic analysis of biofunctionalized vertically-aligned silica nanospring surface for biosensor applications

    Science.gov (United States)

    Timalsina, Yukta P.

    In this dissertation, a process of vertically-aligned (silica) nanosprings (VANS) based biosensor development is presented. Alternating current (AC) impedance spectroscopy has been used to analyze sensor response as a function of saline phosphate (SP) buffer and biological solutions. The sensor is a parallel plate capacitor consisting of two glass substrates coated with indium tin oxide (ITO), where the VANS [or randomly-aligned nanosprings (RANS)] grown on one substrate serve as the dielectric spacer layer. The response of a VANS device as a function of ionic concentration in SP buffer was examined and an equivalent circuit model was developed. The results demonstrated that VANS sensors exhibited greater sensitivity to the changes in SP concentration relative to the ITO sensors, which serve as controls. The biofunctionalized VANS surface via physisorption and the cross-linker method demonstrates the repeatability, specificity, and selectivity of the binding. The physisorption of biotinylated immunoglobulin G (B-IgG) onto the VANS surface simplifies the whole sensing procedure for the detection of glucose oxidase, since the avidin-conjugated glucose oxidase (Av-GOx) can directly be immobilized on the B-IgG. The cross linker method involves the covalent attachment of antibodies onto the functionalized VANS surface via imine bond. The experiments revealed that the VANS sensor response is solely the result of the interaction of target molecule i.e. mouse IgG with the probe layer, i.e. goat antimouse IgG (GalphaM IgG). It was determined that VANS-based sensors exhibit a greater magnitude of change between successive bio-layers relative to the controls above 100 Hz, which indicates that the addition of biomolecules inhibits the diffusion of ions and changes the effective dielectric response of the VANS via biomolecular polarization. The study of ionic transport in nanosprings suggested that conductance follows a scaling law. It was demonstrated that a VANS-based device

  6. Characterization of an electrochemical mercury sensor using alternating current, cyclic, square wave and differential pulse voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Guerreiro, Gabriela V.; Zaitouna, Anita J.; Lai, Rebecca Y., E-mail: rlai2@unl.edu

    2014-01-31

    Graphical abstract: -- Highlights: •An electrochemical Hg(II) sensor based on T–Hg(II)–T sensing motif was fabricated. •A methylene blue-modified DNA probe was used to fabricate the sensor. •Sensor performance was evaluated using ACV, CV, SWV, and DPV. •The sensor behaves as a “signal-off” sensor in ACV and CV. •The sensor behaves as either a “signal-on” or “signal-off” sensor in SWV and DPV. -- Abstract: Here we report the characterization of an electrochemical mercury (Hg{sup 2+}) sensor constructed with a methylene blue (MB)-modified and thymine-containing linear DNA probe. Similar to the linear probe electrochemical DNA sensor, the resultant sensor behaved as a “signal-off” sensor in alternating current voltammetry and cyclic voltammetry. However, depending on the applied frequency or pulse width, the sensor can behave as either a “signal-off” or “signal-on” sensor in square wave voltammetry (SWV) and differential pulse voltammetry (DPV). In SWV, the sensor showed “signal-on” behavior at low frequencies and “signal-off” behavior at high frequencies. In DPV, the sensor showed “signal-off” behavior at short pulse widths and “signal-on” behavior at long pulse widths. Independent of the sensor interrogation technique, the limit of detection was found to be 10 nM, with a linear dynamic range between 10 nM and 500 nM. In addition, the sensor responded to Hg{sup 2+} rather rapidly; majority of the signal change occurred in <20 min. Overall, the sensor retains all the characteristics of this class of sensors; it is reagentless, reusable, sensitive, specific and selective. This study also highlights the feasibility of using a MB-modified probe for real-time sensing of Hg{sup 2+}, which has not been previously reported. More importantly, the observed “switching” behavior in SWV and DPV is potentially generalizable and should be applicable to most sensors in this class of dynamics-based electrochemical biosensors.

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

    OpenAIRE

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

    2015-01-01

    Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of s...

  8. Modeling Geoelectric Fields and Geomagnetically Induced Currents Around New Zealand to Explore GIC in the South Island's Electrical Transmission Network

    Science.gov (United States)

    Divett, T.; Ingham, M.; Beggan, C. D.; Richardson, G. S.; Rodger, C. J.; Thomson, A. W. P.; Dalzell, M.

    2017-10-01

    Transformers in New Zealand's South Island electrical transmission network have been impacted by geomagnetically induced currents (GIC) during geomagnetic storms. We explore the impact of GIC on this network by developing a thin-sheet conductance (TSC) model for the region, a geoelectric field model, and a GIC network model. (The TSC is composed of a thin-sheet conductance map with underlying layered resistivity structure.) Using modeling approaches that have been successfully used in the United Kingdom and Ireland, we applied a thin-sheet model to calculate the electric field as a function of magnetic field and ground conductance. We developed a TSC model based on magnetotelluric surveys, geology, and bathymetry, modified to account for offshore sediments. Using this representation, the thin sheet model gave good agreement with measured impedance vectors. Driven by a spatially uniform magnetic field variation, the thin-sheet model results in electric fields dominated by the ocean-land boundary with effects due to the deep ocean and steep terrain. There is a strong tendency for the electric field to align northwest-southeast, irrespective of the direction of the magnetic field. Applying this electric field to a GIC network model, we show that modeled GIC are dominated by northwest-southeast transmission lines rather than east-west lines usually assumed to dominate.

  9. Method and system for a gas tube switch-based voltage source high voltage direct current transmission system

    Science.gov (United States)

    She, Xu; Chokhawala, Rahul Shantilal; Zhou, Rui; Zhang, Di; Sommerer, Timothy John; Bray, James William

    2016-12-13

    A voltage source converter based high-voltage direct-current (HVDC) transmission system includes a voltage source converter (VSC)-based power converter channel. The VSC-based power converter channel includes an AC-DC converter and a DC-AC inverter electrically coupled to the AC-DC converter. The AC-DC converter and a DC-AC inverter include at least one gas tube switching device coupled in electrical anti-parallel with a respective gas tube diode. The VSC-based power converter channel includes a commutating circuit communicatively coupled to one or more of the at least one gas tube switching devices. The commutating circuit is configured to "switch on" a respective one of the one or more gas tube switching devices during a first portion of an operational cycle and "switch off" the respective one of the one or more gas tube switching devices during a second portion of the operational cycle.

  10. Determination of complex formation constants by phase sensitive alternating current polarography: Cadmium-polymethacrylic acid and cadmium-polygalacturonic acid.

    Science.gov (United States)

    Garrigosa, Anna Maria; Gusmão, Rui; Ariño, Cristina; Díaz-Cruz, José Manuel; Esteban, Miquel

    2007-10-15

    The use of phase sensitive alternating current polarography (ACP) for the evaluation of complex formation constants of systems where electrodic adsorption is present has been proposed. The applicability of the technique implies the previous selection of the phase angle where contribution of capacitive current is minimized. This is made using Multivariate Curve Resolution by Alternating Least Squares (MCR-ALS) in the analysis of ACP measurements at different phase angles. The method is checked by the study of the complexation of Cd by polymethacrylic (PMA) and polygalacturonic (PGA) acids, and the optimal phase angles have been ca. -10 degrees for Cd-PMA and ca. -15 degrees for Cd-PGA systems. The goodness of phase sensitive ACP has been demonstrated comparing the determined complex formation constants with those obtained by reverse pulse polarography, a technique that minimizes the electrode adsorption effects on the measured currents.

  11. Including alternative resources in state renewable portfolio standards: Current design and implementation experience

    International Nuclear Information System (INIS)

    Heeter, Jenny; Bird, Lori

    2013-01-01

    As of October 2012, 29 states, the District of Columbia, and Puerto Rico have instituted a renewable portfolio standard (RPS). Each state policy is unique, varying in percentage targets, timetables, and eligible resources. Increasingly, new RPS polices have included alternative resources. Alternative resources have included energy efficiency, thermal resources, and, to a lesser extent, non-renewables. This paper examines state experience with implementing renewable portfolio standards that include energy efficiency, thermal resources, and non-renewable energy and explores compliance experience, costs, and how states evaluate, measure, and verify energy efficiency and convert thermal energy. It aims to gain insights from the experience of states for possible federal clean energy policy as well as to share experience and lessons for state RPS implementation. - Highlights: • Increasingly, new RPS policies have included alternative resources. • Nearly all states provide a separate tier or cap on the quantity of eligible alternative resources. • Where allowed, non-renewables and energy efficiency are being heavily utilized

  12. Complementary and Alternative Medicine in Rural Communities: Current Research and Future Directions

    Science.gov (United States)

    Wardle, Jon; Lui, Chi-Wai; Adams, Jon

    2012-01-01

    Contexts: The consumption of complementary and alternative medicine (CAM) in rural areas is a significant contemporary health care issue. An understanding of CAM use in rural health can provide a new perspective on health beliefs and practice as well as on some of the core service delivery issues facing rural health care generally. Purpose: This…

  13. The impact of current alternative herbal remedies on dental patient management.

    Science.gov (United States)

    Karimi, K

    1999-01-01

    With the recent boom in holistic and herbal medicine and an ever-growing trend among the general population to refer to herbal remedies as an alternative to traditional pharmaceutical therapies, dental health care providers must be aware of the wide consumption of such products and understand their nature. It becomes imperative, therefore, to include questions regarding the use of herbal preparations as a matter of routine in the patient's drug history, since this may impact a safe dental patient care delivery.

  14. Comparison of two alternative sequences for human in-vivo brain MR Current Density Imaging (MRCDI)

    DEFF Research Database (Denmark)

    Göksu, Cihan; Hanson, Lars G.; Siebner, Hartwig

    ) and steady-state free precession free induction decay (SSFP-FID), with single- vs. multi-gradient-echo readouts. We demonstrate that multi-gradient-echo readouts improve both methods. We validate the linear dependence of the measured current-induced magnetic eld on the injected current strength for both...

  15. Alternating current loss reduction for rectangular busbars by covering their edges with low permeable magnetic caps

    Energy Technology Data Exchange (ETDEWEB)

    Sasada, Ichiro, E-mail: sasada@ence.kyushu-u.ac.jp [Applied Science for Electronics and Materials, Kyushu University, Kasuga (Japan)

    2014-05-07

    A method to reduce ac conductive losses in a thin rectangular busbar made of copper is presented. The method is based on a technique, which makes the distribution of the ac current in the cross section of a busbar flatter. Edges of a thin busbar are covered with low permeability magnetic thin layers as caps. The magnetic cap makes the impedance experienced by the current flowing near the edge comparatively larger so that currents cannot get crowded near the edges of a busbar. This method is numerically verified.

  16. Alternating current for the West; Un courant alternatif pour le grand ouest

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    In the framework of the reactor EPR construction in the Manche, the authors wonder on the pertinence of this energy choice for the economy and the environment of the West France. They show that there is an alternative to this choice. In a first part a state of the situation concerning the electricity supply and demand in the region is detailed. Then from the local potential of renewable electric power production and the electricity conservation, they propose many concrete actions. (A.L.B.)

  17. Overview of Alternative Bunching and Current-shaping Techniques for Low-Energy Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Piot, Philippe [Northern Illinois U.

    2015-12-01

    Techniques to bunch or shape an electron beam at low energies (E <15 MeV) have important implications toward the realization of table-top radiation sources [1] or to the design of compact multi-user free-electron lasers[2]. This paper provides an overview of alternative methods recently developed including techniques such as wakefield-based bunching, space-charge-driven microbunching via wave-breaking [3], ab-initio shaping of the electron-emission process [4], and phase space exchangers. Practical applications of some of these methods to foreseen free-electron-laser configurations are also briefly discussed [5].

  18. Why Current Statistics of Complementary Alternative Medicine Clinical Trials is Invalid.

    Science.gov (United States)

    Pandolfi, Maurizio; Carreras, Giulia

    2018-06-07

    It is not sufficiently known that frequentist statistics cannot provide direct information on the probability that the research hypothesis tested is correct. The error resulting from this misunderstanding is compounded when the hypotheses under scrutiny have precarious scientific bases, which, generally, those of complementary alternative medicine (CAM) are. In such cases, it is mandatory to use inferential statistics, considering the prior probability that the hypothesis tested is true, such as the Bayesian statistics. The authors show that, under such circumstances, no real statistical significance can be achieved in CAM clinical trials. In this respect, CAM trials involving human material are also hardly defensible from an ethical viewpoint.

  19. Singularities of construction of static war-hour meters alternating-current

    Directory of Open Access Journals (Sweden)

    М.О. Петрище

    2004-04-01

    Full Text Available  The analysis of construction of static war-hour meters is carried out which are founded on use of specialized tools, which are intended for measurement of a active energy. The shortages of such methods concerning a possibility of unauthorized takeoff of an electric energy are marked through improper phasing of a current. The method is offered which allows to construct static war-hour meters insensitive to improper phasing of a current.

  20. Alternative model of space-charge-limited thermionic current flow through a plasma

    Science.gov (United States)

    Campanell, M. D.

    2018-04-01

    It is widely assumed that thermionic current flow through a plasma is limited by a "space-charge-limited" (SCL) cathode sheath that consumes the hot cathode's negative bias and accelerates upstream ions into the cathode. Here, we formulate a fundamentally different current-limited mode. In the "inverse" mode, the potentials of both electrodes are above the plasma potential, so that the plasma ions are confined. The bias is consumed by the anode sheath. There is no potential gradient in the neutral plasma region from resistivity or presheath. The inverse cathode sheath pulls some thermoelectrons back to the cathode, thereby limiting the circuit current. Thermoelectrons entering the zero-field plasma region that undergo collisions may also be sent back to the cathode, further attenuating the circuit current. In planar geometry, the plasma density is shown to vary linearly across the electrode gap. A continuum kinetic planar plasma diode simulation model is set up to compare the properties of current modes with classical, conventional SCL, and inverse cathode sheaths. SCL modes can exist only if charge-exchange collisions are turned off in the potential well of the virtual cathode to prevent ion trapping. With the collisions, the current-limited equilibrium must be inverse. Inverse operating modes should therefore be present or possible in many plasma devices that rely on hot cathodes. Evidence from past experiments is discussed. The inverse mode may offer opportunities to minimize sputtering and power consumption that were not previously explored due to the common assumption of SCL sheaths.

  1. Practical aspects of the use of three-phase alternating current electric machines in electricity storage system

    Science.gov (United States)

    Ciucur, Violeta

    2015-02-01

    Of three-phase alternating current electric machines, it brings into question which of them is more advantageous to be used in electrical energy storage system by pumping water. The two major categories among which are given dispute are synchronous and the asynchronous machine. To consider the synchronous machine with permanent magnet configuration because it brings advantages compared with conventional synchronous machine, first by removing the necessary additional excitation winding. From the point of view of loss of the two types of machines, the optimal adjustment of the magnetic flux density is obtained to minimize the copper loss by hysteresis and eddy currents.

  2. An alternative explanation for the occurrence of short circuit current increases in the small intestine following challenge by bacterial enterotoxins.

    Science.gov (United States)

    Lucas, M L

    2013-10-01

    Secretory diarrhoeal disease due to enterotoxins is thought to arise from the enhancement to pathologically high rates of normally occurring chloride ion and therefore fluid secretion from enterocytes. In support of this concept, many enterotoxins increase intestinal short-circuit current, regarded now as faithfully reflecting the increased chloride ion secretion. Contradicting this assumption, STa reduces absorption but does not cause secretion in vivo although short-circuit current is increased in vitro. There is therefore a mismatch between an assumed enterocyte mediated secretory event that should but does not cause net fluid secretion and an undoubtedly increased short-circuit current. It is proposed here that short-circuit current increases are not themselves secretory events but result from interrupted fluid absorption. A noteworthy feature of compounds that inhibit the increase in short-circuit current is that the majority are vasoactive, neuroactive or both. In general, vasodilator substances increase current. An alternative hypothesis for the origin of short-circuit current increases is that these result from reflex induction of electrogenic fluid absorption. This reflex enhances a compensatory response that is also present at a cellular level. An intestinal reflex is therefore proposed by which decreases in interstitial and intravascular volume or pressure within the intestine initiate an electrogenic fluid absorption mechanism that compensates for the loss of electrically neutral fluid absorption. This hypothesis would explain the apparently complex pharmacology of short-circuit current increases since many depressor substances have receptors in common with enterocytes and enteric nerves. The proposed alternative view of the origin of short-circuit current increases assumes that these do not represent chloride secretion from the enterocytes. This view may therefore aid the successful development of anti-diarrhoeal drugs to overcome a major cause of

  3. Electricity Transmission, Pipelines, and National Trails: An Analysis of Current and Potential Intersections on Federal Lands in the Eastern United States, Alaska, and Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Kuiper, James A. [Argonne National Lab. (ANL), Argonne, IL (United States); Krummel, John R. [Argonne National Lab. (ANL), Argonne, IL (United States); Hlava, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States); Moore, H. Robert [Argonne National Lab. (ANL), Argonne, IL (United States); Orr, Andrew B. [Argonne National Lab. (ANL), Argonne, IL (United States); Schlueter, Scott O. [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, Robert G. [Argonne National Lab. (ANL), Argonne, IL (United States); Zvolanek, Emily A. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-11-21

    As has been noted in many reports and publications, acquiring new or expanded rights-of-way for transmission is a challenging process, because numerous land use and land ownership constraints must be overcome to develop pathways suitable for energy transmission infrastructure. In the eastern U.S., more than twenty federally protected national trails (some of which are thousands of miles long, and cross many states) pose a potential obstacle to the development of new or expanded electricity transmission capacity. However, the scope of this potential problem is not well-documented, and there is no baseline information available that could allow all stakeholders to study routing scenarios that could mitigate impacts on national trails. This report, Electricity Transmission, Pipelines, and National Trails: An Analysis of Current and Potential Intersections on Federal Lands in the Eastern United States, was prepared by the Environmental Science Division of Argonne National Laboratory (Argonne). Argonne was tasked by DOE to analyze the “footprint” of the current network of National Historic and Scenic Trails and the electricity transmission system in the 37 eastern contiguous states, Alaska, and Hawaii; assess the extent to which national trails are affected by electrical transmission; and investigate the extent to which national trails and other sensitive land use types may be affected in the near future by planned transmission lines. Pipelines are secondary to transmission lines for analysis, but are also within the analysis scope in connection with the overall directives of Section 368 of the Energy Policy Act of 2005, and because of the potential for electrical transmission lines being collocated with pipelines.

  4. Assessing the Liquidity of Firms: Robust Neural Network Regression as an Alternative to the Current Ratio

    Science.gov (United States)

    de Andrés, Javier; Landajo, Manuel; Lorca, Pedro; Labra, Jose; Ordóñez, Patricia

    Artificial neural networks have proven to be useful tools for solving financial analysis problems such as financial distress prediction and audit risk assessment. In this paper we focus on the performance of robust (least absolute deviation-based) neural networks on measuring liquidity of firms. The problem of learning the bivariate relationship between the components (namely, current liabilities and current assets) of the so-called current ratio is analyzed, and the predictive performance of several modelling paradigms (namely, linear and log-linear regressions, classical ratios and neural networks) is compared. An empirical analysis is conducted on a representative data base from the Spanish economy. Results indicate that classical ratio models are largely inadequate as a realistic description of the studied relationship, especially when used for predictive purposes. In a number of cases, especially when the analyzed firms are microenterprises, the linear specification is improved by considering the flexible non-linear structures provided by neural networks.

  5. Influence of direct and alternating current electric fields on efficiency promotion and leaching risk alleviation of chelator assisted phytoremediation.

    Science.gov (United States)

    Luo, Jie; Cai, Limei; Qi, Shihua; Wu, Jian; Sophie Gu, Xiaowen

    2018-03-01

    Direct and alternating current electric fields with various voltages were used to improve the decontamination efficiency of chelator assisted phytoremediation for multi-metal polluted soil. The alleviation effect of electric field on leaching risk caused by chelator application during phytoremediation process was also evaluated. Biomass yield, pollutant uptake and metal leaching retardation under alternating current (AC) and direct current (DC) electric fields were compared. The biomass yield of Eucalyptus globulus under AC fields with various voltages (2, 4 and 10 V) were 3.91, 4.16 and 3.67kg, respectively, significantly higher than the chelator treatment without electric field (2.71kg). Besides growth stimulation, AC fields increased the metal concentrations of plant tissues especially in aerial parts manifested by the raised translocation factor of different metals. Direct current electric fields with low and moderate voltages increased the biomass production of the species to 3.45 and 3.12kg, respectively, while high voltage on the contrary suppressed the growth of the plants (2.66kg). Under DC fields, metal concentrations elevated obviously with increasing voltages and the metal translocation factors were similar under all voltages. Metal extraction per plant achieved the maximum value under moderate voltage due to the greatest biomass production. DC field with high voltage (10V) decreased the volume of leachate from the chelator treatment without electric field from 1224 to 56mL, while the leachate gathered from AC field treatments raised from 512 to 670mL. DC field can retard the downward movement of metals caused by chelator application more effectively relative to AC field due to the constant water flow and electroosmosis direction. Alternating current field had more promotive effect on chelator assisted phytoremediation efficiency than DC field illustrated by more metal accumulation in the species. However, with the consideration of leaching risk, DC

  6. Skills Training for School Leavers: Some Alternative Approaches. Current Issues Brief No. 2.

    Science.gov (United States)

    Fraser, Doug

    In the face of escalating youth unemployment, some new approaches are needed for training out-of-school youth in Australia. The current system of apprenticeship has become outmoded because many of the skilled trades that the system prepares young people for will soon be non-existent. One approach to this problem has been implementation of…

  7. The role of augmentative and alternative communication for children with autism: current status and future trends

    Directory of Open Access Journals (Sweden)

    Iacono T

    2016-09-01

    Full Text Available Teresa Iacono,1 David Trembath,2 Shane Erickson3 1Living with Disability Research Centre, La Trobe University, Bendigo, VIC, Australia; 2Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia; 3Living with Disability Research Centre, La Trobe University, Melbourne, VIC, Australia Background: Augmentative and alternative communication (AAC interventions are used for children with autism, often as stand-alone communication interventions for those who are minimally verbal. Our aim was to synthesize the evidence for AAC interventions for children (up to 21 years, and then consider the role of AAC within established, comprehensive, evidence-based autism interventions targeting learning across multiple developmental domains.Design: We completed a systematic search of three databases (OVID Medline, PsycINFO, ERIC as well as forward citation and hand searches to identify systematic reviews of AAC intervention efficacy research including children with autism, published between 2000 and March 2016 in peer-reviewed journals. Data pertaining to the quality indicators of included studies, effect sizes for intervention outcomes, and evidence for effectiveness were extracted for descriptive analysis.Results: The search yielded 17 systematic reviews. Most provided indicators of research quality for included studies, of which only relatively few provided conclusive results. Communication targets tended to be focused on teaching children to make requests. Still, effect size measures for included studies indicated that AAC was effective to highly effective.Conclusion: There is growing evidence for the potential benefits of AAC for children with autism, but there is a need for more well-designed studies and broader, targeted outcomes. Furthermore, a lack of evidence for the role of AAC within comprehensive intervention programs may account for a tendency by autism researchers and practitioners to neglect this intervention. Attempts to

  8. Our Approach to Toxic Epidermal Necrolysis and Review of Current Treatment Alternatives

    Directory of Open Access Journals (Sweden)

    Fatih Uygur

    2008-09-01

    Full Text Available Toxic epidermal necrolysis (TEN is a clinical entity which has a 30 to 40 % mortality rate, with necrolysis affecting the entire epidermis. Antibiotics, nonsteroidal anti-inflammatory drugs and anticonvulsants are offender drugs in TEN etiology. A standard treatment protocol with proven efficacy is still lacking. In this study, current treatment practice and our treatment strategy for TEN is discussed and eight patients treated in our clinic between the years 2001 and 2008 are reviewed.

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

    Science.gov (United States)

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

    2016-10-01

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

  10. Analysis of current and alternative phenol based RNA extraction methodologies for cyanobacteria

    Directory of Open Access Journals (Sweden)

    Lindblad Peter

    2009-08-01

    Full Text Available Abstract Background The validity and reproducibility of gene expression studies depend on the quality of extracted RNA and the degree of genomic DNA contamination. Cyanobacteria are gram-negative prokaryotes that synthesize chlorophyll a and carry out photosynthetic water oxidation. These organisms possess an extended array of secondary metabolites that impair cell lysis, presenting particular challenges when it comes to nucleic acid isolation. Therefore, we used the NHM5 strain of Nostoc punctiforme ATCC 29133 to compare and improve existing phenol based chemistry and procedures for RNA extraction. Results With this work we identify and explore strategies for improved and lower cost high quality RNA isolation from cyanobacteria. All the methods studied are suitable for RNA isolation and its use for downstream applications. We analyse different Trizol based protocols, introduce procedural changes and describe an alternative RNA extraction solution. Conclusion It was possible to improve purity of isolated RNA by modifying protocol procedures. Further improvements, both in RNA purity and experimental cost, were achieved by using a new extraction solution, PGTX.

  11. The outcomes of complementary and alternative medicine use among pregnant and birthing women: current trends and future directions.

    Science.gov (United States)

    Steel, Amie; Adams, Jon; Sibbritt, David; Broom, Alex

    2015-06-01

    Complementary and alternative medicine is used by a substantial number of pregnant women and maternity care providers are often faced with the task of ensuring women are using safe and effective treatments while respecting a woman's right to autonomous decision-making. In the era of evidence-based medicine maternity health professionals are expected to draw upon the best available evidence when making clinical decisions and providing health advice. This review will outline the current trends in research evidence associated with the outcomes of complementary and alternative medicine use amongst pregnant and birthing women as well as highlight some potential directions for future development in this important yet largely unknown topic in contemporary maternity care.

  12. Regional economic effects of current and proposed management alternatives for Sand Lake National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Lambert, Heather

    2005-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Sand Lake National Wildlife Refuge (NWR), located 27 miles northeast of Aberdeen, South Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Sand Lake NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

  13. Regional economic effects of current and proposed management alternatives for Arrowwood National Wildlife Refuge

    Science.gov (United States)

    Koontz, Lynne; Lambert, Heather

    2005-01-01

    The National Wildlife Refuge System Improvement Act of 1997 requires all units of the National Wildlife Refuge System to be managed under a Comprehensive Conservation Plan (CCP). The CCP must describe the desired future conditions of a Refuge and provide long range guidance and management direction to achieve Refuge purposes. Arrowwood National Wildlife Refuge (NWR), located along the James River in east central North Dakota, is in the process of developing a range of management goals, objectives, and strategies for the CCP. The CCP for Arrowwood NWR must contain an analysis of expected effects associated with current and proposed Refuge management strategies.

  14. Tidal sails : an alternative to turbines for harvesting tidal current energy

    Energy Technology Data Exchange (ETDEWEB)

    Hanssen, J.E. [Tidal Sails, Haugesund (Norway)

    2008-07-01

    Tidal sail technology harnesses the energy of tidal streams in order to produce electricity. Tidal currents move the sails that are attached to wires that rotate generator wheels to produce electricity. The technology has a low impact on the surrounding environment and is simple to install. This presentation discussed the methods used to determine the influence of relative sail velocity and measure estimated energy output levels. The sails were recently tested at an on-grid tidal stream pilot in the Norwegian Arctic. A 300 kW turbine installed at the site demonstrated that the site was suitable for a full-scale development of 20 tripod-mounted 600 kW turbines placed at 50 m depth. It was estimated that the 10 strings of 1000 m length provided between 200 and 250 GWh per year. The sails have also been used at a high speed site in Washington state in the United States. The 25 m pilot plant was installed to verify site suitability and examine sail behaviour in real, high-flow currents. It is expected that the technology will be fully commercialized by 2011. Other pilot tests are being conducted to examine flow behaviour; mooring and flotation functionality; and launch and lift capabilities. Engineering work is ongoing to examine plant designs, variable sail spacing, and collaborations with key component suppliers. tabs., figs.

  15. Electricity Transmission, Pipelines, and National Trails. An Analysis of Current and Potential Intersections on Federal Lands in the Eastern United States, Alaska, and Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Kuiper, James A; Krummel, John R; Hlava, Kevin J; Moore, H Robert; Orr, Andrew B; Schlueter, Scott O; Sullivan, Robert G; Zvolanek, Emily A

    2014-03-25

    As has been noted in many reports and publications, acquiring new or expanded rights-of-way for transmission is a challenging process, because numerous land use and land ownership constraints must be overcome to develop pathways suitable for energy transmission infrastructure. In the eastern U.S., more than twenty federally protected national trails (some of which are thousands of miles long, and cross many states) pose a potential obstacle to the development of new or expanded electricity transmission capacity. However, the scope of this potential problem is not well-documented, and there is no baseline information available that could allow all stakeholders to study routing scenarios that could mitigate impacts on national trails. This report, Electricity Transmission, Pipelines, and National Trails: An Analysis of Current and Potential Intersections on Federal Lands in the Eastern United States, was prepared by the Environmental Science Division of Argonne National Laboratory (Argonne). Argonne was tasked by DOE to analyze the “footprint” of the current network of National Historic and Scenic Trails and the electricity transmission system in the 37 eastern contiguous states, Alaska, and Hawaii; assess the extent to which national trails are affected by electrical transmission; and investigate the extent to which national trails and other sensitive land use types may be affected in the near future by planned transmission lines. Pipelines are secondary to transmission lines for analysis, but are also within the analysis scope in connection with the overall directives of Section 368 of the Energy Policy Act of 2005, and because of the potential for electrical transmission lines being collocated with pipelines. Based on Platts electrical transmission line data, a total of 101 existing intersections with national trails on federal land were found, and 20 proposed intersections. Transmission lines and pipelines are proposed in Alaska; however there are no

  16. Potential alternatives to edible oils for biodiesel production - A review of current work

    International Nuclear Information System (INIS)

    Balat, Mustafa

    2011-01-01

    Biodiesel production is a very modern and technological area for researchers due to the relevance that it is winning everyday because of the increase in the petroleum price and the environmental advantages. Currently, biodiesel is mainly prepared from conventionally grown edible oils such as rapeseed, soybean, sunflower and palm thus leading to alleviate food versus fuel issue. About 7% of global vegetable oil supplies were used for biodiesel production in 2007. Extensive use of edible oils may cause other significant problems such as starvation in developing countries. The use of non-edible plant oils when compared with edible oils is very significant in developing countries because of the tremendous demand for edible oils as food, and they are far too expensive to be used as fuel at present. The production of biodiesel from different non-edible oilseed crops has been extensively investigated over the last few years. (author)

  17. Including Alternative Resources in State Renewable Portfolio Standards: Current Design and Implementation Experience

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, J.; Bird, L.

    2012-11-01

    Currently, 29 states, the District of Columbia, and Puerto Rico have instituted a renewable portfolio standard (RPS). An RPS sets a minimum threshold for how much renewable energy must be generated in a given year. Each state policy is unique, varying in percentage targets, timetables, and eligible resources. This paper examines state experience with implementing renewable portfolio standards that include energy efficiency, thermal resources, and non-renewable energy and explores compliance experience, costs, and how states evaluate, measure, and verify energy efficiency and convert thermal energy. It aims to gain insights from the experience of states for possible federal clean energy policy as well as to share experience and lessons for state RPS implementation.

  18. Future carbon regulations and current investments in alternative coal-fired power plant technologies

    International Nuclear Information System (INIS)

    Sekar, Ram C.; Parsons, John E.; Herzog, Howard J.; Jacoby, Henry D.

    2007-01-01

    We analyze how uncertain future US carbon regulations shape the current choice of the type of power plant to build. Our focus is on two coal-fired technologies, pulverized coal (PC) and integrated coal gasification combined cycle technology (IGCC). The PC technology is cheapest-assuming there is no need to control carbon emissions. The IGCC technology may be cheaper if carbon must be captured. Since power plants last many years and future regulations are uncertain, a US electric utility faces a standard decision under uncertainty. A company will confront the range of possible outcomes, assigning its best estimate of the probability of each scenario, averaging the results and determining the power plant technology with the lowest possible cost inclusive of expected future carbon related costs, whether those costs be in the form of emissions charges paid or capital expenditures for retrofitting to capture carbon. If the company assigns high probability to no regulation or to less stringent regulation of carbon, then it makes sense for it to build the PC plant. But if it assigns sufficient probability to scenarios with more stringent regulation, then the IGCC technology is warranted. We provide some useful benchmarks for possible future regulation and show how these relate back to the relative costs of the two technologies and the optimal technology choice. Few of the policy proposals widely referenced in the public discussion warrant the choice of the IGCC technology. Instead, the PC technology remains the least costly. However, recent carbon prices in the European Emissions Trading System are higher than these benchmarks. If it is any guide to possible future penalties for emissions in the US, then current investment in the IGCC technology is warranted. Of course, other factors need to be factored into the decision as well

  19. Preparation of biological samples for transmission X-ray microanalysis: a review of alternative procedures to the use of sectioned material

    International Nuclear Information System (INIS)

    Sigee, D.C.

    1988-01-01

    Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular. The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case of cell homogenates and biological fluids, the technique has been used mainly with microdroplets of animal material. The use of X-ray microanalysis with purified biochemicals is considered in relation to both particulate and non-particulate samples. In the latter category, the application of this technique for analysis of thin films of metalloprotein is particularly emphasised. It is concluded that wider use could be made of the range of preparative techniques available - both within a particular investigation, and in diverse fields of study. Transmission X-ray microanalysis has implications for environmental, physiological and molecular biology as well as cell biology

  20. Silver eel migration, wind power and alternating current fields; Blankaalsvandring, vindkraft och vaexelstroemsfaelt, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Lagenfelt, Ingvar; Andersson, Ingemar; Westerberg, Haakan

    2012-02-15

    How are eels affected by large offshore wind farms? The study follows the silver eels' migration and behavior at Lillgrund wind farm in Oeresund and the passage over an 130 kV AC cable between the mainland and Oeland. The aim is to see if the AC cable precludes or otherwise affects the eel's ability to reach its destination. Eels migrate up to 7500 km from the Baltic Sea to spawn in the Sargasso Sea. Every delay is of importance for the silver eels, which must be able to travel the entire distance on a single energy reserve. Fish, which make use of the earth's magnetic field for navigation or which are sensitive to electromagnetic fields, may be affected by AC cables on the seabed. The study shows that the silver eels swimming speed was reduced when there was more current in the cable and there was an average delay of 40 minutes before they passed it

  1. NTM stabilization by alternating O-point EC current drive using a high-power diplexer

    Science.gov (United States)

    Kasparek, W.; Doelman, N.; Stober, J.; Maraschek, M.; Zohm, H.; Monaco, F.; Eixenberger, H.; Klop, W.; Wagner, D.; Schubert, M.; Schütz, H.; Grünwald, G.; Plaum, B.; Munk, R.; Schlüter, K. H.; ASDEX Upgrade Team

    2016-12-01

    At the tokamak ASDEX Upgrade, experiments to stabilize neoclassical tearing modes (NTMs) by electron cyclotron (EC) heating and current drive in the O-points of the magnetic islands were performed. For the first time, injection into the O-points of the revolving islands was performed via a fast directional switch, which toggled the EC power between two launchers synchronously to the island rotation. The switching was performed by a resonant diplexer employing a sharp resonance in the transfer function, and a small frequency modulation of the feeding gyrotron around the slope of the resonance. Thus, toggling of the power between the two outputs of the diplexer connected to two articulating launchers was possible. Phasing and control of the modulation were performed via a set of Mirnov coils and appropriate signal processing. In the paper, technological issues, the design of the diplexer, the tracking of the diplexer resonance to the gyrotron frequency, the generation and processing of control signals for the gyrotron, and the typical performance concerning switching contrast and efficiency are discussed. The plasma scenario is described, and plasma experiments are presented, where the launchers scanned the region of the resonant surface continuously and also where the launchers were at a fixed position near to the q  =  1.5-surface. In the second case, complete stabilization of a 3/2 NTM could be reached. These experiments are also seen as a technical demonstration for the applicability of diplexers in large-scale ECRH systems.

  2. Alternatives to current HIV/AIDS policies and practices in South African prisons.

    Science.gov (United States)

    Goyer, K C; Gow, Jeff

    2002-01-01

    Prisoners in South Africa face problems of overcrowding, violence and poor nutrition. Added to this burden in recent times is the increased threat from HIV. The HIV epidemic has been relatively late in coming to South Africa but infection rates are now 20% in the adult population. However, there is no data available on the level of HIV infection in the prison population. Overseas studies suggest that the characteristics of prisoners place them at much greater risk of HIV infection. Factors which contribute to increased levels of HIV infection include poor health care facilities, lack of condoms and lack of disinfectants. Current policies and practices on HIV in prison attempt to balance the constraints of limited resources with the need to preserve prisoner human rights. The outcomes include: mass testing not freely available, HIV education is limited, and early release of prisoners with advanced AIDS is not allowed. Constraints on the implementation of effective HIV prevention strategies include: bureaucratic inefficiency, lack of resources, and a reluctance by prison authorities to address the issue of HIV in prison. These problems can possibly be overcome by addressing the issue from both management and prisoner perspectives. On the management side, increased resources, increased training of prison officials, and increased political commitment to address the issue are required. Outside partnerships are probably required for an effective response. Prisoners require better nutrition, better living conditions, better health care, freely available condoms and disinfectants.

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

    Science.gov (United States)

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

    2015-10-01

    Potential drop techniques are of two types: the direct current potential drop (DCPD) technique and alternating current potential drop (ACPD) technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  4. A novel automated alternating current biosusceptometry method to characterization of controlled-release magnetic floating tablets of metronidazole.

    Science.gov (United States)

    Ferrari, Priscileila Colerato; dos Santos Grossklauss, Dany Bruno Borella; Alvarez, Matheus; Paixão, Fabiano Carlos; Andreis, Uilian; Crispim, Alexandre Giordano; de Castro, Ana Dóris; Evangelista, Raul Cesar; de Arruda Miranda, José Ricardo

    2014-08-01

    Alternating Current Biosusceptometry is a magnetically method used to characterize drug delivery systems. This work presents a system composed by an automated ACB sensor to acquire magnetic images of floating tablets. The purpose of this study was to use an automated Alternating Current Biosusceptometry (ACB) to characterize magnetic floating tablets for controlled drug delivery. Floating tablets were prepared with hydroxypropyl methylcellulose (HPMC) as hydrophilic gel material, sodium bicarbonate as gas-generating agent and ferrite as magnetic marker. ACB was used to characterize the floating lag time and the tablet hydration rate, by quantification of the magnetic images to magnetic area. Besides the buoyancy, the floating tablets were evaluated for weight uniformity, hardness, swelling and in vitro drug release. The optimized tablets were prepared with equal amounts of HPMC and ferrite, and began to float within 4 min, maintaining the flotation during more than 24 h. The data of all physical parameters lied within the pharmacopeial limits. Drug release at 24 h was about 40%. The ACB results showed that this study provided a new approach for in vitro investigation of controlled-release dosage forms. Moreover, using automated ACB will also be possible to test these parameters in humans allowing to establish an in vitro.in vivo correlation (IVIVC).

  5. Characterizing AISI 1045 steel surface duplex-treated by alternating current field enhanced pack aluminizing and nitriding

    Science.gov (United States)

    Xie, Fei; Zhang, Ge; Pan, Jianwei

    2018-02-01

    Thin cases and long treating time are shortcomings of conventional duplex treatment of aluminizing followed by nitriding (DTAN). Alternating current field (ACF) enhanced DTAN was carried out on AISI 1045 steel by applying an ACF to treated samples and treating agents with a pair of electrodes for overcoming those shortcomings. By investigating cases' structures, phases, composition and hardness distributions of differently treated samples, preliminary studies were made on characterizations of the ACF enhanced duplex treatment to AISI 1045 steel. The results show that, with the help of the ACF, the surface Al-rich phase Al5Fe2 formed in conventional pack aluminizing can be easily avoided and the aluminizing process is dramatically promoted. The aluminizing case can be nitrided either with conventional pack nitriding or ACF enhanced pack nitriding. By applying ACF to pack nitriding, the diffusion of nitrogen into the aluminizing case is promoted. AlN, Fe2∼3N and solid solution of N in iron are efficiently formed as a result of reactions of N with the aluminizing case. A duplex treated case with an effective thickness of more than 170 μm can be obtained by the alternating current field enhanced 4 h pack aluminizing plus 4 h pack nitriding.

  6. Optical transmission of low-level signals with high dynamic range using the optically-coupled current-mirror architecture

    Energy Technology Data Exchange (ETDEWEB)

    Camin, Daniel V. [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy)]. E-mail: Daniel.Victor.Camin@mi.infn.it; Grassi, Valerio [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy); De Donato, Cinzia [Dipartimento di Fisica dell' Universita degli Studi di Milano and INFN, Milan (Italy)

    2007-03-01

    In this paper we illustrate the application of a novel circuit architecture, the Optically-Coupled Current-Mirror (OCCM), conceived for the linear transmission of analogue signals via fibre optics. We installed 880 OCCMs in the PMTs of the first two telescopes of the cosmic-ray experiment Pierre Auger. The Pierre Auger Observatory (PAO) has been designed to increase the statistics of cosmic-rays with energies above 10{sup 18}eV. Two different techniques have been adopted: the Surface Detector (SD) modules that comprise 1600 tanks spaced each other by 1.5km within an area of 3000km{sup 2}. On the other side there are four buildings, the Optical Stations (OS), in which six telescopes are installed in each one of the four OS, at the periphery of the site, looking inwards. The telescopes are sensitive to the UV light created at the moment a high-energy shower develops in the atmosphere and is within the field-of-view (FOV) of the telescopes. The PAO is located in the Northern Patagonia, not far from the Cordillera de Los Andes, in Argentina. Both detector types, FD telescopes and SD modules, are sensitive to the UV light resulting from the interaction of high-energy particles and the nitrogen molecules in the atmosphere. The UV-sensitive telescopes operate only at night when the sky is completely dark. Otherwise, the light collected by the telescopes may give origin to severe damage in particular if those telescopes point at twilight or to artificial light sources. The duty cycle of the telescope's operation is therefore limited to about 10% or slightly more than that, if data are taken also when there is a partial presence of the Moon. The SD modules establish, independently of the telescopes, the geometry of the event. At the same time a shower reconstruction is performed using the telescope's data, independently of the SD modules. Use of both sets of data, taken by the FD telescopes and by the SD modules, allows the hybrid reconstruction that significantly

  7. Optical transmission of low-level signals with high dynamic range using the optically-coupled current-mirror architecture

    International Nuclear Information System (INIS)

    Camin, Daniel V.; Grassi, Valerio; De Donato, Cinzia

    2007-01-01

    In this paper we illustrate the application of a novel circuit architecture, the Optically-Coupled Current-Mirror (OCCM), conceived for the linear transmission of analogue signals via fibre optics. We installed 880 OCCMs in the PMTs of the first two telescopes of the cosmic-ray experiment Pierre Auger. The Pierre Auger Observatory (PAO) has been designed to increase the statistics of cosmic-rays with energies above 10 18 eV. Two different techniques have been adopted: the Surface Detector (SD) modules that comprise 1600 tanks spaced each other by 1.5km within an area of 3000km 2 . On the other side there are four buildings, the Optical Stations (OS), in which six telescopes are installed in each one of the four OS, at the periphery of the site, looking inwards. The telescopes are sensitive to the UV light created at the moment a high-energy shower develops in the atmosphere and is within the field-of-view (FOV) of the telescopes. The PAO is located in the Northern Patagonia, not far from the Cordillera de Los Andes, in Argentina. Both detector types, FD telescopes and SD modules, are sensitive to the UV light resulting from the interaction of high-energy particles and the nitrogen molecules in the atmosphere. The UV-sensitive telescopes operate only at night when the sky is completely dark. Otherwise, the light collected by the telescopes may give origin to severe damage in particular if those telescopes point at twilight or to artificial light sources. The duty cycle of the telescope's operation is therefore limited to about 10% or slightly more than that, if data are taken also when there is a partial presence of the Moon. The SD modules establish, independently of the telescopes, the geometry of the event. At the same time a shower reconstruction is performed using the telescope's data, independently of the SD modules. Use of both sets of data, taken by the FD telescopes and by the SD modules, allows the hybrid reconstruction that significantly improves the data

  8. Electrical Structure of Future Off-shore Wind Power Plant with a High Voltage Direct Current Power Transmission

    DEFF Research Database (Denmark)

    Sharma, Ranjan

    The increasing demand of electric power and the growing consciousness towards the changing climate has led to a rapid development of renewable energy in the recent years. Among all, wind energy has been the fastest growing energy source in the last decade. But the growing size of wind power plants......, better wind conditions at off-shore and the general demand to put them out of sight have all contributed to the installation of large wind power plants in off-shore condition. However, moving wind power plants far out in the off-shore comes with many associated problems. One of the main challenges...... is the transmission of power over long distance. Historically, the power transmission from off-shore wind power plants has been done via HVAC submarine cables. This provides a simple solution, but AC cables cannot be arbitrarily long. It is shown in the report that major issues with HVAC cable transmission system...

  9. Electro-optically responsive composites of gold nanospheres in 5CB liquid crystal under direct current and alternating current joint action

    International Nuclear Information System (INIS)

    Hadjichristov, Georgi B.; Marinov, Yordan G.; Petrov, Alexander G.; Bruno, Emanuela; Marino, Lucia; Scaramuzza, Nicola

    2014-01-01

    Direct current (DC) electro-optical (EO) control of transmitted laser beam intensity based on EO controlled coherent light scattering and diffraction by stationary longitudinal texture pattern (LTP) is achieved in planar-oriented cells with a composite mixture of polymer-coated gold spherical nanoparticles (Au-NPs) with a mean diameter of about 12 nm and the room-temperature nematic pentylcyanobiphenyl (5CB). At relatively low DC voltage of about 5 V, the effective scattering/diffraction by Au-NPs/5CB composites leads to a spatial spreading of transmitted coherent light from a low-power continuous wave laser beam, resulting in a drastic reduction of its local intensity. The effect is polarization dependent and is strongest when the polarization of the input laser beam is along the LTP. The EO response of Au-NPs/5CB mixtures is studied under DC and alternating current (AC) joint action with the aim of the potential use of these composite materials as EO controlled diffusers. The specific V-shaped sharp dip in the DC voltage-dependent coherent light transmittance of Au-NPs/5CB planar films, as well as the possibility for erasing the scattering/diffractive LTP in the films by joint low AC voltage, can be useful for EO applications in the field of process control and for detection of weak dynamic electric fields

  10. Electro-optically responsive composites of gold nanospheres in 5CB liquid crystal under direct current and alternating current joint action

    Energy Technology Data Exchange (ETDEWEB)

    Hadjichristov, Georgi B.; Marinov, Yordan G.; Petrov, Alexander G. [Institute of Solid State Physics, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Bruno, Emanuela [Dipartimento di Fisica, Università della Calabria, Via Pietro Bucci, Cubo 31C, 87036 Rende (CS) (Italy); Marino, Lucia, E-mail: lucia.marino@fis.unical.it [CNR-IPCF UoS di Cosenza, Licryl Laboratory, and Centro di Eccellenza CEMIF.CAL, Università della Calabria, 87036 Rende (CS) (Italy); Scaramuzza, Nicola [Dipartimento di Fisica, Università della Calabria, Via Pietro Bucci, Cubo 31C, 87036 Rende (CS) (Italy); CNR-IPCF UoS di Cosenza, Licryl Laboratory, and Centro di Eccellenza CEMIF.CAL, Università della Calabria, 87036 Rende (CS) (Italy)

    2014-02-28

    Direct current (DC) electro-optical (EO) control of transmitted laser beam intensity based on EO controlled coherent light scattering and diffraction by stationary longitudinal texture pattern (LTP) is achieved in planar-oriented cells with a composite mixture of polymer-coated gold spherical nanoparticles (Au-NPs) with a mean diameter of about 12 nm and the room-temperature nematic pentylcyanobiphenyl (5CB). At relatively low DC voltage of about 5 V, the effective scattering/diffraction by Au-NPs/5CB composites leads to a spatial spreading of transmitted coherent light from a low-power continuous wave laser beam, resulting in a drastic reduction of its local intensity. The effect is polarization dependent and is strongest when the polarization of the input laser beam is along the LTP. The EO response of Au-NPs/5CB mixtures is studied under DC and alternating current (AC) joint action with the aim of the potential use of these composite materials as EO controlled diffusers. The specific V-shaped sharp dip in the DC voltage-dependent coherent light transmittance of Au-NPs/5CB planar films, as well as the possibility for erasing the scattering/diffractive LTP in the films by joint low AC voltage, can be useful for EO applications in the field of process control and for detection of weak dynamic electric fields.

  11. The opinion of Turkish cardiologists on current malpractice system and an alternative patient compensation system proposal: PCS study group.

    Science.gov (United States)

    Olcay, Ayhan; Emren, Sadık Volkan; Babür Güler, Gamze; Güler, Ekrem; Ertunç, Vedat; Berilgen, Rida; Aslan, Abdullah; Şimşek, Ersin Çağrı; Gölcük, Şükriye Ebru; Yalın, Kıvanç

    2017-10-01

    Cardiologists participate in the diagnosis and interventional treatment of numerous high-risk patients. The goal of this study was to investigate how the current malpractice system in Turkey influences cardiologists' diagnostic and interventional behavior and to obtain their opinions about an alternative patient compensation system. The present cross-sectional study assessed the practice of defensive medicine among cardiologists who are actively working in various types of workplace within the Turkish healthcare system. A 24-item questionnaire was distributed to cardiology residents, specialists, and academics in Turkey in print format, by electronic mail, or via cell phone message. A total of 253 cardiologists responded to the survey. Among them, 29 (11.6%) had been sued for malpractice claims in the past. Of the cardiologists who had been sued, 2 (6.9%) had been ordered to pay financial compensation, and 1 (3.4%) was given a sentence of imprisonment due to negligence. In all, 132 (52.8%) of the surveyed cardiologists reported that they had changed their practices due to fear of litigation, and 232 (92.8%) reported that they would prefer the new proposed patient compensation system to the current malpractice system. Among the cardiologists surveyed, 78.8% indicated that malpractice fear had affected their decision-making with regard to requesting computed tomography angiography or thallium scintigraphy, 71.6% for coronary angiography, 20% for stent implantation, and 83.2% for avoiding treating high-risk patients. The results of this survey demonstrated that cardiologists may request unnecessary tests and perform unneeded interventions due to the fear of malpractice litigation fear. Many also avoid high-risk patients and interventions. The majority indicated that they would prefer the proposed alternative patient compensation system to the current malpractice system.

  12. Bilateral 5 Hz transcranial alternating current stimulation on fronto-temporal areas modulates resting-state EEG.

    Science.gov (United States)

    D'Atri, Aurora; Romano, Claudia; Gorgoni, Maurizio; Scarpelli, Serena; Alfonsi, Valentina; Ferrara, Michele; Ferlazzo, Fabio; Rossini, Paolo Maria; De Gennaro, Luigi

    2017-11-15

    Rhythmic non-invasive brain stimulations are promising tools to modulate brain activity by entraining neural oscillations in specific cortical networks. The aim of the study was to assess the possibility to influence the neural circuits of the wake-sleep transition in awake subjects via a bilateral transcranial alternating current stimulation at 5 Hz (θ-tACS) on fronto-temporal areas. 25 healthy volunteers participated in two within-subject sessions (θ-tACS and sham), one week apart and in counterbalanced order. We assessed the stimulation effects on cortical EEG activity (28 derivations) and self-reported sleepiness (Karolinska Sleepiness Scale). θ-tACS induced significant increases of the theta activity in temporo-parieto-occipital areas and centro-frontal increases in the alpha activity compared to sham but failed to induce any online effect on sleepiness. Since the total energy delivered in the sham condition was much less than in the active θ-tACS, the current data are unable to isolate the specific effect of entrained theta oscillatory activity per se on sleepiness scores. On this basis, we concluded that θ-tACS modulated theta and alpha EEG activity with a topography consistent with high sleep pressure conditions. However, no causal relation can be traced on the basis of the current results between these rhythms and changes on sleepiness.

  13. Alternative fuel buses currently in use in China: Life-cycle fossil energy use, GHG emissions and policy recommendations

    International Nuclear Information System (INIS)

    Ou Xunmin; Zhang Xiliang; Chang Shiyan

    2010-01-01

    The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology R and D for future potential applications; and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources.

  14. Alternative fuel buses currently in use in China: Life-cycle fossil energy use, GHG emissions and policy recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Ou Xunmin, E-mail: oxm07@mails.tsinghua.edu.c [School of Public Policy and Management (SPPM), Tsinghua University, Beijing 100084 (China); China Automotive Energy Research Center (CAERC), Tsinghua University, Beijing 100084 (China); Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China); Zhang Xiliang, E-mail: zhang_xl@tsinghua.edu.c [China Automotive Energy Research Center (CAERC), Tsinghua University, Beijing 100084 (China); Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China); Chang Shiyan [China Automotive Energy Research Center (CAERC), Tsinghua University, Beijing 100084 (China); Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China)

    2010-01-15

    The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology R and D for future potential applications; and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources.

  15. Alternative fuel buses currently in use in China. Life-cycle fossil energy use, GHG emissions and policy recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Ou, Xunmin [School of Public Policy and Management (SPPM), Tsinghua University, Beijing 100084 (China); China Automotive Energy Research Center (CAERC), Tsinghua University, Beijing 100084 (China); Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China); Zhang, Xiliang; Chang, Shiyan [China Automotive Energy Research Center (CAERC), Tsinghua University, Beijing 100084 (China); Institute of Energy, Environment and Economy (3E), Tsinghua University, Beijing 100084 (China)

    2010-01-15

    The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology R and D for future potential applications; and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources. (author)

  16. Corrosion Behavior of X80 Steel with Coupled Coating Defects under Alternating Current Interference in Alkaline Environment.

    Science.gov (United States)

    Li, Zhong; Li, Caiyu; Qian, Hongchang; Li, Jun; Huang, Liang; Du, Cuiwei

    2017-06-28

    The corrosion behavior of X80 steel in the presence of coupled coating defects was simulated and studied under the interference of alternating current (AC) in an alkaline environment. The results from electrochemical measurements showed that the electrode potential of the coating defect with the smaller exposed area was lower than that with the larger area, which indicated that the steel with the smaller coating defect was more prone to corrosion. The result of weight loss tests also showed that the smaller coating defect had induced a higher corrosion rate. However, the corrosion rate of X80 steel at the larger coating defect decreased gradually with the increase of the larger defect area at a constant smaller defect area. The corrosion morphology images showed that the coating defects with smaller areas suffered from more severe pitting corrosion.

  17. Characterization of interference thin films grown on stainless steel surface by alternate pulse current in a sulphochromic solution

    Directory of Open Access Journals (Sweden)

    Rosa Maria Rabelo Junqueira

    2008-12-01

    Full Text Available The aim of this work was to characterize thin interference films grown on the surface of AISI 304 stainless steel for decorative purposes. Films were grown in a sulphochromic solution at room temperature by an alternating pulse current method. The morphology and chemical state of the elements in the films were investigated by field emission scanning electron microscopy (FESEM, atomic force microscopy (AFM, glow discharge optical emission spectrometry (GDOES, and infrared Fourier transform spectroscopy (FTIR. Depth-sensing indentation (DSI experiments and wear abrasion tests were employed to assess the mechanical resistance of the films. The coloration process resulted in porous thin films which increased the surface roughness of the substrate. The interference films mainly consisted of hydrated chromium oxide containing iron. Increasing film thickness produced different colors and affected the mechanical properties of the coating-substrate system. Thicker films, such as those producing gold and green colors, were softer but more abrasion resistant.

  18. Probing phase- and frequency-dependent characteristics of cortical interneurons using combined transcranial alternating current stimulation and transcranial magnetic stimulation.

    Science.gov (United States)

    Hussain, Sara J; Thirugnanasambandam, Nivethida

    2017-06-01

    Paired-pulse transcranial magnetic stimulation (TMS) and peripheral stimulation combined with TMS can be used to study cortical interneuronal circuitry. By combining these procedures with concurrent transcranial alternating current stimulation (tACS), Guerra and colleagues recently showed that different cortical interneuronal populations are differentially modulated by the phase and frequency of tACS-imposed oscillations (Guerra A, Pogosyan A, Nowak M, Tan H, Ferreri F, Di Lazzaro V, Brown P. Cerebral Cortex 26: 3977-2990, 2016). This work suggests that different cortical interneuronal populations can be characterized by their phase and frequency dependency. Here we discuss how combining TMS and tACS can reveal the frequency at which cortical interneuronal populations oscillate, the neuronal origins of behaviorally relevant cortical oscillations, and how entraining cortical oscillations could potentially treat brain disorders. Copyright © 2017 the American Physiological Society.

  19. Elicitors as alternative strategy to pesticides in grapevine? Current knowledge on their mode of action from controlled conditions to vineyard.

    Science.gov (United States)

    Delaunois, Bertrand; Farace, Giovanni; Jeandet, Philippe; Clément, Christophe; Baillieul, Fabienne; Dorey, Stéphan; Cordelier, Sylvain

    2014-04-01

    Development and optimisation of alternative strategies to reduce the use of classic chemical inputs for protection against diseases in vineyard is becoming a necessity. Among these strategies, one of the most promising consists in the stimulation and/or potentiation of the grapevine defence responses by the means of elicitors. Elicitors are highly diverse molecules both in nature and origins. This review aims at providing an overview of the current knowledge on these molecules and will highlight their potential efficacy from the laboratory in controlled conditions to vineyards. Recent findings and concepts (especially on plant innate immunity) and the new terminology (microbe-associated molecular patterns, effectors, etc.) are also discussed in this context. Other objectives of this review are to highlight the difficulty of transferring elicitors use and results from the controlled conditions to the vineyard, to determine their practical and effective use in viticulture and to propose ideas for improving their efficacy in non-controlled conditions.

  20. Herbal Medicines: challenges in the modern world. Part 5. status and current directions of complementary and alternative herbal medicine worldwide.

    Science.gov (United States)

    Enioutina, Elena Yu; Salis, Emma R; Job, Kathleen M; Gubarev, Michael I; Krepkova, Lubov V; Sherwin, Catherine M T

    2017-03-01

    Herbal medicine (HM) use is growing worldwide. Single herb preparations, ethnic and modern HM formulations are widely used as adjunct therapies or to improve consumer wellbeing. Areas covered: This final part in the publication series summarizes common tendencies in HM use as adjunct or alternative medicine, education of healthcare professionals and consumers, current and proposed guidelines regulating of production. We discuss potential HM-HM and HM-drug interactions that could lead to severe adverse events in situations where HMs are taken without proper medical professional oversight. Expert commentary: A number of serious problems have arisen with the steady global increase in HM use. HM interaction with conventional drugs (CD) may result in inadequate dosing of CD or adverse reactions; HM-HM interaction within herbal supplements could lead to toxicity of formulations. Inadequate education of clinicians and patients regarding medicinal properties of HMs must be addressed regionally and globally to ensure consumer safety.

  1. Susceptibility of CoFeB/AlOx/Co Magnetic Tunnel Junctions to Low-Frequency Alternating Current

    Directory of Open Access Journals (Sweden)

    Yuan-Tsung Chen

    2013-10-01

    Full Text Available This investigation studies CoFeB/AlOx/Co magnetic tunneling junction (MTJ in the magnetic field of a low-frequency alternating current, for various thicknesses of the barrier layer AlOx. The low-frequency alternate-current magnetic susceptibility (χac and phase angle (θ of the CoFeB/AlOx/Co MTJ are determined using an cac analyzer. The driving frequency ranges from 10 to 25,000 Hz. These multilayered MTJs are deposited on a silicon substrate using a DC and RF magnetron sputtering system. Barrier layer thicknesses are 22, 26, and 30 Å. The X-ray diffraction patterns (XRD include a main peak at 2θ = 44.7° from hexagonal close-packed (HCP Co with a highly (0002 textured structure, with AlOx and CoFeB as amorphous phases. The full width at half maximum (FWHM of the Co(0002 peak, decreases as the AlOx thickness increases; revealing that the Co layer becomes more crystalline with increasing thickness. χac result demonstrates that the optimal resonance frequency (fres that maximizes the χac value is 500 Hz. As the frequency increases to 1000 Hz, the susceptibility decreases rapidly. However, when the frequency increases over 1000 Hz, the susceptibility sharply declines, and almost closes to zero. The experimental results reveal that the mean optimal susceptibility is 1.87 at an AlOx barrier layer thickness of 30 Å because the Co(0002 texture induces magneto-anisotropy, which improves the indirect CoFeB and Co spin exchange-coupling strength and the χac value. The results concerning magnetism indicate that the magnetic characteristics are related to the crystallinity of Co.

  2. Both the cutaneous sensation and phosphene perception are modulated in a frequency-specific manner during transcranial alternating current stimulation.

    Science.gov (United States)

    Turi, Zs; Ambrus, G G; Janacsek, K; Emmert, K; Hahn, L; Paulus, W; Antal, A

    2013-01-01

    Transcranial alternating current stimulation (tACS) is a non-invasive stimulation technique for shaping neuroplastic processes and possibly entraining ongoing neural oscillations in humans. Despite the growing number of studies using tACS, we know little about the procedural sensations caused by stimulation. In order to fill this gap, we explored the cutaneous sensation and phosphene perception during tACS. Twenty healthy participants took part in a randomized, single-blinded, sham-controlled study, where volunteers received short duration stimulation at 1.0 mA intensity between 2 to 250 Hz using the standard left motor cortex-contralateral supraorbital montage. We recorded the perception onset latency and the strength of the sensations assessed by visual rating scale as dependent variables. We found that tACS evoked both cutaneous sensation and phosphene perception in a frequency-dependent manner. Our results show that the most perceptible procedural sensations were induced in the beta and gamma frequency range, especially at 20 Hz, whereas minimal procedural sensations were indicated in the ripple range (140 and 250 Hz). We believe that our results provide a relevant insight into the procedural sensations caused by oscillatory currents, and will offer a basis for developing more sophisticated stimulation protocols and study designs for future investigations.

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

    Directory of Open Access Journals (Sweden)

    Li Yuting

    2015-10-01

    Full Text Available Potential drop techniques are of two types: the direct current potential drop (DCPD technique and alternating current potential drop (ACPD technique, and both of them are used in nondestructive testing. ACPD, as a kind of valid method in sizing metal cracks, has been applied to evaluate metal structures. However, our review of most available approaches revealed that some improvements can be done in measuring depth of metal bottom crack by means of ACPD, such as accuracy and sensitivity of shallow crack. This paper studied a novel method which utilized the slope of voltage ratio-frequency curve to solve bottom crack depth by using a simple mathematic equation based on finite element analysis. It is found that voltage ratio varies linearly with frequency in the range of 5-15 Hz; this range is slightly higher than the equivalent frequency and lower than semi-permeable frequency. Simulation and experiment show that the novel method can measure the bottom crack depth accurately.

  4. Boosting the LTP-like plasticity effect of intermittent theta-burst stimulation using gamma transcranial alternating current stimulation.

    Science.gov (United States)

    Guerra, Andrea; Suppa, Antonio; Bologna, Matteo; D'Onofrio, Valentina; Bianchini, Edoardo; Brown, Peter; Di Lazzaro, Vincenzo; Berardelli, Alfredo

    2018-03-24

    Transcranial Alternating Current Stimulation (tACS) consists in delivering electric current to the brain using an oscillatory pattern that may entrain the rhythmic activity of cortical neurons. When delivered at gamma frequency, tACS modulates motor performance and GABA-A-ergic interneuron activity. Since interneuronal discharges play a crucial role in brain plasticity phenomena, here we co-stimulated the primary motor cortex (M1) in healthy subjects by means of tACS during intermittent theta-burst stimulation (iTBS), a transcranial magnetic stimulation paradigm known to induce long-term potentiation (LTP)-like plasticity. We measured and compared motor evoked potentials before and after gamma, beta and sham tACS-iTBS. While we delivered gamma-tACS, we also measured short-interval intracortical inhibition (SICI) to detect any changes in GABA-A-ergic neurotransmission. Gamma, but not beta and sham tACS, significantly boosted and prolonged the iTBS-induced after-effects. Interestingly, the extent of the gamma tACS-iTBS after-effects correlated directly with SICI changes. Overall, our findings point to a link between gamma oscillations, interneuronal GABA-A-ergic activity and LTP-like plasticity in the human M1. Gamma tACS-iTBS co-stimulation might represent a new strategy to enhance and prolong responses to plasticity-inducing protocols, thereby lending itself to future applications in the neurorehabilitation setting. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Probing Electrode Heterogeneity Using Fourier-Transformed Alternating Current Voltammetry: Application to a Dual-Electrode Configuration.

    Science.gov (United States)

    Tan, Sze-Yin; Unwin, Patrick R; Macpherson, Julie V; Zhang, Jie; Bond, Alan M

    2017-03-07

    Quantitative studies of electron transfer processes at electrode/electrolyte interfaces, originally developed for homogeneous liquid mercury or metallic electrodes, are difficult to adapt to the spatially heterogeneous nanostructured electrode materials that are now commonly used in modern electrochemistry. In this study, the impact of surface heterogeneity on Fourier-transformed alternating current voltammetry (FTACV) has been investigated theoretically under the simplest possible conditions where no overlap of diffusion layers occurs and where numerical simulations based on a 1D diffusion model are sufficient to describe the mass transport problem. Experimental data that meet these requirements can be obtained with the aqueous [Ru(NH 3 ) 6 ] 3+/2+ redox process at a dual-electrode system comprised of electrically coupled but well-separated glassy carbon (GC) and boron-doped diamond (BDD) electrodes. Simulated and experimental FTACV data obtained with this electrode configuration, and where distinctly different heterogeneous charge transfer rate constants (k 0 values) apply at the individual GC and BDD electrode surfaces, are in excellent agreement. Principally, because of the far greater dependence of the AC current magnitude on k 0 , it is straightforward with the FTACV method to resolve electrochemical heterogeneities that are ∼1-2 orders of magnitude apart, as applies in the [Ru(NH 3 ) 6 ] 3+/2+ dual-electrode configuration experiments, without prior knowledge of the individual kinetic parameters (k 0 1 and k 0 2 ) or the electrode size ratio (θ 1 :θ 2 ). In direct current voltammetry, a difference in k 0 of >3 orders of magnitude is required to make this distinction.

  6. Effects of 10 Hz and 20 Hz Transcranial Alternating Current Stimulation on Automatic Motor Control.

    Science.gov (United States)

    Cappon, Davide; D'Ostilio, Kevin; Garraux, Gaëtan; Rothwell, John; Bisiacchi, Patrizia

    2016-01-01

    In a masked prime choice reaction task, presentation of a compatible prime increases the reaction time to the following imperative stimulus if the interval between mask and prime is around 80-250 ms. This is thought to be due to automatic suppression of the motor plan evoked by the prime, which delays reaction to the imperative stimulus. Oscillatory activity in motor networks around the beta frequency range of 20 Hz is important in suppression of movement. Transcranial alternating current at 20 Hz may be able to drive oscillations in the beta range. To investigate whether transcranial alternating current stimulation (tACS) at 20 Hz would increase automatic inhibition in a masked prime task. As a control we used 10 Hz tACS. Stimulation was delivered at alpha (10 Hz) and beta (20 Hz) frequency over the supplementary motor area and the primary motor cortex (simultaneous tACS of SMA-M1), which are part of the BG-cortical motor loop, during the execution of the subliminal masked prime left/right choice reaction task. We measured the effects on reaction times. Corticospinal excitability was assessed by measuring the amplitude of motor evoked potentials (MEPs) evoked in the first dorsal interosseous muscle by transcranial magnetic stimulation (TMS) over M1. The 10 and 20-Hz tACS over SMA-M1 had different effects on automatic inhibition. The 20 Hz tACS increased the duration of automatic inhibition whereas it was decreased by 10 Hz tACS. Neurophysiologically, 20 Hz tACS reduced the amplitude of MEPs evoked from M1, whereas there was no change after 10 Hz tACS. Automatic mechanisms of motor inhibition can be modulated by tACS over motor areas of cortex. tACS may be a useful additional tool to investigate the causal links between endogenous brain oscillations and specific cognitive processes. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 18-month effectiveness of short-course antiretroviral regimens combined with alternatives to breastfeeding to prevent HIV mother-to-child transmission.

    Directory of Open Access Journals (Sweden)

    Valériane Leroy

    Full Text Available OBJECTIVE: We assessed the 18-month effectiveness of short-course (sc antiretroviral peripartum regimens combined with alternatives to prolonged breastfeeding to prevent mother-to-child transmission (MTCT of HIV-1 in Abidjan, Côte d'Ivoire. METHODOLOGY: HIV-1 infected pregnant women received from >/=32-36 weeks of gestation scZidovudine (ZDV+/-Lamivudine (3TC+single-dose Nevirapine (sdNVP at delivery within the ANRS 1201/1202 DITRAME-Plus cohort (2001-2003. Neonates received a sdNVP+7-day ZDV prophylaxis. Two infant-feeding interventions were systematically offered free of charge: formula-feeding or exclusive shortened breastfeeding with early cessation from four months. The reference group was the ANRS 049a DITRAME cohort (1994-2000 exposed to scZDV from 36 weeks, then to prolonged breastfeeding. Pediatric HIV infection was defined by a positive plasma HIV-1 RNA at any age, or if aged >/=18 months, a positive HIV-1 serology. Turnbull estimates of cumulative transmission risks (CTR and effectiveness (HIV-free survival were compared by exposure group using a Cox model. FINDINGS: Among 926 live-born children enrolled, 107 (11.6% were HIV-infected at 18 months. CTRs were 22.3% (95% confidence interval[CI]:16-30% in the 238 ZDV long-term breastfed reference group, 15.9% (CI:10-27% in the 169 ZDV+sdNVP shortened breastfed group; 9.4% (CI:6-14% in the 195 ZDV+sdNVP formula-fed group; 6.8% (CI:4-11% in the 198 ZDV+3TC+sdNVP shortened breastfed group, and 5.6% (CI:2-10% in the 126 ZDV+3TC+sdNVP formula-fed group. Each combination had a significantly higher effectiveness than the ZDV long-term breastfed group except for ZDV+sdNVP shortened breastfed children, ranging from 51% (CI:20-70% for ZDV+sdNVP formula fed children to 63% (CI:40-80% for ZDV+3TC+NVPsd shortened breastfed children, after adjustment for maternal eligibility for antiretroviral therapy (ART, home delivery and low birth-weight. Substantial MTCT risk reductions are reachable in Africa

  8. Transcranial alternating current stimulation (tACS increases risk taking behavior in the Balloon Analogue Risk Task

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    Tal eSela

    2012-02-01

    Full Text Available The process of evaluating risks and benefits involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC. It has been proposed that in conflict and reward situations, theta-band (4–8 Hz oscillatory activity in the frontal cortex may reflect an electrophysiological mechanism for coordinating neural networks monitoring behavior, as well as facilitating task-specific adaptive changes. The goal of the present study was to investigate the hypothesis that theta-band oscillatory balance between right and left frontal and prefrontal regions, with a predominance role to the right hemisphere, is crucial for regulatory control during decision-making under risk. In order to explore this hypothesis, we used transcranial Alternating Current Stimulation (tACS, a novel technique that provides the opportunity to explore the functional role of neuronal oscillatory activities and to establish a causal link between specific oscillations and functional lateralization in risky decision-making situations. For this aim, healthy participants were randomly allocated to one of three stimulation groups (LH stimulation / RH stimulation / Sham stimulation, with active AC stimulation delivered in a frequency-dependent manner (at 6.5 Hz; 1mA peak to-peak. During the AC stimulation, participants performed the Balloon Analog Risk Task. This experiment revealed that participants receiving LH stimulation displayed riskier decision-making style compared to sham and RH stimulation groups. However, there was no difference in decision-making behaviors between sham and RH stimulation groups. The current study extends the notion that DLPFC activity is critical for adaptive decision-making in the context of risk-taking and emphasis the role of theta-band oscillatory activity during risky decision-making situations.

  9. Alternating Current-Dielectrophoresis Collection and Chaining of Phytoplankton on Chip: Comparison of Individual Species and Artificial Communities

    Directory of Open Access Journals (Sweden)

    Coralie Siebman

    2017-01-01

    Full Text Available The capability of alternating current (AC dielectrophoresis (DEP for on-chip capture and chaining of the three species representative of freshwater phytoplankton was evaluated. The effects of the AC field intensity, frequency and duration on the chaining efficiency and chain lengths of green alga Chlamydomonas reinhardtii, cyanobacterium Synechocystis sp. and diatom Cyclotella meneghiniana were characterized systematically. C. reinhardtii showed an increase of the chaining efficiency from 100 Hz to 500 kHz at all field intensities; C. meneghiniana presented a decrease of chaining efficiency from 100 Hz to 1 kHz followed by a significant increase from 1 kHz to 500 kHz, while Synechocystis sp. exhibited low chaining tendency at all frequencies and all field intensities. The experimentally-determined DEP response and cell alignment of each microorganism were in agreement with their effective polarizability. Mixtures of cells in equal proportion or 10-times excess of Synechocystis sp. showed important differences in terms of chaining efficiency and length of the chains compared with the results obtained when the cells were alone in suspension. While a constant degree of chaining was observed with the mixture of C. reinhardtii and C. meneghiniana, the presence of Synechocystis sp. in each mixture suppressed the formation of chains for the two other phytoplankton species. All of these results prove the potential of DEP to discriminate different phytoplankton species depending on their effective polarizability and to enable their manipulation, such as specific collection or separation in freshwater.

  10. Novel design of high voltage pulse source for efficient dielectric barrier discharge generation by using silicon diodes for alternating current

    Science.gov (United States)

    Truong, Hoa Thi; Hayashi, Misaki; Uesugi, Yoshihiko; Tanaka, Yasunori; Ishijima, Tatsuo

    2017-06-01

    This work focuses on design, construction, and optimization of configuration of a novel high voltage pulse power source for large-scale dielectric barrier discharge (DBD) generation. The pulses were generated by using the high-speed switching characteristic of an inexpensive device called silicon diodes for alternating current and the self-terminated characteristic of DBD. The operation started to be powered by a primary DC low voltage power supply flexibly equipped with a commercial DC power supply, or a battery, or DC output of an independent photovoltaic system without transformer employment. This flexible connection to different types of primary power supply could provide a promising solution for the application of DBD, especially in the area without power grid connection. The simple modular structure, non-control requirement, transformer elimination, and a minimum number of levels in voltage conversion could lead to a reduction in size, weight, simple maintenance, low cost of installation, and high scalability of a DBD generator. The performance of this pulse source has been validated by a load of resistor. A good agreement between theoretically estimated and experimentally measured responses has been achieved. The pulse source has also been successfully applied for an efficient DBD plasma generation.

  11. Synthetic tactile perception induced by transcranial alternating-current stimulation can substitute for natural sensory stimulus in behaving rabbits.

    Science.gov (United States)

    Márquez-Ruiz, Javier; Ammann, Claudia; Leal-Campanario, Rocío; Ruffini, Giulio; Gruart, Agnès; Delgado-García, José M

    2016-01-21

    The use of brain-derived signals for controlling external devices has long attracted the attention from neuroscientists and engineers during last decades. Although much effort has been dedicated to establishing effective brain-to-computer communication, computer-to-brain communication feedback for "closing the loop" is now becoming a major research theme. While intracortical microstimulation of the sensory cortex has already been successfully used for this purpose, its future application in humans partly relies on the use of non-invasive brain stimulation technologies. In the present study, we explore the potential use of transcranial alternating-current stimulation (tACS) for synthetic tactile perception in alert behaving animals. More specifically, we determined the effects of tACS on sensory local field potentials (LFPs) and motor output and tested its capability for inducing tactile perception using classical eyeblink conditioning in the behaving animal. We demonstrated that tACS of the primary somatosensory cortex vibrissa area could indeed substitute natural stimuli during training in the associative learning paradigm.

  12. Alternating current electric fields of varying frequencies: effects on proliferation and differentiation of porcine neural progenitor cells.

    Science.gov (United States)

    Lim, Ji-Hey; McCullen, Seth D; Piedrahita, Jorge A; Loboa, Elizabeth G; Olby, Natasha J

    2013-10-01

    Application of sinusoidal electric fields (EFs) has been observed to affect cellular processes, including alignment, proliferation, and differentiation. In the present study, we applied low-frequency alternating current (AC) EFs to porcine neural progenitor cells (pNPCs) and investigated the effects on cell patterning, proliferation, and differentiation. pNPCs were grown directly on interdigitated electrodes (IDEs) localizing the EFs to a region accessible visually for fluorescence-based assays. Cultures of pNPCs were exposed to EFs (1 V/cm) of 1 Hz, 10 Hz, and 50 Hz for 3, 7, and 14 days and compared to control cultures. Immunocytochemistry was performed to evaluate the expression of neural markers. pNPCs grew uniformly with no evidence of alignment to the EFs and no change in cell numbers when compared with controls. Nestin expression was shown in all groups at 3 and 7 days, but not at 14 days. NG2 expression was low in all groups. Co-expression of glial fibrillary acidic protein (GFAP) and TUJ1 was significantly higher in the cultures exposed to 10- and 50-Hz EFs than the controls. In summary, sinusoidal AC EFs via IDEs did not alter the alignment and proliferation of pNPCs, but higher frequency stimulation appeared to delay differentiation into mature astrocytes.

  13. Evaluation of calcium alginate gel as electrode material for alternating current iontophoresis of lidocaine using excised rat skin.

    Science.gov (United States)

    Ebisawa, Tomoko; Nakajima, Atsushi; Haida, Haruka; Wakita, Ryo; Ando, Shizuka; Yoshioka, Tomohiko; Ikoma, Toshiyuki; Tanaka, Junzo; Fukayama, Haruhisa

    2014-06-27

    Iontophoresis (IOP) is a noninvasive method of delivering medication transcutaneously through the skin. The electrodes used in this method should tightly fit to rough and irregular surfaces and be biologically safe, easy to handle and prepare, and cost-effective. To satisfy these requirements, calcium alginate gel can be a candidate electrode for IOP. Using calcium alginate gel electrodes, we examined whether lidocaine can be effectively transported across an excised rat skin by squarewave alternating current (AC) application. A squarewave AC with either a 70% or 80% duty cycle was continuously applied to 0.5% calcium alginate gel electrodes containing 10% lidocaine at 10 V and 1 kHz for 60 min. Lidocaine concentration was measured using a spectrophotometer and the temperature of the gel was determined. The lidocaine concentrations for AC-IOP at the 70% and 80% duty cycles were significantly higher than that without AC-IOP. Furthermore, the group with the 80% duty cycle showed higher lidocaine concentrations than the group with the 70% duty cycle. The temperatures of all the groups were lower than 28 °C throughout the procedure. In conclusion, the calcium alginate gel can be used as a possible matrix for IOP electrodes.

  14. Intermittent Contact Alternating Current Scanning Electrochemical Microscopy: A Method for Mapping Conductivities in Solid Li Ion Conducting Electrolyte Samples

    Energy Technology Data Exchange (ETDEWEB)

    Catarelli, Samantha Raisa; Lonsdale, Daniel [Uniscan Instruments Ltd., Macclesfield (United Kingdom); Cheng, Lei [Energy Storage and Distribution Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Materials Sciences and Engineering Department, University of California Berkeley, Berkeley, CA (United States); Syzdek, Jaroslaw [Bio-Logic USA LLC, Knoxville, TN (United States); Doeff, Marca, E-mail: mmdoeff@lbl.gov [Energy Storage and Distribution Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA (United States)

    2016-03-31

    Intermittent contact alternating current scanning electrochemical microscopy (ic-ac-SECM) has been used to determine the electrochemical response to an ac signal of several types of materials. A conductive gold foil and insulating Teflon sheet were first used to demonstrate that the intermittent contact function allows the topography and conductivity to be mapped simultaneously and independently in a single experiment. Then, a dense pellet of an electronically insulating but Li ion conducting garnet phase, Al-substituted Li{sub 7}La{sub 3}Zr{sub 2}O{sub 12} (LLZO), was characterized using the same technique. The polycrystalline pellet was prepared by classical ceramic sintering techniques and was comprised of large (~150 μm) grains. Critical information regarding the contributions of grain and grain boundary resistances to the total conductivity of the garnet phase was lacking due to ambiguities in the impedance data. In contrast, the use of the ic-ac-SECM technique allowed spatially resolved information regarding local conductivities to be measured directly. Impedance mapping of the pellet showed that the grain boundary resistance, while generally higher than that of grains, varied considerably, revealing the complex nature of the LLZO sample.

  15. Differential effects of 10-Hz and 40-Hz transcranial alternating current stimulation (tACS) on endogenous versus exogenous attention.

    Science.gov (United States)

    Hopfinger, Joseph B; Parsons, Jonathan; Fröhlich, Flavio

    2017-04-01

    Previous electrophysiological studies implicate both alpha (8-12 Hz) and gamma (>30 Hz) neural oscillations in the mechanisms of selective attention. Here, participants preformed two separate visual attention tasks, one endogenous and one exogenous, while transcranial alternating current stimulation (tACS), at 10 Hz, 40 Hz, or sham, was applied to the right parietal lobe. Our results provide new evidence for the roles of gamma and alpha oscillations in voluntary versus involuntary shifts of attention. Gamma (40 Hz) stimulation resulted in improved disengagement from invalidly cued targets in the endogenous attention task, whereas alpha stimulation (10 Hz) had no effect on endogenous attention, but increased the exogenous cuing effect. These findings agree with previous studies suggesting that right inferior parietal regions may be especially important for the disengagement of attention, and go further to provide details about the specific type of oscillatory neural activity within that brain region that is differentially involved in endogenous versus exogenous attention. Our results also have potential implications for the plasticity and training of attention systems.

  16. What Do We Know About the Influence of the Cerebellum on Walking Ability? Promising Findings from Transcranial Alternating Current Stimulation.

    Science.gov (United States)

    Naro, Antonino; Milardi, Demetrio; Cacciola, Alberto; Russo, Margherita; Sciarrone, Francesca; La Rosa, Gianluca; Bramanti, Alessia; Bramanti, Placido; Calabrò, Rocco Salvatore

    2017-08-01

    Several cerebellar functions related to upper limb motor control have been studied using non-invasive brain stimulation paradigms. We have recently shown that transcranial alternating current stimulation (tACS) may be a promising approach in shaping the plasticity of cerebellum-brain pathways in a safe and effective manner. This study aimed to assess whether cerebellar tACS at different frequencies may tune M1-leg excitability and modify gait control in healthy human subjects. To this end, we tested the effects of different cerebellar tACS frequencies over the right cerebellar hemisphere (at 10, 50, and 300 Hz, besides a sham-tACS) on M1-leg excitability, cerebellum-brain inhibition (CBI), and gait parameters in a sample of 25 healthy volunteers. Fifty and 300 Hz tACS differently modified M1-leg excitability and CBI from both lower limbs, without significant gait perturbations. We hypothesize that tACS aftereffect may depend on a selective entrainment of distinct cerebellar networks related to lower limb motor functions. Therefore, cerebellar tACS might represent a useful tool to modulate walking training in people with cerebellum-related gait impairment, given that tACS may potentially reset abnormal cerebellar circuitries.

  17. Preparation of Janus Particles and Alternating Current Electrokinetic Measurements with a Rapidly Fabricated Indium Tin Oxide Electrode Array.

    Science.gov (United States)

    Chen, Yu-Liang; Jiang, Hong-Ren

    2017-06-23

    This article provides a simple method to prepare partially or fully coated metallic particles and to perform the rapid fabrication of electrode arrays, which can facilitate electrical experiments in microfluidic devices. Janus particles are asymmetric particles that contain two different surface properties on their two sides. To prepare Janus particles, a monolayer of silica particles is prepared by a drying process. Gold (Au) is deposited on one side of each particle using a sputtering device. The fully coated metallic particles are completed after the second coating process. To analyze the electrical surface properties of Janus particles, alternating current (AC) electrokinetic measurements, such as dielectrophoresis (DEP) and electrorotation (EROT)- which require specifically designed electrode arrays in the experimental device- are performed. However, traditional methods to fabricate electrode arrays, such as the photolithographic technique, require a series of complicated procedures. Here, we introduce a flexible method to fabricate a designed electrode array. An indium tin oxide (ITO) glass is patterned by a fiber laser marking machine (1,064 nm, 20 W, 90 to 120 ns pulse-width, and 20 to 80 kHz pulse repetition frequency) to create a four-phase electrode array. To generate the four-phase electric field, the electrodes are connected to a 2-channel function generator and to two invertors. The phase shift between the adjacent electrodes is set at either 90° (for EROT) or 180° (for DEP). Representative results of AC electrokinetic measurements with a four-phase ITO electrode array are presented.

  18. Force transmissibility versus displacement transmissibility

    Science.gov (United States)

    Lage, Y. E.; Neves, M. M.; Maia, N. M. M.; Tcherniak, D.

    2014-10-01

    It is well-known that when a single-degree-of-freedom (sdof) system is excited by a continuous motion of the foundation, the force transmissibility, relating the force transmitted to the foundation to the applied force, equals the displacement transmissibility. Recent developments in the generalization of the transmissibility to multiple-degree-of-freedom (mdof) systems have shown that similar simple and direct relations between both types of transmissibility do not appear naturally from the definitions, as happens in the sdof case. In this paper, the authors present their studies on the conditions under which it is possible to establish a relation between force transmissibility and displacement transmissibility for mdof systems. As far as the authors are aware, such a relation is not currently found in the literature, which is justified by being based on recent developments in the transmissibility concept for mdof systems. Indeed, it does not appear naturally, but the authors observed that the needed link is present when the displacement transmissibility is obtained between the same coordinates where the applied and reaction forces are considered in the force transmissibility case; this implies that the boundary conditions are not exactly the same and instead follow some rules. This work presents a formal derivation of the explicit relation between the force and displacement transmissibilities for mdof systems, and discusses its potential and limitations. The authors show that it is possible to obtain the displacement transmissibility from measured forces, and the force transmissibility from measured displacements, opening new perspectives, for example, in the identification of applied or transmitted forces. With this novel relation, it becomes possible, for example, to estimate the force transmissibility matrix with the structure off its supports, in free boundary conditions, and without measuring the forces. As far as force identification is concerned, this

  19. Determination of High-Frequency Current Distribution Using EMTP-Based Transmission Line Models with Resulting Radiated Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Mork, B; Nelson, R; Kirkendall, B; Stenvig, N

    2009-11-30

    Application of BPL technologies to existing overhead high-voltage power lines would benefit greatly from improved simulation tools capable of predicting performance - such as the electromagnetic fields radiated from such lines. Existing EMTP-based frequency-dependent line models are attractive since their parameters are derived from physical design dimensions which are easily obtained. However, to calculate the radiated electromagnetic fields, detailed current distributions need to be determined. This paper presents a method of using EMTP line models to determine the current distribution on the lines, as well as a technique for using these current distributions to determine the radiated electromagnetic fields.

  20. 76 FR 79206 - Commercial Renewable Energy Transmission on the Outer Continental Shelf (OCS) Offshore Mid...

    Science.gov (United States)

    2011-12-21

    ...-circuit, high-voltage direct current (HVDC) transmission line that would collect power generated by wind...-voltage alternating current into HVDC using voltage sourced converters. Each offshore converter platform... transmission grid at up to seven locations where AWC terrestrial converter stations would convert the HVDC...

  1. Chagas disease: current epidemiological trends after the interruption of vectorial and transfusional transmission in the Southern Cone countries.

    Science.gov (United States)

    Moncayo, Alvaro

    2003-07-01

    Chagas disease, named after Carlos Chagas who first described it in 1909, exists only on the American Continent. It is caused by a parasite, Trypanosoma cruzi, transmitted to humans by blood-sucking triatomine bugs and by blood transfusion. Chagas disease has two successive phases, acute and chronic. The acute phase lasts 6 to 8 weeks. After several years of starting the chronic phase, 20% to 35% of the infected individuals, depending on the geographical area will develop irreversible lesions of the autonomous nervous system in the heart, esophagus, colon and the peripheral nervous system. Data on the prevalence and distribution of Chagas disease improved in quality during the 1980's as a result of the demographically representative cross-sectional studies carried out in countries where accurate information was not available. A group of experts met in Bras lia in 1979 and devised standard protocols to carry out countrywide prevalence studies on human T. cruzi infection and triatomine house infestation. Thanks to a coordinated multi-country program in the Southern Cone countries the transmission of Chagas disease by vectors and by blood transfusion has been interrupted in Uruguay in1997, in Chile in 1999, and in 8 of the 12 endemic states of Brazil in 2000 and so the incidence of new infections by T. cruzi in the whole continent has decreased by 70%. Similar control multi-country initiatives have been launched in the Andean countries and in Central America and rapid progress has been recorded to ensure the interruption of the transmission of Chagas disease by 2005 as requested by a Resolution of the World Health Assembly approved in 1998. The cost-benefit analysis of the investments of the vector control program in Brazil indicate that there are savings of US$17 in medical care and disabilities for each dollar spent on prevention, showing that the program is a health investment with good return. Since the inception in 1979 of the Steering Committee on Chagas Disease

  2. Current knowledge of sand fly fauna (Diptera: Psychodidae) of northwestern Yemen and how it relates to leishmaniasis transmission.

    Science.gov (United States)

    El Sawaf, Bahira M; Kassem, Hala A; Mogalli, Nabil M; El Hossary, Shabaan S; Ramadan, Nadia F

    2016-10-01

    This report presents the results of the first entomological survey of the sand fly fauna in northwestern Yemen. Sand flies were collected using sticky paper traps and CDC light traps from Hajjah governorate, a cutaneous leishmaniasis focus due to Leishmania tropica. Six Phlebotomus species: P. alexandri, P. arabicus. P. bergeroti, P. orientalis, P. papatasi, P. sergenti and ten Sergentomyia species: S. africana, S. antennata, S. christophersi, S. dolichopa, S. dreyfussi, S. fallax, S. multidens, S. taizi, S. tiberiadis, S. yusafi were identified. P. alexandri was the most predominant Phlebotomus species and P. papatasi was a scarce species. S. fallax was the principal Sergentomyia species and S. dolichopa was the least species encountered. The diversity of the sand fly fauna within and among three altitudinal ranges using Simpson index and Jaccard's diversity coefficient respectively were measured. High species diversity was found in all altitude ranges. There seemed to be more association between sand fly fauna in higher altitudes with fauna from moderate altitudes. Sand fly seasonal activity showed a mono-modal trend in the lowland and a confluent bimodal trend in the highlands. Leishmania DNA could not be detected from 150 Phlebotomus females using PCR-RFLP. A possible zoonotic cutaneous transmission cycle due to Leishmania tropica in northwestern Yemen would involve P. arabicus as the sand fly vector and the rock hyrax as the reservoir host. The vector competence for P. alexandri as a vector of visceral leishmaniasis in Hajjah governorate is discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. HIV Mother-to-Child Transmission, Mode of Delivery, and Duration of Rupture of Membranes: Experience in the Current Era

    Directory of Open Access Journals (Sweden)

    Siobhan Mark

    2012-01-01

    Full Text Available Objective. To evaluate whether the length of time of rupture of membranes (ROM in optimally managed HIV-positive women on highly active antiretroviral therapy (HAART with low viral loads (VL is predictive of the risk of mother to child transmission (MTCT of the human immunodeficiency virus (HIV. Study Methods. A retrospective case series of all HIV-positive women who delivered at two academic tertiary centers in Toronto, Canada from January 2000 to November 2010 was completed. Results. Two hundred and ten HIV-positive women with viral loads <1,000 copies/ml delivered during the study period. VL was undetectable (<50 copies/mL for the majority of the women (167, 80%, and <1,000 copies/mL for all women. Mode of delivery was vaginal in 107 (51% and cesarean in 103 (49%. The median length of time of ROM was 0.63 hours (range 0 to 77.87 hours for the entire group and 2.56 hours (range 0 to 53.90 hours for those who had a vaginal birth. Among women with undetectable VL, 90 (54% had a vaginal birth and 77 (46% had a cesarean birth. Among the women in this cohort there were no cases of MTCT of HIV. Conclusions. There was no association between duration of ROM or mode of delivery and MTCT in this cohort of 210 virally suppressed HIV-positive pregnant women.

  4. Complementary and Alternative Medicine: Comparison of Current Knowledge, Attitudes and Interest among German Medical Students and Doctors

    Directory of Open Access Journals (Sweden)

    Karsten Münstedt

    2011-01-01

    Full Text Available Although it has been agreed that complementary and alternative medicine (CAM should be included in the German medical curriculum, there is no consensus on which methods and how it should be taught. This study aimed to assess needs for CAM education by evaluating current knowledge, attitudes and interests of medical students, general physicians and gynecologists. Two instruments based on established and validated questionnaires were developed. One was given to seventh semester medical students and the other to office-based doctors. Data were analyzed by bivariate correlation and cross-tabulation. Altogether 550 questionnaires were distributed—280 to doctors and 270 to medical students. Completed questionnaires were returned by 80.4% of students and 78.2% of doctors. Although 73.8% (160/219 of doctors and 40% (87/217 of students had already informed themselves about CAM, neither group felt that they knew much about CAM. Doctors believed that CAM was most useful in general medicine, supportive oncology, pediatrics, dermatology and gynecology, while students believed that dermatology, general medicine, psychiatry and rheumatology offered opportunities; both recommended that CAM should be taught in these areas. Both groups believed that CAM should be included in medical education; however, they believed that CAM needed more investigation and should be taught “critically". German doctors and students would like to be better informed about CAM. An approach which teaches fundamental competences to students, chooses specific content based on evidence, demographics and medical conditions and provides students with the skills they need for future learning should be adopted.

  5. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation.

    Science.gov (United States)

    Vosskuhl, Johannes; Huster, René J; Herrmann, Christoph S

    2015-01-01

    Working memory (WM) and short-term memory (STM) supposedly rely on the phase-amplitude coupling (PAC) of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual's memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS). To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N = 33) were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG) was measured before stimulation and analyzed with regard to the properties of PAC between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  6. Increase in short-term memory capacity induced by down-regulating individual theta frequency via transcranial alternating current stimulation

    Directory of Open Access Journals (Sweden)

    Johannes eVosskuhl

    2015-05-01

    Full Text Available Working memory (WM and short-term memory (STM supposedly rely on the phase-amplitude coupling of neural oscillations in the theta and gamma frequency ranges. The ratio between the individually dominant gamma and theta frequencies is believed to determine an individual’s memory capacity. The aim of this study was to establish a causal relationship between the gamma/theta ratio and WM/STM capacity by means of transcranial alternating current stimulation (tACS. To achieve this, tACS was delivered at a frequency below the individual theta frequency. Thereby the individual ratio of gamma to theta frequencies was changed, resulting in an increase of STM capacity. Healthy human participants (N=33 were allocated to two groups, one receiving verum tACS, the other underwent a sham control protocol. The electroencephalogram (EEG was measured before stimulation and analyzed with regard to the properties of phase-amplitude coupling between theta and gamma frequencies to determine individual stimulation frequencies. After stimulation, EEG was recorded again in order to find after-effects of tACS in the oscillatory features of the EEG. Measures of STM and WM were obtained before, during and after stimulation. Frequency spectra and behavioral data were compared between groups and different measurement phases. The tACS- but not the sham stimulated group showed an increase in STM capacity during stimulation. WM was not affected in either groups. An increase in task-related theta amplitude after stimulation was observed only for the tACS group. These augmented theta amplitudes indicated that the manipulation of individual theta frequencies was successful and caused the increase in STM capacity.

  7. The Way of Reducing Current Values in Optical Ground Wires at Asymmetrical Faults on Overhead Transmission Lines

    Directory of Open Access Journals (Sweden)

    Egamnazarov Georgiy

    2016-12-01

    Full Text Available Given the fact that the installing costs of an optical ground wire on overhead lines directly depend on its cross-section, which in turn depends on the level of fault current it should withstand, in order to reduce these current values in the optical ground wire, I suggested performing its isolated descents from the end towers of the line with its transition to an optical cable. The research was carried out on the example of a 500 kV overhead line in the National Electric Power Grid. The Method of Symmetrical Components for calculating asymmetrical fault currents was not used; therefore, calculations were carried out on the base of presenting the line as a multi-wire system for the considered case as a five-wire system (optical ground wire, steel ground wire, and three phase wires. Such approach allows taking into account the initial asymmetry of the line parameters and modeling any kind of asymmetrical faults. The analyses of calculated results were performed. The conclusive evidence that the optical ground wire isolated descents from the end towers of the line give the possibility of reducing the level of maximal fault current distribution values in it and therefore its cross section, is presented.

  8. Energy saving based on the reduction of losses in the transmission and distribution of the power generated incrementing the transmission capacities by means of the use of direct current; Ahorro de energia basado en la reduccion de perdidas en la transmision y redistribucion de la generacion al ampliar las capacidades de transmision por medio del empleo de la transmision en corriente directa

    Energy Technology Data Exchange (ETDEWEB)

    Meraz Ateca, E.; Alanis Rodriguez, J.P.; Salinas Barrera, H.; Arechiga Rodriguez, L.D.; Guerrero Garza, J.J. [Comision Federal de Electricidad (CFE) (Mexico)

    1995-12-31

    alternating current terminal is recovered from the power lines and there will not be generation restrictions because of the unavailability of alternating current power lines; the achieved reliability is not evaluated, but it will be another benefit. The other option proposed for the project of utilization of power lines with direct current, consists in modifying or using the tie that will be constructed for the Rio Escondido Thermal Electric Station to the Northern Zone and that will operate in parallel with the alternating current network. This project provides the benefits of saving losses of about 20 MW. It is also achieved the increase in effective transmission capacity towards the Northern Zone, due to the fact that it will be Also available a controlled power mean, which facilitates the dispatch functions and re-distribution of power flows in the alternating current network. This tie is proposed of 500 MW operating in bi-polar form at least of 400 KV and reaching up to the Chihuahua Zone, allowing besides the re-dispatching of units to the Northern Zone in counting with greater capacity of effective transmission. The saving in re-dispatching could be significative; additionally, this tie will free transmission capacity from the Coal Power Stations towards the Monterrey Zone. This paper does not get deeper into the advantages regarding the dynamic behavior of the electric system in operating these ties in direct current, but they are not less important, since they can contribute with great benefits to the system during disturbance or emergency conditions. [Espanol] El presenta trabajo propone el empleo de la tecnologia de transmision en corriente directa, que proporciona un ahorro de perdidas de orden del 50% al transmitir la misma cantidad de potencia que la linea energizada en corriente alterna, asi como el contar con una mayor capacidad de transmision, dado que la limitante en la linea trabajando en corriente directa esta dada por su capacidad termica. El aspecto del

  9. Energy saving based on the reduction of losses in the transmission and distribution of the power generated incrementing the transmission capacities by means of the use of direct current; Ahorro de energia basado en la reduccion de perdidas en la transmision y redistribucion de la generacion al ampliar las capacidades de transmision por medio del empleo de la transmision en corriente directa

    Energy Technology Data Exchange (ETDEWEB)

    Meraz Ateca, E; Alanis Rodriguez, J P; Salinas Barrera, H; Arechiga Rodriguez, L D; Guerrero Garza, J J [Comision Federal de Electricidad (CFE) (Mexico)

    1996-12-31

    alternating current terminal is recovered from the power lines and there will not be generation restrictions because of the unavailability of alternating current power lines; the achieved reliability is not evaluated, but it will be another benefit. The other option proposed for the project of utilization of power lines with direct current, consists in modifying or using the tie that will be constructed for the Rio Escondido Thermal Electric Station to the Northern Zone and that will operate in parallel with the alternating current network. This project provides the benefits of saving losses of about 20 MW. It is also achieved the increase in effective transmission capacity towards the Northern Zone, due to the fact that it will be Also available a controlled power mean, which facilitates the dispatch functions and re-distribution of power flows in the alternating current network. This tie is proposed of 500 MW operating in bi-polar form at least of 400 KV and reaching up to the Chihuahua Zone, allowing besides the re-dispatching of units to the Northern Zone in counting with greater capacity of effective transmission. The saving in re-dispatching could be significative; additionally, this tie will free transmission capacity from the Coal Power Stations towards the Monterrey Zone. This paper does not get deeper into the advantages regarding the dynamic behavior of the electric system in operating these ties in direct current, but they are not less important, since they can contribute with great benefits to the system during disturbance or emergency conditions. [Espanol] El presenta trabajo propone el empleo de la tecnologia de transmision en corriente directa, que proporciona un ahorro de perdidas de orden del 50% al transmitir la misma cantidad de potencia que la linea energizada en corriente alterna, asi como el contar con una mayor capacidad de transmision, dado que la limitante en la linea trabajando en corriente directa esta dada por su capacidad termica. El aspecto del

  10. Comparison of PI and PR current controllers applied on two-level VSC-HVDC transmission system

    DEFF Research Database (Denmark)

    Manoloiu, A.; Pereria, H.A.; Teodorescu, Remus

    2015-01-01

    This paper analyzes differences between αβ and dq reference frames regarding the control of two-level VSC-HVDC current loop and dc-link voltage outer loop. In the first part, voltage feedforward effect is considered with PI and PR controllers. In the second part, the feedforward effect is removed...... and the PR gains are tuned to keep the dynamic performance. Also, the power feedforward is removed and the outer loop PI controller is tuned in order to maintain the system dynamic performance. The paper is completed with simulation results, which highlight the advantages of using PR controller....

  11. Geomanetically Induced Currents (GIC) calculation, impact assessment on transmission system and validation using 3-D earth conductivity tensors and GIC measurements.

    Science.gov (United States)

    Sharma, R.; McCalley, J. D.

    2016-12-01

    Geomagnetic disturbance (GMD) causes the flow of geomagnetically induced currents (GIC) in the power transmission system that may cause large scale power outages and power system equipment damage. In order to plan for defense against GMD, it is necessary to accurately estimate the flow of GICs in the power transmission system. The current calculation as per NERC standards uses the 1-D earth conductivity models that don't reflect the coupling between the geoelectric and geomagnetic field components in the same direction. For accurate estimation of GICs, it is important to have spatially granular 3-D earth conductivity tensors, accurate DC network model of the transmission system and precisely estimated or measured input in the form of geomagnetic or geoelectric field data. Using these models and data the pre event, post event and online planning and assessment can be performed. The pre, post and online planning can be done by calculating GIC, analyzing voltage stability margin, identifying protection system vulnerabilities and estimating heating in transmission equipment. In order to perform the above mentioned tasks, an established GIC calculation and analysis procedure is needed that uses improved geophysical and DC network models obtained by model parameter tuning. The issue is addressed by performing the following tasks; 1) Geomagnetic field data and improved 3-D earth conductivity tensors are used to plot the geoelectric field map of a given area. The obtained geoelectric field map then serves as an input to the PSS/E platform, where through DC circuit analysis the GIC flows are calculated. 2) The computed GIC is evaluated against GIC measurements in order to fine tune the geophysical and DC network model parameters for any mismatch in the calculated and measured GIC. 3) The GIC calculation procedure is then adapted for a one in 100 year storm, in order to assess the impact of the worst case GMD on the power system. 4) Using the transformer models, the voltage

  12. RF high voltage performance of RF transmission line components on the DIII-D Fast Wave Current Drive (FWCD) system

    International Nuclear Information System (INIS)

    Ferguson, S.W.; Callis, R.W.; Cary, W.P.; Phelps, D.A.; Ponce, D.; Baity, F.W.; Barber, G.

    1995-01-01

    The performance of the high voltage rf components of the DIII-D Fast Wave Current Drive System (FWCD) have been evaluated under various conditions of insulator configuration, insulator material, insulating gas and gas pressure. The insulator materials that have been investigated are alumina, steatite, pyrex, quartz, and teflon. The results of this evaluation are discussed in this paper. Additionally a rf high potter was developed to aid in the evaluation of rf high voltage components. The high potter consists of a 50 Ω, 1/4 wavelength cavity with a variable position short and a 50 ohm matched tap at one end of the cavity. With this configuration rf voltages were generated in excess of 100 kVp in the frequency range 30 to 60 MHz

  13. RF high voltage performance of RF transmission line components on the DIII-D Fast Wave Current Drive (FWCD) System

    International Nuclear Information System (INIS)

    Ferguson, S.W.; Callis, R.W.; Cary, W.P.; Phelps, D.A.; Ponce, D.; Baity, F.W.; Barber, G.

    1995-12-01

    The performance of the high voltage rf components of the DIII-D Fast Wave Current Drive System (FWCD) have been evaluated under various conditions of insulator configuration, insulator material, insulating gas and gas pressure. The insulator materials that have been investigated are alumina, steatite, pyrex, quartz, and teflon. The results of this evaluation are discussed in this paper. Additionally a rf high potter was developed to aid in the evaluation of rf high voltage components. The high potter consists of a 50 Ω, 1/4 wavelength cavity with a variable position short and a 50 ohm matched tap at one end of the cavity. With this configuration rf voltages were generated in excess of 100 kVp in the frequency range 30 to 60 MHz

  14. Signature of the Collaboration agreement contract between CERN and IASS on High Current, Long Distance Superconducting Power Transmission Lines signed Dr.Steve Myers Director of Acc Tech and Prof. Carlo Rubbia.

    CERN Multimedia

    Maximilien Brice

    2012-01-01

    Signature of the Collaboration agreement contract between CERN and IASS on High Current, Long Distance Superconducting Power Transmission Lines signed Dr.Steve Myers Director of Acc Tech and Prof. Carlo Rubbia.

  15. Donor testing and risk: current prevalence, incidence, and residual risk of transfusion-transmissible agents in US allogeneic donations.

    Science.gov (United States)

    Zou, Shimian; Stramer, Susan L; Dodd, Roger Y

    2012-04-01

    Over the past 20 years, there has been a major increase in the safety of the blood supply, as demonstrated by declining rates of posttransfusion infection and reductions in estimated residual risk for such infections. Reliable estimates of residual risk have been possible within the American Red Cross system because of the availability of a large amount of reliable and consistent data on donations and infectious disease testing results. Among allogeneic blood donations, the prevalence rates of infection markers for hepatitis C virus (HCV) and hepatitis B virus have decreased over time, although rates for markers of human immunodeficiency virus (HIV) and human T-cell lymphotropic virus did not. The incidence (/100 000 person-years) of HIV and HCV among repeat donors showed apparent increases from 1.55 and 1.89 in 2000 through 2001 to 2.16 and 2.98 in 2007 through 2008. These observed fluctuations confirm the need for continuous monitoring and evaluation. The residual risk of HIV, HCV, and human T-cell lymphotropic virus among all allogeneic donations is currently below 1 per 1 million donations, and that of hepatitis B surface antigen is close to 1 per 300 000 donations. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Survey of Spread and Reasons of Turning into Alternative Therapies to Current Medicine: (Case Study of Tehran

    Directory of Open Access Journals (Sweden)

    Reihaneh Ramezani

    2017-09-01

    Conclusions: Although the reasons of citizens for using alternative therapies was more pragmatic, but statistical analysis showed that near 40% of the variance of using Herbal treatment among citizens interested by awareness about benefits of this therapy in advices of religious leaders.

  17. Avian mortalities due to transmission line collisions: a review of current estimates and field methods with an emphasis on applications to the Canadian electric network

    Directory of Open Access Journals (Sweden)

    Sébastien Rioux

    2013-12-01

    Full Text Available Birds are vulnerable to collisions with human-made fixed structures. Despite ongoing development and increases in infrastructure, we have few estimates of the magnitude of collision mortality. We reviewed the existing literature on avian mortality associated with transmission lines and derived an initial estimate for Canada. Estimating mortality from collisions with power lines is challenging due to the lack of studies, especially from sites within Canada, and due to uncertainty about the magnitude of detection biases. Detection of bird collisions with transmission lines varies due to habitat type, species size, and scavenging rates. In addition, birds can be crippled by the impact and subsequently die, although crippling rates are poorly known and rarely incorporated into estimates. We used existing data to derive a range of estimates of avian mortality associated with collisions with transmission lines in Canada by incorporating detection, scavenging, and crippling biases. There are 231,966 km of transmission lines across Canada, mostly in the boreal forest. Mortality estimates ranged from 1 million to 229.5 million birds per year, depending on the bias corrections applied. We consider our most realistic estimate, taking into account variation in risk across Canada, to range from 2.5 million to 25.6 million birds killed per year. Data from multiple studies across Canada and the northern U.S. indicate that the most vulnerable bird groups are (1 waterfowl, (2 grebes, (3 shorebirds, and (4 cranes, which is consistent with other studies. Populations of several groups that are vulnerable to collisions are increasing across Canada (e.g., waterfowl, raptors, which suggests that collision mortality, at current levels, is not limiting population growth. However, there may be impacts on other declining species, such as shorebirds and some species at risk, including Alberta's Trumpeter Swans (Cygnus buccinator and western Canada's endangered Whooping

  18. Natural Leishmania (Viannia) infections of phlebotomines (Diptera: Psychodidae) indicate classical and alternative transmission cycles of American cutaneous leishmaniasis in the Guiana Shield, Brazil.

    Science.gov (United States)

    de Souza, Adelson Alcimar Almeida; da Rocha Barata, Iorlando; das Graças Soares Silva, Maria; Lima, José Aprígio Nunes; Jennings, Yara Lúcia Lins; Ishikawa, Edna Aoba Yassui; Prévot, Ghislaine; Ginouves, Marine; Silveira, Fernando Tobias; Shaw, Jeffrey; Dos Santos, Thiago Vasconcelos

    2017-01-01

    From 1996 to 1999 multi-trapping methods (Center of Diseases Control, CDC) light traps, light-baited Shannon traps, and aspiration on tree bases) were used to study the phlebotomine fauna of the "Serra do Navio" region of the Brazilian State of Amapá, which is part of the Guiana Shield. Fifty-three species were identified among 8,685 captured individuals. The following species, associated with the transmission of American cutaneous leishmaniasis in Amazonian Brazil, were captured: Nyssomyia umbratilis (3,388), Psychodopygus squamiventris maripaensis (995), Ny. anduzei (550), Trichophoromyia ubiquitalis (400), Ny. whitmani (291), Ps. paraensis (116), and Bichromomyia flaviscutellata (50). Flagellate infections were detected in 45 flies. Of the 19 parasites isolated in vitro, 15 were Leishmania (Viannia) guyanensis (13 in Ny. umbratilis, 1 in Ny. whitmani, 1 in Ny. anduzei) and three were L. (V.) naiffi (2 in Ps. s. maripaensis, 1 in Ny. anduzei). The results indicate the participation of three phlebotomine species in the transmission of L. (V.) guyanensis and two species in that of L. (V.) naiffi, and show that the same phlebotomine species is involved in the transmission of different Leishmania (Viannia) species in the Guianan/Amazon region. A review of the literature together with the results of the present study, and other published and unpublished results, indicate that eight phlebotomine species potentially participate in the transmission of Leishmania (Viannia) naiffi in Amazonia. © A.A.A. de Souza et al., published by EDP Sciences, 2017.

  19. Measuring population transmission risk for HIV: an alternative metric of exposure risk in men who have sex with men (MSM in the US.

    Directory of Open Access Journals (Sweden)

    Colleen F Kelley

    Full Text Available Various metrics for HIV burden and treatment success [e.g. HIV prevalence, community viral load (CVL, population viral load (PVL, percent of HIV-positive persons with undetectable viral load] have important public health limitations for understanding disparities.Using data from an ongoing HIV incidence cohort of black and white men who have sex with men (MSM, we propose a new metric to measure the prevalence of those at risk of transmitting HIV and illustrate its value. MSM with plasma VL>400 copies/mL were defined as having 'transmission risk'. We calculated HIV prevalence, CVL, PVL, percent of HIV-positive with undetectable viral loads, and prevalence of plasma VL>400 copies/ml (%VL400 for black and white MSM. We used Monte Carlo simulation incorporating data on sexual mixing by race to estimate exposure of black and white HIV-negative MSM to a partner with transmission risk via unprotected anal intercourse (UAI. Of 709 MSM recruited, 42% (168/399 black and 14% (44/310 white MSM tested HIV-positive (p<.0001. No significant differences were seen in CVL, PVL, or percent of HIV positive with undetectable viral loads. The %VL400 was 25% (98/393 for black vs. 8% (25/310 for white MSM (p<.0001. Black MSM with 2 UAI partners were estimated to have 40% probability (95% CI: 35%, 45% of having ≥1 UAI partner with transmission risk vs. 20% for white MSM (CI: 15%, 24%.Despite similarities in other metrics, black MSM in our cohort are three times as likely as white MSM to have HIV transmission risk. With comparable risk behaviors, HIV-negative black MSM have a substantially higher likelihood of encountering a UAI partner at risk of transmitting HIV. Our results support increasing HIV testing, linkage to care, and antiretroviral treatment of HIV-positive MSM to reduce prevalence of those with transmission risk, particularly for black MSM.

  20. High Voltage Resistive Divider Based on Cast Microwire in Glass Insulation on 6–24 kV Alternating Current of Commercial Frequency.

    Directory of Open Access Journals (Sweden)

    Juravleov A.

    2008-12-01

    Full Text Available It is presented the analysis and description of the construction of the high voltage resistive divider on the base of cast microwire in glass insulation on 6–24 kV alternating current of commercial frequency. It is presented the procedure of compensation of frequency error during the process of fabrication of divides and results of tests of the sample model of the divider as well.

  1. Use of new technologies in the solution of concrete problems in the national transmission system

    International Nuclear Information System (INIS)

    Martinez Gil, Javier

    2007-01-01

    As part of the elaboration of the expansion plan of the national transmission system, the UPME carries out analysis that contribute in the good and efficient use of this system, its amplification and correction of its weaknesses, for they revised it the state of the art of the flexible systems of transmission of alternating current and carry out preliminary analysis of its application

  2. Numerical and theoretical evaluations of AC losses for single and infinite numbers of superconductor strips with direct and alternating transport currents in external AC magnetic field

    Science.gov (United States)

    Kajikawa, K.; Funaki, K.; Shikimachi, K.; Hirano, N.; Nagaya, S.

    2010-11-01

    AC losses in a superconductor strip are numerically evaluated by means of a finite element method formulated with a current vector potential. The expressions of AC losses in an infinite slab that corresponds to a simple model of infinitely stacked strips are also derived theoretically. It is assumed that the voltage-current characteristics of the superconductors are represented by Bean's critical state model. The typical operation pattern of a Superconducting Magnetic Energy Storage (SMES) coil with direct and alternating transport currents in an external AC magnetic field is taken into account as the electromagnetic environment for both the single strip and the infinite slab. By using the obtained results of AC losses, the influences of the transport currents on the total losses are discussed quantitatively.

  3. Borrelia burgdorferi requires the alternative sigma factor RpoS for dissemination within the vector during tick-to-mammal transmission.

    Directory of Open Access Journals (Sweden)

    Star M Dunham-Ems

    2012-02-01

    Full Text Available While the roles of rpoS(Bb and RpoS-dependent genes have been studied extensively within the mammal, the contribution of the RpoS regulon to the tick-phase of the Borrelia burgdorferi enzootic cycle has not been examined. Herein, we demonstrate that RpoS-dependent gene expression is prerequisite for the transmission of spirochetes by feeding nymphs. RpoS-deficient organisms are confined to the midgut lumen where they transform into an unusual morphotype (round bodies during the later stages of the blood meal. We show that round body formation is rapidly reversible, and in vitro appears to be attributable, in part, to reduced levels of Coenzyme A disulfide reductase, which among other functions, provides NAD+ for glycolysis. Our data suggest that spirochetes default to an RpoS-independent program for round body formation upon sensing that the energetics for transmission are unfavorable.

  4. Alternating current losses of a 10 metre long low loss superconducting cable conductor determined from phase sensitive measurements

    International Nuclear Information System (INIS)

    Krueger Olsen, S.; Kuehle, A.; Traeholt, C.; C Rasmussen, C.; Toennesen, O.; Daeumling, M.; Rasmussen, C.N.; Willen, D.W.A.

    1999-01-01

    The ac loss of a superconducting cable conductor carrying an ac current is small. Therefore the ratio between the inductive (out-of-phase) and the resistive (in-phase) voltages over the conductor is correspondingly high. In vectorial representations this results in phase angles between the current and the voltage over the cable close to 90 degrees. This has the effect that the loss cannot be derived directly using most commercial lock-in amplifiers due to their limited absolute accuracy. However, by using two lock-in amplifiers and an appropriate correction scheme the high relative accuracy of such lock-in amplifiers can be exploited. In this paper we present the results from ac-loss measurements on a low loss 10 metre long high temperature superconducting cable conductor using such a correction scheme. Measurements were carried out with and without a compensation circuit that could reduce the inductive voltage. The 1 μV cm -1 critical current of the conductor was 3240 A at 77 K. At an rms current of 2 kA (50 Hz) the ac loss was derived to be 0.6±0.15 W m -1 . This is, to the best of our knowledge, the lowest value of ac loss of a high temperature superconducting cable conductor reported so far at these high currents. (author)

  5. An EIS alternative for impedance measurement of a high temperature PEM fuel cell stack based on current pulse injection

    DEFF Research Database (Denmark)

    Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart

    2017-01-01

    In this paper a method for estimating the fuel cell impedance is presented, namely the current pulse injection (CPI) method, which is well suited for online implementation. This method estimates the fuel cell impedance and unlike electrochemical impedance spectroscopy (EIS), it is simple...... to implement at a low cost. This makes it appealing as a characterization method for on-line diagnostic algorithms. In this work a parameter estimation method for estimation of equivalent electrical circuit (EEC) parameters, which is suited for on-line use is proposed. Tests on a 10 cell high temperature PEM...... fuel cell show that the method yields consistent results in estimating EEC parameters for different current pulse at different current loads, with a low variance. A comparison with EIS shows that despite its simplicity the response of CPI can reproduce well the impedance response of the high...

  6. Current experimental work related to a system alternative to that using the cryogenic separation of hydrogen isotopes

    International Nuclear Information System (INIS)

    Pierini, G.; Spelta, B.; Rizzello, C.

    1985-01-01

    The feasibility study of an alternative exhaust plasma process based mainly on the handling of tritiated waters had shown that it could be competitive as some units used in the isotopic separation system (ISS) could attain the performance required in the conceptual design. In particular, the two cells operating in the ISS should have confirmed, first the high separation factor between protium and tritium found in the literature, second the possibility of working at very low liquid (electrolyte) inventory or, in other words, tritium inventory. Moreover, research has been undertaken in order to investigate the preparation and charcterization of some types of separators which should be resistent to the beta radiation of tritiated water

  7. Transmission policy in Alberta and Bill 50

    International Nuclear Information System (INIS)

    Church, J.; Rosehart, W.; MacCormack, J.

    2009-01-01

    Plans developed by the Alberta Electric System Operator (AESO) have determined that Alberta's electrical transmission system needs to be expanded. However, there are complex issues that must be considered in order to assess the nature and extent of the needed expansion. Various new amendments to the system were proposed in the Alberta government's Bill 50, including the construction of new transmission lines; the installation of a double circuit 500 kV alternating current line between Edmonton and the Gibbons-Redwater region; the construction of a new 240 kV substation in southeast Calgary; and the installation of 2 single circuit 500 kV alternating current lines between Edmonton and Fort McMurray. This study provided a review of the institutional framework instituted by the government's transmission policy and compared the costs and benefits of 2 large capacity high voltage DC (HVDC) transmission lines proposed for the Edmonton-Calgary corridor relative to the various other transmission system amendment suggestions. An evaluation of Alberta's proposed regulatory process under Bill 50 was also conducted. Results of the study indicated that the addition of the HVDC lines is an inefficient response to concerns over adequate supply and reliability. 72 refs., 18 tabs.

  8. Alternating current losses of a 10 metre long low loss superconducting cable conductor determined from phase sensitive measurements

    DEFF Research Database (Denmark)

    Olsen, Søren Krüger; Kühle (fratrådt), Anders Van Der Aa; Træholt, Chresten

    1999-01-01

    The ac loss of a superconducting cable conductor carrying an ac current is small. Therefore the ratio between the inductive (out-of-phase) and the resistive (in-phase) voltages over the conductor is correspondingly high. In vectorial representations this results in phase angles between the current......-in amplifiers can be exploited. In this paper we present the results from ac-loss measurements on a low loss 10 metre long high temperature superconducting cable conductor using such a correction scheme. Measurements were carried out with and without a compensation circuit that could reduce-the inductive...... voltage. The 1 mu V cm(-1) critical current of the conductor was 3240 A at 77 K. At an rms current of 2 kA (50 Hz) the ac loss was derived to be 0.6 +/- 0.15 W m(-1). This is, to the best of our knowledge, the lowest value of ac loss of a high temperature superconducting cable conductor reported so far...

  9. A Study of Second-Year Engineering Students' Alternative Conceptions about Electric Potential, Current Intensity and Ohm's Law

    Science.gov (United States)

    Periago, M. Cristina; Bohigas, Xavier

    2005-01-01

    The aim of this research was to evaluate and analyse second-year industrial engineering and chemical engineering students prior knowledge of conceptual aspects of "circuit theory". Specifically, we focused on the basic concepts of electric potential and current intensity and on the fundamental relationship between them as expressed by Ohm's law.…

  10. On the annealing behaviour of dysprosium ion implanted nickel: a combined study using Rutherford backscattering, transmission electron microscopy, and total current spectroscopy

    International Nuclear Information System (INIS)

    Chadderton, L.T.; Johnson, E.

    1977-01-01

    Despite continuing improvements in applications of the analytical method of Rutherford backscattering (RBS) to solid state physics it is recognized that more complete information can be obtained if other techniques - for example transmission electron microscopy (TEM) - are employed simultaneously. Experiments are described in which a combined RBS and TEM study of the annealing of nickel, rendered amorphous by implantation of 20 keV dysprosium ions is supplemented with a completely new technique - total current spectroscopy (TCS). In TCS low energy electrons (0-15 eV) are used to probe the damaged nickel. Observations have been made during annealing of both the reappearance of the bulk band structure of the metal and of a 'surface peak' which is highly sensitive to the recovery process. Changes in the height of the surface peak reveal three sharp annealing stages, the first two being preceded by reverse annealing which correlates well with RBS and TEM results. The first annealing stage - following the amorphous to crystalline transition - may be associated with electronic effects in the vicinity of the Curie point. Changes in the position of the surface peak allow one to trace the diffusion of dysprosium to the surface. Quantum mechanical resonances at the damage/crystal interface have also been followed throughout annealing. The initially amorphous layer (approximately 2.2nm) increases in thickness slightly during recovery. (Auth.)

  11. Numerical simulations of electric potential field for alternating current potential drop associated with surface cracks in low-alloy steel nuclear material

    Science.gov (United States)

    Yeh, Chun-Ping; Huang, Jiunn-Yuan

    2018-04-01

    Low-alloy steels used as structural materials in nuclear power plants are subjected to cyclic stresses during power plant operations. As a result, cracks may develop and propagate through the material. The alternating current potential drop technique is used to measure the lengths of cracks in metallic components. The depth of the penetration of the alternating current is assumed to be small compared to the crack length. This assumption allows the adoption of the unfolding technique to simplify the problem to a surface Laplacian field. The numerical modelling of the electric potential and current density distribution prediction model for a compact tension specimen and the unfolded crack model are presented in this paper. The goal of this work is to conduct numerical simulations to reduce deviations occurring in the crack length measurements. Numerical simulations were conducted on AISI 4340 low-alloy steel with different crack lengths to evaluate the electric potential distribution. From the simulated results, an optimised position for voltage measurements in the crack region was proposed.

  12. Interrupting transmission of soil-transmitted helminths: a study protocol for cluster randomised trials evaluating alternative treatment strategies and delivery systems in Kenya.

    Science.gov (United States)

    Brooker, Simon J; Mwandawiro, Charles S; Halliday, Katherine E; Njenga, Sammy M; Mcharo, Carlos; Gichuki, Paul M; Wasunna, Beatrice; Kihara, Jimmy H; Njomo, Doris; Alusala, Dorcas; Chiguzo, Athuman; Turner, Hugo C; Teti, Caroline; Gwayi-Chore, Claire; Nikolay, Birgit; Truscott, James E; Hollingsworth, T Déirdre; Balabanova, Dina; Griffiths, Ulla K; Freeman, Matthew C; Allen, Elizabeth; Pullan, Rachel L; Anderson, Roy M

    2015-10-19

    In recent years, an unprecedented emphasis has been given to the control of neglected tropical diseases, including soil-transmitted helminths (STHs). The mainstay of STH control is school-based deworming (SBD), but mathematical modelling has shown that in all but very low transmission settings, SBD is unlikely to interrupt transmission, and that new treatment strategies are required. This study seeks to answer the question: is it possible to interrupt the transmission of STH, and, if so, what is the most cost-effective treatment strategy and delivery system to achieve this goal? Two cluster randomised trials are being implemented in contrasting settings in Kenya. The interventions are annual mass anthelmintic treatment delivered to preschool- and school-aged children, as part of a national SBD programme, or to entire communities, delivered by community health workers. Allocation to study group is by cluster, using predefined units used in public health provision-termed community units (CUs). CUs are randomised to one of three groups: receiving either (1) annual SBD; (2) annual community-based deworming (CBD); or (3) biannual CBD. The primary outcome measure is the prevalence of hookworm infection, assessed by four cross-sectional surveys. Secondary outcomes are prevalence of Ascaris lumbricoides and Trichuris trichiura, intensity of species infections and treatment coverage. Costs and cost-effectiveness will be evaluated. Among a random subsample of participants, worm burden and proportion of unfertilised eggs will be assessed longitudinally. A nested process evaluation, using semistructured interviews, focus group discussions and a stakeholder analysis, will investigate the community acceptability, feasibility and scale-up of each delivery system. Study protocols have been reviewed and approved by the ethics committees of the Kenya Medical Research Institute and National Ethics Review Committee, and London School of Hygiene and Tropical Medicine. The study has a

  13. Which risk understandings can be derived from the current disharmonized regulation of complementary and alternative medicine in Europe?

    Science.gov (United States)

    Wiesener, Solveig; Salamonsen, Anita; Fønnebø, Vinjar

    2018-01-10

    Many European citizens are seeking complementary and alternative medicine (CAM). These treatments are regulated very differently in the EU/EFTA countries. This may demonstrate differences in how risk associated with the use of CAM is perceived. Since most CAM treatments are practiced fairly similarly across Europe, differing risk understandings may influence patient safety for European CAM users. The overall aim of this article is thus to contribute to an overview and awareness of possible differing risk understandings in the field of CAM at a policymaking/structural level in Europe. The study is a re-analysis of data collected in the CAMbrella EU FP7 document and interview study on the regulation of CAM in 39 European countries. The 12 CAM modalities included in the CAMbrella study were ranked with regard to assumed risk potential depending on the number of countries limiting its practice to regulated professions. The 39 countries were ranked according to how many of the included CAM modalities they limit to be practiced by regulated professions. Twelve of 39 countries generally understand the included CAM treatments to represent "high risk", 20 countries "low risk", while the remaining 7 countries understand CAM treatments as carrying "very little or no risk". The CAM modalities seen as carrying a risk high enough to warrant professional regulation in the highest number of countries are chiropractic, acupuncture, massage, homeopathy and osteopathy. The countries understanding most of the CAM modalities in the study as potentially high-risk treatments are with two exceptions (Portugal and Belgium) all concentrated in the southeastern region of Europe. The variation in regulation of CAM may represent a substantial lack of common risk understandings between health policymakers in Europe. We think the discrepancies in regulation are to a considerable degree also based on factors unrelated to patient risk. We argue that it is important for patient safety that policy

  14. Enhancing liquid-liquid and solid-liquid phase separation by integrating alternating current electrocoagulators with processing and wastewater control systems

    International Nuclear Information System (INIS)

    Ryan, P.E.; Stanczyk, T.F.

    1989-01-01

    Coal, pigments, pharmaceutical solids, ceramics, carbon, clays, metallic powders and ores are among the categorical groups of products which are wasted as suspended solids in aqueous-based wash solutions. Phase separation and recovery of these solids by conventional dewatering systems is costly and relatively inefficient. Alternating current can be used to neutralize the electrical charge on fine and ultra-fine particles in aqueous suspensions, and facilitate agglomeration and settling of these particulates without using chemicals while improving recovery efficiencies. This paper provides an overview of the technology and discusses applications and benefits in the areas of in-plant processing, industrial wastewater treatment, site remediation and water purification

  15. Potential geographic "hotspots" for drug-injection related transmission of HIV and HCV and for initiation into injecting drug use in New York City, 2011-2015, with implications for the current opioid epidemic in the US.

    Science.gov (United States)

    Des Jarlais, D C; Cooper, H L F; Arasteh, K; Feelemyer, J; McKnight, C; Ross, Z

    2018-01-01

    We identified potential geographic "hotspots" for drug-injecting transmission of HIV and hepatitis C virus (HCV) among persons who inject drugs (PWID) in New York City. The HIV epidemic among PWID is currently in an "end of the epidemic" stage, while HCV is in a continuing, high prevalence (> 50%) stage. We recruited 910 PWID entering Mount Sinai Beth Israel substance use treatment programs from 2011-2015. Structured interviews and HIV/ HCV testing were conducted. Residential ZIP codes were used as geographic units of analysis. Potential "hotspots" for HIV and HCV transmission were defined as 1) having relatively large numbers of PWID 2) having 2 or more HIV (or HCV) seropositive PWID reporting transmission risk-passing on used syringes to others, and 3) having 2 or more HIV (or HCV) seronegative PWID reporting acquisition risk-injecting with previously used needles/syringes. Hotspots for injecting drug use initiation were defined as ZIP codes with 5 or more persons who began injecting within the previous 6 years. Among PWID, 96% injected heroin, 81% male, 34% White, 15% African-American, 47% Latinx, mean age 40 (SD = 10), 7% HIV seropositive, 62% HCV seropositive. Participants resided in 234 ZIP codes. No ZIP codes were identified as potential hotspots due to small numbers of HIV seropositive PWID reporting transmission risk. Four ZIP codes were identified as potential hotspots for HCV transmission. 12 ZIP codes identified as hotspots for injecting drug use initiation. For HIV, the lack of potential hotspots is further validation of widespread effectiveness of efforts to reduce injecting-related HIV transmission. Injecting-related HIV transmission is likely to be a rare, random event. HCV prevention efforts should include focus on potential hotspots for transmission and on hotspots for initiation into injecting drug use. We consider application of methods for the current opioid epidemic in the US.

  16. Pellicle transmission uniformity requirements

    Science.gov (United States)

    Brown, Thomas L.; Ito, Kunihiro

    1998-12-01

    Controlling critical dimensions of devices is a constant battle for the photolithography engineer. Current DUV lithographic process exposure latitude is typically 12 to 15% of the total dose. A third of this exposure latitude budget may be used up by a variable related to masking that has not previously received much attention. The emphasis on pellicle transmission has been focused on increasing the average transmission. Much less, attention has been paid to transmission uniformity. This paper explores the total demand on the photospeed latitude budget, the causes of pellicle transmission nonuniformity and examines reasonable expectations for pellicle performance. Modeling is used to examine how the two primary errors in pellicle manufacturing contribute to nonuniformity in transmission. World-class pellicle transmission uniformity standards are discussed and a comparison made between specifications of other components in the photolithographic process. Specifications for other materials or parameters are used as benchmarks to develop a proposed industry standard for pellicle transmission uniformity.

  17. Cost estimation of HVDC transmission system of Bangka's NPP candidates

    Science.gov (United States)

    Liun, Edwaren; Suparman

    2014-09-01

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different.

  18. Offshore Transmission Technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-10-15

    The purpose of this document is to give an overview of offshore electricity transmission technologies. In particular this document is concerned with the use of High Voltage Direct Current (HVDC) systems and more specifically with the development of Voltage Source Converter (VSC) technology. This report outlines the current state of the main technology groups required for offshore HVDC transmission as well as giving examples of offshore projects (both current and future). Finally some indications of likely unit costs for HV assets are given.

  19. High voltage transmission lines - what are the hazards

    International Nuclear Information System (INIS)

    Repacholi, M.H.

    1985-01-01

    With the increasing use of high voltage alternating current (HVAC) transmission lines there is a growing concern among the public about possible human health effects resulting from exposure to the electric fields associated with these lines. While there is no definitive evidence of such effects, mounting public fear and activism over hypothesized health risks is already causing delays in the licensing and constuction of major power transmission facilities, and is encouraging the formation of regulatory policy. This paper briefly reviews the concerns, biological effects data and standards for HVAC transmission lines

  20. Evidence for extended age dependent maternal immunity in infected children: mother to child transmission of HIV infection and potential interventions including sulfatides of the human fetal adnexa and complementary or alternative medicines.

    Science.gov (United States)

    Bhargav, Hemant; Huilgol, Vidya; Metri, Kashinath; Sundell, I Birgitta; Tripathi, Satyam; Ramagouda, Nagaratna; Jadhav, Mahesh; Raghuram, Nagarathna; Ramarao, Nagendra Hongasandra; Koka, Prasad S

    2012-01-01

    The two neighboring southwestern states of India, Karnataka and Maharashtra, have high incidence of HIV/AIDS and are among the six most high prevalence HIV infected states. In Karnataka state, the northern districts of Bagalkot, Belgaum and Bijapur (the three Bs) and in Maharashtra state, the southern districts of Sangli, Satara, and Solapur (the three Ss) are the areas with the highest incidence of HIV/AIDS. We have evaluated the incidence of maternal to child transmission (MTCT) of HIV-1 infection in Belgaum District which is more than 500 kilometers distance by road from the campus in greater Bangalore (Karnataka State). We have obtained the prenatal CD4 counts of HIV infected pregnant mothers. We have also screened the HIV infected children in two orphanages (rehabilitation centres for HIV infected children) in Belgaum District. The clinical conditions of these infected children were assessed for their CD4 counts, anti-retroviral therapy (ART) intake status, outpatient illnesses and body composition. We have observed that there is an influence of the age factor on the CD4 counts of the HIV infected children. Further, in view of the role of our recently found involvement of sulfatide, 3-O- galactosylceramide, in inhibition of HIV-1 replication and enhancement of hematopoiesis which is otherwise inhibited due to such infection, we have discussed the possible role of sulfatides that biologically occur in the fetal adnexa (placentatrophoblasts /amnion/chorion-umbilical cord), in containing HIV infection as a potential safer alternative to the ART regimens currently approved to be clinically practiced. Lastly, we have discussed the complementary and alternative medicine (CAM) therapies such as evidence based yoga and ayurveda as add-on to ART in potential elimination of MTCT of HIV infection. Out of a total of 150 children delivered by HIV infected mothers, 13 children were found to be positive as determined by the dried blood smear (DBS) for virological testing

  1. Airspace: Antarctic Sound Transmission

    OpenAIRE

    Polli, Andrea

    2009-01-01

    This paper investigates how sound transmission can contribute to the public understanding of climate change within the context of the Poles. How have such transmission-based projects developed specifically in the Arctic and Antarctic, and how do these works create alternative pathways in order to help audiences better understand climate change? The author has created the media project Sonic Antarctica from a personal experience of the Antarctic. The work combines soundscape recordings and son...

  2. Electrically induced contraction levels of the quadriceps femoris muscles in healthy men: the effects of three patterns of burst-modulated alternating current and volitional muscle fatigue.

    Science.gov (United States)

    Parker, Michael G; Broughton, Alex J; Larsen, Ben R; Dinius, Josh W; Cimbura, Mac J; Davis, Matthew

    2011-12-01

    The purpose of this study was to compare electrically induced contraction levels produced by three patterns of alternating current in fatigued and nonfatigued skeletal muscles. Eighteen male volunteers without health conditions, with a mean (SD) age of 24.9 (3.4) yrs were randomly exposed to a fatiguing volitional isometric quadriceps contraction and one of three patterns of 2.5-KHz alternating current; two were modulated at 50 bursts per second (10% burst duty cycle with five cycles per burst and 90% burst duty cycle with 45 cycles per burst), and one pattern was modulated at 100 bursts per second (10% burst duty cycle with 2.5 cycles per burst). The electrically induced contraction levels produced by the three patterns of electrical stimulation were compared before and after the fatiguing contraction. The 10% burst duty cycles produced 42.9% (95% confidence interval, 29.1%-56.7%) and 32.1% (95% confidence interval, 18.2%-45.9%) more muscle force (P stronger muscle contractions. Furthermore, the stimulation patterns had no influence on the difference in muscle force before and after the fatiguing quadriceps contraction. Consequently, for clinical applications in which high forces are desired, the patterns using the 10% burst duty cycle may be helpful.

  3. Current levels and composition profiles of PBDEs and alternative flame retardants in surface sediments from the Pearl River Delta, southern China: Comparison with historical data

    International Nuclear Information System (INIS)

    Chen, She-Jun; Feng, An-Hong; He, Ming-Jing; Chen, Man-Ying; Luo, Xiao-Jun; Mai, Bi-Xian

    2013-01-01

    Polybrominated diphenyl ethers (PBDEs) and alternative flame retardants were measured in surface sediments collected during 2009–2010 from the Pearl River Delta, southern China (a large manufacturing base for electronics/electrical products), to evaluate the influence of China's RoHS directive (adopted in 2006) on their environmental occurrence. The concentrations in sediments from different water systems ranged from 3.67 to 2520 ng/g (average of 17.1–588 ng/g) for PBDEs and from 0.22 to 5270 ng/g (average of 11.3–454 ng/g) for the alternative retardants. Although the PBDE levels have decreased significantly compared with those in sediments collected in 2002 in this region, the levels of alternative decabromodiphenyl ethane (DBDPE) have exceeded those of BDE209 (two predominant halogenated flame retardants (HFRs) in China) in the majority of sediments. This finding suggests a different contaminant pattern of HFRs in current sediments due to the replacement of the deca-BDE mixture with DBDPE in this region. In addition, sediment concentrations of discontinued PBDEs in the rural area are clearly elevated due to e-waste dismantling. The congener profiles of PBDEs in the current sediments (with more abundant lower-brominated congeners) differed substantially from those in 2002 and from the technical products, suggesting that biological or photolytic debromination of PBDEs may have occurred in the environment. - Highlights: ► PBDE levels in sediments have decreased substantially since China's RoHS directive. ► Contamination of novel DBDPE has exceeded that of deca-BDE in the PRD sediments. ► The congener profiles of PBDEs in the sediments have changed significantly. ► Significant biological or photolytic degradation of PBDEs may occur in the environment

  4. Evidence of previous but not current transmission of chikungunya virus in southern and central Vietnam: Results from a systematic review and a seroprevalence study in four locations.

    Directory of Open Access Journals (Sweden)

    Tran Minh Quan

    2018-02-01

    Full Text Available Arbovirus infections are a serious concern in tropical countries due to their high levels of transmission and morbidity. With the outbreaks of chikungunya (CHIKV in surrounding regions in recent years and the fact that the environment in Vietnam is suitable for the vectors of CHIKV, the possibility of transmission of CHIKV in Vietnam is of great interest. However, information about CHIKV activity in Vietnam remains limited.In order to address this question, we performed a systematic review of CHIKV in Vietnam and a CHIKV seroprevalence survey. The seroprevalence survey tested for CHIKV IgG in population serum samples from individuals of all ages in 2015 from four locations in Vietnam.The four locations were An Giang province (n = 137, Ho Chi Minh City (n = 136, Dak Lak province (n = 137, and Hue City (n = 136. The findings give us evidence of some CHIKV activity: 73/546 of overall samples were seropositive (13.4%. The age-adjusted seroprevalences were 12.30% (6.58-18.02, 13.42% (7.16-19.68, 7.97% (3.56-12.38, and 3.72% (1.75-5.69 in An Giang province, Ho Chi Minh City, Dak Lak province, and Hue City respectively. However, the age-stratified seroprevalence suggests that the last transmission ended around 30 years ago, consistent with results from the systematic review. We see no evidence for on-going transmission in three of the locations, though with some evidence of recent exposure in Dak Lak, most likely due to transmission in neighbouring countries. Before the 1980s, when transmission was occurring, we estimate on average 2-4% of the population were infected each year in HCMC and An Giang and Hue (though transmision ended earlier in Hue. We estimate lower transmission in Dak Lak, with around 1% of the population infected each year.In conclusion, we find evidence of past CHIKV transmission in central and southern Vietnam, but no evidence of recent sustained transmission. When transmission of CHIKV did occur, it appeared to be widespread and

  5. Induced- and alternating-current electro-osmotic control of the diffusion layer growth in a microchannel-membrane interface device

    Science.gov (United States)

    Park, Sinwook; Yossifon, Gilad

    2014-11-01

    The passage of an electric current through an ionic permselective medium under an applied electric field is characterized by the formation of ionic concentration gradients, which result in regions of depleted and enriched ionic concentration at opposite ends of the medium. Induced-current electro-osmosis (ICEO) and alternating-current-electro-osmosis (ACEO) are shown to control the growth of the diffusion layer (DL) which, in turn, controls the diffusion limited ion transport through the microchannel-membrane system. We fabricated and tested devices made of a Nafion membrane connecting two opposite PDMS microchannels. An interdigitated electrode array was embedded within the microchannel with various distances from the microchannel-membrane interface. The induced ICEO (floating electrodes) / ACEO (active electrodes) vortices formed at the electrode array stir the fluid and thereby suppress the growth of the DL. The intensity of the ACEO vortices is controlled by either varying the voltage amplitude or the frequency, each having its own unique effect. Enhancement of the limiting current by on-demand control of the diffusion length is of importance in on-chip electro-dialysis, desalination and preconcentration of analytes.

  6. Signal sensitivity of alternating current potential drop measurement for crack detection of conductive substrate with tunable coating materials through finite element modeling

    International Nuclear Information System (INIS)

    Rao, Simha Sandeep; Zhao, Huijuan; Liu, Ming; Peng, Fei; Zhang, Bo

    2016-01-01

    We adopt a finite element numerical modeling approach to investigate the electromagnetic coupling effect of two parallel electric conductors with tunable electric conductivity σ and magnetic permeability μ . For two parallel conductors C and S ( μ C   ⋅  σ C   ≤  μ S   ⋅  σ S ), we find that the shape of current density profile of conductor S is dependent on the product of μ C   ⋅  σ C , while the magnitude is determined by the AC current frequency f . On the other hand, the frequency f affects not only the shape but also the magnitude of the current density profile of conductor C. We further adopt a coplanar model to investigate the signal sensitivity of alternating current potential drop (ACPD) measurement for both surface crack and inner crack detection. We find that with modified coating materials (lower electric conductivity and higher magnetic permeability, compared with the substrate material properties), the crack detection signal sensitivity can be greatly enhanced for both the cracks within the coating and at the coating/substrate interface, where cracks are most commonly encountered in real situations. (paper)

  7. Control strategy minimizing the converter-alternating current motor losses: application to electric traction; Strategies de commande minimisant les pertes d'un ensemble convertisseur - machine alternative: application a la traction electrique

    Energy Technology Data Exchange (ETDEWEB)

    Bastiani, Ph.

    2001-02-01

    Improving the efficiency of the converter-alternating current motor system is a major task in electric traction. Global energy optimisation implies a specific approach at system scale. To reach this goal, we have chosen an algebraic method using sub-system models. To start with, a synchronous machine Park model is developed to take account magnetic saturation and iron losses. Then, an averaged model of the voltage inverter is used in order to obtain a simplified model of the losses to be implemented in our optimisation method. This is how the global model is built including losses in the synchronous machine along with the losses of the power converter. Experimental results are there to validate our approach. This study proposes a method based on algebraic formulation of the general laws to control torque. Algorithms take into account magnetic circuits saturation and power losses in both the machine and its converter. Here again, experimental results validate the algorithm on several test benches. Achieved efficiency improvement is important compared to existing usual control strategies. The proposed method can be generalised to other machine-converter systems. As a matter of fact we have extended our study to the induction machine. As a complement ti this study we have looked at the effects natural limitations of voltages and currents in the torque-speed plane. Therefore algebraic formulation of the torque-speed plane and optimisation strategies are proposed including those constraints. (author)

  8. Neuroglial Transmission

    DEFF Research Database (Denmark)

    Gundersen, Vidar; Storm-Mathisen, Jon; Bergersen, Linda Hildegard

    2015-01-01

    as a signaling substance recently shown to act on specific lactate receptors in the brain. Complementing neurotransmission at a synapse, neuroglial transmission often implies diffusion of the transmitter over a longer distance and concurs with the concept of volume transmission. Transmission from glia modulates...... synaptic neurotransmission based on energetic and other local conditions in a volume of tissue surrounding the individual synapse. Neuroglial transmission appears to contribute significantly to brain functions such as memory, as well as to prevalent neuropathologies....

  9. The Role of Demand Resources In Regional Transmission Expansion Planning and Reliable Operations

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Brendan J [ORNL

    2006-07-01

    Investigating the role of demand resources in regional transmission planning has provided mixed results. On one hand there are only a few projects where demand response has been used as an explicit alternative to transmission enhancement. On the other hand there is a fair amount of demand response in the form of energy efficiency, peak reduction, emergency load shedding, and (recently) demand providing ancillary services. All of this demand response reduces the need for transmission enhancements. Demand response capability is typically (but not always) factored into transmission planning as a reduction in the load which must be served. In that sense demand response is utilized as an alternative to transmission expansion. Much more demand response is used (involuntarily) as load shedding under extreme conditions to prevent cascading blackouts. The amount of additional transmission and generation that would be required to provide the current level of reliability if load shedding were not available is difficult to imagine and would be impractical to build. In a very real sense demand response solutions are equitably treated in every region - when proposed, demand response projects are evaluated against existing reliability and economic criteria. The regional councils, RTOs, and ISOs identify needs. Others propose transmission, generation, or responsive load based solutions. Few demand response projects get included in transmission enhancement plans because few are proposed. But this is only part of the story. Several factors are responsible for the current very low use of demand response as a transmission enhancement alternative. First, while the generation, transmission, and load business sectors each deal with essentially the same amount of electric power, generation and transmission companies are explicitly in the electric power business but electricity is not the primary business focus of most loads. This changes the institutional focus of each sector. Second

  10. Electrical and Biological Effects of Transmission Lines: A Review.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jack M.

    1989-06-01

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

  11. Compositionally graded Fe{sub (1−x)}-Pt{sub (x)} nanowires produced by alternating current electrodeposition into alumina templates

    Energy Technology Data Exchange (ETDEWEB)

    Fardi-Ilkhchy, Ali [Faculty of Materials Engineering, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); Nasirpouri, Farzad, E-mail: Nasirpouri@sut.ac.ir [Faculty of Materials Engineering, Sahand University of Technology, Tabriz 51335-1996 (Iran, Islamic Republic of); Bran, Cristina; Vázquez, Manuel [Institute of Materials Science of Madrid, CSIC, 28049 Madrid (Spain)

    2016-12-15

    Fe{sub (1−x)}-Pt{sub (x)} (0alternating current (AC) electrodeposition into nanoporous aluminum oxide templates through a systematic approach. The effect of AC electrodeposition parameters such as frequency, voltage and electrolyte concentration on morphology and chemical composition of Fe-Pt alloy nanowires was studied. Based on experimental data, AC sine wave deposition at an intermediate voltage of 12 V{sub rms} and a frequency of 50 Hz, produces nanowires with nearly stoichiometric composition (Fe{sub 42}Pt{sub 58}) and a reasonably good uniformity of pore filling. However, there is a gradual change of composition in Fe-Pt alloy nanowires along the length under certain AC parameters. The observed dependency of alloy composition on the deposition voltage and frequency of AC electrodeposition is explained by an interplay between reduction potentials and diffusion coefficients of Fe and Pt ions which makes FePt system able to access compositionally graded nanowires. Magnetic measurements of nanowires of as-deposited nanowires confirm that maximum coercivity of 1.55 kOe is observed for nearly stoichiometric composition which increases up to 1.81 kOe after thermal annealing at 550 °C. - Graphical abstract: Evaluation of synthesizing extrinsic parameters (such as deposition voltages and frequency) and intrinsic parameters (diffusion coefficient and reduction potential of ion species) in compositionally graded Fe{sub (1−x)}-Pt{sub (x)} nanowires prepared by alternating current electrodeposition into alumina templates.

  12. Electricity transmission congestion costs: A review of recent reports

    Energy Technology Data Exchange (ETDEWEB)

    Lesieutre, Bernard C.; Eto, Joseph H.

    2003-10-01

    Recently, independent system operators (ISOs) and others have published reports on the costs of transmission congestion. The magnitude of congestion costs cited in these reports has contributed to the national discussion on the current state of U.S. electricity transmission system and whether it provides an adequate platform for competition in wholesale electricity markets. This report reviews reports of congestion costs and begins to assess their implications for the current national discussion on the importance of the U.S. electricity transmission system for enabling competitive wholesale electricity markets. As a guiding principle, we posit that a more robust electricity system could reduce congestion costs; and thereby, (1) facilitate more vibrant and fair competition in wholesale electricity markets, and (2) enable consumers to seek out the lowest prices for electricity. Yet, examining the details suggests that, sometimes, there will be trade-offs between these goals. Therefore, it is essential to understand who pays, how much, and how do they benefit in evaluating options (both transmission and non-transmission alternatives) to address transmission congestion. To describe the differences among published estimates of congestion costs, we develop and motivate three ways by which transmission congestion costs are calculated in restructured markets. The assessment demonstrates that published transmission congestion costs are not directly comparable because they have been developed to serve different purposes. More importantly, critical information needed to make them more comparable, for example in order to evaluate the impacts of options to relieve congestion, is sometimes not available.

  13. 78 FR 50405 - Amended Application for Presidential Permit; Northern Pass Transmission LLC

    Science.gov (United States)

    2013-08-19

    ... Pass proposes to construct and operate a primarily overhead high-voltage direct current (HVDC) electric transmission line that would originate at an HVDC converter station to be constructed at the Des Cantons Substation in Qu[eacute]bec, Canada, then would be converted from HVDC to alternating current (AC) in...

  14. Alternative formulations of the electricity tax

    International Nuclear Information System (INIS)

    2003-01-01

    According to EFTA's surveillance authority ESA, the current form of the electricity tax may have a competition distorting effect since only the industry and a few other sectors are exempt from it. This document discusses four alternative formulations of the electricity tax: same tax for all business sectors and households, defining a maximum payment for each firm, introduce a tax on power transmission, or have taxation only on power used for heating.

  15. A search for space energy alternatives

    Science.gov (United States)

    Gilbreath, W. P.; Billman, K. W.

    1978-01-01

    This paper takes a look at a number of schemes for converting radiant energy in space to useful energy for man. These schemes are possible alternatives to the currently most studied solar power satellite concept. Possible primary collection and conversion devices discussed include the space particle flux devices, solar windmills, photovoltaic devices, photochemical cells, photoemissive converters, heat engines, dielectric energy conversion, electrostatic generators, plasma solar collectors, and thermionic schemes. Transmission devices reviewed include lasers and masers.

  16. Ozone and dinitrogen monoxide production in atmospheric pressure air dielectric barrier discharge plasma effluent generated by nanosecond pulse superimposed alternating current voltage

    Science.gov (United States)

    Takashima, Keisuke; Kaneko, Toshiro

    2017-06-01

    The effects of nanosecond pulse superposition to alternating current voltage (NS + AC) on the generation of an air dielectric barrier discharge (DBD) plasma and reactive species are experimentally studied, along with measurements of ozone (O3) and dinitrogen monoxide (N2O) in the exhausted gas through the air DBD plasma (air plasma effluent). The charge-voltage cycle measurement indicates that the role of nanosecond pulse superposition is to induce electrical charge transport and excess charge accumulation on the dielectric surface following the nanosecond pulses. The densities of O3 and N2O in NS + AC DBD are found to be significantly increased in the plasma effluent, compared to the sum of those densities generated in NS DBD and AC DBD operated individually. The production of O3 and N2O is modulated significantly by the phase in which the nanosecond pulse is superimposed. The density increase and modulation effects by the nanosecond pulse are found to correspond with the electrical charge transport and the excess electrical charge accumulation induced by the nanosecond pulse. It is suggested that the electrical charge transport by the nanosecond pulse might result in the enhancement of the nanosecond pulse current, which may lead to more efficient molecular dissociation, and the excess electrical charge accumulation induced by the nanosecond pulse increases the discharge coupling power which would enhance molecular dissociation.

  17. Technique and Calculation Results of Currents and Voltages in the Circuits of the Measuring Element of the Protection Device of the Transmission Line Based on the Control of Transient Processes

    Science.gov (United States)

    Lachugin, V. F.; Kulikov, A. L.; Platonov, P. S.; Vucolov, V. Yu.

    2017-12-01

    The specifics of generation of the signals of current and voltage in the circuits of a directional element of wave relay protection during short circuit (SC) in overhead power transmission lines are considered. The computing method of transient processes in the protection circuits, including frequency filters, that attenuate the parameters of currents and voltages of the mode taking into account the higher harmonic components and probable deviations of the frequency of transmission line from the rated value is presented. It is revealed that it is advisable to implement the measuring circuits of the directional elements of wave relay protection with the three-section filter attenuating the frequencies from 45 to 55 Hz and the low pass filter with cutoff frequency that does not exceed 1 kHz.

  18. High-performance alternating current field-induced chromatic-stable white polymer electroluminescent devices employing a down-conversion layer

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yingdong; Chen, Yonghua; Smith, Gregory M. [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States); Sun, Hengda; Yang, Dezhi [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Nie, Wanyi; Li, Yuan; Huang, Wenxiao [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States); Ma, Dongge [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Carroll, David L., E-mail: carroldl@wfu.edu [Center for Nanotechnology and Molecular Materials, Department of Physics, Wake Forest University, Winston-Salem, NC 27105 (United States)

    2015-05-15

    In this work, a high-performance alternating current (AC) filed-induced chromatic-stable white polymer electroluminescence (WFIPEL) device was fabricated by combining a fluorophor Poly(9,9-dioctylfluorene) (PFO)-based blue device with a yellow down-conversion layer (YAG:Ce). A maximum luminance of this down-conversion FIPEL device achieves 3230 cd m{sup −2}, which is 1.41 times higher than the device without the down-conversion layer. A maximum current efficiency and power efficiency of the down-conversion WFIPEL device reach 19.7 cd A{sup −1} at 3050 cd m{sup −2} and 5.37 lm W{sup −1} at 2310 cd m{sup −2} respectively. To the best of our knowledge, the power efficiency is one of the highest reports for the WFIPEL up to now. Moreover, Commison Internationale de L’Eclairage (CIE) coordinates of (0.28, 0.30) is obtained by adjusting the thickness of the down-conversion layer to 30 μm and it is kept stable over the entire AC-driven voltage range. We believe that this AC-driven, down-conversion, WFIPEL device may offer an easy way towards future flat and flexible lighting sources. - Highlights: • A high-performance AC filed-induced chromatic-stable white polymer electroluminescence (WFIPEL) device was fabricated. • A maximum luminance, current efficiency, and power efficiency achieves 3230 cd m{sup −2}, 19.7 cd A{sup −1}, and 5.37 lm W{sup −1}, respectively. • The power efficiency is one of the highest reports for the WFIPEL up to now. • The EL spectrum kept very stable over the entire AC-driven voltage range.

  19. Transmission issues

    International Nuclear Information System (INIS)

    Bradford, J.; Wilson, L.; Thon, S.; Millar, N.

    2005-01-01

    This session on transmission issues focused on the role that transmission plays in electricity markets and the importance of getting the market structure right in terms of generation divestiture with buy back contracts, demand side responsive programs, transmission upgrades and long term contracts. The difficulties of distinguishing between market power and scarcity were examined along with some of the complications that ensue if transmission experiences congestion, as exemplified by the August 2003 blackout in eastern North America. The presentations described the best ways to handle transmission issues, and debated whether transmission should be deregulated or follow market forces. Issues of interconnections and reliability of connections were also debated along with the attempt to integrate renewables into the grid. Some presentations identified what new transmission must be built and what must be done to ensure that transmission gets built. The challenges and business opportunities for transmission in Alberta were discussed with reference to plans to invest in new infrastructure, where it is going outside of the province and how it works with other jurisdictions. Manitoba's Conawapa Hydro Project and its 2000 MW tie line to Ontario was also discussed. Some examples of non-optimal use of interconnections in Europe were also discussed in an effort to learn from these mistakes and avoid them in Canada. tabs., figs

  20. Transmission eigenvalues

    Science.gov (United States)

    Cakoni, Fioralba; Haddar, Houssem

    2013-10-01

    In inverse scattering theory, transmission eigenvalues can be seen as the extension of the notion of resonant frequencies for impenetrable objects to the case of penetrable dielectrics. The transmission eigenvalue problem is a relatively late arrival to the spectral theory of partial differential equations. Its first appearance was in 1986 in a paper by Kirsch who was investigating the denseness of far-field patterns for scattering solutions of the Helmholtz equation or, in more modern terminology, the injectivity of the far-field operator [1]. The paper of Kirsch was soon followed by a more systematic study by Colton and Monk in the context of developing the dual space method for solving the inverse scattering problem for acoustic waves in an inhomogeneous medium [2]. In this paper they showed that for a spherically stratified media transmission eigenvalues existed and formed a discrete set. Numerical examples were also given showing that in principle transmission eigenvalues could be determined from the far-field data. This first period of interest in transmission eigenvalues was concluded with papers by Colton et al in 1989 [3] and Rynne and Sleeman in 1991 [4] showing that for an inhomogeneous medium (not necessarily spherically stratified) transmission eigenvalues, if they existed, formed a discrete set. For the next seventeen years transmission eigenvalues were ignored. This was mainly due to the fact that, with the introduction of various sampling methods to determine the shape of an inhomogeneous medium from far-field data, transmission eigenvalues were something to be avoided and hence the fact that transmission eigenvalues formed at most a discrete set was deemed to be sufficient. In addition, questions related to the existence of transmission eigenvalues or the structure of associated eigenvectors were recognized as being particularly difficult due to the nonlinearity of the eigenvalue problem and the special structure of the associated transmission

  1. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Murillo L., E-mail: murillolongo@gmail.com [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Instituto de Biociências, Universidade Estadual Paulista, CP 510, 18618–970 Botucatu SP (Brazil); Calabresi, Marcos F.; Quini, Caio; Matos, Juliana F.; Miranda, José R.A.; Saeki, Margarida J. [Instituto de Biociências, Universidade Estadual Paulista, CP 510, 18618–970 Botucatu SP (Brazil); Bordallo, Heloisa N. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)

    2015-03-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn–Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH = 3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system.

  2. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel

    International Nuclear Information System (INIS)

    Martins, Murillo L.; Calabresi, Marcos F.; Quini, Caio; Matos, Juliana F.; Miranda, José R.A.; Saeki, Margarida J.; Bordallo, Heloisa N.

    2015-01-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn–Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH = 3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system

  3. On the behavior of reduced graphene oxide based electrodes coated with dispersed platinum by alternate current methods in the electrochemical degradation of reactive dyes.

    Science.gov (United States)

    Del Río, A I; García, C; Molina, J; Fernández, J; Bonastre, J; Cases, F

    2017-09-01

    The electrochemical behavior of different carbon-based electrodes with and without nanoparticles of platinum electrochemically dispersed on their surface has been studied. Among others, reduced graphene oxide based electrodes was used to determine the best conditions for the decolorization/degradation of the reactive dye C.I. Reactive Orange 4 in sulfuric medium. Firstly, the electrochemical behavior was evaluated by cyclic voltammetry. Secondly, different electrolyses were performed using two cell configurations: cell with anodic and cathodic compartments separated (divided configuration) and without any separation (undivided configuration). The best results were obtained when reduced graphene oxide based anodes were used. The degree of decolorization was monitored by spectroscopic methods and high performance liquid chromatography. It was found that all of them followed pseudo-first order kinetics. When reduced graphene oxide-based electrodes coated with dispersed platinum by alternate current methods electrodes were used, the lowest energy consumption and the higher decolorization kinetics rate were obtained. Scanning Electronic Microscopy was used to observe the morphological surface differences. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel.

    Science.gov (United States)

    Martins, Murillo L; Calabresi, Marcos F; Quini, Caio; Matos, Juliana F; Miranda, José R A; Saeki, Margarida J; Bordallo, Heloisa N

    2015-03-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn-Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH=3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Treating waste waters in small agglomerations. The current situation, commitments and alternatives; Depuracion de las aguas residuales en pequenos nuclear. Situacion actual, compromisos y alternativas

    Energy Technology Data Exchange (ETDEWEB)

    Collado Lara, R. [Universidad de Cantabria. (Spain)

    2003-07-01

    In 1991, the European Economic Community issued a directive on urban waste water treatment: (91/27/EEC). This directive laid down that such treatment had to be in place ny the period 2000-2005, depending on the application of different requirements according to the size of the agglomeration and the discharge area. A large number of sewage plants are being built in Spain at the present time, especially in medium-size and large agglomeration (pop>10.000 inhabitants). However, in the smaller agglomeration, over 50% of the waste waters have still to be treated. In agglomerations of less than 10.000 inhabitants, which make up 95% of the municipalities in Spain, it is possible to apply a greater diversity of treatments not all of them conventional that comply with the directive in question. Natural systems and biofilm processes are low-cost solutions that are well adapted to the natural environment. However, conventional technologies are virtually essential in medium-size and large agglomerations, as the lack of space and the exacting demands render them irreplaceable (Collado, 2002). This article describes the distribution of the municipalities in Spain according to the number of inhabitants, the current state os sewage treatment,the commitments made by the European Economic Community and the viable alternatives. Some comments have been added regarding the running of such systems and the need for them to be managed by associations of local councils or regional bodies. (Author)

  6. Influence of Al{sub 2}O{sub 3} reflective layer under phosphor layer on luminance and luminous efficiency characteristics in alternating-current plasma display panel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Choon-Sang [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Tae, Heung-Sik, E-mail: hstae@ee.knu.ac.kr [School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu (Korea, Republic of); Jung, Eun Young [Core Technology Lab., Corporate R and D Center, Samsung SDI Company Ltd., Cheonan (Korea, Republic of)

    2013-11-29

    This paper examines the optical and discharge characteristics of alternating-current plasma display panel when adopting the Al{sub 2}O{sub 3} reflective layer. The Al{sub 2}O{sub 3} reflective layer is deposited under the phosphor layer by using the screen-printing method. The resulting changes in the optical and discharge characteristics, including the power consumption, color temperature, luminance, luminous efficiency, scanning electron microscopy image, and reflectance, are then compared for both cases with and without Al{sub 2}O{sub 3} reflective layer. As a result of optimizing the thicknesses between the Al{sub 2}O{sub 3} and phosphor layers, the luminance and luminous efficiency are improved by about 17% and 7%, respectively. - Highlights: • We examine characteristics of plasma display panel when adopting reflective layer. • Al{sub 2}O{sub 3} reflective layer was deposited under the phosphor layer. • Al{sub 2}O{sub 3} reflective layer with flaky shape is very effective in enhancing luminance.

  7. A FRAME response to the Draft Report on Alternative (Non-animal) Methods for Cosmetics Testing: Current Status and Future Prospects--2010.

    Science.gov (United States)

    Balls, Michael; Clothier, Richard

    2010-10-01

    This response on behalf of FRAME to the European Commission's consultation on the five chapters of the Draft Report on Alternative (Non-animal) Methods for Cosmetics Testing: Current Status and Future Prospects--2010, is via a Comment in ATLA, rather than via the template supplied by the Commission. This is principally so that a number of general points about cosmetic ingredient testing can be made. It is concluded that the five draft chapters do not provide a credible basis for the Commission's forthcoming report to the European Parliament and the European Council on the five cosmetic ingredient safety issues for which the 7th Amendment to the Cosmetic Directive's ban on animal testing was postponed until 2013. This is mainly because there is insufficient focus in the draft chapters on the specific nature of cosmetic ingredients, their uses, their local effects and metabolism at their sites of application, and, in particular, on whether their possible absorption into the body would be likely to lead to their accumulation in target sites at levels approaching Thresholds of Toxicological Concern. Meanwhile, there continues to be uncertainty about how the provisions of the Cosmetics Directive should be applied, given the requirements of the REACH system and directives concerned with the safety of other chemicals and products. © 2010 FRAME.

  8. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  9. Low-current solutions for wireless point-to-point sensor data transmission for long-term applications; Stromsparende Loesungen fuer drahtlose Punkt-zu-Punkt-Sensordatenuebertragung fuer langjaehrigen Betrieb

    Energy Technology Data Exchange (ETDEWEB)

    Milosiu, H. [Fraunhofer-Institut fuer Integrierte Schaltungen IIS, Erlangen (Germany)

    2008-07-01

    Choosing wireless standard such as Bluetooth or Zigbee, the customer can find numerous low-cost chip sets. In particular applications proprietary solutions are superior to wireless standard solutions, especially for transmission of small data amounts from point to point. The complex transmission protocol of a wireless standard forms a inflexible precondition for the user and may exclude the choice of a wireless standard. In addition, a relatively high energy consumption disables battery-operated low-maintenance applications. Fraunhofer Institute for Integrated Circuits IIS in Erlangen now offers a solution to that problem. This article would like to show the benefits of low-current proprietary wireless systems. An implementation of a lowcurrent wireless system using BiCMOS technology for wireless sensor networks is presented. (orig.)

  10. Data transmission

    National Research Council Canada - National Science Library

    Tugal, Dogan A; Tugal, Osman

    1989-01-01

    This updated second edition provides working answers to today's critical questions about designing and managing all types of data transmission systems and features a new chapter on local area networks (LANs...

  11. Beta band transcranial alternating (tACS and direct current stimulation (tDCS applied after initial learning facilitate retrieval of a motor sequence

    Directory of Open Access Journals (Sweden)

    Vanessa eKrause

    2016-01-01

    Full Text Available The primary motor cortex (M1 contributes to the acquisition and early consolidation of a motor sequence. Although the relevance of M1 excitability for motor learning has been supported, the significance of M1 oscillations remains an open issue. This study aims at investigating to what extent retrieval of a newly learned motor sequence can be differentially affected by motor-cortical transcranial alternating (tACS and direct current stimulation (tDCS. Alpha (10 Hz, beta (20 Hz or sham tACS was applied in 36 right-handers. Anodal or cathodal tDCS was applied in 30 right-handers. Participants learned an eight-digit serial reaction time task (SRTT; sequential vs. random with the right hand. Stimulation was applied to the left M1 after SRTT acquisition at rest for ten minutes. Reaction times were analyzed at baseline, end of acquisition, retrieval immediately after stimulation and reacquisition after eight further sequence repetitions.Reaction times during retrieval were significantly faster following 20 Hz tACS as compared to 10 Hz and sham tACS indicating a facilitation of early consolidation. TDCS yielded faster reaction times, too, independent of polarity. No significant differences between 20 Hz tACS and tDCS effects on retrieval were found suggesting that 20 Hz effects might be associated with altered motor-cortical excitability. Based on the behavioural modulation yielded by tACS and tDCS one might speculate that altered motor-cortical beta oscillations support early motor consolidation possibly associated with neuroplastic reorganization.

  12. Transcranial alternating current stimulation at beta frequency: lack of immediate effects on excitation and interhemispheric inhibition of the human motor cortex

    Directory of Open Access Journals (Sweden)

    Viola Rjosk

    2016-11-01

    Full Text Available Transcranial alternating current stimulation (tACS is a form of noninvasive brain stimulation and is capable of influencing brain oscillations and cortical networks. In humans, the endogenous oscillation frequency in sensorimotor areas peaks at 20 Hz. This beta-band typically occurs during maintenance of tonic motor output and seems to play a role in interhemispheric coordination of movements. Previous studies showed that tACS applied in specific frequency bands over primary motor cortex (M1 or the visual cortex modulates cortical excitability within the stimulated hemisphere. However, the particular impact remains controversial because effects of tACS were shown to be frequency, duration and location specific. Furthermore, the potential of tACS to modulate cortical interhemispheric processing, like interhemispheric inhibition (IHI, remains elusive. Transcranial magnetic stimulation (TMS is a noninvasive and well-tolerated method of directly activating neurons in superficial areas of the human brain and thereby a useful tool for evaluating the functional state of motor pathways. The aim of the present study was to elucidate the immediate effect of 10 min tACS in the β-frequency band (20 Hz over left M1 on IHI between M1s in 19 young, healthy, right-handed participants. A series of TMS measurements (MEP size, RMT, IHI from left to right M1 and vice versa was performed before and immediately after tACS or sham using a double-blinded, cross-over design. We did not find any significant tACS-induced modulations of intracortical excitation (as assessed by MEP size and RMT and/or interhemispheric inhibition (IHI. These results indicate that 10 min of 20 Hz tACS over left M1 seems incapable of modulating immediate brain activity or inhibition. Further studies are needed to elucidate potential aftereffects of 20 Hz tACS as well as frequency-specific effects of tACS on intracortical excitation and interhemispheric inhibition.

  13. Alternatives to allogeneic platelet transfusion.

    Science.gov (United States)

    Desborough, Michael J R; Smethurst, Peter A; Estcourt, Lise J; Stanworth, Simon J

    2016-11-01

    Allogeneic platelet transfusions are widely used for the prevention and treatment of bleeding in thrombocytopenia. Recent evidence suggests platelet transfusions have limited efficacy and are associated with uncertain immunomodulatory risks and concerns about viral or bacterial transmission. Alternatives to transfusion are a well-recognised tenet of Patient Blood Management, but there has been less focus on different strategies to reduce bleeding risk by comparison to platelet transfusion. Direct alternatives to platelet transfusion include agents to stimulate endogenous platelet production (thrombopoietin mimetics), optimising platelet adhesion to endothelium by treating anaemia or increasing von Willebrand factor levels (desmopressin), increasing formation of cross-linked fibrinogen (activated recombinant factor VII, fibrinogen concentrate or recombinant factor XIII), decreasing fibrinolysis (tranexamic acid or epsilon aminocaproic acid) or using artificial or modified platelets (cryopreserved platelets, lyophilised platelets, haemostatic particles, liposomes, engineered nanoparticles or infusible platelet membranes). The evidence base to support the use of these alternatives is variable, but an area of active research. Much of the current randomised controlled trial focus is on evaluation of the use of thrombopoietin mimetics and anti-fibrinolytics. It is also recognised that one alternative strategy to platelet transfusion is choosing not to transfuse at all. © 2016 John Wiley & Sons Ltd.

  14. Transmission rights and market power

    International Nuclear Information System (INIS)

    Bushnell, J.

    1999-01-01

    Most of the concerns about physical transmission rights relate to the ability to implicitly or explicitly remove that transmission capacity from the market-place. Under a very strict form of physical right, owners could simply choose not to sell it if they don't want to use it. Modifications that require the release of spare capacity back into an open market could potentially alleviate this problem but there is concern that such releases would not occur far enough in advance to be of much use to schedulers. Similarly, the transmission capacity that is made available for use by non-rights holders can also be manipulated by the owners of transmission rights. The alternative form, financial transmission rights, provide to their owners congestion payments, but physical control of transmission paths. In electricity markets such as California's, even financial transmission rights could potentially be utilized to effectively withhold transmission capacity from the marketplace. However, methods for withholding transmission capacity are somewhat more convoluted, and probably more difficult, for owners of financial rights than for owners of physical rights. In this article, the author discusses some of the potential concerns over transmission rights and their use for the exercise of various forms of market power

  15. Environmental concerns regarding electric power transmission in North America

    International Nuclear Information System (INIS)

    DeCicco, J.M.; Bernow, S.S.; Beyea, J.

    1992-01-01

    The electric utilities of North America have become ever more interconnected via transmission facilities, largely to insure reliability. Current policy discussions regarding transmission include calls for improved access, increased capacity, and deregulation to facilitate trade in electric power. From an environmental perspective, two issues have been notably absent in much of the debate: (1) a recognition of the full range of environmental impacts related to electricity transmission; and (2) the potential for end-use efficiency to address the reliability and economy requirements that motivate attention to transmission. This paper broaches these issues, starting with an elaboration of the environmental impacts, which range from global and regional effects to local concerns, including the potential health risks associated with electric and magnetic fields. We emphasize that transmission planning should occur as part of an integrated planning process, in which the environmental and social costs of various options are fully considered. We discuss the potential for end-use efficiency to lessen environmental impacts of both transmission and generation. We conclude that there is a need to ensure that environmental externalities and demand-side alternatives are adequately considered when transmission network expansions are proposed. (Author)

  16. Maternal health service disparities across incomes and implications on prevention of mother-to-child transmission service coverage: current context in Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Nibretie Gobezie Workneh

    2016-12-01

    Full Text Available About 69% of people living with HIV globally and over 90% of the children who acquired HIV infection are in Sub-Saharan Africa. Despite this, promising results have been observed, especially over the last decade – for example, a 25% decline in new HIV infections as compared to 2001 and a 38% decline in the number of children newly infected by HIV in 2012 as compared to 2009. However, the Global Plan and the Global Fast-Track Commitments of eliminating new HIV infections among children require addressing impediments to service expansion. In this regard, this paper attempts to draw attention to the extent to which disparities across income in using antenatal care (ANC services may constrain the prevention of mother-to-child transmission (PMTCT service expansion in Sub-Saharan Africa. The analysis is based on ANC service coverage data from Demographic and Health Surveys conducted between 2008 and 2015 in 31 Sub-Saharan African countries; and PMTCT coverage data from UNAIDS datasets released in 2016. Our analysis found that women in the highest wealth quintile are about three times more likely to frequently use ANC services (at least four visits as compared to those in the lowest wealth quintile (95%CI: 1.7-5.7, P<0.0001. A regression analysis shows that one-quarter of the PMTCT service coverage can be explained by the disparity in ANC use associated with income; and the higher the disparity in ANC use, the lower the PMTCT service (P<0.05. The findings suggest that achieving the ambitious plan of zero new HIV infections among children while keeping their mothers alive will require on-going PMTCT/ANC service integration and ensuring that programs reach women who are most in need; specifically those in the poorest income categories.

  17. The behavior of dissolution/passivation and the transformation of passive films during electrocoagulation: Influences of initial pH, Cr(VI) concentration, and alternating pulsed current

    International Nuclear Information System (INIS)

    Yang, Zhao-hui; Xu, Hai-yin; Zeng, Guang-ming; Luo, Yuan-ling; Yang, Xia; Huang, Jing; Wang, Li-ke; Song, Pei-pei

    2015-01-01

    Highlights: • Initial pH, Cr(VI) and APC could affect the behavior of dissolution/passivation in Fe-EC. • A dissolution/passivation region was constructed with different initial pH-Cr(VI). • The film was rich in Fe and Cr at high Cr(VI), whereas with lots of Fe but negligible of Cr at low Cr(VI). • The film was non-protective at long T APC , but became more stable and protective at short T APC . • Behavior of dissolution/passivation and passive film transformation in Fe-EC was elucidated. - Abstract: The passivation behavior of an iron anode for electrocoagulation (EC) was first investigated using response surface methodology (RSM). Tested initial pH range, Cr(VI) concentration and alternating pulsed current (APC) were 4.0 to 8.0, 52 to 520 mg L −1 and 10 to 590 s, respectively. The distance between electrodes was 25 mm, and K 2 SO 4 (1 g L −1 ) was used as the supporting electrolyte in a 2.5 L EC reactor. Results confirmed that initial pH, Cr(VI) concentration, and APC significantly influence the extent of passivation. Then, based on the interaction effect on passivation behavior between initial pH and Cr(VI) in RSM, a pH-Cr(VI)-dissolution/passivation diagram was constructed with galvanostatic measurements. The diagram showed an optimal dissolution region for EC operation. This optimum was characterized by a reasonable final pH for extended precipitation and little passivation. Results of the cyclic voltammetry and X-ray photoelectron spectroscopy revealed a significant difference in the composition and stability of oxide films in the region with more pronounced passivation. Interestingly, the APC had both positive and negative effect on the passivation behavior. Long period of APC (T APC = 590 s) produced a non-protective film, which favored the Fe 0 dissolution. However, a more stable and protective passive film with a uniform structure of Fe and Cr oxides was formed by short T APC (10 s). Based on the above results, this study elucidated the

  18. Brain Oscillatory and Hemodynamic Activity in a Bimanual Coordination Task Following Transcranial Alternating Current Stimulation (tACS): A Combined EEG-fNIRS Study.

    Science.gov (United States)

    Berger, Alisa; Pixa, Nils H; Steinberg, Fabian; Doppelmayr, Michael

    2018-01-01

    Motor control is associated with synchronized oscillatory activity at alpha (8-12 Hz) and beta (12-30 Hz) frequencies in a cerebello-thalamo-cortical network. Previous studies demonstrated that transcranial alternating current stimulation (tACS) is capable of entraining ongoing oscillatory activity while also modulating motor control. However, the modulatory effects of tACS on both motor control and its underlying electro- and neurophysiological mechanisms remain ambiguous. Thus, the purpose of this study was to contribute to gathering neurophysiological knowledge regarding tACS effects by investigating the after-effects of 10 Hz tACS and 20 Hz tACS at parietal brain areas on bimanual coordination and its concurrent oscillatory and hemodynamic activity. Twenty-four right-handed healthy volunteers (12 females) aged between 18 and 30 ( M = 22.35 ± 3.62) participated in the study and performed a coordination task requiring bimanual movements. Concurrent to bimanual motor training, participants received either 10 Hz tACS, 20 Hz tACS or a sham stimulation over the parietal cortex (at P3/P4 electrode positions) for 20 min via small gel electrodes (3,14 cm 2 Ag/AgCl, amperage = 1 mA). Before and three time-points after tACS (immediately, 30 min and 1 day), bimanual coordination performance was assessed. Oscillatory activities were measured by electroencephalography (EEG) and hemodynamic changes were examined using functional near-infrared spectroscopy (fNIRS). Improvements of bimanual coordination performance were not differently between groups, thus, no tACS-specific effect on bimanual coordination performance emerged. However, physiological measures during the task revealed significant increases in parietal alpha activity immediately following 10 Hz tACS and 20 Hz tACS which were accompanied by significant decreases of Hboxy concentration in the right hemispheric motor cortex compared to the sham group. Based on the physiological responses, we conclude that t

  19. Brain Oscillatory and Hemodynamic Activity in a Bimanual Coordination Task Following Transcranial Alternating Current Stimulation (tACS: A Combined EEG-fNIRS Study

    Directory of Open Access Journals (Sweden)

    Alisa Berger

    2018-04-01

    Full Text Available Motor control is associated with synchronized oscillatory activity at alpha (8–12 Hz and beta (12–30 Hz frequencies in a cerebello-thalamo-cortical network. Previous studies demonstrated that transcranial alternating current stimulation (tACS is capable of entraining ongoing oscillatory activity while also modulating motor control. However, the modulatory effects of tACS on both motor control and its underlying electro- and neurophysiological mechanisms remain ambiguous. Thus, the purpose of this study was to contribute to gathering neurophysiological knowledge regarding tACS effects by investigating the after-effects of 10 Hz tACS and 20 Hz tACS at parietal brain areas on bimanual coordination and its concurrent oscillatory and hemodynamic activity. Twenty-four right-handed healthy volunteers (12 females aged between 18 and 30 (M = 22.35 ± 3.62 participated in the study and performed a coordination task requiring bimanual movements. Concurrent to bimanual motor training, participants received either 10 Hz tACS, 20 Hz tACS or a sham stimulation over the parietal cortex (at P3/P4 electrode positions for 20 min via small gel electrodes (3,14 cm2 Ag/AgCl, amperage = 1 mA. Before and three time-points after tACS (immediately, 30 min and 1 day, bimanual coordination performance was assessed. Oscillatory activities were measured by electroencephalography (EEG and hemodynamic changes were examined using functional near-infrared spectroscopy (fNIRS. Improvements of bimanual coordination performance were not differently between groups, thus, no tACS-specific effect on bimanual coordination performance emerged. However, physiological measures during the task revealed significant increases in parietal alpha activity immediately following 10 Hz tACS and 20 Hz tACS which were accompanied by significant decreases of Hboxy concentration in the right hemispheric motor cortex compared to the sham group. Based on the physiological responses, we conclude that

  20. Electrical transmission

    Energy Technology Data Exchange (ETDEWEB)

    Sayers, D P

    1960-05-01

    After briefly tracing the history of electricity transmission, trends in high voltage transmission and experiments being conducted on 650 kV are discussed. 5000 miles of the U.K. grid are operated at 132 kV and 1000 at 275 kV, ultimately to provide a super grid at 380 kV. Problems are insulation, radio interference and the cost of underground lines (16 times that of overhead lines). Also considered are the economics of the grid as a means of transporting energy and as a means of spreading the peak load over the power stations in the most efficient manner. Finally, the question of amenities is discussed.

  1. Cost estimation of HVDC transmission system of Bangka’s NPP candidates

    Energy Technology Data Exchange (ETDEWEB)

    Liun, Edwaren, E-mail: edwaren@batan.go.id; Suparman, E-mail: edwaren@batan.go.id [Centre for Nuclear Energy Development, National Nuclear Energy Agency of Indonesia (Indonesia)

    2014-09-30

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different.

  2. Cost estimation of HVDC transmission system of Bangka’s NPP candidates

    International Nuclear Information System (INIS)

    Liun, Edwaren; Suparman

    2014-01-01

    Regarding nuclear power plant development in Bangka Island, it can be estimated that produced power will be oversupply for the Bangka Island and needs to transmit to Sumatra or Java Island. The distance between the regions or islands causing considerable loss of power in transmission by alternating current, and a wide range of technical and economical issues. The objective of this paper addresses to economics analysis of direct current transmission system to overcome those technical problem. Direct current transmission has a stable characteristic, so that the power delivery from Bangka to Sumatra or Java in a large scale efficiently and reliably can be done. HVDC system costs depend on the power capacity applied to the system and length of the transmission line in addition to other variables that may be different

  3. Intergenerational Transmission of Volunteering

    NARCIS (Netherlands)

    Bekkers, René

    2007-01-01

    In this article, I investigate the strength of intergenerational transmission of volunteering for non-profit associations in The Netherlands. Data from the Family Survey of the Dutch Population 2000 reveal that there are significant relations between current volunteering and parental volunteering in

  4. Intergenerational transmission of volunteerism

    NARCIS (Netherlands)

    Bekkers, R.H.F.P.

    2007-01-01

    In this article, I investigate the strength of intergenerational transmission of volunteering for non-profit associations in The Netherlands. Data from the Family Survey of the Dutch Population 2000 reveal that there are significant relations between current volunteering and parental volunteering in

  5. Fiber transmission and generation of ultrawideband pulses by direct current modulation of semi-conductor lasers and chirp-to-intensity conversion

    DEFF Research Database (Denmark)

    Company Torres, Victor; Prince, Kamau; Tafur Monroy, Idelfonso

    2008-01-01

    Optical pulses generated by current modulation of semiconductor lasers are strongly frequency chirped. This effect has been considered pernicious for optical communications. We take advantage of this effect for the generation of ultrawideband microwave signals by using an optical filter to achieve...... chirp-to-intensity conversion. We also experimentally achieve propagation through a 20 km nonzero dispersion shifted fiber with no degradation of the signal at the receiver. Our method constitutes a prospective low-cost solution and offers integration capabilities with fiber...

  6. Transmission and compression of an intense relativistic electron beam produced by a converging annular diode with return current feedback through the cathode. Pt. 2. The experiments

    International Nuclear Information System (INIS)

    Kelly, J.G.; Schuch, R.L.

    1976-02-01

    The complete results of the experiments with the converging annular diode within return current fedback through the cathode (Triax) are reported herein. The diode was designed to focus a relativistic high-current electron beam to a small focus. It did confirm the Triaxial theory detailed in Part I, and it did achieve a factor of 10 areal compression with 50% efficiency (which was below expectations). There were two principal reasons for this shortfall. First, the rapid diode plasma motion of 10 cm/μsec that was discovered necessitated the use of larger A-K gaps than expected and led to thicker beam sheets than are needed for good focusing. Second, the intrinsic angular spread of the electrons, even from the best cathode surfaces, introduced excessive angular momentum into the beam so that only a minor portion of the electrons could reach the axis. However, the yield of useful information about diode physics in general and about the influence of prepulse, the role of diode plasmas, the motion of energetic beams within conducting boundaries, diode emission properties, and diode diagnostic techniques in particle has had a significant and useful impact on the electron beam program at Sandia

  7. Alternative security

    International Nuclear Information System (INIS)

    Weston, B.H.

    1990-01-01

    This book contains the following chapters: The Military and Alternative Security: New Missions for Stable Conventional Security; Technology and Alternative Security: A Cherished Myth Expires; Law and Alternative Security: Toward a Just World Peace; Politics and Alternative Security: Toward a More Democratic, Therefore More Peaceful, World; Economics and Alternative Security: Toward a Peacekeeping International Economy; Psychology and Alternative Security: Needs, Perceptions, and Misperceptions; Religion and Alternative Security: A Prophetic Vision; and Toward Post-Nuclear Global Security: An Overview

  8. AC Voltage Control of DC/DC Converters Based on Modular Multilevel Converters in Multi-Terminal High-Voltage Direct Current Transmission Systems

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-12-01

    Full Text Available The AC voltage control of a DC/DC converter based on the modular multilevel converter (MMC is considered under normal operation and during a local DC fault. By actively setting the AC voltage according to the two DC voltages of the DC/DC converter, the modulation index can be near unity, and the DC voltage is effectively utilized to output higher AC voltage. This significantly decreases submodule (SM capacitance and conduction losses of the DC/DC converter, yielding reduced capital cost, volume, and higher efficiency. Additionally, the AC voltage is limited in the controllable range of both the MMCs in the DC/DC converter; thus, over-modulation and uncontrolled currents are actively avoided. The AC voltage control of the DC/DC converter during local DC faults, i.e., standby operation, is also proposed, where only the MMC connected on the faulty cable is blocked, while the other MMC remains operational with zero AC voltage output. Thus, the capacitor voltages can be regulated at the rated value and the decrease of the SM capacitor voltages after the blocking of the DC/DC converter is avoided. Moreover, the fault can still be isolated as quickly as the conventional approach, where both MMCs are blocked and the DC/DC converter is not exposed to the risk of overcurrent. The proposed AC voltage control strategy is assessed in a three-terminal high-voltage direct current (HVDC system incorporating a DC/DC converter, and the simulation results confirm its feasibility.

  9. Alternative approaches for vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status

    Science.gov (United States)

    The need for alternative approaches to the use of vertebrate animals for hazard assessing chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate or...

  10. Model for the ready definition and approximate comparison of alternative high voltage transmission systems. Phases II and III. Application to electric systems within the contiguous United States. [800 and 1200 kV; 400, 600, and 800 kV dc

    Energy Technology Data Exchange (ETDEWEB)

    1979-08-01

    Research on power delivery alternatives is reported. The first phase of this work was to develop a model of overhead transmission systems in the range of 362 to 1200 kV ac, and +-400 to +-800 kV dc. Such systems included transmission from generation to load and inter-connection of two large integrated systems, with and without the existence of an underlying lower voltage network in either case. This phase has been completed. The second and third phases involved application of the model to electric systems within selected regions of the US, and the entire US, respectively, dealing with real situations and including projected expansion to year 1987. The potential benefits and costs of using higher than existing transmission voltages were to be evaluated on this basis. Additionally, the most advantageous new voltage was to be determined taking into account direct and indirect benefits and costs. The results of the second and third phases are presented.

  11. Transmissions in vehicles 2010

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    ) Electromechanically actuated double clutch and EV transmissions (S. Rietentiet); (36) Linear actuation as a future choice to reduce costs and improve transmission efficiency (J. Behrenroth); (37) Forward-looking solutions for transmissions in electric vehicles - Transmission concepts for electric vehicle/potentials from system and component perspective (M.J. Derse); (38) Rotor position sensor for hybrid drives and electric drives - New generation eddy current position sensor (R. Moeller); (39) Electric axle drive with torque-vectoring-functionality (B.-R. Hoehn); (40) Extreme shift times and high comfort with the DCT are not a contradiction. - The function development and application of the DCT in the Mercedes-BenzSLS AMG (M. Hart); (41) The next generation of GETRAG PowerShift {sup registered} transmissions for FWD applications (S. Bungart); (42) Modular dual clutch transmission as all-wheel drivevariant for a sports car in the tip performance class (M. Fischer); (43) Potential of sintered friction linings in synchronizers (O. Back); (44) Friction between sliding pads and sleeve - Effects on the shifting process (T. Skubacz); (45) New developments in cold forging of hollow gear parts - Extension of the geometrical design of cold formed gear construction parts (S. Rudolf); (46) Start-up device for passenger cars based on a hydrodynamic coupling (A. Menne); (47) State and parameter estimation for the determination of clutch characteristics for wet clutches (A. Tarasow); (48) Control engineering in system development - Additional benefit thanks to control engineering using the example of active vibration damping (G. Bauer).

  12. Wireless transmission of power

    International Nuclear Information System (INIS)

    Grotz, T.

    1991-01-01

    This paper reports that it has been proven by researchers that electrical energy can be propagated around the world between the surface of the Earth and the ionosphere at extremely low frequencies in what is known as the Schumann Cavity. Experiments to data have shown that electromagnetic waves with frequencies in the range of 8 Hz, the fundamental Schumann Resonance frequency, propagate with litter attenuation around the planet within the Schumann Cavity. It is the intent of this research to determine if the Schumann Cavity can be resonated, if the power that is delivered to the cavity propagated with very low losses, and if power can be extracted at other locations within the cavity. Experimental data collected and calculations made in recent years support the hypothesis that wireless power transmission is a viable and practical alternative to the present systems of power transmission

  13. Transmission dynamics of Fasciola hepatica in the Plateau Region of Mexico. Effect of weather and treatment of mammals under current farm management.

    Science.gov (United States)

    Cruz-Mendoza, Irene; Quiroz-Romero, Héctor; Correa, Dolores; Gómez-Espinoza, Guillermo

    2011-01-10

    The aim of the present work was to study the dynamics of Fasciola hepatica natural infection in ovines, caprines, bovines and two mollusc species, Lymnaea (Fossaria) humilis and Lymnaea (F.) bulimoides, from 2004 to mid 2007 under normal farm management conditions, and the relation to climate changes. The study was performed in a research centre in the plateau of Mexico. Temperature and rainfall were registered every month, as well as the number and intensity of infection in livestock and molluscs, as determined by coprology and direct observation/cercariae release, respectively. The first two years mammals were treated with clorsulon/ivermectin because the animals were harbouring concomitant intestinal nematode infections and this was the available drug combination. During the second period treatment was with triclabendazole. The temperature ranged from around cero to 30 °C, except during September 2005 to January 2006, when a cold climate prevailed. The rainfall augmented every year in July-August, and slightly in April, 2006. Lymneid snails appeared during or immediately after the rainfall peaks of 2004 and 2006, while few L. humilis and no L. bulimoides were present during the same period of 2005, probably because it was cold. A total of 15564 cercariae were released from molluscs during the wet time of 2004, 76 during 2005 and 368 in 2006. Several peaks of infection in mammals were observed, most occurring up to 4 months after the snails had disappeared. As expected, the weather had strong impact on snails and then on livestock infection. Also, treatment given to livestock was related to reduced cercarieae release five months later. Therefore, the combination of treatment and inspection of snails in the biotopes where the livestock graze may facilitate control of fasciolosis under current farm management. Copyright © 2010 Elsevier B.V. All rights reserved.

  14. Alternative approaches to vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status

    Science.gov (United States)

    Lillicrap, Adam; Belanger, Scott; Burden, Natalie; Du Pasquier, David; Embry, Michelle; Halder, Marlies; Lampi, Mark; Lee, Lucy; Norberg-King, Teresa J.; Rattner, Barnett A.; Schirmer, Kristin; Thomas, Paul

    2016-01-01

    The need for alternative approaches to the use of vertebrate animals for hazard assessment of chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimized wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments has been banned; in other situations, the number of organisms tested has been dramatically reduced or the severity of the procedure refined. However, there is still a long way to go to achieve a complete replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is based not just on ethical considerations but also on reducing the cost of performing vertebrate ecotoxicity tests and in some cases on providing better information aimed at improving environmental risk assessments. The present Focus article provides an overview of the considerable advances that have been made toward alternative approaches for ecotoxicity assessments over the last few decades.

  15. Alternative approaches to vertebrate ecotoxicity tests in the 21st century: A review of developments over the last 2 decades and current status.

    Science.gov (United States)

    Lillicrap, Adam; Belanger, Scott; Burden, Natalie; Pasquier, David Du; Embry, Michelle R; Halder, Marlies; Lampi, Mark A; Lee, Lucy; Norberg-King, Teresa; Rattner, Barnett A; Schirmer, Kristin; Thomas, Paul

    2016-11-01

    The need for alternative approaches to the use of vertebrate animals for hazard assessment of chemicals and pollutants has become of increasing importance. It is now the first consideration when initiating a vertebrate ecotoxicity test, to ensure that unnecessary use of vertebrate organisms is minimized wherever possible. For some regulatory purposes, the use of vertebrate organisms for environmental risk assessments has been banned; in other situations, the number of organisms tested has been dramatically reduced or the severity of the procedure refined. However, there is still a long way to go to achieve a complete replacement of vertebrate organisms to generate environmental hazard data. The development of animal alternatives is based not just on ethical considerations but also on reducing the cost of performing vertebrate ecotoxicity tests and in some cases on providing better information aimed at improving environmental risk assessments. The present Focus article provides an overview of the considerable advances that have been made toward alternative approaches for ecotoxicity assessments over the last few decades. Environ Toxicol Chem 2016;35:2637-2646. © 2016 SETAC. © 2016 SETAC.

  16. Alternative energy and environmental concerns

    International Nuclear Information System (INIS)

    2002-01-01

    The New Brunswick Market Design Committee will address environmental concerns within the context of the new energy policy and market rules for the newly restructured electric power industry. The new rules that come with power restructuring will in some ways facilitate environmental protection but they can also complicate it. With open access markets, it will be possible to coordinate evolving energy frameworks with current environmental objectives. Restructuring provides an opportunity to create incentives and guidelines to operate in an environmentally sustainable manner, as suggested in the New Brunswick Energy Policy, White Paper which outlines green pricing, the development of a provincial Climate Change Action Plan, and promotion of alternative energy. The Market Design Committee examined the environmental concerns listed within the White Paper that pertain to the generation and transmission of electricity. These include the integration of energy and environmental policy. Other issues addressed in this report were trans-boundary and global air emissions, the development of a provincial climate change action plan, and a federal-provincial climate change framework agreement. New Brunswick will encourage the development of pilot studies that demonstrate the benefits of renewable and alternative technologies and that help promote the market to manufacture, sell and maintain renewable and alternative technologies in small-scale on-site power generation. This report also discussed the 4 key air pollutants for which specific treatment has been defined, including sulphur dioxide, nitrogen oxides, mercury and carbon dioxide. Recommendations for reducing these emissions include the use of renewable energy sources, the use of lower carbon fuels, increased efficiency of power transmission/generation/distribution systems, reducing power demand by the industrial sector, and promoting energy efficient building codes. 34 refs., 1 tab

  17. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  18. Wireless data transmission for high energy physics applications

    Science.gov (United States)

    Dittmeier, Sebastian; Brenner, Richard; Dancila, Dragos; Dehos, Cedric; De Lurgio, Patrick; Djurcic, Zelimir; Drake, Gary; Gonzalez Gimenez, Jose Luis; Gustafsson, Leif; Kim, Do-Won; Locci, Elizabeth; Pfeiffer, Ullrich; Röhrich, Dieter; Rydberg, Anders; Schöning, André; Siligaris, Alexandre; Soltveit, Hans Kristian; Ullaland, Kjetil; Vincent, Pierre; Rodriguez Vazquez, Pedro; Wiedner, Dirk; Yang, Shiming

    2017-08-01

    Silicon tracking detectors operated at high luminosity collider experiments pose a challenge for current and future readout systems regarding bandwidth, radiation, space and power constraints. With the latest developments in wireless communications, wireless readout systems might be an attractive alternative to commonly used wired optical and copper based readout architectures. The WADAPT group (Wireless Allowing Data and Power Transmission) has been formed to study the feasibility of wireless data transmission for future tracking detectors. These proceedings cover current developments focused on communication in the 60 GHz band. This frequency band offers a high bandwidth, a small form factor and an already mature technology. Motivation for wireless data transmission for high energy physics application and the developments towards a demonstrator prototype are summarized. Feasibility studies concerning the construction and operation of a wireless transceiver system have been performed. Data transmission tests with a transceiver prototype operating at even higher frequencies in the 240 GHz band are described. Data transmission at rates up to 10 Gb/s have been obtained successfully using binary phase shift keying.

  19. Alternative crops

    International Nuclear Information System (INIS)

    Andreasen, L.M.; Boon, A.D.

    1992-01-01

    Surplus cereal production in the EEC and decreasing product prices, mainly for cereals, has prompted considerable interest for new earnings in arable farming. The objective was to examine whether suggested new crops (fibre, oil, medicinal and alternative grains crops) could be considered as real alternatives. Whether a specific crop can compete economically with cereals and whether there is a market demand for the crop is analyzed. The described possibilities will result in ca. 50,000 hectares of new crops. It is expected that they would not immediately provide increased earnings, but in the long run expected price developments are more positive than for cereals. The area for new crops will not solve the current surplus cereal problem as the area used for new crops is only 3% of that used for cereals. Preconditions for many new crops is further research activities and development work as well as the establishment of processing units and organizational initiatives. Presumably, it is stated, there will then be a basis for a profitable production of new crops for some farmers. (AB) (47 refs.)

  20. Combined Effect of Alternating Current Interference and Cathodic Protection on Pitting Corrosion and Stress Corrosion Cracking Behavior of X70 Pipeline Steel in Near-Neutral pH Environment

    Directory of Open Access Journals (Sweden)

    Liwei Wang

    2018-03-01

    Full Text Available Influence of alternating current (AC on pitting corrosion and stress corrosion cracking (SCC behavior of X70 pipeline steel in the near-neutral pH environment under cathodic protection (CP was investigated. Both corrosion and SCC are inhibited by −0.775 VSCE CP without AC interference. With the superimposition of AC current (1–10 mA/cm2, the direct current (DC potential shifts negatively under the CP of −0.775 VSCE and the cathodic DC current decreases and shifts to the anodic direction. Under the CP potential of −0.95 VSCE and −1.2 VSCE, the applied AC current promotes the cathodic reaction and leads to the positive shift of DC potential and increase of cathodic current. Local anodic dissolution occurs attributing to the generated anodic current transients in the positive half-cycle of the AC current, resulting in the initiation of corrosion pits (0.6–2 μm in diameter. AC enhances the SCC susceptibility of X70 steel under −0.775 VSCE CP, attributing to the promotion of anodic dissolution and hydrogen evolution. Even an AC current as low as 1 mA/cm2 can enhance the SCC susceptibility.

  1. Draft environmental impact statement - BPA/Lower Valley transmission project

    International Nuclear Information System (INIS)

    1997-06-01

    Bonneville Power Administration and Lower Valley Power and Light, Inc., propose to solve a voltage stability problem in the Jackson and Afton, Wyoming areas. For the Agency Proposed Action, BPA and Lower Valley would construct a new 115-kV line from BPA's Swan Valley Substation near Swan Valley in Bonneville County, Idaho about 58 km (36 miles) east to BPA's Teton Substation near Jackson in Teton County, Wyoming. The new line would be next to an existing 115-kV line. Most of the line would be supported by a mix of single-circuit wood pole H-frame structures would be used. The Single-Circuit Line Alternative has all the components of the Agency Proposed Action except that the entire line would be supported by single-circuit structures. The Short Line Alternative has all the components of the Single-Circuit Line Alternative except it would then be removed. For the Static Var Compensation Alternative, BPA would install a Static Var Compensator (SVC) at Teton or Jackson Substation. An SVC is a group of electrical equipment placed at a substation to help control voltage on a transmission system. The No Action Alternative assumes that no new transmission line is built, and no other equipment is added to the transmission system. The USFS (Targhee and Bridger-Teton National Forests) must select al alternative based on their needs and objectives, decide if the project complies with currently approved forest plans, decide if special use permits or easements are needed for construction, operation, and maintenance of project facilities, and decide if they would issue special use permits and letters of consent to grant easements for the project

  2. HVDC power transmission technology assessment

    Energy Technology Data Exchange (ETDEWEB)

    Hauth, R.L.; Tatro, P.J.; Railing, B.D. [New England Power Service Co., Westborough, MA (United States); Johnson, B.K.; Stewart, J.R. [Power Technologies, Inc., Schenectady, NY (United States); Fink, J.L.

    1997-04-01

    The purpose of this study was to develop an assessment of the national utility system`s needs for electric transmission during the period 1995-2020 that could be met by future reduced-cost HVDC systems. The assessment was to include an economic evaluation of HVDC as a means for meeting those needs as well as a comparison with competing technologies such as ac transmission with and without Flexible AC Transmission System (FACTS) controllers. The role of force commutated dc converters was to be assumed where appropriate. The assessment begins by identifying the general needs for transmission in the U.S. in the context of a future deregulated power industry. The possible roles for direct current transmission are then postulated in terms of representative scenarios. A few of the scenarios are illustrated with the help of actual U.S. system examples. non-traditional applications as well as traditional applications such as long lines and asynchronous interconnections are discussed. The classical ``break-even distance`` concept for comparing HVDC and ac lines is used to assess the selected scenarios. The impact of reduced-cost converters is reflected in terms of the break-even distance. This report presents a comprehensive review of the functional benefits of HVDC transmission and updated cost data for both ac and dc system components. It also provides some provocative thoughts on how direct current transmission might be applied to better utilize and expand our nation`s increasingly stressed transmission assets.

  3. Transcending Transmission

    DEFF Research Database (Denmark)

    Schoeneborn, Dennis; Trittin, Hannah

    2013-01-01

    Purpose – Extant research on corporate social responsibility (CSR) communication primarily relies on a transmission model of communication that treats organizations and communication as distinct phenomena. This approach has been criticized for neglecting the formative role of communication...... in the emergence of organizations. This paper seeks to propose to reconceptualize CSR communication by drawing on the “communication constitutes organizations” (CCO) perspective. Design/methodology/approach – This is a conceptual paper that explores the implications of switching from an instrumental...... to a constitutive notion of communication. Findings – The study brings forth four main findings: from the CCO view, organizations are constituted by several, partly dissonant, and potentially contradictory communicative practices. From that viewpoint, the potential impact of CSR communication becomes a matter...

  4. Resonance of conductivity in UHF-range to the action of alternating current in La0.7Pb0.3MnO3 crystals

    International Nuclear Information System (INIS)

    Volkov, N.V.; Petrakovskij, G.A.; Sablina, K.A.

    1999-01-01

    The experimental results of the study on the effect of the low frequency transport current on the conductivity in UHF-range of the La 0.7 Pb 0.3 MnO 3 monocrystals are presented. In absence of the external magnetic field the UHF-conductivity response signal on the current impact has the form of the relaxation process. The peak of the amplitude resonance growth is observed in the external magnetic field in the response spectrum. The resonance response is of nonlinear character. The temperature and field dependences of the UHF-response basic parameters are in direct correlation with the magnetoresistance behaviour. The results obtained are analyzed within the frames of the oscillatory approximation. The mechanism of the phases electron separation is proposed as the possible mechanism of the current impact [ru

  5. 77 FR 35366 - Albany-Eugene Transmission Line Rebuild Project

    Science.gov (United States)

    2012-06-13

    ... materials, removing vegetation including danger trees, and revegetating areas disturbed by construction... implement the Proposed Action Alternative, based on the Albany-Eugene Transmission Line Rebuild Project (DOE...

  6. Transmission System Vegetation Management Program. Draft Environmental Impact Statement

    International Nuclear Information System (INIS)

    1999-01-01

    Bonneville is responsible for maintaining a network of 24,000 kilometers (km) or 15,000 miles (mi.) of electric transmission lines and 350 substations in a region of diverse vegetation. This vegetation can interfere with electric power flow, pose safety problems for Bonneville and the public, and interfere with their ability to maintain these facilities. They need to (1) keep vegetation away from the electric facilities; (2) increase their program efficiency and consistency; (3) review herbicide use (under increased public scrutiny); and (4) maximize the range of tools they can use while minimizing environmental impact (Integrated Vegetation Management). This DEIS establishes Planning Steps for managing vegetation for specific projects (to be tiered to this EIS). In addition to No Action (current practice), alternatives are presented for Rights-of-way, Electric Yards, and Non-electric Facilities (landscaping, work yards). Four vegetation control methods are analyzed: manual, mechanical, herbicide, and biological. Also evaluated are 24 herbicide active ingredients and 4 herbicide application techniques (spot, localized, broadcast, and aerial). For rights-of-way, they consider three sets of alternatives: alternative management approaches (time-driven or establishing low-growing plant communities); alternative method packages; and, if herbicides are in a methods package, alternative vegetation selections (noxious weeds, deciduous, or any vegetation). For electric yards, one herbicide-use alternative is considered. For non-electric facilities, two method package alternatives are considered. For rights-of-way, the environmentally preferred alternative(s) would use manual, mechanical, and biological control methods, as well as spot and localized herbicide applications for noxious and deciduous plant species; the BPA-preferred alternative(s) would add broadcast and aerial herbicide applications, and would use herbicides on any vegetation. Both would favor a management

  7. Energy Transmission and Infrastructure

    Energy Technology Data Exchange (ETDEWEB)

    Mathison, Jane

    2012-12-31

    The objective of Energy Transmission and Infrastructure Northern Ohio (OH) was to lay the conceptual and analytical foundation for an energy economy in northern Ohio that will: • improve the efficiency with which energy is used in the residential, commercial, industrial, agricultural, and transportation sectors for Oberlin, Ohio as a district-wide model for Congressional District OH-09; • identify the potential to deploy wind and solar technologies and the most effective configuration for the regional energy system (i.e., the ratio of distributed or centralized power generation); • analyze the potential within the district to utilize farm wastes to produce biofuels; • enhance long-term energy security by identifying ways to deploy local resources and building Ohio-based enterprises; • identify the policy, regulatory, and financial barriers impeding development of a new energy system; and • improve energy infrastructure within Congressional District OH-09. This objective of laying the foundation for a renewable energy system in Ohio was achieved through four primary areas of activity: 1. district-wide energy infrastructure assessments and alternative-energy transmission studies; 2. energy infrastructure improvement projects undertaken by American Municipal Power (AMP) affiliates in the northern Ohio communities of Elmore, Oak Harbor, and Wellington; 3. Oberlin, OH-area energy assessment initiatives; and 4. a district-wide conference held in September 2011 to disseminate year-one findings. The grant supported 17 research studies by leading energy, policy, and financial specialists, including studies on: current energy use in the district and the Oberlin area; regional potential for energy generation from renewable sources such as solar power, wind, and farm-waste; energy and transportation strategies for transitioning the City of Oberlin entirely to renewable resources and considering pedestrians, bicyclists, and public transportation as well as drivers

  8. Calculation of alternating current losses in stacks and coils made of second generation high temperature superconducting tapes for large scale applications

    DEFF Research Database (Denmark)

    Zermeno, Victor M. R.; Abrahamsen, Asger Bech; Mijatovic, Nenad

    2013-01-01

    A homogenization method to model a stack of second generation High Temperature Superconducting tapes under AC applied transport current or magnetic field has been obtained. The idea is to find an anisotropic bulk equivalent for the stack such that the geometrical layout of the internal alternatin...

  9. Direct current power delivery system and method

    Science.gov (United States)

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

    2016-09-06

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

  10. A computational model for determining the minimal cost expansion alternatives in transmission systems planning; Um modelo computacional para determinacao de alternativas de expansao de custo minimo em planejamento de sistemas de transmissao

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, L M.V.G.; Pereira, M V.F. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil); Nunes, A [ELETROBRAS, Rio de Janeiro, RJ (Brazil)

    1990-12-31

    A computational model for determining an economical transmission expansion plan, based in the decomposition techniques is presented. The algorithm was used in the Brazilian South System and was able to find an optimal solution, with a low computational resource. Some expansions of this methodology are been investigated: the probabilistic one and the expansion with financier restriction. (C.G.C.). 4 refs, 7 figs.

  11. Alternative Remedies

    Science.gov (United States)

    ... Home › Aging & Health A to Z › Alternative Remedies Font ... medical treatment prescribed by their healthcare provider. Using this type of alternative therapy along with traditional treatments is ...

  12. Alternative Fuels

    Science.gov (United States)

    Alternative fuels include gaseous fuels such as hydrogen, natural gas, and propane; alcohols such as ethanol, methanol, and butanol; vegetable and waste-derived oils; and electricity. Overview of alternative fuels is here.

  13. Alternating Hemiplegia

    Science.gov (United States)

    ... to the symptoms of the disorder. View Full Definition Treatment Drug therapy including verapamil may help to reduce the ... the more serious form of alternating hemiplegia × ... Definition Alternating hemiplegia is a rare neurological disorder that ...

  14. On the Impact of Electrostatic Correlations on the Double-Layer Polarization of a Spherical Particle in an Alternating Current Field.

    Science.gov (United States)

    Alidoosti, Elaheh; Zhao, Hui

    2018-05-15

    At concentrated electrolytes, the ion-ion electrostatic correlation effect is considered an important factor in electrokinetics. In this paper, we compute, in theory and simulation, the dipole moment for a spherical particle (charged, dielectric) under the action of an alternating electric field using the modified continuum Poisson-Nernst-Planck (PNP) model by Bazant et al. [ Double Layer in Ionic Liquids: Overscreening Versus Crowding . Phys. Rev. Lett. 2011 , 106 , 046102 ] We investigate the dependency of the dipole moment in terms of frequency and its variation with such quantities like ζ-potential, electrostatic correlation length, and double-layer thickness. With thin electric double layers, we develop simple models through performing an asymptotic analysis of the modified PNP model. We also present numerical results for an arbitrary Debye screening length and electrostatic correlation length. From the results, we find a complicated impact of electrostatic correlations on the dipole moment. For instance, with increasing the electrostatic correlation length, the dipole moment decreases and reaches a minimum and then it goes up. This is because of initially decreasing of surface conduction and finally increasing due to the impact of ion-ion electrostatic correlations on ion's convection and migration. Also, we show that in contrast to the standard PNP model, the modified PNP model can qualitatively explain the data from the experimental results in multivalent electrolytes.

  15. Note: Measuring breakdown characteristics during the hot re-ignition of high intensity discharge lamps using high frequency alternating current voltage.

    Science.gov (United States)

    van den Bos, R A J M; Sobota, A; Manders, F; Kroesen, G M W

    2013-04-01

    To investigate the cold and hot re-ignition properties of High Intensity Discharge (HID) lamps in more detail an automated setup was designed in such a way that HID lamps of various sizes and under different background pressures can be tested. The HID lamps are ignited with a ramped sinusoidal voltage signal with frequencies between 60 and 220 kHz and with amplitude up to 7.5 kV. Some initial results of voltage and current measurements on a commercially available HID lamp during hot and cold re-ignition are presented.

  16. Alternative laser system for cesium magneto-optical trap via optical injection locking to sideband of a 9-GHz current-modulated diode laser.

    Science.gov (United States)

    Diao, Wenting; He, Jun; Liu, Zhi; Yang, Baodong; Wang, Junmin

    2012-03-26

    By optical injection of an 852-nm extended-cavity diode laser (master laser) to lock the + 1-order sideband of a ~9-GHz-current-modulated diode laser (slave laser), we generate a pair of phase-locked lasers with a frequency difference up to ~9-GHz for a cesium (Cs) magneto-optical trap (MOT) with convenient tuning capability. For a cesium MOT, the master laser acts as repumping laser, locked to the Cs 6S₁/₂ (F = 3) - 6P₃/₂ (F' = 4) transition. When the + 1-order sideband of the 8.9536-GHz-current-modulated slave laser is optically injection-locked, the carrier operates on the Cs 6S₁/₂ (F = 4) - 6P₃/₂ (F' = 5) cooling cycle transition with -12 MHz detuning and acts as cooling/trapping laser. When carrying a 9.1926-GHz modulation signal, this phase-locked laser system can be applied in the fields of coherent population trapping and coherent manipulation of Cs atomic ground states.

  17. The current German regime governing third-party access to power transmission systems and denial of TPA, discussed from the angle of applicable civil law, energy industry law and antitrust law

    International Nuclear Information System (INIS)

    Kuehne, G.

    2000-01-01

    The German EnWG (energy industry law) for deregulation of the energy sector and implementation of the Internal Energy Market Directive of the EU contains an obligation to contract and make rules for establishing a legally binding system for access to and use of third parties of transmission and distribution networks in the competitive electricity market. The design of such contracts under private law as well as the grid code for network operation primarily being a matter of the contracting parties, the legal basis and opportunities for governmental supervisory functions are embodied in various laws. The legal analysis of this contribution examines the current situation and asks whether the existing provisions of the German BGB (Civil Code), antitrust law and the EnWG offer practicable means in case of need for governmental supervisory action in order to ensure evolution and adherence to a legal framework that will ensure the objectives of the politically willed deregulation of the energy sector and foster development of an open market serving the public welfare. (CB) [de

  18. An expert consortium review of the EC-commissioned report "alternative (Non-Animal) methods for cosmetics testing: current status and future prospects - 2010".

    Science.gov (United States)

    Hartung, Thomas; Blaauboer, Bas J; Bosgra, Sieto; Carney, Edward; Coenen, Joachim; Conolly, Rory B; Corsini, Emanuela; Green, Sidney; Faustman, Elaine M; Gaspari, Anthony; Hayashi, Makoto; Wallace Hayes, A; Hengstler, Jan G; Knudsen, Lisbeth E; Knudsen, Thomas B; McKim, James M; Pfaller, Walter; Roggen, Erwin L

    2011-01-01

    The European cosmetics legislation foresees a review in 2011 and possible postponement of the 2013 marketing ban to enforce the testing ban for systemic and repeated-dose animal tests. For this purpose, a 119-page report commissioned by the European Commission was published recently. Here, a group of 17 independent experts from the US, Europe, and Japan was brought together to evaluate the report. The expert panel strongly endorsed the report and its conclusions. A number of important options not considered were identified; these do not, however, affect the overall conclusions regarding the current lack of availability of a full replacement, especially for the areas of repeated dose toxicity, carcinogenicity testing, and reproductive toxicity, though a roadmap for change is emerging. However, some of these options may provide adequate data for replacement of some animal studies in the near future pending validation. Various recommendations expand the original report. The reviewers agree with the report that there is greater promise in the short term for the areas of sensitization and toxicokinetics. Additional opportunities lie in more global collaborations and the inclusion of other industry sectors.

  19. Towards a many-body theory for the combined elastic and inelastic transmission through a single molecule

    International Nuclear Information System (INIS)

    Petrov, E.G.

    2006-01-01

    Based on the nonequilibrium density matrix method, a unified approach to describe tunnel and sequential components of the current mediated by a molecule embedded in between the electrodes is proposed. It is shown that inelastic hopping processes not only form a sequential current component but simultaneously lead to molecular recharge. As the efficiency of a tunnel transmission depends strongly on a charge state of the molecule, the inelastic transfer processes can modify the elastic tunnel transmission via the alternation of the number of extra electrons at the molecule. Detailed analysis of the current-voltage characteristics has been carried out for a molecule with a single reaction level. The analytic expressions have been derived for both sequential (inelastic) and tunnel (elastic) current components, and the role of molecular recharge in the formation of specific transmission channels has been clarified

  20. Alternative wastewatersystems

    DEFF Research Database (Denmark)

    Dyck-Madsen, Søren; Hoffmann, Birgitte; Gabriel, Søren

    1999-01-01

    The report:-  Communicates experiences from Swedish buildings from the establishment and running of alternative wastewater systems. Communicates pictures of alternative buildings and wastewater systems in Sweden. Gives a short evaluation of the performance and the sustainability of the systems....

  1. Survey of Transmission Cost Allocation Methodologies for Regional Transmission Organizations

    Energy Technology Data Exchange (ETDEWEB)

    Fink, S.; Porter, K.; Mudd, C.; Rogers, J.

    2011-02-01

    The report presents transmission cost allocation methodologies for reliability transmission projects, generation interconnection, and economic transmission projects for all Regional Transmission Organizations.

  2. Local Multi-Channel RF Surface Coil versus Body RF Coil Transmission for Cardiac Magnetic Resonance at 3 Tesla: Which Configuration Is Winning the Game?

    Science.gov (United States)

    Weinberger, Oliver; Winter, Lukas; Dieringer, Matthias A; Els, Antje; Oezerdem, Celal; Rieger, Jan; Kuehne, Andre; Cassara, Antonino M; Pfeiffer, Harald; Wetterling, Friedrich; Niendorf, Thoralf

    2016-01-01

    The purpose of this study was to demonstrate the feasibility and efficiency of cardiac MR at 3 Tesla using local four-channel RF coil transmission and benchmark it against large volume body RF coil excitation. Electromagnetic field simulations are conducted to detail RF power deposition, transmission field uniformity and efficiency for local and body RF coil transmission. For both excitation regimes transmission field maps are acquired in a human torso phantom. For each transmission regime flip angle distributions and blood-myocardium contrast are examined in a volunteer study of 12 subjects. The feasibility of the local transceiver RF coil array for cardiac chamber quantification at 3 Tesla is demonstrated. Our simulations and experiments demonstrate that cardiac MR at 3 Tesla using four-channel surface RF coil transmission is competitive versus current clinical CMR practice of large volume body RF coil transmission. The efficiency advantage of the 4TX/4RX setup facilitates shorter repetition times governed by local SAR limits versus body RF coil transmission at whole-body SAR limit. No statistically significant difference was found for cardiac chamber quantification derived with body RF coil versus four-channel surface RF coil transmission. Our simulation also show that the body RF coil exceeds local SAR limits by a factor of ~2 when driven at maximum applicable input power to reach the whole-body SAR limit. Pursuing local surface RF coil arrays for transmission in cardiac MR is a conceptually appealing alternative to body RF coil transmission, especially for patients with implants.

  3. Ameloginins promote an alternatively activated macrophage phenotype in vitro

    DEFF Research Database (Denmark)

    Almqvist, S; Werthen, M; Lyngstadas, SP

    2011-01-01

    aggregates were visualised by transmission electron microscopy. The amelogenin treatment of macrophages increased several pro- and anti-inflammatory cytokines, including alternative macrophage activation marker AMAC-1 (p

  4. How alternative are alternative fuels?

    OpenAIRE

    Soffritti, Tiziana; Danielis, Romeo

    1998-01-01

    Could alternative fuel vehicles contribute to a substantial reduction of air pollution? Is there a market for alternative fuel vehicles? Could a market be created via a pollution tax? The article answers these questions on the basis of the available estimates.

  5. Alternative detox.

    Science.gov (United States)

    Ernst, E

    2012-01-01

    The concept that alternative therapies can eliminate toxins and toxicants from the body, i.e. 'alternative detox' (AD) is popular. Selected textbooks and articles on the subject of AD. The principles of AD make no sense from a scientific perspective and there is no clinical evidence to support them. The promotion of AD treatments provides income for some entrepreneurs but has the potential to cause harm to patients and consumers. In alternative medicine, simplistic but incorrect concepts such as AD abound. AREAS TIMELY FOR RESEARCH: All therapeutic claims should be scientifically tested before being advertised-and AD cannot be an exception.

  6. Speed controller for an alternating - current motor

    International Nuclear Information System (INIS)

    Bolie, V.W.

    1984-01-01

    A controller for a multi-phase ac motor that is subject to a large inertial load, e.g. an induction motor driving a heavy spinning rotor of a neutron chopper that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal Esub(L) having a meandering line frequency, includes a sensor which provides a feedback pulse train representative of the actual speed of the motor which is compared (by counting clock pulses between feedback pulses) with a reference clock signal in a computing unit to provide a motor control signal Esub(c). The motor control signal is a weighted linear sum of a speed error signal, a phase error signal, and a drift error signal, the magnitudes of which are recalculated and updated with each revolution of the motor shaft. The speed error signal is constant for large speed errors but highly sensitive to small speed errors. The stator windings of the motor are driven by variable-frequency power amplifiers which are controlled by the motor control signal Esub(c) via PROMs which store digital representations of sine and cosine waveforms in quadrature. (author)

  7. Biocorrosion control: Current strategies and promising alternatives ...

    African Journals Online (AJOL)

    Metal corrosion is an electrochemical reaction between the environment and a metal, in which microbes are thought to play a very important role. The rates at which various types of metals corrode are dependent upon environmental conditions as well as on the type of metals. The most well studied bacteria involved in ...

  8. Incorporating future change into current conservation planning: Evaluating tidal saline wetland migration along the U.S. Gulf of Mexico coast under alternative sea-level rise and urbanization scenarios

    Science.gov (United States)

    Enwright, Nicholas M.; Griffith, Kereen T.; Osland, Michael J.

    2015-11-02

    In this study, the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, quantified the potential for landward migration of tidal saline wetlands along the U.S. Gulf of Mexico coast under alternative future sea-level rise and urbanization scenarios. Our analyses focused exclusively on tidal saline wetlands (that is, mangrove forests, salt marshes, and salt flats), and we combined these diverse tidal saline wetland ecosystems into a single grouping, “tidal saline wetland.” Collectively, our approach and findings can provide useful information for scientists and environmental planners working to develop future-focused adaptation strategies for conserving coastal landscapes and the ecosystem goods and services provided by tidal saline wetlands. The primary product of this work is a public dataset that identifies locations where landward migration of tidal saline wetlands is expected to occur under alternative future sea-level rise and urbanization scenarios. In addition to identifying areas where landward migration of tidal saline wetlands is possible because of the absence of barriers, these data also identify locations where landward migration of these wetlands could be prevented by barriers associated with current urbanization, future urbanization, and levees.

  9. Catching lightning for alternative energy

    Energy Technology Data Exchange (ETDEWEB)

    Helman, D.S. [California State University, Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840 (United States)

    2011-05-15

    The article reviews the current literature related to lightning and makes a case for using lightning as an alternative source of energy. Objections to using lightning as an alternative source of energy are listed. Current literature is reviewed and articles are suggested as useful for building a tower, or using rockets or lasers to target a strike, or for quantifying a lightning strike. (author)

  10. Transmission access issues: Present and future

    International Nuclear Information System (INIS)

    Bahl, P.K.; Gray, R.G.

    1992-01-01

    In recent years, the electric industry has undergone dramatic changes as the federal and state governments have encouraged bulk power production by Independent Power Producers (IPPS) and Qualified Facilities (QFs). With decentralization and the consequent competition in the field of bulk power production, there has emerged the problem of non-utility generators (NUGS) and of transmission dependent utilities accessing the existing transmission systems owned by electric utilities. This paper presents current and future issues related to transmission access by IPPS, QFs and transmission dependent utilities. These issues include: (a) impact on system reliability, (b) impact of pricing strategies, (c) changes in state and federal regulations, (d) transmission proposals by various entities, (e) present access arrangements, (f) formation of the Western Systems Power Pool (WSPP), and (g) siting difficulties. The transmission access problem warrants consideration of transmission services, coordination among electric utilities, joint planning on a regional basis, and accommodation of IPPs and NUGs

  11. Wireless power transmission for battery charging

    Science.gov (United States)

    Mi, Chris; Li, Siqi; Nguyen, Trong-Duy; Wang, Junhua; Li, Jiangui; Li, Weihan; Xu, Jun

    2016-11-15

    A wireless power transmission system is provided for high power applications. The power transmission system is comprised generally of a charging unit configured to generate an alternating electromagnetic field and a receive unit configured to receive the alternating electromagnetic field from the charging unit. The charging unit includes a power source; an input rectifier; an inverter; and a transmit coil. The transmit coil has a spirangle arrangement segmented into n coil segments with capacitors interconnecting adjacent coil segments. The receive unit includes a receive coil and an output rectifier. The receive coil also has a spirangle arrangement segmented into m coil segments with capacitors interconnecting adjacent coil segments.

  12. Integrated approach to transmission services pricing

    International Nuclear Information System (INIS)

    Yu, C.W.; David, A.K.

    1999-01-01

    The paper presents an intuitively logical split between: (a) embedded, (b) operating, and (c) expansion cost based pricing and methodologies for implementation, for transmission services. A conceptually straightforward mechanism for the equitable allocation of transmission network embedded cost recovery based on capacity-use and reliability benefit is proposed, expansion cost is charged on a long-run marginal cost basis and finally, operating cost recovery is based on short-run marginal pricing. This is followed by co-ordinating these alternatives and integrating the pricing mechanisms to achieve appropriate price signals for bulk power users of transmission systems. (author)

  13. IGMtransmission: Transmission curve computation

    Science.gov (United States)

    Harrison, Christopher M.; Meiksin, Avery; Stock, David

    2015-04-01

    IGMtransmission is a Java graphical user interface that implements Monte Carlo simulations to compute the corrections to colors of high-redshift galaxies due to intergalactic attenuation based on current models of the Intergalactic Medium. The effects of absorption due to neutral hydrogen are considered, with particular attention to the stochastic effects of Lyman Limit Systems. Attenuation curves are produced, as well as colors for a wide range of filter responses and model galaxy spectra. Photometric filters are included for the Hubble Space Telescope, the Keck telescope, the Mt. Palomar 200-inch, the SUBARU telescope and UKIRT; alternative filter response curves and spectra may be readily uploaded.

  14. Cosmic alternatives?

    Science.gov (United States)

    Gregory, Ruth

    2009-04-01

    "Cosmologists are often in error but never in doubt." This pithy characterization by the Soviet physicist Lev Landau sums up the raison d'être of Facts and Speculations in Cosmology. Authors Jayant Narlikar and Geoffrey Burbidge are proponents of a "steady state" theory of cosmology, and they argue that the cosmological community has become fixated on a "Big Bang" dogma, suppressing alternative viewpoints. This book very much does what it says on the tin: it sets out what is known in cosmology, and puts forward the authors' point of view on an alternative to the Big Bang.

  15. The pathogen transmission avoidance theory of sexual selection

    Energy Technology Data Exchange (ETDEWEB)

    Loehle, C.

    1997-08-01

    The current theory that sexual selection results from female preference for males with good genes suffers from several problems. An alternative explanation, the pathogen transmission avoidance hypothesis, argues that the primary function of showy traits is to provide a reliable signal of current disease status, so that sick individuals can be avoided during mating. This study shows that a significant risk of pathogen transmission occurs during mating and that showy traits are reliable indicators of current disease status. The origin of female choosiness is argued to lie in a general tendency to avoid sick individuals, even in the absence of showy traits, which originate as exaggerations of normal traits that are indicative of good health (bright feathers, vigorous movement, large size). Thus, in this new model the origins of both showy traits and female choosiness are not problematic and there is no threshold effect. This model predicts that when the possession of male showy traits does not help to reduce disease in the female, showy traits are unlikely to occur. This case corresponds to thorough exposure of every animal to all group pathogens, on average, in large groups. Such species are shown with a large data set on birds to be less likely to exhibit showy traits. The good-genes model does not make this prediction. The pathogen transmission avoidance model can also lead to the evolution of showy traits even when selection is not effective against a given pathogen (e.g., when there is no heritable variation for resistance), but can result in selection for resistance if such genes are present. Monogamy is argued to reduce selection pressures for showy traits; data show monogamous species to be both less parasitized and less showy. In the context of reduction of pathogen transmission rates in showy populations, selection pressure becomes inversely frequency-dependent, which makes showy traits likely to be self-limiting rather than runaway.

  16. Investigation of an alternating current plasma as an element selective atomic emission detector for high-resolution capillary gas chromatography and as a source for atomic absorption and atomic emission spectrometry

    Science.gov (United States)

    Ombaba, Jackson M.

    This thesis deals with the construction and evaluation of an alternating current plasma (ACP) as an element-selective detector for high resolution capillary gas chromatography (GC) and as an excitation source for atomic absorption spectrometry (AAS) and atomic emission spectrometry (AES). The plasma, constrained in a quartz discharge tube at atmospheric pressure, is generated between two copper electrodes and utilizes helium as the plasma supporting gas. The alternating current plasma power source consists of a step-up transformer with a secondary output voltage of 14,000 V at a current of 23 mA. The device exhibits a stable signal because the plasma is self-seeding and reignites itself every half cycle. A tesla coil is not required to commence generation of the plasma if the ac voltage applied is greater than the breakdown voltage of the plasma-supporting gas. The chromatographic applications studied included the following: (1) the separation and selective detection of the organotin species, tributyltin chloride (TBT) and tetrabutyltin (TEBT), in environmental matrices including mussels (Mvutilus edullus) and sediment from Boston Harbor, industrial waste water and industrial sludge, and (2) the detection of methylcyclopentadienyl manganesetricarbonyl (MMT) and similar compounds used as gasoline additives. An ultrasonic nebulizer (common room humidifier) was utilized as a sample introduction device for aqueous solutions when the ACP was employed as an atomization source for atomic absorption spectrometry and as an excitation source for atomic emission spectrometry. Plasma diagnostic parameters studied include spatial electron number density across the discharge tube, electronic, excitation and ionization temperatures. Interference studies both in absorption and emission modes were also considered. Figures of merits of selected elements both in absorption and emission modes are reported. The evaluation of a computer-aided optimization program, Drylab GC, using

  17. Growing Alternatives

    DEFF Research Database (Denmark)

    Bagger-Petersen, Mai Corlin

    2014-01-01

    From 2014, Anhui Province will pilot a reform of the residential land market in China, thus integrating rural Anhui in the national housing market. In contrast, artist and activist Ou Ning has proposed the Bishan time money currency, intending to establish an alternative economic circuit in Bishan...

  18. Alternative Veier

    DEFF Research Database (Denmark)

    Kruse, Tove Elisabeth; Salamonsen, Anita

    reflektioner omkring patienters brug af og erfaringer med alternativ behandling. Patientorganisationer, organisatoner for alternative behandlere og organisationer for læger og medicinstuderende har læst bogens patienthistorier og deres perspektiver lægges frem. Til slut i bogen diskuteres betydningen af de...

  19. Alternatives to Traditional Notation.

    Science.gov (United States)

    Gaare, Mark

    1997-01-01

    Provides a introduction and overview to alternative music notation systems. Describes guitar tablature, accordion tablature, klavarskribo (a keyboard notational system developed by Cornelius Pot, a Dutch engineer), and the digital piano roll. Briefly discusses the history of notation reform and current efforts. Includes examples from scores. (MJP)

  20. Adjustable direct current and pulsed circuit fault current limiter

    Science.gov (United States)

    Boenig, Heinrich J.; Schillig, Josef B.

    2003-09-23

    A fault current limiting system for direct current circuits and for pulsed power circuit. In the circuits, a current source biases a diode that is in series with the circuits' transmission line. If fault current in a circuit exceeds current from the current source biasing the diode open, the diode will cease conducting and route the fault current through the current source and an inductor. This limits the rate of rise and the peak value of the fault current.

  1. Exploiting a Transmission Grating Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Ronald E. Bell

    2004-12-08

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics.

  2. Exploiting a Transmission Grating Spectrometer

    International Nuclear Information System (INIS)

    Bell, Ronald E.

    2004-01-01

    The availability of compact transmission grating spectrometers now allows an attractive and economical alternative to the more familiar Czerny-Turner configuration for many high-temperature plasma applications. Higher throughput is obtained with short focal length refractive optics and stigmatic imaging. Many more spectra can be obtained with a single spectrometer since smaller, more densely packed optical input fibers can be used. Multiple input slits, along with a bandpass filter, can be used to maximize the number of spectra per detector, providing further economy. Curved slits can correct for the strong image curvature of the short focal length optics. Presented here are the governing grating equations for both standard and high-dispersion transmission gratings, defining dispersion, image curvature, and desired slit curvature, that can be used in the design of improved plasma diagnostics

  3. Fundamental study of bulk power HVDC transmission

    International Nuclear Information System (INIS)

    1981-01-01

    Study on the HVDC power transmission have been conducted since 1956. Shinshinano-Frequency Changer had been operated at first on 1977, as our home product, and Hokkaido-Honshu DC transmission also realized at 1979. Research and Development of the bulk power HVDC have been promoted by the UHV transmission special committee in our Institute from 1980. This paper is a comprehensive report published in the parts of operating control, insulation of DC line and countermeasure of fault current, and interferences in order to contribute for planning, design and operating of the UHV DC transmission in future. (author)

  4. Experimental Investigation of the Corona Discharge in Electrical Transmission due to AC/DC Electric Fields

    Directory of Open Access Journals (Sweden)

    Fuangpian Phanupong

    2016-01-01

    Full Text Available Nowadays, using of High Voltage Direct Current (HVDC transmission to maximize the transmission efficiency, bulk power transmission, connection of renewable power source from wind farm to the grid is of prime concern for the utility. However, due to the high electric field stress from Direct Current (DC line, the corona discharge can easily be occurred at the conductor surface leading to transmission loss. Therefore, the polarity effect of DC lines on corona inception and breakdown voltage should be investigated. In this work, the effect of DC polarity and Alternating Current (AC field stress on corona inception voltage and corona discharge is investigated on various test objects, such as High Voltage (HV needle, needle at ground plane, internal defect, surface discharge, underground cable without cable termination, cable termination with simulated defect and bare overhead conductor. The corona discharge is measured by partial discharge measurement device with high-frequency current transformer. Finally, the relationship between supply voltage and discharge intensity on each DC polarity and AC field stress can be successfully determined.

  5. Space power transmission

    Energy Technology Data Exchange (ETDEWEB)

    Kuribayashi, Shizuma [Mitsubishi Heavy Industries, Ltd., Tokyo, (Japan)

    1989-10-05

    There being a conception to utilize solar energy by use of a space power station (SPS), a method to bring that universal grace to mankind is wireless energy transmission. The wireless energy transmission is regarded to be microwave transmission or laser beam transmission. The microwave transmission is to transmit 2.45GHz band microwave from the SPS to a receiving station on the ground to meet power demand on earth. The microwave, as small in attenuation in atmosphere and resistant against rain and cloud, is made candidate and, however, problematic in influence on organism, necessary large area of receiving antenna and many other points to be studied. While the laser transmission, as more convergent of beam than the microwave transmission, is advantageous with enabling the receiving area to be small and, however, disadvantageous with being not resistant against dust, rain and cloud, if used for the energy transmission between the space and earth. 2 refs., 2 figs.

  6. Transmission on Balance 2006

    International Nuclear Information System (INIS)

    2007-02-01

    Every year he Dutch Transmission System Operator (TSO) TenneT issues the title publication 'Transmission on Balance'. This report provides information about the main technical operating results in the past year.

  7. Plasmodium vivax Transmission in Africa.

    Directory of Open Access Journals (Sweden)

    Rosalind E Howes

    2015-11-01

    Full Text Available Malaria in sub-Saharan Africa has historically been almost exclusively attributed to Plasmodium falciparum (Pf. Current diagnostic and surveillance systems in much of sub-Saharan Africa are not designed to identify or report non-Pf human malaria infections accurately, resulting in a dearth of routine epidemiological data about their significance. The high prevalence of Duffy negativity provided a rationale for excluding the possibility of Plasmodium vivax (Pv transmission. However, review of varied evidence sources including traveller infections, community prevalence surveys, local clinical case reports, entomological and serological studies contradicts this viewpoint. Here, these data reports are weighted in a unified framework to reflect the strength of evidence of indigenous Pv transmission in terms of diagnostic specificity, size of individual reports and corroboration between evidence sources. Direct evidence was reported from 21 of the 47 malaria-endemic countries studied, while 42 countries were attributed with infections of visiting travellers. Overall, moderate to conclusive evidence of transmission was available from 18 countries, distributed across all parts of the continent. Approximately 86.6 million Duffy positive hosts were at risk of infection in Africa in 2015. Analysis of the mechanisms sustaining Pv transmission across this continent of low frequency of susceptible hosts found that reports of Pv prevalence were consistent with transmission being potentially limited to Duffy positive populations. Finally, reports of apparent Duffy-independent transmission are discussed. While Pv is evidently not a major malaria parasite across most of sub-Saharan Africa, the evidence presented here highlights its widespread low-level endemicity. An increased awareness of Pv as a potential malaria parasite, coupled with policy shifts towards species-specific diagnostics and reporting, will allow a robust assessment of the public health

  8. Energy alternatives

    International Nuclear Information System (INIS)

    Sweet, C.

    1987-01-01

    The designated successor to fossil fuels is nuclear fission/fusion and that turns out to be problematic. Alternative Energy Systems have great potential but political forces seem to be hampering their development and introduction. The technologies are flexible in their use and scale of operation. The learning curve will not be short but neither will it be as long and as costly as nuclear power. It is time that this is recognised and some serious rethinking takes place in what presently passes for energy policies both in the industrialised countries and in the Third World. Alternative energy systems are defined and some of them which are relevant to the United Kingdom are discussed. (author)

  9. The transmission of differing energy beta particles through various materials

    International Nuclear Information System (INIS)

    Quayle, D.R.

    1996-04-01

    The transmission of beta particles is frequently calculated in the same fashion as that of gamma rays, where the mass attenuation coefficient is defined by the slope of the exponential function. Numerous authors have used this approximation including Evans (1955), Loevinger (1952), and Chabot et. al. (1988). Recent work by McCarthy et. al. (1995) indicated that the exponential function seemed to fit well over a particular region of the transmission curve. Upon further investigation, the author decided to verify McCarthy's results by the use of different absorber materials and attempt to reproduce the experiments. A theoretical method will be used to estimate the transmission of the beta particles through the three absorbers, aluminum, zirconium, and iron. An alternate Monte Carlo code, the Electron Gamma Shower version 4 code (EGS4) will also be used to verify that the experiment is approximating a pencil beam of beta particles. Although these two methods offer a good cross check for the experimental data, they pose a conflict in regards to the type of beam that is to be generated. The experimental lab setup uses a collimated beam of electrons that will impinge upon the absorber, while the codes are written using a pencil beam. A minor discrepancy is expected to be observed in the experimental results and is currently under investigation by McCarthy. The results of this project supported the theory that the beta mass attenuation coefficient was accurately represented by the slope of an exponential function, but only for that particular region of the transmission curve that has a minimal absorber thickness. By fitting the data beyond 50% of the beta particle range this theory does not hold true. The theory generated by McCarthy (1995) and the EGS4 Monte Carlo code indicated that the transmission curve for a pencil beam was not accurately represented by an exponential function. The results of this experiment appeared to provide additional support to this assumption

  10. Transmission policy in the United States

    International Nuclear Information System (INIS)

    Joskow, P.L.

    2005-01-01

    This paper provides an overview of the development of electric power transmission access, pricing and investment policies in the US over the last 15 years and evaluates the current state of those policies. Pre-liberalization transmission access and pricing policies are reviewed first since more recent policies have evolved from them. FERC's efforts to ensure that transmission owning utilities provide non-discriminatory access and pricing to wholesale transmission customers, culminating in Order 888 and 889 are discussed. These rules did not respond to problems created by a highly balkanized transmission system and only partially responded to problems caused by common ownership and operation of transmission networks with generating and marketing businesses in the same regions. These problems motivated FERC to seek to create Regional Transmission Organizations (RTO) meeting a long list of criteria related to governance, network operations, transmission pricing and investment as reflected in Order 2000. The slow pace of 'voluntary' reform following Order 2000 led FERC to issue a proposed Standard Market Design Rule (SMD) which provided more detailed prescriptions for wholesale market design, network operations, regional planning, resource adequacy, and transmission investment. The SMD rule confronted enormous resistance from groups of utilities and states that had not embraced an electricity sector liberalization agenda. However, many of the provisions of the SMD are being implemented by the RTOs and ISOs in the Northeast and Midwest. PJM's market rules and transmission pricing, planning and investment policies are reviewed as an articulation of FERC's RTO and SMD visions. (author)

  11. Alternative drugs of abuse.

    Science.gov (United States)

    Sutter, M E; Chenoweth, J; Albertson, T E

    2014-02-01

    The incidence of drug abuse with alternative agents is increasing. The term "alternative drugs of abuse" is a catch-all term for abused chemicals that do not fit into one of the classic categories of drugs of abuse. The most common age group abusing these agents range from 17 to 25 years old and are often associated with group settings. Due to their diverse pharmacological nature, legislative efforts to classify these chemicals as a schedule I drug have lagged behind the development of new alternative agents. The potential reason for abuse of these agents is their hallucinogenic, dissociative, stimulant, anti-muscarinic, or sedative properties. Some of these drugs are easily obtainable such as Datura stramonium (Jimson Weed) or Lophophora williamsii (Peyote) because they are natural plants indigenous to certain regions. The diverse pharmacology and clinical effects of these agents are so broad that they do not produce a universal constellation of signs and symptoms. Detailed physical exams are essential for identifying clues leading one to suspect an alternative drug of abuse. Testing for the presence of these agents is often limited, and even when available, the results do not return in a timely fashion. Intoxications from these agents pose unique challenges for health care providers. Physician knowledge of the physiological effects of these alternative agents and the local patterns of drug of abuse are important for the accurate diagnosis and optimal care of poisoned patients. This review summarizes the current knowledge of alternative drugs of abuse and highlights their clinical presentations.

  12. Alternative Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    West, M.; Duckers, L.; Lockett, P.; Loughridge, B.; Peatfield, T.; White, P.

    1984-01-01

    The Coventry (Lanchester) Polytechnic Wave Energy Group has been involved in the United Kingdom wave energy research programme since its inception in 1975. Whilst the work of the group is mainly concerned with wave energy, and currently is directed towards the design of a wave energy device tailored to the needs of isolated/island communities, it has some involvement with other aspects of the alternatives. This conference, dealing with alternative energy systems and their electrical integration and utilisation was engendered by the general interest which the Polytechnic group members have in the alternatives and their use. The scope for electrical integration and utilisation is very broad. Energy for family groups may be provided in a relatively unsophisticated way which is acceptable to them. Small population centres, for example island communities relying upon diesel equipment, can reap the benefits of the alternatives through their ability to accept novel integration schemes and a flexible approach to the use of the energy available. Consumers already enjoying the benefits of a 'firm' electricity grid supply can use energy from a variety of alternative systems, via the grid, without having to modify their energy consumption habits. In addition to the domestic and industrial applications and coastal possibilities, specialist applications in isolated environments have also emerged. The Proceedings detail practical, technical and economic aspects of the alternatives and their electrical integration and utilisation.

  13. Radioactive waste management alternatives

    International Nuclear Information System (INIS)

    Baranowski, F.P.

    1976-01-01

    The information in the US ERDA ''Technical Alternatives Document'' is summarized. The first two points show that waste treatment, interim storage and transportation technologies for all wastes are currently available. Third, an assessment of integrated waste management systems is needed. One such assessment will be provided in our expanded waste management environmental statement currently planned for release in about one year. Fourth, geologies expected to be suitable for final geologic storage are known. Fifth, repository system assessment methods, that is a means to determine and assess the acceptability of a terminal storage facility for nonretrievable storage, must and will be prepared. Sixth, alternatives to geologic storage are not now available. Seventh, waste quantities and characteristics are sensitive to technologies and fuel-cycle modes, and therefore an assessment of these technologies and modes is important. Eighth, and most important, it is felt that the LWR fuel cycle can be closed with current technologies

  14. Current status and future prospects of research and development operations in traditional and complementary and alternative medicine manufacturing small- and medium-sized enterprises: a 2014 company-based survey.

    Science.gov (United States)

    Ahn, Miyoung; Park, Eun-Ji; Woo, Jong-Min

    2017-12-01

    Small- and medium-sized enterprises (SMEs) have played key roles in the economic growth and technical innovation of traditional and complementary and alternative medicine (T&CM). Research and development (R&D) are critical activities for industrial progress. This study aimed to characterize the current status of SME R&D activities and to explore manufacturers' perceptions of R&D expansion. Records of the distribution of T&CM SMEs and R&D resources detailed in the 2014 Statistics of Korea T&CM Industries survey, a previously conducted survey on the industrial status of the T&CM field, were reviewed. Data on the perceptions of R&D activities were investigated through a company-based survey covering 285 T&CM-manufacturing SMEs. Greater than 99% of the 13,636 T&CM manufacturers at the time of the study were SMEs employing less than 50 workers. Natural cosmetics manufacturing SMEs (NC SMEs) had the highest R&D expenditures. NC SMEs rely heavily on internal R&D operations, which may contribute to their strong need for R&D collaboration with public research institutions and expanded T&CM-promoted R&D programs. "Digestive system disorders" are the main target diseases for current herbal and dietary supplement manufacturing SMEs and herbal medicine manufacturing SMEs. These SMEs tend to view their own product-related business as a priority for future R&D investment. This study represents the first attempt to assess SME perceptions of R&D activities. The findings herein can inform the design of sustainable programs that support R&D by reducing the gaps between the perspectives of T&CM product makers and policymakers.

  15. Current status and future prospects of research and development operations in traditional and complementary and alternative medicine manufacturing small- and medium-sized enterprises: a 2014 company-based survey

    Directory of Open Access Journals (Sweden)

    Miyoung Ahn

    2017-12-01

    Full Text Available Background: Small- and medium-sized enterprises (SMEs have played key roles in the economic growth and technical innovation of traditional and complementary and alternative medicine (T&CM. Research and development (R&D are critical activities for industrial progress. This study aimed to characterize the current status of SME R&D activities and to explore manufacturers’ perceptions of R&D expansion. Methods: Records of the distribution of T&CM SMEs and R&D resources detailed in the 2014 Statistics of Korea T&CM Industries survey, a previously conducted survey on the industrial status of the T&CM field, were reviewed. Data on the perceptions of R&D activities were investigated through a company-based survey covering 285 T&CM-manufacturing SMEs. Results: Greater than 99% of the 13,636 T&CM manufacturers at the time of the study were SMEs employing less than 50 workers. Natural cosmetics manufacturing SMEs (NC SMEs had the highest R&D expenditures. NC SMEs rely heavily on internal R&D operations, which may contribute to their strong need for R&D collaboration with public research institutions and expanded T&CM-promoted R&D programs. “Digestive system disorders” are the main target diseases for current herbal and dietary supplement manufacturing SMEs and herbal medicine manufacturing SMEs. These SMEs tend to view their own product-related business as a priority for future R&D investment. Conclusion: This study represents the first attempt to assess SME perceptions of R&D activities. The findings herein can inform the design of sustainable programs that support R&D by reducing the gaps between the perspectives of T&CM product makers and policymakers. Keywords: R&D, SME, South Korea, survey, T&CM

  16. Alternative pricing methodologies

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    With the increased interest in competitive market forces and growing recognition of the deficiencies in current practices, FERC and others are exploring alternatives to embedded cost pricing. A number of these alternatives are discussed in this chapter. Marketplace pricing, discussed briefly here, is the subject of the next chapter. Obviously, the pricing formula may combine several of these methodologies. One utility of which the authors are aware is seeking a price equal to the sum of embedded costs, opportunity costs, line losses, value of service, FERC's percentage adder formula and a contract service charge

  17. The automotive transmission book

    CERN Document Server

    Fischer, Robert; Jürgens, Gunter; Najork, Rolf; Pollak, Burkhard

    2015-01-01

    This book presents essential information on systems and interactions in automotive transmission technology and outlines the methodologies used to analyze and develop transmission concepts and designs. Functions of and interactions between components and subassemblies of transmissions are introduced, providing a basis for designing transmission systems and for determining their potentials and properties in vehicle-specific applications: passenger cars, trucks, buses, tractors, and motorcycles. With these fundamentals the presentation provides universal resources for both state-of-the-art and future transmission technologies, including systems for electric and hybrid electric vehicles.

  18. Alternative detente

    International Nuclear Information System (INIS)

    Soper, K.; Ryle, M.

    1988-01-01

    The influence of the Chernobyl accident on the disarmament and anti-nuclear movements is discussed. The accident directed attention towards the areas in common rather than the areas of disagreement. It also demonstrated the environmental impact of radioactivity, strengthening the ecological case of the anti-nuclear movement. The issues are discussed for the Western and Eastern bloc countries and the relationship between the two. Sections focus on the Eco-protest, Green politics and economics and on the politics of minority protest and the Green alternative. (U.K.)

  19. Injertos óseos: Una alternativa efectiva y actual para la reconstrucción del complejo cráneo-facial BONE GRAFTS: AN EFFECTIVE AND CURRENT ALTERNATIVE FOR THE RECONSTRUCTION OF THE CRANIOFACIAL COMPLEX

    Directory of Open Access Journals (Sweden)

    Sergio Soto Góngora

    2005-04-01

    regeneration process, which makes them inert biocompatible "filling" materials that do not substitute the characteristics of the grafts, but they can improve the results if they are used together. The present paper recommends the use of bone grafts as a viable, effective and current alternative as regards reconstruction.

  20. Canadians trying to join US transmission groups

    International Nuclear Information System (INIS)

    Bright, David; Salaff, Stephen.

    1994-01-01

    Various competition problems faced by Canadian utilities and attempts to solve them, were described. E.g. B.C. Hydro and its electricity trade subsidiary Powerex have moved to become members of the Western Regional Transmission Association (WRTA), an association of about 40 utilities which serve part of the western United States. Through the WRTA, Powerex seeks fair terms to ensure its access to the U.S. market. Membership allows fast dispute resolution and enhances sales to California and other western states. Concern was expressed by the U.S Dept.of Energy about the lack of reciprocity.In the year ending March 1994, Powerex exported 2,600 gigawatt-hours of electricity, over 90% to the U.S. This was a l ow water year for hydroelectric-based BC Hydro, in which surplus energy available for export was only about half of what is usually available. Ontario Hydro and other provincially owned utilities were said to be challenged by U.S. industry deregulation and open transmission policies. If Canadian utilities fail to initiate structural changes leading to open access policies, their economic competitiveness may well decline. If on the other hand Canadian utilities decided to adopt open access policies, they would need to shed their monopolistic practices and accelerate restructuring in the face of wholesale competition. They could face direct retail competition in their currently captive provincial markets from U.S. and alternative Canadian suppliers. In an open competition scenario up to 20% of Ontario Hydro's domestic sales were said to be in danger of being displaced by imports from New York and Michigan

  1. Financing investment in the European electricity transmission network: Consequences on long-term sustainability of the TSOs financial structure

    International Nuclear Information System (INIS)

    Henriot, Arthur

    2013-01-01

    This article focuses on the ability of European TSOs to meet the demand for substantial investments in the electricity transmission grid over the next two decades. We employ quantitative analysis to assess the impact of the required capital expenditures under a set of alternative financing strategies. We consider a best-case scenario of full cooperation between the European TSOs. It appears that under current trends in the evolution of transmission tariffs, only half the volumes of investment currently planned could be funded. A highly significant increase in transmission tariffs will be required to ensure the whole-scale investments can be delivered. Finally, alternative strategies can dampen the impact on tariffs but they can only partially substitute for this increase in charges paid by network users. -- Highlights: •We applied balance-sheet modelling to a single European Electricity TSO. •Investments planned will not be achievable under current tariffs evolution. •A three-fold higher growth of transmission network tariffs would be necessary. •New financing strategies can dampen the impact on tariffs, to a minor extent

  2. Wireless transmission: state of research, applications, trends

    International Nuclear Information System (INIS)

    Berger, A.

    2016-01-01

    At the end of the 19th century Nikola Tesla started his work in the field of wireless energy transmission. More than 100 years after Tesla, the progress in modern semiconductor technology offer developers the possibility to realize highly efficient systems and have led to a revival of wireless energy transmission. The application ranges from the transmission of a few milliwatts in biomedical applications, over a few watts for the charging of mobile phones, to hundreds of kilowatts in the automotive sector. Depending on the used method, the possible transmission distances vary between a few centimeters up to thousands of kilometers. The physical basis of these technologies is the transmission of energy by electromagnetic waves. State-of-the-art systems use wavelengths ranging from radio waves to microwaves, to ultraviolet light. Current research focuses on optimizing transmission efficiency, increasing the possible transmission distance between transmitter and receiver, and improving spatial freedom of movement. This lecture gives an overview of the different approaches of wireless energy transmission and their physical background, the established industrial standards and the current state of research. In addition, the advantages and disadvantages of the individual methods are illustrated by selected commercial and scientific applications. (rössner) [de

  3. Bonneville Power Administration Transmission System Vegetation Management Program - Final Environmental Impact Statement

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2000-06-23

    Bonneville is responsible for maintaining a network of 24,000 kilometers (km) or 15,000 miles (mi.) of electric transmission lines and 350 substations in a region of diverse vegetation. This vegetation can interfere with electric power flow, pose safety problems for us and the public, and interfere with our ability to maintain these facilities. We need to (1) keep vegetation away from our electric facilities; (2) increase our program efficiency and consistency; (3) review herbicide use (under increased public scrutiny); and (4) maximize the range of tools we can use while minimizing environmental impact (Integrated Vegetation Management). This Final Environmental Impact Statement (FEIS) establishes Planning Steps for managing vegetation for specific projects (to be tiered to this Environmental Impact Statement (EIS)). In addition to No Action (current practice), alternatives are presented for Rights-of-way, Electric Yards, and Non-electric Facilities (landscaping, work yards). Four vegetation control methods are analyzed manual, mechanical, herbicide, and biological. Also evaluated are 23 herbicide active ingredients and 4 herbicide application techniques (spot, localized, broadcast, and aerial). For rights-of-way, we consider three sets of alternatives: alternative management approaches (time-driven or establishing low-growing plant communities); alternative method packages; and, if herbicides are in a methods package, alternative vegetation selections (noxious weeds, deciduous, or any vegetation). For electric yards, one herbicide-use alternative is considered. For non-electric facilities, two method package alternatives are considered. For rights-of-way, the environmentally preferred alternative(s) would use manual, mechanical, and biological control methods, as well as spot and localized herbicide applications for noxious and deciduous plant species; the BPA-preferred alternative(s) would add broadcast and aerial herbicide applications, and would use herbicides

  4. Harmonics in Offshore Wind Power Plants Employing Power Electronic Devices in the Transmission System

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm

    Introduction The trend in power generation is to partly replace conventional power plants with renewable energy sources. Offshore wind power has been selected to take up a significant proportion of the renewable energy production. The grid codes have been updated to accommodate the rising share...... of wind power. The onshore as well as offshore wind power plants (OWPPs) therefore have to meet the same stringent requirement as the conventional power plants. This can be accommodated by employment of flexible alternating current transmission system (FACTS) devices, such as the static compensator...... gives rise to a number of challenges to the wind power industry with regard to construction, installation as well as transmission of the generated energy. The STATCOM and the voltage-sourced converter high-voltage direct current (VSC-HVDC) are attractive solutions for grid connection of remotely located...

  5. Transmission Integration | Grid Modernization | NREL

    Science.gov (United States)

    Transmission Integration Transmission Integration The goal of NREL's transmission integration integration issues and provide data, analysis, and models to enable the electric power system to more and finding solutions to address them to enable transmission grid integration. Capabilities Power

  6. Compensated pulsed alternator

    International Nuclear Information System (INIS)

    Weldon, W.F.; Driga, M.D.; Woodson, H.H.

    1980-01-01

    This invention relates to an electromechanical energy converter with inertial energy storage. The device, a single phase, two or multi-pole alternator with stationary field coils, and a rotating armature is provided. The rotor itself may be of laminated steel for slower pulses or for faster pulses should be nonmagnetic and electrically nonconductive in order to allow rapid penetration of the field as the armature coil rotates. The armature coil comprises a plurality of power generating conductors mounted on the rotor. The alternator may also include a stationary or counterrotating compensating coil to increase the output voltage thereof and to reduce the internal impedance of the alternator at the moment of peak output. As the machine voltage rises sinusoidally, an external trigger switch is adapted to be closed at the appropriate time to create the desired output current from said alternator to an external load circuit, and as the output current passes through zero a self-commutating effect is provided to allow the switch to disconnect the generator from the external circuit

  7. Flexible AC transmission systems: the state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Edris, Abdel-Aty [Electric Power Research Inst., Palo Alto, CA (United States). Electric Systems Division

    1994-12-31

    Flexible AC transmission systems (FACTS) is a concept promoting the use of power electronic controllers to enhance the controllability and usable capacity of AC transmission. This paper presents the state of the art of FACTS and the status of the current projects for the application of the FACTS controllers in transmission systems. (author) 8 refs., 8 figs.

  8. Water-hydraulic power transmission for offshore wind farms

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin Laguna, A.; Kempenaar, A.S.

    2012-01-01

    The current state of the art of offshore wind turbine power transmission technology is expensive, heavy and maintenance intensive. The Delft Offshore Turbine project considers a radically new concept for power transmission in an offshore wind farm: using seawater as power transmission medium. For

  9. Energy alternatives

    International Nuclear Information System (INIS)

    1981-01-01

    English. A special committe of the Canadian House of Commons was established on 23 May 1980 to investigate the use of alternative energy sources such as 'gasohol', liquified coal, solar energy, methanol, wind and tidal power, biomass, and propane. In its final report, the committee envisions an energy system for Canada based on hydrogen and electricity, using solar and geothermal energy for low-grade heat. The committe was not able to say which method of generating electricty would dominate in the next century, although it recommends that fossil fuels should not be used. The fission process is not specifically discussed, but the outlook for fusion was investigated, and continued governmental support of fusion research is recommended. The report proposes some improvements in governmental energy organizations and programs

  10. Series Transmission Line Transformer

    Science.gov (United States)

    Buckles, Robert A.; Booth, Rex; Yen, Boris T.

    2004-06-29

    A series transmission line transformer is set forth which includes two or more of impedance matched sets of at least two transmissions lines such as shielded cables, connected in parallel at one end ans series at the other in a cascading fashion. The cables are wound about a magnetic core. The series transmission line transformer (STLT) which can provide for higher impedance ratios and bandwidths, which is scalable, and which is of simpler design and construction.

  11. Alternative RNA splicing and cancer

    Science.gov (United States)

    Liu, Sali; Cheng, Chonghui

    2015-01-01

    Alternative splicing of pre-messenger RNA (mRNA) is a fundamental mechanism by which a gene can give rise to multiple distinct mRNA transcripts, yielding protein isoforms with different, even opposing, functions. With the recognition that alternative splicing occurs in nearly all human genes, its relationship with cancer-associated pathways has emerged as a rapidly growing field. In this review, we summarize recent findings that have implicated the critical role of alternative splicing in cancer and discuss current understandings of the mechanisms underlying dysregulated alternative splicing in cancer cells. PMID:23765697

  12. Drivers of Tuberculosis Transmission.

    Science.gov (United States)

    Mathema, Barun; Andrews, Jason R; Cohen, Ted; Borgdorff, Martien W; Behr, Marcel; Glynn, Judith R; Rustomjee, Roxana; Silk, Benjamin J; Wood, Robin

    2017-11-03

    Measuring tuberculosis transmission is exceedingly difficult, given the remarkable variability in the timing of clinical disease after Mycobacterium tuberculosis infection; incident disease can result from either a recent (ie, weeks to months) or a remote (ie, several years to decades) infection event. Although we cannot identify with certainty the timing and location of tuberculosis transmission for individuals, approaches for estimating the individual probability of recent transmission and for estimating the fraction of tuberculosis cases due to recent transmission in populations have been developed. Data used to estimate the probable burden of recent transmission include tuberculosis case notifications in young children and trends in tuberculin skin test and interferon γ-release assays. More recently, M. tuberculosis whole-genome sequencing has been used to estimate population levels of recent transmission, identify the distribution of specific strains within communities, and decipher chains of transmission among culture-positive tuberculosis cases. The factors that drive the transmission of tuberculosis in communities depend on the burden of prevalent tuberculosis; the ways in which individuals live, work, and interact (eg, congregate settings); and the capacity of healthcare and public health systems to identify and effectively treat individuals with infectious forms of tuberculosis. Here we provide an overview of these factors, describe tools for measurement of ongoing transmission, and highlight knowledge gaps that must be addressed. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  13. The renewable alternative

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses renewable energy sources as an alternative to a fossil fuel based economy. The topics discussed in the chapter include the historic aspects and current status of use of renewable energy, status of the renewable energy industry, market barriers to renewable energy, research and development and commercialization of renewable energy, the environmental and social costs associated with renewable energy, valuing future costs and benefits of energy use, and the potential market of renewable energy

  14. Metamaterials critique and alternatives

    CERN Document Server

    Munk, Ben A

    2009-01-01

    A Convincing and Controversial Alternative Explanation of Metamaterials with a Negative Index of Refraction In a book that will generate both support and controversy, one of the world's foremost authorities on periodic structures addresses several of the current fashions in antenna design-most specifically, the popular subject of double negative metamaterials. Professor Munk provides a comprehensive theoretical electromagnetic investigation of the issues and concludes that many of the phenomena claimed by researchers may be impossible. While denying the existence of negative refractio

  15. Energy alternative

    International Nuclear Information System (INIS)

    Suarez Antola, R.

    2010-01-01

    The present work is about primary sources the conventional fossil fuels (petroleum, coal and natural gas) and not conventional (nuclear fuels), as well as the solar light that reaches the floor, the winds, the rivers, the oceanic currents including the seas, and the biomass, among others. In the present technological era the primary sources are used for the most part to transform their energy into electric power.

  16. Reflection and transmission of light at periodic layered metamaterial films

    Science.gov (United States)

    Paul, Thomas; Menzel, Christoph; Śmigaj, Wojciech; Rockstuhl, Carsten; Lalanne, Philippe; Lederer, Falk

    2011-09-01

    The appropriate description of light scattering (transmission/reflection) at a bulky artificial medium, consisting of a sequence of functional metamaterial and natural material films, represents a major challenge in current theoretical nano-optics. Because in many relevant cases, in particular, in the optical domain, a metamaterial must not be described by an effective permittivity and permeability the usual Fresnel formalism cannot be applied. A reliable alternative consists in using a Bloch mode formalism known, e.g., from the theory of photonic crystals. It permits to split this complex issue into two more elementary ones, namely the study of light propagation in an infinitely extended metamaterial and the analysis of light scattering at interfaces between adjacent meta and natural materials. The first problem is routinely solved by calculating the relevant Bloch modes and their dispersion relations. The second task is more involved and represents the subject of the present study. It consists in using the general Bloch mode orthogonality to derive rigorous expressions for the reflection and transmission coefficients at an interface between two three-dimensional absorptive periodic media for arbitrary incidence. A considerable simplification can be achieved if only the fundamental Bloch modes of both media govern the scattering properties at the interface. If this approximation is valid, which depends on the longitudinal metamaterial period, the periodic metamaterial may be termed homogeneous. Only in this case the disentanglement of the fundamental modes of both media can be performed and the reflection/transmission coefficients can be expressed in terms of two impedances, each depending solely on the properties of the fundamental mode of the respective medium. In order to complement the picture, we apply the present formalism to the quite general problem of reflection/transmission at a metamaterial film sandwiched between a dissimilar metamaterial. This

  17. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    2012-01-01

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  18. Cultural Transmission of Civicness

    DEFF Research Database (Denmark)

    Ljunge, Jan Martin

    This paper estimates the intergeneration transmission of civicness by studying second generation immigrants in 29 European countries with ancestry in 83 nations. There is significant transmission of civicness both on the mother’s and the father’s side. The estimates are quantitatively significant...

  19. Poverty and price transmission

    DEFF Research Database (Denmark)

    Elleby, Christian

    A key parameter determining the welfare impact from a world market shock is the transmission elasticity which measures the average domestic response to an international price change. Many studies have estimated price transmission elasticities for a large number of countries but the variation in t...

  20. Transmission market support system

    International Nuclear Information System (INIS)

    Reinschmidt, K.F.; Coles, B.C.

    1995-01-01

    An interactive, computer-based market support system has been developed for transmission access that is efficient, equitable, and fair to all parties concerned with electrical transmission: utilities, electric generators, owners of transmission networks, and wholesale purchasers of electrical power. Each participant transmits electronically to the computer system his proposed price schedule for buying, selling, or transmitting power for each future time period. The price for transmission on a single line in one direction can differ from the price in the other direction. The total quantity offered in the transmission bid represents the capacity of the line, and the flow on the line cannot exceed this value. The system automatically computes the prices that clear the market; that is, the price that each generator receives at each bus, the price that each transmission operator receives on each line, and the price that each customer pays at each bus. The computer system maximizes the benefits to all three classes while satisfying the electrical characteristics of the transmission system by means of load flow calculations. Customers never pay more than their bid prices (but may pay less), and generators and transmission operators never receive less than their bid prices (but may receive more). The price at each bus applies to all buyers and sellers at that bus: all buyers at the same bus pay the same price and all generators at a bus receive the same price

  1. Pricing transmission services

    International Nuclear Information System (INIS)

    Haaden, E.

    1995-01-01

    The price structure for transmission of electric power through the main lines in Sweden is analyzed. After deregulation of the electricity market, the main transmission lines are owned by a separate national company, with no interests from the power producers. Comparisons are made to ideal marginal price structures. 6 refs

  2. Eliminating Perinatal HIV Transmission

    Centers for Disease Control (CDC) Podcasts

    In this podcast, CDC’s Dr. Steve Nesheim discusses perinatal HIV transmission, including the importance of preventing HIV among women, preconception care, and timely HIV testing of the mother. Dr. Nesheim also introduces the revised curriculum Eliminating Perinatal HIV Transmission intended for faculty of OB/GYN and pediatric residents and nurse midwifery students.

  3. Planning Electric Transmission Lines: A Review of Recent Regional Transmission Plans

    Energy Technology Data Exchange (ETDEWEB)

    Eto, Joseph H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-04-13

    The first Quadrennial Energy Review (QER) recommends that the U.S. Department of Energy (DOE) conduct a national review of transmission plans and assess the barriers and incentives to their implementation. DOE tasked Lawrence Berkeley National Laboratory (LBNL) to prepare two reports to support the agency’s response to this recommendation. This report reviews regional transmission plans and regional transmission planning processes that have been directed by Federal Energy Regulatory Commission (FERC) Order Nos. 890 and 1000. We focus on the most recent regional transmission plans (those issued in 2015 and through approximately mid-year 2016) and current regional transmission planning processes. A companion report focuses on non-plan-related factors that affect transmission projects.

  4. Microwave energy transmission

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Hiroshi [Kyoto Univ. (Japan)

    1989-03-05

    Laying stress on the technological problems and effect on the environment of microwave energy transmission, recent scientific and engineering problems and related subjects are described. Because no fuel is required for the solar power generation, the power generation system can not be considered as an expensive one when the unit cost of energy is taken into consideration. Some of the important technological problems in the microwave energy transmission are accurate microwave beam control technology to receiving stations and improvement in the efficiency of transmission system. Microwave energy beam has effects on living bodies, communication, and plasma atmosphere of the earth. Microwave energy transmission using a space flyer unit is scheduled. Its objective is the development of microwave wireless transmission technology and the study of the correlation between high power microwave and ionosphere plasma. Experiments on such a small scale application as a microwave driven space ship to bring results seem also important. 12 refs., 13 figs.

  5. Harmonics in transmission power systems

    DEFF Research Database (Denmark)

    Wiechowski, Wojciech Tomasz

    . The comparison shows that results obtained used both types of the cores are the same, so it is concluded that both cores can be used for harmonic measurements. Low-inductance resistors are introduced in the secondary circuits, in series with the metering and protective relaying. On those resistors, the harmonic......Some time ago, Energinet.dk, the Transmission System Operator of the 150 kV and 400 kV transmission network in Denmark, had experienced operational malfunctions of some of the measuring and protection equipment. Also an overloading of a harmonic filter has been reported, and therefore, a need...... end only so the ground is not used as a return path. A way to reduce the capacitive coupling is to provide shielding. Harmonic currents are measured using the conventional inductive voltage transformers. Both protective and metering cores were compared if they could be used for harmonic measurements...

  6. Transmission of Influenza A Viruses

    Science.gov (United States)

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  7. Transmission : roadway to a competitive electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Thon, S. [AltaLink L.P., AB (Canada)

    2002-07-01

    Having a variety of suppliers, marketers and retailers is the key to developing a successful electricity market which is more competitive on pricing, with less price volatility, more innovative customer products and higher levels of customer services. Some areas of Alberta are developing their own power markets with limited capacity to interact. These include Pincher Creek, Empress, Calgary, Edmonton, and Fort McMurray. It was noted that increasing transmission capacity is the key to ensuring a bigger and more competitive electricity market. Transmission constraints only encourage a small number of suppliers to control the market. The current cost of transmission capacity accounts for less than 5 per cent of an average residential customer's bill, but it plays a major role in providing more choice to competitive electricity suppliers. Developing more transmission capacity will create an even more competitive market that benefits both consumers and suppliers. Prices in Alberta have been very volatile in the past couple of years because of supply and demand issues, and there is a need to increase market liquidity. Alberta's Transmission Administrator is looking to expand the transmission network to alleviate constraints and to lower the cost of power generation, regardless of location. These expansions are not expected to affect customers' bills by more than 2 to 3 per cent. Such transmission concerns are being felt all over North America. The Federal Energy Regulatory Commission (FERC) in the United States also recognizes the link between transmission and creating a competitive electricity market.

  8. Maritime wideband communication networks video transmission scheduling

    CERN Document Server

    Yang, Tingting

    2014-01-01

    This Springer Brief covers emerging maritime wideband communication networks and how they facilitate applications such as maritime distress, urgency, safety and general communications. It provides valuable insight on the data transmission scheduling and protocol design for the maritime wideband network. This brief begins with an introduction to maritime wideband communication networks including the architecture, framework, operations and a comprehensive survey on current developments. The second part of the brief presents the resource allocation and scheduling for video packet transmission wit

  9. Money and the Transmission of Monetary Policy

    OpenAIRE

    Seth Carpenter; Selva Demiralp

    2009-01-01

    The transmission mechanism of monetary policy has received extensive treatment in the macroeconomic literature. Most models currently used for macroeconomic analysis exclude money or else model money demand as entirely endogenous. Nevertheless, academic research and many textbooks continue to use the money multiplier concept in discussions of money. We explore the institutional structure of the transmission mechanism beginning with open market operations through to money and loans to document...

  10. Does more international transmission capacity increase competition in the Belgian electricity market?

    NARCIS (Netherlands)

    Kupper, G.; Delarue, E.; Delvaux, B.; Meeus, L.; Bekaert, D.; Willems, Bert; Proost, S.; D'haeseleer, W.; Deketelaere, K.; Belmans, R.

    2009-01-01

    From a national market perspective, taking transmission capacity into account reduces current concentration measures, although they remain fairly high even after substantial capacity increases. From an international perspective, a more efficient use of current transmission capacity by coupling

  11. Airborne or Fomite Transmission for Norovirus? A Case Study Revisited.

    Science.gov (United States)

    Xiao, Shenglan; Tang, Julian W; Li, Yuguo

    2017-12-14

    Norovirus infection, a highly prevalent condition associated with a high rate of morbidity, comprises a significant health issue. Although norovirus transmission mainly occurs via the fecal-oral and vomit-oral routes, airborne transmission has been proposed in recent decades. This paper re-examines a previously described norovirus outbreak in a hotel restaurant wherein airborne transmission was originally inferred. Specifically, the original evidence that suggested airborne transmission was re-analyzed by exploring an alternative hypothesis: could this outbreak instead have occurred via fomite transmission? This re-analysis was based on whether fomite transmission could have yielded similar attack rate distribution patterns. Seven representative serving pathways used by waiters were considered, and the infection risk distributions of the alternative fomite transmission routes were predicted using a multi-agent model. These distributions were compared to the reported attack rate distribution in the original study using a least square methods approach. The results show that with some reasonable assumptions of human behavior patterns and parameter values, the attack rate distribution corresponded well with that of the infection risk via the fomite route. This finding offers an alternative interpretation of the transmission routes that underlay this particular norovirus outbreak and an important consideration in the development of infection control guidelines and the investigation of similar norovirus outbreaks in future.

  12. The paradox of transmission system value

    International Nuclear Information System (INIS)

    Haddad, S.Z.; Feldman, R.D.; Charnetzki, P.

    1995-01-01

    The central importance of utility strategic planning with respect to transmission systems has developed as a result of the passage of the Energy Policy Act and the rapid emergence of the era of open grid access. As a consequence, utilities have had to redefine transmission as being more than a cost center managed with reliability as the principal focus and regulated on a rate of return basis. Transmission must now be managed with a view to protection of customers, where possible, and to revenue maximization, both through pricing strategy and through operations. This shift has been compounded by the pressures being thrust upon utilities by regulators or being fomented by competitors to unbundle transmission and distribution from generation. This paper explores how the value of the transmission system can be viewed from the vantage points of different organizations (utilities, regulators, customers, independent generators, etc.). The paper addresses the uncertain and apparently paradoxical nature of transmission system value as it will be impacted by the possible alternative future structures of the electric power industry. Lastly, this paper suggests the strategic possibilities for utilities that this uncertainty presents

  13. Cost characteristics of transmission

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    FERC regulation of transmission is predicated, at least in part, on a belief that, in the absence of regulation, some utilities would be able to exercise monopoly power and the ability to extract monopoly profits. This monopoly power follows from the view that transmission facilities inevitably are a natural monopoly for both economic and social/regulatory reasons. In the first part of this section the authors present the argument that transmission is a natural monopoly. They then consider the impact of this on regulation and the problems that that view creates

  14. Understanding Ebola Virus Transmission

    Directory of Open Access Journals (Sweden)

    Seth Judson

    2015-02-01

    Full Text Available An unprecedented number of Ebola virus infections among healthcare workers and patients have raised questions about our understanding of Ebola virus transmission. Here, we explore different routes of Ebola virus transmission between people, summarizing the known epidemiological and experimental data. From this data, we expose important gaps in Ebola virus research pertinent to outbreak situations. We further propose experiments and methods of data collection that will enable scientists to fill these voids in our knowledge about the transmission of Ebola virus.

  15. Transmission policy in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Joskow, P.L. [Massachusetts Institute of Technology, Cambridge, MA (United States). Department of Economics

    2005-06-01

    This paper provides an overview of the development of electric power transmission access, pricing and investment policies in the US over the last 15 years and evaluates the current state of those policies. Pre-liberalization transmission access and pricing policies are reviewed first since more recent policies have evolved from them. FERC's efforts to ensure that transmission owning utilities provide non-discriminatory access and pricing to wholesale transmission customers, culminating in Order 888 and 889 are discussed. These rules did not respond to problems created by a highly balkanized transmission system and only partially responded to problems caused by common ownership and operation of transmission networks with generating and marketing businesses in the same regions. These problems motivated FERC to seek to create Regional Transmission Organizations (RTO) meeting a long list of criteria related to governance, network operations, transmission pricing and investment as reflected in Order 2000. The slow pace of 'voluntary' reform following Order 2000 led FERC to issue a proposed Standard Market Design Rule (SMD) which provided more detailed prescriptions for wholesale market design, network operations, regional planning, resource adequacy, and transmission investment. The SMD rule confronted enormous resistance from groups of utilities and states that had not embraced an electricity sector liberalization agenda. However, many of the provisions of the SMD are being implemented by the RTOs and ISOs in the Northeast and Midwest. PJM's market rules and transmission pricing, planning and investment policies are reviewed as an articulation of FERC's RTO and SMD visions. (author)

  16. Transmission issues in Alberta

    International Nuclear Information System (INIS)

    Levson, D.

    2002-01-01

    This paper outlined the major issues and concerns facing users of the transmission system in Alberta. They include congestion management issues that make investors uncertain about power generation. It is necessary to know the difference between which transmission price signals will be faced by low cost cogeneration at Fort McMurray and Cold Lake coal-fired generation near Edmonton compared to combined cycle gas generation near Calgary. Import and export policy tariffs are another concern. Most new generation opportunities in Alberta require access to export markets, but transmission facilities for export need policy support and appropriate tariffs. It was noted that the past actions of Alberta's Transmission Administrator and balancing pool may be distorting market signals for ancillary service markets, and that loss studies and calculations need upgrading

  17. Kansas Electric Transmission Lines

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set is a digital representation of the EletcircTransmission lines for the State of Kansas as maintained by the Kansas Corporation Commission. Data is...

  18. ECRH transmission system

    International Nuclear Information System (INIS)

    Tancredi, J.

    1983-01-01

    Hughes, Electron Dynamics Division is developing gyrotrons for ECRH requirements. In the development program, techniques have been evolved for transmission system components. These techniques include over-moded waveguide tapers, high average power windows, and rf water loads for testing

  19. Electric Power Transmission Lines

    Data.gov (United States)

    Department of Homeland Security — Transmission Lines are the system of structures, wires, insulators and associated hardware that carry electric energy from one point to another in an electric power...

  20. Integrated Transmission and Distribution Control

    Energy Technology Data Exchange (ETDEWEB)

    Kalsi, Karanjit [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fuller, Jason C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tuffner, Francis K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lian, Jianming [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhang, Wei [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Marinovici, Laurentiu D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fisher, Andrew R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chassin, Forrest S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hauer, Matthew L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-01-01

    Distributed, generation, demand response, distributed storage, smart appliances, electric vehicles and renewable energy resources are expected to play a key part in the transformation of the American power system. Control, coordination and compensation of these smart grid assets are inherently interlinked. Advanced control strategies to warrant large-scale penetration of distributed smart grid assets do not currently exist. While many of the smart grid technologies proposed involve assets being deployed at the distribution level, most of the significant benefits accrue at the transmission level. The development of advanced smart grid simulation tools, such as GridLAB-D, has led to a dramatic improvement in the models of smart grid assets available for design and evaluation of smart grid technology. However, one of the main challenges to quantifying the benefits of smart grid assets at the transmission level is the lack of tools and framework for integrating transmission and distribution technologies into a single simulation environment. Furthermore, given the size and complexity of the distribution system, it is crucial to be able to represent the behavior of distributed smart grid assets using reduced-order controllable models and to analyze their impacts on the bulk power system in terms of stability and reliability.