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Sample records for provoke dynamic electric

  1. Provoked vestibulodynia: current perspectives

    OpenAIRE

    Henzell,Helen; Berzins,Karen; Langford,Jennifer

    2017-01-01

    Helen Henzell,1,2 Karen Berzins,1,3 Jennifer P Langford4 1Melbourne Sexual Health Centre, Carlton, 2Action Centre, Family Planning Victoria, Melbourne, 3Dermatology/Vulval Conditions Clinic, Mercy Hospital for Women, Heidelberg, 4Clifton Hill Physiotherapy, Clifton Hill, VIC, Australia Abstract: Provoked vestibulodynia (PVD) refers to vulvar pain of at least 3 months duration, localized to the vestibule, provoked by touch and sexual activity and occurring in the absence of a clear identifia...

  2. Dynamics of electricity market correlations

    Science.gov (United States)

    Alvarez-Ramirez, J.; Escarela-Perez, R.; Espinosa-Perez, G.; Urrea, R.

    2009-06-01

    Electricity market participants rely on demand and price forecasts to decide their bidding strategies, allocate assets, negotiate bilateral contracts, hedge risks, and plan facility investments. However, forecasting is hampered by the non-linear and stochastic nature of price time series. Diverse modeling strategies, from neural networks to traditional transfer functions, have been explored. These approaches are based on the assumption that price series contain correlations that can be exploited for model-based prediction purposes. While many works have been devoted to the demand and price modeling, a limited number of reports on the nature and dynamics of electricity market correlations are available. This paper uses detrended fluctuation analysis to study correlations in the demand and price time series and takes the Australian market as a case study. The results show the existence of correlations in both demand and prices over three orders of magnitude in time ranging from hours to months. However, the Hurst exponent is not constant over time, and its time evolution was computed over a subsample moving window of 250 observations. The computations, also made for two Canadian markets, show that the correlations present important fluctuations over a seasonal one-year cycle. Interestingly, non-linearities (measured in terms of a multifractality index) and reduced price predictability are found for the June-July periods, while the converse behavior is displayed during the December-January period. In terms of forecasting models, our results suggest that non-linear recursive models should be considered for accurate day-ahead price estimation. On the other hand, linear models seem to suffice for demand forecasting purposes.

  3. Management of provoked seizure

    Directory of Open Access Journals (Sweden)

    Misra Usha

    2011-01-01

    Full Text Available A provoked seizure may be due to structural damage (resulting from traumatic brain injury, brain tumor, stroke, tuberculosis, or neurocysticercosis or due to metabolic abnormalities (such as alcohol withdrawal and renal or hepatic failure. This article is a part of the Guidelines for Epilepsy in India. This article reviews the problem of provoked seizure and its management and also provides recommendations based on currently available information. Seizure provoked by metabolic disturbances requires correction of the triggering factors. Benzodiazepines are recommended for treatment of seizure due to alcohol withdrawal; gabapentin for seizure seen in porphyria; and antiepileptic drugs (AED, that are not inducer of hepatic enzymes, in the seizures seen in hepatic dysfunction. In severe traumatic brain injury, with or without seizure, phenytoin (PHT may be given for 7 days. In ischemic or hemorrhagic stroke one may individualize the AED therapy. In cerebral venous sinus thrombosis (CVST, AED may be prescribed if there is seizure or computed tomographic (CT abnormalities or focal weakness; the treatment, in these cases, has to be continued for 1 year. Prophylactic AED is not recommended in cases of brain tumor and neurosurgical procedures and if patient is on an AED it can be stopped after 1 week.

  4. Management of provoked seizure.

    Science.gov (United States)

    Misra, Usha Kant; Kalita, Jayantee

    2011-01-01

    A provoked seizure may be due to structural damage (resulting from traumatic brain injury, brain tumor, stroke, tuberculosis, or neurocysticercosis) or due to metabolic abnormalities (such as alcohol withdrawal and renal or hepatic failure). This article is a part of the Guidelines for Epilepsy in India. This article reviews the problem of provoked seizure and its management and also provides recommendations based on currently available information. Seizure provoked by metabolic disturbances requires correction of the triggering factors. Benzodiazepines are recommended for treatment of seizure due to alcohol withdrawal; gabapentin for seizure seen in porphyria; and antiepileptic drugs (AED), that are not inducer of hepatic enzymes, in the seizures seen in hepatic dysfunction. In severe traumatic brain injury, with or without seizure, phenytoin (PHT) may be given for 7 days. In ischemic or hemorrhagic stroke one may individualize the AED therapy. In cerebral venous sinus thrombosis (CVST), AED may be prescribed if there is seizure or computed tomographic (CT) abnormalities or focal weakness; the treatment, in these cases, has to be continued for 1 year. Prophylactic AED is not recommended in cases of brain tumor and neurosurgical procedures and if patient is on an AED it can be stopped after 1 week.

  5. Imaging electric field dynamics with graphene optoelectronics.

    Science.gov (United States)

    Horng, Jason; Balch, Halleh B; McGuire, Allister F; Tsai, Hsin-Zon; Forrester, Patrick R; Crommie, Michael F; Cui, Bianxiao; Wang, Feng

    2016-12-16

    The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts, a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena.

  6. Provoked vestibulodynia: current perspectives.

    Science.gov (United States)

    Henzell, Helen; Berzins, Karen; Langford, Jennifer P

    2017-01-01

    Provoked vestibulodynia (PVD) refers to vulvar pain of at least 3 months duration, localized to the vestibule, provoked by touch and sexual activity and occurring in the absence of a clear identifiable cause. The clinical spectrum ranges from mild with distressing discomfort through to severe and disabling pain. Current understanding is that PVD is one of many chronic pain conditions characterized by sensitization of peripheral and central nociceptive pathways, with pain arising due to dysfunctional neuronal activity in the absence of painful stimuli. Pathophysiology is not well understood but is likely a complex interplay of environmental, genetic, psychological and immune factors. Care is multidisciplinary and follows general principles of chronic pain management with the addition of specific therapy tailored to address pelvic floor overactivity, and sexual and relationship difficulties. More recently, the therapeutic use of placebo is gaining traction in chronic pain research and is a very promising adjunctive therapy. The majority of women with PVD are managed outside of tertiary clinic settings, and care depends on availability and affordability of specialized services; however, much can be done by the primary health provider. PVD is common, and highly treatable, especially with early intervention, but unfortunately, many clinicians are unaware of this condition, and the biggest hurdle for women accessing treatment is obtaining a diagnosis. With treatment, most women can expect significant improvement, often with fairly simple interventions, although some women will benefit from referral to specialized centers. The aims of this article are twofold: firstly, to summarize current literature concerning PVD pathophysiology and management; secondly, to provide a framework for clinicians unfamiliar with vulvar medicine to understand and manage PVD.

  7. Provoked vestibulodynia: current perspectives

    Directory of Open Access Journals (Sweden)

    Henzell H

    2017-09-01

    Full Text Available Helen Henzell,1,2 Karen Berzins,1,3 Jennifer P Langford4 1Melbourne Sexual Health Centre, Carlton, 2Action Centre, Family Planning Victoria, Melbourne, 3Dermatology/Vulval Conditions Clinic, Mercy Hospital for Women, Heidelberg, 4Clifton Hill Physiotherapy, Clifton Hill, VIC, Australia Abstract: Provoked vestibulodynia (PVD refers to vulvar pain of at least 3 months duration, localized to the vestibule, provoked by touch and sexual activity and occurring in the absence of a clear identifiable cause. The clinical spectrum ranges from mild with distressing discomfort through to severe and disabling pain. Current understanding is that PVD is one of many chronic pain conditions characterized by sensitization of peripheral and central nociceptive pathways, with pain arising due to dysfunctional neuronal activity in the absence of painful stimuli. Pathophysiology is not well understood but is likely a complex interplay of environmental, genetic, psychological and immune factors. Care is multidisciplinary and follows general principles of chronic pain management with the addition of specific therapy tailored to address pelvic floor overactivity, and sexual and relationship difficulties. More recently, the therapeutic use of placebo is gaining traction in chronic pain research and is a very promising adjunctive therapy. The majority of women with PVD are managed outside of tertiary clinic settings, and care depends on availability and affordability of specialized services; however, much can be done by the primary health provider. PVD is common, and highly treatable, especially with early intervention, but unfortunately, many clinicians are unaware of this condition, and the biggest hurdle for women accessing treatment is obtaining a diagnosis. With treatment, most women can expect significant improvement, often with fairly simple interventions, although some women will benefit from referral to specialized centers. The aims of this article are twofold

  8. Provoked vestibulodynia: current perspectives

    Science.gov (United States)

    Henzell, Helen; Berzins, Karen; Langford, Jennifer P

    2017-01-01

    Provoked vestibulodynia (PVD) refers to vulvar pain of at least 3 months duration, localized to the vestibule, provoked by touch and sexual activity and occurring in the absence of a clear identifiable cause. The clinical spectrum ranges from mild with distressing discomfort through to severe and disabling pain. Current understanding is that PVD is one of many chronic pain conditions characterized by sensitization of peripheral and central nociceptive pathways, with pain arising due to dysfunctional neuronal activity in the absence of painful stimuli. Pathophysiology is not well understood but is likely a complex interplay of environmental, genetic, psychological and immune factors. Care is multidisciplinary and follows general principles of chronic pain management with the addition of specific therapy tailored to address pelvic floor overactivity, and sexual and relationship difficulties. More recently, the therapeutic use of placebo is gaining traction in chronic pain research and is a very promising adjunctive therapy. The majority of women with PVD are managed outside of tertiary clinic settings, and care depends on availability and affordability of specialized services; however, much can be done by the primary health provider. PVD is common, and highly treatable, especially with early intervention, but unfortunately, many clinicians are unaware of this condition, and the biggest hurdle for women accessing treatment is obtaining a diagnosis. With treatment, most women can expect significant improvement, often with fairly simple interventions, although some women will benefit from referral to specialized centers. The aims of this article are twofold: firstly, to summarize current literature concerning PVD pathophysiology and management; secondly, to provide a framework for clinicians unfamiliar with vulvar medicine to understand and manage PVD. PMID:28979166

  9. Indonesia’s Electricity Demand Dynamic Modelling

    Science.gov (United States)

    Sulistio, J.; Wirabhuana, A.; Wiratama, M. G.

    2017-06-01

    Electricity Systems modelling is one of the emerging area in the Global Energy policy studies recently. System Dynamics approach and Computer Simulation has become one the common methods used in energy systems planning and evaluation in many conditions. On the other hand, Indonesia experiencing several major issues in Electricity system such as fossil fuel domination, demand - supply imbalances, distribution inefficiency, and bio-devastation. This paper aims to explain the development of System Dynamics modelling approaches and computer simulation techniques in representing and predicting electricity demand in Indonesia. In addition, this paper also described the typical characteristics and relationship of commercial business sector, industrial sector, and family / domestic sector as electricity subsystems in Indonesia. Moreover, it will be also present direct structure, behavioural, and statistical test as model validation approach and ended by conclusions.

  10. Wave dynamics of electric explosion in solids

    Science.gov (United States)

    Burkin, V. V.; Kuznetsova, N. S.; Lopatin, V. V.

    2009-05-01

    A mathematical model of an electric explosion is developed that consistently describes the expansion of the explosion channel with regard to the parameters of the discharge circuit of a high-voltage pulse generator, radiation, and propagation of stress waves in a solid. The dynamics of conversion of the stored energy to a wave and the formation of mechanical stresses due to electric explosion in a solid immersed in a liquid are considered. In the context of electro-discharge destruction of hard materials, the resulting stress field and the relationship between the discharge circuit parameters and characteristics of the wave are analyzed and the most efficient discharge modes are determined.

  11. Molecular dynamics in high electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Apostol, M., E-mail: apoma@theory.nipne.ro; Cune, L.C.

    2016-06-15

    Highlights: • New method for rotation molecular spectra in high electric fields. • Parametric resonances – new features in spectra. • New elementary excitations in polar solids from dipolar interaction (“dipolons”). • Discussion about a possible origin of the ferroelectricity from dipolar interactions. - Abstract: Molecular rotation spectra, generated by the coupling of the molecular electric-dipole moments to an external time-dependent electric field, are discussed in a few particular conditions which can be of some experimental interest. First, the spherical-pendulum molecular model is reviewed, with the aim of introducing an approximate method which consists in the separation of the azimuthal and zenithal motions. Second, rotation spectra are considered in the presence of a static electric field. Two particular cases are analyzed, corresponding to strong and weak fields. In both cases the classical motion of the dipoles consists of rotations and vibrations about equilibrium positions; this motion may exhibit parametric resonances. For strong fields a large macroscopic electric polarization may appear. This situation may be relevant for polar matter (like pyroelectrics, ferroelectrics), or for heavy impurities embedded in a polar solid. The dipolar interaction is analyzed in polar condensed matter, where it is shown that new polarization modes appear for a spontaneous macroscopic electric polarization (these modes are tentatively called “dipolons”); one of the polarization modes is related to parametric resonances. The extension of these considerations to magnetic dipoles is briefly discussed. The treatment is extended to strong electric fields which oscillate with a high frequency, as those provided by high-power lasers. It is shown that the effect of such fields on molecular dynamics is governed by a much weaker, effective, renormalized, static electric field.

  12. Managing electricity demand through dynamic pricing

    Science.gov (United States)

    Peddie, Robert A.; Bulleit, Douglas A.

    1985-11-01

    As electrical energy cannot be stored in large quantities with current technology, the energy balance of the electricity supply system has to be maintained continually by adjustments in supply to meet an unrestricted customer demand. Electricity over the projected peak tends to be very expensive, so utilities have sought to restrict demand during such periods to improve internal economic efficiency. The techniques used can be shown to be inefficient and disruptive if widely applied. Due to the way the utility and the regulators have homogenized costs, rate structures provide the customer no useful cost message as motivation to economically control utilization. Advances in microelectronics and communications remove these restrictions by allowing the customer to be informed continually of the cost of a kiloWatt hour (kWh) at the time of use. For the first time, the ensuing control of demand by the customer enables efficient utilization and simplifies the dynamic control of the electric system. This paper describes the method of formulating dynamic prices, the main elements and examples of the system, and how it can be introduced. The enumerated benefits show that greater customer satisfaction and improved economic management of the nation's resources and the utility's assets would result.

  13. Electric power - Photovoltaic or solar dynamic?

    Science.gov (United States)

    Thomas, R. L.; Hallinan, G. J.; Hieatt, J. L.

    1985-01-01

    The design of the power system for supplying the Space Station with insolation-generated electricity is the main Phase B task at NASA-Lewis Center. The advantages and limitations of two types of power systems, the photovoltaic arrays (PV) and the solar dynamic system (SD), are discussed from the points of view of cost, overall systems integration, and growth. Subsystems of each of these options are described, and a sketch of a projected SD system is shown. The PV technology is well developed and proven, but its low efficiency calls for solar arrays of large areas, which affect station dynamics, control, and drag compensation. The SD systems would be less costly to operate than VP, and are more efficient, needing less deployed area. The major drawback of the SD is its infancy. The conservative and forgiving designs for some of its components must still be created and tested, and the development risks assessed.

  14. Holographic equilibration under external dynamical electric field

    Directory of Open Access Journals (Sweden)

    M. Ali-Akbari

    2017-10-01

    Full Text Available The holographic equilibration of a far-from-equilibrium strongly coupled gauge theory is investigated. In particular, the dynamics of a probe D7-brane in an AdS-Vaidya background is studied in the presence of an external time-dependent electric field. Defining the equilibration times teqc and teqj, at which condensation and current relax to their final equilibrated values, receptively, the smallness of transition time kM or kE is enough to observe a universal behaviour for re-scaled equilibration times kMkE(teqc−2 and kMkE(teqj−2. kM(kE is the time interval in which the temperature (electric field increases from zero to finite value. Moreover, regardless of the values for kM and kE, teqc/teqj also behaves universally for large enough value of the ratio of the final electric field to final temperature. Then a simple discussion of the static case reveals that teqc≤teqj. For an out-of-equilibrium process, our numerical results show that, apart from the cases for which kE is small, the static time-ordering, that is teqc≤teqj, persists.

  15. The Dynamics of Cardiac Electrical Instability.

    Science.gov (United States)

    Kaplan, Daniel Theodore

    This thesis examines the susceptibility of the heart to ventricular fibrillation from the point of view of nonlinear dynamical systems theory. Earlier work has established that susceptibility to fibrillation may be marked by an alternation from beat to beat in the shape of the ECG. This, as well as modeling of cardiac electrical conduction, led to speculation that fibrillation might be an instance of deterministic chaos, and that one of the theoretical routes to chaos--a cascade of period-doublings --might be followed. I study the possibility that fibrillation is deterministic chaos by the use of dimensionality calculations: the results suggest that there is not a low-dimensional dynamical system attractor underlying fibrillation. Both fibrillatory ECG's and models suggest that fibrillation may be a quasistationary transient. To search for evidence of high-order period-doublings, recordings from hypothermic dog and guinea pig hearts are studied using a variety of techniques based on state-space representations of the signals. As has been previously reported, alternation (period 2) is strongly associated with susceptibility to fibrillation. There is also some evidence of a 2^{nd} period -doubling (period 4) appearing in extremely hypothemic or rapidly paced hearts. A simple finite-element computer model of cardiac conduction is used to illustrate one possible mechanism of long periodicities (e.g. periods 2 and 4) in hearts. It is shown that incorporating a dependence of refractory period on stimulation rate permits the appearance in the model of the long periodicities observed in real data in a way which is independent of the geometry of the finite -element lattice used in the model. Furthermore, inclusion of refractory dynamics which allow individual cells to alternate disrupts the appearance of long periodicities and increases susceptibility to fibrillation.

  16. Dynamics and control of electrical drives

    Energy Technology Data Exchange (ETDEWEB)

    Wach, Piotr [Politechnika Opolska, Opole (Poland). Inst. of Electromechanical Systems and Applied Informatics

    2011-07-01

    Dynamics is a science concerned with movement and changes. In the most general approach it relates to life processes as well as behavior in nature in rest. It governs small particles, technical objects, conversion of matter and materials but also concerns people, groups of people in their individual and, in particular, social dimension. In dynamics we always have to do with causes or stimuli for motion, the rules of reaction or behavior and its result in the form of trajectory of changes. This book is devoted to dynamics of a wide class of specific but very important objects such as electromechanical systems. This is a very rigorous discipline and has a long tradition, as its theoretical bases were formulated in the first half of the XIX century by d' Alembert, Lagrange, Hamilton, Maxwell and other prominent scientists, but their crucial results were based on previous pioneering research of others such as Copernicus, Galileo, Newton..This book in its theoretical foundations is based on the principle of least action which governs classical as well as relativistic mechanics and electromagnetism and leads to Lagrange's equations which are applied in the book as universal method to construct equations of motion of electromechanical systems. It gives common and coherent grounds to formulate mathematical models for all lumped parameters' electromechanical systems, which are vital in our contemporary industry and civilized everyday life. From these remarks it seems that the book is general and theoretical but in fact it is a very practical one concerning modern electrical drives in a broad sense, including electromechanical energy conversion, induction motor drives, brushless DC drives with a permanent magnet excitation and switched reluctance machines (SRM). And of course their control, which means shaping of their trajectories of motion using modern tools, their designed autonomy in keeping a track according to our programmed expectations. The problems

  17. Hurst analysis of electricity price dynamics

    OpenAIRE

    Rafal Weron; Beata Przybylowicz

    2000-01-01

    The price of electricity is extremely volatile, because electric power cannot be economically stored, end user demand is largely weather dependent, and the reliability of the grid is paramount. However, underlying the process of price returns is a strong mean-reverting mechanism. We study this feature of electricity returns by means of Hurst R/S analysis.

  18. We want to be provoked

    DEFF Research Database (Denmark)

    Holmgren, Steen

    2001-01-01

    are often considered negative. But new views or knowledge are often provocative. To my opinion this is a good and needed provocation. For-given-taken professional values need to be questioned: as well as the usual roles of residents and professionals in the ongoing regeneration projects. My contribution......The title is a quotation from one of the meetings between residents and professionals during the Holmbladsgade regeneration process. During a discussion of future projects somebody asked what the residents expected from the professionals. We want to be provoked a resident answered. Provocations...

  19. Electric Potential and Electric Field Imaging with Dynamic Applications & Extensions

    Science.gov (United States)

    Generazio, Ed

    2017-01-01

    The technology and methods for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field made be used for volumes to be inspected with EFI. The baseline sensor technology (e-Sensor) and its construction, optional electric field generation (quasi-static generator), and current e- Sensor enhancements (ephemeral e-Sensor) are discussed. Critical design elements of current linear and real-time two-dimensional (2D) measurement systems are highlighted, and the development of a three dimensional (3D) EFI system is presented. Demonstrations for structural, electronic, human, and memory applications are shown. Recent work demonstrates that phonons may be used to create and annihilate electric dipoles within structures. Phonon induced dipoles are ephemeral and their polarization, strength, and location may be quantitatively characterized by EFI providing a new subsurface Phonon-EFI imaging technology. Results from real-time imaging of combustion and ion flow, and their measurement complications, will be discussed. Extensions to environment, Space and subterranean applications will be presented, and initial results for quantitative characterizing material properties are shown. A wearable EFI system has been developed by using fundamental EFI concepts. These new EFI capabilities are demonstrated to characterize electric charge distribution creating a new field of study embracing areas of interest including electrostatic discharge (ESD) mitigation, manufacturing quality control, crime scene forensics, design and materials selection for advanced sensors, combustion science, on-orbit space potential, container inspection, remote characterization of electronic circuits and level of activation, dielectric morphology of

  20. Handbook of electrical power system dynamics modeling, stability, and control

    CERN Document Server

    Eremia, Mircea

    2013-01-01

    Complete guidance for understanding electrical power system dynamics and blackouts This handbook offers a comprehensive and up-to-date treatment of power system dynamics. Addressing the full range of topics, from the fundamentals to the latest technologies in modeling, stability, and control, Handbook of Electrical Power System Dynamics provides engineers with hands-on guidance for understanding the phenomena leading to blackouts so they can design the most appropriate solutions for a cost-effective and reliable operation. Focusing on system dynamics, the book details

  1. New electrical stimulation techniques in dynamic myopasty

    NARCIS (Netherlands)

    Zonnevylle, Erik Dirk Hendrik

    2002-01-01

    It has become common practice in reconstructive surgery to transpose or transplant a variety of autologous tissues to fill defects at a recipient site. Using muscle tissue, it becomes possible to dynamically assist or replace an impaired or lost function. For these procedures the term ‘dynamic

  2. The Electrical and Dynamical Properties of Biomembranes

    DEFF Research Database (Denmark)

    Mosgaard, Lars Dalskov

    Biological membranes in living organisms play the fundamental role of acting as boundaries and facilitate compartmentalization. From a structural perspective they are essentially constituted by an amphiphilic lipid membrane in which sugars, peptides and proteins are incorporated. These quasi-2...... of the coupling between the membrane and the electrical eld within a universal thermodynamic framework. Within this framework, known electrical phenomena associated with lipid membranes such as o set voltage, electrostriction, piezoelectricity and exoelectricity can be captured and viewed as special cases...... into account the coupling between thermodynamical uctuations and the available heat reservoir. The next step is to combine the knowledge on lipid membranes subjected to an electrical eld with the knowledge on their relaxation behavior and use our understanding to attempt to re-evaluate the results of common...

  3. Risk factors associated with provoked pulmonary embolism.

    Science.gov (United States)

    Gjonbrataj, Endri; Kim, Ji Na; Gjonbrataj, Juarda; Jung, Hye In; Kim, Hyun Jung; Choi, Won-Il

    2017-01-01

    This study aimed to investigate the risk factors associated with provoked pulmonary embolism (PE). This retrospective cohort study included 237 patients with PE. Patients that had transient risk factors at diagnosis were classified as having provoked PE, with the remaining patients being classified as having unprovoked PE. The baseline clinical characteristics and factors associated with coagulation were compared. We evaluated the risk factors associated with provoked PE. Of the 237 PE patients, 73 (30.8%) had provoked PE. The rate of respiratory failure and infection, as well as the disseminated intravascular coagulation score and ratio of right ventricular diameter to left ventricular diameter were significantly higher in patients with provoked PE than in those with unprovoked PE. The protein and activity levels associated with coagulation, including protein C antigen, protein S antigen, protein S activity, anti-thrombin III antigen, and factor VIII, were significantly lower in patients with provoked PE than in those with unprovoked PE. Multivariate analysis showed that infection (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.4 to 7.4) and protein S activity (OR, 0.97; 95% CI, 0.95 to 0.99) were significantly associated with provoked PE. Protein S activity and presence of infection were important factors associated with provoked PE. We should pay attention to the presence of infection in patients with provoked PE.

  4. Evaluation of Electric Power Procurement Strategies by Stochastic Dynamic Programming

    Science.gov (United States)

    Saisho, Yuichi; Hayashi, Taketo; Fujii, Yasumasa; Yamaji, Kenji

    In deregulated electricity markets, the role of a distribution company is to purchase electricity from the wholesale electricity market at randomly fluctuating prices and to provide it to its customers at a given fixed price. Therefore the company has to take risk stemming from the uncertainties of electricity prices and/or demand fluctuation instead of the customers. The way to avoid the risk is to make a bilateral contact with generating companies or install its own power generation facility. This entails the necessity to develop a certain method to make an optimal strategy for electric power procurement. In such a circumstance, this research has the purpose for proposing a mathematical method based on stochastic dynamic programming and additionally considering the characteristics of the start-up cost of electric power generation facility to evaluate strategies of combination of the bilateral contract and power auto-generation with its own facility for procuring electric power in deregulated electricity market. In the beginning we proposed two approaches to solve the stochastic dynamic programming, and they are a Monte Carlo simulation method and a finite difference method to derive the solution of a partial differential equation of the total procurement cost of electric power. Finally we discussed the influences of the price uncertainty on optimal strategies of power procurement.

  5. Research and Simulation of the Electrical Vehicle Based Dynamical System

    Directory of Open Access Journals (Sweden)

    Ko-Chun Chen

    2015-01-01

    Full Text Available This study developed a dynamic model of electric vehicle system by using the MATLAB/Simulink tool. The vehicle model comprises two system components: an electrical system and a suspension system. This study also designed various road conditions for simulating the motion of vehicle traveling along a road. The results show that the electrical and suspension system parameters can be adjusted immediately to enhance passenger comfort. The findings of this research have practical teaching applications. Students can modify the vehicle model parameters byes using the MATLAB graphical user interface, allowing them to observe the motion of vehicle under various road conditions.

  6. Dynamic electrophoresis of charged colloids in an oscillating electric field.

    Science.gov (United States)

    Shih, Chunyu; Yamamoto, Ryoichi

    2014-06-01

    The dynamics of charged colloids in an electrolyte solution is studied using direct numerical simulations via the smoothed profile method. We calculated the complex electrophoretic mobility μ(ω) of the charged colloids under an oscillating electric field of frequency ω. We show the existence of three dynamically distinct regimes, determined by the momentum diffusion and ionic diffusion time scales. The present results agree well with approximate theories based on the cell model in dilute suspensions; however, systematic deviations between the simulation results and theoretical predictions are observed as the volume fraction of colloids is increased, similar to the case of constant electric fields.

  7. Electricity Market Stochastic Dynamic Model and Its Mean Stability Analysis

    Directory of Open Access Journals (Sweden)

    Zhanhui Lu

    2014-01-01

    Full Text Available Based on the deterministic dynamic model of electricity market proposed by Alvarado, a stochastic electricity market model, considering the random nature of demand sides, is presented in this paper on the assumption that generator cost function and consumer utility function are quadratic functions. The stochastic electricity market model is a generalization of the deterministic dynamic model. Using the theory of stochastic differential equations, stochastic process theory, and eigenvalue techniques, the determining conditions of the mean stability for this electricity market model under small Gauss type random excitation are provided and testified theoretically. That is, if the demand elasticity of suppliers is nonnegative and the demand elasticity of consumers is negative, then the stochastic electricity market model is mean stable. It implies that the stability can be judged directly by initial data without any computation. Taking deterministic electricity market data combined with small Gauss type random excitation as numerical samples to interpret random phenomena from a statistical perspective, the results indicate the conclusions above are correct, valid, and practical.

  8. Electric Vehicle (EV) Charging Management with Dynamic Distribution System Tariff

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Wu, Qiuwei; Østergaard, Jacob

    2011-01-01

    An electric vehicle (EV) charging schedule algorithm was proposed in this paper in order to charge EVs to meet EV users’ driving needs with the minimum EV charging cost and respect the local distribution system constraints. A day-ahead dynamic distribution system tariff scheme was proposed to avoid...

  9. Simultaneous dynamic electrical and structural measurements of functional materials

    Energy Technology Data Exchange (ETDEWEB)

    Vecchini, C.; Stewart, M.; Muñiz-Piniella, A.; Wooldridge, J. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Thompson, P.; McMitchell, S. R. C.; Bouchenoire, L.; Brown, S.; Wermeille, D.; Lucas, C. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Lepadatu, S. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Bikondoa, O.; Hase, T. P. A. [XMaS, The UK-CRG, ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Lesourd, M. [ESRF-The European Synchrotron, CS40220, F-38043, Grenoble Cedex 09 (France); Dontsov, D. [SIOS Meßtechnik GmbH, Am Vogelherd 46, 98693 Ilmenau (Germany); Cain, M. G. [National Physical Laboratory, Hampton Road, Teddington TW11 0LW (United Kingdom); Electrosciences Ltd., Farnham, Surrey GU9 9QT (United Kingdom)

    2015-10-15

    A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.

  10. Ferroelastic domain switching dynamics under electrical and mechanical excitations.

    Science.gov (United States)

    Gao, Peng; Britson, Jason; Nelson, Christopher T; Jokisaari, Jacob R; Duan, Chen; Trassin, Morgan; Baek, Seung-Hyub; Guo, Hua; Li, Linze; Wang, Yiran; Chu, Ying-Hao; Minor, Andrew M; Eom, Chang-Beom; Ramesh, Ramamoorthy; Chen, Long-Qing; Pan, Xiaoqing

    2014-05-02

    In thin film ferroelectric devices, switching of ferroelastic domains can significantly enhance electromechanical response. Previous studies have shown disagreement regarding the mobility or immobility of ferroelastic domain walls, indicating that switching behaviour strongly depends on specific microstructures in ferroelectric systems. Here we study the switching dynamics of individual ferroelastic domains in thin Pb(Zr0.2,Ti0.8)O3 films under electrical and mechanical excitations by using in situ transmission electron microscopy and phase-field modelling. We find that ferroelastic domains can be effectively and permanently stabilized by dislocations at the substrate interface while similar domains at free surfaces without pinning dislocations can be removed by either electric or stress fields. For both electrical and mechanical switching, ferroelastic switching is found to occur most readily at the highly active needle points in ferroelastic domains. Our results provide new insights into the understanding of polarization switching dynamics as well as the engineering of ferroelectric devices.

  11. Managing time-substitutable electricity usage using dynamic controls

    Science.gov (United States)

    Ghosh, Soumyadip; Hosking, Jonathan R.; Natarajan, Ramesh; Subramaniam, Shivaram; Zhang, Xiaoxuan

    2017-02-07

    A predictive-control approach allows an electricity provider to monitor and proactively manage peak and off-peak residential intra-day electricity usage in an emerging smart energy grid using time-dependent dynamic pricing incentives. The daily load is modeled as time-shifted, but cost-differentiated and substitutable, copies of the continuously-consumed electricity resource, and a consumer-choice prediction model is constructed to forecast the corresponding intra-day shares of total daily load according to this model. This is embedded within an optimization framework for managing the daily electricity usage. A series of transformations are employed, including the reformulation-linearization technique (RLT) to obtain a Mixed-Integer Programming (MIP) model representation of the resulting nonlinear optimization problem. In addition, various regulatory and pricing constraints are incorporated in conjunction with the specified profit and capacity utilization objectives.

  12. Water response to intense electric fields: A molecular dynamics study.

    Science.gov (United States)

    Marracino, Paolo; Liberti, Micaela; d'Inzeo, Guglielmo; Apollonio, Francesca

    2015-07-01

    This paper investigated polarization properties of water molecules in close proximity to an ionic charge in the presence of external electric fields by using an approach based on simulations at the atomic level. We chose sodium and chloride ions in water as examples of dilute ionic solutions and used molecular dynamics simulations to systematically investigate the influence of an external static electric field on structural, dipolar, and polarization properties of water near charged ions. Results showed that a threshold electric field higher than 10(8) V/m is needed to affect water polarization and increase mean dipole moment of water molecules close to the ion. A similar threshold holds for water permittivity profiles, although a field 10× higher is needed to ensure that water permittivity is almost constant independently of the position close to the ion. Electric fields of such intensities can greatly enhance polarizability of water in hydration shells around ions. © 2015 Wiley Periodicals, Inc.

  13. Managing time-substitutable electricity usage using dynamic controls

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Soumyadip; Hosking, Jonathan R.; Natarajan, Ramesh; Subramaniam, Shivaram; Zhang, Xiaoxuan

    2017-02-21

    A predictive-control approach allows an electricity provider to monitor and proactively manage peak and off-peak residential intra-day electricity usage in an emerging smart energy grid using time-dependent dynamic pricing incentives. The daily load is modeled as time-shifted, but cost-differentiated and substitutable, copies of the continuously-consumed electricity resource, and a consumer-choice prediction model is constructed to forecast the corresponding intra-day shares of total daily load according to this model. This is embedded within an optimization framework for managing the daily electricity usage. A series of transformations are employed, including the reformulation-linearization technique (RLT) to obtain a Mixed-Integer Programming (MIP) model representation of the resulting nonlinear optimization problem. In addition, various regulatory and pricing constraints are incorporated in conjunction with the specified profit and capacity utilization objectives.

  14. Modelling the Aggregated Dynamic Response of Electric Vehicles

    DEFF Research Database (Denmark)

    Ziras, Charalampos; Hu, Junjie; You, Shi

    2017-01-01

    There is an increasing interest in the use of electric vehicles (EVs) for providing fast frequency reserves due to their large installed capacity and their very fast response. Most works focus on scheduling and optimization and usually neglect their aggregated dynamic response, which is particula......There is an increasing interest in the use of electric vehicles (EVs) for providing fast frequency reserves due to their large installed capacity and their very fast response. Most works focus on scheduling and optimization and usually neglect their aggregated dynamic response, which....... Such approximations can be used in power system studies, in order to capture the dynamics of an EV population more accurately. Finally, we compare our approach to the most widely used in the literature, i.e. the averaging method where all EVs are represented with the population’s average values, and discuss the key...

  15. THE ANALISYS OF RAILWAY MULTI MOTORS ELECTRICAL DRIVE DYNAMIC

    Directory of Open Access Journals (Sweden)

    V. I. Khilmon

    2015-01-01

    Full Text Available The importance of multi motors electrical traction drive dynamic analysis is denoted by its large application in electrical driving railway vehicles. In this paper an analysis is presented for two inducton motors traction drive with frequency inverter, vector control, and speed sensors of each electrical drive. The goal of this work is the analysis of two induction motors electrical drive, taking into account parametric perturbations and also a limited moment of wheel-rail adhesion, by laboratory study and simulation. Because of difference between motor’s parameters, it is necessary for parallel work to select motors with identical resistances and inductive winding. For this purpose the parametric identification method was used for each electrical drive, and also for two parallel motors. The result of identification was used in control setting.The  slippage  of  the  traction  drives  is  difficult  to  reproduce  in  laboratory;  therefore a mathematical modeling and simulation of mechanical part with a traction force restriction, specific for railway transport, were carried out. The suggested simulation is built with account of elastic deformations in kinetic chain, transforming traction force. The model permits to study a dynamic system in various circumstances.The results of laboratory investigations and simulation of dynamic regimes for two motor electrical drives are presented in this article. The results of analysis show, that a minimal difference between any parameters of two motors, parallel connected to convertor, is important for the slippage stability.

  16. Nonlinear dynamics of semiconductors in strong THz electric fields

    DEFF Research Database (Denmark)

    Tarekegne, Abebe Tilahun

    weak THz and near infrared pulses as probes. Firstly, an intense THz pulse is used to study THz-induced impact ionization (IMI) dynamics in silicon. Local field enhancement by metallic dipole antenna arrays has been used to generate strong electric fields of several MV/cm in the hot spots near...... uniquely. Finally it is demonstrated for the first time that SiC can be tailored to have extremely fast THz-induced nonlinear behavior in moderate THz electric fields by addition of appropriate dopants. A 4H-SiC sample with high concentrations of nitrogen and boron dopants shows a nonlinear THz...

  17. Electric Vehicle Smart Charging using Dynamic Price Signal

    DEFF Research Database (Denmark)

    Martinenas, Sergejus; Pedersen, Anders Bro; Marinelli, Mattia

    2014-01-01

    With yearly increases in Electric Vehicle (EV) sales, the future for electric mobility continues to brighten, and with more vehicles hitting the roads every day, the energy requirements on the grid will increase, potentially causing low-voltage distribution grid congestion. This problem can...... proposed in this paper, involves a real-time control strategy for charging the EV using a dynamic price tariff, with the objective of minimizing the charging cost. Two different charging scenario are investigated, and the results are verified by experiments on a real Electric Vehicle. Finally, the costs......, however, be resolved by using intelligent EV charging strategies, commonly referred to as ”Smart Charging”. The basic approach involves modifying the default vehicle charging scheme of ”immediate charging”, to a more optimal one that is derived from insight into the current state of the grid. This work...

  18. Graphene: A Dynamic Platform for Electrical Control of Plasmonic Resonance

    DEFF Research Database (Denmark)

    Emani, Naresh Kumar; Kildishev, Alexander V.; Shalaev, Vladimir M.

    2015-01-01

    Graphene has recently emerged as a viable platform for integrated optoelectronic and hybrid photonic devices because of its unique properties. The optical properties of graphene can be dynamically controlled by electrical voltage and have been used to modulate the plasmons in noble metal nanostru......Graphene has recently emerged as a viable platform for integrated optoelectronic and hybrid photonic devices because of its unique properties. The optical properties of graphene can be dynamically controlled by electrical voltage and have been used to modulate the plasmons in noble metal...... nanostructures. Graphene has also been shown to support highly confined intrinsic plasmons, with properties that can be tuned in the wavelength range of 2 μm to 100 μm. Here we review the recent development in graphene-plasmonic devices and identify some of the key challenges for practical applications...

  19. Ultrafast carrier dynamics in graphene under a high electric field.

    Science.gov (United States)

    Tani, Shuntaro; Blanchard, François; Tanaka, Koichiro

    2012-10-19

    We investigated ultrafast carrier dynamics in graphene with near-infrared transient absorption measurement after intense half-cycle terahertz pulse excitation. The terahertz electric field efficiently drives the carriers, inducing large transparency in the near-infrared region. Theoretical calculations using the Boltzmann transport equation quantitatively reproduce the experimental findings. This good agreement suggests that the intense terahertz field should promote a remarkable impact ionization process and increase the carrier density.

  20. Directly calculating electrical conductivities of dense hydrogen from molecular dynamics

    Science.gov (United States)

    Ma, Qian; Kang, Dongdong; Dai, Jiayu

    2017-10-01

    The transport properties are important in warm and hot dense matter in which the Coulomb interaction is dominated in the scattering process. Density functional theory (DFT) is considered as an effective method to investigate the transport properties, but the dynamical collisions between particles are missed. Here we use an electron force field (eFF) method based molecular dynamics (MD) to include the electronic quantum effects to investigate the transport properties of warm dense hydrogen. The eFF method can be regarded as the development of wave packets molecular dynamics and it has been successfully used to describe the thermodynamics of hydrogen, Auger process in diamondoids, the equation of states for dense lithium. The most important point of eFF method is assuming that each electron is considered as a Gaussian wave packet controlled by position and size while ions are still charged points. The electrical conductivity is calculated via the correlation of electrical current. The results show that electronic quantum effects are important for the transport properties in warm dense hydrogen such as diffusion coefficient and electrical conductivity, which are much smaller than the results from DFT calculations.

  1. Nanosecond electric pulses modulate skeletal muscle calcium dynamics and contraction

    Science.gov (United States)

    Valdez, Chris; Jirjis, Michael B.; Roth, Caleb C.; Barnes, Ronald A.; Ibey, Bennett L.

    2017-02-01

    Irreversible electroporation therapy is utilized to remove cancerous tissues thru the delivery of rapid (250Hz) and high voltage (V) (1,500V/cm) electric pulses across microsecond durations. Clinical research demonstrated that bipolar (BP) high voltage microsecond pulses opposed to monophasic waveforms relieve muscle contraction during electroporation treatment. Our group along with others discovered that nanosecond electric pulses (nsEP) can activate second messenger cascades, induce cytoskeletal rearrangement, and depending on the nsEP duration and frequency, initiate apoptotic pathways. Of high interest across in vivo and in vitro applications, is how nsEP affects muscle physiology, and if nuances exist in comparison to longer duration electroporation applications. To this end, we exposed mature skeletal muscle cells to monopolar (MP) and BP nsEP stimulation across a wide range of electric field amplitudes (1-20 kV/cm). From live confocal microscopy, we simultaneously monitored intracellular calcium dynamics along with nsEP-induced muscle movement on a single cell level. In addition, we also evaluated membrane permeability with Yo-PRO-1 and Propidium Iodide (PI) across various nsEP parameters. The results from our findings suggest that skeletal muscle calcium dynamics, and nsEP-induced contraction exhibit exclusive responses to both MP and BP nsEP exposure. Overall the results suggest in vivo nsEP application may elicit unique physiology and field applications compared to longer pulse duration electroporation.

  2. Dynamic magnetic susceptibility and electrical detection of ferromagnetic resonance

    Science.gov (United States)

    Zhang, Yin; Wang, X. S.; Yuan, H. Y.; Kang, S. S.; Zhang, H. W.; Wang, X. R.

    2017-03-01

    The dynamic magnetic susceptibility of magnetic materials near ferromagnetic resonance (FMR) is very important in interpreting the dc voltage obtained in its electrical detection. Based on the causality principle and the assumption that the usual microwave absorption lineshape of a homogeneous magnetic material around FMR is Lorentzian, the general forms of the dynamic magnetic susceptibility of an arbitrary sample and the corresponding dc voltage lineshapes of its electrical detection were obtained. Our main findings are as follows. (1) The dynamic magnetic susceptibility is not a Polder tensor for a material with an arbitrary magnetic anisotropy. The two off-diagonal matrix elements of the tensor near FMR are not, in general, opposite to each other. However, the linear response coefficient of the magnetization to the total radio frequency (rf) field (the sum of the external and internal rf fields due to precessing magnetization is a quantity which cannot be measured directly) is a Polder tensor. This may explain why the two off-diagonal susceptibility matrix elements were always wrongly assumed to be opposite to each other in almost all analyses. (2) The frequency dependence of dynamic magnetic susceptibility near FMR is fully characterized by six real numbers, while its field dependence is fully characterized by seven real numbers. (3) A recipe of how to determine these numbers by standard microwave absorption measurements for a sample with an arbitrary magnetic anisotropy is proposed. Our results allow one to unambiguously separate the contribution of the anisotropic magnetoresistance to the dc voltage signals from the anomalous Hall effect. With these results, one can reliably extract the information of spin pumping and the inverse spin-Hall effect, and determine the spin-Hall angle. (4) In the case that resonance frequency is not sensitive to the applied static magnetic field, the field dependence of the matrix elements of dynamic magnetic susceptibility, as

  3. Influence of electrical sheet width on dynamic magnetic properties

    CERN Document Server

    Chevalier, T; Cornut, B

    2000-01-01

    Effects of the width of electrical steel sheets on dynamic magnetic properties are investigated by solving diffusion equation on the cross-section of the sheet. Linear and non-linear cases are studied, and are compared with measurement on Epstein frame. For the first one an analytical solution is found, while for the second, a 2D finite element simulation is achieved. The influence of width is highlighted for a width thickness ratio lower than 10. It is shown that the behaviour modification in such cases is conditioned by the excitation signal waveform, amplitude and also frequency.

  4. Atomistic modeling of metal surfaces under electric fields: direct coupling of electric fields to a molecular dynamics algorithm

    CERN Document Server

    Djurabekova, Flyura; Pohjonen, Aarne; Nordlund, Kai

    2011-01-01

    The effect of electric fields on metal surfaces is fairly well studied, resulting in numerous analytical models developed to understand the mechanisms of ionization of surface atoms observed at very high electric fields, as well as the general behavior of a metal surface in this condition. However, the derivation of analytical models does not include explicitly the structural properties of metals, missing the link between the instantaneous effects owing to the applied field and the consequent response observed in the metal surface as a result of an extended application of an electric field. In the present work, we have developed a concurrent electrodynamic–molecular dynamic model for the dynamical simulation of an electric-field effect and subsequent modification of a metal surface in the framework of an atomistic molecular dynamics (MD) approach. The partial charge induced on the surface atoms by the electric field is assessed by applying the classical Gauss law. The electric forces acting on the partially...

  5. Analysis methods for wind turbine control and electrical system dynamics

    Science.gov (United States)

    Hinrichsen, E. N.

    1995-01-01

    The integration of new energy technologies into electric power systems requires methods which recognize the full range of dynamic events in both the new generating unit and the power system. Since new energy technologies are initially perceived as small contributors to large systems, little attention is generally paid to system integration, i.e. dynamic events in the power system are ignored. As a result, most new energy sources are only capable of base-load operation, i.e. they have no load following or cycling capability. Wind turbines are no exception. Greater awareness of this implicit (and often unnecessary) limitation is needed. Analysis methods are recommended which include very low penetration (infinite bus) as well as very high penetration (stand-alone) scenarios.

  6. Selected Topics in Nonlinear Dynamics and Theoretical Electrical Engineering

    CERN Document Server

    Halang, Wolfgang; Mathis, Wolfgang; Chedjou, Jean; Li, Zhong

    2013-01-01

    This book contains a collection of recent advanced contributions in the field of nonlinear dynamics and synchronization, including selected applications in the area of theoretical electrical engineering. The present book is divided into twenty-one chapters grouped in five parts. The first part focuses on theoretical issues related to chaos and synchronization and their potential applications in mechanics, transportation, communication and security. The second part handles dynamic systems modelling and simulation with special applications to real physical systems and phenomena. The third part discusses some fundamentals of electromagnetics (EM) and addresses the modelling and simulation in some real physical electromagnetic scenarios. The fourth part mainly addresses stability concerns. Finally, the last part assembles some sample applications in the area of optimization, data mining, pattern recognition and image processing.

  7. Selected topics in nonlinear dynamics and theoretical electrical engineering

    CERN Document Server

    Halang, Wolfgang; Mathis, Wolfgang; Chedjou, Jean; Li, Zhong

    2013-01-01

    This book contains a collection of recent advanced contributions in the field of nonlinear dynamics and synchronization, including selected applications in the area of theoretical electrical engineering. The present book is divided into twenty-one chapters grouped in five parts. The first part focuses on theoretical issues related to chaos and synchronization and their potential applications in mechanics, transportation, communication and security. The second part handles dynamic systems modelling and simulation with special applications to real physical systems and phenomena. The third part discusses some fundamentals of electromagnetics (EM) and addresses the modelling and simulation in some real physical electromagnetic scenarios. The fourth part mainly addresses stability concerns. Finally, the last part assembles some sample applications in the area of optimization, data mining, pattern recognition and image processing.

  8. Dynamic Line Rating Oncor Electric Delivery Smart Grid Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Justin; Smith, Cale; Young, Mike; Donohoo, Ken; Owen, Ross; Clark, Eddit; Espejo, Raul; Aivaliotis, Sandy; Stelmak, Ron; Mohr, Ron; Barba, Cristian; Gonzalez, Guillermo; Malkin, Stuart; Dimitrova, Vessela; Ragsdale, Gary; Mitchem, Sean; Jeirath, Nakul; Loomis, Joe; Trevino, Gerardo; Syracuse, Steve; Hurst, Neil; Mereness, Matt; Johnson, Chad; Bivens, Carrie

    2013-05-04

    Electric transmission lines are the lifeline of the electric utility industry, delivering its product from source to consumer. This critical infrastructure is often constrained such that there is inadequate capacity on existing transmission lines to efficiently deliver the power to meet demand in certain areas or to transport energy from high-generation areas to high-consumption regions. When this happens, the cost of the energy rises; more costly sources of power are used to meet the demand or the system operates less reliably. These economic impacts are known as congestion, and they can amount to substantial dollars for any time frame of reference: hour, day or year. There are several solutions to the transmission constraint problem, including: construction of new generation, construction of new transmission facilities, rebuilding and reconductoring of existing transmission assets, and Dynamic Line Rating (DLR). All of these options except DLR are capital intensive, have long lead times and often experience strong public and regulatory opposition. The Smart Grid Demonstration Program (SGDP) project co-funded by the Department of Energy (DOE) and Oncor Electric Delivery Company developed and deployed the most extensive and advanced DLR installation to demonstrate that DLR technology is capable of resolving many transmission capacity constraint problems with a system that is reliable, safe and very cost competitive. The SGDP DLR deployment is the first application of DLR technology to feed transmission line real-time dynamic ratings directly into the system operation’s State Estimator and load dispatch program, which optimizes the matching of generation with load demand on a security, reliability and economic basis. The integrated Dynamic Line Rating (iDLR)1 collects transmission line parameters at remote locations on the lines, calculates the real-time line rating based on the equivalent conductor temperature, ambient temperature and influence of wind and solar

  9. Tensor-based dynamic reconstruction method for electrical capacitance tomography

    Science.gov (United States)

    Lei, J.; Mu, H. P.; Liu, Q. B.; Li, Z. H.; Liu, S.; Wang, X. Y.

    2017-03-01

    Electrical capacitance tomography (ECT) is an attractive visualization measurement method, in which the acquisition of high-quality images is beneficial for the understanding of the underlying physical or chemical mechanisms of the dynamic behaviors of the measurement objects. In real-world measurement environments, imaging objects are often in a dynamic process, and the exploitation of the spatial-temporal correlations related to the dynamic nature will contribute to improving the imaging quality. Different from existing imaging methods that are often used in ECT measurements, in this paper a dynamic image sequence is stacked into a third-order tensor that consists of a low rank tensor and a sparse tensor within the framework of the multiple measurement vectors model and the multi-way data analysis method. The low rank tensor models the similar spatial distribution information among frames, which is slowly changing over time, and the sparse tensor captures the perturbations or differences introduced in each frame, which is rapidly changing over time. With the assistance of the Tikhonov regularization theory and the tensor-based multi-way data analysis method, a new cost function, with the considerations of the multi-frames measurement data, the dynamic evolution information of a time-varying imaging object and the characteristics of the low rank tensor and the sparse tensor, is proposed to convert the imaging task in the ECT measurement into a reconstruction problem of a third-order image tensor. An effective algorithm is developed to search for the optimal solution of the proposed cost function, and the images are reconstructed via a batching pattern. The feasibility and effectiveness of the developed reconstruction method are numerically validated.

  10. The Dynamics of Electricity Demand and Comsumption in Nigeria: Application of the Bounds Testing Approach

    OpenAIRE

    Udo N. Ekpo; Chuku A. Chuku; Effiong, Ekpeno L.

    2011-01-01

    Clear insights about the dynamic nature of electricity demand and consumption is essential for capacity additions, investments and effective optimal energy policies. This paper provides background analysis of electricity demand and consumption trends in Nigeria, with the key determinants of electricity demand and the investment requirements clearly highlighted. Further, the paper utilizes the bounds testing approach to empirically investigate the dynamics of electricity demand and consumption...

  11. An analytical study of electric vehicle handling dynamics

    Science.gov (United States)

    Greene, J. E.; Segal, D. J.

    1979-01-01

    Hypothetical electric vehicle configurations were studied by applying available analytical methods. Elementary linearized models were used in addition to a highly sophisticated vehicle dynamics computer simulation technique. Physical properties of specific EV's were defined for various battery and powertrain packaging approaches applied to a range of weight distribution and inertial properties which characterize a generic class of EV's. Computer simulations of structured maneuvers were performed for predicting handling qualities in the normal driving range and during various extreme conditions related to accident avoidance. Results indicate that an EV with forward weight bias will possess handling qualities superior to a comparable EV that is rear-heavy or equally balanced. The importance of properly matching tires, suspension systems, and brake system front/rear torque proportioning to a given EV configuration during the design stage is demonstrated.

  12. Dynamic measurements of electrical conductivity in metastable intermolecular composites

    Science.gov (United States)

    Tasker, Douglas G.; Asay, Blaine W.; King, James C.; Sanders, V. Eric; Son, Steven F.

    2006-01-01

    Metastable intermolecular composite (MIC) materials are comprised of a mixture of oxidizer and fuel with particle sizes in the nanometer range. Dynamic electrical conductivity measurements have been performed on a reacting MIC material. Simultaneous optical measurements of the wavefront position have shown that the reaction and conduction fronts are coincident within 160 μm. It has been observed that MICs, like high explosives, are insulators before reaction is initiated. Once reaction is induced, there is a conduction zone that corresponds with the reaction zone behind the reaction front. Unlike detonating high explosives (HEs) where the conductivity profile is represented by an initial peak followed by an exponential decay of conductivity, the MIC conductivity profile is a gradual, irregular ramp which increases from zero over many microseconds. This supports other studies that show the MIC reaction process to be significantly different from detonating HEs. Static measurements of conductivity of pressed MIC pellets suggest that the electrical conduction is associated with chemical reaction in the MIC and not compaction effects alone.

  13. Dynamic Interaction between Cap & Trade and Electricity Markets

    Science.gov (United States)

    Jeev, Kumar

    Greenhouse Gases (GHG), such as Carbon-Dioxide (CO2), which is released in the atmosphere due to anthropogenic activities like power production, are now accepted as the main culprits for global warming. The Regional Greenhouse Gas Initiative (RGGI), an initiative of the North East and Mid-Atlantic States of the United States (US) for limiting the emission of GHG, has developed a regional cap-and-trade program for CO2 emissions for power plants. Existing cap-and-trade programs in US and Europe for Greenhouse Gases have recently been plagued by over-allocation. Carbon prices recently collapsed in all these markets during the global recession. Since then, there have been significant policy changes, which have resulted in the adoption of aggressive emission cap targets by most major carbon emission markets. This is expected to make carbon emissions availability more restrictive, raising the prices of these credits. These emissions markets are expected to have a major impact on the wholesale electricity markets. Two models to study the interaction of these two markets are presented. These models assess the impact of the emissions market on wholesale electricity prices. The first model characterizes the competition between two types of power plants (coal and gas) in both the electricity and emissions markets as a dynamic game using the Cournot approximation. Under this approximation, we find that in the Nash equilibrium the plants increase their permit allocation to high-demand periods and the marginal value of each credit for a plant is identical in all periods under their optimal equilibrium strategy. The second numerical model allows us to explicitly evaluate the closed loop equilibrium of the dynamic interaction of two competitors in these markets. We find that plants often try to corner the market and push prices all the way to the price cap. Power plants derive most of their profits from these extreme price regimes. In the experiments where trading is allowed

  14. Dynamic Hybrid Model for Short-Term Electricity Price Forecasting

    OpenAIRE

    Marin Cerjan; Marin Matijaš; Marko Delimar

    2014-01-01

    Accurate forecasting tools are essential in the operation of electric power systems, especially in deregulated electricity markets. Electricity price forecasting is necessary for all market participants to optimize their portfolios. In this paper we propose a hybrid method approach for short-term hourly electricity price forecasting. The paper combines statistical techniques for pre-processing of data and a multi-layer (MLP) neural network for forecasting electricity price and price spike det...

  15. Dynamic Modeling and Simulation of a Switched Reluctance Motor in a Series Hybrid Electric Vehicle

    OpenAIRE

    Siavash Sadeghi; Mojtaba Mirsalim; Arash Hassanpour Isfahani

    2010-01-01

    Dynamic behavior analysis of electric motors is required in order to accuratelyevaluate the performance, energy consumption and pollution level of hybrid electricvehicles. Simulation tools for hybrid electric vehicles are divided into steady state anddynamic models. Tools with steady-state models are useful for system-level analysiswhereas tools that utilize dynamic models give in-depth information about the behavior ofsublevel components. For the accurate prediction of hybrid electric vehicl...

  16. Acute generalized exanthematous pustulosis provoked by furosemide

    Directory of Open Access Journals (Sweden)

    Andżelika Schwann-Majewska

    2015-06-01

    Full Text Available Introduction. Acute generalized exanthematous pustulosis (AGEP is a skin disease characterized by the sudden appearance of generalized pustules, accompanied by elevated body temperature and neutrophilia. Objective. Presentation of a patient with AGEP provoked by furosemide. Case report. We present a case of a 65-year-old patient diagnosed with and treated for generalized pustular eruption, with fever and changes in laboratory tests. Numerous coexisting medical conditions and a great number of frequently changed drugs (ciprofloxacin, allopurinol, folic acid, calcium carbonate, cyclophosphamide, atorvastatin, betaxolol and furosemide hindered identification of the causative factor. Conclusions. On the basis of the medical history and clinical picture, the patient was diagnosed with generalized exanthematous pustulosis induced by furosemide.

  17. Photoinactivation related dynamics of ctenophore photoproteins: Insights from molecular dynamics simulation under electric-field.

    Science.gov (United States)

    Pashandi, Zaiddodine; Molakarimi, Maryam; Mohseni, Ammar; Sajedi, Reza H; Taghdir, Majid; Naderi-Manesh, Hossein

    2017-08-19

    Photoinactivation is a common phenomenon in bioluminescence ctenophore photoproteins (e.g mnemiopsin, berovin and BfosPP) with still unknown mechanism. The activity of coelenterate photoproteins (e.g aequorin), which has high structural similarity with ctenophore photoproteins, is not affected by light. Recently, we have characterized the effects of light on ctenophore photoprotein mnemiopsin, in different conformations, which has demonstrated light induced structural changes, uniquely secondary structures, of both apo and holo mnemiopsin. This paper is further expansion of our previous work, by applying molecular dynamics simulations to investigate photoinactivation related dynamics of berovin at atomistic level, in comparison with aequorin, under the influence of electric component of electromagnetic field. The results have indicated that the intense electric filed could influence structure of both berovin and aequorin but in different manner, whereas moderate electric field only effects on berovin's structure remarkably. In this case, increased helicity of residues E180-M193 and decreased helical contents of L38-D46 and L125-D138 segments are considerable in berovin as well as flexibility elevation of calcium binding loops. These changes cause structural expansion of berovin, especially at N-terminal domain, in direction of electric field. In conclusion, the induced structural changes of mentioned helical parts together with elevated fluctuation of their adjacent segments, N26-D46 and M193-Y206, indicate the influence of light on substrate stabilizing residues, Arg41 and Y204. This condition could presumably leads to inactivation of bioluminescence reaction due to separation of substrate from the cavity of the protein. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Use of Local Dynamic Electricity Prices for Indirect Control of DER Power Units

    DEFF Research Database (Denmark)

    Nørgård, Per Bromand; Isleifsson, Fridrik Rafn

    2013-01-01

    electricity prices for indirect control of active power. The local, dynamic electricity prices are realised as dynamic adjustments of the quasi-stationary global power price. The aims of the dynamic price adjustments are to prevent overloading of the grid, to reduce the grid power losses and to regulate...... the grid voltage. The algorithms generating the local prices are dynamically adjusted according to the actual realised responses to the dynamic prices. Results are presented from an adapted version of the control principle implemented and tested in DTUs experimental research power system, SYSLAB, including...... wind power, solar power, flexible load and electrical storage. The local power price generation is based on the actual Nord Pool DK2 Spot prices on hourly basis as the quasi-stationary global electricity price, and the local SYSLAB's power exchange with the national grid as basis for the dynamic price...

  19. Co-simulation Methodologies for Hybrid and Electric Vehicle Dynamics

    OpenAIRE

    Veintimilla Porlán, Julia

    2016-01-01

    In recent decades, full electric and hybrid electric vehicles have emerged as an alternative to conventional cars due to a range of factors, including environmental and economic aspects. These vehicles are the result of considerable efforts to seek ways of reducing the use of fossil fuel for vehicle propulsion. Sophisticated technologies such as hybrid and electric powertrains require careful study and optimization. Mathematical models play a key role at this point. Currently, many advanced m...

  20. Hyperventilation provokes symptoms of carpal tunnel syndrome.

    Science.gov (United States)

    Aslam, U; Afzal, S; Syed, Shakir

    2012-01-01

    Hyperventilation causes respiratory alkalosis. The nervous system is more excitable in alkalosis. This phenomenon can be observed as paraesthesia in fingers and toes as well as around the lips in anxious patients breathing rapidly. We wanted to test this phenomenon on already irritable nerves like the median nerve in carpal tunnel syndrome (CTS). We deployed 50 patients who came in to the day case unit for carpal tunnel decompression with electro-physiologically proven diagnosis. We devised a test whereby patients were made to hyperventilate under prescribed conditions and repeated Phalen's test and Tinel's sign for comparison. These were compared with a control group chosen randomly among hospital staff. 86% patients had a positive result which was just behind Phalen's test in sensitivity. It was also 100% specific as there were no false positives. Hyperventilation is a phenomenon which provokes carpal tunnel syndrome. Its clinical value remains to be seen due to cumbersome method and probable patient non-compliance but it is a new discovery. It may be useful in other irritable-nerve-syndromes as a test to add to our available armament. It may be an additional factor or a primary reason for nocturnal paraesthesias in CTS patients.

  1. Dynamics of Electricity Demand in Lesotho: A Kalman Filter Approach

    Directory of Open Access Journals (Sweden)

    Thamae Retselisitsoe Isaiah

    2015-04-01

    Full Text Available This study provides an empirical analysis of the time-varying price and income elasticities of electricity demand in Lesotho for the period 1995-2012 using the Kalman filter approach. The results reveal that economic growth has been one of the main drivers of electricity consumption in Lesotho while electricity prices are found to play a less significant role since they are monopoly-driven and relatively low when compared to international standards. These findings imply that increases in electricity prices in Lesotho might not have a significant impact on consumption in the short-run. However, if the real electricity prices become too high over time, consumers might change their behavior and sensitivity to price and hence, energy policymakers will need to reconsider their impact in the long-run. Furthermore, several exogenous shocks seem to have affected the sensitivity of electricity demand during the period prior to regulation, which made individuals, businesses and agencies to be more sensitive to electricity costs. On the other hand, the period after regulation has been characterized by more stable and declining sensitivity of electricity demand. Therefore, factors such as regulation and changes in the country’s economic activities appear to have affected both price and income elasticities of electricity demand in Lesotho.

  2. Plug-in hybrid electric vehicles in dynamical energy markets

    NARCIS (Netherlands)

    Kessels, J.T.B.A.; Bosch, P.P.J. van den

    2008-01-01

    The plug-in hybrid electric vehicle allows vehicle propulsion from multiple internal power sources. Electric energy from the grid can be utilized by means of the plug-in connection. An on-line energy management (EM) strategy is proposed to minimize the costs for taking energy from each power source.

  3. Dynamic electrical muscle stimulation (EMS) training of the ...

    African Journals Online (AJOL)

    Previous research on muscle strengthening using electrical stimulation has mainly focused on isometric training. Thus, the aim of the study was to investigate the effect of isokinetic and isotonic electrical muscle stimulation training on the strength of the quadriceps femoris muscle group. A quantitative, experimental ...

  4. Dynamic Hybrid Model for Short-Term Electricity Price Forecasting

    Directory of Open Access Journals (Sweden)

    Marin Cerjan

    2014-05-01

    Full Text Available Accurate forecasting tools are essential in the operation of electric power systems, especially in deregulated electricity markets. Electricity price forecasting is necessary for all market participants to optimize their portfolios. In this paper we propose a hybrid method approach for short-term hourly electricity price forecasting. The paper combines statistical techniques for pre-processing of data and a multi-layer (MLP neural network for forecasting electricity price and price spike detection. Based on statistical analysis, days are arranged into several categories. Similar days are examined by correlation significance of the historical data. Factors impacting the electricity price forecasting, including historical price factors, load factors and wind production factors are discussed. A price spike index (CWI is defined for spike detection and forecasting. Using proposed approach we created several forecasting models of diverse model complexity. The method is validated using the European Energy Exchange (EEX electricity price data records. Finally, results are discussed with respect to price volatility, with emphasis on the price forecasting accuracy.

  5. Quasi-Stationarity of Electric Power Grid Dynamics Based on a Spatially Embedded Kuramoto Model

    OpenAIRE

    H. Mangesius;S. Hirche;D. Obradovic

    2013-01-01

    A novel and simple network model that is capable to reproduce quasi-stationary behavior and propagation phenomena in electric power grid dynamics is introduced. A new Kuramoto approximation to distributed generator dynamics is obtained from combining a continuous spatial interaction function with a discrete lattice model representing generator positions and network structure over a continuous spatial domain. At hand of model properties and a numerical study quasi-stationarity of electric powe...

  6. High dynamic range electric field sensor for electromagnetic pulse detection

    National Research Council Canada - National Science Library

    Lin, Che-Yun; Wang, Alan X; Lee, Beom Suk; Zhang, Xingyu; Chen, Ray T

    2011-01-01

    ...) polymer Y-fed directional coupler for electromagnetic wave detection. This electrode-less, all optical, wideband electrical field sensor is fabricated using standard processing for E-O polymer photonic devices...

  7. Dynamic Reduction Effect of CO2 Gas Discharge in Introducing Electric Vehicles

    Science.gov (United States)

    Liu, Bin; Inaba, Tsuginori

    For this study, the dynamic reduction effect of CO2 gas discharge for change from internal combustion engines to electric vehicles, EVs, was investigated quantitatively. The Japanese power generation status, which shows characteristics of electricity generation, and optimized adjustment to electricity demand, load and environment was examined. Based on a CO2 gas discharge basic unit, the estimated reduction quantity of CO2 gas discharge from EVs was calculated. The reduction effect of CO2 gas discharge is expected to be 52% by changing gas-fuelled vehicles to EVs. However, the dynamic differential is only 19% reduction by using the thermal power and -2% if only the coal thermal power is used.

  8. Beam dynamics requirements for HL–LHC electrical circuits

    CERN Document Server

    Gamba, Davide; Cerqueira Bastos, Miguel; Coello De Portugal - Martinez Vazquez, Jaime Maria; De Maria, Riccardo; Giovannozzi, Massimo; Martino, Michele; Tomas Garcia, Rogelio

    2017-01-01

    A certain number of LHC magnets and relative electrical circuits will be replaced for the HL-LHC upgrade. The performance of the new circuits will need to be compatible with the current installation, and to provide the necessary improvements to meet the tight requirements of the new operational scenario. This document summarises the present knowledge of the performance and use of the LHC circuits and, based on this and on the new optics requirements, provides the necessary specifications for the new HL-LHC electrical circuits.

  9. System Dynamics Project : The case of Electricity in Shanghai

    NARCIS (Netherlands)

    Yang, Q.; Zhenpeng, Z.

    2014-01-01

    The increasing energy demand in China due to urbanization has made the study of different energy policies in big cities a crucial topic of discussion. This is a complex problem since the electricity market is a multi-actor system where various actors may have a great influence on the main issue we

  10. Review of the Dynamics of Coalescence and Demulsification by High-Voltage Pulsed Electric Fields

    Directory of Open Access Journals (Sweden)

    Ye Peng

    2016-01-01

    Full Text Available The coalescence of droplets in oil can be implemented rapidly by high-voltage pulse electric field, which is an effective demulsification dehydration technological method. At present, it is widely believed that the main reason of pulse electric field promoting droplets coalescence is the dipole coalescence and oscillation coalescence in pulse electric field, and the optimal coalescence pulse electric field parameters exist. Around the above content, the dynamics of high-voltage pulse electric field promoting the coalescence of emulsified droplets is studied by researchers domestically and abroad. By review, the progress of high-voltage pulse electric field demulsification technology can get a better understanding, which has an effect of throwing a sprat to catch a whale on promoting the industrial application.

  11. Electric Potential and Electric Field Imaging with Dynamic Applications: 2017 Research Award Innovation

    Science.gov (United States)

    Generazio, Ed

    2017-01-01

    The technology and methods for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field may be used for illuminating volumes to be inspected with EFI. The baseline sensor technology (e-Sensor) and its construction, optional electric field generation (quasi-static generator), and current e- Sensor enhancements (ephemeral e-Sensor) are discussed. Critical design elements of current linear and real-time two-dimensional (2D) measurement systems are highlighted, and the development of a three dimensional (3D) EFI system is presented. Demonstrations for structural, electronic, human, and memory applications are shown. Recent work demonstrates that phonons may be used to create and annihilate electric dipoles within structures. Phonon induced dipoles are ephemeral and their polarization, strength, and location may be quantitatively characterized by EFI providing a new subsurface Phonon-EFI imaging technology. Initial results from real-time imaging of combustion and ion flow, and their measurement complications, will be discussed. These new EFI capabilities are demonstrated to characterize electric charge distribution creating a new field of study embracing areas of interest including electrostatic discharge (ESD) mitigation, crime scene forensics, design and materials selection for advanced sensors, combustion science, on-orbit space potential, container inspection, remote characterization of electronic circuits and level of activation, dielectric morphology of structures, tether integrity, organic molecular memory, atmospheric science, and medical diagnostic and treatment efficacy applications such as cardiac polarization wave propagation and electromyography imaging.

  12. Monitoring of impact dynamics on carbon nanotube multiscale glass fiber composites by means of electrical measurements

    Science.gov (United States)

    Sánchez-Romate, Xoan F.; Sbarufatti, Claudio; Scaccabarozzi, Diego; Cinquemani, Simone; Jiménez-Suárez, Alberto; Güemes, Alfredo; Ureña, Alejandro

    2017-04-01

    Electrical measurements of carbon nanotube multiscale GFRPs have been carried out for the monitoring of low velocity impact dynamics. To achieve that purpose, several plates have been fed by a power supply and a high frequency acquisition system has been used. Electrical measurements show that there is an initial decrease of electrical resistance due to plate compression, followed by an increase due to tunneling effect of carbon nanotubes. Finally, the effect of mechanical rebound is correlated to drop rise cycles of the electrical resistance. The sensitivity of the measured signals is also correlated with the impact energy and the electrodes disposition. Thus, the proposed method proves the validity and applicability of carbon nanotubes to characterize the low-velocity impact dynamics of a composite laminate.

  13. Potential of an electric prosthesis for dynamic facial reanimation.

    Science.gov (United States)

    Griffin, Garrett R; Kim, Jennifer C

    2011-09-01

    Chronic facial paralysis is a devastating condition with severe functional and emotional consequences. The current surgical armamentarium permits the predictable reestablishment of a protective blink as well as good resting symmetry. Yet the ultimate goal of symmetric, spontaneous emotional expression remains elusive despite significant progress in the areas of peripheral nerve grafting and free tissue transfer. This commentary explores the possibility of an implantable electrical prosthesis for facial reanimation. It reviews animal studies supporting this concept as well as recent human data suggesting that such an implant could rescue denervated facial musculature, thus overcoming a major hurdle for existing reanimation techniques.

  14. Electric-field-driven dynamics of magnetic domain walls in magnetic nanowires patterned on ferroelectric domains

    OpenAIRE

    Wiele, Ben Van de; Leliaert, Jonathan; Franke, Kévin J A; Dijken, Sebastiaan van

    2016-01-01

    Strong coupling of magnetic domain walls onto straight ferroelastic boundaries of a ferroelectric layer enables full and reversible electric-field control of magnetic domain wall motion. In this paper, the dynamics of this new driving mechanism is analyzed using micromagnetic simulations. We show that transverse domain walls with a near-180° spin structure are stabilized in magnetic nanowires and that electric fields can move these walls with high velocities. Above a critical velocity, which ...

  15. Dynamic Conditional Correlation between Electricity and Stock markets during the Financial Crisis in Greece

    OpenAIRE

    Papaioannou, Panagiotis G.; Papaioannou, George P.; Siettos, Kostas; Stratigakos, Akylas; Dikaiakos, Christos

    2017-01-01

    Liberalization of electricity markets has increasingly created the need for understanding the volatility and correlation structure between electricity and financial markets. This work reveals the existence of structural changes in correlation patterns among these two markets and links the changes to both fundamentals and regulatory conditions prevailing in the markets, as well as the current European financial crisis. We apply a Dynamic Conditional Correlation (DCC) GARCH model to a set of ma...

  16. Determination of dynamic pressure on infinite piezoelectric hollow cylinder from electric potential difference measurement

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.M. [Department of Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027 (China)], E-mail: wanghuiming@zju.edu.cn; Ding, H.J. [Department of Civil Engineering, College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310027 (China)

    2009-06-15

    An analytical method is developed for evaluating the dynamic pressure acted at the surface of infinite piezoelectric hollow cylinder by measuring the electric potential difference between the internal and external surfaces. By virtue of the separation of variables method and the orthogonal expansion technique, the inverse boundary problem is transformed to a second kind Volterra integral equation about the unknown dynamic pressure. The interpolation method is employed to solve the integral equation and the dynamic pressure is determined. The present method is suitable for the hollow cylinder with arbitrary thickness subjected to arbitrary dynamic pressure. Numerical experiments are also presented.

  17. Household electricity consumers’ incentive to choose dynamic pricing under different taxation schemes

    DEFF Research Database (Denmark)

    Katz, Jonas; Kitzing, Lena; Schröder, Sascha Thorsten

    2018-01-01

    vehicles has now reinforced interest in flexible demand and dynamic pricing. With a roll-out of smart metering one important technical hurdle is going to be cleared, and dynamic retail pricing may soon become an eligible option for many households. We quantify the potential incentives to adopt new pricing...... observations in the Danish market. We calculate potential savings from dynamic pricing and show how the choice of electricity taxation technique may hamper or enhance potential benefits. In the light of switching costs, our results suggest that the combination of smart meter roll-out and dynamic pricing...

  18. A dynamic oppositional biogeography-based optimization approach for time-varying electrical impedance tomography.

    Science.gov (United States)

    Rashid, A; Kim, S; Liu, D; Kim, K Y

    2016-06-01

    Dynamic electrical impedance tomography-based image reconstruction using conventional algorithms such as the extended Kalman filter often exhibits inferior performance due to the presence of measurement noise, the inherent ill-posed nature of the problem and its critical dependence on the selection of the initial guess as well as the state evolution model. Moreover, many of these conventional algorithms require the calculation of a Jacobian matrix. This paper proposes a dynamic oppositional biogeography-based optimization (OBBO) technique to estimate the shape, size and location of the non-stationary region boundaries, expressed as coefficients of truncated Fourier series, inside an object domain using electrical impedance tomography. The conductivity of the object domain is assumed to be known a priori. Dynamic OBBO is a novel addition to the family of dynamic evolutionary algorithms. Moreover, it is the first such study on the application of dynamic evolutionary algorithms for dynamic electrical impedance tomography-based image reconstruction. The performance of the algorithm is tested through numerical simulations and experimental study and is compared with state-of-the-art gradient-based extended Kalman filter. The dynamic OBBO is shown to be far superior compared to the extended Kalman filter. It is found to be robust to measurement noise as well as the initial guess, and does not rely on a priori knowledge of the state evolution model.

  19. Modeling hourly electricity dynamics for policy making in long-term scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Pina, Andre, E-mail: andre.pina@ist.utl.pt [Center for Innovation, Technology and Policy Research - IN, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); MIT-Portugal Program, Sustainable Energy Systems Focus Area (Portugal); Silva, Carlos [IDMEC, Instituto Superior Tecnico, Technical University of Lisbon (Portugal); MIT-Portugal Program, Sustainable Energy Systems Focus Area (Portugal); Ferrao, Paulo [Center for Innovation, Technology and Policy Research - IN, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal); MIT-Portugal Program, Sustainable Energy Systems Focus Area (Portugal)

    2011-09-15

    Energy policies are often related to the global effort in reducing greenhouse gas emissions through increased use of renewable energies in electricity production. The impact of these policies is usually calculated by energy planning tools. However, the modeling methodologies most currently used are not adequate to simulate long-term scenarios while considering the hourly dynamics of supply and demand. This paper presents an extension of the TIMES energy planning tool for investment decisions in electricity production that considers seasonal, daily and hourly supply and demand dynamics. The inclusion of these dynamics enables the model to produce more accurate results in what concerns the impact of introducing energy efficiency policies and the increased use of renewable energies. The model was validated in Sao Miguel (Azores, Portugal) for the years 2006-2009, where a comparison with real data showed that the model can simulate the supply and demand dynamics. Further, the long-term analysis shows that the inclusion of these dynamics contributes to a better assessment of the renewable energy potential, suggests the postponement of investments in new generation capacity, and demonstrates that using fine time resolution modeling is very valuable for the design of effective policy measures under high renewable penetration energy systems. - Highlights: > We develop a high temporal resolution TIMES model for long-term policy analysis. > The model is capable of considering hourly electricity supply and demand dynamics. > Lower resolution models can overestimate the optimum amount of renewable energies. > Modeling hourly dynamics of policies can help avoid non cost-effective investments.

  20. The quantum dynamics of mesoscopic discrete-charge electric circuits

    Directory of Open Access Journals (Sweden)

    F Kheirandish

    2008-07-01

    Full Text Available   The quantum dynamics of a charged particle in an infinite chain of single-state quantum wells, in tight-binding approximation and under the action of an arbitrary time-dependent external field is investigated. The connection between the Hamiltonian description of this model and the Hamiltonian of a discrete-charge mesoscopic quantum circuit is elucidated. Based on this connection, the persistent current on a L-design nondissipative circuit is obtained.

  1. The plasma wave and quasi-static electric field instrument /PWI/ for dynamics Explorer-A

    Science.gov (United States)

    Shawhan, S. D.; Gurnett, D. A.; Odem, D. L.; Helliwell, R. A.; Park, C. G.

    1981-01-01

    It is explained that the Plasma Wave Instrument (PWI) on Dynamics Explorer-A measures both plasma wave phenomena and quasi-static electric fields. The quasi-static electric fields are measured parallel to the spin axis of the spacecraft in a range of 2 mV/m to 2 V/m and perpendicular to the spin axis 0.5 mV/m to 2 V/m at 16 samples/s. The ac electric field sensors include a 200-m tip-to-tip long wire antenna and a 0.6-m short electric antenna, both of which are perpendicular to the spin axis, and a 9-m tip-to-tip tubular antenna parallel to the spin axis. AC electric wave fields are measured over a frequency range of 1 Hz to 2 MHz and over an amplitude range of 0.03 microvolt/m to 100 mV/m.

  2. Dynamically assisted Sauter-Schwinger effect in inhomogeneous electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Christian; Schützhold, Ralf [Fakultät für Physik, Universität Duisburg-Essen,Lotharstrasse 1, 47057 Duisburg (Germany)

    2016-02-24

    Via the world-line instanton method, we study electron-positron pair creation by a strong (but sub-critical) electric field of the profile E/cosh{sup 2} (kx) superimposed by a weaker pulse E{sup ′}/cosh{sup 2} (ωt). If the temporal Keldysh parameter γ{sub ω}=mω/(qE) exceeds a threshold value γ{sub ω}{sup crit} which depends on the spatial Keldysh parameter γ{sub k}=mk/(qE), we find a drastic enhancement of the pair creation probability — reporting on what we believe to be the first analytic non-perturbative result for the interplay between temporal and spatial field dependences E(t,x) in the Sauter-Schwinger effect. Finally, we speculate whether an analogous effect (drastic enhancement of tunneling probability) could occur in other scenarios such as stimulated nuclear decay, for example.

  3. Dynamic frequency tuning of electric and magnetic metamaterial response

    Science.gov (United States)

    O'Hara, John F; Averitt, Richard; Padilla, Willie; Chen, Hou-Tong

    2014-09-16

    A geometrically modifiable resonator is comprised of a resonator disposed on a substrate, and a means for geometrically modifying the resonator. The geometrically modifiable resonator can achieve active optical and/or electronic control of the frequency response in metamaterials and/or frequency selective surfaces, potentially with sub-picosecond response times. Additionally, the methods taught here can be applied to discrete geometrically modifiable circuit components such as inductors and capacitors. Principally, controlled conductivity regions, using either reversible photodoping or voltage induced depletion activation, are used to modify the geometries of circuit components, thus allowing frequency tuning of resonators without otherwise affecting the bulk substrate electrical properties. The concept is valid over any frequency range in which metamaterials are designed to operate.

  4. Nonlinear dynamic response of an electrically actuated imperfect microbeam resonator

    KAUST Repository

    Ruzziconi, Laura

    2013-08-04

    We present a study of the dynamic behavior of a MEMS device constituted of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. Extensive experimental investigation is conducted, where the main imperfections coming from microfabrication are detected and the nonlinear dynamics are explored at increasing values of electrodynamic excitation, in a neighborhood of the first symmetric resonance. The nonlinear behavior is highlighted, which includes ranges of multistability, where the non-resonant and the resonant branch coexist, and intervals where superharmonic resonances are clearly visible. Numerical simulations are performed. Initially, two single mode reduced-order models are considered. One is generated via the Galerkin technique, and the other one via the combined use of the Ritz method and the Padé approximation. Both of them are able to provide a satisfactory agreement with the experimental data. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Their computational efficiency is discussed in detail, since this is an essential aspect for systematic local and global simulations. Finally, the theoretical analysis is further improved and a two-degree-of-freedom reduced-order model is developed, which is capable also to capture the measured second symmetric superharmonic resonance. Despite the apparent simplicity, it is shown that all the proposed reduced-order models are able to describe the experimental complex nonlinear dynamics of the device accurately and properly, which validates the proposed theoretical approach. Copyright © 2013 by ASME.

  5. Dynamic Modeling and Simulation on a Hybrid Power System for Electric Vehicle Applications

    OpenAIRE

    Hong-Wen He; Rui Xiong; Yu-Hua Chang

    2010-01-01

    Hybrid power systems, formed by combining high-energy-density batteries and high-power-density ultracapacitors in appropriate ways, provide high-performance and high-efficiency power systems for electric vehicle applications. This paper first establishes dynamic models for the ultracapacitor, the battery and a passive hybrid power system, and then based on the dynamic models a comparative simulation between a battery only power system and the proposed hybrid power system was done under the UD...

  6. Primary, secondary and tertiary frequency control in dynamic security analyses of electric power interconnections

    Directory of Open Access Journals (Sweden)

    Ivanović Milan

    2012-01-01

    Full Text Available This paper presents the incorporation of primary, secondary and tertiary frequency control in the dynamic security analyses of electric power interconnections. This was done in accordance with the wider environment of the existing state of the Serbian power system. The improved software for dynamic security analysis has been tested on the regional transmission network, which includes power systems of Serbia, Montenegro, Bosnia and Herzegovina, Croatia, Hungary, Macedonia, Romania, Bulgaria, Greece and Albania.

  7. Thermo-Magneto-Electric Currents with Dynamical Magnetization Inhomogeneities

    Science.gov (United States)

    Santosh, Kumar Kudtarkar

    2011-09-01

    We study the effect of potential and thermal gradient induced non-equilibrium magnetization in quasi 1-d itinerant magnets. A semi-phenomenological theory is employed in conjunction with the drift-diffusion model for this study. Using the methods of non-equilibrium thermodynamics, we derive the transport currents corresponding to charge, heat, and magnetization flows in the presence of non-equilibrium magnetization textures. It is shown how time-dependent magnetic textures give rise to charge and thermal currents even in the absence of external potential and thermal gradients through spin pumping. The presence of dynamical textures also affect the thermodynamic parameters of the system. As an application, we consider the case of a helimagnet.

  8. Complex Phenomena Understanding in Electricity through Dynamically Linked Concrete and Abstract Representations

    Science.gov (United States)

    Taramopoulos, A.; Psillos, D.

    2017-01-01

    The present study investigates the impact of utilizing virtual laboratory environments combining dynamically linked concrete and abstract representations in investigative activities on the ability of students to comprehend simple and complex phenomena in the field of electric circuits. Forty-two 16- to 17-year-old high school students participated…

  9. The Contribution of Matched Envelope Dynamic Range to the Binaural Benefits in Simulated Bilateral Electric Hearing

    Science.gov (United States)

    Chen, Fei; Wong, Lena L. N.; Qiu, Jianxin; Liu, Yehai; Azimi, Behnam; Hu, Yi

    2013-01-01

    Purpose: This study examined the effects of envelope dynamic-range mismatch on the intelligibility of Mandarin speech in noise by simulated bilateral electric hearing. Method: Noise-vocoded Mandarin speech, corrupted by speech-shaped noise at 5 and 0 dB signal-to-noise ratios, was presented unilaterally or bilaterally to 10 normal-hearing…

  10. Dynamic Model of a Wind Turbine for the Electric Energy Generation

    Directory of Open Access Journals (Sweden)

    José de Jesús Rubio

    2014-01-01

    Full Text Available A novel dynamic model is introduced for the modeling of the wind turbine behavior. The objective of the wind turbine is the electric energy generation. The analytic model has the characteristic that considers a rotatory tower. Experiments show the validity of the proposed method.

  11. Dynamics and control of Stirling engines in a 15 kWe solar electric generation concept

    Science.gov (United States)

    Das, R. L.; Bahrami, K. A.

    1979-01-01

    This paper discusses the application of kinematic and free piston Stirling engines in a 15 kWe dish-electric approach for solar thermal electric generation. Initially, the principle of operation of Stirling engines in solar thermal electric generation is discussed. Then, under certain simplifying assumptions, mathematical models describing the dynamic operation of the kinematic and free piston Stirling engines are developed. It is found that the engine dynamics may be approximated by second order models. Control mechanisms for both types of Stirling engines are discussed. An approach based on the modulation of the working fluid mean pressure is presented. It is concluded that this approach offers a fast and effective means of control. The free piston Stirling engine, being a thermally driven mechanical oscillator, presents unique control requirements. These are discussed in this paper.

  12. Thyroid Storm Provoked by Interleukin-2 Therapy for Metastatic Melanoma

    Directory of Open Access Journals (Sweden)

    Yao-Chung Liu

    2014-06-01

    Full Text Available With the growing use of immunotherapy in the treatment of cancer and autoimmune disease, severe autoimmune thyroid dysfunction may be provoked at an increasing rate. We herein report a 49-year-old male patient experiencing a life- threatening thyroid storm provoked by interleukin-2 (IL-2. This was a case of pulmonary metastasis of melanoma without a previous history of thyroid dysfunction. For the metastatic melanoma, he underwent combined immunochemotherapy including dacarbazine and IL-2. The 3rd course of immunochemotherapy was complicated with a thyroid storm manifested by high fever, tachycardia and even transient cardiac arrest. Fortunately, he recovered eventually from this crisis by immediate resuscitation followed by antithyroid dugs. Our case highlights the rare complication of a thyroid storm provoked by IL-2 treatment. Precaution against autoimmune thyroid dysfunction is required during treatment with IL-2 and probably also other kinds of newly-developed immunotherapy to avoid life-threatening complications.

  13. Transportation and dynamic networks: Models, theory, and applications to supply chains, electric power, and financial networks

    Science.gov (United States)

    Liu, Zugang

    Network systems, including transportation and logistic systems, electric power generation and distribution networks as well as financial networks, provide the critical infrastructure for the functioning of our societies and economies. The understanding of the dynamic behavior of such systems is also crucial to national security and prosperity. The identification of new connections between distinct network systems is the inspiration for the research in this dissertation. In particular, I answer two questions raised by Beckmann, McGuire, and Winsten (1956) and Copeland (1952) over half a century ago, which are, respectively, how are electric power flows related to transportation flows and does money flow like water or electricity? In addition, in this dissertation, I achieve the following: (1) I establish the relationships between transportation networks and three other classes of complex network systems: supply chain networks, electric power generation and transmission networks, and financial networks with intermediation. The establishment of such connections provides novel theoretical insights as well as new pricing mechanisms, and efficient computational methods. (2) I develop new modeling frameworks based on evolutionary variational inequality theory that capture the dynamics of such network systems in terms of the time-varying flows and incurred costs, prices, and, where applicable, profits. This dissertation studies the dynamics of such network systems by addressing both internal competition and/or cooperation, and external changes, such as varying costs and demands. (3) I focus, in depth, on electric power supply chains. By exploiting the relationships between transportation networks and electric power supply chains, I develop a large-scale network model that integrates electric power supply chains and fuel supply markets. The model captures both the economic transactions as well as the physical transmission constraints. The model is then applied to the New

  14. Beller Lectureship: Dynamics of skyrmions under electric current

    Science.gov (United States)

    Nagaosa, Naoto

    2013-03-01

    Current-driven motion of the skyrmions and skyrmion crystal is attracting intense attention because of the very small critical current density, but the microscopic mechanism of their motion is not yet explored. In this talk, I will present a numerical simulation of the Landau-Lifshitz-Gilbert (LLG) equation and an analytic theory, which reveals a remarkably robust and universal current-velocity relation of the skyrmion motion driven by the spin transfer torque unaffected by either impurities or nonadiabatic effect in sharp contrast to the case of domain wall or spin helix. This is due to the peculiar dynamics of skyrmions characterized by inherent absence of the intrinsic pinning and flexible shape-deformation of skyrmions so as to avoid pinning centers. The effect of the constricted geometry will be also discussed. This work has been done in collaboration with J. Iwasaki and M. Mochizuki. This work was supported by Grant-in-Aids for Scientific Research (No. 24224009) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST).

  15. The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

    Directory of Open Access Journals (Sweden)

    Mingying Huo

    2017-01-01

    Full Text Available Displaced solar orbits for spacecraft propelled by electric sails are investigated. Since the propulsive thrust is induced by the sail attitude, the orbital and attitude dynamics of electric-sail-based spacecraft are coupled and required to be investigated together. However, the coupled dynamics and control of electric sails have not been discussed in most published literatures. In this paper, the equilibrium point of the coupled dynamical system in displaced orbit is obtained, and its stability is analyzed through a linearization. The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit system. Numerical simulations show that the proposed strategy can control the coupled system and a small torque can stabilize both the attitude and orbit. In order to generate the control force and torque, the voltage distribution problem is studied in an optimal framework. The numerical results show that the control force and torque of electric sail can be realized by adjusting the voltage distribution of charged tethers.

  16. The study of the dynamics of erythrocytes under the influence of an external electric field

    Science.gov (United States)

    Mamaeva, Sargylana N.; Maksimov, Georgy V.; Antonov, Stepan R.

    2017-11-01

    A mathematical model is considered for the determination of the surface charge of an erythrocyte with its shape approximated by a surface of revolution of the second order, and the investigation of the dynamics of erythrocytes under the influence of an external electric field. In the first part of this work, the electrical surface charge of the erythrocyte of the patient was calculated with the assumption that the change in the shape and size of the red blood cells leads to stabilization of the electric field, providing a normal electrostatic repulsion. In the second part of the work, the research results of dynamics of changes in the morphology of erythrocytes under the influence of an external electric field depending on the values of their surface charge and resistance of blood plasma is presented. In the course of the work, the dependence of the surface charge of red blood cells from their shape and size is presented. The determination of the relationship between the value of the charge field and the surface of erythrocytes in norm and in pathology is shown. The dependence of the velocity of the erythrocytes on the characteristics of the external electric field, surface charge of the erythrocyte and properties of the medium is obtained. The results of this study can be applied indirectly to diagnose diseases and to develop recommendations for experimental studies of hemodynamics under the influence of various external physical factors.

  17. Do stages of dentistry training affect anxiety provoking situations ...

    African Journals Online (AJOL)

    ... coping with children were the anxiety provoking situations that showed statistically significant difference in the 3 studied training stages of dentistry. Bonferroni post‑hoc analysis significant difference was in the preclinical and clinical students' pair for getting diagnosis wrong, not developing radiograph properly and coping ...

  18. Foods provoking and alleviating symptoms in gastroparesis: patient experiences.

    Science.gov (United States)

    Wytiaz, Victoria; Homko, Carol; Duffy, Frank; Schey, Ron; Parkman, Henry P

    2015-04-01

    Nutritional counseling for gastroparesis focuses on reduction of meal size, fiber, and fat to control symptoms. The tolerance of gastroparesis patients for particular foods is largely anecdotal. The aim of this study was to identify and characterize foods provoking or alleviating gastroparesis symptoms. Gastroparesis patients completed: (1) Demographic Questionnaire; (2) Patient Assessment of Upper GI Symptoms; (3) Food Toleration and Aversion survey asking patients about experiences when eating certain foods utilizing a scale from -3 (greatly worsening symptoms) to +3 (greatly improving symptoms). Descriptive qualities (acidic, fatty, spicy, roughage-based, bitter, salty, bland, and sweet) were assigned to foods. Forty-five gastroparesis patients participated (39 idiopathic gastroparesis). Foods worsening symptoms included: orange juice, fried chicken, cabbage, oranges, sausage, pizza, peppers, onions, tomato juice, lettuce, coffee, salsa, broccoli, bacon, and roast beef. Saltine crackers, jello, and graham crackers moderately improved symptoms. Twelve additional foods were tolerated by patients (not provoking symptoms): ginger ale, gluten-free foods, tea, sweet potatoes, pretzels, white fish, clear soup, salmon, potatoes, white rice, popsicles, and applesauce. Foods provoking symptoms were generally fatty, acidic, spicy, and roughage-based. The foods shown to be tolerable were generally bland, sweet, salty, and starchy. This study identified specific foods that worsen as well as foods that may help alleviate symptoms of gastroparesis. Foods that provoked symptoms differed in quality from foods that alleviated symptoms or were tolerable. The results of this study illustrate specific examples of foods that aggravate or improve symptoms and provide suggestions for a gastroparesis diet.

  19. Are seizures in the setting of sleep deprivation provoked?

    Science.gov (United States)

    Lawn, Nicholas; Lieblich, Sam; Lee, Judy; Dunne, John

    2014-04-01

    It is generally accepted that sleep deprivation contributes to seizures. However, it is unclear whether a seizure occurring in the setting of sleep deprivation should be considered as provoked or not and whether this is influenced by seizure type and etiology. This information may have an important impact on epilepsy diagnosis and management. We prospectively analyzed the influence of sleep deprivation on the risk of seizure recurrence in patients with first-ever unprovoked seizures and compared the findings with patients with first-ever provoked seizures. Of 1026 patients with first-ever unprovoked seizures, 204 (20%) were associated with sleep deprivation. While the overall likelihood of seizure recurrence was slightly lower in sleep-deprived patients with first-ever seizures (log-rank p=0.03), sleep deprivation was not an independent predictor of seizure recurrence on multivariate analysis. Seizure recurrence following a first-ever unprovoked seizure associated with sleep deprivation was far more likely than for 174 patients with a provoked first-ever seizure (log-rank psleep deprivation should not be regarded as provoked. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Phenomenon of isomorphic provoking responses in cases of limited scleroderma

    Directory of Open Access Journals (Sweden)

    Talnikova Е.Е.

    2015-09-01

    Full Text Available The article presents the historical origin of the term "Koebner phenomenon". The literature data reflect the etiology, pathogenesis and epidemiology of isomorphic mechanisms provoking responses in lichen planus, psoriasis, scleroder-ma, syphilis. Variants of the Koebner phenomenon's classifications are given. The clinical cases of limited scleroderma after mechanical injury are described.

  1. Brief communication "Modeling tornado dynamics and the generation of infrasound, electric and magnetic fields"

    Directory of Open Access Journals (Sweden)

    E. D. Schmitter

    2010-02-01

    Full Text Available Recent observations endorse earlier measurements of time varying electric and magnetic fields generated by tornadoes and dust devils. These signals may provide a means for early warning but together with a proper modeling approach can also provide insight into geometry and dynamics of the vortices. Our model calculations show the existence of pressure resonances characterized as acoustic duct modes with well defined frequencies. These resonances not only generate infrasound but also modulate the charge density and the velocity field and in this way lead to electric and magnetic field oscillations in the 0.5–20-Hz range that can be monitored from a distance of several kilometers.

  2. Simulational studies of epitaxial semiconductor superlattices: Quantum dynamical phenomena in ac and dc electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, Joseph [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    Using high-accuracy numerical methods the author investigates the dynamics of independent electrons in both ideal and realistic superlattices subject to arbitrary ac and/or dc electric fields. For a variety of superlattice potentials, optically excited initial wave packets, and combinations of ac and dc electric fields, he numerically solves the time-dependent Schroedinger equation. In the case of ideal periodic superlattice potentials, he investigates a long list of dynamical phenomena involving multiple miniband transitions and time-dependent electric fields. These include acceleration effects associated with interminiband transitions in strong fields, Zener resonances between minibands, dynamic localization with ac fields, increased single-miniband transport with an auxiliary resonant ac field, and enhanced or suppressed interminiband probability exchange using an auxiliary ac field. For all of the cases studied, the resulting time-dependent wave function is analyzed by projecting the data onto convenient orthonormal bases. This allows a detailed comparison with approximately analytic treatments. In an effort to explain the rapid decay of experimentally measured Bloch oscillation (BO) signals the author incorporates a one-dimensional representation of interface roughness (IR) into their superlattice potential. He shows that as a result of IR, the electron dynamics can be characterized in terms of many discrete, incommensurate frequencies near the Block frequency. Chapters 2, 3, 4 and 5 have been removed from this report and will be processed separately.

  3. Effects of electric field methods on modeling the midlatitude ionospheric electrodynamics and inner magnetosphere dynamics

    Science.gov (United States)

    Yu, Yiqun; Jordanova, Vania K.; Ridley, Aaron J.; Toth, Gabor; Heelis, Roderick

    2017-05-01

    We report a self-consistent electric field coupling between the midlatitude ionospheric electrodynamics and inner magnetosphere dynamics represented in a kinetic ring current model. This implementation in the model features another self-consistency in addition to its already existing self-consistent magnetic field coupling with plasma. The model is therefore named as Ring current-Atmosphere interaction Model with Self-Consistent magnetic (B) and electric (E) fields, or RAM-SCB-E. With this new model, we explore, by comparing with previously employed empirical Weimer potential, the impact of using self-consistent electric fields on the modeling of storm time global electric potential distribution, plasma sheet particle injection, and the subauroral polarization streams (SAPS) which heavily rely on the coupled interplay between the inner magnetosphere and midlatitude ionosphere. We find the following phenomena in the self-consistent model: (1) The spatially localized enhancement of electric field is produced within 2.5 electric potential contours show more substantial skewing toward the postmidnight than the Weimer potential, suggesting the resistance on the particles from directly injecting toward the low-L region. (3) The proton flux indeed indicates that the plasma sheet inner boundary at the dusk-premidnight sector is located further away from the Earth than in the Weimer potential, and a "tongue" of low-energy protons extends eastward toward the dawn, leading to the Harang reversal. (4) SAPS are reproduced in the subauroral region, and their magnitude and latitudinal width are in reasonable agreement with data.

  4. Application of Computer Systems of Dynamic Modeling for Evaluation of Protection Behavior of Electric Power Lines

    Directory of Open Access Journals (Sweden)

    F. A. Romaniouk

    2008-01-01

    Full Text Available The paper considers problems pertaining to mathematical modeling of a transformer substation with protected electric power lines. It is proposed to use systems of dynamic modeling for investigations applying a method of calculative experiment with the purpose to evaluate behavior of protection and automation at short circuits. The paper contains comparison of results obtained with the help of program-simulated complex on the basis of a complex mathematical model of an object and with the help of dynamic modeling system – MathLab.

  5. Dynamic characteristics of non-ideal plasmas in an external high frequency electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adamyan, V M [Department of Theoretical Physics, I. I. Mechnikov Odessa National University, 65026 Odessa (Ukraine); Djuric, Z [Silvaco Data System, Silvaco Technology Centre, Compass Point, St. Ives PE27 5JL (United Kingdom); Mihajlov, A A [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Sakan, N M [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Tkachenko, I M [Department of Applied Mathematics, ETSII, Polytechnic University of Valencia, Camino de Vera s/n, Valencia 46022 (Spain)

    2004-07-21

    The dynamic electric conductivity, dielectric permeability and refraction and reflection coefficients of a completely ionized gaseous plasma in a high frequency (HF) external electric field are calculated. These results are obtained within the self-consistent field approach developed earlier for the static conductivity determination. The plasma electron density, N{sub e}, and temperature, T, varied within the following limits: 10{sup 19} {<=} N{sub e} {<=} 10{sup 21} cm{sup -3} and 2 x 10{sup 4} {<=} T {<=} 10{sup 6} K, respectively. The external electric field frequency, f, varied in the range 3 GHz{<=} f {<=} 0.05{omicron}{sub p}, where {omicron}{sub p} is the circular plasma frequency. Thus, the upper limit for f is either in the microwave or in the far infrared frequency band. The final results are shown in a parameterized form, suitable for laboratory applications.

  6. The Impact of Dynamic Electricity Tariff on Long-run Incremental Cost

    DEFF Research Database (Denmark)

    Ding, Yi; Li, Yang; Pineda, Salvador

    2012-01-01

    infrastructure needs to be made in order to cope with this tremendous change in an efficient and effective manner. Long-run incremental cost (LRIC) pricing method is recognized as an economically efficient approach for pricing network charges, which provides forward-looking information for future investment cost......Electricity plays an important role in the future energy framework around the world. The foreseen high penetration of renewable energy resources and electric vehicles (EV) will change the way of understanding and operating power systems. Consequently, significant investment in network....... LRIC evaluation is usually conducted on the basis that demand is passive and uncontrollable. The impact of demand flexibility on LRIC has not been comprehensively studied. In this paper, the effect of dynamic electricity tariff and flexible demand on LRIC and network investment decisions is deeply...

  7. An empirically constructed dynamic electric dipole polarizability function of magnesium and its applications

    CERN Document Server

    Babb, James F

    2015-01-01

    The dynamic electric dipole polarizability function for the magnesium atom is formed by assembling the atomic electric dipole oscillator strength distribution from combinations of theoretical and experimental data for resonance oscillator strengths and for photoionization cross sections of valence and inner shell electrons. Consistency with the oscillator strength (Thomas-Reiche-Kuhn) sum rule requires the adopted principal resonance line oscillator strength to be several percent lower than the values given in two critical tabulations, though the value adopted is consistent with a number of theoretical determinations. The static polarizability is evaluated. Comparing the resulting dynamic polarizability as a function of photon energy with more elaborate calculations reveals the contributions of inner shell electron excitations. The present results are applied to calculate the long-range interactions between two and three magnesium atoms and the interaction between a magnesium atom and a perfectly conducting m...

  8. Dynamic Range Enhancement of High-Speed Electrical Signal Data via Non-Linear Compression

    Science.gov (United States)

    Laun, Matthew C. (Inventor)

    2016-01-01

    Systems and methods for high-speed compression of dynamic electrical signal waveforms to extend the measuring capabilities of conventional measuring devices such as oscilloscopes and high-speed data acquisition systems are discussed. Transfer function components and algorithmic transfer functions can be used to accurately measure signals that are within the frequency bandwidth but beyond the voltage range and voltage resolution capabilities of the measuring device.

  9. Dynamic Modeling and Simulation of Deep Geothermal Electric Submersible Pumping Systems

    OpenAIRE

    Julian Kullick; Hackl, Christoph M.

    2017-01-01

    Deep geothermal energy systems employ electric submersible pumps (ESPs) in order to lift geothermal fluid from the production well to the surface. However, rough downhole conditions and high flow rates impose heavy strain on the components, leading to frequent failures of the pump system. As downhole sensor data is limited and often unrealible, a detailed and dynamical model system will serve as basis for deeper understanding and analysis of the overall system behavior. Furthermore, it allows...

  10. Tunable superlattice amplifiers based on dynamics of miniband electrons in electric and magnetic fields

    OpenAIRE

    Hyart, T. (Timo)

    2009-01-01

    Abstract The most important paradigms in quantum mechanics are probably a twolevel system, a harmonic oscillator and an ideal (infinite) periodic potential. The first two provide a starting point for understanding the phenomena in systems where the spectrum of energy levels is discrete, whereas the last one results in continuous energy bands. Here an attempt is made to study the dynamics of the electrons in a narrow miniband of a semiconductor superlattice under electric and magnetic field...

  11. Dynamic imaging in electrical impedance tomography of the human chest with online transition matrix identification.

    Science.gov (United States)

    Moura, Fernando Silva; Aya, Julio Cesar Ceballos; Fleury, Agenor Toledo; Amato, Marcelo Britto Passos; Lima, Raul Gonzalez

    2010-02-01

    One of the electrical impedance tomography objectives is to estimate the electrical resistivity distribution in a domain based only on electrical potential measurements at its boundary generated by an imposed electrical current distribution into the boundary. One of the methods used in dynamic estimation is the Kalman filter. In biomedical applications, the random walk model is frequently used as evolution model and, under this conditions, poor tracking ability of the extended Kalman filter (EKF) is achieved. An analytically developed evolution model is not feasible at this moment. The paper investigates the identification of the evolution model in parallel to the EKF and updating the evolution model with certain periodicity. The evolution model transition matrix is identified using the history of the estimated resistivity distribution obtained by a sensitivity matrix based algorithm and a Newton-Raphson algorithm. To numerically identify the linear evolution model, the Ibrahim time-domain method is used. The investigation is performed by numerical simulations of a domain with time-varying resistivity and by experimental data collected from the boundary of a human chest during normal breathing. The obtained dynamic resistivity values lie within the expected values for the tissues of a human chest. The EKF results suggest that the tracking ability is significantly improved with this approach.

  12. Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.

    Directory of Open Access Journals (Sweden)

    Mingying Huo

    Full Text Available The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail.

  13. Coupled attitude-orbit dynamics and control for an electric sail in a heliocentric transfer mission.

    Science.gov (United States)

    Huo, Mingying; Zhao, Jun; Xie, Shaobiao; Qi, Naiming

    2015-01-01

    The paper discusses the coupled attitude-orbit dynamics and control of an electric-sail-based spacecraft in a heliocentric transfer mission. The mathematical model characterizing the propulsive thrust is first described as a function of the orbital radius and the sail angle. Since the solar wind dynamic pressure acceleration is induced by the sail attitude, the orbital and attitude dynamics of electric sails are coupled, and are discussed together. Based on the coupled equations, the flight control is investigated, wherein the orbital control is studied in an optimal framework via a hybrid optimization method and the attitude controller is designed based on feedback linearization control. To verify the effectiveness of the proposed control strategy, a transfer problem from Earth to Mars is considered. The numerical results show that the proposed strategy can control the coupled system very well, and a small control torque can control both the attitude and orbit. The study in this paper will contribute to the theory study and application of electric sail.

  14. Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Lehikoinen, A.; Huttunen, J.M.J.; Finsterle, S.; Kowalsky, M.B.; Kaipio, J.P.

    2009-08-01

    We propose an approach for imaging the dynamics of complex hydrological processes. The evolution of electrically conductive fluids in porous media is imaged using time-lapse electrical resistance tomography. The related dynamic inversion problem is solved using Bayesian filtering techniques, that is, it is formulated as a sequential state estimation problem in which the target is an evolving posterior probability density of the system state. The dynamical inversion framework is based on the state space representation of the system, which involves the construction of a stochastic evolution model and an observation model. The observation model used in this paper consists of the complete electrode model for ERT, with Archie's law relating saturations to electrical conductivity. The evolution model is an approximate model for simulating flow through partially saturated porous media. Unavoidable modeling and approximation errors in both the observation and evolution models are considered by computing approximate statistics for these errors. These models are then included in the construction of the posterior probability density of the estimated system state. This approximation error method allows the use of approximate - and therefore computationally efficient - observation and evolution models in the Bayesian filtering. We consider a synthetic example and show that the incorporation of an explicit model for the model uncertainties in the state space representation can yield better estimates than a frame-by-frame imaging approach.

  15. Dynamic Self-Adaptive Reliability Control for Electric-Hydraulic Systems

    Directory of Open Access Journals (Sweden)

    Yi Wan

    2015-02-01

    Full Text Available The high-speed electric-hydraulic proportional control is a new development of the hydraulic control technique with high reliability, low cost, efficient energy, and easy maintenance; it is widely used in industrial manufacturing and production. However, there are still some unresolved challenges, the most notable being the requirements of high stability and real-time by the classical control algorithm due to its high nonlinear characteristics. We propose a dynamic self-adaptive mixed control method based on the least squares support vector machine (LSSVM and the genetic algorithm for high-speed electric-hydraulic proportional control systems in this paper; LSSVM is used to identify and adjust online a nonlinear electric-hydraulic proportional system, and the genetic algorithm is used to optimize the control law of the controlled system and dynamic self-adaptive internal model control and predictive control are implemented by using the mixed intelligent method. The internal model and the inverse control model are online adjusted together. At the same time, a time-dependent Hankel matrix is constructed based on sample data; thus finite dimensional solution can be optimized on finite dimensional space. The results of simulation experiments show that the dynamic characteristics are greatly improved by the mixed intelligent control strategy, and good tracking and high stability are met in condition of high frequency response.

  16. RESEARCH OF DYNAMIC PARAMETERS OF THE ELECTRIC DRIVE ON THE BASIS OF ROLLING ROTOR MOTOR

    Directory of Open Access Journals (Sweden)

    G. V. Kulinchenko

    2016-12-01

    Full Text Available Purpose. Development and investigation of a dynamic model of electric drive on the base of the rolling rotor motor (RRM which reflects the positioning of the actuator of the locking and regulating equipment in time. Methodology. Analytical description of electromagnetic and mechanical processes in the electric drive during the RRM shaft movement by using a system of differential equations. Numerical imitation modeling with the processes visualization in the Matlab environment of the RRM rotor displacement with mechanical load in time. Results. It is shown that the degree of influence of the value of the load inertia on the dynamics of the object obtained by the waveform changes the rotation angle of the rotor and motor speed in time. The degree of influence of the value of the electromagnetic time constant of the dynamics of the positioning of the actuator, and the nature of transients during acceleration and fixing position of the rotor with a predetermined moment of inertia for different values of inductance. The effect of the ratio of electromechanical and electromagnetic time constants of the nature of the transition processes accompanying jog mode angular displacement of the drive shaft on the base of RRM. Originality. The lack of technical means to ensure acceptable accuracy time measurement of angular displacement shaft of the actuator in jog mode offset by using a laser meter which gives the opportunity to assess the adequacy of the dynamic model of the RRM. Practical value. The results of investigations allow to create a tool for optimization of structural, technical and hardware and software solutions for the improvement and modernization of the projected electric locking and regulating equipment. The direction for improving the dynamics of the drive on the basis of RRM is indicated providing for an increase in its torque characteristics of the motor by reducing the influence of the parameters of transients.

  17. Powertrain dynamics and control of a two speed dual clutch transmission for electric vehicles

    Science.gov (United States)

    Walker, Paul; Zhu, Bo; Zhang, Nong

    2017-02-01

    The purpose of this paper is to demonstrate the application of torque based powertrain control for multi-speed power shifting capable electric vehicles. To do so simulation and experimental studies of the shift transient behaviour of dual clutch transmission equipped electric vehicle powertrains is undertaken. To that end a series of power-on and power-off shift control strategies are then developed for both up and down gear shifts, taking note of the friction load requirements to maintain positive driving load for power-on shifting. A mathematical model of an electric vehicle powertrain is developed including a DC equivalent circuit model for the electric machine and multi-body dynamic model of the powertrain system is then developed and integrated with a hydraulic clutch control system model. Integral control of the powertrain is then performed through simulations on the develop powertrain system model for each of the four shift cases. These simulation results are then replicated on a full scale powertrain test rig. To evaluate the performance of results shift duration and vehicle jerk are used as metrics to demonstrate that the presented strategies are effective for shift control in electric vehicles. Qualitative comparison of both theoretical and experimental results demonstrates reasonable agreement between simulated and experimental outcomes.

  18. Dynamic Modeling and Simulation on a Hybrid Power System for Electric Vehicle Applications

    Directory of Open Access Journals (Sweden)

    Hong-Wen He

    2010-11-01

    Full Text Available Hybrid power systems, formed by combining high-energy-density batteries and high-power-density ultracapacitors in appropriate ways, provide high-performance and high-efficiency power systems for electric vehicle applications. This paper first establishes dynamic models for the ultracapacitor, the battery and a passive hybrid power system, and then based on the dynamic models a comparative simulation between a battery only power system and the proposed hybrid power system was done under the UDDS (Urban Dynamometer Driving Schedule. The simulation results showed that the hybrid power system could greatly optimize and improve the efficiency of the batteries and their dynamic current was also decreased due to the participation of the ultracapacitors, which would have a good influence on batteries’ cycle life. Finally, the parameter matching for the passive hybrid power system was studied by simulation and comparisons.

  19. Dynamic parameter identification of robot arms with servo-controlled electrical motors

    Science.gov (United States)

    Jiang, Zhao-Hui; Senda, Hiroshi

    2005-12-01

    This paper addresses the issue of dynamic parameter identification of the robot manipulator with servo-controlled electrical motors. An assumption is made that all kinematical parameters, such as link lengths, are known, and only dynamic parameters containing mass, moment of inertia, and their functions need to be identified. First, we derive dynamics of the robot arm with a linear form of the unknown dynamic parameters by taking dynamic characteristics of the motor and servo unit into consideration. Then, we implement the parameter identification approach to identify the unknown parameters with respect to individual link separately. A pseudo-inverse matrix is used for formulation of the parameter identification. The optimal solution is guaranteed in a sense of least-squares of the mean errors. A Direct Drive (DD) SCARA type industrial robot arm AdeptOne is used as an application example of the parameter identification. Simulations and experiments for both open loop and close loop controls are carried out. Comparison of the results confirms the correctness and usefulness of the parameter identification and the derived dynamic model.

  20. Dynamic Coordinated Shifting Control of Automated Mechanical Transmissions without a Clutch in a Plug-In Hybrid Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Xinlei Liu

    2012-08-01

    Full Text Available On the basis of the shifting process of automated mechanical transmissions (AMTs for traditional hybrid electric vehicles (HEVs, and by combining the features of electric machines with fast response speed, the dynamic model of the hybrid electric AMT vehicle powertrain is built up, the dynamic characteristics of each phase of shifting process are analyzed, and a control strategy in which torque and speed of the engine and electric machine are coordinatively controlled to achieve AMT shifting control for a plug-in hybrid electric vehicle (PHEV without clutch is proposed. In the shifting process, the engine and electric machine are well controlled, and the shift jerk and power interruption and restoration time are reduced. Simulation and real car test results show that the proposed control strategy can more efficiently improve the shift quality for PHEVs equipped with AMTs.

  1. Electrical synapses between AII amacrine cells: dynamic range and functional consequences of variation in junctional conductance.

    Science.gov (United States)

    Veruki, Margaret Lin; Oltedal, Leif; Hartveit, Espen

    2008-12-01

    AII amacrine cells form a network of electrically coupled interneurons in the mammalian retina and tracer coupling studies suggest that the junctional conductance (G(j)) can be modulated. However, the dynamic range of G(j) and the functional consequences of varying G(j) over the dynamic range are unknown. Here we use whole cell recordings from pairs of coupled AII amacrine cells in rat retinal slices to provide direct evidence for physiological modulation of G(j), appearing as a time-dependent increase from about 500 pS to a maximum of about 3,000 pS after 30-90 min of recording. The increase occurred in recordings with low- but not high-resistance pipettes, suggesting that it was related to intracellular washout and perturbation of a modulatory system. Computer simulations of a network of electrically coupled cells verified that our recordings were able to detect and quantify changes in G(j) over a large range. Dynamic-clamp electrophysiology, with insertion of electrical synapses between AII amacrine cells, allowed us to finely and reversibly control G(j) within the same range observed for physiologically coupled cells and to examine the quantitative relationship between G(j) and steady-state coupling coefficient, synchronization of subthreshold membrane potential fluctuations, synchronization and transmission of action potentials, and low-pass filter characteristics. The range of G(j) values over which signal transmission was modulated depended strongly on the specific functional parameter examined, with the largest range observed for action potential transmission and synchronization, suggesting that the full range of G(j) values observed during spontaneous run-up of coupling could represent a physiologically relevant dynamic range.

  2. A molecular dynamics study of nanoconfined water flow driven by rotating electric fields under realistic experimental conditions

    DEFF Research Database (Denmark)

    De Luca, Sergio; Todd, Billy; Hansen, Jesper Schmidt

    2014-01-01

    In our recent work, J. Chem. Phys. 2013, 138, 154712, we demonstrated the feasibility of unidirectional pumping of water, exploiting translational–rotational momentum coupling using nonequilibrium molecular dynamics simulations. Flow can be sustained when the fluid is driven out of equilibrium...... nonequilibrium molecular dynamics and analytical solutions of the extended Navier–Stokes equations, including an external rotating electric field has been performed, showing excellent agreement when the electric field parameters match the aforementioned small energy dissipation region...

  3. Modulating protein behaviors on responsive surface by external electric fields: A molecular dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Yun, E-mail: xieyunxx@gdpu.edu.cn; Pan, Yufang; Zhang, Rong; Liang, Ying; Li, Zhanchao

    2015-01-30

    Graphical abstract: The adsorption of Cyt c on phosphorylcholine self-assembled monolayers (N atoms of the choline groups are colored in blue while the P atoms of the phosphate groups in orange). - Highlights: • PC-SAM could sensitively adjust its charge distribution to applied electric fields. • Adsorption of Cyt c on the PC-SAM is promoted or retarded as the charge distribution of the SAM changes. • Orientations of Cyt c on the PC-SAM are regulated by the structural changes of the SAM. • The structural changes of the SAM cause little deformation in Cyt c. - Abstract: Molecular dynamics simulations were employed to investigate the modulation of protein behaviors on the electrically responsive zwitterionic phosphorylcholine self-assembled monolayers (PC-SAMs). Results show that PC-SAMs could sensitively respond to the applied electric fields and exhibit three states with different charge distributions, namely both the negatively charged phosphate groups and the positively charged choline groups are exposed to the solution in the absence of electric fields (state 1), phosphate groups exposed in the presence of positive electric fields (state 2), and choline groups exposed in the presence of negative electric fields (state 3). Under state 1, the adsorption of Cyt c on the PC-SAM is reversible and the orientations of Cyt c are randomly distributed. Under state 2, the adsorption of Cyt c is enhanced due to the electrostatic attractions between the exposed phosphate groups and the positively charged protein; when adsorbed on the PC-SAMs, Cyt c tends to adopt the orientation with the heme plane perpendicular to the surface plane, and the percentage of this orientation increases as the field strength rises up. Under state 3, the adsorption of Cyt c is retarded because of the electrostatic repulsions between the exposed choline groups and the protein; however, if the gaps between PC chains are large enough, Cyt c could insert into the PC-SAM and access the

  4. SAInt – A novel quasi-dynamic model for assessing security of supply in coupled gas and electricity transmission networks

    NARCIS (Netherlands)

    Pambour, Kwabena Addo; Cakir Erdener, Burcin; Bolado-Lavin, Ricardo; Dijkema, Gerhard P.J.

    2017-01-01

    The integration of renewable energy sources into existing electric power systems is connected with an increased interdependence between natural gas and electricity transmission networks. To analyse this interdependence and its impact on security of supply, we developed a novel quasi-dynamic

  5. Dynamic EROI Assessment of the IPCC 21st Century Electricity Production Scenario

    Directory of Open Access Journals (Sweden)

    Charles Neumeyer

    2016-04-01

    Full Text Available The Energy Return on Investment (EROI is an important measure of the energy gain of an electrical power generating facility that is typically evaluated based on the life cycle energy balance of a single facility. The EROI concept can be extended to cover a collection of facilities that comprise a complete power system and used to assess the expansion and evolution of a power system as it transitions from one portfolio mix of technologies to another over time. In this study we develop a dynamic EROI model that simulates the evolution of a power system and we perform an EROI simulation of one of the electricity production scenarios developed under the auspices of the Intergovernmental Panel on Climate Change (IPCC covering the global supply of electricity in the 21st century. Our analytic tool provides the means for evaluation of dynamic EROI based on arbitrary time-dependent demand scenarios by modeling the required expansion of power generation, including the plowback needed for new construction and to replace facilities as they are retired. The results provide insight into the level of installed and delivered power, above and beyond basic consumer demand, that is required to support construction during expansion, as well as the supplementary power that may be required if plowback constraints are imposed. In addition, sensitivity to EROI parameters, and the impact of energy storage efficiency are addressed.

  6. Charge-based separation of proteins and peptides by electrically induced dynamic pH profiles.

    Science.gov (United States)

    Brod, E; S Ben-Yosef, V; Bandhakavi, S; Sivan, U

    2016-01-29

    A new method for generating complex, dynamic pH profiles in an ampholyte-free separation channel is presented together with the theory behind its operation. The pH is modulated by an array of proton and hydroxide ion injectors placed along the separation channel. The ions generated in-situ by electrically driven water splitting across a bipolar membrane are injected to the channel in the presence of a longitudinal electric field, leading to the formation of a multi-step pH profile. Real-time control over the pH profile along the channel facilitates new dynamic separation strategies as well as steering and harvesting of focused molecules, which are both impossible with conventional separation methods. These freedoms are particularly attractive for Lab-on-a-Chip applications. The pH step-like profile alleviates one of the main hurdles of conventional isoelectric separation methods, namely, the slowing down of focused molecules as they approach their focusing spot. As a result, separation is completed within minutes for both peptides and proteins, even with low applied electric fields. We demonstrate protein and peptide separation within minutes, and resolution of ΔpI=0.2. Novel separation strategies based on spatio-temporal pH control are demonstrated as well. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Dynamic impedance model of the skin-electrode interface for transcutaneous electrical stimulation.

    Directory of Open Access Journals (Sweden)

    José Luis Vargas Luna

    Full Text Available Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through electrodes attached on the skin. For these applications, the electrode-skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting electrode-skin impedance can be simple extended to other stimulation waveforms and electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes.

  8. Effects of Thought Suppression on Provoked Men's Alcohol-Related Physical Aggression in the Laboratory.

    Science.gov (United States)

    Gallagher, Kathryn E; Lisco, Claire G; Parrott, Dominic J; Giancola, Peter R

    2014-01-01

    This study utilized a comprehensive theoretical approach to provide the first data on the impact of thought suppression on provoked men's alcohol-related aggression. A diverse community sample (58% African-American) of males between the ages of 21 and 35 (M = 25.25) were randomly assigned to one of two beverage conditions (i.e., alcohol, no-alcohol control). Following beverage consumption, participants were provoked via reception of electric shocks and a verbal insult from a fictitious male opponent. Participants' physical aggression was measured using a shock-based aggression task. Results indicated that acute alcohol intoxication significantly increased physical aggression among lower, but not higher, thought suppressing men. Results suggest that, under conditions of interpersonal provocation, alcohol intoxication produces a myopic focus on hostile thoughts and angry affect in lower, but not higher, suppression men. This pattern of results provides support for the durability of the alcohol myopia effect and highlights the need for continued examination of alcohol's role in the disruption of protective factors for men's aggression. It is important for research to continue to identify modifiable cognitive variables that influence self-regulation of behavior; however, it is imperative that researchers consider the extent to which these variables withstand alcohol's effects.

  9. The Dynamics of Oblate Drop Between Heterogeneous Plates Under Alternating Electric Field - Non-uniform Field

    Science.gov (United States)

    Kashina, M. A.; Alabuzhev, A. A.

    2017-12-01

    The dynamics of the incompressible fluid drop under the non-uniform electric field are considered. The drop is bounded axially by two parallel solid planes and the case of heterogeneous plates is investigated. The external electric field acts as an external force that causes motion of the contact line. We assume that the electric current is alternative current and the AC filed amplitude is a spatially non-uniform function. In equilibrium, the drop has the form of a circular cylinder. The equilibrium contact angle is 0.5π. In order to describe this contact line motion the modified Hocking boundary condition is applied: the velocity of the contact line is proportional to the deviation of the contact angle and the speed of the fast relaxation processes, which frequency is proportional to twice the frequency of the electric field. The Hocking parameter depends on the polar angle, i.e. the coefficient of the interaction between the plate and the fluid (the contact line) is a function of the plane coordinates. This function is expanded in a series of the Laplace operator eigenfunctions.

  10. Dynamic electrophoretic mobility and electric permittivity of concentrated suspensions of plate-like gibbsite particles.

    Science.gov (United States)

    Ahualli, S; González, M A; Delgado, A V; Jiménez, M L

    2017-09-15

    In this paper we present experimental results on the electrokinetic behavior of planar gibbsite particles in concentrated suspensions. The dc electrophoretic mobility measurements are in this case of little significance, as they are scarcely informative. In the present investigation, we show that the dielectric dispersion and dynamic electrophoresis can in contrast provide such information. The complicating factors are of course the non-spherical shape and the finite particle concentration, as no complete theory of these phenomena exists for such systems. We propose to use first of all a model of dynamic electrophoresis of spheroids in which the effect of volume fraction is considered by means of an approximate theory previously obtained for spheres, based on the evaluation of electrical and hydrodynamic interactions between particles. In addition, the role of volume fraction on the high frequency inertial relaxation is also ascertained and used to obtain a volume fraction-independent radius of the gibbsite spheroids. A similar approach is used for the evaluation of dielectric dispersion data. Both the dynamic mobility and dielectric constant dependencies on frequency were obtained for gibbsite suspensions of different volume fractions in 0.5mMKCl. The theoretical treatments elaborated were applied to these data, and a coherent picture of the geometrical and electrical characteristics of the particles was obtained. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Electric field control of magnon-induced magnetization dynamics in multiferroics

    Science.gov (United States)

    Risinggård, Vetle; Kulagina, Iryna; Linder, Jacob

    2016-01-01

    We consider theoretically the effect of an inhomogeneous magnetoelectric coupling on the magnon-induced dynamics of a ferromagnet. The magnon-mediated magnetoelectric torque affects both the homogeneous magnetization and magnon-driven domain wall motion. In the domains, we predict a reorientation of the magnetization, controllable by the applied electric field, which is almost an order of magnitude larger than that observed in other physical systems via the same mechanism. The applied electric field can also be used to tune the domain wall speed and direction of motion in a linear fashion, producing domain wall velocities several times the zero field velocity. These results show that multiferroic systems offer a promising arena to achieve low-dissipation magnetization rotation and domain wall motion by exciting spin-waves. PMID:27554064

  12. Dynamic conductivity of symmetric three-barrier plane nanosystem in constant electric field

    Directory of Open Access Journals (Sweden)

    O. Voitsekhivska

    2011-03-01

    Full Text Available The theory of dynamic conductivity of nanosystem is developed within the model of rectangular potentials and different effective masses of electron in open three-barrier resonance-tunnel structure in a constant homogeneous electric field. The application of this theory for the improvement of operating characteristics of quantum cascade laser active region (for the experimentally investigated In0.53Ga0.47As/In0.52Al0.48As heterosystem proves that for a certain geometric design of nanosystem there exists such minimal magnitude of constant electric field intensity, at which the electromagnetic field radiation power together with the density of current flowing through the separate cascade of quantum laser becomes maximal.

  13. Dynamic Modeling and Control Strategy Optimization for a Hybrid Electric Tracked Vehicle

    Directory of Open Access Journals (Sweden)

    Hong Wang

    2015-01-01

    Full Text Available A new hybrid electric tracked bulldozer composed of an engine generator, two driving motors, and an ultracapacitor is put forward, which can provide high efficiencies and less fuel consumption comparing with traditional ones. This paper first presents the terramechanics of this hybrid electric tracked bulldozer. The driving dynamics for this tracked bulldozer is then analyzed. After that, based on analyzing the working characteristics of the engine, generator, and driving motors, the power train system model and control strategy optimization is established by using MATLAB/Simulink and OPTIMUS software. Simulation is performed under a representative working condition, and the results demonstrate that fuel economy of the HETV can be significantly improved.

  14. Semiparametric Identification of Human Arm Dynamics for Flexible Control of a Functional Electrical Stimulation Neuroprosthesis.

    Science.gov (United States)

    Schearer, Eric M; Liao, Yu-Wei; Perreault, Eric J; Tresch, Matthew C; Memberg, William D; Kirsch, Robert F; Lynch, Kevin M

    2016-12-01

    We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory.

  15. Dynamic Optimal Energy Flow in the Integrated Natural Gas and Electrical Power Systems

    DEFF Research Database (Denmark)

    Fang, Jiakun; Zeng, Qing; Ai, Xiaomeng

    2018-01-01

    This work focuses on the optimal operation of the integrated gas and electrical power system with bi-directional energy conversion. Considering the different response times of the gas and power systems, the transient gas flow and steady- state power flow are combined to formulate the dynamic....... Simulation on the test case illustrates the success of the modelling and the beneficial roles of the power-to-gas are analyzed. The proposed model can be used in the decision support for both planning and operation of the coordinated natural gas and electrical power systems....... optimal energy flow in the integrated gas and power systems. With proper assumptions and simplifications, the problem is transformed into a single stage linear programming. And only a single stage linear programming is needed to obtain the optimal operation strategy for both gas and power systems...

  16. Dynamical characteristics of Rydberg electrons released by a weak electric field

    CERN Document Server

    Diesen, Elias; Richter, Martin; Kunitski, Maksim; Dörner, Reinhard; Rost, Jan M

    2015-01-01

    The dynamics of ultra-slow electrons in the combined potential of an ionic core and a static electric field is discussed. With state-of-the-art detection it is possible to create such electrons through strong intense-field photo-absorption and to detect them via high-resolution time-of-flight spectroscopy despite their very low kinetic energy. The characteristic feature of their momentum spectrum, which emerges at the same position for different laser orientations, is derived and could be revealed experimentally with an energy resolution of the order of 1meV.

  17. Simulation of Dynamic Regimes in Asynchronous Traction Electric Drives of Locomotives

    Directory of Open Access Journals (Sweden)

    P. O. Seyidov

    2011-01-01

    Full Text Available The paper considers a dynamic model for locomotive electric drive with four asynchronous traction motors and their stator windings are serially connected. A mathematical model for motors being fed by one autonomous inverter has been developed in the paper. Serial connection makes it possible to increase a value of the total supply voltage. An analysis of the developed model shows that currents consumed by motors with their serial connection are lower in case of their parallel operation.  Direct and frequency start-up curves are given on the basis of the developed model.

  18. A Dynamic Behaviour Analysis on the Frequency Control Capability of Electric Vehicles

    DEFF Research Database (Denmark)

    Zarogiannis, Athanasios; Marinelli, Mattia; Træholt, Chresten

    2014-01-01

    The paper presents results of a study on the dynamic response of Electric Vehicle’s (EV) when participating in frequency control of an islanded system. The following cases were considered: when there is no EV performing frequency control, when the EV participates in primary frequency control...... and when the EV participates in both primary and secondary frequency control. Different parameters are tested in various combinations, and their influence on frequency deviation as well as power and energy provided by the EV with vehicle-to-grid (V2G) capability is shown....

  19. Do stages of dentistry training affect anxiety provoking situations?

    Science.gov (United States)

    Obarisiagbon, A; Azodo, Cc; Omoaregba, Jo; James, Bo

    2014-11-01

    Undetected and unaddressed anxiety negatively affects performance in clinical learning environments. The aim was to investigate the anxiety provoking situations in clinical dental care delivery among students of preclinical and clinical years and house officers. A 38-item modified Moss and McManus clinical anxiety questionnaire, general health questionnaire-12 (GHQ-12) and the Zung self-rating anxiety scale were the data collection tools. Of the 84 recruited, 79 completed the study giving 94.0% (79/84) response rate. The median age of the participants was 25 years with 50.6% (40/79) being 20-25 years. Gender distribution revealed that males constituted 60.8% (48/79) of the participants. House officers constituted 29.1% (23/79), clinical students 36.7% (29/79), and preclinical students 34.2 (27/79) of the participants. The top anxiety provoking situations using the modified Moss and McManus clinical anxiety questionnaire were extracting wrong tooth 3.24 (1.06), inability to pass examination 3.32 (1.01), achieving examination requirement 3.19 (1.01), fracturing a tooth 3.08 (0.98) and accidental pulp exposure 2.96 (1.04). Getting diagnosis wrong, help in faint episode, not developing radiograph properly and coping with children were the anxiety provoking situations that showed statistically significant difference in the 3 studied training stages of dentistry. Bonferroni post-hoc analysis significant difference was in the preclinical and clinical students' pair for getting diagnosis wrong, not developing radiograph properly and coping with children while house officers/clinical students and house officers/preclinical students' pairs were for help in faint episode. Overall, 2.5% (2/79) had severe, 69.6% (55/79) moderate, 26.6% (21/79) mild clinical anxiety while 1 (1.3%) of the participants expressed no clinical anxiety. Data from this study revealed that the clinical anxiety of moderate severity was prevalent among the studied dental healthcare students. The anxiety-provoking

  20. Children's self-speech and self-regulation during a fear-provoking behavioral test.

    NARCIS (Netherlands)

    Prins, P.J.M.

    1986-01-01

    Conducted a behavioral test and a behavioral interview to assess children's spontaneous use of self-speech and self-regulation in a fear-provoking situation. 44 children (aged 8-12 yrs) performed a series of more fear-provoking (e.g., jumping off the high diving board) or less fear-provoking (e.g.,

  1. Integrated analysis of DFIG drive-train and power electronics dynamics during electrical AC faults and wind disturbances

    DEFF Research Database (Denmark)

    Barahona Garzón, Braulio; Sørensen, Poul Ejnar; Anaya-Lara, Olimpo

    2013-01-01

    The dynamics of a 2 MW DFIG wind turbine are studied during electrical AC faults, and wind disturbances. A simulation platform that couples HAWC2, and Matlab/Simulink was used. High frequencies of the gear box, and power electronics are neglected. It was shown that the dynamics of the dc...

  2. The dynamic and steady state behavior of a PEM fuel cell as an electric energy source

    Energy Technology Data Exchange (ETDEWEB)

    Costa, R.A. [Fundacao Educacional de Barretos (FEB), School of Electrical Engineering, Av. Prof. Roberto Frade Monte, 389 Aeroporto, 14783.226, Barretos, SP (Brazil); Camacho, J.R. [Universidade Federal de Uberlandia, School of Electrical Engineering, Rural Electricity and Alternative Energy Sources Lab., Av. Joao N. de Avila, 2121, 38400.902, Uberlandia, MG (Brazil)

    2006-10-27

    The main objective of this work is to extract information on the internal behavior of three small polymer electrolyte membrane fuel cells under static and dynamic load conditions. A computational model was developed using Scilab [SCILAB 4, Scilab-a free scientific software package, http://www.scilab.org/, INRIA, France, December, 2005] to simulate the static and dynamic performance [J.M. Correa, A.F. Farret, L.N. Canha, An analysis of the dynamic performance of proton exchange membrane fuel cells using an electrochemical model, in: 27th Annual Conference of IEEE Industrial Electronics Society, 2001, pp. 141-146] of this particular type of fuel cell. This dynamic model is based on electrochemical equations and takes into consideration most of the chemical and physical characteristics of the device in order to generate electric power. The model takes into consideration the operating, design parameters and physical material properties. The results show the internal losses and concentration effects behavior, which are of interest for power engineers and researchers. (author)

  3. Reconstructing three-dimensional reentrant cardiac electrical wave dynamics using data assimilation

    Science.gov (United States)

    Hoffman, M. J.; LaVigne, N. S.; Scorse, S. T.; Fenton, F. H.; Cherry, E. M.

    2016-01-01

    For many years, reentrant scroll waves have been predicted and studied as an underlying mechanism for cardiac arrhythmias using numerical techniques, and high-resolution mapping studies using fluorescence recordings from the surfaces of cardiac tissue preparations have confirmed the presence of visible spiral waves. However, assessing the three-dimensional dynamics of these reentrant waves using experimental techniques has been limited to verifying stable scroll-wave dynamics in relatively thin preparations. We propose a different approach to recovering the three-dimensional dynamics of reentrant waves in the heart. By applying techniques commonly used in weather forecasting, we combine dual-surface observations from a particular experiment with predictions from a numerical model to reconstruct the full three-dimensional time series of the experiment. Here, we use model-generated surrogate observations from a numerical experiment to evaluate the performance of the ensemble Kalman filter in reconstructing such time series for a discordant alternans state in one spatial dimension and for scroll waves in three dimensions. We show that our approach is able to recover time series of both observed and unobserved variables matching the truth. Where nearby observations are available, the error is reduced below the synthetic observation error, with a smaller reduction with increased distance from observations. Our findings demonstrate that state reconstruction for spatiotemporally complex cardiac electrical dynamics is possible and will lead naturally to applications using real experimental data.

  4. Electric-field-driven domain wall dynamics in perpendicularly magnetized multilayers

    Directory of Open Access Journals (Sweden)

    Diego López González

    2017-03-01

    Full Text Available We report on reversible electric-field-driven magnetic domain wall motion in a Cu/Ni multilayer on a ferroelectric BaTiO3 substrate. In our heterostructure, strain-coupling to ferroelastic domains with in-plane and perpendicular polarization in the BaTiO3 substrate causes the formation of domains with perpendicular and in-plane magnetic anisotropy, respectively, in the Cu/Ni multilayer. Walls that separate magnetic domains are elastically pinned onto ferroelectric domain walls. Using magneto-optical Kerr effect microscopy, we demonstrate that out-of-plane electric field pulses across the BaTiO3 substrate move the magnetic and ferroelectric domain walls in unison. Our experiments indicate an exponential increase of domain wall velocity with electric field strength and opposite domain wall motion for positive and negative field pulses. The application of a magnetic field does not affect the velocity of magnetic domain walls, but independently tailors their internal spin structure, causing a change in domain wall dynamics at high velocities.

  5. Conformational dynamics and aggregation behavior of piezoelectric diphenylalanine peptides in an external electric field.

    Science.gov (United States)

    Kelly, Catherine M; Northey, Thomas; Ryan, Kate; Brooks, Bernard R; Kholkin, Andrei L; Rodriguez, Brian J; Buchete, Nicolae-Viorel

    2015-01-01

    Aromatic peptides including diphenylalanine (FF) have the capacity to self-assemble into ordered, biocompatible nanostructures with piezoelectric properties relevant to a variety of biomedical applications. Electric fields are commonly applied to align FF nanotubes, yet little is known about the effect of the electric field on the assembly process. Using all-atom molecular dynamics with explicit water molecules, we examine the response of FF monomers to the application of a constant external electric field over a range of intensities. We probe the aggregation mechanism of FF peptides, and find that the presence of even relatively weak fields can accelerate ordered aggregation, primarily by facilitating the alignment of individual molecular dipole moments. This is modulated by the conformational response of individual FF peptides (e.g., backbone stretching) and by the cooperative alignment of neighboring FF and water molecules. These observations may facilitate future studies on the controlled formation of nanostructured aggregates of piezoelectric peptides and the understanding of their electro-mechanical properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Dynamics of Single-Photon Emission from Electrically Pumped Color Centers

    Science.gov (United States)

    Khramtsov, Igor A.; Agio, Mario; Fedyanin, Dmitry Yu.

    2017-08-01

    Low-power, high-speed, and bright electrically driven true single-photon sources, which are able to operate at room temperature, are vital for the practical realization of quantum-communication networks and optical quantum computations. Color centers in semiconductors are currently the best candidates; however, in spite of their intensive study in the past decade, the behavior of color centers in electrically controlled systems is poorly understood. Here we present a physical model and establish a theoretical approach to address single-photon emission dynamics of electrically pumped color centers, which interprets experimental results. We support our analysis with self-consistent numerical simulations of a single-photon emitting diode based on a single nitrogen-vacancy center in diamond and predict the second-order autocorrelation function and other emission characteristics. Our theoretical findings demonstrate remarkable agreement with the experimental results and pave the way to the understanding of single-electron and single-photon processes in semiconductors.

  7. Volcano electrical tomography unveils edifice collapse hazard linked to hydrothermal system structure and dynamics.

    Science.gov (United States)

    Rosas-Carbajal, Marina; Komorowski, Jean-Christophe; Nicollin, Florence; Gibert, Dominique

    2016-07-26

    Catastrophic collapses of the flanks of stratovolcanoes constitute a major hazard threatening numerous lives in many countries. Although many such collapses occurred following the ascent of magma to the surface, many are not associated with magmatic reawakening but are triggered by a combination of forcing agents such as pore-fluid pressurization and/or mechanical weakening of the volcanic edifice often located above a low-strength detachment plane. The volume of altered rock available for collapse, the dynamics of the hydrothermal fluid reservoir and the geometry of incipient collapse failure planes are key parameters for edifice stability analysis and modelling that remain essentially hidden to current volcano monitoring techniques. Here we derive a high-resolution, three-dimensional electrical conductivity model of the La Soufrière de Guadeloupe volcano from extensive electrical tomography data. We identify several highly conductive regions in the lava dome that are associated to fluid saturated host-rock and preferential flow of highly acid hot fluids within the dome. We interpret this model together with the existing wealth of geological and geochemical data on the volcano to demonstrate the influence of the hydrothermal system dynamics on the hazards associated to collapse-prone altered volcanic edifices.

  8. Simulation and Implementation of Sensorless Control in Multi-Motors Electric Drives with High Dynamics

    Directory of Open Access Journals (Sweden)

    Marcel Nicola

    2017-05-01

    Full Text Available In this article we’ll tackle the control of multi-motors electric drives with high dynamic, with rapid changes in torque and speed, with rigid or flexible coupling of motors, where the control strategy is FOC (Field Oriented Control for each drives and the distributed control in local network using the CANopen protocol. In the surface mining industry, from which the electric drive application for this article is selected, the general trend is toward using asynchronous motors with short-circuit rotor, due to the advantages of this motor both in terms of design and operation. In order to achieve the variable speed, must be used the static frequency converters with sensorless control, where speed is estimated using a Model References Adaptive Control Estimator. The global control system proposed in this paper contain this type of MRAC estimator together with PI-control based, who ensures a good dynamic performance but in a lower complexity of structure such that are properly to implement in real time in a distributed control system with DSP in local network using the CANopen protocol with advantages in terms of software technology, as well as control cost and flexibility of use. Following these directions a functional application was implemented and tested in practice.

  9. Dynamics of the Radial Electric Field in Toroidal Plasmas in the Plateau Regime

    Science.gov (United States)

    Yushmanov, P. N.; Lebedev, V. B.; Diamond, P. H.; Smolyakov, A. I.

    1996-11-01

    The equation describing the evolution of the radial electric field driven by small scale turbulence in toroidal plasmas in the plateau regime is derived. The dynamics of Er is governed by the poloidal variation of plasma pressure combined with the radial component of nabla B drifts as well as by the polarization and inertial radial currents. The poloidally dependent part of the ion distribution function is obtained from the time dependent solution of the Drift Kinetic Equation (DKE) in the presence of turbulence-induced external forces. These forces are created by the parallel inertia terms resulting from the small scale, turbulent fluctuations. The relaxation of Er occurs in the form of damped oscillations with the time scale of the order of ion transient time. In the plateau regime, collisions do not influence the Er dynamics except for the large values of safety factor, q, when a weakly damped branch of these oscillations with ω ~ q ωb = cs / R appears. For this branch ω / ωb > 1, the collisionless damping is exponentially small and the collisional damping γ ~ ν becomes important. The role of the time dependent radial electric field shear in tokamak plasmas is discussed.

  10. Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

    Science.gov (United States)

    Baidak, Y.; Smyk, V.

    2017-08-01

    Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

  11. The effect of conceptual change text structure on concept understanding and misconception reduction of dynamic electricity

    Directory of Open Access Journals (Sweden)

    Perdana Gde Parie

    2018-01-01

    Full Text Available This study investigated the effect of conceptual change text on student understanding and misconception reduction of dynamic electricity concept. A quasi-experimental research with pre-test/post-test non-equivalent control group design was used. The subjects for this study consisted of 90 tenth-grade students. The three-tier test, the Dynamic Electricity Concept Test (DECT, was developed as pre-test and post-test to access the student conceptions. While the experimental group (n=45 received a conceptual change text, the control group (n=45 received an expository text. MANCOVA analysis was used to know the effect of conceptual change text structure on both dependent variables. The results of the study indicated that the student in the experimental group showed significantly higher understanding and higher misconceptions reduction compared to the students in the control group. Both groups had increased concept understanding and misconceptions reduction, however, the experimental group’s result was better than the control group.

  12. Calculation of the neutron electric dipole moment with two dynamical flavors of domain wall fermions

    Energy Technology Data Exchange (ETDEWEB)

    F. Berruto; T. Blum; K. Orginos; A. Soni

    2005-12-08

    We present a study of the neutron electric dipole moment ({rvec d}{sub N}) within the framework of lattice QCD with two flavors of dynamical light quarks. The dipole moment is sensitive to the topological structure of the gauge fields, and accuracy can only be achieved by using dynamical, or sea quark, calculations. However, the topological charge evolves slowly in these calculations, leading to a relatively large uncertainty in {rvec d}{sub N}. It is shown, using quenched configurations, that a better sampling of the charge distribution reduces this problem, but because the CP even part of the fermion determinant is absent, both the topological charge distribution and {rvec d}{sub N} are pathological in the chiral limit. We discuss the statistical and systematic uncertainties arising from the topological charge distribution and unphysical size of the quark mass in our calculations and prospects for eliminating them. Our calculations employ the RBC collaboration two flavor domain wall fermion and DBW2 gauge action lattices with inverse lattice spacing a{sup -1} {approx} 1.7 GeV, physical volume V {approx} (2 fm){sup 3}, and light quark mass roughly equal to the strange quark mass (m{sub sea} = 0.03 and 0.04). We determine a value of the electric dipole moment that is zero within (statistical) errors, |{rvec d}{sub N}| = -0.04(20) e-{theta}-fm at the smaller sea quark mass. Satisfactory results for the magnetic and electric form factors of the proton and neutron are also obtained and presented.

  13. Velocity Modulation Laser Spectroscopy: a Probe of Ion Dynamics in Electrical Discharges.

    Science.gov (United States)

    Radunsky, Michael Benjamin

    A tunable dye laser absorption spectrometer was constructed and used to probe several dynamical properties of electrical discharges. These experiments permitted a characterization of velocity modulation detection of molecular ions. By measuring state distributions and the random and directed components of the velocity of the N _sp{2}{+} ion under various conditions, a model of the energy flux through the ion population in the discharge was constructed. Because of the low rate of vibrational energy transfer of the N _sp{2}{+} through collisions with the buffer gas, the vibrational energy is isolated from the translational and rotational energy. However, because of the positioning of the vibrational eigenstates in the first excited electronic state (A^2 Pi) relative to those of the ground state, the vibrational energy readily interconverts with the electronic excitation through collisions. The rotational and translational energy also readily interconvert and both processes becomes more facile as the pressure is increased. As the pressure of helium is increased to the maximum studied (11 Torr), the ion drift energy is almost completely randomized, whereas at low pressure (3 Torr), the directed translational energy exceeds the random component by a factor of three. The time dependence of absorption signals was observed for several different ions. Using a boxcar and signal averagers to process the data confirms that velocity modulation spectra do result from the Doppler shifting of ionic transitions into resonance with the laser. However, there is a contribution to the signal even when the axial electric field points in the "wrong" direction, accelerating the ions out of resonance with the laser. This contribution arises because the Doppler width of the transition is larger than the shift in transition frequency due to the electric field. These experiments also indicate that the axial electric field is square wave modulated, but that during part of the discharge cycle

  14. Exploring how extracellular electric field modulates neuron activity through dynamical analysis of a two-compartment neuron model.

    Science.gov (United States)

    Yi, Guo-Sheng; Wang, Jiang; Wei, Xi-Le; Tsang, Kai-Ming; Chan, Wai-Lok; Deng, Bin; Han, Chun-Xiao

    2014-06-01

    To investigate how extracellular electric field modulates neuron activity, a reduced two-compartment neuron model in the presence of electric field is introduced in this study. Depending on neuronal geometric and internal coupling parameters, the behaviors of the model have been studied extensively. The neuron model can exist in quiescent state or repetitive spiking state in response to electric field stimulus. Negative electric field mainly acts as inhibitory stimulus to the neuron, positive weak electric field could modulate spiking frequency and spike timing when the neuron is already active, and positive electric fields with sufficient intensity could directly trigger neuronal spiking in the absence of other stimulations. By bifurcation analysis, it is observed that there is saddle-node on invariant circle bifurcation, supercritical Hopf bifurcation and subcritical Hopf bifurcation appearing in the obtained two parameter bifurcation diagrams. The bifurcation structures and electric field thresholds for triggering neuron firing are determined by neuronal geometric and coupling parameters. The model predicts that the neurons with a nonsymmetric morphology between soma and dendrite, are more sensitive to electric field stimulus than those with the spherical structure. These findings suggest that neuronal geometric features play a crucial role in electric field effects on the polarization of neuronal compartments. Moreover, by determining the electric field threshold of our biophysical model, we could accurately distinguish between suprathreshold and subthreshold electric fields. Our study highlights the effects of extracellular electric field on neuronal activity from the biophysical modeling point of view. These insights into the dynamical mechanism of electric field may contribute to the investigation and development of electromagnetic therapies, and the model in our study could be further extended to a neuronal network in which the effects of electric fields on

  15. Mucosal versus muscle pain sensitivity in provoked vestibulodynia

    Directory of Open Access Journals (Sweden)

    Witzeman K

    2015-08-01

    Full Text Available Kathryn Witzeman,1 Ruby HN Nguyen,2 Alisa Eanes,3 Sawsan As-Sanie,4 Denniz Zolnoun51Department of Obstetrics and Gynecology, Denver Health Medical Center, Denver, CO, 2Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, 3Pelvic Pain Research Unit, Division of Advanced Laparoscopy and Pelvic Pain, Department of Obstetrics and Gynecology, University of North Carolina School of Medicine, Chapel Hill, NC, 4Department of Obstetrics and Gynecology, Division of Minimally Invasive Gynecologic Surgery, University of Michigan, Ann Arbor, MI, 5Department of Obstetrics and Gynecology and Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, NC, USABackground: An estimated 8.3%–16% of women experience vulvovaginal discomfort during their lifetime. Frequently these patients report provoked pain on contact or with attempted intercourse, commonly referred to as provoked vestibulodynia (PVD. Despite the burden of this condition, little is known about its potential etiologies including pelvic floor muscular dysfunction and mucosal components. This knowledge would be beneficial in developing targeted therapies including physical therapy.Objective: To explore the relative contribution of mucosal versus muscle pain sensitivity on pain report from intercourse among women with PVD.Design: In this proof of concept study, 54 women with PVD underwent a structured examination assessing mucosal and pelvic muscle sensitivity.Methods: We examined three mucosal sites in the upper and lower vestibule. Patients were asked to rate their pain on cotton swab palpation of the mucosa using a 10-point visual analog scale. Muscle pain was assessed using transvaginal application of pressure on right and left puborectalis, and the perineal muscle complex. The Gracely pain scale (0–100 was used to assess the severity of pain with intercourse, with women rating the lowest, average, and highest pain levels; a 100 rating the

  16. Sizing Dynamic Wireless Charging for Light-Duty Electric Vehicles in Roadway Applications

    Energy Technology Data Exchange (ETDEWEB)

    Foote, Andrew P [ORNL; Ozpineci, Burak [ORNL; Chinthavali, Madhu Sudhan [ORNL; Li, Jan-Mou [ORNL

    2016-01-01

    Dynamic wireless charging is a possible cure for the range limitations seen in electric vehicles (EVs) once implemented in highways or city streets. The contribution of this paper is the use of experimental data to show that the expected energy gain from a dynamic wireless power transfer (WPT) system is largely a function of average speed, which allows the power level and number of coils per mile of a dynamic WPT system to be sized for the sustained operation of an EV. First, data from dynamometer testing is used to determine the instantaneous energy requirements of a light-duty EV. Then, experimental data is applied to determine the theoretical energy gained by passing over a coil as a function of velocity and power level. Related simulations are performed to explore possible methods of placing WPT coils within roadways with comparisons to the constant velocity case. Analyses with these cases demonstrate what system ratings are needed to meet the energy requirements of the EV. The simulations are also used to determine onboard energy storage requirements for each driving cycle.

  17. Machine Learning for Identifying Demand Patterns of Home Energy Management Systems with Dynamic Electricity Pricing

    Directory of Open Access Journals (Sweden)

    Derck Koolen

    2017-11-01

    Full Text Available Energy management plays a crucial role in providing necessary system flexibility to deal with the ongoing integration of volatile and intermittent energy sources. Demand Response (DR programs enhance demand flexibility by communicating energy market price volatility to the end-consumer. In such environments, home energy management systems assist the use of flexible end-appliances, based upon the individual consumer’s personal preferences and beliefs. However, with the latter heterogeneously distributed, not all dynamic pricing schemes are equally adequate for the individual needs of households. We conduct one of the first large scale natural experiments, with multiple dynamic pricing schemes for end consumers, allowing us to analyze different demand behavior in relation with household attributes. We apply a spectral relaxation clustering approach to show distinct groups of households within the two most used dynamic pricing schemes: Time-Of-Use and Real-Time Pricing. The results indicate that a more effective design of smart home energy management systems can lead to a better fit between customer and electricity tariff in order to reduce costs, enhance predictability and stability of load and allow for more optimal use of demand flexibility by such systems.

  18. Characterization of applied tensile stress using domain wall dynamic behavior of grain-oriented electrical steel

    Science.gov (United States)

    Qiu, Fasheng; Ren, Wenwei; Tian, Gui Yun; Gao, Bin

    2017-06-01

    Stress measurement that provides early indication of stress status has become increasingly demanding in the field of Non-destructive testing and evaluation (NDT&E). Bridging the correlation between micro magnetic properties and the applied tensile stress is the first conceptual step to come up with a new method of non-destructive testing. This study investigates the characterization of applied tensile stress with in-situ magnetic domain imaging and their dynamic behaviors by using magneto-optical Kerr effect (MOKE) microscopy assisted with magneto-optical indicator film (MOIF). Threshold magnetic field (TMF) feature to reflect 180 ° domain wall (DW) characteristics behaviors in different grains is proposed for stress detection. It is verified that TMF is a threshold feature with better sensitivity and brings linear correlation for stress characterization in comparison to classical coercive field, remanent magnetization, hysteresis loss and permeability parameters. The results indicate that 180 ° DWs dynamic in the inner grain is highly correlated with stress. The DW dynamics of turn over (TO) tests for different grains is studied to illustrate the repeatability of TMF. Experimental tests of high permeability grain oriented (HGO) electrical steels under stress loading have been conducted to verify this study.

  19. Nonlinear dynamic behaviors of permanent magnet synchronous motors in electric vehicles caused by unbalanced magnetic pull

    Science.gov (United States)

    Xiang, Changle; Liu, Feng; Liu, Hui; Han, Lijin; Zhang, Xun

    2016-06-01

    Unbalanced magnetic pull (UMP) plays a key role in nonlinear dynamic behaviors of permanent magnet synchronous motors (PMSM) in electric vehicles. Based on Jeffcott rotor model, the stiffness characteristics of the rotor system of the PMSM are analyzed and the nonlinear dynamic behaviors influenced by UMP are investigated. In free vibration study, eigenvalue-based stability analysis for multiple equilibrium points is performed which offers an insight in system stiffness. Amplitude modulation effects are discovered of which the mechanism is explained and the period of modulating signal is carried out by phase analysis and averaging method. The analysis indicates that the effects are caused by the interaction of the initial phases of forward and backward whirling motions. In forced vibration study, considering dynamic eccentricity, frequency characteristics revealing softening type are obtained by harmonic balance method, and the stability of periodic solution is investigated by Routh-Hurwitz criterion. The frequency characteristics analysis indicates that the response amplitude is limited in the range between the amplitudes of the two kinds of equilibrium points. In the vicinity of the continuum of equilibrium points, the system hardly provides resistance to bending, and hence external disturbances easily cause loss of stability. It is useful for the design of the PMSM with high stability and low vibration and acoustic noise.

  20. Dynamic thermal characteristics of heat pipe via segmented thermal resistance model for electric vehicle battery cooling

    Science.gov (United States)

    Liu, Feifei; Lan, Fengchong; Chen, Jiqing

    2016-07-01

    Heat pipe cooling for battery thermal management systems (BTMSs) in electric vehicles (EVs) is growing due to its advantages of high cooling efficiency, compact structure and flexible geometry. Considering the transient conduction, phase change and uncertain thermal conditions in a heat pipe, it is challenging to obtain the dynamic thermal characteristics accurately in such complex heat and mass transfer process. In this paper, a ;segmented; thermal resistance model of a heat pipe is proposed based on thermal circuit method. The equivalent conductivities of different segments, viz. the evaporator and condenser of pipe, are used to determine their own thermal parameters and conditions integrated into the thermal model of battery for a complete three-dimensional (3D) computational fluid dynamics (CFD) simulation. The proposed ;segmented; model shows more precise than the ;non-segmented; model by the comparison of simulated and experimental temperature distribution and variation of an ultra-thin micro heat pipe (UMHP) battery pack, and has less calculation error to obtain dynamic thermal behavior for exact thermal design, management and control of heat pipe BTMSs. Using the ;segmented; model, the cooling effect of the UMHP pack with different natural/forced convection and arrangements is predicted, and the results correspond well to the tests.

  1. High-energy drinks may provoke aortic dissection.

    Science.gov (United States)

    Jonjev, Zivojin S; Bala, Gustav

    2013-05-01

    High-energy drinks have become extremely popular after Red Bull's promotion at 1987 in Austria and 1997 in the United States. Since then, we witnessed spectacular increase in different brands, caffeine content and market consumption all over the world. However, there are no reports published in the scientific literature related with detrimental side effects after heavy consumption of high-energy drinks. We report a series of three high-risk cardiovascular patients who had aortic dissection (De Bakey type I and II) following significant consumption of high-energy drinks. All of them required emergency surgical procedure and were remaining stable after surgery. We propose that uncontrolled consumption of high-energy drinks, especially in patients with underlying heart disease, could provoke potentially lethal cardiovascular events as well as acute aortic dissection.

  2. [Adulthood atopic dermatitis: epidemiology, clinical symptoms, provoking and prognostic factors].

    Science.gov (United States)

    Pónyai, Györgyi; Temesvári, Erzsébet; Kárpáti, Sarolta

    2007-01-07

    The prevalence of atopic diseases, including allergic rhinitis, asthma bronchiale and atopic dermatitis is increasing both in children and adults at different parts of the world. Atopic dermatitis is a chronic inflammatory skin disease affecting mostly children, but the atopic trait continues, not only for later respiratory allergies, but also for skin symptoms in adulthood. In this form dry skin, flexural lichenification, head and neck dermatitis, hand dermatitis are typical. The exact etiology of atopic dermatitis is unknown, in the background interactions of genetical predisposition, skin barrier defects and immunological and environmental factors can be verified. In the complex approach of atopic dermatitis, a pivotal role is ascribed to the evaluation and possibly the elimination of provoking factors, like gender, family structure, clothing, aero-, alimentary and contact allergens, psychosocial stress, migration, infections, and personal home environment. Authors review clinical manifestations, triggering and prognostic factors of the adulthood atopic dermatitis.

  3. Electric tuning of magnetization dynamics and electric field-induced negative magnetic permeability in nanoscale composite multiferroics.

    Science.gov (United States)

    Jia, Chenglong; Wang, Fenglong; Jiang, Changjun; Berakdar, Jamal; Xue, Desheng

    2015-06-09

    Steering magnetism by electric fields upon interfacing ferromagnetic (FM) and ferroelectric (FE) materials to achieve an emergent multiferroic response bears a great potential for nano-scale devices with novel functionalities. FM/FE heterostructures allow, for instance, the electrical manipulation of magnetic anisotropy via interfacial magnetoelectric (ME) couplings. A charge-mediated ME effect is believed to be generally weak and active in only a few angstroms. Here we present an experimental evidence uncovering a new magnon-driven, strong ME effect acting on the nanometer range. For Co92Zr8 (20 nm) film deposited on ferroelectric PMN-PT we show via ferromagnetic resonance (FMR) that this type of linear ME allows for electrical control of simultaneously the magnetization precession and its damping, both of which are key elements for magnetic switching and spintronics. The experiments unravel further an electric-field-induced negative magnetic permeability effect.

  4. System dynamics of the competition of municipal solid waste to landfill, electricity, and liquid fuel in California

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, Jessica; Malczynski, Leonard A.; Manley, Dawn Kataoka

    2014-03-01

    A quantitative system dynamics model was created to evaluate the economic and environmental tradeoffs between biomass to electricity and to liquid fuel using MSW biomass in the state of California as a case study. From an environmental perspective, landfilling represents the worst use of MSW over time, generating more greenhouse gas (GHG) emissions compared to converting MSW to liquid fuel or to electricity. MSW to ethanol results in the greatest displacement of GHG emissions per dollar spent compared to MSW to electricity. MSW to ethanol could save the state of California approximately $60 billion in energy costs by 2050 compared to landfilling, while also reducing GHG emissions state-wide by approximately 140 million metric tons during that timeframe. MSW conversion to electricity creates a significant cost within the state's electricity sector, although some conversion technologies are cost competitive with existing renewable generation.

  5. A long-term/short-term model for daily electricity prices with dynamic volatility

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Stephan

    2010-09-15

    In this paper we introduce a new stochastic long-term/short-term model for short-term electricity prices, and apply it to four major European indices, namely to the German, Dutch, UK and Nordic one. We give evidence that all time series contain certain periodic (mostly annual) patterns, and show how to use the wavelet transform, a tool of multiresolution analysis, for filtering purpose. The wavelet transform is also applied to separate the long-term trend from the short-term oscillation in the seasonal-adjusted log-prices. In all time series we find evidence for dynamic volatility, which we incorporate by using a bivariate GARCH model with constant correlation. Eventually we fit various models from the existing literature to the data, and come to the conclusion that our approach performs best. For the error distribution, the Normal Inverse Gaussian distribution shows the best fit. (author)

  6. Electric analogue for the dynamics of decompression sickness bubbles: Numerical results

    Science.gov (United States)

    Zueco, Joaquín; Hernández-González, A.

    2010-01-01

    Since the development of the first decompression tables in 1908 by Boycott, Damant and Haldane, considerable research and effort have been expended in the development of safer and more rapid decompression procedures and tables. The models for gas exchange have been principally empirical and provide "safe" decompression only over a limited range of depth and bottom times. In this work a numerical method based on an electrical analogy is used to solve the system of equations simulating the growth and decay dynamics of decompression bubbles. The numerical procedure employed, which satisfies the conservation law for the flux variable and the uniqueness law for voltages, also permits the direct visualisation of the evolution of the local and/or integrated transport variables at any point or section of the medium.

  7. Electric conductivity in electrolyte solution under external electromagnetic field by nonequilibrium molecular dynamics simulation.

    Science.gov (United States)

    Yang, LiJun; Huang, KaMa

    2010-07-01

    Nonequilibrium molecular dynamics (NMD) simulations are performed to investigate the effects of an external electromagnetic (E/M) field on NaCl electrolyte solutions at different temperatures using the SPC/E model. The electromagnetic wave propagates in the z-axis direction with a frequency of 2.45 GHz, and the intensity of the E/M field is 3 x 10(4) V/m. The results indicate that as the concentration of the electrolyte solution increased, the diffusion coefficient and the ionic mobility gradually decreased, but the electric conductivity gradually increased. In addition, all three of them will be increased when the temperature is increased. But their value will be reduced when the electromagnetic field is applied.

  8. Azure Dynamics transit connect : EV2010VE : upfitting to a battery electric vehicle

    Energy Technology Data Exchange (ETDEWEB)

    Oldham, B. [Azure Dynamics Corp., Toronto, ON (Canada)

    2010-07-01

    Transit Connect is a delivery vehicle brought to North America in 2010 that was initially released in Europe as part of Ford's global platform program. The stock layout includes the front engine; front wheel drive; fuel tank in rear; gasoline in North America; and diesel in Europe. This presentation described what Azure Dynamics Corporation did to improve the engine, transmission, energy storage, power steering, air conditioning, and generator. An overview of Transit Connect was provided. The presentation discussed design consideration, with particular reference to crash worthiness; durability; and total cost of implementation. Electrical harness and the total cost of implementation were also addressed. Other topics that were presented included the glider based design; a glider based design commonized platform; and additional design features. tabs., figs.

  9. Systematic Review of the Effectiveness of Physical Therapy Modalities in Women With Provoked Vestibulodynia.

    Science.gov (United States)

    Morin, Mélanie; Carroll, Marie-Soleil; Bergeron, Sophie

    2017-07-01

    Pelvic floor muscle physical therapy is recommended in clinical guidelines for women with provoked vestibulodynia (PVD). Including isolated or combined treatment modalities, physical therapy is viewed as an effective first-line intervention, yet no systematic review concerning the effectiveness of physical therapy has been conducted. To systematically appraise the current literature on the effectiveness of physical therapy modalities for decreasing pain during intercourse and improving sexual function in women with PVD. A systematic literature search using PubMed, Scopus, CINHAL, and PEDro was conducted until October 2016. Moreover, a manual search from reference lists of included articles was performed. Ongoing trials also were reviewed using clinicaltrial.gov and ISRCTNregistry. Randomized controlled trials, prospective and retrospective cohorts, and case reports evaluating the effect of isolated or combined physical therapy modalities in women with PVD were included in the review. Main outcome measures were pain during intercourse, sexual function, and patient's perceived improvement. The literature search resulted in 43 eligible studies including 7 randomized controlled trials, 20 prospective studies, 5 retrospective studies, 6 case reports, and 6 study protocols. Most studies had a high risk of bias mainly associated with the lack of a comparison group. Another common bias was related to insufficient sample size, non-validated outcomes, non-standardized intervention, and use of other ongoing treatment. The vast majority of studies showed that physical therapy modalities such as biofeedback, dilators, electrical stimulation, education, multimodal physical therapy, and multidisciplinary approaches were effective for decreasing pain during intercourse and improving sexual function. The positive findings for the effectiveness of physical therapy modalities in women with PVD should be investigated further in robust and well-designed randomized controlled trials

  10. Electric field dynamics in nitride structures containing quaternary alloy (Al, In, Ga)N

    Energy Technology Data Exchange (ETDEWEB)

    Borysiuk, J., E-mail: jolanta.borysiuk@ifpan.edu.pl [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland); Sakowski, K.; Muziol, G.; Krukowski, S. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw (Poland); Dróżdż, P. [Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland); Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw (Poland); Korona, K. P. [Faculty of Physics, University of Warsaw, Pasteura 5, 02-093 Warsaw (Poland); Sobczak, K. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Skierbiszewski, C. [Institute of High Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw (Poland); TopGaN Ltd., Sokolowska 29/37, 01-142 Warsaw (Poland); Kaminska, A. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Department of Mathematics and Natural Sciences, College of Science, Cardinal Stefan Wyszynski University, Dewajtis 5, 01-815 Warsaw (Poland)

    2016-07-07

    Molecular beam epitaxy growth and basic physical properties of quaternary AlInGaN layers, sufficiently thick for construction of electron blocking layers (EBL), embedded in ternary InGaN layers are presented. Transmission electron microscopy (TEM) measurement revealed good crystallographic structure and compositional uniformity of the quaternary layers contained in other nitride layers, which are typical for construction of nitride based devices. The AlInGaN layer was epitaxially compatible to InGaN matrix, strained, and no strain related dislocation creation was observed. The strain penetrated for limited depth, below 3 nm, even for relatively high content of indium (7%). For lower indium content (0.6%), the strain was below the detection limit by TEM strain analysis. The structures containing quaternary AlInGaN layers were studied by time dependent photoluminescence (PL) at different temperatures and excitation powers. It was shown that PL spectra contain three peaks: high energy donor bound exciton peak from the bulk GaN (DX GaN) and the two peaks (A and B) from InGaN layers. No emission from quaternary AlInGaN layers was observed. An accumulation of electrons on the EBL interface in high-In sample and formation of 2D electron gas (2DEG) was detected. The dynamics of 2DEG was studied by time resolved luminescence revealing strong dependence of emission energy on the 2DEG concentration. Theoretical calculations as well as power-dependence and temperature-dependence analysis showed the importance of electric field inside the structure. At the interface, the field was screened by carriers and could be changed by illumination. From these measurements, the dynamics of electric field was described as the discharge of carriers accumulated on the EBL.

  11. Variability in Automated Responses of Commercial Buildings and Industrial Facilities to Dynamic Electricity Prices

    Energy Technology Data Exchange (ETDEWEB)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-16

    Changes in the electricity consumption of commercial buildings and industrial facilities (C&I facilities) during Demand Response (DR) events are usually estimated using counterfactual baseline models. Model error makes it difficult to precisely quantify these changes in consumption and understand if C&I facilities exhibit event-to-event variability in their response to DR signals. This paper seeks to understand baseline model error and DR variability in C&I facilities facing dynamic electricity prices. Using a regression-based baseline model, we present a method to compute the error associated with estimates of several DR parameters. We also develop a metric to determine how much observed DR variability results from baseline model error rather than real variability in response. We analyze 38 C&I facilities participating in an automated DR program and find that DR parameter errors are large. Though some facilities exhibit real DR variability, most observed variability results from baseline model error. Therefore, facilities with variable DR parameters may actually respond consistently from event to event. Consequently, in DR programs in which repeatability is valued, individual buildings may be performing better than previously thought. In some cases, however, aggregations of C&I facilities exhibit real DR variability, which could create challenges for power system operation.

  12. Spin-valley dynamics of electrically driven ambipolar carbon-nanotube quantum dots

    Science.gov (United States)

    Osika, E. N.; Chacón, A.; Lewenstein, M.; Szafran, B.

    2017-07-01

    An ambipolar n-p double quantum dot defined by potential variation along a semiconducting carbon-nanotube is considered. We focus on the (1e,1h) charge configuration with a single excess electron of the conduction band confined in the n-type dot and a single missing electron in the valence band state of the p-type dot for which lifting of the Pauli blockade of the current was observed in the electric-dipole spin resonance (Laird et al 2013 Nat. Nanotechnol. 8 565). The dynamics of the system driven by periodic electric field is studied with the Floquet theory and the time-dependent configuration interaction method with the single-electron spin-valley-orbitals determined for atomistic tight-binding Hamiltonian. We find that the transitions lifting the Pauli blockade are strongly influenced by coupling to a vacuum state with an empty n dot and a fully filled p dot. The coupling shifts the transition energies and strongly modifies the effective g factors for axial magnetic field. The coupling is modulated by the bias between the dots but it appears effective for surprisingly large energy splitting between the (1e,1h) ground state and the vacuum (0e, 0h) state. Multiphoton transitions and high harmonic generation effects are also discussed.

  13. Ice Storage Air-Conditioning System Simulation with Dynamic Electricity Pricing: A Demand Response Study

    Directory of Open Access Journals (Sweden)

    Chi-Chun Lo

    2016-02-01

    Full Text Available This paper presents an optimal dispatch model of an ice storage air-conditioning system for participants to quickly and accurately perform energy saving and demand response, and to avoid the over contact with electricity price peak. The schedule planning for an ice storage air-conditioning system of demand response is mainly to transfer energy consumption from the peak load to the partial-peak or off-peak load. Least Squares Regression (LSR is used to obtain the polynomial function for the cooling capacity and the cost of power consumption with a real ice storage air-conditioning system. Based on the dynamic electricity pricing, the requirements of cooling loads, and all technical constraints, the dispatch model of the ice-storage air-conditioning system is formulated to minimize the operation cost. The Improved Ripple Bee Swarm Optimization (IRBSO algorithm is proposed to solve the dispatch model of the ice storage air-conditioning system in a daily schedule on summer. Simulation results indicate that reasonable solutions provide a practical and flexible framework allowing the demand response of ice storage air-conditioning systems to demonstrate the optimization of its energy savings and operational efficiency and offering greater energy efficiency.

  14. Dynamic Modeling and Simulation of Deep Geothermal Electric Submersible Pumping Systems

    Directory of Open Access Journals (Sweden)

    Julian Kullick

    2017-10-01

    Full Text Available Deep geothermal energy systems employ electric submersible pumps (ESPs in order to lift geothermal fluid from the production well to the surface. However, rough downhole conditions and high flow rates impose heavy strain on the components, leading to frequent failures of the pump system. As downhole sensor data is limited and often unrealible, a detailed and dynamical model system will serve as basis for deeper understanding and analysis of the overall system behavior. Furthermore, it allows to design model-based condition monitoring and fault detection systems, and to improve controls leading to a more robust and efficient operation. In this paper, a detailed state-space model of the complete ESP system is derived, covering the electrical, mechanical and hydraulic subsystems. Based on the derived model, the start-up phase of an exemplary yet realistic ESP system in the Megawatt range—located at a setting depth of 950 m and producing geothermal fluid of 140 ∘ C temperature at a rate of 0.145 m 3 s − 1 —is simulated in MATLAB/Simulink. The simulation results show that the system reaches a stable operating point with realistic values. Furthermore, the effect of self-excitation between the filter capacitor and the motor inductor can clearly be observed. A full set of parameters is provided, allowing for direct model implementation and reproduction of the presented results.

  15. Prolonged Intracellular Na+ Dynamics Govern Electrical Activity in Accessory Olfactory Bulb Mitral Cells.

    Directory of Open Access Journals (Sweden)

    Asaph Zylbertal

    2015-12-01

    Full Text Available Persistent activity has been reported in many brain areas and is hypothesized to mediate working memory and emotional brain states and to rely upon network or biophysical feedback. Here, we demonstrate a novel mechanism by which persistent neuronal activity can be generated without feedback, relying instead on the slow removal of Na+ from neurons following bursts of activity. We show that mitral cells in the accessory olfactory bulb (AOB, which plays a major role in mammalian social behavior, may respond to a brief sensory stimulation with persistent firing. By combining electrical recordings, Ca2+ and Na+ imaging, and realistic computational modeling, we explored the mechanisms underlying the persistent activity in AOB mitral cells. We found that the exceptionally slow inward current that underlies this activity is governed by prolonged dynamics of intracellular Na+ ([Na+]i, which affects neuronal electrical activity via several pathways. Specifically, elevated dendritic [Na+]i reverses the Na+-Ca2+ exchanger activity, thus modifying the [Ca2+]i set-point. This process, which relies on ubiquitous membrane mechanisms, is likely to play a role in other neuronal types in various brain regions.

  16. Human Aquaporin 4 Gating Dynamics under Perpendicularly-Oriented Electric-Field Impulses: A Molecular Dynamics Study

    Directory of Open Access Journals (Sweden)

    Paolo Marracino

    2016-07-01

    Full Text Available Human aquaporin 4 has been studied using molecular dynamics (MD simulations in the absence and presence of pulses of external static electric fields. The pulses were 10 ns in duration and 0.012–0.065 V/Å in intensity acting along both directions perpendicular to the pores. Water permeability and the dipolar response of all residues of interest (including the selectivity filter within the pores have been studied. Results showed decreased levels of water osmotic permeability within aquaporin channels during orthogonally-oriented field impulses, although care must be taken with regard to statistical certainty. This can be explained observing enhanced “dipolar flipping” of certain key residues, especially serine 211, histidine 201, arginine 216, histidine 95 and cysteine 178. These residues are placed at the extracellular end of the pore (serine 211, histidine 201, and arginine 216 and at the cytoplasm end (histidine 95 and cysteine 178, with the key role in gating mechanism, hence influencing water permeability.

  17. Lessons Learned from Dynamic Linking of a Hydrology Model with an Electricity Sector Model

    Science.gov (United States)

    Cohen, S. M.; Newmark, R. L.; Miara, A.; Proussevitch, A. A.; Corsi, F.; Fekete, B. M.; Macknick, J.; Vorosmarty, C. J.

    2016-12-01

    Energy systems models and climate-driven hydrological models are designed and operate at different temporal and spatial scales due to the unique physical and infrastructure constraints of the systems that they represent. As the research community seeks to explicitly represent the complex interactions of the energy sector with climate conditions and hydrological resources, these scale inconsistencies present significant technical and conceptual challenges to traditional modeling approaches. To address these challenges, a multi-institution consortium of researchers has been exploring unique approaches to linking energy systems and climate-driven hydrological models to better understand how these different coupling approaches affect model outcomes and computation time. The present framework links the Water Balance Model (WBM) and the Thermoelectric Power and Thermal Pollution Model (TP2M), which evaluate hydrological conditions under a variety of climate and power plant configuration conditions, with the Regional Energy Deployment Systems (ReEDS) model, an electricity sector capacity expansion model. ReEDS is a more spatially and temporally aggregated model than WBM/TP2M, so model coupling requires disaggregating ReEDS deployment and dispatch results for use in site-specific hydrological calculations. WBM and TP2M are used to evaluate the feasibility of ReEDS output under highly resolved geophysical constraints and river network dynamics, and infeasible electricity dispatch can be fed back to constraints on the electric sector capacity expansion in ReEDS. An initial case study of modeling coupling was conducted in the Northeastern United States, and the work is being expanded to the contiguous United States to evaluate twenty climate scenarios under three different policy scenarios. This unique coupling approach across modeling platforms from different institutions is exploring mechanisms to automate model feedbacks at different time steps to demonstrate feasibility

  18. Predictive-model-based dynamic coordination control strategy for power-split hybrid electric bus

    Science.gov (United States)

    Zeng, Xiaohua; Yang, Nannan; Wang, Junnian; Song, Dafeng; Zhang, Nong; Shang, Mingli; Liu, Jianxin

    2015-08-01

    Parameter-matching methods and optimal control strategies of the top-selling hybrid electric vehicle (HEV), namely, power-split HEV, are widely studied. In particular, extant research on control strategy focuses on the steady-state energy management strategy to obtain better fuel economy. However, given that multi-power sources are highly coupled in power-split HEVs and influence one another during mode shifting, conducting research on dynamic coordination control strategy (DCCS) to achieve riding comfort is also important. This paper proposes a predictive-model-based DCCS. First, the dynamic model of the objective power-split HEV is built and the mode shifting process is analyzed based on the developed model to determine the reason for the system shock generated. Engine torque estimation algorithm is then designed according to the principle of the nonlinear observer, and the prediction model of the degree of shock is established based on the theory of model predictive control. Finally, the DCCS with adaptation for a complex driving cycle is realized by combining the feedback control and the predictive model. The presented DCCS is validated on the co-simulation platform of AMESim and Simulink. Results show that the shock during mode shifting is well controlled, thereby improving riding comfort.

  19. Cooling of electrically insulated high voltage electrodes down to 30 mK: Dynamic measurements

    CERN Document Server

    Eisel, T; Burghart, G; Feigl, S; Haug, F; Koettig, T

    2011-01-01

    AEgIS [1] is an antimatter experiment, using high voltage electrodes at 100 mK. Two possible principles to cool these electrodes with a dilution refrigerator are investigated: the Rod and the Sandwich. Both designs are described in detail in [2]. The Sandwich design is discussed in the present work. It consists of an electrically insulating sapphire plate covered with indium on both sides. Dynamic measurements are performed in order to estimate the influence of time depending heat loads on different Sandwich designs. From these data the Sandwich’s thermal diffusivity is derived and compared to previous measurements using a static heat load. The lowest resistivity of the Sandwich is achieved with an indium vapor deposition onto polished sapphire (26 cm2K4/W at 30 mK). The same sandwich shows the best, i.e. highest thermal diffusivity (0.23 mm2/s at 70 mK). However, the results of the static and the dynamic measurements show some interesting and contrary tendencies.

  20. DYNAMICS OF ELECTRIC CURRENTS, MAGNETIC FIELD TOPOLOGY, AND HELIOSEISMIC RESPONSE OF A SOLAR FLARE

    Energy Technology Data Exchange (ETDEWEB)

    Sharykin, I. N.; Kosovichev, A. G. [Big Bear Solar Observatory, New Jersey Institute of Technology, Big Bear City, CA 92314 (United States)

    2015-07-20

    The solar flare on 2011 July 30 was of a modest X-ray class (M9.3), but it made a strong photospheric impact and produced a “sunquake,” which was observed with the Helioseismic and Magnetic Imager on board NASA's Solar Dynamics Observatory. In addition to the helioseismic waves, the flare caused a large expanding area of white-light emission and was accompanied by the rapid formation of a sunspot structure in the flare region. The flare produced hard X-ray (HXR) emission less then 300 keV and no coronal mass ejection (CME). The absence of CME rules out magnetic rope eruption as a mechanism of helioseismic waves. The sunquake impact does not coincide with the strongest HXR source, which contradicts the standard beam-driven mechanism of sunquake generation. We discuss the connectivity of the flare energy release with the electric currents dynamics and show the potential importance of high-speed plasma flows in the lower solar atmosphere during the flare energy release.

  1. Jump and pull-in dynamics of an electrically actuated bistable MEMS device

    KAUST Repository

    Ruzziconi, Laura

    2014-09-01

    This study analyzes a theoretical bistable MEMS device, which exhibits a considerable versatility of behavior. After exploring the coexistence of attractors, we focus on each rest position, and investigate the final outcome, when the electrodynamic voltage is suddenly applied. Our aim is to describe the parameter range where each attractor may practically be observed under realistic conditions, when an electric load is suddenly applied. Since disturbances are inevitably encountered in experiments and practice, a dynamical integrity analysis is performed in order to take them into account. We build the integrity charts, which examine the practical vulnerability of each attractor. A small integrity enhances the sensitivity of the system to disturbances, leading in practice either to jump or to dynamic pull-in. Accordingly, the parameter range where the device, subjected to a suddenly applied load, can operate in safe conditions with a certain attractor is smaller, and sometimes considerably smaller, than in the theoretical predictions. While we refer to a particular case-study, the approach is very general.

  2. Nonlinear dynamics of an electrically actuated mems device: Experimental and theoretical investigation

    KAUST Repository

    Ruzziconi, Laura

    2013-11-15

    This study deals with an experimental and theoretical investigation of an electrically actuated micro-electromechanical system (MEMS). The experimental nonlinear dynamics are explored via frequency sweeps in a neighborhood of the first symmetric natural frequency, at increasing values of electrodynamic excitation. Both the non-resonant branch, the resonant one, the jump between them, and the presence of a range of inevitable escape (dynamic pull-in) are observed. To simulate the experimental behavior, a single degree-offreedom spring mass model is derived, which is based on the information coming from the experimentation. Despite the apparent simplicity, the model is able to catch all the most relevant aspects of the device response. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Nevertheless, the theoretical predictions are not completely fulfilled in some aspects. In particular, the range of existence of each attractor is smaller in practice than in the simulations. This is because, under realistic conditions, disturbances are inevitably encountered (e.g. discontinuous steps when performing the sweeping, approximations in the modeling, etc.) and give uncertainties to the operating initial conditions. A reliable prediction of the actual (and not only theoretical) response is essential in applications. To take disturbances into account, we develop a dynamical integrity analysis. Integrity profiles and integrity charts are performed. They are able to detect the parameter range where each branch can be reliably observed in practice and where, instead, becomes vulnerable. Moreover, depending on the magnitude of the expected disturbances, the integrity charts can serve as a design guideline, in order to effectively operate the device in safe condition, according to the desired outcome. Copyright © 2013 by ASME.

  3. Pain Symptoms in Fibromyalgia Patients with and without Provoked Vulvodynia

    Directory of Open Access Journals (Sweden)

    Anna Ghizzani

    2014-01-01

    Full Text Available Objective. The aim of the study was to compare the pain symptoms of fibromyalgia patients exhibiting (FMS+PVD and not exhibiting (FMS comorbidity with provoked vulvodynia. Study Design. The case control study was performed in 39 patients who had been diagnosed with FMS and accepted to undergo gynaecological examination and in 36 healthy women (C. All patients completed standardized questionnaires for pain intensity, pain area, and psychological functioning. The gynaecological examination included vulvar pain pressure reactivity (Q-tip, pelvic tone assessment (Kegel manoeuver, and a semistructured interview collecting detailed information about pelvic symptoms and sexual function. Results. FMS+PVD patients displayed a higher number of associated symptoms than FMS patients. The vulvar excitability was significantly higher in FMS+PVD than in FMS and in both groups than in Controls. Half of FMS+PVD patients were positive to Kegel manoeuver and displayed higher scores in widespread pain intensity, STAI-Y2, and CESD levels than Kegel negative patients. Conclusions. The study reveals that increased vulvar pain excitability may occur in FMS patients independently of the presence of coital pain. Results suggest that coital pain develops in patients with higher FMS symptoms severity due to the cooperative effects of peripheral and central sensitization mechanisms.

  4. Alteration in the gut microbiota provokes susceptibility to tuberculosis

    Directory of Open Access Journals (Sweden)

    Nargis Khan

    2016-11-01

    Full Text Available AbstractThe microbiota that resides in the gastrointestinal tract provides essential health benefits to the host. In particular, they regulate immune homeostasis. Recently, several evidences indicate that alteration in the gut microbial community can cause infectious and non-infectious diseases. Tuberculosis (TB is the most devastating disease, inflicting mortality and morbidity. It remains unexplored, whether changes in the gut microbiota can provoke or prevent TB. In the current study, we have demonstrated the antibiotics driven changes in the gut microbial composition and their impact on the survival of Mtb in the lungs, liver and spleen of infected mice, compared to those with intact microbiota. Interestingly, dysbiosis of microbes showed significant increase in the bacterial burden in lungs and dissemination of Mtb to spleen and liver. Further, elevation in the number of Tregs and decline in the pool of IFN-γ and TNF-α releasing CD4 T cells was noticed. Interestingly, fecal transplantation in the gut microbiota disrupted animals exhibited improved Th1 immunity and lesser Tregs population. Importantly, these animals displayed reduced severity to Mtb infection. This study for the first time demonstrated the novel role of gut microbes in the susceptibility to TB and its prevention by microbial implants. In future, microbial therapies may help in treating patients suffering from TB.

  5. Electric fields generated by synchronized oscillations of microtubules, centrosomes and chromosomes regulate the dynamics of mitosis and meiosis

    Directory of Open Access Journals (Sweden)

    Zhao Yue

    2012-07-01

    Full Text Available Abstract Super-macromolecular complexes play many important roles in eukaryotic cells. Classical structural biological studies focus on their complicated molecular structures, physical interactions and biochemical modifications. Recent advances concerning intracellular electric fields generated by cell organelles and super-macromolecular complexes shed new light on the mechanisms that govern the dynamics of mitosis and meiosis. In this review we synthesize this knowledge to provide an integrated theoretical model of these cellular events. We suggest that the electric fields generated by synchronized oscillation of microtubules, centrosomes, and chromatin fibers facilitate several events during mitosis and meiosis, including centrosome trafficking, chromosome congression in mitosis and synapsis between homologous chromosomes in meiosis. These intracellular electric fields are generated under energy excitation through the synchronized electric oscillations of the dipolar structures of microtubules, centrosomes and chromosomes, three of the super-macromolecular complexes within an animal cell.

  6. Molecular dynamics simulation of the electrical double layer in ionic liquids

    Science.gov (United States)

    Kislenko, S. A.; Amirov, R. H.; Samoylov, I. S.

    2013-03-01

    The structure of the electrical double layer in the strongly coupled ionic liquid l-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) near a basal plane of graphite was investigated by molecular dynamics simulation. It is found that near an uncharged surface the ionic liquid structure differs from its bulk structure and represents a well-ordered region, extending over ~2 nm from the surface. Interfacial layering is clearly observed at the surface. Ions adsorbed at the uncharged surface form the 2D molecular clusters of two types. In the first cluster type anions are self-assembled in a triangular lattice (containing ~5÷10 ions) while a cation subsystem is disordered. In the second one cations and anions self-assembled in a honeycomb lattice. The behavior of the screening potential in the ionic liquid [BMIM] [PF6] near the charged graphite surface with the charge density in the range -1.7 <= σ <= 1.7 μC/cm2 was investigated. It was shown that the potential is a nonmonotonic function of distance. Asymmetric behavior of the screening potential at surface charge densities equal in magnitude and opposite in sign was detected. It was shown that the local self-diffusion coefficients of ions in the vicinity of the surface correlate with the local ion density. Finally, the influence of temperature on the screening potential in the vicinity of a charged graphite surface has been studied. It was shown that the increase of temperature from 300 K to 400 K induces the decrease of the potential drop across the interface that implies the increase of the capacitance of the electrical double layer.

  7. Reconnection electric field estimates and dynamics of high-latitude boundaries during a substorm

    Directory of Open Access Journals (Sweden)

    T. Pitkänen

    2009-05-01

    Full Text Available The dynamics of the polar cap and the auroral oval are examined in the evening sector during a substorm period on 25 November 2000 by using measurements of the EISCAT incoherent scatter radars, the north-south chain of the MIRACLE magnetometer network, and the Polar UV Imager.

    The location of the polar cap boundary (PCB is estimated from electron temperature measurements by the mainland low-elevation EISCAT VHF radar and the 42 m antenna of the EISCAT Svalbard radar. A comparison to the poleward auroral emission (PAE boundary by the Polar UV Imager shows that in this event the PAE boundary is typically located 0.7° of magnetic latitude poleward of the PCB by EISCAT. The convection reversal boundary (CRB is determined from the 2-D plasma drift velocity extracted from the dual-beam VHF data. The CRB is located 0.5–1° equatorward of the PCB indicating the existence of viscous-driven antisunward convection on closed field lines.

    East-west equivalent electrojets are calculated from the MIRACLE magnetometer data by the 1-D upward continuation method. In the substorm growth phase, electrojets together with the polar cap boundary move gradually equatorwards. During the substorm expansion phase, the Harang discontinuity (HD region expands to the MLT sector of EISCAT. In the recovery phase the PCB follows the poleward edge of the westward electrojet.

    The local ionospheric reconnection electric field is calculated by using the measured plasma velocities in the vicinity of the polar cap boundary. During the substorm growth phase, values between 0 and 10 mV/m are found. During the late expansion and recovery phase, the reconnection electric field has temporal variations with periods of 7–27 min and values from 0 to 40 mV/m. It is shown quantitatively, for the first time to our knowledge, that intensifications in the local reconnection electric field correlate with appearance of auroral poleward boundary intensifications (PBIs

  8. Cue-Provoked Craving and Nicotine Replacement Therapy in Smoking Cessation

    Science.gov (United States)

    Waters, Andrew J.; Shiffman, Saul; Sayette, Michael A.; Paty, Jean A.; Gwaltney, Chad J.; Balabanis, Mark H.

    2004-01-01

    Cue exposure paradigms have been used to examine reactivity to smoking cues. However, it is not known whether cue-provoked craving is associated with smoking cessation outcomes or whether cue reactivity can be attenuated by nicotine replacement therapy (NRT) in clinical samples. Cue-provoked craving ratings and reaction time responses were…

  9. Exploring action potential initiation in neurons exposed to DC electric fields through dynamical analysis of conductance-based model

    Science.gov (United States)

    Yi, Guo-Sheng; Wang, Jiang; Han, Chun-Xiao; Deng, Bin; Wei, Xi-Le; Jin, Qi-Tao

    2014-05-01

    Noninvasive direct current (DC) electric stimulation of central nervous system is today a promising therapeutic option to alleviate the symptoms of a number of neurological disorders. Despite widespread use of this noninvasive brain modulation technique, a generalizable explanation of its biophysical basis has not been described which seriously restricts its application and development. This paper investigated the dynamical behaviors of Hodgkin's three classes of neurons exposed to DC electric field based on a conductance-based neuron model. With phase plane and bifurcation analysis, the different responses of each class of neuron to the same stimulation are shown to derive from distinct spike initiating dynamics. Under the effects of negative DC electric field, class 1 neuron generates repetitive spike through a saddle-node on invariant circle (SNIC) bifurcation, while it ceases this repetitive behavior through a Hopf bifurcation; Class 2 neuron generates repetitive spike through a Hopf bifurcation, meanwhile it ceases this repetitive behavior also by a Hopf bifurcation; Class 3 neuron can generate single spike through a quasi-separatrix-crossing (QSC) at first, then it generates repetitive spike through a Hopf bifurcation, while it ceases this repetitive behavior through a SNIC bifurcation. Furthermore, three classes of neurons' spiking frequency f-electric field E (f-E) curves all have parabolic shape. Our results highlight the effects of external DC electric field on neuronal activity from the biophysical modeling point of view. It can contribute to the application and development of noninvasive DC brain modulation technique.

  10. Dynamics of electricity efficiency in commercial air-distribution systems in Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Christiansson, Lena

    1996-04-01

    This paper illustrates the long-term potential for reducing future electricity demand for air-distribution in commercial buildings in Sweden. The objective has been to develop a general quantitative scenario-based framework to describe some possible paths for electricity demand for air distribution and to analyze how governmental and utility-sponsored policy measures can affect electricity demand. The focus is on improved electricity efficiency, i.e. a reduction of electricity demand for the same level of services. The results suggest that higher electricity prices will not be very effective in reducing electricity demand, whereas significant electricity savings can be reached by implementing various policy programs, particularly standards. 56 refs, 4 figs, 5 tabs

  11. Synchronization Dynamics of Two Heterogeneous Chaotic Rulkov Neurons with Electrical Synapses

    Science.gov (United States)

    Cheng, Lifang; Cao, Hongjun

    Two heterogeneous chaotic Rulkov neurons with electrical synapses are investigated in this paper. First, we study the ability of the second neuron to modify the dynamics of the first neuron. It is shown that when the parameters of the first neuron are located at the vicinity of the Neimark-Sacker bifurcation curves the first firing neuron can be controlled into the quiescent state when coupled with the second neuron. While the parameters of the first neuron are near the flip bifurcation curves the first firing neuron cannot be suppressed. Second, we discuss burst synchronization for two bursting neurons and two tonic spiking neurons. It is shown that two heterogeneous chaotic Rulkov neurons with tonic spiking firing cannot reach anti-phase synchronization under the inhibitory coupling, which is different from the property of nonchaotic Rulkov neurons. Finally, we show that for two bursting neurons if the coupling is strong enough then burst synchronization can be converted into spike synchronization. However, complete synchronization cannot be achieved for any strong coupling.

  12. Using System Dynamics to Define, Study, and Implement Smart Control Strategies on the Electric Power Grid

    Energy Technology Data Exchange (ETDEWEB)

    Lyle G. Roybal; Robert F Jeffers

    2013-07-01

    The United States electric power grid is the most complex and expansive control system in the world. Local generation control occurs at individual units based on response time and unit economics, larger regional control coordinates unit response to error conditions, and high level large-area regional control is ultimately administered by a network of humans guided by economic and resiliency related factors. Under normal operating conditions, the grid is a relatively slow moving entity that exhibits high inertia to outside stimuli, and behaves along repeatable diurnal and seasonal patterns. However, that paradigm is quickly changing because of the increasing implementation of renewable generation sources. Renewable generators by nature cannot be tightly controlled or scheduled. They appear like a negative load to the system with all of the variability associated with load on a larger scale. Also, grid-reactive loads (i.e. smart devices) can alter their consumption based on price or demand rules adding more variability to system behavior. This paper demonstrates how a systems dynamic modeling approach capable of operating over multiple time scales, can provide valuable insight into developing new “smart-grid” control strategies and devices needed to accommodate renewable generation and regulate the frequency of the grid.

  13. Modelling and Simulation of Fuel Cell Dynamics for Electrical Energy Usage of Hercules Airplanes

    Directory of Open Access Journals (Sweden)

    Hamid Radmanesh

    2014-01-01

    Full Text Available Dynamics of proton exchange membrane fuel cells (PEMFC with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC’s output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC’s output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC’s output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane.

  14. Modelling and simulation of fuel cell dynamics for electrical energy usage of Hercules airplanes.

    Science.gov (United States)

    Radmanesh, Hamid; Heidari Yazdi, Seyed Saeid; Gharehpetian, G B; Fathi, S H

    2014-01-01

    Dynamics of proton exchange membrane fuel cells (PEMFC) with hydrogen storage system for generating part of Hercules airplanes electrical energy is presented. Feasibility of using fuel cell (FC) for this airplane is evaluated by means of simulations. Temperature change and dual layer capacity effect are considered in all simulations. Using a three-level 3-phase inverter, FC's output voltage is connected to the essential bus of the airplane. Moreover, it is possible to connect FC's output voltage to airplane DC bus alternatively. PID controller is presented to control flow of hydrogen and oxygen to FC and improve transient and steady state responses of the output voltage to load disturbances. FC's output voltage is regulated via an ultracapacitor. Simulations are carried out via MATLAB/SIMULINK and results show that the load tracking and output voltage regulation are acceptable. The proposed system utilizes an electrolyser to generate hydrogen and a tank for storage. Therefore, there is no need for batteries. Moreover, the generated oxygen could be used in other applications in airplane.

  15. Analysis of Student’s Skills on the Concept Dynamic Electricity

    Science.gov (United States)

    Safrina, I.; Maknun, J.; Hasanah, L.

    2017-09-01

    Physics becomes one of the science lessons in schools that guide student to apply materials in everyday life and commnicating the results natural phenomena. This study intended to figure out understanding skill and argumentation skill on the concept dynamic electricity. This study was descriptive research of senior high school students in South Tangerang. Technique of collecting data was done by test method and interview. The understanding skill refers to indicators of conceptual understanding in the cognitive process of Bloom’s Taxonomy Revision, which contains the indicators were explaining, interpreting, summarizing, comparing, classifying, and inferring. While the argumentation skill refers to Toulmin’s Argumentation Pattern (TAP) which contains the components of claim, evidence, warrant, and backing. The result showed that ability of explaining was higher and ability of comparing was lower. The component of claim was higher and backing was lower. Based on the result, it can be conclude that understanding skill and argumentation skill still less. They have been teached to student with inovation learning method.

  16. Inductively coupled TI-MPD spacecraft electric propulsion. [thermionic magnetoplasma dynamic thruster design

    Science.gov (United States)

    Britt, E. J.; Clark, K. E.; Pawlik, E. V.

    1976-01-01

    A nuclear electric propulsion concept using a thermionic reactor inductively coupled to a magnetoplasma-dynamic (MPD) accelerator is described and the results of preliminary analyses are presented. In this system, the thermionic generating unit operates continuously at a power level of approximately 0.4 MW, while the MPD thruster operates intermittently at higher voltages and power levels. Energy storage is provided by building up a large current in an inductor. Periodically, the charging current is interrupted and the energy stored in the magnetic field of the inductor is utilized for a short duration thrust pulse. A typical thrust pulse is characterized by a power level of 1 to 4 MWe, a duration of 1 msec, and a duty cycle of approximately 20%. Results of the preliminary analysis show that approximately 85 to 90% of the power available from the thermionic converter array can be delivered to the MPD thruster for a nominal 400 kWe system with an inductive unit suitable for a flight vehicle. Optimized values of the total specific mass of the system including the thermionic reactor, the inductor, and the MPD thruster are estimated in the range of 23 to 24 kg/kWe.

  17. The influence of the dynamic ergodic divertor on the radial electric field at the Tokamak TEXTOR

    Energy Technology Data Exchange (ETDEWEB)

    Coenen, Jan Willem

    2009-11-06

    In this work the influence of external Resonant Magnetic Perturbations (RMPs) on the radial electric field Er in magnetically confined plasmas is investigated by Charge Exchange Recombination Spectroscopy (CXRS) at the Tokamak TEXTOR. Here, the RMPs are produced with the Dynamic Ergodic Divertor (DED), a set of 16 helical perturbation coils located at the high field side of TEXTOR. Within this work, the base mode number of perturbations has been m/n=6/2. We have first investigated the influence of external torque from neutral heating beams on plasma rotation and E{sub r}. The ergodic zone causes an electron loss, and subsequently a (vector)j x (vector)B force driven by the compensating ion return current. In addition, the DED changes the global confinement properties. Depending on the edge safety factor (''field line twist'') q{sub a}, either increased or decreased particle confinement is observed. In case of the increased particle confinement (IPC) the increase in density (40%) and particle confinement time {tau}{sub p} (30%) is correlated to the connection of field lines at the q=5/2 surface to the DED target, locally changing the transport properties and the E{sub r}. Transport is reduced and the E{sub r} shear is increased locally at q=5/2 up to 1.5 . 10{sup 5}s{sup -1}, while the E{sub r} becomes more positive. (orig.)

  18. Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space.

    Science.gov (United States)

    Collins, Liam; Belianinov, Alex; Somnath, Suhas; Balke, Nina; Kalinin, Sergei V; Jesse, Stephen

    2016-08-12

    Kelvin probe force microscopy (KPFM) has provided deep insights into the local electronic, ionic and electrochemical functionalities in a broad range of materials and devices. In classical KPFM, which utilizes heterodyne detection and closed loop bias feedback, the cantilever response is down-sampled to a single measurement of the contact potential difference (CPD) per pixel. This level of detail, however, is insufficient for materials and devices involving bias and time dependent electrochemical events; or at solid-liquid interfaces, where non-linear or lossy dielectrics are present. Here, we demonstrate direct recovery of the bias dependence of the electrostatic force at high temporal resolution using General acquisition Mode (G-Mode) KPFM. G-Mode KPFM utilizes high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates. We show how G-Mode KPFM can be used to capture nanoscale CPD and capacitance information with a temporal resolution much faster than the cantilever bandwidth, determined by the modulation frequency of the AC voltage. In this way, G-Mode KPFM offers a new paradigm to study dynamic electric phenomena in electroactive interfaces as well as a promising route to extend KPFM to the solid-liquid interface.

  19. A sub-μs thermal time constant electrically driven Pt nanoheater: thermo-dynamic design and frequency characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ottonello Briano, Floria, E-mail: floria@kth.se; Sohlström, Hans; Forsberg, Fredrik; Stemme, Göran; Gylfason, Kristinn B. [Micro and Nanosystems, KTH Royal Institute of Technology, Osquldas väg 10, SE-100 44 Stockholm (Sweden); Renoux, Pauline; Ingvarsson, Snorri [Science Institute, University of Iceland, Dunhaga 3, IS-107 Reykjavík (Iceland)

    2016-05-09

    Metal nanowires can emit coherent polarized thermal radiation, work as uncooled bolometers, and provide localized heating. In this paper, we engineer the temperature dynamics of electrically driven Pt nanoheaters on a silicon-on-insulator substrate. We present three designs and we electrically characterize and model their thermal impedance in the frequency range from 3 Hz to 3 MHz. Finally, we show a temperature modulation of 300 K while consuming less than 5 mW of power, up to a frequency of 1.3 MHz. This result can lead to significant advancements in thermography and absorption spectroscopy.

  20. Analysis of policy options for projects in the electricity sector in sub Saharan Africa : a system dynamics approach

    Directory of Open Access Journals (Sweden)

    Ogano, N. O.

    2017-05-01

    Full Text Available Many projects in the electricity energy sector in the Sub Saharan Africa region experience quality challenges and delays, leading to frequent power outages that slow the overall economic activity in the region and frustrate investor confidence in the region. This paper presents the systemic methods employed to evaluate the dynamic consequences of policies in the electricity energy sector projects in the region. The model uses the Vensim software to carry out the simulations. A range of illustrative scenarios are provided and analysed, and the paper compares and contrasts these different scenarios.

  1. Vehicle Dynamics Control of In-wheel Electric Motor Drive Vehicles Based on Averaging of Tire Force Usage

    Science.gov (United States)

    Masaki, Nobuo; Iwano, Haruo; Kamada, Takayoshi; Nagai, Masao

    For in-wheel electric motor drive vehicles, a new vehicle dynamics control which is based on the tire force usage rate is proposed. The new controller adopts non-linear optimal control could manage the interference between direct yaw-moment control and the tire force usage rate. The new control is considered total longitudinal and transverse tire force. Therefore the controller can prevent tire force saturation near tire force limit during cornering. Simulations and test runs by the custom made four wheel drive in-wheel motor electric vehicle show that higher driving stability performance compared to the performance of the same vehicle without control.

  2. Universal domain wall dynamics under electric field in Ta/CoFeB/MgO devices with perpendicular anisotropy.

    Science.gov (United States)

    Lin, Weiwei; Vernier, Nicolas; Agnus, Guillaume; Garcia, Karin; Ocker, Berthold; Zhao, Weisheng; Fullerton, Eric E; Ravelosona, Dafiné

    2016-11-16

    Electric field effects in ferromagnetic metal/dielectric structures provide a new route to control domain wall dynamics with low-power dissipation. However, electric field effects on domain wall velocities have only been observed so far in the creep regime where domain wall velocities are low due to strong interactions with pinning sites. Here we show gate voltage modulation of domain wall velocities ranging from the creep to the flow regime in Ta/Co 40 Fe 40 B 20 /MgO/TiO 2 structures with perpendicular magnetic anisotropy. We demonstrate a universal description of the role of applied electric fields in the various pinning-dependent regimes by taking into account an effective magnetic field being linear with the electric field. In addition, the electric field effect is found to change sign in the Walker regime. Our results are consistent with voltage-induced modification of magnetic anisotropy. Our work opens new opportunities for the study and optimization of electric field effect at ferromagnetic metal/insulator interfaces.

  3. Universal domain wall dynamics under electric field in Ta/CoFeB/MgO devices with perpendicular anisotropy

    Science.gov (United States)

    Lin, Weiwei; Vernier, Nicolas; Agnus, Guillaume; Garcia, Karin; Ocker, Berthold; Zhao, Weisheng; Fullerton, Eric E.; Ravelosona, Dafiné

    2016-01-01

    Electric field effects in ferromagnetic metal/dielectric structures provide a new route to control domain wall dynamics with low-power dissipation. However, electric field effects on domain wall velocities have only been observed so far in the creep regime where domain wall velocities are low due to strong interactions with pinning sites. Here we show gate voltage modulation of domain wall velocities ranging from the creep to the flow regime in Ta/Co40Fe40B20/MgO/TiO2 structures with perpendicular magnetic anisotropy. We demonstrate a universal description of the role of applied electric fields in the various pinning-dependent regimes by taking into account an effective magnetic field being linear with the electric field. In addition, the electric field effect is found to change sign in the Walker regime. Our results are consistent with voltage-induced modification of magnetic anisotropy. Our work opens new opportunities for the study and optimization of electric field effect at ferromagnetic metal/insulator interfaces. PMID:27848936

  4. The impact of ICT investment and energy price on industrial electricity demand: Dynamic growth model approach

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Youngsang; Lee, Jongsu; Kim, Tai-Yoo [Technology Management, Economics and Policy Program, College of Engineering, Seoul National University, Shillim-Dong San56-1, Gwanak-Ku, Seoul 151-742 (Korea)

    2007-09-15

    The authors investigate the effects of information and communications technology (ICT) investment, electricity price, and oil price on the consumption of electricity in South Korea's industries using a logistic growth model. The concept electricity intensity is used to explain electricity consumption patterns. An empirical analysis implies that ICT investment in manufacturing industries that normally consume relatively large amounts of electricity promotes input factor substitution away from the labor intensive to the electricity intensive. Moreover, results also suggest that ICT investment in some specific manufacturing sectors is conducive to the reduction of electricity consumption, whereas ICT investment in the service sector and most manufacturing sectors increases electricity consumption. It is concluded that electricity prices critically affect electricity consumption in half of South Korea's industrial sectors, but not in the other half, a finding that differs somewhat from previous research results. Reasons are suggested to explain why the South Korean case is so different. Policymakers may find this study useful, as it answers the question of whether ICT investment can ultimately reduce energy consumption and may aid in planning the capacity of South Korea's national electric power. (author)

  5. ON THE DEMAND DYNAMICS OF ELECTRICITY IN GHANA: DO EXOGENOUS NON-ECONOMIC VARIABLES COUNT?

    Directory of Open Access Journals (Sweden)

    Ishmael Ackah

    2014-04-01

    Full Text Available The purpose of this study is to identify and quantify the effect of endogenous and exogenous economic factors on electricity demand in Ghana. The Structural Time Series Model is employed due to its ability to capture exogenous non-economic variables. The findings reveal that education has significant effect on electricity consumption in both the short and the long run. Education has inverse relationship with electricity consumption implying that the more consumers are educated, the less electricity they consume. The study also reveals that price changes have less impact on electricity consumption in the short run and that efficiency in electricity consumption has improved since 1971 and will continue for the next twenty years. The study recommends that more public education should be carried out to enhance energy conservation and also, realistic prices should be charge for electricity consumption to allow private investment into the sector.

  6. Reactive molecular dynamics of the initial oxidation stages of Ni111 in pure water: effect of an applied electric field.

    Science.gov (United States)

    Assowe, O; Politano, O; Vignal, V; Arnoux, P; Diawara, B; Verners, O; van Duin, A C T

    2012-12-06

    Corrosion processes occurring in aqueous solutions are critically dependent upon the interaction between the metal electrode and the solvent. In this work, the interaction of a nickel substrate with water molecules has been investigated using reactive force field (ReaxFF) molecular dynamics simulations. This approach was originally developed by van Duin and co-workers to study hydrocarbon chemistry and the catalytic properties of organic compounds. To our knowledge, this method has not previously been used to study the corrosion of nickel. In this work, we studied the interaction of 480 molecules of water (ρ = 0.99 g·cm(-3)) with Ni(111) surfaces at 300 K. The results showed that a water "bilayer" was adsorbed on the nickel surface. In the absence of an applied electric field, no dissociation of water was observed. However, the nickel atoms at the surface were charged positively, whereas the first water layer was charged negatively, indicating the formation of an electric double layer. To study the corrosion of nickel in pure water, we introduced an external electric field between the metal and the solution. The electric field intensity varied between 10 and 20 MeV/cm. The presence of this electric field led to oxidation of the metal surface. The structural and morphological differences associated with the growth of this oxide film in the presence of the electric field were evaluated. The simulated atomic trajectories were used to analyze the atomic displacement during the reactive process. The growth of the oxide scale on the nickel surface was primarily due to the movement of anions toward the interior of the metal substrate and the migration of nickel toward the free surface. We found that increasing the electric field intensity sped up the corrosion of nickel. The results also showed that the oxide film thickness increased linearly with increasing electric field intensity.

  7. Online Energy Management of Plug-In Hybrid Electric Vehicles for Prolongation of All-Electric Range Based on Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Zeyu Chen

    2015-01-01

    Full Text Available The employed energy management strategy plays an important role in energy saving performance and exhausted emission reduction of plug-in hybrid electric vehicles (HEVs. An application of dynamic programming for optimization of power allocation is implemented in this paper with certain driving cycle and a limited driving range. Considering the DP algorithm can barely be used in real-time control because of its huge computational task and the dependence on a priori driving cycle, several online useful control rules are established based on the offline optimization results of DP. With the above efforts, an online energy management strategy is proposed finally. The presented energy management strategy concerns the prolongation of all-electric driving range as well as the energy saving performance. A simulation study is deployed to evaluate the control performance of the proposed energy management approach. All-electric range of the plug-in HEV can be prolonged by up to 2.86% for a certain driving condition. The energy saving performance is relative to the driving distance. The presented energy management strategy brings a little higher energy cost when driving distance is short, but for a long driving distance, it can reduce the energy consumption by up to 5.77% compared to the traditional CD-CS strategy.

  8. Calcium-independent disruption of microtubule dynamics by nanosecond pulsed electric fields in U87 human glioblastoma cells

    Science.gov (United States)

    Carr, Lynn; Bardet, Sylvia M.; Burke, Ryan C.; Arnaud-Cormos, Delia; Leveque, Philippe; O’Connor, Rodney P.

    2017-01-01

    High powered, nanosecond duration, pulsed electric fields (nsPEF) cause cell death by a mechanism that is not fully understood and have been proposed as a targeted cancer therapy. Numerous chemotherapeutics work by disrupting microtubules. As microtubules are affected by electrical fields, this study looks at the possibility of disrupting them electrically with nsPEF. Human glioblastoma cells (U87-MG) treated with 100, 10 ns, 44 kV/cm pulses at a frequency of 10 Hz showed a breakdown of their interphase microtubule network that was accompanied by a reduction in the number of growing microtubules. This effect is temporally linked to loss of mitochondrial membrane potential and independent of cellular swelling and calcium influx, two factors that disrupt microtubule growth dynamics. Super-resolution microscopy revealed microtubule buckling and breaking as a result of nsPEF application, suggesting that nsPEF may act directly on microtubules. PMID:28117459

  9. Effect of process parameters on the dynamic behavior of polymer electrolyte membrane fuel cells for electric vehicle applications

    Directory of Open Access Journals (Sweden)

    A.A. Abd El Monem

    2014-03-01

    Full Text Available This paper presents a dynamic mathematical model for Polymer Electrolyte Membrane “PEM” fuel cell systems to be used for electric vehicle applications. The performance of the fuel cell, depending on the developed model and taking the double layer charging effect into account, is investigated with different process parameters to evaluate their effect on the unit behavior. Thus, it will be easy to develop suitable controllers to regulate the unit operation, which encourages the use of fuel cells especially with electric vehicles applications. The steady-state performance of the fuel cell is verified using a comparison with datasheet data and curves provided by the manufacturer. The results and conclusions introduced in this paper provide a base for further investigation of fuel cells-driven dc motors for electric vehicle.

  10. Modeling of Electrical Cable Failure in a Dynamic Assessment of Fire Risk

    Science.gov (United States)

    Bucknor, Matthew D.

    Fires at a nuclear power plant are a safety concern because of their potential to defeat the redundant safety features that provide a high level of assurance of the ability to safely shutdown the plant. One of the added complexities of providing protection against fires is the need to determine the likelihood of electrical cable failure which can lead to the loss of the ability to control or spurious actuation of equipment that is required for safe shutdown. A number of plants are now transitioning from their deterministic fire protection programs to a risk-informed, performance based fire protection program according to the requirements of National Fire Protection Association (NFPA) 805. Within a risk-informed framework, credit can be taken for the analysis of fire progression within a fire zone that was not permissible within the deterministic framework of a 10 CFR 50.48 Appendix R safe shutdown analysis. To perform the analyses required for the transition, plants need to be able to demonstrate with some level of assurance that cables related to safe shutdown equipment will not be compromised during postulated fire scenarios. This research contains the development of new cable failure models that have the potential to more accurately predict electrical cable failure in common cable bundle configurations. Methods to determine the thermal properties of the new models from empirical data are presented along with comparisons between the new models and existing techniques used in the nuclear industry today. A Dynamic Event Tree (DET) methodology is also presented which allows for the proper treatment of uncertainties associated with fire brigade intervention and its effects on cable failure analysis. Finally a shielding analysis is performed to determine the effects on the temperature response of a cable bundle that is shielded from a fire source by an intervening object such as another cable tray. The results from the analyses demonstrate that models of similar

  11. Dynamic Modeling and Analysis of Power Sharing Control Strategy Based Fuel Cell/Battery Assisted Hybrid Electric Vehicle System

    OpenAIRE

    MURUGESAN, KARTHIK; SENNIAPPAN, VIJAYACHITRA

    2016-01-01

    A dynamic modeling of Fuel cell/Battery assisted hybrid electric vehicle system is presented in this article and two suitable power sharing control strategies are integrated into the system with the objective of minimizing the fuel consumption and maximizing the battery life through its safe operating limit. This prominent goal is accomplished into the developed hybrid vehicle system by incorporating suitable control strategies without compromising the drivability of the vehicle. The proposed...

  12. Water liquid-vapor interface subjected to various electric fields: A molecular dynamics study

    Science.gov (United States)

    Nikzad, Mohammadreza; Azimian, Ahmad Reza; Rezaei, Majid; Nikzad, Safoora

    2017-11-01

    Investigation of the effects of E-fields on the liquid-vapor interface is essential for the study of floating water bridge and wetting phenomena. The present study employs the molecular dynamics method to investigate the effects of parallel and perpendicular E-fields on the water liquid-vapor interface. For this purpose, density distribution, number of hydrogen bonds, molecular orientation, and surface tension are examined to gain a better understanding of the interface structure. Results indicate enhancements in parallel E-field decrease the interface width and number of hydrogen bonds, while the opposite holds true in the case of perpendicular E-fields. Moreover, perpendicular fields disturb the water structure at the interface. Given that water molecules tend to be parallel to the interface plane, it is observed that perpendicular E-fields fail to realign water molecules in the field direction while the parallel ones easily do so. It is also shown that surface tension rises with increasing strength of parallel E-fields, while it reduces in the case of perpendicular E-fields. Enhancement of surface tension in the parallel field direction demonstrates how the floating water bridge forms between the beakers. Finally, it is found that application of external E-fields to the liquid-vapor interface does not lead to uniform changes in surface tension and that the liquid-vapor interfacial tension term in Young's equation should be calculated near the triple-line of the droplet. This is attributed to the multi-directional nature of the droplet surface, indicating that no constant value can be assigned to a droplet's surface tension in the presence of large electric fields.

  13. DYNAMIC MODEL “ELECTRICITY CONSUMPTION - GDP” FOR REPUBLIC OF MOLDOVA

    Directory of Open Access Journals (Sweden)

    Sit B.M.

    2007-04-01

    Full Text Available The article is devoted to the development of econometric models of electricity consumption in Republic of Moldova with the purpose of definition of potential possibilities of GPD influence on electricity consumption processes.In this paper, we examine the causal relationship between the per capita electricity consumption and the per capita GDP for Republic of Moldova using VAR model. Our results show that there is bidirectional causality from per capita GDP to per capita electricity consumption and vice versa. The finding has significant implications from the point of view of energy conservation, emission reduction and economic development.

  14. Effects of Thought Suppression on Provoked Men’s Alcohol-Related Physical Aggression in the Laboratory

    Science.gov (United States)

    Gallagher, Kathryn E.; Lisco, Claire G.; Parrott, Dominic J.; Giancola, Peter R.

    2013-01-01

    Objective This study utilized a comprehensive theoretical approach to provide the first data on the impact of thought suppression on provoked men’s alcohol-related aggression. Method A diverse community sample (58% African-American) of males between the ages of 21 and 35 (M = 25.25) were randomly assigned to one of two beverage conditions (i.e., alcohol, no-alcohol control). Following beverage consumption, participants were provoked via reception of electric shocks and a verbal insult from a fictitious male opponent. Participants’ physical aggression was measured using a shock-based aggression task. Results Results indicated that acute alcohol intoxication significantly increased physical aggression among lower, but not higher, thought suppressing men. Conclusions Results suggest that, under conditions of interpersonal provocation, alcohol intoxication produces a myopic focus on hostile thoughts and angry affect in lower, but not higher, suppression men. This pattern of results provides support for the durability of the alcohol myopia effect and highlights the need for continued examination of alcohol’s role in the disruption of protective factors for men’s aggression. It is important for research to continue to identify modifiable cognitive variables that influence self-regulation of behavior; however, it is imperative that researchers consider the extent to which these variables withstand alcohol’s effects. PMID:25337430

  15. Electrical conductivity, dielectric response and space charge dynamics of an electroactive polymer with and without nanofiller reinforcement

    Science.gov (United States)

    Kochetov, R.; Tsekmes, I. A.; Morshuis, P. H. F.

    2015-07-01

    Electroactive polymers have gained considerable attention over the last 20 years for exhibiting a large displacement in response to electrical stimulation. The promising fields of application include wave energy converters, muscle-like actuators, sensors, robotics, and biomimetics. For an electrical engineer, electroactive polymers can be seen as a dielectric elastomer film or a compliant capacitor with a highly deformable elastomeric medium. If the elastomer is pre-stretched and pre-charged, a reduction of the tensile force lets the elastomer revert to its original form and increases the electrical potential. The light weight of electroactive polymers, low cost, high intrinsic breakdown strength, cyclical way of operation, reliable performance, and high efficiency can be exploited to utilize the elastomeric material as a transducer. The energy storage for a linear dielectric polymer is determined by its relative permittivity and the applied electric field. The latter is limited by the dielectric breakdown strength of the material. Therefore, to generate a high energy density of a flexible capacitor, the film must be used at the voltage level close to the material’s breakdown or inorganic particles with high dielectric permittivity which can be introduced into the polymer matrix. In the present study, silicone-titania elastomer nanocomposites were produced and the influence of nanoparticles on the macroscopic dielectric properties of the neat elastomer including space charge dynamics, complex permittivity, and electrical conductivity, were investigated.

  16. Evaporation of water droplets on Pt-surface in presence of external electric field—A molecular dynamics study

    Science.gov (United States)

    Hens, Abhiram; Biswas, Gautam; De, Sudipta

    2015-09-01

    Evaporation of a sessile droplet on a hot solid substrate is an important problem in fluid mechanics. It is relevant to theoretical issues in heat transfer as well as several practical applications. This study investigates the spreading and evaporation of a nanoscale water droplet on a solid platinum surface. The major objective was to analyze the effect of an external electric field on these phenomena. Varying the intensity and direction of the external electric field, a series of molecular dynamics simulations were carried out to understand these phenomena at a molecular level. The results reveal that a horizontal electric field assists in droplet spreading, whereas a vertical electric field enhances the rate of evaporation for a certain range of field intensities. It also shows that the substrate temperature plays an important role in such processes. It is seen that the effect of an external electric field on droplet evaporation becomes significant at an intermediate range of surface temperatures and this effect is not clearly visible for either very high or very low range of surface temperatures.

  17. Heightened Pelvic Floor Muscle Tone and Altered Contractility in Women With Provoked Vestibulodynia.

    Science.gov (United States)

    Morin, Mélanie; Binik, Yitzchak M; Bourbonnais, Daniel; Khalifé, Samir; Ouellet, Stéphane; Bergeron, Sophie

    2017-04-01

    Pelvic floor muscle (PFM) dysfunctions are reported to be involved in provoked vestibulodynia (PVD). Although heightened PFM tone has been suggested, the relative contribution of active and passive components of tone remains misunderstood. Likewise, alterations in PFM contractility have been scarcely studied. To compare PFM tone, including the relative contribution of its active and passive components, and muscular contractility in women with PVD and asymptomatic controls. Fifty-six asymptomatic women and 56 women with PVD participated in the study. The PVD diagnosis was confirmed by a gynecologist based on a standardized examination. PFM function was evaluated using a dynamometric speculum combined with surface electromyography (EMG). PFM general tone was evaluated in static conditions at different vaginal apertures and during repeated dynamic cyclic stretching. The active contribution of tone was characterized using the ratio between EMG in a static position and during stretching and the proportion of women presenting PFM activation during stretching. Contribution of the passive component was evaluated using resting forces, stiffness, and hysteresis in women sustaining a negligible EMG signal during stretching. PFM contractility, such as strength, speed of contraction, coordination, and endurance, also was assessed during voluntary isometric efforts. Greater PFM resting forces and stiffness were found in women with PVD compared with controls, indicating an increased general tone. An increased active component also was found in women with PVD because they presented a superior EMG ratio, and a larger proportion of them presented PFM activation during stretching. Higher passive properties also were found in women with PVD. Women with PVD also showed decreased strength, speed of contraction, coordination, and endurance compared with controls. Findings provide further evidence of the contribution of PFM alterations in the etiology of PVD. These alterations should be

  18. Recent evolution of Brazil's economy, the macroeconomic outlook and electricity sector dynamics

    OpenAIRE

    Castro, Nivalde J. de; Rosental, Rubens; Bueno, Daniel

    2009-01-01

    With reference to a very favorable macroeconomic context of the Brazilian economy in 2007, the objective of this paper is to analyze the impacts on consumption of electricity and the expansion of installed generating capacity, it seeking a position signal on the real prospects of balance of imbalance between supply and demand of electric energy for the coming years.

  19. System Dynamic Model for the Accumulation of Renewable Electricity using Power-to-Gas and Power-to-Liquid Concepts

    Directory of Open Access Journals (Sweden)

    Blumberga Andra

    2015-12-01

    Full Text Available When the renewable energy is used, the challenge is match the supply of intermittent energy with the demand for energy therefore the energy storage solutions should be used. This paper is dedicated to hydrogen accumulation from wind sources. The case study investigates the conceptual system that uses intermitted renewable energy resources to produce hydrogen (power-to-gas concept and fuel (power-to-liquid concept. For this specific case study hydrogen is produced from surplus electricity generated by wind power plant trough electrolysis process and fuel is obtained by upgrading biogas to biomethane using hydrogen. System dynamic model is created for this conceptual system. The developed system dynamics model has been used to simulate 2 different scenarios. The results show that in both scenarios the point at which the all electricity needs of Latvia are covered is obtained. Moreover, the methodology of system dynamics used in this paper is white-box model that allows to apply the developed model to other case studies and/or to modify model based on the newest data. The developed model can be used for both scientific research and policy makers to better understand the dynamic relation within the system and the response of system to changes in both internal and external factors.

  20. Reliable fuzzy H∞ control for active suspension of in-wheel motor driven electric vehicles with dynamic damping

    Science.gov (United States)

    Shao, Xinxin; Naghdy, Fazel; Du, Haiping

    2017-03-01

    A fault-tolerant fuzzy H∞ control design approach for active suspension of in-wheel motor driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The controller is designed based on the quarter-car active suspension model with a dynamic-damping-in-wheel-motor-driven-system, in which the suspended motor is operated as a dynamic absorber. The Takagi-Sugeno (T-S) fuzzy model is used to model this suspension with possible sprung mass variation. The parallel-distributed compensation (PDC) scheme is deployed to derive a fault-tolerant fuzzy controller for the T-S fuzzy suspension model. In order to reduce the motor wear caused by the dynamic force transmitted to the in-wheel motor, the dynamic force is taken as an additional controlled output besides the traditional optimization objectives such as sprung mass acceleration, suspension deflection and actuator saturation. The H∞ performance of the proposed controller is derived as linear matrix inequalities (LMIs) comprising three equality constraints which are solved efficiently by means of MATLAB LMI Toolbox. The proposed controller is applied to an electric vehicle suspension and its effectiveness is demonstrated through computer simulation.

  1. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan

    2016-05-18

    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  2. Characterization of the High-Speed-Stage Bearing Skidding of Wind Turbine Gearboxes Induced by Dynamic Electricity Grid Events

    Energy Technology Data Exchange (ETDEWEB)

    Helsen, Jan; Guillaume, Patrick; Guo, Yi; Keller, Jonathan

    2016-07-01

    Bearing behavior is an important factor for wind turbine drivetrain reliability. Extreme loads and dynamic excitations pose challenges to the bearing design and therefore its performance. Excessive skidding of the bearing rollers should be avoided because it can cause scuffing failures. Excitations coming from wind and the electricity grid can subject the drivetrain to fluctuating torque and nontorque loads. Wind-induced excitations have been investigated predominantly in literature. However, modern wind turbines are subjected more and more to grid-induced loads because of stricter electricity grid regulations. For example, during fault-ride-through events, turbines are required to stay connected for a longer period of time during the grid failure. This work investigates the influence of electrically induced excitations on the skidding behaviour of the tapered roller bearings on the high-speed stage of a wind turbine gearbox. This skidding behaviour during dynamic events is described as a potential bearing failure initiator by many researchers; however, only limited full-scale dynamic testing is documented. Therefore, a dedicated gridloss-type event is defined in the paper and conducted in a dynamometer test on a full-scale wind turbine nacelle. During the event, a complete electricity grid failure is simulated while the turbine is at rated speed and predefined torque levels. Particular focus is on the characterization of the high-speed shaft tapered roller bearing slip behavior. Strain-gauge bridges in grooves along the circumference of the outer ring are used to characterize the bearing load zone in detail. It is shown that during the torque reversals of the transient event, roller slip can be induced. This indicates the potential of the applied load case to go beyond the preload of the tapered roller bearing. Furthermore, the relation between the applied torque and skidding level is studied.

  3. Dynamical properties for the problem of a particle in an electric field of wave packet: Low velocity and relativistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Diego F.M., E-mail: diegofregolente@gmail.com [Institute for Multiscale Simulations, Friedrich-Alexander Universität, D-91052, Erlangen (Germany); Leonel, Edson D., E-mail: edleonel@rc.unesp.br [Departamento de Estatística, Matemática Aplicada e Computação, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); Departamento de Física, UNESP, Univ. Estadual Paulista, Av. 24A, 1515, 13506-900, Rio Claro, SP (Brazil)

    2012-11-01

    We study some dynamical properties for the problem of a charged particle in an electric field considering both the low velocity and relativistic cases. The dynamics for both approaches is described in terms of a two-dimensional and nonlinear mapping. The structure of the phase spaces is mixed and we introduce a hole in the chaotic sea to let the particles to escape. By changing the size of the hole we show that the survival probability decays exponentially for both cases. Additionally, we show for the relativistic dynamics, that the introduction of dissipation changes the mixed phase space and attractors appear. We study the parameter space by using the Lyapunov exponent and the average energy over the orbit and show that the system has a very rich structure with infinite family of self-similar shrimp shaped embedded in a chaotic region.

  4. Effect of applying static electric field on the physical parameters and dynamics of laser-induced plasma

    Directory of Open Access Journals (Sweden)

    Asmaa Elhassan

    2010-04-01

    Full Text Available In order to improve the performance of the LIBS technique – in particular its sensitivity, reproducibility and limit of detection – we studied the effect of applying a static electric field with different polarities on the emission spectra obtained in a typical LIBS set-up. The physical parameters of the laser-induced plasma, namely the electron density Ne and the plasma temperature Te, were studied under such circumstances. In addition to the spectroscopic analysis of the plasma plume emission, the laser-induced shock waves were exploited to monitor the probable changes in the plasma plume dynamics due to the application of the electric field. The study showed a pronounced enhancement in the signal-to-noise (S/N ratio of different Al, neutral and ionic lines under forward biasing voltage (negative target and positive electrode. On the other hand, a clear deterioration of the emission line intensities was observed under conditions of reversed polarity. This negative effect may be attributed to the reduction in electron-ion recombinations due to the stretched plasma plume. The plasma temperature showed a constant value in the average with the increasing electric field in both directions. This effect may be due to the fact that the measured values of Te were averaged over the whole plasma emission volume. The electron density was observed to decrease slightly in the case of forward biasing while no significant effect was noticed in the case of reversed biasing. This slight decrease in Ne can be interpreted in view of the increase in the rate of electron–ion recombinations due to the presence of the electric field. No appreciable effects of the applied electric field on the plasma dynamics were noticed.

  5. Recent advances in understanding provoked vestibulodynia [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Ahinoam Lev-Sagie

    2016-10-01

    Full Text Available Vulvodynia refers to pain in the vulva of at least 3 months’ duration in the absence of a recognized underlying cause. Provoked, localized vestibulodynia is the term used to describe superficial pain confined to the vulvar vestibule, provoked by touch. This review will focus on provoked vestibulodynia with regard to its suggested causative factors and will discuss the role of inflammation, vulvovaginal infections, mucosal nerve fiber proliferation, hormonal associations, central pain mechanisms, pelvic floor muscle dysfunction, and genetic factors. Clinical observations, epidemiological studies, and data from basic research emphasize the heterogeneity of vulvar pain syndromes. There is a critical need to perform prospective, longitudinal studies that will allow better diagnostic criteria and subgrouping of patients that would lead to improvements in our understanding of provoked vestibulodynia and its treatment.

  6. Communication: Influence of external static and alternating electric fields on water from long-time non-equilibrium ab initio molecular dynamics

    Science.gov (United States)

    Futera, Zdenek; English, Niall J.

    2017-07-01

    The response of water to externally applied electric fields is of central relevance in the modern world, where many extraneous electric fields are ubiquitous. Historically, the application of external fields in non-equilibrium molecular dynamics has been restricted, by and large, to relatively inexpensive, more or less sophisticated, empirical models. Here, we report long-time non-equilibrium ab initio molecular dynamics in both static and oscillating (time-dependent) external electric fields, therefore opening up a new vista in rigorous studies of electric-field effects on dynamical systems with the full arsenal of electronic-structure methods. In so doing, we apply this to liquid water with state-of-the-art non-local treatment of dispersion, and we compute a range of field effects on structural and dynamical properties, such as diffusivities and hydrogen-bond kinetics.

  7. A weak electric field-assisted ultrafast electrical switching dynamics in In3SbTe2 phase-change memory devices

    Directory of Open Access Journals (Sweden)

    Shivendra Kumar Pandey

    2017-07-01

    Full Text Available Prefixing a weak electric field (incubation might enhance the crystallization speed via pre-structural ordering and thereby achieving faster programming of phase change memory (PCM devices. We employed a weak electric field, equivalent to a constant small voltage (that is incubation voltage, Vi of 0.3 V to the applied voltage pulse, VA (main pulse for a systematic understanding of voltage-dependent rapid threshold switching characteristics and crystallization (set process of In3SbTe2 (IST PCM devices. Our experimental results on incubation-assisted switching elucidate strikingly one order faster threshold switching, with an extremely small delay time, td of 300 ps, as compared with no incubation voltage (Vi = 0 V for the same VA. Also, the voltage dependent characteristics of incubation-assisted switching dynamics confirm that the initiation of threshold switching occurs at a lower voltage of 0.82 times of VA. Furthermore, we demonstrate an incubation assisted ultrafast set process of IST device for a low VA of 1.7 V (∼18 % lesser compared to without incubation within a short pulse-width of 1.5 ns (full width half maximum, FWHM. These findings of ultrafast switching, yet low power set process would immensely be helpful towards designing high speed PCM devices with low power operation.

  8. Grid integration and smart grid implementation of emerging technologies in electric power systems through approximate dynamic programming

    Science.gov (United States)

    Xiao, Jingjie

    A key hurdle for implementing real-time pricing of electricity is a lack of consumers' responses. Solutions to overcome the hurdle include the energy management system that automatically optimizes household appliance usage such as plug-in hybrid electric vehicle charging (and discharging with vehicle-to-grid) via a two-way communication with the grid. Real-time pricing, combined with household automation devices, has a potential to accommodate an increasing penetration of plug-in hybrid electric vehicles. In addition, the intelligent energy controller on the consumer-side can help increase the utilization rate of the intermittent renewable resource, as the demand can be managed to match the output profile of renewables, thus making the intermittent resource such as wind and solar more economically competitive in the long run. One of the main goals of this dissertation is to present how real-time retail pricing, aided by control automation devices, can be integrated into the wholesale electricity market under various uncertainties through approximate dynamic programming. What distinguishes this study from the existing work in the literature is that whole- sale electricity prices are endogenously determined as we solve a system operator's economic dispatch problem on an hourly basis over the entire optimization horizon. This modeling and algorithm framework will allow a feedback loop between electricity prices and electricity consumption to be fully captured. While we are interested in a near-optimal solution using approximate dynamic programming; deterministic linear programming benchmarks are use to demonstrate the quality of our solutions. The other goal of the dissertation is to use this framework to provide numerical evidence to the debate on whether real-time pricing is superior than the current flat rate structure in terms of both economic and environmental impacts. For this purpose, the modeling and algorithm framework is tested on a large-scale test case

  9. A Dynamic Model of the Combined Electricity and Natural Gas Markets

    DEFF Research Database (Denmark)

    Jenkins, Sandra; Annaswamy, Anuradha M.; Hansen, Jacob

    2015-01-01

    With the shale gas revolution, coal retirements, environmental regulations, and increasing renewable energy resources, the interdependency of natural gas and electricity has grown significantly. Interdependency challenges, such as mismatched market schedules and disparate market operations, requi...

  10. Electricity Pricing Mechanism in a Sustainable Environment: A Review and a System Dynamics Modeling Approach

    OpenAIRE

    Tziogas, C; Georgiadis, P; Tsolakis, N; Yakinthos, C

    2017-01-01

    Electricity is an undisputed factor supporting human development, while further supporting social wellbeing and fostering economic growth of modern societies. Therefore, the electricity market provides a vivid policy-making arena for the EU regulators, where on-going structural reforms are promoted with the aim to encapsulate and accommodate sustainability aspects. Notably, the EU Member States have adopted the strategic roadmap “Europe 2020” toward reducing greenhouse gas emissions and energ...

  11. Mild Hybrid Electric Vehicles: Powertrain Optimization for Energy Consumption, Driveability and Vehicle Dynamics Enhancements

    OpenAIRE

    Castellazzi, Luca

    2017-01-01

    This thesis deals with the modeling, the design and the control of mild hybrid electric vehicles. The main goal is to develop accurate design tools and methodologies for preliminary system and component level analysis. Particular attention is devoted to the configuration in which an electric machine is mounted on the rear axle of a passenger car. The use of such a machine in parallel with the internal combustion engine allows one to exploit different functionalities that are able to reduce th...

  12. Molecular orientation via a dynamically induced pulse-train: Wave packet dynamics of NaI in a static electric field

    DEFF Research Database (Denmark)

    Marquetand, P.; Materny, A.; Henriksen, Niels Engholm

    2004-01-01

    We regard the rovibrational wave packet dynamics of NaI in a static electric field after femtosecond excitation to its first electronically excited state. The following quasibound nuclear wave packet motion is accompanied by a bonding situation changing from covalent to ionic. At times when...... the charge separation is present, i.e., when the bond-length is large, a strong dipole moment exists and rotational excitation takes place. Upon bond contraction, the then covalently bound molecule does not experience the external field. This scenario repeats itself periodically. Thus, the vibrational...

  13. Dynamics of competing diffusion processes in a bias electric field: kinetic Ising model approach and phenomenological descriptions

    CERN Document Server

    Aldrin-Denny, R

    1998-01-01

    The methodology of formulating spatio-temporal diffusion-migration equations in an applied electric field for two competing diffusion processes is outlined using kinetic Ising model versions with the help of spin-exchange dynamics due to Kawasaki. The two transport processes considered here correspond to bounded displacement of species attached to supramolecular structures and electron hopping between spatially separated electron transfer active centres. The dependence of the diffusion coefficient on number density as well as the microscopic basis underlying phenomenological diffusion-migration equations are pointed out. (author)

  14. The effect of thermal fluctuations on Holstein polaron dynamics in electric field

    Science.gov (United States)

    Voulgarakis, Nikolaos K.

    2017-08-01

    In this work, we have studied the effects of thermal fluctuations on the stability of polaron motion under the influence of an external electric field. Zero temperature calculations have been reported previously showing the existence of critical electric field, Ecr, where the system transitions from a stable polaron motion to a Bloch-like oscillation. In this study, we further report that for intermediate polaron sizes the lifetime of such Bloch-like oscillations decay with time due to excessive phonon emission. Our numerical simulations show that the value of Ecr is finite for small temperatures. However, Ecr rapidly decreases with increasing T and becomes practically zero for T > Tcr. In this small but finite temperature window, we report how temperature affects (a) the electric current density, and (b) the Bloch-like frequencies.

  15. Utilization of surplus electricity from wind power for dynamic biogas upgrading

    DEFF Research Database (Denmark)

    Jurgensen, Lars; Ehimen, Ehiazesebhor Augustine; Born, Jens

    2014-01-01

    The methanation of CO2 has been increasingly discussed for the potential long term storage of electricity and for facilitating grid load management. Using the regions of northern Germany as a case study, the feasibility of CO2 conversion from biogas plants and its integration in existing natural...... gas grid was examined in this study. Furthermore the material and energy flows of in the methanation process, were evaluated to provide expression for the quantities of excess electrical energy which could be potentially stored using the biogas integrated systems. The study results showed...... that with 480 biogas plants in the region would be able to utilize up to 0.7 TWh surplus electricity could be used to produce 100 106 m3 at standard temperature and pressure of upgraded methane per year....

  16. A thermal and electrical dynamic mathematical model for squirrel cage induction motors; Modelamento matematico dinamico termico e eletrico de motores de inducao

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Ronaldo Martins de

    1996-01-01

    A thermal and electrical dynamic mathematical model for squirrel cage induction motors is presented. The electrical model is described by Park equation and the torque equation, while the thermal model is described by a system of four first order differential equations that represent the motor heat transfer process. The model presented can be used to determine thermal and electrical performance for any operation condition. However, it is suitable mainly for machines operating under continuously transient condition. The presented mathematical model also incorporate variation of rotor winding electrical parameters due to skin effect. (author)

  17. The dynamics of technology diffusion and the impacts of climate policy instruments in the decarbonisation of the global electricity sector

    CERN Document Server

    Mercure, J -F; Foley, A M; Chewpreecha, U; Pollitt, H

    2013-01-01

    This paper presents an analysis of possible uses of climate policy instruments for the decarbonisation of the global electricity sector in a non-equilibrium economic and technology innovation-diffusion perspective. Emissions reductions occur through changes in technology and energy consumption; in this context, investment decision-making opportunities occur periodically, which energy policy can incentivise in order to transform energy systems and meet reductions targets. Energy markets are driven by innovation, dynamic costs and technology diffusion; yet, the incumbent systems optimisation methodology in energy modelling does not address these aspects nor the effectiveness of policy onto decision-making since the dynamics modelled take their source from the top-down `social-planner' assumption. This leads to an underestimation of strong technology lock-ins in cost-optimal scenarios of technology. Our approach explores the global diffusion of low carbon technology in connection to a highly disaggregated sector...

  18. Population Dynamics for Renewables in Electricity Markets: A Minority Game View

    DEFF Research Database (Denmark)

    Papakonstantinou, Athanasios; Pinson, Pierre

    2016-01-01

    The dominance of fluctuating and intermittent stochastic renewable energy sources (RES) has introduced uncertainty in power systems which in turn, has challenged how electricity market operate. In this context, there has been significant research in developing strategies for RES producers, which...... however typically focuses on the decision process of a single producer, assuming unrealistic access to aspects of information about the power system. This paper analyzes the behavior of an entire population of stochastic producers in an electricity market using as basis a minority game: the El Farol Bar...

  19. Dynamic Assessment of COTS Converters-based DC Integrated Power Systems in Electric Ships

    DEFF Research Database (Denmark)

    Francés, Airán; Anvari-Moghaddam, Amjad; Diaz, Enrique Rodriguez

    2018-01-01

    Maritime applications have found in the integration of the electric power system a way to further improve efficiency and reduce the weight of new electric ships. This movement has led scientists to integrate smart management systems to optimize the overall behavior of the grid. In this context......, power electronics play a key role in linking the different elements of the power architecture. Moreover, the transition towards a dc distribution, which has already been established in other applications, is being regarded as a promising alternative to ease the integration of renewable sources...

  20. Dynamically Harmonized FT-ICR Cell with Specially Shaped Electrodes for Compensation of Inhomogeneity of the Magnetic Field. Computer Simulations of the Electric Field and Ion Motion Dynamics

    Science.gov (United States)

    Kostyukevich, Yury I.; Vladimirov, Gleb N.; Nikolaev, Eugene N.

    2012-12-01

    The recently introduced ion trap for FT-ICR mass spectrometers with dynamic harmonization showed the highest resolving power ever achieved both for ions with moderate masses 500-1000 Da (peptides) as well as ions with very high masses of up to 200 kDa (proteins). Such results were obtained for superconducting magnets of very high homogeneity of the magnetic field. For magnets with lower homogeneity, the time of transient duration would be smaller. In superconducting magnets used in FT-ICR mass spectrometry the inhomogeneity of the magnetic field in its axial direction prevails over the inhomogeneity in other directions and should be considered as the main factor influencing the synchronic motion of the ion cloud. The inhomogeneity leads to a dependence of the cyclotron frequency from the amplitude of axial oscillation in the potential well of the ion trap. As a consequence, ions in an ion cloud become dephased, which leads to signal attenuation and decrease in the resolving power. Ion cyclotron frequency is also affected by the radial component of the electric field. Hence, by appropriately adjusting the electric field one can compensate the inhomogeneity of the magnetic field and align the cyclotron frequency in the whole range of amplitudes of z-oscillations. A method of magnetic field inhomogeneity compensation in a dynamically harmonized FT-ICR cell is presented, based on adding of extra electrodes into the cell shaped in such a way that the averaged electric field created by these electrodes produces a counter force to the forces caused by the inhomogeneous magnetic field.

  1. Internal derangement as a predictor of provoked pain on mouth opening: A magnetic resonance imaging study

    Science.gov (United States)

    Park, Ha-Na; Kim, Kyoung-A

    2017-01-01

    Purpose This study investigated the relationship between pain and internal derangement in temporomandibular disorder (TMD) patients using magnetic resonance imaging (MRI). Materials and Methods This study analyzed 356 TMD patients (712 temporomandibular joints [TMJs]). The inclusion criteria were the presence of spontaneous or provoked pain on one or both TMJs and having undergone MRI. The patients with provoked pain were divided into 3 groups: pain on palpation, pain on mouth opening, and pain on mastication. MRI was performed using a 1.5-T scanner. T1- and T2-weighted parasagittal and paracoronal images were obtained. According to the findings on the T1-weighted images, another 3 groups were created based on internal derangement: normal, disc displacement with reduction, and disc displacement without reduction. The MRI findings were independently interpreted by 2 experienced oral and maxillofacial radiologists at 2 different times. Statistical analysis was performed by the chi-square test using SPSS (version 12.0; SPSS Inc., Chicago, IL, USA). Results Provoked pain on mouth opening was found to be correlated with internal derangement in TMD patients (Ppain and provoked pain on palpation or mastication were not associated with internal derangement (P>.05). Conclusion These results suggest that internal derangement was a significant predictor of provoked pain on mouth opening. PMID:29279820

  2. A system dynamics analysis of the Nordic electricity market: The transition from fossil fuelled toward a renewable supply within a liberalized electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Vogstad, Klaus-Ole

    2005-07-01

    A system dynamic model to analyze long-term versus short-term implications of various energy policies within the context of the Nordic electricity market has been developed. The model itself provides a theory of the development of the Nordic electricity market in response to various energy policies, both in the long and the short term. The model includes generation scheduling, demand, price formation, investment decisions, resource availability and to some extent technology progress as endogenous. Thus, explanations of the model behaviour can be found from within the model. As examples of use, the model/modelling concept addresses two important questions on the energy policy agenda. First the marginal C02-emission controversy has been study, whether building gas power in Norway increase or reduce Nordic C02-emissions. The results were that in the short run, some emission reductions can be obtained due to substitution of existing coal units by operations of the market, but this effect was found to be modest. Existing gas power is also substituted, plus some bio. In the long run, there are also some investment substitutions of renewables. These effects do not appear to be significant in the short run, but in the long run, the investment rate of renewables is reduced as a consequence of reduced prices from gas. The reduced investments in renewables results in increased emissions. Some increase in demand is also to be expected from adding gas power, due to price-elasticity of demand. The net result is that gas power is likely to increase C02-emissions, which contradicts the current belief as well as results from other electricity market models that omit the long-term mechanisms such as investment decisions and technology progress. The second study analyzed the current Swedish TGC market at the time of the introduction. The purpose was to assist market design. It was found that the current Swedish TGC market design is likely to crash, due to the slow adjustment of the

  3. Electric field effects on the dynamics of bubble detachment from an inclined surface

    Science.gov (United States)

    Di Marco, P.; Morganti, N.; Saccone, G.

    2015-11-01

    An experimental apparatus to study bubble detachment from an inclined surface under the action of electric forces is described. It consists of a container filled with FC72 at room temperature and pressure where a train of gas bubbles is injected from an orifice. An electrostatic field can be imposed around the bubble, while the cell can be tilted from 0 to 90°. It is possible to study interface growth with the aid of high-speed cinematography. Since the interface is asymmetrical, a mirror system allowed to acquire, in the same frame, two images at 90° of the bubble. Different inclinations, injection rates and voltages were tested in order to couple the effects of shear gravity and electric field. Curvature and contact angles have been derived with appropriate interpolation methods of the profile. Force balances on the bubble were checked, finding an electric force, which, at first pulls the bubbles from the orifice, then pushes it against the surface. The motion of the center of gravity confirms this behaviour. A power balance has been developed to determine the energy contributions, revealing that surface growth incorporates both the effects of inlet power and electric field.

  4. Dynamic Variation in Pleasure in Children Predicts Nonlinear Change in Lateral Frontal Brain Electrical Activity

    Science.gov (United States)

    Light, Sharee N.; Coan, James A.; Frye, Corrina; Goldsmith, H. Hill; Davidson, Richard J.

    2009-01-01

    Individual variation in the experience and expression of pleasure may relate to differential patterns of lateral frontal activity. Brain electrical measures have been used to study the asymmetric involvement of lateral frontal cortex in positive emotion, but the excellent time resolution of these measures has not been used to capture…

  5. Modeling and experimental investigation of thermal-mechanical-electric coupling dynamics in a standing wave ultrasonic motor

    Science.gov (United States)

    Li, Xiang; Yao, Zhiyuan; He, Yigang; Dai, Shichao

    2017-09-01

    Ultrasonic motor operation relies on high-frequency vibration of a piezoelectric vibrator and interface friction between the stator and rotor/slider, which can cause temperature rise of the motor under continuous operation, and can affect motor parameters and performance in turn. In this paper, an integral model is developed to study the thermal-mechanical-electric coupling dynamics in a typical standing wave ultrasonic motor. Stick-slip motion at the contact interface and the temperature dependence of material parameters of the stator are taken into account in this model. The elastic, piezoelectric and dielectric material coefficients of the piezoelectric ceramic, as a function of temperature, are determined experimentally using a resonance method. The critical parameters in the model are identified via measured results. The resulting model can be used to evaluate the variation in output characteristics of the motor caused by the thermal-mechanical-electric coupling effects. Furthermore, the dynamic temperature rise of the motor can be accurately predicted under different input parameters using the developed model, which will contribute to improving the reliable life of a motor for long-term running.

  6. Optical and electric properties of dynamic holographic gratings with arbitrary contrast

    DEFF Research Database (Denmark)

    Kukhtarev, Nickolai; Buchhave, Preben; Lyuksyutov, Sergei

    1997-01-01

    An analytical solution of the photoconductive material equations for dynamic holographic gratings of arbitrary contrast has been obtained. A method of measuring high-contrast correlation functions has been suggested and tested experimentally. Good agreement with the analytical expression for the ......An analytical solution of the photoconductive material equations for dynamic holographic gratings of arbitrary contrast has been obtained. A method of measuring high-contrast correlation functions has been suggested and tested experimentally. Good agreement with the analytical expression...

  7. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  8. Provokative Elemente einer Didaktik internetgestützter Lehr-Lernarrangements

    Directory of Open Access Journals (Sweden)

    Wolfgang Müskens

    2002-10-01

    Full Text Available Onlinebasiertes kollaboratives Lernen erfordert eine neue Rolle der Lehrenden und damit verbunden auch neue didaktische Methoden. Ausgehend vom Begriff der Provokation wird eine solche Didaktik in Abgrenzung zur Vorstellung eines ausschliesslich selbstgesteuerten Lernens entwickelt. Provokation wird in diesem Zusammenhang als die intendierte Konfrontation eines Lernenden mit einstellungskonträrem Material verstanden. Die Grundlagen der hier vorgestellten Didaktik werden aus einer Vielzahl theoretischer Wurzeln und empirischer Forschungsergebnisse hergeleitet: Es wird auf die Beziehung zum Kompetenzbegriff, zur Systemtheorie, zur Emotionspsychologie, zur Induzierung kognitiver Konflikte, zur Dissonanztheorie und zu Kellys Theorie der persönlichen Konstrukte eingegangen. Als konkrete Methoden der provokativen Didaktik für das E-Learning werden u. a. provokative Statements, das Induzieren einstellungskonträrer Perspektiven und eine an die «Fixed-Role-Therapy» angelehnte Aufgabenstellung diskutiert. Die Methoden der provokativen Didaktik bedeuten eine hochgradige Individualisierung des Lernens und eine Intensivierung des Verhältnisses zwischen Lerner und Lehrendem.

  9. Intrusions and provoked and spontaneous confabulations on memory tests in Korsakoff's syndrome.

    Science.gov (United States)

    Rensen, Yvonne C M; Oosterman, Joukje M; Walvoort, Serge J W; Eling, Paul A T M; Kessels, Roy P C

    2017-03-01

    Intrusions on verbal memory tests have been used as an index for clinical confabulation. Severe memory impairments in combination with executive dysfunction have been suggested to be the underlying mechanism of confabulation, but to date, this relation is unclear. The aim of this study was (a) to examine the relation between (different types of) intrusions and confabulations in a large sample of confabulating patients with Korsakoff's syndrome (KS) and (b) to investigate whether different measures of executive functioning and memory performance are related to provoked and spontaneous confabulation. The Dutch version of the California Verbal Learning Test (CVLT) and various executive function and memory tests were administered to a group of 51 confabulating patients with KS. Professional caregivers rated the severity of provoked and spontaneous confabulation behavior of the patients using the Nijmegen-Venray Confabulation List-20 (NVCL-20). The total number of intrusions on the CVLT was not related to either provoked or spontaneous confabulation scores. None of the CVLT intrusion scores correlated significantly with any of the confabulation scores, but we did find small-to-medium, positive correlations between unrelated intrusions and both provoked confabulations and spontaneous confabulation. Provoked confabulation behavior was associated with executive dysfunction and poorer memory performances. Spontaneous confabulation was not related to performance on measures of executive function and memory. The total number of intrusions on verbal memory tests and clinical confabulations appear to be different phenomena. Only unrelated intrusions produced on the CVLT might possibly be related to confabulations. The production of provoked, but not spontaneous, confabulation is associated with executive dysfunction and memory deficits.

  10. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater-surface water exchange

    Science.gov (United States)

    Steelman, Colby M.; Kennedy, Celia S.; Capes, Donovan C.; Parker, Beth L.

    2017-06-01

    Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater-surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater-surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze-thaw cycle. Surface electromagnetic induction (EMI) and electrical resistivity tomography (ERT) methods captured conditions beneath the riverbed along a pool-riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle) and dominant surficial rock properties (competent versus weathered rock rubble surface). While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river ice during the winter season

  11. What Institutional Dynamics Guide Waste Electrical and Electronic Equipment Refurbishment and Reuse in Urban China?

    OpenAIRE

    Steuer, Benjamin

    2016-01-01

    For over two decades China has faced a veritable e-waste challenge due to the continuous increase in quantities of Waste Electrical and Electronic Equipment (WEEE) coming from foreign and domestic sources. Over more than a decade, the government’s response has been focussed on developing large-scale recycling facilities so as to recover the valuable materials within WEEE. Simultaneously, China is home to a vast, informal segment, which engages in the collection, refurbishment, and processing ...

  12. Electric-field-driven domain wall dynamics in perpendicularly magnetized multilayers

    OpenAIRE

    González, Diego López; Shirahata, Yasuhiro; Van de Wiele, Ben; Franke, Kévin J. A.; Casiraghi, Arianna; Taniyama, Tomoyasu; van Dijken, Sebastiaan

    2017-01-01

    We report on reversible electric-field-driven magnetic domain wall motion in a Cu/Ni multilayer on a ferroelectric BaTiO3 substrate. In our heterostructure, strain-coupling to ferroelastic domains with in-plane and perpendicular polarization in the BaTiO3 substrate causes the formation of domains with perpendicular and in-plane magnetic anisotropy, respectively, in the Cu/Ni multilayer. Walls that separate magnetic domains are...

  13. A Nonlinear Dynamics-Based Estimator for Functional Electrical Stimulation: Preliminary Results from Lower-Leg Extension Experiments.

    Science.gov (United States)

    Allen, Marcus; Zhong, Qiang; Kirsch, Nicholas; Dani, Ashwin; Clark, William W; Sharma, Nitin

    2017-09-07

    Miniature inertial measurement units (IMUs) are wearable sensors that measure limb segment or joint angles during dynamic movements. However, IMUs are generally prone to drift, external magnetic interference, and measurement noise. This paper presents a new class of nonlinear state estimation technique called state-dependent coefficient (SDC) estimation to accurately predict joint angles from IMU measurements. The SDC estimation method uses limb dynamics, instead of limb kinematics, to estimate the limb state. Importantly, the nonlinear limb dynamic model is formulated into state dependent matrices that facilitate the estimator design without performing a Jacobian linearization. The estimation method is experimentally demonstrated to predict knee joint angle measurements during functional electrical stimulation of the quadriceps muscle. The nonlinear knee musculoskeletal model was identified through a series of experiments. The SDC estimator was then compared to an Extended Kalman filter (EKF), which uses a Jacobian linearization and a rotation matrix method, which uses a kinematic model instead of the dynamic model. Each estimator's performance was evaluated against the true value of the joint angle, which was measured through a rotary encoder. The experimental results showed that the SDC estimator, the rotation matrix method, and EKF had root mean square errors of 2.70°, 2.86°, and 4.42°, respectively. Our preliminary experimental results show the new estimator's advantage over the EKF method but a slight advantage over the rotation matrix method. However, the information from the dynamic model allows the SDC method to use only one IMU to measure the knee angle compared to the rotation matrix method that uses 2 IMUs to estimate the angle.

  14. Relativistic point dynamics general equations, constant proper masses, interactions between electric charges, variable proper masses, collisions

    CERN Document Server

    Arzeliès, Henri

    1972-01-01

    Relativistic Point Dynamics focuses on the principles of relativistic dynamics. The book first discusses fundamental equations. The impulse postulate and its consequences and the kinetic energy theorem are then explained. The text also touches on the transformation of main quantities and relativistic decomposition of force, and then discusses fields of force derivable from scalar potentials; fields of force derivable from a scalar potential and a vector potential; and equations of motion. Other concerns include equations for fields; transfer of the equations obtained by variational methods int

  15. Vibration properties of and power harvested by a system of electromagnetic vibration energy harvesters that have electrical dynamics

    Science.gov (United States)

    Cooley, Christopher G.

    2017-09-01

    This study investigates the vibration and dynamic response of a system of coupled electromagnetic vibration energy harvesting devices that each consist of a proof mass, elastic structure, electromagnetic generator, and energy harvesting circuit with inductance, resistance, and capacitance. The governing equations for the coupled electromechanical system are derived using Newtonian mechanics and Kirchhoff circuit laws for an arbitrary number of these subsystems. The equations are cast in matrix operator form to expose the device's vibration properties. The device's complex-valued eigenvalues and eigenvectors are related to physical characteristics of its vibration. Because the electrical circuit has dynamics, these devices have more natural frequencies than typical electromagnetic vibration energy harvesters that have purely resistive circuits. Closed-form expressions for the steady state dynamic response and average power harvested are derived for devices with a single subsystem. Example numerical results for single and double subsystem devices show that the natural frequencies and vibration modes obtained from the eigenvalue problem agree with the resonance locations and response amplitudes obtained independently from forced response calculations. This agreement demonstrates the usefulness of solving eigenvalue problems for these devices. The average power harvested by the device differs substantially at each resonance. Devices with multiple subsystems have multiple modes where large amounts of power are harvested.

  16. Dynamic Power Dispatch Considering Electric Vehicles and Wind Power Using Decomposition Based Multi-Objective Evolutionary Algorithm

    Directory of Open Access Journals (Sweden)

    Boyang Qu

    2017-12-01

    Full Text Available The intermittency of wind power and the large-scale integration of electric vehicles (EVs bring new challenges to the reliability and economy of power system dispatching. In this paper, a novel multi-objective dynamic economic emission dispatch (DEED model is proposed considering the EVs and uncertainties of wind power. The total fuel cost and pollutant emission are considered as the optimization objectives, and the vehicle to grid (V2G power and the conventional generator output power are set as the decision variables. The stochastic wind power is derived by Weibull probability distribution function. Under the premise of meeting the system energy and user’s travel demand, the charging and discharging behavior of the EVs are dynamically managed. Moreover, we propose a two-step dynamic constraint processing strategy for decision variables based on penalty function, and, on this basis, the Multi-Objective Evolutionary Algorithm Based on Decomposition (MOEA/D algorithm is improved. The proposed model and approach are verified by the 10-generator system. The results demonstrate that the proposed DEED model and the improved MOEA/D algorithm are effective and reasonable.

  17. A Novel Nonlinear Optimal Control Approach for the Dynamic Process of a Hybrid Electric Vehicle Equipped with Electromechanical Transmission

    Directory of Open Access Journals (Sweden)

    Changle Xiang

    2015-01-01

    Full Text Available Coordinatively controlling the engine and several motor/generators (MGs during a dynamic process is a challenging problem because they are coupled together by the electromechanical transmission (EMT system and all of them have strong nonlinear characteristics. We develop a novel nonlinear optimal control approach based on the multiobjective dynamic optimization model of the hybrid electric vehicle (HEV, which is equipped with an EMT system. In this approach, the current states of the components are obtained by using the state observation algorithm based on Kalman filtering; the future states of the components and the feasible region of the control variables are estimated by using the dynamic prediction algorithm based on the nonlinear model of the EMT system. Then, the control variables are achieved by using the optimal decision algorithm based on the hierarchical optimization and nonlinear programming, and the influence of the model error and the external disturbance are modified by using the feedback compensation algorithm. The simulation results illustrate the efficiency of the proposed control approach, and the test results verify its real-time performance.

  18. A study of causality structure and dynamics in industrial electricity consumption based on Granger network

    Science.gov (United States)

    Yao, Can-Zhong; Lin, Ji-Nan; Lin, Qing-Wen; Zheng, Xu-Zhou; Liu, Xiao-Feng

    2016-11-01

    Based on industrial electricity consumption, we model industrial networks by Granger causality method and MST (minimum spanning tree), and then further stick onto an industrial coupling mechanism from energy-consumption perspective. First, we construct Granger causality networks of five provinces in South China of GD, GX, GZ, HN and YN based on their industrial electricity consumption data, and we demonstrate from a network-topology perspective: the distribution of weight of links of all industrial electricity-consumption Granger causality networks approximately follows power-law distribution, revealing a phenomenon that few industries may bring a tremendous influence on the rest. Moreover, correlation analysis between weight and degree of a node shows that in most Granger causality networks, both span and strength of influence of a given industry will significantly increase. Further, we analyze the relationship between the thresholds of Granger causality significance and density of corresponding networks. Results show GD and HN could be classified into a group with relatively greater global differentiation in industries and unbalanced industrial development, however, GX, GZ and YN are grouped as second cluster with relatively balanced industrial development. Furthermore, using Chu-Liu-EdmondsMST algorithm, we extract graphs of MSTs or maximal cliques from industrial electricity-consumption Granger causality networks, and research on energy transmission structure, feedback loop, and bootstrap reliability. By analyzing MSTs, we find that only GD, GX and YN can be extracted with MST graphs, and capture the probable transmission routes of key nodes. Besides we illustrate all three MST graphs are involved with feedback loops structures with various characteristics: GX has complete feed-forward section, feed-back section and feedback loop section; YN has only feed-forward section and feedback loop section; GD has multiple feedback loops section. Finally, we conduct

  19. The Dynamic Analysis of Hydropower House and Unit System in Coupled Hydraulic-mechanical-electric Factors

    Science.gov (United States)

    MA, Z. Y.; Wu, Q. Q.

    2016-11-01

    A hydraulic-mechanical-electric and structures coupled model of hydropower station system including subsystem models of the penstock, hydro-turbine model, speed governor, synchronous generator as well as grid, rotor-bearing system and powerhouse structure is established. This model is used to simulate the small fluctuation transient process of 10% load-up in the part load condition for hydropower station. Mechanical eccentric force, unbalanced magnetic pull and vortex pressure fluctuation at inlet of draft tube are considered in the numerical calculation. The interaction between hydraulic-mechanical-electric coupled factors and structural vibration properties during the small fluctuation transient process is studied. The results indicate that the speed regulation for turbine has very litter impact on the transient process of generator. In the process of small fluctuation with loading method in this paper, structure of powerhouse is greatly influenced by vortex pressure pulse in the draft tube, and the vibration of unit is excited by loads which caused by itself rotating.

  20. Electrical lysis: dynamics revisited and advances in On-chip operation.

    Science.gov (United States)

    Morshed, Bashir; Shams, Maitham; Mussivand, Tofy

    2013-01-01

    Electrical lysis (EL) is the process of breaking the cell membrane to expose the internal contents under an applied high electric field. Lysis is an important phenomenon for cellular analysis, medical treatment, and biofouling control. This paper aims to review, summarize, and analyze recent advancements on EL. Major databases including PubMed, Ei Engineering Village, IEEE Xplore, and Scholars Portal were searched using relevant keywords. More than 50 articles published in English since 1997 are cited in this article. EL has several key advantages compared to other lysis techniques such as chemical, mechanical, sonication, or laser, including rapid speed of operation, ability to control, miniaturization, low cost, and low power requirement. A variety of cell types have been investigated for including protoplasts, E. coli, yeasts, blood cells, and cancer cells. EL has been developed and applied for decontamination, cytology, genetics, single-cell analysis, cancer treatment, and other applications. On-chip EL is a promising technology for multiplexed automated implementation of cell-sample preparation and processing with micro- or nanoliter reagents.

  1. Enhanced Regenerative Braking Strategies for Electric Vehicles: Dynamic Performance and Potential Analysis

    Directory of Open Access Journals (Sweden)

    Boyi Xiao

    2017-11-01

    Full Text Available A regenerative braking system and hydraulic braking system are used in conjunction in the majority of electric vehicles worldwide. We propose a new regenerative braking distribution strategy that is based on multi-input fuzzy control logic while considering the influences of the battery’s state of charge, the brake strength and the motor speed. To verify the braking performance and recovery economy, this strategy was applied to a battery electric vehicle model and compared with two other improved regenerative braking strategies. The performance simulation was performed using standard driving cycles (NEDC, LA92, and JP1015 and a real-world-based urban cycle in China. The tested braking strategies satisfied the general safety requirements of Europe (as specified in ECE-13H, and the emergency braking scenario and economic potential were tested. The simulation results demonstrated the differences in the braking force distribution performance of these three regenerative braking strategies, the feasibility of the braking methods for the proposed driving cycles and the energy economic potential of the three strategies.

  2. Personality and Aggressive Behavior under Provoking and Neutral Conditions: A Meta-Analytic Review

    Science.gov (United States)

    Bettencourt, Ann B.; Talley, Amelia; Benjamin, Arlin James; Valentine, Jeffery

    2006-01-01

    The authors conducted a comprehensive review to understand the relation between personality and aggressive behavior, under provoking and nonprovoking conditions. The qualitative review revealed that some personality variables influenced aggressive behavior under both neutral and provocation conditions, whereas others influenced aggressive…

  3. Acute hypotension induced by aortic clamp vs. PTH provokes distinct proximal tubule Na+ transporter redistribution patterns

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; Lin, Harrison W

    2004-01-01

    in renal cortical membranes fractionated on sorbitol density gradients. Aortic clamp-induced acute hypotension (from 100 +/- 3 to 78 +/- 2 mmHg) provoked a 62% decrease in urine output and a significant decrease in volume flow from the proximal tubule detected as a 66% decrease in endogenous lithium......-density membranes enriched in apical markers. PTH at much lower doses (

  4. Anisocoria in the dog provoked by a toxic contact with an ornamental plant: Datura stramonium.

    Science.gov (United States)

    Hansen, Philippe; Clerc, Bernard

    2002-12-01

    We report an unusual case of anisocoria in the dog provoked by Datura stramonium, and an experimental clinical assay to reproduce the anisocoria using simple contact with part of the plant in four healthy dogs. Any part of the D. stramonium plant produced anisocoria following simple contact with the eye.

  5. MLA Report on Foreign-Language Education Continues to Provoke Debate

    Science.gov (United States)

    Wasley, Paula

    2008-01-01

    This article reports that, nearly one year after its release, the report on foreign language and higher education issued by an ad hoc committee of the Modern Language Association (MLA) is still provoking discussion about reforms in the teaching of foreign languages and the role of the association in any revamp. The debate continued at a panel held…

  6. Dynamic behaviour of a ferro-electric liquid crystal by means of nuclear magnetic resonance and dielectric spectroscopy

    Science.gov (United States)

    Domenici, Valentina; Marini, Alberto; Menicagli, Rita; Veracini, Carlo Alberto; Bubnov, Aleksej M.; Glogarova, Milada

    2007-05-01

    The field of ferroelectric liquid crystals (FLCs) is one of the most fascinating aspects of the Science of Materials for their interesting electro-optic applications. Among different chemical and physical properties those related to the molecular dynamics are very stimulating due to the relationship between molecular motions and macroscopic response to external fields, such as electric and magnetic ones. In this work, the molecular dynamics of a ferroelectric smectogen, namely the (S)-2-methylbutyl-[4'-(4"-heptyloxyphenyl)-benzoyl-4-oxy-(S)-2-((S)-2')-benzoyl)-propionyl)]-propionate (ZLL 7/*) has been investigated by means of 2H NMR and dielectric relaxation techniques. The first method allows us to get information on the molecular motions in the fast motion regime, in particular the diffusion reorientational motions of the whole molecule, as well as of the internal motions affecting the phenyl and biphenyl fragments. The second technique, which covers the slow motion regime, has been used to detect collective motions and fluctuation modes. This study allows us to have a complete idea of molecular motions in the different smectic phases formed by the ZLL 7/* mesogens, in particular the paraelectric smectic A (SmA), the ferroelectric smectic C* (SmC*), the antiferroelectric smectic C* A (SmC* A) and the re-entrant ferroelectric smectic C* (SmC* r) phases. This last phase has been investigated for the first time in this work, from the point of view of the dynamic behaviour. All results will be discussed in the framework of the molecular dynamics of ferroelectric liquid crystals, reported in the literature so far.

  7. Muscle tissue oxygenation, pressure, electrical, and mechanical responses during dynamic and static voluntary contractions

    DEFF Research Database (Denmark)

    Vedsted, Pernille; Blangsted, Anne Katrine; Søgaard, Karen

    2006-01-01

    Dynamic muscle contractions have been shown to cause greater energy turnover and fatigue than static contractions performed at a corresponding force level. Therefore, we hypothesized that: (1) electro- (EMG) and mechanomyography (MMG), intramuscular pressure (IMP), and reduction in muscle oxygen...... similar in spite of major differences in the MMG and EMG responses of the muscle during contraction periods. This may relate to the surprisingly lower IMP in DYN than IST....

  8. SIMULATION OF THE ELECTRIC DRIVE DYNAMICS ON THE BASIS OF ROOT LOCUS MODEL

    Directory of Open Access Journals (Sweden)

    A. A. Nesenchuk

    2016-01-01

    Full Text Available The paper represents the task of simulation of the control system dynamics in the rotor flux oriented vector control system of the induction motor with application of the mathematical model in the form of the extended root locus. An algorithm for control system parameters calculation has been proposed, ensuring stability and required quality when operating in conditions of the plant parametric uncertainty.

  9. External electric field effects on the mechanical properties of the αβ-tubulin dimer of microtubules: a molecular dynamics study.

    Science.gov (United States)

    Saeidi, H R; Lohrasebi, A; Mahnam, K

    2014-08-01

    The mechanical properties of the αβ-tubulin dimer of microtubules was modeled by using the molecular dynamics (MD) simulation method. The effect on the mechanical properties of the dimer of the existence and nonexistence of an applied electric field, either constant or periodic, was studied. Since there are charged or polar groups in the dimer structure, the electric field can interact with the dimer. The elastic constant and Young's modulus of the dimer were decreased when the dimer was exposed to a constant electric field of 0.03 V/nm. Furthermore, applying an oscillating electric field in the 1 GHz range to the dimer increased the elastic constant and Young's modulus of the dimer. These parameters were related to dimer rigidity and, consequently, in this frequency range, the application of electric fields may affect the function of microtubules.

  10. Nonequilibrium molecular dynamics study of electric and low-frequency microwave fields on hen egg white lysozyme.

    Science.gov (United States)

    English, Niall J; Solomentsev, Gleb Y; O'Brien, Paul

    2009-07-21

    Nonequilibrium molecular dynamics simulations of various mutants of hen egg white lysozyme have been performed at 300 K and 1 bar in the presence of both external static electric and low-frequency microwave (2.45 GHz) fields of varying intensity. Significant nonthermal field effects were noted, such as marked changes in the protein's secondary structure relative to the zero-field state, depending on the field conditions, mutation, and orientation with respect to the applied field. This occurred primarily as a consequence of alignment of the protein's total dipole moment with the external field, although the dipolar alignment of water molecules in both the solvation layer and the bulk was also found to be influential. Substantial differences in behavior were found for proteins with and without overall net charges, particularly with respect to translational motion. Localized motion and perturbation of hydrogen bonds were also found to be evident for charged residues.

  11. Microbial metabolism and dynamic changes in the electrical conductivity of soil solutions - A method for detecting extraterrestrial life

    Science.gov (United States)

    Silverman, M. P.; Munoz, E. F.

    1974-01-01

    Experiments are reported which show that measuring metabolic activity in soil solutions by means of dynamic changes in electrical conductivity, water-soluble Ca, or water-soluble Mg is a feasible life detection method. The addition of 0.5% glucose solutions to 12 different air-dried soils always resulted in increases in all three of these parameters. The kinetics and magnitude of these changes for at least two and usually all three of the parameters over a 14-day period were clearly distinguishable from the changes in heat-sterilized controls or unsterilized controls without added glucose. In general, maximal values were achieved more rapidly under aerobic than under anaerobic incubation.

  12. Review on dynamics control of 4WID-4WIS electric vehicle

    Directory of Open Access Journals (Sweden)

    Xin LAI

    2016-08-01

    Full Text Available The four-wheel independent drive and four-wheel independent steering (4WID-4WIS vehicle has the advantages of short transmission chain, high efficiency, compact structure, and high maneuverability. The kinematics and dynamic control of the 4WID-4WIS vehicle are discussed, then key and difficult problems are refined. The distributed network control system is widely used in the vehicle control system, so that real-time and reliable control under non-ideal network is the research challenges, and hierarchical control method is a hot research topic. For the vehicle dynamics control method, the main research focuses on torque distribution method under one or more optimization objectives, and integrated control which harmonizes multi control subjects has become an important research direction. In order to solve the problem of steering mode static switching of the 4WID-4WIS vehicle, the study on the dynamic switching method based on redundant control degree of freedom is a new research direction.

  13. Dynamic model of Stirling engine crank mechanism with connected electric generator

    Directory of Open Access Journals (Sweden)

    Vlach R.

    2009-06-01

    Full Text Available This paper treats of a numerical dynamic model of Stirling engine crank mechanism. The model is included in the complex model of combined heat and power unit. The unit is composed of the Stirling engine and of attached three-phase synchronous generator. This generator should start the Stirling engine in motor mode as well. It is necessary to combine the crank shaft dynamic model and the complete thermal model of Stirling engine for simulations and analyses of engine run. Our aim is to create a dynamics model which takes into account the parameters of crankshaft, piston rods, pistons, and attached generator. For unit working, the electro-mechanical behaviour of generator is also important. That is why we experimentally verified the parameters of generator. The measured characteristics are used in a complex model of heat and power unit. Moreover, it is also possible to determine the Stirling engine torque by the help of these electro-mechanical characteristics. These values can be used e. g. for determination of optimal engine working point or for unit control.

  14. Creation and evolution of North America's gas and electricity regime: A dynamic example of interdependence

    Science.gov (United States)

    Dukert, Joseph M.

    Growing interdependence of Canada, the United States, and Mexico in production, trade, and consumption of natural gas and electricity during the 1990s produced a new North American functional entity---partly governmental, partly non-governmental, and partly intergovernmental. Cooperation among three dissimilar, jealously sovereign countries has surmounted several shocks (California's flawed energy "deregulation" experiments, Enron's scandal, disagreements over the Kyoto Protocol and the Iraq invasion, soaring energy prices, and economic downturns). Explaining this as an international regime (a system of principles, norms, rules, and decision-making procedures around which actor expectations converge in a given issue area), this work explains the timing of its emergence...and how its self-adjusting nature portends increasing significance. Extensive interviews are augmented by newly obtained U.S. government documents about U.S.-Mexican gas negotiations in the late 1970s---when a regime seemed logical, but when necessary and sufficient conditions were lacking. The North American Free Trade Agreement had to be accompanied by regulatory reforms and some market effects, while the gas and electricity industries converged and electronic developments facilitated exchanges of current and future supplies of gas and/or electricity. Now, mutually beneficial pipeline and powerline connections spur expansion, while backsliding from regime acceptance becomes ever more costly---especially for some regions. This is a "virtual" regime---sensed by those involved with no formal charter beyond NAFTA's vague treatment of energy. It is "metanational"---grounded both within and beyond these nation-states. Operating in accord with varied modes of governance, but also through such modest institutions as the North American Energy Working Group and the North American Commission for Environmental Cooperation, the regime supports differing national energy policy goals for the three countries and

  15. Strong electric fields at a prototypical oxide/water interface probed by ab initio molecular dynamics: MgO(001).

    Science.gov (United States)

    Laporte, Sara; Finocchi, Fabio; Paulatto, Lorenzo; Blanchard, Marc; Balan, Etienne; Guyot, François; Saitta, Antonino Marco

    2015-08-21

    We report a density-functional theory (DFT)-based study of the interface of bulk water with a prototypical oxide surface, MgO(001), and focus our study on the often-overlooked surface electric field. In particular, we observe that the bare MgO(001) surface, although charge-neutral and defectless, has an intense electric field on the Å scale. The MgO(001) surface covered with 1 water monolayer (1 ML) is investigated via a supercell accounting for the experimentally-observed (2 × 3) reconstruction, stable at ambient temperature, and in which two out of six water molecules are dissociated. This 1 ML-hydrated surface is also found to have a high, albeit short-ranged, normal component of the field. Finally, the oxide/water interface is studied via room-temperature ab initio molecular dynamics (AIMD) using 34 H2O molecules between two MgO(001) surfaces. To our best knowledge this is the first AIMD study of the MgO(001)/liquid water interface in which all atoms are treated using DFT and including several layers above the first adsorbed layer. We observe that the surface electric field, averaged over the AIMD trajectories, is still very strong on the fully-wet surface, peaking at about 3 V Å(-1). Even in the presence of bulk-like water, the structure of the first layer in contact with the surface remains similar to the (2 × 3)-reconstructed ice ad-layer on MgO(001). Moreover, we observe proton exchange within the first layer, and between the first and second layers - indeed, the O-O distances close to the surface are found to be distributed towards shorter distances, a property which has been shown to directly promote proton transfer.

  16. Can we use Electrical Resistivity Tomography to measure root zone moisture dynamics in fields with multiple crops?

    Science.gov (United States)

    Garre, S.; Coteur, I.; Wongleecharoen, C.; Diels, J.; Vanderborght, J.

    2012-12-01

    Agriculture on shallow or steep soils in the humid tropics often leads to low resource use efficiency. Contour hedgerow intercropping systems have been proposed to reduce run-off and control soil erosion. However, competition for water and nutrients between crops and associated hedgerows may reduce the overall performance of contour hedgerow systems. Electrical resistivity tomography (ERT) is a valuable technique to assess the distribution and dynamics of soil moisture non-invasively. Root water uptake is a spatially variable and small-scale process, which requires at least decimeter resolution and a high sensitivity in order to be able to monitor changes in time and space. Careful experimental design is of uttermost importance in order to maximize the information content of the ERT survey and to gain insights in the possibilities and limitations of the survey. Virtual experiments in combination with absolute and spatial performance measures provide a way to optimize the information that can be retrieved from an ERT experiment. We used this approach to identify a suitable measurement methodology to monitor water fluxes in a contour hedgerow intercropping system in Ratchaburi province, Thailand. The virtual experiment showed that there are important differences between the tested measurement configurations. We saw that the optimal ERT array was capable of recognizing distinct water depletion zones under the different crops. However, sharp contrasts in the 1-D water depletion profile are smoothened. ERT measurements conducted in Thailand showed that the soils of our experimental plots were very heterogeneous both along the slope as with depth. This observation highlighted some constraints of the ERT method for soil moisture monitoring in the field, such as the difficulty to define a relationship between electrical conductivity and soil moisture in very heterogeneous soils. Nevertheless, the data indeed revealed contrasting water depletion patterns under monocropping

  17. From dynamic measurements of photosynthesis in a living plant to sunlight transformation into electricity.

    Science.gov (United States)

    Flexer, Victoria; Mano, Nicolas

    2010-02-15

    We propose here a new method for the direct and continuous measurement of O(2) and glucose generated during photosynthesis. Our system is based on amperometric enzyme biosensors comprising immobilized redox enzymes (glucose oxidase (GOx) and bilirubin oxidase (BOD)) and redox hydrogels "wiring" the enzyme reaction centers to electrodes. We found that these electrodes, implanted into a living plant, responded in real time to visible light as an external stimulus triggering photosynthesis. They proved to be highly selective and fast enough and may be a valuable tool in understanding photosynthesis kinetics. Furthermore, we demonstrate that with our electrodes we could harvest glucose and O(2) produced during photosynthesis to produce energy, transforming sunlight into electricity in a simple, green, renewable, and sustainable way.

  18. Comment on "Dynamics and properties of waves in a modified Noguchi electrical transmission line".

    Science.gov (United States)

    Kenmogne, Fabien; Yemélé, David; Marquié, Patrick

    2016-09-01

    A recent paper [Phys. Rev. E 91, 022925 (2015)PRESCM1539-375510.1103/PhysRevE.91.022925] presents the derivation of the nonlinear equation modeling envelope waves in a specific case of band passed filter discrete nonlinear electrical transmission line (NLTL), called "A modified Noguchi electrical transmission line" according to the authors. Using the reductive perturbation approach in the semidiscrete approximation, they showed that the modulated waves propagating in this NLTL are described by the ordinary nonlinear Schrödinger (NLS) equation. On the basis of their results, the authors claimed that all previous works on the band passed filter NLTL, which considered the vanishing of the dc component of the signal voltage, are incorrect, and this dc term is nonzero. As a consequence, the dispersion and nonlinearity coefficients of the NLS equation are strongly different from those usually obtained, and they found, according to the sign of the product PQ, the existence of one more region (compared to the work of Marquié et al. [Phys. Rev. E 49, 828 (1994)]PLEEE81063-651X10.1103/PhysRevE.49.828) in the dispersion curve that allows the motion of envelope solitons of higher frequency in the system. In this Comment we provide sufficient theoretical and numerical evidence showing that the evidence obtained by the authors otherwise is due to certain terms missed in their mathematical developments when they derived the NLS equation. Our results also suggest that the previous work of Marquié and co-workers correctly predict the fact that the dc term of the signal voltage does not exist and there exist only two regions in the dispersion curve according to the sign of the product PQ.

  19. An electrically actuated imperfect microbeam: Dynamical integrity for interpreting and predicting the device response

    KAUST Repository

    Ruzziconi, Laura

    2013-02-20

    In this study we deal with a microelectromechanical system (MEMS) and develop a dynamical integrity analysis to interpret and predict the experimental response. The device consists of a clamped-clamped polysilicon microbeam, which is electrostatically and electrodynamically actuated. It has non-negligible imperfections, which are a typical consequence of the microfabrication process. A single-mode reduced-order model is derived and extensive numerical simulations are performed in a neighborhood of the first symmetric natural frequency, via frequency response diagrams and behavior chart. The typical softening behavior is observed and the overall scenario is explored, when both the frequency and the electrodynamic voltage are varied. We show that simulations based on direct numerical integration of the equation of motion in time yield satisfactory agreement with the experimental data. Nevertheless, these theoretical predictions are not completely fulfilled in some aspects. In particular, the range of existence of each attractor is smaller in practice than in the simulations. This is because these theoretical curves represent the ideal limit case where disturbances are absent, which never occurs under realistic conditions. A reliable prediction of the actual (and not only theoretical) range of existence of each attractor is essential in applications. To overcome this discrepancy and extend the results to the practical case where disturbances exist, a dynamical integrity analysis is developed. After introducing dynamical integrity concepts, integrity profiles and integrity charts are drawn. They are able to describe if each attractor is robust enough to tolerate the disturbances. Moreover, they detect the parameter range where each branch can be reliably observed in practice and where, instead, becomes vulnerable, i.e. they provide valuable information to operate the device in safe conditions according to the desired outcome and depending on the expected disturbances

  20. Multistability in an electrically actuated carbon nanotube: A dynamical integrity perspective

    KAUST Repository

    Ruzziconi, Laura

    2013-07-12

    This study deals with a slacked carbon nanotube, which is electrostatically and electrodynamically actuated. After introducing a reduced-order model, we investigate the overall scenario of the device response when both the frequency and the electrodynamic voltage are varied. Extensive numerical simulations are performed. The nanostructure exhibits several competing attractors with different characteristics. We examine the multistability in detail, based on numerical integration of the equation of motion in time, since it leads to a considerable versatility of behavior, which may be desirable in applications. Nevertheless, these results do not take into account the presence of disturbances, which are unavoidable under realistic conditions. To extend them to the practical case where disturbances exist, we develop a dynamical integrity analysis. This is performed via the combined use of several dynamical integrity tools. Analyzing the potential well, we observe that the device may be vulnerable to pull-in considerably before the theoretical inevitable escape. Focusing on the safe range, the main attractors are examined to investigate the practical probability to catch them and the practical disappearance of the main ones. Special attention is devoted to the practical final response, to detect where the safe jump to another attractor may be ensured and where instead dynamic pull-in may arise. We build the integrity charts, which are able to illustrate if and in which parameter range the theoretical predictions can be guaranteed in practice. They may be used to establish safety factors to effectively operate the device according to the desired outcome, depending on the expected disturbances. © 2013 Springer Science+Business Media Dordrecht.

  1. Nonlinear dynamics of an electrically actuated imperfect microbeam resonator: Experimental investigation and reduced-order modeling

    KAUST Repository

    Ruzziconi, Laura

    2013-06-10

    We present a study of the dynamic behavior of a microelectromechanical systems (MEMS) device consisting of an imperfect clamped-clamped microbeam subjected to electrostatic and electrodynamic actuation. Our objective is to develop a theoretical analysis, which is able to describe and predict all the main relevant aspects of the experimental response. Extensive experimental investigation is conducted, where the main imperfections coming from microfabrication are detected, the first four experimental natural frequencies are identified and the nonlinear dynamics are explored at increasing values of electrodynamic excitation, in a neighborhood of the first symmetric resonance. Several backward and forward frequency sweeps are acquired. The nonlinear behavior is highlighted, which includes ranges of multistability, where the nonresonant and the resonant branch coexist, and intervals where superharmonic resonances are clearly visible. Numerical simulations are performed. Initially, two single mode reduced-order models are considered. One is generated via the Galerkin technique, and the other one via the combined use of the Ritz method and the Padé approximation. Both of them are able to provide a satisfactory agreement with the experimental data. This occurs not only at low values of electrodynamic excitation, but also at higher ones. Their computational efficiency is discussed in detail, since this is an essential aspect for systematic local and global simulations. Finally, the theoretical analysis is further improved and a two-degree-of-freedom reduced-order model is developed, which is also capable of capturing the measured second symmetric superharmonic resonance. Despite the apparent simplicity, it is shown that all the proposed reduced-order models are able to describe the experimental complex nonlinear dynamics of the device accurately and properly, which validates the proposed theoretical approach. © 2013 IOP Publishing Ltd.

  2. Monitoring the Dynamics of Water Flow at a High-Mountain Permafrost Site Using Electrical Self-Potential Measurements

    Science.gov (United States)

    Kemna, A.; Weigand, M.; Wagner, F.; Hilbich, C.; Hauck, C.

    2016-12-01

    Flow of (liquid) water plays a crucial role in the dynamics of coupled thermo-hydro-mechanical processes in terrestrial permafrost systems. To better understand these processes in the active layer of permafrost regions, with the ultimate goal of adequately incorporating them in numerical models for improved scenario prediction, monitoring approaches offering high spatial and temporal resolution, areal coverage, and especially sensitivity to subsurface water flow, are highly desired. This particularly holds for high-mountain slopes, where strong variability in topography, precipitation, and snow cover, along with significant subsurface soil/rock heterogeneity, gives rise to complex spatio-temporal patterns of water flow during seasonal thawing and freezing periods. The electrical self-potential (SP) method is well known to, in theory, meeting the above monitoring demands by measuring the electrical streaming potential which is generated at the microscopic scale when water flows along electrically non-neutral interfaces. Despite its inherent sensitivity to subsurface water flow, the SP method has not yet been used for the monitoring of high-mountain permafrost sites. We here present first results from an SP monitoring survey conducted at the Schilthorn (2970 m asl) in the Bernese Alps, Switzerland, where SP data have been collected since September 2013 at a sampling rate of 10 min on a permanently installed array of 12 non-polarizing electrodes covering an area of 35 m by 15 m. While the SP time series exhibit systematic daily variations, with part of the signal clearly correlated with temperature, in particular in the snow-free periods, the largest temporal changes in the SP signal occur in spring, when the snow cover melts and thawing sets on in the active layer. The period of higher temporal SP variations continues until autumn, when the signal gradually returns to relatively low variations, coinciding with the freezing of the ground. Our results suggest that the

  3. A Dynamic Control Strategy for Hybrid Electric Vehicles Based on Parameter Optimization for Multiple Driving Cycles and Driving Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Zhenzhen Lei

    2017-01-01

    Full Text Available The driving pattern has an important influence on the parameter optimization of the energy management strategy (EMS for hybrid electric vehicles (HEVs. A new algorithm using simulated annealing particle swarm optimization (SA-PSO is proposed for parameter optimization of both the power system and control strategy of HEVs based on multiple driving cycles in order to realize the minimum fuel consumption without impairing the dynamic performance. Furthermore, taking the unknown of the actual driving cycle into consideration, an optimization method of the dynamic EMS based on driving pattern recognition is proposed in this paper. The simulation verifications for the optimized EMS based on multiple driving cycles and driving pattern recognition are carried out using Matlab/Simulink platform. The results show that compared with the original EMS, the former strategy reduces the fuel consumption by 4.36% and the latter one reduces the fuel consumption by 11.68%. A road test on the prototype vehicle is conducted and the effectiveness of the proposed EMS is validated by the test data.

  4. Optimal economy-based battery degradation management dynamics for fuel-cell plug-in hybrid electric vehicles

    Science.gov (United States)

    Martel, François; Kelouwani, Sousso; Dubé, Yves; Agbossou, Kodjo

    2015-01-01

    This work analyses the economical dynamics of an optimized battery degradation management strategy intended for plug-in hybrid electric vehicles (PHEVs) with consideration given to low-cost technologies, such as lead-acid batteries. The optimal management algorithm described herein is based on discrete dynamic programming theory (DDP) and was designed for the purpose of PHEV battery degradation management; its operation relies on simulation models using data obtained experimentally on a physical PHEV platform. These tools are first used to define an optimal management strategy according to the economical weights of PHEV battery degradation and the secondary energy carriers spent to manage its deleterious effects. We then conduct a sensitivity study of the proposed optimization process to the fluctuating economic parameters associated with the fuel and energy costs involved in the degradation management process. Results demonstrate the influence of each parameter on the process's response, including daily total operating costs and expected battery lifetime, as well as establish boundaries for useful application of the method; in addition, they provide a case for the relevance of inexpensive battery technologies, such as lead-acid batteries, for economy-centric PHEV applications where battery degradation is a major concern.

  5. Excitation Method of Linear-Motor-Type Rail Brake without Using Power Sources by Dynamic Braking with Zero Electrical Output

    Science.gov (United States)

    Sakamoto, Yasuaki; Kashiwagi, Takayuki; Hasegawa, Hitoshi; Sasakawa, Takashi; Fujii, Nobuo

    The eddy current rail brake is a type of braking system used in railway vehicles. Because of problems such as rail heating and problems associated with ensuring that power is supplied when the feeder malfunctions, this braking system has not been used for practical applications in Japan. Therefore, we proposed the use of linear induction motor (LIM) technology in eddy current rail brake systems. The LIM rail brake driven by dynamic braking can reduce rail heating and generate the energy required for self-excitation. In this paper, we present an excitation system and control method for the LIM rail brake driven by “dynamic braking with zero electrical output”. The proposed system is based on the concept that the LIM rail brake can be energized without using excitation power sources such as a feeder circuit and that high reliability can be realized by providing an independent excitation system. We have studied this system and conducted verification tests using a prototype LIM rail brake on a roller rig. The results show that the system performance is adequate for commercializing the proposed system, in which the LIM rail brake is driven without using any excitation power source.

  6. Electrically evoked and voluntary maximal isometric tension in relation to dynamic muscle performance in elderly male subjects, aged 69 years.

    Science.gov (United States)

    Davies, C T; White, M J; Young, K

    1983-01-01

    The dynamic performance and electrically evoked mechanical properties of elderly triceps surae muscle have been investigated in 9 men, aged 69 yr. Dynamic performance consisted of cycling on a force bicycle and a vertical jump off two feet from a force platform. The results showed that the time to peak tension (TPT) and half relaxation time (1/2 RT) were significantly greater (p less than 0.001) by 30 ms and 22 ms and the supramaximal twitch (Pt) and tetanic (20 Hz-P020) tensions and maximal voluntary contraction (MVC) were less by 45 N (-33%), 708 N (-49%), and 899 N (-43%) in the elderly compared with young male control subjects. On the force platform, the height jumped (Ht), maximal force exerted (P), take-off velocity (VT), net impulse (NI) and peak power output (W) were less by 18.6 cm, 173 N, 0.9 ms-1, 52 Ns and 1120 w respectively. Similar differences of power, force and velocity were observed on the force bicycle. The reduction of W in the elderly was associated with the contractile characteristics of the leg muscle. The loss of contractile speed and capacity to to generate force in old people was reflected in their inability to develop power during the performance of a maximal vertical jump and cycling.

  7. Friction in carborane-based molecular rotors driven by gas flow or electric field: classical molecular dynamics.

    Science.gov (United States)

    Prokop, Alexandr; Vacek, Jaroslav; Michl, Josef

    2012-03-27

    Friction in molecular rotors is examined by classical molecular dynamics simulations for grid-mounted azimuthal dipolar molecular rotors, whose rotation is either allowed to decay freely or is driven at GHz frequencies by a flow of rare gas or by a rotating electric field. The rotating parts (rotators) are propeller-shaped. Their two to six blades consist of condensed aromatic rings and are attached to a deltahedral carborane hub, whose antipodal carbons carry [n]staffane axles mounted on a square molecular grid. The dynamic friction constant η has been derived in several independent ways with similar results. Analysis of free rotation decay yields η as a continuous exponentially decreasing function of rotor frequency. The calculated dependence of friction torque on frequency resembles the classical macroscopic Stribeck curve. Its relation to rotational potential energy barriers and the key role of the rate of intramolecular vibrational redistribution (IVR) of energy and angular momentum from rotator rotation to other modes are considered in two limiting regimes. (i) In the strongly overdamped regime, rotation is much slower than IVR, and effective friction can be expressed through potential barriers to rotation. (ii) In the strongly underdamped regime, rotation is much faster than IVR, whose rate then determines friction. © 2012 American Chemical Society

  8. Transient dynamics of a one-dimensional Holstein polaron under the influence of an external electric field

    Science.gov (United States)

    Huang, Zhongkai; Chen, Lipeng; Zhou, Nengji; Zhao, Yang

    2017-05-01

    Following the Dirac-Frenkel time-dependent variational principle, transient dynamics of a one-dimensional Holstein polaron with diagonal and off-diagonal exciton-phonon coupling in an external electric field is studied by employing the multi-D$_2$ {\\it Ansatz}, also known as a superposition of the usual Davydov D$_2$ trial states. Resultant polaron dynamics has significantly enhanced accuracy, and is in perfect agreement with that derived from the hierarchy equations of motion method. Starting from an initial broad wave packet, the exciton undergoes typical Bloch oscillations. Adding weak exciton-phonon coupling leads to a broadened exciton wave packet and a reduced current amplitude. Using a narrow wave packet as the initial state, the bare exciton oscillates in a symmetric breathing mode, but the symmetry is easily broken by weak coupling to phonons, resulting in a non-zero exciton current. For both scenarios, temporal periodicity is unchanged by exciton-phonon coupling. In particular, at variance with the case of an infinite linear chain, no steady state is found in a finite-sized ring within the anti-adiabatic regime. For strong diagonal coupling, the multi-$\\rm D_2$ {\\it Anstaz} is found to be highly accurate, and the phonon confinement gives rise to exciton localization and decay of the Bloch oscillations.

  9. An investigation of the static and dynamic behavior of electrically actuated rectangular microplates

    KAUST Repository

    Saghir, S.

    2016-06-16

    We present an investigation of the static and dynamic behavior of the nonlinear von-Karman plates when actuated by the nonlinear electrostatic forces. The investigation is based on a reduced order model developed using the Galerkin method, which rely on modeshapes and in-plane shape functions extracted using a finite element method. In this study, a fully clamped microplate is considered. We investigate the static behavior and the effect of different non-dimensional design parameters. The static results are validated by comparison with the results calculated by a finite element model. The forced-vibration response of the plate is then investigated when the plate is excited by a harmonic AC load superimposed to a DC load. The dynamic behavior is examined near the primary and secondary (superharmonic and subharmonic) resonances. The microplate shows a strong hardening behavior due to the cubic nonlinearity of mid-plane stretching. However, the behavior switches to softening as the DC load is increased. Finally, near-square plates are studied to understand the effect of geometric imperfections of microplates.

  10. Electrical resistivity dynamics beneath a fractured sedimentary bedrock riverbed in response to temperature and groundwater–surface water exchange

    Directory of Open Access Journals (Sweden)

    C. M. Steelman

    2017-06-01

    Full Text Available Bedrock rivers occur where surface water flows along an exposed rock surface. Fractured sedimentary bedrock can exhibit variable groundwater residence times, anisotropic flow paths, and heterogeneity, along with diffusive exchange between fractures and rock matrix. These properties of the rock will affect thermal transients in the riverbed and groundwater–surface water exchange. In this study, surface electrical methods were used as a non-invasive technique to assess the scale and temporal variability of riverbed temperature and groundwater–surface water interaction beneath a sedimentary bedrock riverbed. Conditions were monitored at a semi-daily to semi-weekly interval over a full annual period that included a seasonal freeze–thaw cycle. Surface electromagnetic induction (EMI and electrical resistivity tomography (ERT methods captured conditions beneath the riverbed along a pool–riffle sequence of the Eramosa River in Canada. Geophysical datasets were accompanied by continuous measurements of aqueous specific conductance, temperature, and river stage. Time-lapse vertical temperature trolling within a lined borehole adjacent to the river revealed active groundwater flow zones along fracture networks within the upper 10 m of rock. EMI measurements collected during cooler high-flow and warmer low-flow periods identified a spatiotemporal riverbed response that was largely dependent upon riverbed morphology and seasonal groundwater temperature. Time-lapse ERT profiles across the pool and riffle sequence identified seasonal transients within the upper 2 and 3 m of rock, respectively, with spatial variations controlled by riverbed morphology (pool versus riffle and dominant surficial rock properties (competent versus weathered rock rubble surface. While the pool and riffle both exhibited a dynamic resistivity through seasonal cooling and warming cycles, conditions beneath the pool were more variable, largely due to the formation of river

  11. Cardiovascular response of individuals with spinal cord injury to dynamic functional electrical stimulation under orthostatic stress.

    Science.gov (United States)

    Yoshida, Takashi; Masani, Kei; Sayenko, Dimitry G; Miyatani, Masae; Fisher, Joseph A; Popovic, Milos R

    2013-01-01

    In this pilot study, we examined how effectively functional electrical stimulation (FES) and passive stepping mitigated orthostatic hypotension in participants with chronic spinal cord injury (SCI). While being tilted head-up to 70 (°) from the supine position, the participants underwent four 10-min conditions in a random sequence: 1) no intervention, 2) passive stepping, 3) isometric FES of leg muscles, and 4) FES of leg muscles combined with passive stepping. We found that FES and passive stepping independently mitigated a decrease in stroke volume and helped to maintain the mean blood pressure. The effects of FES on stroke volume and mean blood pressure were greater than those of passive stepping. When combined, FES and passive stepping did not interfere with each other, but they also did not synergistically increase stroke volume or mean blood pressure. Thus, the present study suggests that FES delivered to lower limbs can be used in individuals with SCI to help them withstand orthostatic stress. Additional studies are needed to confirm whether this use of FES is applicable to a larger population of individuals with SCI.

  12. Design and Development of the Solar Dynamics Observatory (SDO) Electrical Power System

    Science.gov (United States)

    Denney, Keys; Burns, Michael; Kercheval, Bradford

    2009-01-01

    The SDO spacecraft was designed to help us understand the Sun's influence on Earth and Near-Earth space by studying the solar atmosphere on small scales of space and time and in many wavelengths simultaneously. It will perform its operations in a geosynchronous orbit of the earth. This paper will present background on the SDO mission, an overview of the design and development activities associated specifically with the SDO electrical power system (EPS), as well as the major driving requirements behind the mission design. The primary coverage of the paper will be devoted to some of the challenges faced during the design and development phase. This will include the challenges associated with development of a compatible CompactPCI (cPCI) interface within the Power System Electronics (PSE) in order to utilize a "common" processor card, implementation of new solid state power controllers (SSPC) for primary load distribution switching and over current protection in the PSE, and the design approach adopted to meet single fault tolerance requirements for all of the SDO EPS functions.

  13. Water content dynamics at plot scale - comparison of time-lapse electrical resistivity tomography monitoring and pore pressure modelling

    Science.gov (United States)

    Zieher, Thomas; Markart, Gerhard; Ottowitz, David; Römer, Alexander; Rutzinger, Martin; Meißl, Gertraud; Geitner, Clemens

    2017-01-01

    Physically-based dynamic modelling of shallow landslide susceptibility rests on several assumptions and simplifications. However, the applicability of physically-based models is only rarely tested in the field at the appropriate scale. This paper presents results of a spray irrigation experiment conducted on a plot of 100 m2 on an Alpine slope susceptible to shallow landsliding. Infiltrating precipitation applied at a constant rate (27.5 mm/h for 5.3 h) was monitored by means of 2D time-lapse electrical resistivity tomography, combined with time-domain reflectometry sensors installed at various depths. In addition, regolith characteristics were assessed by dynamic cone penetration tests using a light-weight cone penetrometer. The spray irrigation experiment resulted in a vertically progressing wetting front to a depth of 80-100 cm. Below that, the unconsolidated material was already saturated by rainfall in the previous days. The observed mean resistivity reduction attributed to infiltrating water during irrigation was scaled to pressure head. Mean variations in pore pressure were reproduced by a linear diffusion model also used in physically-based dynamic landslide susceptibility modelling. Sensitive parameters (hydraulic conductivity and specific storage) were tested over selected value ranges and calibrated. Calibrated parameter values are within published and experimentally derived ranges. The results of the comparison of observations and model results suggest that the model is capable of reproducing mean changes of pore pressure at a suitable scale for physically-based modelling of shallow landslide susceptibility. However, small-scale variations in pore pressure that may facilitate the triggering of shallow landslides are not captured by the model.

  14. What are people afraid of during dental treatment? Anxiety-provoking capacity of 67 stimuli characteristic of the dental setting

    NARCIS (Netherlands)

    Oosterink, F.M.D.; de Jongh, A.; Aartman, I.H.A.

    2008-01-01

    Relatively little is known about the anxiety-provoking capacity of the various objects and situations characteristic of the dental setting. The aims of the current study were to establish a hierarchy of anxiety-provoking capacities of a large set of dental stimuli and to determine the differences in

  15. Multi-Mode Electric Actuator Dynamic Modelling for Missile Fin Control

    Directory of Open Access Journals (Sweden)

    Bhimashankar Gurav

    2017-06-01

    Full Text Available Linear first/second order fin direct current (DC actuator model approximations for missile applications are currently limited to angular position and angular velocity state variables. Furthermore, existing literature with detailed DC motor models is decoupled from the application of interest: tail controller missile lateral acceleration (LATAX performance. This paper aims to integrate a generic DC fin actuator model with dual-mode feedforward and feedback control for tail-controlled missiles in conjunction with the autopilot system design. Moreover, the characteristics of the actuator torque information in relation to the aerodynamic fin loading for given missile trim velocities are also provided. The novelty of this paper is the integration of the missile LATAX autopilot states and actuator states including the motor torque, position and angular velocity. The advantage of such an approach is the parametric analysis and suitability of the fin actuator in relation to the missile lateral acceleration dynamic behaviour.

  16. Dynamic electrical impedance imaging of a chest phantom using the Kalman filter.

    Science.gov (United States)

    Kim, Bong Seok; Kim, Kyung Youn; Kao, Tzu-Jen; Newell, Jonathan C; Isaacson, David; Saulnier, Gary J

    2006-05-01

    A dynamic complex impedance imaging technique is developed with the aid of the linearized Kalman filter (LKF) for real-time reconstruction of the human chest. The forward problem is solved by an analytical method based on the separation of variables and Fourier series. The inverse problem is treated as a state estimation problem. The nonlinear measurement equation is linearized about the best homogeneous impedivity value as an initial guess, and the impedivity distribution is estimated with the aid of the Kalman estimator. The Kalman gain matrix is pre-computed and stored off-line to minimize the on-line computational time. Simulation and phantom experiment are reported to illustrate the reconstruction performances in the sense of spatio-temporal resolution in a simplified geometry of the human chest.

  17. Vibrational contributions to the dynamic electric properties of the NaF molecule

    Science.gov (United States)

    Pessoa, Renato; Castro, Marcos A.; Amaral, Orlando A. V.; Fonseca, Tertius L.

    2004-11-01

    In this work, we report calculations of the vibrational corrections to the dynamic polarizability and first hyperpolarizability of the NaF molecule performed through the CPHF method. We have considered frequencies varying from 0 to 0.12 hartree. Results obtained show that the zpva contributions are small in comparison with the corresponding electronic contributions. It is shown that both contributions can be well described by quartic polynomial fits. The pv contributions are important on the vibrational range of frequencies but negligible on the visible region, except for βxxz(-ω; ω,0) and βzzz(-ω; ω, 0). A detailed study of the pv contributions over the range of vibrational frequencies, including an electron correlation treatment at the CCSD(T) level, is presented.

  18. Vibrational contributions to the dynamic electric properties of the NaF molecule

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, Renato [Instituto de Fisica, Universidade Federal de Goias (UFG), Campus Samambaia, Caixa Postal 131, 74001-970 Goiania, Goias (Brazil); Castro, Marcos A. [Instituto de Fisica, Universidade Federal de Goias (UFG), Campus Samambaia, Caixa Postal 131, 74001-970 Goiania, Goias (Brazil)]. E-mail: mcastro@if.ufg.br; Amaral, Orlando A.V. [Instituto de Fisica, Universidade Federal de Goias (UFG), Campus Samambaia, Caixa Postal 131, 74001-970 Goiania, Goias (Brazil); Fonseca, Tertius L. [Instituto de Fisica, Universidade Federal de Goias (UFG), Campus Samambaia, Caixa Postal 131, 74001-970 Goiania, Goias (Brazil)

    2004-11-15

    In this work, we report calculations of the vibrational corrections to the dynamic polarizability and first hyperpolarizability of the NaF molecule performed through the CPHF method. We have considered frequencies varying from 0 to 0.12 hartree. Results obtained show that the zpva contributions are small in comparison with the corresponding electronic contributions. It is shown that both contributions can be well described by quartic polynomial fits. The pv contributions are important on the vibrational range of frequencies but negligible on the visible region, except for {beta}{sub xxz}(-{omega}; {omega},0) and {beta}{sub zzz}(-{omega}; {omega}, 0). A detailed study of the pv contributions over the range of vibrational frequencies, including an electron correlation treatment at the CCSD(T) level, is presented.

  19. Initial dynamics of the EKG during an electrical defibrillation of the heart

    Science.gov (United States)

    Bikov, I. I.; Chebotarov, Y. P.; Nikolaev, V. G.

    1980-01-01

    In tests on 11 mature dogs, immobilized by means of an automatic blocking and synchronization system, artefact free EKG were obtained, beginning 0.04-0.06 sec after passage of a defibrillating current. Different versions of the start of fibrillation were noted, in application of the defibrillating stimulus in the early phase of the cardiac cycle. A swinging phenomenon, increasing amplitude, of fibrillation was noted for 0.4-1.5 sec after delivery of a subthreshold stimulus. Conditions for a positive outcome of repeated defibrillation were found, and a relationship was noted between the configuration of the exciting process with respect to the lines of force of the defibrillating current and the defibrillation threshold. It was shown that the initial EKG dynamics after defibrillation is based on a gradual shift of the pacemaker from the myocardium of the ventricles to the sinus node, through phases of atrioventricular and atrial automatism.

  20. An ultrafast programmable electrical tester for enabling time-resolved, sub-nanosecond switching dynamics and programming of nanoscale memory devices

    Science.gov (United States)

    Shukla, Krishna Dayal; Saxena, Nishant; Manivannan, Anbarasu

    2017-12-01

    Recent advancements in commercialization of high-speed non-volatile electronic memories including phase change memory (PCM) have shown potential not only for advanced data storage but also for novel computing concepts. However, an in-depth understanding on ultrafast electrical switching dynamics is a key challenge for defining the ultimate speed of nanoscale memory devices that demands for an unconventional electrical setup, specifically capable of handling extremely fast electrical pulses. In the present work, an ultrafast programmable electrical tester (PET) setup has been developed exceptionally for unravelling time-resolved electrical switching dynamics and programming characteristics of nanoscale memory devices at the picosecond (ps) time scale. This setup consists of novel high-frequency contact-boards carefully designed to capture extremely fast switching transient characteristics within 200 ± 25 ps using time-resolved current-voltage measurements. All the instruments in the system are synchronized using LabVIEW, which helps to achieve various programming characteristics such as voltage-dependent transient parameters, read/write operations, and endurance test of memory devices systematically using short voltage pulses having pulse parameters varied from 1 ns rise/fall time and 1.5 ns pulse width (full width half maximum). Furthermore, the setup has successfully demonstrated strikingly one order faster switching characteristics of Ag5In5Sb60Te30 (AIST) PCM devices within 250 ps. Hence, this novel electrical setup would be immensely helpful for realizing the ultimate speed limits of various high-speed memory technologies for future computing.

  1. Dynamics of ultra-short electromagnetic pulses in the system of chiral carbon nanotube waveguides in the presence of external alternating electric field

    Energy Technology Data Exchange (ETDEWEB)

    Konobeeva, N.N., E-mail: yana_nn@inbox.ru [Volgograd State University, University Avenue 100, Volgograd 400062 (Russian Federation); Belonenko, M.B. [Volgograd Institute of Business, Uzhno-ukrainskaya str., Volgograd 400048 (Russian Federation)

    2014-04-01

    The paper addresses the propagation of ultra-short optical pulses in chiral carbon nanotubes in the presence of external alternating electric field. Following the assumption that the considered optical pulses are represented in the form of discrete solitons, we analyze the wave equation for the electromagnetic field and consider the dynamics of pulses in external field, their initial amplitudes and frequencies.

  2. Establishing conditions for simulating hydrophobic solutes in electric fields by molecular dynamics Effects of the long-range van der Waals treatment on the apparent particle mobility

    NARCIS (Netherlands)

    Milicevic, Zoran; Marrink, Siewert J.; Smith, Ana-Suncana; Smith, David M.

    Despite considerable effort over the last decade, the interactions between solutes and solvents in the presence of electric fields have not yet been fully understood. A very useful manner in which to study these systems is through the application of molecular dynamics (MD) simulations. However, a

  3. Dynamic Game Analysis of Coal Electricity Market Involving Multi-Interests

    Directory of Open Access Journals (Sweden)

    Yu Xiaobao

    2016-01-01

    Full Text Available The coal consumption of China reached 2.75 billion tons of standard coal in 2013, which accounted for 67.5% of total energy consumption and more than 50% of global coal consumption. Therefore, the impact of coal price is huge on coal market and even energy market in China. As a large consumer of coal, thermal power enterprise has a strong sensitivity to coal price. In order to balance the rising cost of enterprises due to coal price, we need to analyze the interests of multiple stakeholders. Firstly, this paper combined the Nash equilibrium and cobweb model and proposed the characteristics in different cobweb model. Then, for coal, power, and energy companies, the dynamic game analysis model is constructed. This model gives a game analysis in four scenarios and quantifies the decision of each stakeholder in different coal prices. Finally, the impact figure of different coal prices on each stakeholder has been drawn. The impacts of different coal or thermal power prices on different markets have been put forward, so relevant policy recommendations have been proposed combined with the cobweb model.

  4. In Situ Monitoring of Dispersion Dynamics of Carbon Nanotubes during Sonication Using Electrical Conductivity Measurements

    Directory of Open Access Journals (Sweden)

    Syed Sadiq Ali

    2015-01-01

    Full Text Available The main challenge in the fabrication of carbon nanotube- (CNT- based composite materials is the optimization of the sonication time in order to obtain homogenous and uniform dispersion of CNTs. Past studies mostly relied on postprocessing characterization techniques to address this issue. In the present, however, in situ monitoring of dispersion dynamics of CNTs in distilled water is carried out using instantaneous conductivity measurements. Using a computer controlled data acquisition system, the time evolution of the solution conductivity was carefully recorded. The data were then used to evaluate the intensity of turbulent fluctuations, which clearly highlighted the existence of three distinct sonication phases. During the first phase, the conductivity fluctuations initially increased attaining ultimately a maximum, thus indicating the occurrence of large agglomerates of CNTs. During the second phase of sonication, the solution conductivity showed a rather steep increase while fluctuations steadily declined. This phenomenon can be attributed to the breakdown of large CNT agglomerates, resulting in greater dispersion homogeneity of CNTs. During the third phase, after almost 650 kJ/L of sonication energy, the conductivity increase was almost negligible. The fluctuation intensity also remained constant during this phase signifying that the further sonication was no longer required.

  5. Multimode Analysis of the Dynamics and Integrity of Electrically Actuated MEMS Resonators

    Directory of Open Access Journals (Sweden)

    Serge Bruno Yamgoué

    2014-01-01

    technique to reduce the partial integro-differential equation governing the dynamics of the microbeam to a system of coupled ordinary differential equations which describe the interactions of the linear mode shapes of the microbeam. Analytical solutions are derived and their stability is studied for the simplest reduced-order model which takes into account only the first linear mode in the Galerkin procedure. We further investigate the influence of the first few higher modes on the Galerkin procedure, and hence its convergence, by analysing the boundaries between pull-in and pull-in-free vibrations domains in the space of actuation parameters. These are determined for the various multimode combinations using direct numerical time integration. Our results show that unsafe domains form V-like shapes for actuation frequencies close to the superharmonic, fundamental, and subharmonic resonances. They also reveal that the single first-mode reduced model usually considered underestimates the left branches and overestimates the right branches of these boundaries.

  6. Inhibition of Bcl-2 or IAP proteins does not provoke mutations in surviving cells

    Energy Technology Data Exchange (ETDEWEB)

    Shekhar, Tanmay M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Green, Maja M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Department of Anatomy & Neuroscience, The University of Melbourne, Parkville 3010 (Australia); Rayner, David M.; Miles, Mark A.; Cutts, Suzanne M. [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia); Hawkins, Christine J., E-mail: c.hawkins@latrobe.edu.au [Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora 3083 (Australia)

    2015-07-15

    Graphical abstract: - Highlights: • Mutagenicities of anti-cancer drugs were tested using HPRT, γH2AX and comet assays. • TRAIL, doxorubicin and etoposide were more mutagenic than BH3- or Smac-mimetics. • Physiologically achievable levels of the BH3-mimetic ABT-737 were not mutagenic. • High concentrations of ABT-737 provoked mutations via an off-target mechanism. • Even very high concentrations of IAP antagonists were not mutagenic. - Abstract: Chemotherapy and radiotherapy can cause permanent damage to the genomes of surviving cells, provoking severe side effects such as second malignancies in some cancer survivors. Drugs that mimic the activity of death ligands, or antagonise pro-survival proteins of the Bcl-2 or IAP families have yielded encouraging results in animal experiments and early phase clinical trials. Because these agents directly engage apoptosis pathways, rather than damaging DNA to indirectly provoke tumour cell death, we reasoned that they may offer another important advantage over conventional therapies: minimisation or elimination of side effects such as second cancers that result from mutation of surviving normal cells. Disappointingly, however, we previously found that concentrations of death receptor agonists like TRAIL that would be present in vivo in clinical settings provoked DNA damage in surviving cells. In this study, we used cell line model systems to investigate the mutagenic capacity of drugs from two other classes of direct apoptosis-inducing agents: the BH3-mimetic ABT-737 and the IAP antagonists LCL161 and AT-406. Encouragingly, our data suggest that IAP antagonists possess negligible genotoxic activity. Doses of ABT-737 that were required to damage DNA stimulated Bax/Bak-independent signalling and exceeded concentrations detected in the plasma of animals treated with this drug. These findings provide hope that cancer patients treated by BH3-mimetics or IAP antagonists may avoid mutation-related illnesses that afflict

  7. Recruitment methods in a clinical trial of provoked vulvodynia: Predictors of enrollment.

    Science.gov (United States)

    Bachour, Candi C; Bachmann, Gloria A; Foster, David C; Wan, Jim Y; Rawlinson, Leslie A; Brown, Candace S

    2017-02-01

    Successful recruitment in clinical trials for chronic pain conditions is challenging, especially in women with provoked vulvodynia due to reluctance in discussing pain associated with sexual intercourse. The most successful recruitment methods and the characteristics of women reached with these methods are unknown. To compare the effectiveness and efficiency of four recruitment methods and to determine socioeconomic predictors for successful enrollment in a National Institutes of Health-sponsored multicenter clinical trial evaluating a gabapentin intervention in women with provoked vulvodynia. Recruitment methods utilized mass mailing, media, clinician referrals and community outreach. Effectiveness (number of participants enrolled) and efficiency (proportion screened who enrolled) were determined. Socioeconomic variables including race, educational level, annual household income, relationship status, age, menopausal status and employment status were also evaluated regarding which recruitment strategies were best at targeting specific cohorts. Of 868 potential study participants, 219 were enrolled. The most effective recruitment method in enrolling participants was mass mailing ( p recruitment methods ( p = 0.11). Relative to clinician referral, black women were 13 times as likely to be enrolled through mass mailing (adjusted odds ratio 12.5, 95% confidence interval, 3.6-43.1) as white women. There were no differences in enrollment according to educational level, annual income, relationship status, age, menopausal status, or employment status and recruitment method. In this clinical trial, mass mailing was the most effective recruitment method. Race of participants enrolled in a provoked vulvodynia trial was related to the recruitment method.

  8. Entitled vengeance: A meta-analysis relating narcissism to provoked aggression.

    Science.gov (United States)

    Rasmussen, Kyler

    2016-07-01

    Narcissism has long been used to predict aggressive or vengeful responses to provocations from others. The strength of this relation can, however, vary widely from study to study. Narcissism and revenge were examined in 84 independent samples (N = 11297), along with the moderating role of sample type (i.e., child/adolescent, prisoner, undergraduate, or general samples), type of narcissism measure used (i.e., Narcissistic Personality Inventory, Psychological Entitlement Scale, Short D3, etc.), the nature of the provocation, and the type of provoked aggression examined. Narcissism was positively related to provoked aggression across studies (ρ = .25), but that relation was stronger in child/adolescent samples (ρ = .36) and when measures of entitlement or vulnerable narcissism were employed (ρ = .29). Implications for practical research, as well as neglected areas of research on narcissism and provoked aggression are discussed. Aggr. Behav. 42:362-379, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  9. A case report of successful team approach treatment of provoked vulvodynia

    Directory of Open Access Journals (Sweden)

    Gabrijela Simetinger

    2015-10-01

    Full Text Available AbstractBackground: Vulvodynia has been defined as vulvar discomfort, most often described as burning pain, occurring in the absence of relevant findings or a specific, clinically identifiable, neurologic disorder. Vulvodynia is a genital syndrome of multi-causal origin and requires a team approach. The purpose of the case report of provoked vulvodynia is to show the efficacy of individualized, multifaceted and multidisciplinary therapeutic team approach used by a gynaecologist with special knowledge of sexology and a physiotherapist specialising in treatment of pelvic floor dysfunction. Case report: A 35-year old patient presented with a complaint of genital itching and consequently burning pain which first occurred during sexual intercourse one year previously. Afterwards a gynaecologist with special knowledge of sexology performed a biopsychosocial assessment, broader gynaecological examination and psychoeducation. Diagnosed was provoked vulvodynia. Than she was assessed by the physiotherapist specialising in treatment of pelvic floor dysfunction and treated with TENS. To assess the effectiveness of treatment were used Female Sexual Function Index questionnaire and the visual analogue scale before and after the team approach treatment. Conclusions: In our case individualized, multifaceted and multidisciplinary therapeutic approach proved to be a good choice for treating genital syndrome of provoked vulvodynia of multi-causal origin.

  10. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  11. Learning-Related Brain-Electrical Activity Dynamics Associated with the Subsequent Impact of Learnt Action-Outcome Associations

    Directory of Open Access Journals (Sweden)

    Fabian Baum

    2017-05-01

    Full Text Available Goal-directed behavior relies on the integration of anticipated outcomes into action planning based on acquired knowledge about the current contingencies between behavioral responses (R and desired outcomes (O under specific stimulus conditions (S. According to ideomotor theory, bidirectional R-O associations are an integral part of this knowledge structure. Previous EEG studies have identified neural activity markers linked to the involvement of such associations, but the initial acquisition process has not yet been characterized. The present study thus examined brain-electrical activity dynamics during the rapid acquisition of novel bidirectional R-O associations during instructed S-R learning. Within a trial, we inspected response-locked and stimulus-locked activity dynamics in order to identify markers linked to the forward and backward activation of bidirectional R-O associations as they were being increasingly strengthened under forced choice conditions. We found that a post-response anterior negativity following auditory outcomes was increasingly attenuated as a function of the acquired association strength. This suggests that previously reported action-induced sensory attenuation effects under extensively trained free choice conditions can be established within few repetitions of specific R-O pairings under forced choice conditions. Furthermore, we observed the even more rapid development of a post-response but pre-outcome fronto-central positivity which was reduced for high R-O learners which might indicate the rapid deployment of preparatory attention towards predictable outcomes. Finally, we identified a learning-related stimulus-locked activity modulation within the visual P1-N1 latency range which might reflect the multi-sensory integration of the perceived antecedent visual stimulus the anticipated auditory outcome.

  12. Variation of poorly ventilated lung units (silent spaces) measured by electrical impedance tomography to dynamically assess recruitment.

    Science.gov (United States)

    Spadaro, Savino; Mauri, Tommaso; Böhm, Stephan H; Scaramuzzo, Gaetano; Turrini, Cecilia; Waldmann, Andreas D; Ragazzi, Riccardo; Pesenti, Antonio; Volta, Carlo Alberto

    2018-01-31

    Assessing alveolar recruitment at different positive end-expiratory pressure (PEEP) levels is a major clinical and research interest because protective ventilation implies opening the lung without inducing overdistention. The pressure-volume (P-V) curve is a validated method of assessing recruitment but reflects global characteristics, and changes at the regional level may remain undetected. The aim of the present study was to compare, in intubated patients with acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS), lung recruitment measured by P-V curve analysis, with dynamic changes in poorly ventilated units of the dorsal lung (dependent silent spaces [DSSs]) assessed by electrical impedance tomography (EIT). We hypothesized that DSSs might represent a dynamic bedside measure of recruitment. We carried out a prospective interventional study of 14 patients with AHRF and ARDS admitted to the intensive care unit undergoing mechanical ventilation. Each patient underwent an incremental/decremental PEEP trial that included five consecutive phases: PEEP 5 and 10 cmH 2 O, recruitment maneuver + PEEP 15 cmH 2 O, then PEEP 10 and 5 cmH 2 O again. We measured, at the end of each phase, recruitment from previous PEEP using the P-V curve method, and changes in DSS were continuously monitored by EIT. PEEP changes induced alveolar recruitment as assessed by the P-V curve method and changes in the amount of DSS (p Recruited volume measured by the P-V curves significantly correlated with the change in DSS (r s  = 0.734, p recruitment measured using the P-V curve technique. EIT might provide useful information to titrate personalized PEEP. ClinicalTrials.gov, NCT02907840 . Registered on 20 September 2016.

  13. [Effects of transcutaneous electrical acupoint stimulation combined with general anesthesia on changes of gastric dynamics in controlled hypotension dogs].

    Science.gov (United States)

    Fang, Jian-Qiao; Zhang, Le-Le; Shao, Xiao-Mei; Lian, Lin-Li; Yu, Xiao-Jing; Dong, Zhen-Hua; Mo, Ya-Di

    2011-12-01

    To observe the effect of transcutaneous electrical acupoint stimulation (TEAS) combined with general anesthesia on gastric dynamics in controlled hypotension dogs, so as to provide experimental evidence for compound acupuncture anesthesia. Eighteen male beagle dogs were randomly divided into general anesthesia group (GA group, n = 6), general anesthesia + controlled hypotension group (GA + OHT group, n = 6) and general anesthesia combined with TEAS + controlled hypotension group (TEAS group, n = 6). The latter two groups were administered with the same anesthetics [isofluane inhalation and intravenous sodium nitroprusside (SNP)] for inducing controlled hypotension (being the 40% of the baseline level). Beagles of the GA group were not treated with controlled hypotension (the initial concentration of SNP = 1 microg/kg x min(-1), and with an increase rate of 1 microg/kg x min(-1) until the controlled hypotension phase). In the TEAS group, TEAS [2 Hz/100 Hz, (4 +/- 1) mA]was applied to "Quchi" (LI 11) , "Zusanli" (ST 36), "Hegu" (LI 4), and "Sanyinjiao" (SP 6) from the beginning of the stable physiological condition phase to the end of the controlled-low mean arterial pressure (MAP) phase. Electrogastrogram (EGG) was recorded, and serum gastrin (GAS) and motilin (MTL) contents were detected by enzyme-linked immunosorbent assay. Compared with the basic level, the amplitude value of EGG at 60 mm after controlled hypotension in the GA + CHT group was significantly lower (P 0.05), and serum GAS level at the time-point of 2 h after MAP recovery in the TEAS group was considerably higher than those in the GA and GA + CHT groups (P 0.05). TEAS combining with general anesthesia for controlled hypotension can improve the amplitude of EGG, and serum MTL and GAS contents, favoring the recovery of gastric dynamics and the functional protection of stomach.

  14. An Experimental Study of the Impact of Dynamic Electricity Pricing on Consumer Behavior: An Analysis for a Remote Island in Japan

    Directory of Open Access Journals (Sweden)

    Thoa Thi Kim Nguyen

    2016-12-01

    Full Text Available The aim of this research was to investigate how consumer behavior changes after application of dynamic electricity pricing and the persistence of those changes. Based on the investigation results, the authors also discuss the policy implications of demand management to shift consumption to days that have more solar radiation, while at the same time reducing overall consumption. The dynamic pricing experiment was implemented on Nushima Island, located in the center of Japan, with the participation of 50 households. The methodologies used in this study are panel analysis with random effects, and the difference in differences method. Several linear regression analyses are performed to predict hourly electricity usage from a number of explanatory variables, such as life-style factors, the frequency of access to the visualization website, control for weather factors (wind speed and temperatures, and other attributes of the households to predict the log of hourly electric energy consumption. The results show that dynamic pricing brought about 13.8% reduction of electric energy consumption in comparison with the pre-experiment period. Also, by applying a new experimental design approach, this study finds data supportive of habit formation by participants. Based on the findings, this research tries to develop a policy for sustainable energy conservation in remote islands.

  15. Modeling of the effects of the electrical dynamics on the electromechanical response of a DEAP circular actuator with a mass-spring load

    Science.gov (United States)

    Rizzello, G.; Hodgins, M.; Naso, D.; York, A.; Seelecke, S.

    2015-09-01

    This paper presents a modeling approach of an actuator system based on a dielectric electro-active polymer (DEAP) circular membrane mechanically loaded with a mass and a linear spring. The motion is generated by the deformation of the membrane caused by the electrostatic compressive force between two compliant electrodes applied on the surface of the polymer. A mass and a linear spring are used to pre-load the membrane, allowing stroke in the out-of-plane direction. The development of mathematical models which accurately describe the nonlinear coupling between electrical and mechanical dynamics is a fundamental step in order to design model-based, high-precision position control algorithms operating in high-frequency regimes (up to 150 Hz). The knowledge of the nonlinear electrical dynamics of the actuator driving circuit can be exploited during the control system design in order to achieve desirable features, such as higher modeling accuracy for high-frequency actuation, self-sensing or control energy minimization. This work proposes a physical model of the DEAP actuator system which couples both electrical and mechanical dynamics occurring during the actuation process. By means of numerous experiments, it is shown that the model can be used to predict both actuator current and displacement, and therefore to increase the overall displacement prediction accuracy with respect to actuator models which neglect electrical behavior.

  16. Integration Design and Optimization Control of a Dynamic Vibration Absorber for Electric Wheels with In-Wheel Motor

    Directory of Open Access Journals (Sweden)

    Mingchun Liu

    2017-12-01

    Full Text Available This paper presents an integration design scheme and an optimization control strategy for electric wheels to suppress the in-wheel vibration and improve vehicle ride comfort. The in-wheel motor is considered as a dynamic vibration absorber (DVA, which is isolated from the unsprung mass by using a spring and a damper. The proposed DVA system is applicable for both the inner-rotor motor and outer-rotor motor. Parameters of the DVA system are optimized for the typical conditions, by using the particle swarm optimization (PSO algorithm, to achieve an acceptable vibration performance. Further, the DVA actuator force is controlled by using the alterable-domain-based fuzzy control method, to adaptively suppress the wheel vibration and reduce the wallop acting on the in-wheel motor (IWM as well. In addition, a suspension actuator force is also controlled, by using the linear quadratic regulator (LQR method, to enhance the suspension performance and meanwhile improve vehicle ride comfort. Simulation results demonstrate that the proposed DVA system effectively suppresses the wheel vibration and simultaneously reduces the wallop acting on the IWM. Also, the alterable-domain-based fuzzy control method performs better than the conventional ones, and the LQR-based suspension exhibits excellent performance in vehicle ride comfort.

  17. An improved mechanism for capacity payment based on system dynamics modeling for investment planning in competitive electricity environment

    Energy Technology Data Exchange (ETDEWEB)

    Assili, Mohsen; Javidi DB, M. H.; Ghazi, Reza [Department of Electrical Engineering, Ferdowsi University of Mashhad, Mashhad (Iran)

    2008-10-15

    Many countries have experienced restructuring in their electric utilities. This restructuring has presented the power industries with new challenges, the most important of which is long-term investment planning under uncertain conditions. This paper presents an improved mechanism for capacity payment. The mechanism has been investigated based on system dynamic modeling. In our proposed mechanism, generators will recover a part of their investment through capacity payment. While the payment for any plant remains constant during the operation period, it depends on the investment needed to build it. The main factors affecting long-term planning have been considered in our model. The approach can be used to investigate the effects of fixed as well as variable capacity payment in market investment. We used the probability density function of load as a new concept to calculate average market price. Delays in unit constructions, estimation of demand, and market capacity growth during construction periods have been included in the proposed algorithm as parameters, which affect the regulator's decision for changing capacity payment. The model can be used by regulators to investigate strategies that may affect the fluctuations in the market. (author)

  18. MOLECULAR DOCKING AND DYNAMICS STUDIES ON THE PROTEIN-PROTEIN INTERACTIONS OF ELECTRICALLY ACTIVE PILIN NANOWIRES OF GEOBACTER SULFURREDUCENS.

    Directory of Open Access Journals (Sweden)

    D. Jeya Sundara Sharmila1 *

    2017-06-01

    Full Text Available Molecular interactions are key aspects in biological recognitions applicable in nano/micro systems. Bacterial nanowires are pilus filament based structures that can conduct electrons. The transport of electron is proposed to be facilitated by filamentous fibers made up of polymeric assemblies of proteins called pilin. Geobacter sulfurreducens is capable of delivering electrons through extracellular electron transport (EET by employing conductive nanowires, which are pilin proteins composed of type IV subunit PilA. Protein-protein interactions play an important role in the stabilization of the pilin nanowire assembly complex and it contains transmembrane (TM domain. In current study, protein-protein docking and multiple molecular dynamic (MD simulations were performed to understand the binding mode of pilin nanowires. The MD result explains the conformational behavior and folding of pilin nanowires in water environment in different time scale duration 20, 5, 5, 10 and 20ns (total of 60ns. Direct hydrogen bonds and water mediated hydrogen bonds that play a crucial role during the simulation were investigated. The conformational state, folding, end-toend distance profile and hydrogen bonding behavior had indicated that the Geobacter sulfurreducens pilin nanowires have electrical conductivity properties.

  19. Influence of typical faults over the dynamic behavior of pantograph-catenary contact force in electric rail transport

    Science.gov (United States)

    Rusu-Anghel, S.; Ene, A.

    2017-05-01

    The quality of electric energy capture and also the equipment operational safety depend essentially of the technical state of the contact line (CL). The present method for determining the technical state of CL based on advance programming is no longer efficient, due to the faults which can occur into the not programmed areas. Therefore, they cannot be remediated. It is expected another management method for the repairing and maintenance of CL based on its real state which must be very well known. In this paper a new method for determining the faults in CL is described. It is based on the analysis of the variation of pantograph-CL contact force in dynamical regime. Using mathematical modelling and also experimental tests, it was established that each type of fault is able to generate ‘signatures’ into the contact force diagram. The identification of these signatures can be accomplished by an informatics system which will provide the fault location, its type and also in the future, the probable evolution of the CL technical state. The measuring of the contact force is realized in optical manner using a railway inspection trolley which has appropriate equipment. The analysis of the desired parameters can be accomplished in real time by a data acquisition system, based on dedicated software.

  20. Experimental verification of a thermal equivalent circuit dynamic model on an extended range electric vehicle battery pack

    Science.gov (United States)

    Ramotar, Lokendra; Rohrauer, Greg L.; Filion, Ryan; MacDonald, Kathryn

    2017-03-01

    The development of a dynamic thermal battery model for hybrid and electric vehicles is realized. A thermal equivalent circuit model is created which aims to capture and understand the heat propagation from the cells through the entire pack and to the environment using a production vehicle battery pack for model validation. The inclusion of production hardware and the liquid battery thermal management system components into the model considers physical and geometric properties to calculate thermal resistances of components (conduction, convection and radiation) along with their associated heat capacity. Various heat sources/sinks comprise the remaining model elements. Analog equivalent circuit simulations using PSpice are compared to experimental results to validate internal temperature nodes and heat rates measured through various elements, which are then employed to refine the model further. Agreement with experimental results indicates the proposed method allows for a comprehensive real-time battery pack analysis at little computational expense when compared to other types of computer based simulations. Elevated road and ambient conditions in Mesa, Arizona are simulated on a parked vehicle with varying quiescent cooling rates to examine the effect on the diurnal battery temperature for longer term static exposure. A typical daily driving schedule is also simulated and examined.

  1. An Autonomous Coil Alignment System for the Dynamic Wireless Charging of Electric Vehicles to Minimize Lateral Misalignment

    Directory of Open Access Journals (Sweden)

    Karam Hwang

    2017-03-01

    Full Text Available This paper proposes an autonomous coil alignment system (ACAS for electric vehicles (EVs with dynamic wireless charging (DWC to mitigate the reduction in received power caused by lateral misalignment between the source and load coils. The key component of the ACAS is a novel sensor coil design, which can detect the load coil’s left or right position relative to the source coil by observing the change in voltage phase. This allows the lateral misalignment to be estimated through the wireless power transfer (WPT system alone, which is a novel tracking method for vehicular applications. Once misalignment is detected, the vehicle’s lateral position is self-adjusted by an autonomous steering function. The feasibility of the overall operation of the ACAS was verified through simulation and experiments. In addition, an analysis based on experimental results was conducted, demonstrating that 26% more energy can be transferred during DWC with the ACAS, just by keeping the vehicle’s load coil aligned with the source coil.

  2. Scale-up of an electrical capacitance tomography sensor for imaging pharmaceutical fluidized beds and validation by computational fluid dynamics

    Science.gov (United States)

    Wang, Haigang; Yang, Wuqiang

    2011-10-01

    The aim of this research is to apply electrical capacitance tomography (ECT) in pharmaceutical fluidized beds and scale up the application of ECT from a lab-scale fluidized bed to a production-scale fluidized bed. The objective is to optimize the design of the production-scale fluidized bed and to improve the operation efficiency of the fluidization processes. This is the first time that ECT has been scaled up to a production-scale fluidized bed of 1.0 m diameter and batch process capacity of 100 kg in a real industrial environment. With a large-scale fluidized bed in a real industrial environment, some key issues on the ECT sensor design must be addressed. To validate ECT measurement results, a two-phase flow model has been used to simulate the process in a lab-scale and pilot-scale fluidized bed. The key process parameters include solid concentration, average concentration profiles, the frequency spectrum of signal fluctuation obtained by the fast Fourier transfer (FFT) and multi-level wavelet decomposition in the time domain. The results show different hydrodynamic behaviour of fluidized beds of different scales. The time-averaged parameters from ECT and computational fluid dynamics are compared. Future work on the ECT sensor design for large-scale fluidized beds are given in the end of the paper.

  3. Influence of the electric polarization on carrier transport and recombinaton dynamics in ZnO-based heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Matthias

    2010-08-16

    The present thesis deals with the influence of the electric polarization on properties of free carriers in ZnO-based semiconductor heterostructures. Thereby especially transport properties of free carriers as well as their recombination dynamics are studied. The thesis treats four main topics. The first main topic lies on the phsical properties of the applied materials, here the connection of the band gap and the lattice constant of thin Mg{sub x}Zn{sub 1-x}O films and their magnesium content is described. Furthermore the morphology of such films is discussed. Different substrates and deposition conditions are thereby detailedly considered. The second main topic treats the properties of undoped and phosphorus doped thin ZnO and Mg{sub x}Zn{sub 1-x}O films. The structural, transport, and luminescence properties are here compared and conclusions drawn on the growth conditions. In the third main topic quantum effects on ZnO/Mg{sub x}Zn{sub 1-x}O interfaces are treated. Hereby especially the influence of the electric polarization is considered. The presence of a two-dimensional electron gas is proved, and the necessary conditions for the generation of the so-called confined Stark effect are explained. Especially the growth-relevant parameters are considered. The fourth main topic represent coupling phenomena in ZnO/BaTiO{sub 3} heterostructures. Thereby first the experimentally observed properties of different heterostructures are shown, which were grown on different substrates. Here structural and transport properties hold the spotlight. A model for the description of the formation of space-charge zones in such heterostructures is introduced and applied for the description of the experimental results. The usefulness of the ferroelectric properties of the material BaTiO{sub 3} in combination with semiconducting ZnO were studied. For this ferroelectric field effect transistors were fabricated under application of both materials. The principle suitedness of the

  4. Effectiveness of Cognitive-Behavioral Therapy and Physical Therapy for Provoked Vestibulodynia: A Randomized Pilot Study.

    Science.gov (United States)

    Goldfinger, Corrie; Pukall, Caroline F; Thibault-Gagnon, Stephanie; McLean, Linda; Chamberlain, Susan

    2016-01-01

    Non-medical and non-surgical treatments for provoked vestibulodynia target psychological, sexual, and pelvic floor muscle factors that maintain the condition. The goal of the study was to compare the effects of cognitive-behavioral therapy (CBT) and physical therapy (PT) on pain and psychosexual outcomes in women with provoked vestibulodynia. In a clinical trial, 20 women with provoked vestibulodynia were randomly assigned to receive CBT or comprehensive PT. Participants were assessed before treatment, after treatment, and at 6-month follow-up by gynecologic examination, structured interviews, and standardized questionnaires measuring pain, psychological, and sexual variables. Outcome measurements were based on an adaptation of the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials recommendations. The primary outcome was change in intercourse pain intensity. Secondary outcomes included pain during the cotton swab test, pain with various sexual and non-sexual activities, and sexual functioning and negative pain cognitions. The two treatment groups demonstrated significant decreases in vulvar pain during sexual intercourse, with 70% and 80% of participants in the CBT and PT groups demonstrating a moderate clinically important decrease in pain (≥30%) after treatment. Participants in the two groups also had significant improvements in pain during the gynecologic examination, the percentage of painful intercourse attempts, the percentage of activities resulting in pain, and the ability to continue intercourse without stopping because of pain. Psychological outcomes, including pain catastrophizing and perceived control over pain, also showed improvement in the two groups. Significant improvements in sexual functioning were observed only in participants who completed CBT. Few between-group differences were identified other than the PT group showing earlier improvements in some outcomes. Nearly all improvements were maintained at the 6-month

  5. Modelling the influence of thermal effects induced by radio frequency electric field on the dynamics of the ATPase nano-biomolecular motors.

    Science.gov (United States)

    Lohrasebi, A; Mohamadi, S; Fadaie, S; Rafii-Tabar, H

    2012-07-01

    We model the dynamics of the F(0) component of the F(0)F(1)-ATPase mitochondrion-based nano-motor operating in a stochastically-fluctuating medium that represents the intracellular environment. The stochastic dynamics are modeled via Langevin equation of motion wherein fluctuations are treated as white noise. We have investigated the influence of an applied alternating electric field on the rotary motion of the F(0) rotor in such an environment. The exposure to the field induces a temperature rise in the mitochondrion's membrane, within which the F(0) is embedded. The external field also induces an electric potential that promotes a change in the mitochondrion's transmembrane potential (TMP). Both the induced temperature and the change in TMP contribute to a change in the dynamics of the F(0). We have found that for external fields in the radio frequency (RF) range, normally present in the environment and encountered by biological systems, the contribution of the induced thermal effects, relative to that of the induced TMP, to the dynamics of the F(0) is more significant. The changes in the dynamics of the F(0) part affect the frequency of the rotary motion of the F(0)F(1)-ATPase protein motor which, in turn, affects the production rate of the ATP molecules. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  6. Do psychosexual factors play a role in the etiology of provoked vestibulodynia? A critical review.

    Science.gov (United States)

    Desrochers, Geneviève; Bergeron, Sophie; Landry, Tina; Jodoin, Mélanie

    2008-01-01

    The aim of this review was to critically examine published studies concerning the psychosexual aspects of provoked vestibulodynia. Despite the presence of several methodological limitations, some findings were consistently replicated. Overall, women with vestibulodynia demonstrate impaired sexual functioning, namely, lower levels of sexual desire, arousal, and frequency of intercourse. Childhood physical and sexual abuse represent potential risk factors for the development of this condition. Additionally, specific psychological states such as anxiety, fear of pain, hypervigilance, catastrophizing, and depression, are more frequently reported by these women. More rigorous studies are needed to establish which psychosexual variables may exacerbate and/or maintain vestibulodynia.

  7. Epilepsy provoked by television and video games: safety of 100-Hz screens.

    Science.gov (United States)

    Ricci, S; Vigevano, F; Manfredi, M; Kasteleijn-Nolst Trenité, D G

    1998-03-01

    Television (TV) and video games (VG) can provoke seizures in patients with photosensitive epilepsies. Flicker frequency is the most important factor in screen activation. We tested conventional 50-Hz versus 100-Hz monitors during TV viewing and VG playing in 30 photosensitive subjects, 23 of whom had a history of TV or VG seizures or both. Fifteen subjects' discharges were activated by 50-Hz TV; 17 by 50-Hz VG; and one by a 100-Hz screen. Thus, 100-Hz screens protect against screen activation.

  8. Spatio-temporal dynamics of kind versus hostile intentions in the human brain: An electrical neuroimaging study.

    Science.gov (United States)

    Wang, Yiwen; Huang, Liang; Zhang, Wei; Zhang, Zhen; Cacioppo, Stephanie

    2015-01-01

    Neuroscience research suggests that inferring neutral intentions of other people recruits a specific brain network within the inferior fronto-parietal action observation network as well as a putative social network including brain areas subserving theory of mind, such as the posterior superior temporal sulcus (pSTS), the temporo-parietal junction (TPJ), and also the anterior cingulate cortex (ACC). Recent studies on harmful intentions have refined this network by showing the specific involvement of the ACC, amygdala, and ventromedial prefrontal cortex (vmPFC) in early stages (within 200 ms) of information processing. However, the functional dynamics for kind intentions within and among these networks remains unclear. To address this question, we measured electrical brain activity from 18 healthy adult participants while they were performing an intention inference task with three different types of intentions: kind, hostile and non-interactive. Electrophysiological results revealed that kind intentions were characterized by significantly larger peak amplitudes of N2 over the frontal sites than those for hostile and non-interactive intentions. On the other hand, there were no significant differences between hostile and non-interactive intentions at N2. The source analysis suggested that the vicinity of the left cingulate gyrus contributed to the N2 effect by subtracting the kindness condition from the non-interactive condition within 250-350 ms. At a later stage (i.e., during the 270-500 ms epoch), the peak amplitude of the P3 over the parietal sites and the right hemisphere was significantly larger for hostile intentions compared to the kind and non-interactive intentions. No significant differences were observed at P3 between kind and non-interactive intentions. The source analysis showed that the vicinity of the left anterior cingulate cortex contributed to the P3 effect by subtracting the hostility condition from the non-interactive condition within 450-550 ms

  9. A Comparison of Electromagnetic Induction and Electrical Resistivity Tomography Techniques for Monitoring of Shallow Soil Moisture Dynamics

    Science.gov (United States)

    Endres, A. L.; Toy, C.; Van-Lane, P. R.; Campbell, W. J.; Steelman, C. M.

    2014-12-01

    While the capacity of both electromagnetic induction (EMI) and electrical resistivity tomography (ERT) to monitor shallow soil moisture dynamics has been extensively examined, there have been few studies comparing the results of these two techniques. These comparative studies have primarily treated ERT as the more reliable method and focussed on the potential shortcoming (i.e., calibration and stability) of EMI devices. Further, these studies have been very limited in terms of their duration and the range of soil moisture conditions observed. Concurrent EMI and ERT surveys we acquired during a 36-month period to monitor changes in shallow moisture conditions at a clayey vineyard located in Vineland, Ontario, Canada is an excellent data set for such a comparison between these geoelectrical techniques. A wide range of soil moisture conditions were encountered during this monitoring program including wet spring and fall, dry summer, and frozen winter periods. Also, the effects of variations in hydrological processes between contrasting annual cycles (e.g., wet versus dry summer conditions) can be seen in these hydrogeophysical data. In addition, procedures were followed during the EMI data acquisition to minimize calibration and stability issues. We found very good agreement between these two geoelectrical techniques during the relatively wet conditions during fall to spring period. However, there is significant deviation between these methods during the summer period with the EMI data indicating less conductive (i.e., drier) conditions than the ERT data. This deviation is larger for the EMI horizontal dipole data, indicating that the source of this discrepancy is located in shallow near-surface. In addition, the comparison of gravimetric soil moisture measurements with both geoelectrical data sets shows a substantially better correlation between soil moisture and the EMI data, implying that there are significant limitations with the ERT technique in this application

  10. Effects of electrocautery to provoke endovascular thermal injury Efeitos do eletrocautério para provocar lesão térmica endovascular

    Directory of Open Access Journals (Sweden)

    Fabio Henrique Rossi

    2011-10-01

    Full Text Available PURPOSE: To investigate the effects of a new electrocautery device to provoke endovascular venous thermal injury. METHODS: An experimental endovascular electrocautery was placed inside eight ex-vivo bovine saphenous veins models. Each one was divided in eight segments and progressive intensities of electric energy liberated. The macroscopic and microscopic effects were analyzed. RESULTS: Forty bovine saphenous veins segments were studied. The higher the electric energy applied the greater the nuclear picnosis and more intense the cytoplasmatic shrinkage and electrocoagulation effects. CONCLUSION: The experimental endovascular electrocautery device demonstrated to be both capable of inducing the destruction of the intimal layers of the studied vein model and provoke endovascular thermal injury.OBJETIVO: Investigar os efeitos de um modelo experimental de eletrocautério em provocar lesão venosa térmica endovascular. MÉTODOS: O eletrocautério endovascular foi colocado dentro de oito modelos experimentais de veia safena bovina. Cada uma foi dividida em oito segmentos e intensidades progressivas de energia elétrica liberada. Os efeitos macroscópicos e microscópicos foram analisados. RESULTADOS: Foram estudados quarenta segmentos de veia safena bovina. Quanto maior a energia elétrica aplicada pelo eletrocauterizador endovascular maiores foram as alteraçoes de picnose nuclear e mais intensa a retração citoplasmática observada. CONCLUSÃO: O eletrocautério endovascular experimental demonstrou ser capaz de induzir a destruição da camada íntima e provocar lesão térmica endovascular.

  11. Synergism between endotoxin priming and exotoxin challenge in provoking severe vascular leakage in rabbit lungs.

    Science.gov (United States)

    Schütte, H; Rosseau, S; Czymek, R; Ermert, L; Walmrath, D; Krämer, H J; Seeger, W; Grimminger, F

    1997-09-01

    Lipopolysaccharides (LPS) of gram-negative bacteria prime rabbit lungs for enhanced thromboxane-mediated vasoconstriction upon subsequent challenge with the exotoxin Escherichia coli hemolysin (HlyA) (Walmrath et al. J. Exp. Med. 1994;180:1437-1443). We investigated the impact of endotoxin priming and subsequent HlyA challenge on lung vascular permeability while maintaining constancy of capillary pressure. Rabbit lungs were perfused in a pressure-controlled mode in the presence of the thromboxane receptor antagonist BM 13.505, with continuous monitoring of flow. Perfusion for 180 min with 10 ng/ml LPS did not provoke vasoconstriction or alteration of capillary filtration coefficient (Kfc) values. HlyA (0.021 hemolytic units/ml) induced thromboxane release and a transient decrease in perfusion flow in the absence of significant changes in Kfc. Similar results were obtained when LPS and HlyA were coapplied simultaneously. However, when the HlyA challenge was undertaken after 180 min of LPS priming, a manifold increase in Kfc values was noted, with concomitant severe lung edema formation, although capillary pressure remained unchanged. Thus, endotoxin primes the lung vasculature to respond with a severe increase in vascular permeability to a subsequent low-dose application of HlyA. Such synergism between endotoxin priming and exotoxin challenge in provoking lung vascular leakage may contribute to the pathogenesis of respiratory failure in sepsis and severe lung infection.

  12. Beer flavor provokes striatal dopamine release in male drinkers: mediation by family history of alcoholism.

    Science.gov (United States)

    Oberlin, Brandon G; Dzemidzic, Mario; Tran, Stella M; Soeurt, Christina M; Albrecht, Daniel S; Yoder, Karmen K; Kareken, David A

    2013-08-01

    Striatal dopamine (DA) is increased by virtually all drugs of abuse, including alcohol. However, drug-associated cues are also known to provoke striatal DA transmission- a phenomenon linked to the motivated behaviors associated with addiction. To our knowledge, no one has tested if alcohol's classically conditioned flavor cues, in the absence of a significant pharmacologic effect, are capable of eliciting striatal DA release in humans. Employing positron emission tomography (PET), we hypothesized that beer's flavor alone can reduce the binding potential (BP) of [(11)C]raclopride (RAC; a reflection of striatal DA release) in the ventral striatum, relative to an appetitive flavor control. Forty-nine men, ranging from social to heavy drinking, mean age 25, with a varied family history of alcoholism underwent two [(11)C]RAC PET scans: one while tasting beer, and one while tasting Gatorade. Relative to the control flavor of Gatorade, beer flavor significantly increased self-reported desire to drink, and reduced [(11)C]RAC BP, indicating that the alcohol-associated flavor cues induced DA release. BP reductions were strongest in subjects with first-degree alcoholic relatives. These results demonstrate that alcohol-conditioned flavor cues can provoke ventral striatal DA release, absent significant pharmacologic effects, and that the response is strongest in subjects with a greater genetic risk for alcoholism. Striatal DA responses to salient alcohol cues may thus be an inherited risk factor for alcoholism.

  13. Practical implementation of the concept of converted electric vehicle with advanced traction and dynamic performance and environmental safety indicators

    Science.gov (United States)

    Sidorov, K. M.; Yutt, V. E.; Grishchenko, A. G.; Golubchik, T. V.

    2018-02-01

    The objective of the work presented in this paper is to describe the implementation of the technical solutions have been developed, with regard to structure, composition, and characteristics, for an experimental prototype of an electric vehicle which has been converted from a conventional vehicle. The methodology of the study results is based on the practical implementation of the developed concept of the conversion of conventional vehicles into electric vehicles. The main components of electric propulsion system of the experimental prototype of electric vehicle are developed and manufactured on the basis of computational researches, taking into account the criteria and principles of conversion within the framework of presented work. The article describes a schematic and a design of power conversion and commutation electrical equipment, traction battery, electromechanical transmission. These results can serve as guidance material in the design and implementation of electric propulsion system (EPS) components of electric vehicles, facilitate the development of optimal technical solutions in the development and manufacture of vehicles, including those aimed at autonomy of operation and the use of perspective driver assistance systems. As part of this work, was suggested a rational structure for an electric vehicle experimental prototype, including technical performance characteristics of the components of EPS.

  14. Swift heavy ion provoked structural, optical and electrical properties in SnO{sub 2} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Abhirami, K.M.; Matheswaran, P.; Gokul, B.; Sathyamoorthy, R. [Kongunadu Arts and Science College, PG and Research Department of Physics, Coimbatore, Tamilnadu (India); Asokan, K. [Inter University Accelerator Centre, Materials Science Division, New Delhi (India)

    2013-06-15

    SnO{sub 2} thin films grown on glass substrates at 300 {sup circle} C by reactive thermal evaporation and annealed at 600 {sup circle} C were irradiated by 120 MeV Ag{sup 9+} ions. Though irradiation is known to induce lattice disorder and suppression of crystallinity, we observe grain growth at a certain fluence of irradiation. X-ray diffraction (XRD) revealed the crystalline nature of the films. The particle size estimated by Scherrer's formula for the irradiated films was in the range 10-25 nm. The crystallite size increases with increase in fluence up to 1 x 10{sup 12} ions cm{sup -2}, whereas after that the size starts decreasing. Atomic force microscope (AFM) results showed the surface modification of nanostructures for films irradiated with fluences of 1 x 10{sup 11} ions cm{sup -2} to 1 x 10{sup 13} ions cm{sup -2}. The UV-visible spectrum showed the band gap of the irradiated films in the range of 3.56 eV-3.95 eV. The resistivity decreases with fluence up to 5 x 10{sup 12} ions cm{sup -2} and starts increasing after that. Rutherford Backscattering (RBS) reveals the composition of the films and sputtering of ions due to irradiation at higher fluence. (orig.)

  15. Experimental activation of the sphenopalatine ganglion provokes cluster-like attacks in humans

    DEFF Research Database (Denmark)

    Schytz, Henrik W; Barløse, Mads; Guo, Song

    2013-01-01

    BackgroundHigh frequency (HF) stimulation of the sphenopalatine ganglion (SPG) is an emerging abortive treatment for cluster headache (CH) attacks. HF SPG stimulation is thought to exert its effect by physiologically blocking parasympathetic outflow. We hypothesized that low frequency (LF) SPG...... stimulation may activate the SPG, causing increased parasympathetic outflow and thereby provoking cluster attacks in CH patients.MethodsIn a double-blind randomized cross-over study, seven CH patients implanted with an SPG neurostimulator were randomly allocated to receive HF or LF stimulation for 3 min on 2...... separate days. We recorded headache characteristics and autonomic symptoms during and after stimulation.ResultsSix patients completed the study. Three out of six patients (50%) reported ipsilateral cluster-like attacks during or within 30 min of LF SPG stimulation. These cluster-like attacks were all...

  16. Understanding the Uncanny: Both Atypical Features and Category Ambiguity Provoke Aversion toward Humanlike Robots

    Science.gov (United States)

    Strait, Megan K.; Floerke, Victoria A.; Ju, Wendy; Maddox, Keith; Remedios, Jessica D.; Jung, Malte F.; Urry, Heather L.

    2017-01-01

    Robots intended for social contexts are often designed with explicit humanlike attributes in order to facilitate their reception by (and communication with) people. However, observation of an “uncanny valley”—a phenomenon in which highly humanlike entities provoke aversion in human observers—has lead some to caution against this practice. Both of these contrasting perspectives on the anthropomorphic design of social robots find some support in empirical investigations to date. Yet, owing to outstanding empirical limitations and theoretical disputes, the uncanny valley and its implications for human-robot interaction remains poorly understood. We thus explored the relationship between human similarity and people's aversion toward humanlike robots via manipulation of the agents' appearances. To that end, we employed a picture-viewing task (Nagents = 60) to conduct an experimental test (Nparticipants = 72) of the uncanny valley's existence and the visual features that cause certain humanlike robots to be unnerving. Across the levels of human similarity, we further manipulated agent appearance on two dimensions, typicality (prototypic, atypical, and ambiguous) and agent identity (robot, person), and measured participants' aversion using both subjective and behavioral indices. Our findings were as follows: (1) Further substantiating its existence, the data show a clear and consistent uncanny valley in the current design space of humanoid robots. (2) Both category ambiguity, and more so, atypicalities provoke aversive responding, thus shedding light on the visual factors that drive people's discomfort. (3) Use of the Negative Attitudes toward Robots Scale did not reveal any significant relationships between people's pre-existing attitudes toward humanlike robots and their aversive responding—suggesting positive exposure and/or additional experience with robots is unlikely to affect the occurrence of an uncanny valley effect in humanoid robotics. This work

  17. Sexual arousal in women with provoked vestibulodynia: the application of laser Doppler imaging to sexual pain.

    Science.gov (United States)

    Boyer, Stéphanie C; Pukall, Caroline F; Chamberlain, Susan M

    2013-04-01

    Introduction.  Women with provoked vestibulodynia (PVD) report lower sexual arousal than nonaffected women, however, laboratory studies of arousal have reported contradictory results about whether group differences exist in genital and subjective arousal. Aim.  To examine genital and subjective sexual arousal in women with and without PVD. Methods.  Eligible women with and without PVD (N = 42) attended a laboratory session that included an interview, questionnaire completion, and genital imaging. A direct measure of superficial blood flow-laser Doppler imaging-was used to assess vulvar blood flow levels while participants watched three films, including an erotic film. Participants answered questions about their level of sexual arousal before, during, and after the erotic film. Main Outcome Measures.  Average vulvar blood flow levels during the baseline and erotic films, numerical ratings of subjective sexual arousal and anxiety, as well as questionnaire measures of arousal. Results.  There was a significant group difference in genital arousal, whereby the PVD group showed a lower genital response to the erotic film, as well as a significant interaction between baseline blood flow and group membership. Separate group regression analyses demonstrated that baseline blood flow explained a substantial amount of the variance in erotic film blood flow in the control group (70%), while only 27% was explained by this variable in the PVD group. There were no differences in subjective sexual arousal or anxiety between the groups. Across questionnaire measures, women with PVD reported lower sexual arousal than the control group. Conclusions.  The results suggest that women with PVD show lower genital responsiveness than nonaffected women to sexual stimuli in a laboratory setting and that their genital arousal is likely impacted by a number of biopsychosocial factors. Boyer SC, Pukall CF, and Chamberlain SM. Sexual arousal in women with provoked vestibulodynia

  18. Understanding the Uncanny: Both Atypical Features and Category Ambiguity Provoke Aversion toward Humanlike Robots.

    Science.gov (United States)

    Strait, Megan K; Floerke, Victoria A; Ju, Wendy; Maddox, Keith; Remedios, Jessica D; Jung, Malte F; Urry, Heather L

    2017-01-01

    Robots intended for social contexts are often designed with explicit humanlike attributes in order to facilitate their reception by (and communication with) people. However, observation of an "uncanny valley"-a phenomenon in which highly humanlike entities provoke aversion in human observers-has lead some to caution against this practice. Both of these contrasting perspectives on the anthropomorphic design of social robots find some support in empirical investigations to date. Yet, owing to outstanding empirical limitations and theoretical disputes, the uncanny valley and its implications for human-robot interaction remains poorly understood. We thus explored the relationship between human similarity and people's aversion toward humanlike robots via manipulation of the agents' appearances. To that end, we employed a picture-viewing task ( N agents = 60) to conduct an experimental test ( N participants = 72) of the uncanny valley's existence and the visual features that cause certain humanlike robots to be unnerving. Across the levels of human similarity, we further manipulated agent appearance on two dimensions, typicality (prototypic, atypical, and ambiguous) and agent identity (robot, person), and measured participants' aversion using both subjective and behavioral indices. Our findings were as follows: (1) Further substantiating its existence, the data show a clear and consistent uncanny valley in the current design space of humanoid robots. (2) Both category ambiguity, and more so, atypicalities provoke aversive responding, thus shedding light on the visual factors that drive people's discomfort. (3) Use of the Negative Attitudes toward Robots Scale did not reveal any significant relationships between people's pre-existing attitudes toward humanlike robots and their aversive responding-suggesting positive exposure and/or additional experience with robots is unlikely to affect the occurrence of an uncanny valley effect in humanoid robotics. This work furthers

  19. The abdominal compartment syndrome as a second insult during systemic neutrophil priming provokes multiple organ injury.

    Science.gov (United States)

    Rezende-Neto, Joao B; Moore, Ernest E; Masuno, Tomohiko; Moore, Peter K; Johnson, Jeffrey L; Sheppard, Forest R; Cunha-Melo, Jose R; Silliman, Christopher C

    2003-10-01

    In our recent clinical study of damage control laparotomy, the abdominal compartment syndrome (ACS) emerged as an independent risk factor for postinjury multiple organ failure (MOF). We and others have shown previously that the ACS promotes the systemic production of proinflammatory cytokines. Our study objective was to develop a clinically relevant two-event animal model of postinjury MOF using the ACS as a second insult during systemic neutrophil priming to provoke organ dysfunction. Male adult rats underwent hemorrhagic shock (30 mmHg x 45 min) and were resuscitated with crystalloids and shed blood. The timing of postshock systemic neutrophil (PMN) priming was determined by the surface expression of CD11b via flow cytometry. Finding maximal PMN priming at 8 h, but no priming at 2 h (early) and 18 h (late), the ACS (25 mmHg x 60 min) was introduced at these time points. At 24 h postshock, lung injury was assessed by lung elastase concentration and Evans blue dye extravasation in bronchoalveolar lavage. Liver and renal injuries were determined by serum alanine aminotransferase, serum creatinine, and blood urea nitrogen. The ACS during the time of maximal systemic PMN priming (8 h) provoked lung and liver injury, but did not if introduced at 2 or 18 h postshock when there was no evidence of systemic PMN priming. The 24-h mortality of this two-event model was 33%. These findings corroborate the potential for the ACS to promote multiple organ injury when occurring at the time of systemic PMN priming. This clinically relevant two-event animal model of PMN organ injury may be useful in elucidating therapy strategies to prevent postinjury MOF.

  20. Understanding the Uncanny: Both Atypical Features and Category Ambiguity Provoke Aversion toward Humanlike Robots

    Directory of Open Access Journals (Sweden)

    Megan K. Strait

    2017-08-01

    Full Text Available Robots intended for social contexts are often designed with explicit humanlike attributes in order to facilitate their reception by (and communication with people. However, observation of an “uncanny valley”—a phenomenon in which highly humanlike entities provoke aversion in human observers—has lead some to caution against this practice. Both of these contrasting perspectives on the anthropomorphic design of social robots find some support in empirical investigations to date. Yet, owing to outstanding empirical limitations and theoretical disputes, the uncanny valley and its implications for human-robot interaction remains poorly understood. We thus explored the relationship between human similarity and people's aversion toward humanlike robots via manipulation of the agents' appearances. To that end, we employed a picture-viewing task (Nagents = 60 to conduct an experimental test (Nparticipants = 72 of the uncanny valley's existence and the visual features that cause certain humanlike robots to be unnerving. Across the levels of human similarity, we further manipulated agent appearance on two dimensions, typicality (prototypic, atypical, and ambiguous and agent identity (robot, person, and measured participants' aversion using both subjective and behavioral indices. Our findings were as follows: (1 Further substantiating its existence, the data show a clear and consistent uncanny valley in the current design space of humanoid robots. (2 Both category ambiguity, and more so, atypicalities provoke aversive responding, thus shedding light on the visual factors that drive people's discomfort. (3 Use of the Negative Attitudes toward Robots Scale did not reveal any significant relationships between people's pre-existing attitudes toward humanlike robots and their aversive responding—suggesting positive exposure and/or additional experience with robots is unlikely to affect the occurrence of an uncanny valley effect in humanoid robotics

  1. Dynamics of risk management in the regulated contracting environment of the Brazilian electrical sector; Dinamica da gestao de riscos no ambiente de contratacao regulada do setor eletrico brasileiro

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fabio Cavaliere de

    2008-11-15

    This thesis analyses the dynamics of risk management in the regulated contracting environment of the Brazilian electrical sector. As in the new model the distribution utilities are obliged to ensure energy contracting to supply their whole markets, these companies became exposed to volume risks related to the demand uncertainties. So the new model following similar directives from the first phase developed management tools to mitigate the new risks mentioned above. As in a well structured market it is expected that the risks should be evenly shared or that risk management tools should be provided for all, this work intended to analyze the dynamics of the designed mechanisms and their impacts over the regulated market. In this work the risks of the electricity markets are studied and the management tools devised for the Brazilian market are identified. Finally for understanding the dynamics a thorough analysis of the auctions, of the mechanism for compensation of surplus and deficits and tariffs are carried on. The results show that the management tools were regularly employed by distribution companies, but the risks were merely transferred to the captive customers leading to distortions and asymmetries that conflict with the basis that guided the second phase of the reform. The work proposes remedial actions to mitigate the observed impacts and to provide risk management tools to the captive customer. (author)

  2. Load-shift incentives for household demand response: Evaluation of hourly dynamic pricing and rebate schemes in a wind-based electricity system

    DEFF Research Database (Denmark)

    Katz, Jonas; Møller Andersen, Frits; Morthorst, Poul Erik

    2016-01-01

    Applying a partial equilibrium model of the electricity market we analyse effects of exposing household electricity customers to retail products with variable pricing. Both short-term and long-term effects of exposing customers to hourly spot market prices and a simpler rebate scheme are analysed...... under scenarios with large shares of wind power in a Danish case study. Our results indicate strategies that could be favourable in ensuring high adoption of products and efficient response by households. We find that simple pricing schemes, though economically less efficient, could become important...... in an early phase to initialise the development of household demand response. At a later point, when long-term dynamics take effect, a larger effort should be made to shift consumers onto real-time rates, and an increased focus on overall adoption of variable pricing will be required. Another finding...

  3. Investigating a green economy transition of the electricity sector in the Western Cape province of South Africa: a system dynamics approach

    Directory of Open Access Journals (Sweden)

    Oosthuizen, Juan

    2016-12-01

    Full Text Available The Western Cape Government in South Africa has identified the concept of a green economy as a way to transform the Province’s economy to one that is more sustainable from an economic, social, and environmental perspective. System dynamics modelling was used to develop a better understanding of the implications of different green economy policies and investments in the electricity sector of the Western Cape Province. The results suggest that continuing on the current policy path would increase the gap between demand and supply, increase the carbon footprint of the electricity sector, and not provide growth in employment in the sector. Strategic green economy investments are therefore expected to impact positively on a number of indicators across a number of sectors.

  4. A quantum mechanics/molecular dynamics study of electric field gradient fluctuations in the liquid phase. The case of Na+ in aqueous solution.

    Science.gov (United States)

    Aidas, Kęstutis; Ågren, Hans; Kongsted, Jacob; Laaksonen, Aatto; Mocci, Francesca

    2013-02-07

    The (23)Na quadrupolar coupling constant of the Na(+) ion in aqueous solution has been predicted using molecular dynamics simulations and hybrid quantum mechanics/molecular mechanics methods for the calculation of electric field gradients. The developed computational approach is generally expected to provide reliable estimates of the quadrupolar coupling constants of monoatomic species in condensed phases, and we show here that intermolecular polarization and non-electrostatic interactions are of crucial importance as they result in a 100% increased quadrupolar coupling constant of the ion as compared to a simpler pure electrostatic picture. These findings question the reliability of the commonly applied classical Sternheimer approximation for the calculations of the electric field gradient. As it can be expected from symmetry considerations, the quadrupolar coupling constants of the 5- and 6-coordinated Na(+) ions in solution are found to differ significantly.

  5. Static and dynamic components in the vascular myogenic response to passive changes in length as revealed by electrical and mechanical recordings from the rat portal vein.

    Science.gov (United States)

    Johansson, B; Mellander, S

    1975-01-01

    The effects of static and dynamic passive stretch and shortening on electrical activity and active force were analyzed in the isolated rat portal vein. Static stretch by 40% of muscle length evoked moderate excitatory effects with enhanced mechanical activity and an average increase in spike discharge of 12% above the control value of 55 plus or minus 2.6 spikes/min. The dynamic responses studied at various rates of length change (dL/dt) over the range between minus 12 and plus 12 mm/min, i.e., minus 3 and plus 3% muscle length/sec, were much more pronounced. Active force and spike activity showed graded increases with increasing rates of stretch. The electrical activity reached a value of 180 spikes/min (approximately equal to 325% of control) at 5 mm/min; this frequency was then maintained for stretch rates up to 12 mm/min. Mechanical activity during stretch was further reinforced by the shift along the length-tension diagram. Passive shortening at rates from minus 1 to minus 12 mm/min caused graded decreases in mechanical and electrical activity below the control levels, complete inhibition being observed at the latter dL/dt. Blockade of alpha and beta receptors indicated that the responses were myogenic in nature. The findings seem to provide direct support for the myogenic hypothesis of vascular tone and responses to stretch of the vascular wall, but they indicate that emphasis should be placed on the dynamic characteristics of the stimulus rather than its static nature. This emphasis constitutes a new concept in the myogenic control of the peripheral circulation.

  6. Referred Pain Patterns Provoked on Intra-Pelvic Structures among Women with and without Chronic Pelvic Pain: A Descriptive Study

    Science.gov (United States)

    Butler, Stephen; Peterson, Magnus; Eriksson, Margaretha

    2015-01-01

    Objectives To describe referred pain patterns provoked from intra-pelvic structures in women with chronic pelvic pain (CPP) persisting after childbirth with the purpose to improve diagnostics and give implications for treatment. Materials and Methods In this descriptive and comparative study 36 parous women with CPP were recruited from a physiotherapy department waiting list and by advertisements in newspapers. A control group of 29 parous women without CPP was consecutively assessed for eligibility from a midwifery surgery. Inclusion criterion for CPP was: moderate pain in the sacral region persisting at least six months after childbirth confirmed by pelvic pain provocation tests. Exclusion criteria in groups with and without CPP were: persistent back or pelvic pain with onset prior to pregnancy, previous back surgery and positive neurological signs. Pain was provoked by palpation of 13 predetermined intra-pelvic anatomical landmarks. The referred pain distribution was expressed in pain drawings and described in pain maps and calculated referred pain areas. Results Pain provoked by palpation of the posterior intra-pelvic landmarks was mostly referred to the sacral region and pain provoked by palpation of the ischial and pubic bones was mostly referred to the groin and pubic regions, with or without pain referred down the ipsilateral leg. The average pain distribution area provoked by palpation of all 13 anatomical landmarks was 30.3 mm² (19.2 to 53.7) in women with CPP as compared to 3.2 mm² (1.0 to 5.1) in women without CPP, ppain patterns provoked from intra-pelvic landmarks in women with CPP are consistent with sclerotomal sensory innervation. Magnification of referred pain patterns indicates allodynia and central sensitization. The results suggest that pain mapping can be used to evaluate and confirm the pain experience among women with CPP and contribute to diagnosis. PMID:25793999

  7. Referred pain patterns provoked on intra-pelvic structures among women with and without chronic pelvic pain: a descriptive study.

    Directory of Open Access Journals (Sweden)

    Thomas Torstensson

    Full Text Available To describe referred pain patterns provoked from intra-pelvic structures in women with chronic pelvic pain (CPP persisting after childbirth with the purpose to improve diagnostics and give implications for treatment.In this descriptive and comparative study 36 parous women with CPP were recruited from a physiotherapy department waiting list and by advertisements in newspapers. A control group of 29 parous women without CPP was consecutively assessed for eligibility from a midwifery surgery. Inclusion criterion for CPP was: moderate pain in the sacral region persisting at least six months after childbirth confirmed by pelvic pain provocation tests. Exclusion criteria in groups with and without CPP were: persistent back or pelvic pain with onset prior to pregnancy, previous back surgery and positive neurological signs. Pain was provoked by palpation of 13 predetermined intra-pelvic anatomical landmarks. The referred pain distribution was expressed in pain drawings and described in pain maps and calculated referred pain areas.Pain provoked by palpation of the posterior intra-pelvic landmarks was mostly referred to the sacral region and pain provoked by palpation of the ischial and pubic bones was mostly referred to the groin and pubic regions, with or without pain referred down the ipsilateral leg. The average pain distribution area provoked by palpation of all 13 anatomical landmarks was 30.3 mm² (19.2 to 53.7 in women with CPP as compared to 3.2 mm² (1.0 to 5.1 in women without CPP, p< 0.0001.Referred pain patterns provoked from intra-pelvic landmarks in women with CPP are consistent with sclerotomal sensory innervation. Magnification of referred pain patterns indicates allodynia and central sensitization. The results suggest that pain mapping can be used to evaluate and confirm the pain experience among women with CPP and contribute to diagnosis.

  8. Referred pain patterns provoked on intra-pelvic structures among women with and without chronic pelvic pain: a descriptive study.

    Science.gov (United States)

    Torstensson, Thomas; Butler, Stephen; Lindgren, Anne; Peterson, Magnus; Eriksson, Margaretha; Kristiansson, Per

    2015-01-01

    To describe referred pain patterns provoked from intra-pelvic structures in women with chronic pelvic pain (CPP) persisting after childbirth with the purpose to improve diagnostics and give implications for treatment. In this descriptive and comparative study 36 parous women with CPP were recruited from a physiotherapy department waiting list and by advertisements in newspapers. A control group of 29 parous women without CPP was consecutively assessed for eligibility from a midwifery surgery. Inclusion criterion for CPP was: moderate pain in the sacral region persisting at least six months after childbirth confirmed by pelvic pain provocation tests. Exclusion criteria in groups with and without CPP were: persistent back or pelvic pain with onset prior to pregnancy, previous back surgery and positive neurological signs. Pain was provoked by palpation of 13 predetermined intra-pelvic anatomical landmarks. The referred pain distribution was expressed in pain drawings and described in pain maps and calculated referred pain areas. Pain provoked by palpation of the posterior intra-pelvic landmarks was mostly referred to the sacral region and pain provoked by palpation of the ischial and pubic bones was mostly referred to the groin and pubic regions, with or without pain referred down the ipsilateral leg. The average pain distribution area provoked by palpation of all 13 anatomical landmarks was 30.3 mm² (19.2 to 53.7) in women with CPP as compared to 3.2 mm² (1.0 to 5.1) in women without CPP, ppain patterns provoked from intra-pelvic landmarks in women with CPP are consistent with sclerotomal sensory innervation. Magnification of referred pain patterns indicates allodynia and central sensitization. The results suggest that pain mapping can be used to evaluate and confirm the pain experience among women with CPP and contribute to diagnosis.

  9. Steady-state and dynamic evaluation of the electric propulsion system test bed vehicle on a road load simulator

    Science.gov (United States)

    Dustin, M. O.

    1983-01-01

    The propulsion system of the Lewis Research Center's electric propulsion system test bed vehicle was tested on the road load simulator under the DOE Electric and Hybrid Vehicle Program. This propulsion system, consisting of a series-wound dc motor controlled by an infinitely variable SCR chopper and an 84-V battery pack, is typical of those used in electric vehicles made in 1976. Steady-state tests were conducted over a wide range of differential output torques and vehicle speeds. Efficiencies of all of the components were determined. Effects of temperature and voltage variations on the motor and the effect of voltage changes on the controller were examined. Energy consumption and energy efficiency for the system were determined over the B and C driving schedules of the SAE J227a test procedure.

  10. SILHIL Replication of Electric Aircraft Powertrain Dynamics and Inner-Loop Control for V&V of System Health Management Routines

    Science.gov (United States)

    Bole, Brian; Teubert, Christopher Allen; Cuong Chi, Quach; Hogge, Edward; Vazquez, Sixto; Goebel, Kai; George, Vachtsevanos

    2013-01-01

    Software-in-the-loop and Hardware-in-the-loop testing of failure prognostics and decision making tools for aircraft systems will facilitate more comprehensive and cost-effective testing than what is practical to conduct with flight tests. A framework is described for the offline recreation of dynamic loads on simulated or physical aircraft powertrain components based on a real-time simulation of airframe dynamics running on a flight simulator, an inner-loop flight control policy executed by either an autopilot routine or a human pilot, and a supervisory fault management control policy. The creation of an offline framework for verifying and validating supervisory failure prognostics and decision making routines is described for the example of battery charge depletion failure scenarios onboard a prototype electric unmanned aerial vehicle.

  11. Grid integration and smart grid implementation of emerging technologies in electric power systems through approximate dynamic programming

    OpenAIRE

    Xiao, Jingjie

    2013-01-01

    A key hurdle for implementing real-time pricing of electricity is a lack of con-sumers’ responses. Solutions to overcome the hurdle include the energy management system that automatically optimizes household appliance usage such as plug-in hybrid electric vehicle charging (and discharging with vehicle-to-grid) via a two-way com-munication with the grid. Real-time pricing, combined with household automation devices, has a potential to accommodate an increasing penetration of plug-in hybrid ele...

  12. Magnetospheric convection electric field dynamics andstormtime particle energization: case study of the magneticstorm of 4 May 1998

    Directory of Open Access Journals (Sweden)

    G. V. Khazanov

    2004-01-01

    Full Text Available It is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the L = 2 – 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference. Key words. Space plasma physics (charged particle motion and acceleration – Magnetospheric physics (electric fields, storms and substorms

  13. Magnetospheric convection electric field dynamics andstormtime particle energization: case study of the magneticstorm of 4 May 1998

    Directory of Open Access Journals (Sweden)

    G. V. Khazanov

    2004-01-01

    Full Text Available It is shown that narrow channels of high electric field are an effective mechanism for injecting plasma into the inner magnetosphere. Analytical expressions for the electric field cannot produce these channels of intense plasma flow, and thus, result in less entry and adiabatic energization of the plasma sheet into near-Earth space. For the ions, omission of these channels leads to an underprediction of the strength of the stormtime ring current and therefore, an underestimation of the geoeffectiveness of the storm event. For the electrons, omission of these channels leads to the inability to create a seed population of 10-100 keV electrons deep in the inner magnetosphere. These electrons can eventually be accelerated into MeV radiation belt particles. To examine this, the 1-7 May 1998 magnetic storm is studied with a plasma transport model by using three different convection electric field models: Volland-Stern, Weimer, and AMIE. It is found that the AMIE model can produce particle fluxes that are several orders of magnitude higher in the L = 2 – 4 range of the inner magnetosphere, even for a similar total cross-tail potential difference.

    Key words. Space plasma physics (charged particle motion and acceleration – Magnetospheric physics (electric fields, storms and substorms

  14. On-road magnetic emissions prediction of electric cars in terms of driving dynamics using neural networks

    NARCIS (Netherlands)

    Wefky, Ahmed M.; Espinosa, Felipe; Leferink, Frank Bernardus Johannes; Gardel, Alfredo; Vogt-Ardatjew, R.A.

    2013-01-01

    This paper presents a novel artificial neural network (ANN) model estimating vehicle-level radiated magnetic emissions of an electric car as a function of the corresponding driving pattern. Real world electromagnetic interference (EMI) experiments have been realized in a semi-anechoic chamber using

  15. Structure and dynamics of CaO films: A computational study of an effect of external static electric field

    Science.gov (United States)

    Kuklin, Mikhail S.; Bazhenov, Andrey S.; Honkala, Karoliina; Tosoni, Sergio; Pacchioni, Gianfranco; Häkkinen, Hannu

    2017-04-01

    Oxide films play a significant role in a wide range of industrial fields, mostly due to the thickness-dependent variation of their properties. Recently, it has been proposed based on the experimental study that carrier transport in CaO films proceeds via strong phonon excitations with a variable signal depending on the film thickness. In this paper, we report a detailed investigation in the frame of the density functional theory of structural and electronic properties of freestanding and Mo(100)-supported CaO films, as well as phonons therein, as functions of the film thickness and intensity of the external static electric field. Our calculations demonstrate that phonon frequencies negligibly depend on the external electric field. A small gradual increase of the energy of CaO phonons upon increase of the film thickness was found to be in line with earlier experimental findings. The effect of Mo support was observed in the systematic decrease of the energy of phonons. The applied electric field showed a minor effect on the structure of CaO films, whereas electronic properties of the oxide were significantly affected. In particular, the band gap of CaO films was found to gradually decrease with the growing intensity of the external electric field, while the effect is a more pronounced for thicker films. Overall, our paper provides innovative insights into the mechanism of electron transport and electronic properties of CaO films that might lead to new potential applications of oxide materials.

  16. Modeling and simulation of dielectrophoretic collective dynamics in a suspension of polarizable particles under the action of a gradient AC electric field.

    Science.gov (United States)

    Tada, Shigeru; Shen, Yan; Qiu, Zhiyong

    2017-06-01

    When a suspension of polarizable particles is subjected to a gradient AC electric field, the particles exhibit collective motion due to an interaction between the dipole induced in the particles and the spatial gradient of the electric field; this is known as dielectrophoresis. In the present study, the collective dynamics of suspended particles in a parallel-plate electric chamber was investigated by simulating numerically the trajectories of individual particles under the action of combined dielectrophoretic and dipole-dipole interparticle forces. The particles were transported by the dielectrophoretic forces toward the grounded electrodes. Before long, when the particles approached the site of the minimum field strength, attractive/repulsive interparticle forces became dominant and acted among the particles attempting to form a column-like cluster, having the particles distribution in concentric circles in its cross-section, in line with the centerline of the grounded electrodes. Our results also well reproduced the transient particle aggregation that was observed experimentally. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. In vivo PTH provokes apical NHE3 and NaPi2 redistribution and Na-K-ATPase inhibition

    DEFF Research Database (Denmark)

    Zhang, Y; Norian, J M; Magyar, C E

    1999-01-01

    The aim of this study was to test the hypothesis that in vivo administration of parathyroid hormone (PTH) provokes diuresis/natriuresis through redistribution of proximal tubule apical sodium cotransporters (NHE3 and NaPi2) to internal stores and inhibition of basolateral Na-K-ATPase activity and...

  18. Monoassociation of SCID mice with Helicobacter muridarum, but not four other enterics, provokes IBD upon receipt of T cells

    NARCIS (Netherlands)

    Jiang, HQ; Kushnir, N; Thurnheer, MC; Bos, NA; Cebra, JJ

    Background & Aims: Recently, a number of animal models for different aspects of inflammatory bowel disease (IBD) have been developed. The aim of this study was to use one of these to determine whether particular, ostensibly innocuous, intestinal bacteria could provoke or exacerbate IBD. Methods:

  19. Pelvic floor muscle function in women with provoked vestibulodynia and asymptomatic controls.

    Science.gov (United States)

    Næss, Ingrid; Bø, Kari

    2015-10-01

    The purpose of the present study was to assess vaginal resting pressure (VRP), pelvic floor muscle (PFM) strength and endurance, and surface EMG activity in women with and without provoked vestibulodynia (PVD). This was an assessor-masked comparison study including 70 women. Exclusion criteria were any previous pregnancy and presence of candida. Sensitivity of the vulvar vestibule was rated at three sites with Q-tip pressure measurement and a numerical rating scale for pain. VRP and PFM strength and endurance were measured with a high precision pressure transducer connected to a vaginal balloon. Pelvic floor muscle activity was measured with surface EMG. The independent samples t test was used to analyze differences between groups. The p value was set to VRP: 20.6 cmH2O (SD 7.1) versus controls: 17.3 cmH2O (SD 4.4), p = 0.02. The PVD group had significantly lower muscle activity during a 10-s holding period; PVD: 465.2 μV (SD 218.4), controls: 591.1 μV (SD 277.7), p = 0.04. Young, nulliparous women with PVD had significantly higher VRP, but this finding was not confirmed by vaginal surface EMG.

  20. Acute Administration of Diazepam Provokes Redox Homeostasis Imbalance in the Rat Brain: Prevention by Simvastatin.

    Science.gov (United States)

    Eger, Guilherme André; Ferreira, Vinícius Vialle; Batista, Camila Ribeiro; Bonde, Henrique LuisPetrek; de Lima, Daniela Delwing; Rodrigues, André Felipe; da Cruz, José Geraldo Pereira; Magro, Débora Delwing Dal

    2016-10-01

    We investigated the effects of acute diazepam (DZP) administration on thiobarbituric acid-reactive substance (TBARS) levels, protein carbonyl content, and on the activities of the antioxidant enzymes catalase, glutathione peroxidase, and superoxide dismutase in the brain of rats. Additionally, we investigated the antioxidant role of chronic pretreatment with simvastatin on the effects provoked by DZP. Simvastatin was administered (1 or 10 mg/kg by oral gavage) for 30 days. On the 30th day of treatment, groups were randomized and DZP was administered (0.5 or 1.0 mg/kg by intraperitoneal injection). Control groups received saline. Results showed that DZP enhanced TBARS levels and protein carbonyl content and altered enzymatic activity in the brain of rats. Simvastatin prevented most of the alterations caused by DZP on the oxidative stress parameters. Data indicate that DZP administration causes an oxidative imbalance in the brain areas studied; however, in the presence of simvastatin, some of these alterations in oxidative stress were prevented. © 2016 Wiley Periodicals, Inc.

  1. Anodal Transcranial Direct Current Stimulation Provokes Neuroplasticity in Repetitive Mild Traumatic Brain Injury in Rats

    Directory of Open Access Journals (Sweden)

    Ho Jeong Kim

    2017-01-01

    Full Text Available Repetitive mild traumatic brain injury (rmTBI provokes behavioral and cognitive changes. But the study about electrophysiologic findings and managements of rmTBI is limited. In this study, we investigate the effects of anodal transcranial direct current stimulation (tDCS on rmTBI. Thirty-one Sprague Dawley rats were divided into the following groups: sham, rmTBI, and rmTBI treated by tDCS. Animals received closed head mTBI three consecutive times a day. Anodal tDCS was applied to the left motor cortex. We evaluated the motor-evoked potential (MEP and the somatosensory-evoked potential (SEP. T2-weighted magnetic resonance imaging was performed 12 days after rmTBI. After rmTBI, the latency of MEP was prolonged and the amplitude in the right hind limb was reduced in the rmTBI group. The latency of SEP was delayed and the amplitude was decreased after rmTBI in the rmTBI group. In the tDCS group, the amplitude in both hind limbs was increased after tDCS in comparison with the values before rmTBI. Anodal tDCS after rmTBI seems to be a useful tool for promoting transient motor recovery through increasing the synchronicity of cortical firing, and it induces early recovery of consciousness. It can contribute to management of concussion in humans if further study is performed.

  2. [Risk factors for provoking collisions between cyclists and pedestrians in Spain, 1993-2011].

    Science.gov (United States)

    Martínez Ruiz, Virginia; Jiménez Mejías, Eladio; Amezcua Prieto, Carmen; Olmedo Requena, Rocío; Pulido Manzanero, José; Lardelli Claret, Pablo

    2015-09-01

    To identify and quantify the factors depending on pedestrians, cyclists and the environment associated with the risk of causing a collision between a cyclist and a pedestrian in Spain from 1993 to 2011. retrospective case series. 1228 pedestrian-cyclist pairs involved in the same number of collisions in an urban area, only one of whom committed an infraction. Register of Traffic Accidents with Victims, supported by the Spanish Traffic General Directorate. committing an infraction (yes/no), age, sex, helmet use (cyclist), hour, type of day, year, existence of sidewalks, place of the accident, and priority regulated. logistic regression model to estimate the strength of the association between the pedestrian's responsibility and independent variables. The association with the cyclist's responsibility was assessed by reversing the value of the odds ratios obtained. In both groups of users, the risk of causing a collision was higher in extreme ages. Female cyclists had a slightly higher risk than male cyclists, while the use of a helmet had a protective effect. The risk of the pedestrian causing an accident was higher in the absence of sidewalks. Cyclists more frequently provoked accidents in crosswalks. We recommend the implementation of safety campaigns aimed at pedestrians and cyclists, with special attention paid to the youngest and older people. Interventions for correct road use would also be advisable. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  3. Original article Coffee consumption and propensity to experience aggressive feelings in provoking and frustrating situations

    Directory of Open Access Journals (Sweden)

    Anna Zajenkowska

    2015-07-01

    Full Text Available The present study focused on examining whether coffee intake is related to the intensity of aggressive feelings in reaction to various provoking or frustrating situations, along with consideration of sex and culture. Previous studies focused mainly on the dose of caffeine (not the habit of coffee drinking and aggressive behavior. Many of these studies showed a positive relation between the amount of caffeine consumed and aggression, so it was expected that also habitual coffee consumption would be positively related to propensity for aggressive feelings in situ ations of provocation and frustration. Participants from Greece (n = 299 and Poland (n = 300 declared whether they were coffee drinkers (at least 1 mug of coffee per day and completed the Situational Triggers of Aggressive Responses questionnaire. The results showed that in females, coffee drinkers had higher scores in Sensitivity to Provocation (SP and Frustration (SF than nondrinkers, while no differences between drinkers and nondrinkers appeared in males. Moreover, amongst coffee drinkers, females had higher scores in SP and SF than males, while no sex differences were found in nondrinkers. Furthermore, in Poland coffee drinkers had higher SP scores than nondrinkers. Poles also had higher SP scores than Greeks, but only when coffee drinkers were compared.

  4. Post-injection induced seismicity provoked by superposition of different mechanisms.

    Science.gov (United States)

    De Simone, Silvia; Carrera, Jesus; Vilarrasa, Victor

    2017-04-01

    Induced microseismicity is a controversial issue related to fluid injection into deep geological formations. The occurring of felt earthquakes after stopping injection especially generates concern, because the correlation between injection and seismic activity is unclear. Thus, advancing in its understanding is crucial to minimize its occurrence. Here, we perform numerical simulations of hydraulic stimulation of deep geothermal systems to analyze the mechanisms that may induce or trigger co- and post-injection seismicity. Apart from the direct impact of fluid pressure increase, we acknowledge thermal effects due to cooling and stress redistribution due to fault slip. We analyze the effect of these three processes both separately and superimposed. We find that preferential flow through conductive fractures or fault zones provokes pressure and temperature perturbations that result in not only heterogeneous variation of the stress field, but also highly anisotropic variations of the local stress tensor. Anisotropic variations tend to stabilize some fractures, but destabilize others. Moreover, shear slip causes a significant variation of the stress field that enlarges the range of critical fracture orientations. We find that, given the different response times of mechanical, hydraulic and thermal effects, post-injection seismicity may occur on non-critically oriented faults that were originally stable. During injection, such faults become destabilized by thermal and shear slip stress changes, but remain static by the superposition of pressure forcing. However, they become unstable and fail when the pressure forcing dissipates shortly after injection stops abruptly.

  5. Paternal bisphenol a diet changes prefrontal cortex proteome and provokes behavioral dysfunction in male offspring.

    Science.gov (United States)

    Luo, Guangying; Wei, Ruifen; Wang, Shaolin; Wang, Jundong

    2017-10-01

    Relatively little attention has been given paternal effects on next generation. Given that Bisphenol A (BPA), a ubiquitous compound in maternal diet, may disrupt brain development and behavior, we hypothesized that paternal BPA diet (PBD) could affect offspring development. Prefrontal cortex (PFC), a vital brain region, is involved in emotion and social behavior. To test whether PBD could alter developing PFC, we carried out a proteomics approach for PFC in male juvenile offspring that responded to PBD (50 mg BPA/kg diet). We found that PBD altered the expressions of binding immunoglobulin protein (BIP), CCAAT/-enhancer-binding protein homologous protein (CHOP) and B-cell lymphoma-2 (BCL-2), which could reflect endoplasmic reticulum (ER) stress. In addition, downregulation of myelinogenesis genes and myelin basic protein (MBP) could provoke myelin deficiency. Furthermore, PBD significantly increased anxiety-like behavior and impaired social behavior in male offspring. Taken together, these results revealed the alterations of ER stress and myelin destruction related molecules induced by PBD might be a potential mechanism for the behavior deficits in their male offspring. These findings remind us of the importance of paternal effects in the further environmental exposure research. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Perception of experimental pain is reduced after provoked waking from rapid eye movement sleep.

    Science.gov (United States)

    Daya, Vivek G; Bentley, Alison J

    2010-06-01

    Patients with chronic pain often complain of pain when they wake at night, but the accuracy of their perception of the pain after waking at night is unknown. While cognitive functions are reduced for a short time after waking from sleep, a situation known as sleep inertia, it is unclear how sleep inertia may affect the perception of pain. We investigated the effects of sleep inertia on the perception of experimentally induced pain. Fourteen male volunteers were exposed to a randomized thermal heat stimulus of 43.1 degrees C 'hot' and 46.5 degrees C 'hurting' during provoked waking from Stage 2 sleep, slow wave sleep and rapid eye movement (REM) sleep. Subjects rated their pain on awakening on a Visual Analogue Scale at 30 s after awakening and each minute thereafter for 5 min. We found no change in pain perception over the 5-min period irrespective of temperature used or sleep stage. However, perceived pain when awoken abruptly from REM sleep was significantly lower than the awake score for both the hot (P = 0.0069) and hurting (P = 0.0025) temperatures. Pain perception when woken from Stage 2 sleep or slow wave sleep was not significantly different from perception when awake. Our findings indicate that sleep inertia reduces pain perception when awoken abruptly from REM. This suggests that patients who wake up in pain either perceive accurately the pain they are experiencing, or at worst underestimate the level of pain if woken from REM sleep.

  7. Home-Schooled Students And Their Teachers: Provoking Curriculum Together Through Child-Driven Learning

    Directory of Open Access Journals (Sweden)

    Karen E. EFFORD

    2017-12-01

    Full Text Available Child-centered and child-driven learning can provoke the creation of curriculum that is responsive to students’ particular learning needs, is engaging and meaningful, and promotes learner agency. Homeschool settings provide opportunities for parent/educators cognizant of child-centered and child-driven curriculum to meet students’ interests, readiness, growth, and educational drive with responses tailored for each unique situation. This learning space can allow for the relationship between the parent/educator and the student to continually revisit and revitalize learning, expanding on shared experience and potentially spanning the developmental years of the student. The lines between educator and student become blurred as the educator is directed by the unique interests and educational needs of each student. Research into the field of homeschooling curriculum can inspire discussion and innovation in more traditional educational settings. In this paper presentation, the authors will discuss the literature on child-centered and child-driven learning. Next, stories from real homeschools illustrating the co-creation of child- centered curriculum by both the educator/parent and student will be shared. Finally, the presenters will kindle a lively conversation with all participants about the role of students and teachers in curriculum creation, student-centered and student-driven learning in homeschools and in public schools, and imagining the possibilities of both contexts.

  8. The Dynamics of the Electric Field Distribution in the Surface of Insulating Film Irradiated by Air Ions

    Directory of Open Access Journals (Sweden)

    Julionas KALADE

    2016-05-01

    Full Text Available When deposited on a surface, electric charge usually accumulates near the tips of surface irregularities, from where it can be transferred to nearby objects due to ionization of ambient air. The amount of transferred charge, the rate of charge transfer, the size of the charged spot (e.g., on the surface of an insulator and its tendency to spread will depend on properties of air during electric discharge, on the magnitude of charge accumulated at the tip of an object, on possibilities for replenishing that charge, on the time spent for charge transfer from the tip onto the insulating layer, on properties of the insulating layer, etc. Those properties are discussed in this work by comparing the results of measurements and theoretical analysis.

  9. Line shapes and time dynamics of the Förster resonances between two Rydberg atoms in a time-varying electric field

    KAUST Repository

    Yakshina, E. A.

    2016-10-21

    The observation of the Stark-tuned Förster resonances between Rydberg atoms excited by narrowband cw laser radiation requires usage of a Stark-switching technique in order to excite the atoms first in a fixed electric field and then to induce the interactions in a varied electric field, which is scanned across the Förster resonance. In our experiments with a few cold Rb Rydberg atoms, we have found that the transients at the edges of the electric pulses strongly affect the line shapes of the Förster resonances, since the population transfer at the resonances occurs on a time scale of ∼100 ns, which is comparable with the duration of the transients. For example, a short-term ringing at a certain frequency causes additional radio-frequency-assisted Förster resonances, while nonsharp edges lead to asymmetry. The intentional application of the radio-frequency field induces transitions between collective states, whose line shape depends on the interaction strengths and time. Spatial averaging over the atom positions in a single interaction volume yields a cusped line shape of the Förster resonance. We present a detailed experimental and theoretical analysis of the line shape and time dynamics of the Stark-tuned Förster resonances Rb(nP3/2)+Rb(nP3/2)→Rb(nS1/2)+Rb([n+1]S1/2) for two Rb Rydberg atoms interacting in a time-varying electric field.

  10. High speed, high temperature electrical characterization of phase change materials: metastable phases, crystallization dynamics, and resistance drift.

    Science.gov (United States)

    Dirisaglik, Faruk; Bakan, Gokhan; Jurado, Zoila; Muneer, Sadid; Akbulut, Mustafa; Rarey, Jonathan; Sullivan, Lindsay; Wennberg, Maren; King, Adrienne; Zhang, Lingyi; Nowak, Rebecca; Lam, Chung; Silva, Helena; Gokirmak, Ali

    2015-10-28

    During the fast switching in Ge2Sb2Te5 phase change memory devices, both the amorphous and fcc crystalline phases remain metastable beyond the fcc and hexagonal transition temperatures respectively. In this work, the metastable electrical properties together with crystallization times and resistance drift behaviour of GST are studied using a high-speed, device-level characterization technique in the temperature range of 300 K to 675 K.

  11. Co-evolution of waste and electricity regimes: Multi-regime dynamics in the Netherlands (1969-2003)

    Energy Technology Data Exchange (ETDEWEB)

    Raven, Rob [Eindhoven University of Technology, Department of Technology Management, Section of Technology and Sustainability Studies, Room IPO 2.10, P.O. Box 513, 5600 MB Eindhoven (Netherlands)]. E-mail: r.p.j.m.raven@tm.tue.nl

    2007-04-15

    This article explores how the relation between waste and electricity regimes changed in the Netherlands in a long-term perspective. The concept of socio-technical regime is used to investigate institutional, technological and social (network) changes. The conclusion is that the relationship changed from two regimes being separated into a much more symbiotic and integrated relationship through a multi-level and co-evolutionary process. The concept of 'biomass' has become a binding element in the relationship.

  12. Quantum Dynamics in Atomic-Fountain Experiments for Measuring the Electric Dipole Moment of the Electron with Improved Sensitivity

    Directory of Open Access Journals (Sweden)

    B. J. Wundt

    2012-11-01

    Full Text Available An improved measurement of the electron electric dipole moment (EDM appears feasible using ground-state alkali atoms in an atomic fountain in which a strong electric field, which couples to a conceivable EDM, is applied perpendicular to the fountain axis. In a practical fountain, the ratio of the atomic tensor Stark shift to the Zeeman shift is a factor μ∼100. We expand the complete time-evolution operator in inverse powers of this ratio; complete results are presented for atoms of total spin F=3, 4, and 5. For a specific set of entangled hyperfine sublevels (coherent states, potential systematic errors enter only as even powers of 1/μ, making the expansion rapidly convergent. The remaining EDM-mimicking effects are further suppressed in a proposed double-differential setup, where the final state is interrogated in a differential laser configuration, and the direction of the strong electric field also is inverted. Estimates of the signal available at existing accelerator facilities indicate that the proposed apparatus offers the potential for a drastic improvement in EDM limits over existing measurements, and for constraining the parameter space of supersymmetric (SUSY extensions of the Standard Model.

  13. Impact of Silicon Carbide Devices on the Dynamic Performance of Permanent Magnet Synchronous Motor Drive Systems for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Xiaofeng Ding

    2017-03-01

    Full Text Available This paper investigates the impact of silicon carbide (SiC metal oxide semiconductor field effect transistors (MOSFETs on the dynamic performance of permanent magnet synchronous motor (PMSM drive systems. The characteristics of SiC MOSFETs are evaluated experimentally taking into account temperature variations. Then the switching characteristics are firstly introduced into the transfer function of a SiC-inverter fed PMSM drive system. The main contribution of this paper is the investigation of the dynamic control performance features such as the fast response, the stability and the robustness of the drive system considering the characteristics of SiC MOSFETs. All the results of the SiC-drive system are compared to the silicon-(Si insulated gate bipolar transistors (IGBTs drive system counterpart, and the SiC-drive system manifests a higher dynamic performance than the Si-drive system. The analytical results have been effectively validated by experiments on a test bench.

  14. Exploration of the Growing Trend of Electric Vehicles in Beijing with System Dynamics method and Vensim model

    NARCIS (Netherlands)

    Zhang, C.; Qin, C.

    2014-01-01

    This research is conducted to explore the growing trend of private vehicles in Beijing, China, in the coming 25 years using the system dynamics (SD) method. The vensim software is used to build the SD model and do simulations. First, the paper introduces the background of the private vehicles in

  15. Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

    Science.gov (United States)

    Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

    2015-11-01

    Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology. Copyright © 2015 Elsevier Inc. All rights reserved.

  16. Daily associations between partner responses and sexual and relationship satisfaction in couples coping with provoked vestibulodynia.

    Science.gov (United States)

    Rosen, Natalie O; Muise, Amy; Bergeron, Sophie; Delisle, Isabelle; Baxter, Mary Lou

    2015-04-01

    Women with provoked vestibulodynia (PVD) experience a recurrent vulvo-vaginal pain triggered primarily during sexual intercourse. Although affected couples report adverse effects on their sexual and global romantic relationships, few studies have examined interpersonal factors that may influence their sexual and relationship satisfaction. Cross-sectional studies have shown that greater partner solicitous and negative responses and lower facilitative responses are associated with poorer sexual and relationship satisfaction in women with PVD. The aim of this study was to investigate the within-person associations between partner responses to painful intercourse and the sexual and relationship satisfaction of affected couples. In a dyadic daily experience study, 69 women (M(age) = 28.46, SD = 6.66) diagnosed with PVD and their cohabitating male partners (M(age) = 30.29, SD = 8.13) reported on male partner responses, as well as sexual and relationship satisfaction on sexual intercourse days (M = 6.81; SD = 5.40) over 8 weeks. Dependent measures were the (i) Kansas Marital Satisfaction Scale and (ii) Global Measure of Sexual Satisfaction Scale. On sexual intercourse days when women perceived more facilitative partner responses than usual and on days when they perceived lower negative partner responses than usual, they reported higher sexual and relationship satisfaction. On sexual intercourse days when men reported more solicitous responses than usual, both they and their female partners reported lower sexual satisfaction. Interventions aimed at improving the day-to-day sexual and relationship satisfaction of couples with PVD should target increasing facilitative and decreasing negative and solicitous partner responses. © 2015 International Society for Sexual Medicine.

  17. Short pain-provoked head-up tilt test for the confirmation of vasovagal syncope.

    Science.gov (United States)

    Adamec, Ivan; Mišmaš, Antonija; Zaper, Dinka; Junaković, Anamari; Hajnšek, Sanja; Habek, Mario

    2013-06-01

    We investigated a short pain-provoked head-up tilt (PP-HUT) and the Calgary Syncope Symptom Score in a group of patients with clinically diagnosed vasovagal syncope and group of neurological patients without transient loss of consciousness. We included 127 consecutive patients who were investigated in our laboratory. The group 1 included 56 patients who after appropriate investigations were diagnosed with vasovagal syncope. The group 2 included 70 neurological patients without transient loss of consciousness. The subjects were tilted to 70° for a maximum period of 10 min or until symptoms occurred. If there were no symptoms after initial 10 min, a painful stimulus with the insertion of 0.7 mm needle into the dorsum of hand subcutaneously for 30 s was performed with the patient in the tilted for further 5 min. Calgary Syncope Symptom Score was calculated for all patients. In the group 1, significantly higher number of patients had positive results on PP-HUT (36 vs. 6 patients, respectively; p syndrome (3 vs. 1 patient, respectively; p = 0.32) between groups. PP-HUT had sensitivity of 65.9 % (95 % CI 0.49-0.79) and specificity of 89.7 % (95 % CI 0.75-0.97). The CSSS had sensitivity of 58.5 % (95 % CI 0.42-0.73) and specificity of 46.1 % (95 % CI 0.30-0.63). PP-HUT has a higher diagnostic rate than the CSSS and provides a rapid alternative to conventional methods.

  18. GCH1-polymorphism and pain sensitivity among women with provoked vestibulodynia

    Directory of Open Access Journals (Sweden)

    Heddini Ulrika

    2012-09-01

    Full Text Available Abstract Background Provoked vestibulodynia (PVD is a pain disorder localized in the vestibular mucosa. It is the most common cause of dyspareunia among young women and it is associated with general pain hypersensitivity and other chronic pain conditions. Polymorphism in the guanosine triphosphate cyclohydrolase (GCH1 gene has been found to influence general pain sensitivity and the risk of developing a longstanding pain condition. The aim of this study was to investigate GCH1-polymorphism in women with PVD and healthy controls, in correlation to pain sensitivity. Results We found no correlation between the previously defined pain-protective GCH1-SNP combination and the diagnosis of PVD. Nor any correlation with pain sensitivity measured as pressure pain thresholds on the arm, leg and in the vestibule, coital pain scored on a visual analog scale and prevalence of other bodily pain conditions among women with PVD (n = 98 and healthy controls (n = 102. However, among patients with current treatment (n = 36, there was a significant interaction effect of GCH1-gene polymorphism and hormonal contraceptive (HC therapy on coital pain (p = 0.04 as well as on pressure pain thresholds on the arm (p = 0.04. PVD patients carrying the specified SNP combination and using HCs had higher pain sensitivity compared to non-carriers. In non-HC-users, carriers had lower pain sensitivity. Conclusions The results of this study gave no support to the hypothesis that polymorphism in the GCH1-gene contributes to the etiology of PVD. However, among patients currently receiving treatment an interaction effect of the defined SNP combination and use of hormonal contraceptives on pain sensitivity was found. This finding offers a possible explanation to the clinically known fact that some PVD patients improve after cessation of hormonal contraceptives, indicating that PVD patients carrying the defined SNP combination of GCH1 would benefit from this

  19. The recurrent pain and sexual sequelae of provoked vestibulodynia: a perpetuating cycle.

    Science.gov (United States)

    Basson, Rosemary

    2012-08-01

    Optimal management of provoked vestibulodynia (PVD), thought to be the most common form of chronic dyspareunia, is unclear. To integrate recent brain data on chronic pain circuitry with stress-induced neuroendocrine mechanisms in the skin and the stress burden (allostatic load) of women with PVD; to also clarify the typical chronicity and negative sexual sequelae associated with PVD; and then review modulation of pain circuitry by cognitive therapy and mindfulness practice and apply to PVD management. Methods.  Review of scientific publications in the areas of sexual medicine, pain, brain imaging, gynecology, stress response, mindfulness, and cognitive behavioral therapy (CBT). (i) A model of PVD to reflect its etiology, typical chronicity, and the detrimental effects on sexual function; (ii) Interventions of sexual rehabilitation based on principles underlying changes associated with CBT and mindfulness practice. A model emerges which reflects how stress-induced changes of pain amplification (central sensitization), characteristic of chronic pain conditions, may impair sexual response in addition to sexual dysfunction that arises from conscious pain avoidance and/or fear-related inattention to sexual cues. Stress from low self-acceptance may be a major component of the allostatic load present in women with PVD, only to be exacerbated by the sexual dysfunction precipitated by the pain of intercourse. Mindfulness-based CBT appears promising to target both the pain and sexual suffering from PVD. New findings on brain activity associated with recurrent clinical pain, functional brain changes associated with CBT and mindfulness, plus new data on stress systems within the skin along with data on increased stress load in women with PVD, support the use of mindfulness-based CBT for the recurrent pain and sexual suffering from PVD. © 2012 International Society for Sexual Medicine.

  20. Performance and microbial community dynamics of electricity-assisted sequencing batch reactor (SBR) for treatment of saline petrochemical wastewater.

    Science.gov (United States)

    Liu, Jiaxin; Shi, Shengnan; Ji, Xiangyu; Jiang, Bei; Xue, Lanlan; Li, Meidi; Tan, Liang

    2017-07-01

    High-salinity wastewater is often difficult to treat by common biological technologies due to salinity stress on the bacterial community. Electricity-assisted anaerobic technologies have significantly enhanced the treatment performance by alleviating the impact of salinity stress on the bacterial community, but electricity-assisted aerobic technologies have less been reported. Herein, a novel bio-electrochemistry system has been designed and operated in which a pair of stainless iron mesh-graphite plate electrodes were installed into a sequencing batch reactor (SBR, designated as S1) to strengthen the performance of saline petrochemical wastewater under aerobic conditions. The removal efficiency of phenol and chemical oxygen demand (COD) in S1 were 94.1 and 91.2%, respectively, on day 45, which was clearly higher than the removal efficiency of a single SBR (S2) and an electrochemical reactor (S3), indicating that a coupling effect existed between the electrochemical process and biodegradation. A certain amount of salinity (≤8000 mg/L) could enhance the treatment performance in S1 but weaken that in S2. Illumina sequencing revealed that microbial communities in S1 on days 45 and 91 were richer and more diverse than in S2, which suggests that electrical stimulation could enhance the diversity and richness of the microbial community, and reduce the negative effect of salinity on the microorganisms and enrich some salt-adapted microorganisms, thus improve the ability of S1 to respond to salinity stress. This novel bio-electrochemistry system was shown to be an alternative technology for the high saline petrochemical wastewater.

  1. Costs and Operating Dynamics of Integrating Distributed Energy Resources in Commercial and Industrial Buildings with Electric Vehicle Charging

    Science.gov (United States)

    Flores, Robert Joseph

    Growing concerns over greenhouse gas and pollutant emissions have increased the pressure to shift energy conversion paradigms from current forms to more sustainable methods, such as through the use of distributed energy resources (DER) at industrial and commercial buildings. This dissertation is concerned with the optimal design and dispatch of a DER system installed at an industrial or commercial building. An optimization model that accurately captures typical utility costs and the physical constraints of a combined cooling, heating, and power (CCHP) system is designed to size and operate a DER system at a building. The optimization model is then used with cooperative game theory to evaluate the financial performance of a CCHP investment. The CCHP model is then modified to include energy storage, solar powered generators, alternative fuel sources, carbon emission limits, and building interactions with public and fleet PEVs. Then, a separate plugin electric vehicle (PEV) refueling model is developed to determine the cost to operate a public Level 3 fast charging station. The CCHP design and dispatch results show the size of the building load and consistency of the thermal loads are critical to positive financial performance. While using the CCHP system to produce cooling can provide savings, heat production drives positive financial performance. When designing the DER system to reduce carbon emissions, the use of renewable fuels can allow for a gas turbine system with heat recovery to reduce carbon emissions for a large university by 67%. Further reductions require large photovoltaic installations coupled with energy storage or the ability to export electricity back to the grid if costs are to remain relatively low. When considering Level 3 fast charging equipment, demand charges at low PEV travel levels are sufficiently high to discourage adoption. Integration of the equipment can reduce demand charge costs only if the building maximum demand does not coincide

  2. Multilevel measurement of the electric field underneath a thundercloud: 2. Dynamical evolution of a ground space charge layer

    Science.gov (United States)

    Soula, Serge; Chauzy, Serge

    1991-12-01

    In August 1989 the electric field was measured below a thunderstorm at Kennedy Space Center for more than 1 hour at several levels up to 800 m. No substantial precipitation reached the ground at the experimental site until after this data collection period, which included the thunderstorm approach and the triggering of four lightning flashes. The sensors at altitude were suspended from a tethered balloon and that at the surface was a standard field mill. The maximum value detected was 65 kV/m at 603 m while at the same time the steady surface field did not exceed 5 kV/m. Applying Gauss's law to the electric field data, we have calculated average charge densities within the layers formed by the levels where the sensors were located. Corona ions produced at the surface were detected up to the upper layer between 436 m and 603 m, and the densities calculated reached values close to 1 nC m-3 within each layer. The current densities were also evaluated at the sensor levels; the one calculated at 436 m ranges about 1.4 nA m-2 which means that a large proportion of corona ions were carried up to several hundreds of meters above ground.

  3. The Local Structure of Globalization. The Network Dynamics of Foreign Direct Investments in the International Electricity Industry

    Science.gov (United States)

    Koskinen, Johan; Lomi, Alessandro

    2013-05-01

    We study the evolution of the network of foreign direct investment (FDI) in the international electricity industry during the period 1994-2003. We assume that the ties in the network of investment relations between countries are created and deleted in continuous time, according to a conditional Gibbs distribution. This assumption allows us to take simultaneously into account the aggregate predictions of the well-established gravity model of international trade as well as local dependencies between network ties connecting the countries in our sample. According to the modified version of the gravity model that we specify, the probability of observing an investment tie between two countries depends on the mass of the economies involved, their physical distance, and the tendency of the network to self-organize into local configurations of network ties. While the limiting distribution of the data generating process is an exponential random graph model, we do not assume the system to be in equilibrium. We find evidence of the effects of the standard gravity model of international trade on evolution of the global FDI network. However, we also provide evidence of significant dyadic and extra-dyadic dependencies between investment ties that are typically ignored in available research. We show that local dependencies between national electricity industries are sufficient for explaining global properties of the network of foreign direct investments. We also show, however, that network dependencies vary significantly over time giving rise to a time-heterogeneous localized process of network evolution.

  4. Electrically tunable transport and high-frequency dynamics in antiferromagnetic S r3I r2O7

    Science.gov (United States)

    Seinige, Heidi; Williamson, Morgan; Shen, Shida; Wang, Cheng; Cao, Gang; Zhou, Jianshi; Goodenough, John B.; Tsoi, Maxim

    2016-12-01

    We report dc and high-frequency transport properties of antiferromagnetic S r3I r2O7 . Temperature-dependent resistivity measurements show that the activation energy of this material can be tuned by an applied dc electrical bias. The latter allows for continuous variations in the sample resistivity of as much as 50% followed by a reversible resistive switching at higher biases. Such a switching is of high interest for antiferromagnetic applications in high-speed memory devices. Interestingly, we found the switching behavior to be strongly affected by a high-frequency (microwave) current applied to the sample. The microwaves at 3-7 GHz suppress the dc switching and produce resonancelike features that we tentatively associated with the dissipationless magnonics recently predicted to occur in antiferromagnetic insulators subject to ac electric fields. We have characterized the effects of microwave irradiation on electronic transport in S r3I r2O7 as a function of microwave frequency and power, strength and direction of external magnetic field, strength and polarity of applied dc bias, and temperature. Our observations support the potential of antiferromagnetic materials for high-speed/high-frequency spintronic applications.

  5. Systematic characterization of structural, dynamical and electrical properties of dust devils and implications for dust lifting processes

    Science.gov (United States)

    Franzese, Gabriele; Esposito, Francesca; Lorenz, Ralph D.; Popa, Ciprian; Silvestro, Simone; Deniskina, Natalia; Cozzolino, Fabio

    2017-04-01

    Dust devils are convective vortices able to lift sand and dust grains from the soil surface, even in conditions of low wind speed environment. They have been observed not only on Earth but also on other planets of the solar system; in particular, they are largely studied on Mars. Indeed, the contribution of the dust devils to the Martian climate is a highly debated question. In order to investigate this topic, it is important to understand the nature of the dust lifting mechanism by the vortex and characterize the induced electric field. As part of the development process of DREAMS, the meteorological station on board the Schiapparelli lander of the ExoMars 2016 mission, and of the Dust complex package of the ExoMars 2020 mission, we performed various field campaigns in the Sahara desert (Tafilalt region, Morocco). We deployed a fully equipped meteorological station and, during the 2014 summer, we observed three months of dust devils activity, collecting almost six hundreds events. For each dust devil, we monitored the horizontal wind speed and direction, the vertical wind speed, the pressure drop due to the vortex core, the temperature, the induced electric field and the concentration of dust lifted. This data set is unique in literature and represents up to now the most comprehensive one available for the dusty convective vortices. Here we will present the analysis of the Moroccan data with particular emphasis on the study of the atmospheric electric field variations due to the passage of the vortices. The distribution of the vortex parameters (wind speed and direction, pressure, E-field and dust lifted) are showed and compared, when possible, to the ones observed by the Martian surveys. The connection between the E-field and the other parameters will be presented. In the terrestrial environment, the development of the convective vortices is restricted by the presence of the vegetation and of the urban areas, hence dust devils can impact the climate only on local

  6. Evaluation of dynamic security in electric power systems using coherency-based dynamic equivalents; Avaliacao da seguranca dinamica de sistemas de potencia utilizando equivalentes dinamicos baseados em coerencia

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Eduardo J.S. Pires de [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Eletrica; Macedo, Nilo J.P. de [FURNAS, Rio de Janeiro, RJ (Brazil). Div. de Estudos Especiais da Operacao

    1997-12-31

    The interconnected power systems are now more dependent of controls in normal operation as well as in emergency conditions. There is a growing need to analyze a large number of actual conditions that may occur, which require the use of efficient tools. The aim of this paper is to present the results of the application of the coherency-based dynamic equivalents calculation methodology to determine drastic reductions of large scale power systems for studies with the hybrid simulator of FURNAS. (author) 5 refs., 7 figs.; e-mail: pires at ele.puc-rio.br; nilojpm at furnas.com.br

  7. Safety assessment for electricity generation failure accident of gas cooled nuclear power plant using system dynamics (SD) method

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2013-04-15

    The power production failure happens in the loss of coolant of the nuclear power plants (NPPs). The air ingress is a serious accident in gas cooled NPPs. The quantification of the study performed by the system dynamics (SD) method which is processed by the feedback algorithms. The Vensim software package is used for the simulation, which is performed by the Monte-Carlo method. Two kinds of considerations as the economic and safety properties are important in NPPs. The result shows the stability of the operation when the power can be decided. The maximum value of risk is the 11.77 in 43rd and the minimum value is 0.0 in several years. So, the success of the circulation of coolant is simulated by the dynamical values. (orig.)

  8. The Dynamic Earth: Recycling Naturally!

    Science.gov (United States)

    Goldston, M. Jenice; Allison, Elizabeth; Fowler, Lisa; Glaze, Amanda

    2013-01-01

    This article begins with a thought-provoking question: What do you think of when you hear the term "recycle?" Many think about paper, glass, aluminum cans, landfills, and reducing waste by reusing some of these materials. How many of us ever consider the way the systems of Earth dynamically recycle its materials? In the following…

  9. Improvement of the Koradi parallel algorithm for molecular dynamics and application to the economic organization and optimization of recycling costs of waste electrical and electronic equipment

    Science.gov (United States)

    Cabria, I.; Queiruga, D.

    2005-09-01

    A parallel algorithm for molecular dynamics, MD, the Koradi point-centered decomposition algorithm, especially designed for inhomogeneous systems, is improved and applied to the organization and optimization of recycling costs of Waste Electrical and Electronic Equipment, WEEE, and also to systems of atoms. This organization requires the numbers and locations of storage centers and recycling plants of the WEEE that minimize the recycling cost. The Koradi algorithm finds these optimal numbers and locations, dealing very fast with large numbers of data, in contrast with other methods. The changes of the original algorithm (different ways of generating the initial centers and especially the requirement of location convergence) improve its performance for this economic problem and also for MD simulations.

  10. Comparisons of Energy Management Methods for a Parallel Plug-In Hybrid Electric Vehicle between the Convex Optimization and Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Renxin Xiao

    2018-01-01

    Full Text Available This paper proposes a comparison study of energy management methods for a parallel plug-in hybrid electric vehicle (PHEV. Based on detailed analysis of the vehicle driveline, quadratic convex functions are presented to describe the nonlinear relationship between engine fuel-rate and battery charging power at different vehicle speed and driveline power demand. The engine-on power threshold is estimated by the simulated annealing (SA algorithm, and the battery power command is achieved by convex optimization with target of improving fuel economy, compared with the dynamic programming (DP based method and the charging depleting–charging sustaining (CD/CS method. In addition, the proposed control methods are discussed at different initial battery state of charge (SOC values to extend the application. Simulation results validate that the proposed strategy based on convex optimization can save the fuel consumption and reduce the computation burden obviously.

  11. Muscle stimulation waveform timing patterns for upper and lower leg muscle groups to increase muscular endurance in functional electrical stimulation pedaling using a forward dynamic model.

    Science.gov (United States)

    Hakansson, Nils A; Hull, M L

    2009-09-01

    Functional electrical stimulation (FES) of pedaling provides a means by which individuals with spinal cord injury can obtain cardiorespiratory exercise. However, the early onset of muscle fatigue is a limiting factor in the cardiorespiratory exercise obtained while pedaling an FES ergometer. One objective of this study was to determine muscle excitation timing patterns to increase muscle endurance in FES pedaling for three upper leg muscle groups and to compare these timing patterns to those used in a commercially available FES ergometer. The second objective was to determine excitation timing patterns for a lower leg muscle group in conjunction with the three upper leg muscle groups. The final objective was to determine the mechanical energy contributions of each of the muscle groups to drive the crank. To fulfill these objectives, we developed a forward dynamic simulation of FES pedaling to determine electrical stimulation on and off times that minimize the muscle stress-time integral of the stimulated muscles. The computed electrical stimulation on and off times differed from those utilized by a commercially available FES ergometer and resulted in 17% and 11% decrease in the muscle stress-time integral for the three upper leg muscle groups and four upper and lower leg muscle groups, respectively. Also, the duration of muscle activation by the hamstrings increased by 5% over a crank cycle for the computed stimulation on and off times, and the mechanical energy generated by the hamstrings increased by 20%. The lower leg muscle group did not generate sufficient mechanical energy to reduce the energy contributions of the upper leg muscle groups. The computed stimulation on and off times could prolong FES pedaling, and thereby provide improved cardiorespiratory and muscle training outcomes for individuals with spinal cord injury. Including the lower leg muscle group in FES pedaling could increase cardiorespiratory demand while not affecting the endurance of the

  12. Long-term consequences of selected competitive strategies during deregulation of the United States electric utility industry: System dynamics modeling and simulation

    Science.gov (United States)

    Khalil, Yehia Fahim

    Currently, U.S. investor-owned utilities (IOUs) are facing major reforms in their business environment similar to the airlines, telecommunications, banking, and insurance industries. As a result, IOUs are gearing up for fierce price competition in the power generation sector, and are vying for electricity customers outside their franchised service territories. Energy experts predict that some IOUs may suffer fatal financial setbacks (especially those with nuclear plants), while others may thrive under competition. Both federal and state energy regulators anticipate that it may take from five to ten years to complete the transition of America's electric utility industry from a regulated monopoly to a market-driven business. During this transition, utility executives are pursuing aggressive business strategies to confront the upcoming price wars. The most compelling strategies focus on cutting operation and maintenance (O&M) costs of power production, downsizing the work force, and signing bilateral energy agreements with large price-sensitive customers to retain their business. This research assesses the impact of the three pivotal strategies on financial performance of utilities during transition to open market competition. A system-dynamics-based management flight simulator has been developed to predict the dynamic performance of a hypothetical IOU organization preparing for market competition. The simulation results show that while the three business strategies lead to short-lived gains, they also produce unanticipated long-term consequences that adversely impact the organization's operating revenues. Generally, the designed flight simulator serves as a learning laboratory which allows management to test new strategies before implementation.

  13. Global Optimal Energy Management Strategy Research for a Plug-In Series-Parallel Hybrid Electric Bus by Using Dynamic Programming

    Directory of Open Access Journals (Sweden)

    Hongwen He

    2013-01-01

    Full Text Available Energy management strategy influences the power performance and fuel economy of plug-in hybrid electric vehicles greatly. To explore the fuel-saving potential of a plug-in hybrid electric bus (PHEB, this paper searched the global optimal energy management strategy using dynamic programming (DP algorithm. Firstly, the simplified backward model of the PHEB was built which is necessary for DP algorithm. Then the torque and speed of engine and the torque of motor were selected as the control variables, and the battery state of charge (SOC was selected as the state variables. The DP solution procedure was listed, and the way was presented to find all possible control variables at every state of each stage in detail. Finally, the appropriate SOC increment is determined after quantizing the state variables, and then the optimal control of long driving distance of a specific driving cycle is replaced with the optimal control of one driving cycle, which reduces the computational time significantly and keeps the precision at the same time. The simulation results show that the fuel economy of the PEHB with the optimal energy management strategy is improved by 53.7% compared with that of the conventional bus, which can be a benchmark for the assessment of other control strategies.

  14. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  15. Surface electromyography of myopotential oversensing provoked by simultaneous straining and leftward twisting in a patient with an implantable cardioverter defibrillator.

    Science.gov (United States)

    Ajiro, Yoichi; Shiga, Tsuyoshi; Shoda, Morio; Hagiwara, Nobuhisa

    2017-03-01

    An important step in diagnosing myopotential oversensing is to confirm its reproducibility using specific provocation maneuvers. Although most maneuvers involve the co-contraction of many muscles, no attempt has been made to assess relevant muscle activities by electromyography. We describe a case with an implantable cardioverter defibrillator (ICD) whose myopotential oversensing was provoked by simultaneous straining and leftward twisting. Simultaneous recordings from real-time ICD telemetry and myopotentials of the rectus abdominis, oblique abdominis, and diaphragm on electromyography during the provocation maneuvers were conducted. It was shown that all three muscles contracted simultaneously during the provocation maneuvers; the diaphragm activity was the main source of noise oversensing, and the twist itself caused oversensing possibly due to the change in the position of the lead. In conclusion, the electromyographic assessment of relevant muscle activities may be useful in assessing each muscle's role and its contribution to myopotential oversensing, especially in a patient whose myopotential oversensing requires complex maneuvers to be provoked.

  16. Seasonal dynamics of electrical impedance parameters in shoots and leaves related to rooting ability of olive (Olea europea) cuttings.

    Science.gov (United States)

    Mancuso, Stefano

    1999-02-01

    Electrical impedance parameters were measured in shoots and leaves of Olea europaea L. for 18 months to determine seasonal variations in intracellular and extracellular resistances and in the state of membranes; these factors were related to rooting ability. Double- and single-DCE (ZARC) models were used as equivalent circuits for shoots and leaves, respectively. Seasonal variations were observed in all of the impedance parameters measured. Intracellular resistance of the shoots increased during the winter resting period, whereas intracellular resistance of the leaves decreased. Relaxation times for both leaves and shoots decreased during the winter. Close relationships were found between rooting ability and intracellular and extracellular resistances and relaxation times of shoots and leaves.

  17. Referred pain patterns provoked on intra-pelvic structures among women with and without chronic pelvic pain : a descriptive study

    OpenAIRE

    Torstensson, Thomas; Butler, Stephen; Lindgren, Anne; Peterson, Magnus; Eriksson, Margaretha; Kristiansson, Per

    2015-01-01

    OBJECTIVES: To describe referred pain patterns provoked from intra-pelvic structures in women with chronic pelvic pain (CPP) persisting after childbirth with the purpose to improve diagnostics and give implications for treatment. MATERIALS AND METHODS: In this descriptive and comparative study 36 parous women with CPP were recruited from a physiotherapy department waiting list and by advertisements in newspapers. A control group of 29 parous women without CPP was consecutively assessed for el...

  18. Carnitine Deficiency and Oxidative Stress Provoke Cardiotoxicity in an Ifosfamide-Induced Fanconi Syndrome Rat Model

    Directory of Open Access Journals (Sweden)

    Mohamed M. Sayed-Ahmed

    2010-01-01

    Full Text Available In addition to hemorrhagic cystitis, Fanconi Syndrome is a serious clinical side effect during ifosfamide (IFO therapy. Fanconi syndrome is a generalized dysfunction of the proximal tubule which is characterized by excessive urinary excretion of glucose, phosphate, bicarbonate, amino acids and other solutes excreted by this segment of the nephron including L-carnitine. Carnitine is essential cofactor for β-oxidation of long-chain fatty acids in the myocardium. IFO therapy is associated with increased urinary carnitine excretion with subsequent secondary deficiency of the molecule. Cardiac abnormalities in IFO-treated cancer patients were reported as isolated clinical cases. This study examined whether carnitine deficiency and oxidative stress, secondary to Fanconi Syndrome, provoke IFO-induced cardiomyopathy as well as exploring if carnitine supplementation using Propionyl-L-carnitine (PLC could offer protection against this toxicity. In the current study, an animal model of carnitine deficiency was developed in rats by D-carnitine-mildronate treatment Adult male Wistar albino rats were assigned to one of six treatment groups: the first three groups were injected intraperitoneally with normal saline, D-carnitine (DC, 250 mg/kg/day combined with mildronate (MD, 200 mg/kg/day and PLC (250 mg/kg/day, respectively, for 10 successive days. The 4th, 5th and 6th groups were injected with the same doses of normal saline, DC-MD and PLC, respectively for 5 successive days before and 5 days concomitant with IFO (50 mg/kg/day. IFO significantly increased serum creatinine, blood urea nitrogen (BUN, urinary carnitine excretion and clearance, creatine phosphokinase isoenzyme (CK-MB, lactate dehydrogenase (LDH, intramitochondrial acetyl-CoA/CoA-SH and thiobarbituric acid reactive substances (TBARS in cardiac tissues and significantly decreased adenosine triphosphate (ATP and total carnitine and reduced glutathione (GSH content in cardiac tissues. In carnitine

  19. Migration Processes Provoked yy the Break-Up of Yugoslavia and the Agression against Croatia

    Directory of Open Access Journals (Sweden)

    Mirjana Domini

    1999-10-01

    Full Text Available The paper deals with forced migration caused by Serb aggression in areas of Croatia and the neighbouring countries. The first part presents the relevant facts relating to Croatia and important for an understanding of the migration flows (some demographic data as well as the basic guidelines of migration policy, legal regulations and most important problems connected with expellees, refugees and displaced persons. The main elements of contemporary migration movements in Croatia are indicated – migration based on economic causes (traditional migration, migration provoked by crisis and war destruction in former Yugoslavia and migration flows that are difficult to register (mainly clandestine crossings of the border of the Republic of Croatia and the irregular labour market. The author states that the expellee, refugee and displaced persons crisis (with psychological and material repercussions began in 1991 and reached a climax in 1992 when Croatia became one of the most pronounced refugee countries in the world, with refugees accounting for about 15% of its population. As the war crisis shifted, the areas from which intense forced migration to and from Croatia resulted also shifted as did the mechanisms for regulating these forced migrations (dual citizenship, transit visas, accords with "third countries" for accepting refugees and expellees, ways of resolving and caring for the refugee-expellee populations in the Republic of Croatia. The author concludes that even after seven years from the start of the aggression against Croatia, this humanitarian crisis among expellees, refugees and displaced persons has not yet finished, as testified by the new military conflict in Kosovo and by many open questions in regard to the future organisation of states in this crisis area as well as the creation of mechanisms for monitoring potential conflicts. A fundamental idea is expressed throughout the paper – i.e. the notion that now it is maybe more

  20. Frequency Dependent Non- Thermal Effects of Oscillating Electric Fields in the Microwave Region on the Properties of a Solvated Lysozyme System: A Molecular Dynamics Study.

    Directory of Open Access Journals (Sweden)

    Stelios Floros

    Full Text Available The use of microwaves in every day's applications raises issues regarding the non thermal biological effects of microwaves. In this work we employ molecular dynamics simulations to advance further the dielectric studies of protein solutions in the case of lysozyme, taking into consideration possible frequency dependent changes in the structural and dynamic properties of the system upon application of electric field in the microwave region. The obtained dielectric spectra are identical with those derived in our previous work using the Fröhlich-Kirkwood approach in the framework of the linear response theory. Noticeable structural changes in the protein have been observed only at frequencies near its absorption maximum. Concerning Cα position fluctuations, different frequencies affected different regions of the protein sequence. Furthermore, the influence of the field on the kinetics of protein-water as well as on the water-water hydrogen bonds in the first hydration shell has been studied; an extension of the Luzar-Chandler kinetic model was deemed necessary for a better fit of the applied field results and for the estimation of more accurate hydrogen bond lifetime values.

  1. The Use of Design Models of Wind-Electric Set with a Horizontal Axis of Rotation of the Wind Wheel for Dynamic Calculations at Urban Development

    Directory of Open Access Journals (Sweden)

    Konstantinov Igor

    2016-01-01

    Full Text Available The issues of modern urban development raise a significant question about an environmental cleanliness of progressing cities. Energy sources which are running on fuel cause tremendous harm to the atmosphere. Therefore, special attention is paid to the rational use of natural renewable resources such as wind and solar energy. Wind-electric sets, or wind turbines, are able to work autonomously, which is also important for the development of modern “smart” cities. Currently, the most commonly used design of wind turbines is the system which has the form of a tower of circular cross section (also called pipe, which carries at the upper end a nacelle with wind wheel. When such a system is being designed in urban conditions the wind pulsation and seismic calculations are added to the standard calculations. These added calculations are dynamic loads. It is known that in the process of solution of dynamic tasks design models of various levels of approximation can be used. It occurs due to stages of the design and other factors. The question of errors, which are associated with the use of a dissected, or partitioned, design scheme, raises.

  2. Groundwater discharge to wetlands driven by storm and flood events: Quantification using continuous Radon-222 and electrical conductivity measurements and dynamic mass-balance modelling

    Science.gov (United States)

    Gilfedder, B. S.; Frei, S.; Hofmann, H.; Cartwright, I.

    2015-09-01

    The dynamic response of groundwater discharge to external influences such as rainfall is an often neglected part of water and solute balances in wetlands. Here we develop a new field platform for long-term continuous 222Rn and electrical conductivity (EC) measurements at Sale Wetland, Australia to study the response of groundwater discharge to storm and flood events. The field measurements, combined with dynamic mass-balance modelling, demonstrate that the groundwater flux can increase from 3 to ∼20 mm d-1 following storms and up to 5 mm d-1 on the receding limb of floods. The groundwater pulses are likely produced by activation of local groundwater flow paths by water ponding on the surrounding flood plains. While 222Rn is a sensitive tracer for quantifying transient groundwater discharge, the mass-balance used to estimate fluxes is sensitive to parameterisation of gas exchange (k) with the atmosphere. Comparison of six equations for calculating k showed that, based on parameterisation of k alone, the groundwater flux estimate could vary by 58%. This work shows that neglecting transient processes will lead to errors in water and solute flux estimates based on infrequent point measurements. This could be particularly important for surface waters connected to contaminated or saline groundwater systems.

  3. Functional profile of the giant metacerebral neuron of Helix aspersa: temporal and spatial dynamics of electrical activity in situ

    Science.gov (United States)

    Antic, Srdjan; Wuskell, Joseph P; Loew, Leslie; Zecevic, Dejan

    2000-01-01

    Understanding the biophysical properties of single neurons and how they process information is fundamental to understanding how the brain works. However, action potential initiation and the preceding integration of the synaptic signals in neuronal processes of individual cells are complex and difficult to understand in the absence of detailed, spatially resolved measurements. Multi-site optical recording with voltage-sensitive dyes from individual neurons in situ was used to provide these kinds of measurements. We analysed in detail the pattern of initiation and propagation of spikes evoked synaptically in an identified snail (Helix aspersa) neuron in situ. Two main spike trigger zones were identified. The trigger zones were activated selectively by different sets of synaptic inputs which also produced different spike propagation patterns. Synaptically evoked action potentials did not always invade all parts of the neuron. The conduction of the axonal spike was regularly blocked at particular locations on neuronal processes. The propagating spikes in some axonal branches consistently reversed direction at certain branch points, a phenomenon known as reflection. These experimental results, when linked to a computer model, could allow a new level of analysis of the electrical structure of single neurons. PMID:10944170

  4. The dynamic calibration of an electrical capacitance tomography sensor applied to the fluidized bed drying of pharmaceutical granule

    Science.gov (United States)

    Chaplin, Gareth; Pugsley, Todd; van der Lee, Loni; Kantzas, Apostolos; Winters, Conrad

    2005-06-01

    Electrical capacitance tomographic data collected in a lab-scale fluidized bed used for the drying of pharmaceutical granule have been corrected for the influence of moisture on the permittivity of the drying material. The correction is based on a linear least-squares fit to measurements of capacitance in a packed bed of granule at various moisture contents. X-ray tomography has been used to independently verify this correction procedure. The influence of permittivity models and number of iterations used for the reconstruction of tomograms have also been examined. It has been determined that the Böttcher permittivity model performs best at bed moistures above approximately 5 wt% while the parallel model is superior at bed moisture below this value. The reconstruction technique based on iterative linear back-projection utilized for the reconstruction of ECT data required approximately 50 iterations to successfully reproduce the density behaviour seen in the x-ray tomographs. Instability in the reconstruction technique at higher numbers of iterations indicates that a linear least-squares fit does not completely capture the response of the sensor to moisture changes. For future applications, changes in bed voidage associated with the drying of pharmaceuticals must be addressed and included in this calibration procedure in order to implement this calibration technique throughout the drying process. Nevertheless, the viability of this technique for on-line calibration of an ECT sensor applied to the drying process has been demonstrated.

  5. Complex risk analysis for loss of electric power in liquid metal nuclear reactor by system dynamics (SD) method

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Tae Ho [Seoul National Univ. (Korea, Republic of). Dept. of Nuclear Engineering

    2012-07-15

    The power stabilization of the nuclear power plants (NPPs) is investigated in the aspect of the liquid metal coolant. The quantification of the risk analysis is performed by the system dynamics (SD) method which is processed by the feedback and accumulation complex algorithms. The Vensim software package is used for the simulations, which is supported by the Monte-Carlo method. There are 2 kinds of considerations as the economic and safety properties. The result shows the stability of the operations when the power can be decided. This shows the higher efficiency of the reactor. The failure frequency is 16/60 = 27%. In the event of Power Stabilized, the failure event is in the quite lower frequency rate. The commercial use of the reactor is important in the operations. (orig.)

  6. Molecular dynamics simulations of metallic friction and of its dependence on electric currents - development and first results

    Science.gov (United States)

    Meintanis, Evangelos Anastasios

    We have extended the HOLA molecular dynamics (MD) code to run slider-on-block friction experiments for Al and Cu. Both objects are allowed to evolve freely and show marked deformation despite the hardness difference. We recover realistic coefficients of friction and verify the importance of cold-welding and plastic deformations in dry sliding friction. Our first data also show a mechanism for decoupling between load and friction at high velocities. Such a mechanism can explain an increase in the coefficient of friction of metals with velocity. The study of the effects of currents on our system required the development of a suitable electrodynamic (ED) solver, as the disparity of MD and ED time scales threatened the efficiency of our code. Our first simulations combining ED and MD are presented.

  7. Dynamic effects of adrenaline (epinephrine) in out-of-hospital cardiac arrest with initial pulseless electrical activity (PEA).

    Science.gov (United States)

    Nordseth, Trond; Olasveengen, Theresa Mariero; Kvaløy, Jan Terje; Wik, Lars; Steen, Petter Andreas; Skogvoll, Eirik

    2012-08-01

    In cardiac arrest, pulseless electrical activity (PEA) is a challenging clinical syndrome. In a randomized study comparing intravenous (i.v.) access and drugs versus no i.v. access or drugs during advanced life support (ALS), adrenaline (epinephrine) improved return of spontaneous circulation (ROSC) in patients with PEA. Originating from this study, we investigated the time-dependent effects of adrenaline on clinical state transitions in patients with initial PEA, using a non-parametric multi-state statistical model. Patients with available defibrillator recordings were included, of whom 101 received adrenaline and 73 did not. There were significantly more state transitions in the adrenaline group than in the no-adrenaline group (rate ratio = 1.6, pAdrenaline markedly increased the rate of transition from PEA to ROSC during ALS and slowed the rate of being declared dead; e.g. by 20 min 20% of patients in the adrenaline group had been declared dead and 25% had obtained ROSC, whereas 50% in the no-adrenaline group have been declared dead and 15% had obtained ROSC. The differential effect of adrenaline could be seen after approx. 10 min of ALS for most transitions. For both groups the probability of deteriorating from PEA to asystole was highest during the first 15 min. Adrenaline increased the rate of transition from PEA to ventricular fibrillation or -tachycardia (VF/VT), and from ROSC to VF/VT. Adrenaline has notable clinical effects during ALS in patients with initial PEA. The drug extends the time window for ROSC to develop, but also renders the patient more unstable. Further research should investigate the optimal dose, timing and mode of adrenaline administration during ALS. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  8. An artificial ecosystem model used in the study of social, economic and technological dynamics: An artificial electrical energy market

    Energy Technology Data Exchange (ETDEWEB)

    Arjona, D.

    1998-07-01

    This paper will present the artificial ecosystem as a tool, in the development of multi agent models for the simulation of economic and technological dynamics (as well as other possible applications). This tool is based on the mechanics of an artificial society and consists of autonomous artificial agents that interact with individuals that have different characteristics and behavior and other that have a similar conduct to their own. Initial conditions are assumed not to be controllable, however they can be influenced. The importance of the concept of the ecosystem is in understanding great units in the light of their own components which are relevant for the analysis and become interdependent among themselves and with other essential components that hold the total operation of the system. Ideas for the development of a simulation model based on autonomous intelligent agents are presented. These agents will have a brain that is based on artificial intelligence technologies. The Sand Kings Simulation Model, an artificial ecosystem model developed by the author, is described as well as the application of artificial intelligence to this artificial life model. An application to a real life problem is also offered as an artificial energy market that is currently being developed by the author is described.

  9. Role of actinically provoked systemic elastolysis in polymyalgic vascular disease. A study based on serum fluorescence and haptoglobin

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, J.P.; Argyle, J.C.

    This study of cutaneous elastic tissue and serum fluorescence supports the hypothesis that widespread destruction and resorption of elastic tissue (elastolysis) occurs in the temporal arteritis/polymyalgia rheumatica syndrome. A systemic elastolysis of this nature may be provoked by actinic (radiant) damage to the exposed elastic tissues in the skin and superficial arteries, the archetype of such injury being seen in temporal arteritis. Scattered giant cells are the usual agents of elastolysis but tuberculoid (sarcoid) infiltrates often take over in the later stages. In acute polymyalgia, the phenomenon probably becomes diffuse and humoral. Elastolysis may be a direct pathogenetic link between polymyalgia and other vascular diseases such as idiopathic aneurysm and atherosclerosis.

  10. A Mixed Logical Dynamical-Model Predictive Control (MLD-MPC Energy Management Control Strategy for Plug-in Hybrid Electric Vehicles (PHEVs

    Directory of Open Access Journals (Sweden)

    Jing Lian

    2017-01-01

    Full Text Available Plug-in hybrid electric vehicles (PHEVs can be considered as a hybrid system (HS which includes the continuous state variable, discrete event, and operation constraint. Thus, a model predictive control (MPC strategy for PHEVs based on the mixed logical dynamical (MLD model and short-term vehicle speed prediction is proposed in this paper. Firstly, the mathematical model of the controlled PHEV is set-up to evaluate the energy consumption using the linearized models of core power components. Then, based on the recognition of driving intention and the past vehicle speed data, a nonlinear auto-regressive (NAR neural network structure is designed to predict the vehicle speed for known driving profiles of city buses and the predicted vehicle speed is used to calculate the total required torque. Next, a MLD model is established with appropriate constraints for six possible driving modes. By solving the objective function with the Mixed Integer Linear Programming (MILP algorithm, the optimal motor torque and the corresponding driving mode sequence within the speed prediction horizon can be obtained. Finally, the proposed energy control strategy shows substantial improvement in fuel economy in the simulation results.

  11. Análisis vibrodinámico de motores eléctricos // Vibrational and dynamic analysis of electric motors

    Directory of Open Access Journals (Sweden)

    Orestes González-Quintero

    2010-01-01

    Full Text Available ResumenEl artículo aborda el estudio vibrodinámico ejecutado en motores eléctricos de la fábrica de azúcar“Cristino Naranjo” durante la implementación del mantenimiento predictivo. En el mismo seexponen los trabajos realizados en las diferentes etapas de implementación del mantenimiento y eldiagnóstico de defectos mediante la utilización del análisis espectral de vibraciones. Se muestranespectros de motor con problemas y en funcionamiento normal.Palabras claves: Ingeniería de Mantenimiento, Mantenimiento Predictivo, análisis, vibraciones.__________________________________________________________________________________AbstractThis work is concerned with the vibrational and dynamic study of electrical motors located inCristino Naranjo sugar mill. It is done during the predictive maintenance implementation. At thesome time some works are shown during this process as well the failures diagnostic by means ofthe use of spectrum analysis of vibration. The spectrums shown are related to motors withdifficulties or well working.Key words: Maintenance Engineering, Predictive Maintenance, vibration, análisis.

  12. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2)

    Energy Technology Data Exchange (ETDEWEB)

    Bourg, I.C.; Sposito, G.

    2011-04-01

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl{sup 2} electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO{sub 2} or high-level radioactive waste (0.34-1.83 mol{sub c} dm{sup -3}). Our results confirm the existence of three distinct ion adsorption planes (0-, {beta}-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the {beta}- and d-planes are independent of ionic strength or ion type and (2) 'indifferent electrolyte' ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl{sup +} ion pairs. Therefore, at concentrations 0.34 mol{sub c} dm{sup -3}, properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid 'ice-like' structures for water on clay mineral surfaces.

  13. Utilizing multichannel electrical resistivity methods to examine the dynamics of the fresh water–seawater interface in two Hawaiian groundwater systems

    Science.gov (United States)

    Dimova, Natasha T.; Swarzenski, Peter W.; Dulaiova, Henrieta; Glenn, Craig R.

    2012-01-01

    Multichannel electrical resistivity (ER) measurements were conducted at two contrasting coastal sites in Hawaii to obtain new information on the spatial scales and dynamics of the fresh water–seawater interface and rates of coastal groundwater exchange. At Kiholo Bay (located on the dry, Kona side of the Big Island) and at a site in Maunalua Bay (Oahu), there is an evidence for abundant submarine groundwater discharge (SGD). However, the hydrologic and geologic controls on coastal groundwater discharge are likely to be different at these two sites. While at Kiholo Bay SGD is predominantly through lava tubes, at the Maunalua Bay site exchange occurs mostly through nearshore submarine springs. In order to calculate SGD fluxes, it is important to understand the spatial and temporal scales of coastal groundwater exchange. From ER time series data, subsurface salinity distributions were calculated using site-specific formation factors. A salinity mass balance box model was then used to calculate rates of point source (i.e., spatially discreet) and total fresh water discharge. From these data, mean SGD rates were calculated for Kiholo Bay (∼9,200 m3/d) and for the Maunalua Bay site (∼5,900 m3/d). While such results are on the same order of magnitude to geochemical tracer-derived SGD rates, the ER SGD rates provide enhanced details of coastal groundwater exchange that can enable a more cohesive whole watershed perspective.

  14. A Control Law Definition of the Open Loop Stepping Electric Drive

    Directory of Open Access Journals (Sweden)

    A. B. Krasovskii

    2015-01-01

    Full Text Available The paper considers an open loop stepping electric drive (SEP with electric crushing of a step and motor fed from the controlled current invertor which should meet the requirement that is to trial a free-form guided trajectory with a split-hair accuracy. It is shown that with traditional programmed control, when the SEP forms motor phase currents of identical amplitude and variable frequency proportional to the set speed of movement, there may be considerable errors reducing a trial accuracy of the set movement trajectory, dynamic indicators provoking oscillatory processes, and even loss of motor synchronism because influence on a dynamic moment of the motor is impossible.The paper offers and proves a new way to define a control algorithm adequate to drive parameters and programmed trajectory of movement, providing error minimization and thereby increasing trial accuracy of set parameters of movement and expanding dynamic capabilities of a drive. The essence of the offered way is to use a modified mathematical model of a drive in d,q coordinates with a motor fed by the current source. In this model a programmed trajectory of movement is chosen as an input action while solving the appropriate equations defines the necessary law of control. The paper describes a developed simulation model of the stepping electric drive in the environment of MATLAB – SIMULINK, which has been used to verify and prove an efficiency of the offered method to define a control law via typical examples.It is established that no error trial of set movement trajectory in case it has breaks (jogs is technically unfeasible, as it demands an infinitely high forcing voltage of the power supply to maintain the instant positive or negative phase shifts of currents formed in the motor windings.The obtained results can be used in designing programmable precision SEPs in robots, numerically controlled machine tools, and assembly equipment.

  15. Transdisciplinary electric power grid science

    CERN Document Server

    Brummitt, Charles D; Dobson, Ian; Moore, Cristopher; D'Souza, Raissa M

    2013-01-01

    The 20th-century engineering feat that most improved the quality of human life, the electric power system, now faces discipline-spanning challenges that threaten that distinction. So multilayered and complex that they resemble ecosystems, power grids face risks from their interdependent cyber, physical, social and economic layers. Only with a holistic understanding of the dynamics of electricity infrastructure and human operators, automatic controls, electricity markets, weather, climate and policy can we fortify worldwide access to electricity.

  16. Electricity Customers

    Science.gov (United States)

    This page discusses key sectors and how they use electricity. Residential, commercial, and industrial customers each account for roughly one-third of the nation’s electricity use. The transportation sector also accounts for a small fraction of electricity.

  17. Mitochondrial DNA mutations provoke dominant inhibition of mitochondrial inner membrane fusion.

    Directory of Open Access Journals (Sweden)

    Cécile Sauvanet

    Full Text Available Mitochondria are highly dynamic organelles that continuously move, fuse and divide. Mitochondrial dynamics modulate overall mitochondrial morphology and are essential for the proper function, maintenance and transmission of mitochondria and mitochondrial DNA (mtDNA. We have investigated mitochondrial fusion in yeast cells with severe defects in oxidative phosphorylation (OXPHOS due to removal or various specific mutations of mtDNA. We find that, under fermentative conditions, OXPHOS deficient cells maintain normal levels of cellular ATP and ADP but display a reduced mitochondrial inner membrane potential. We demonstrate that, despite metabolic compensation by glycolysis, OXPHOS defects are associated to a selective inhibition of inner but not outer membrane fusion. Fusion inhibition was dominant and hampered the fusion of mutant mitochondria with wild-type mitochondria. Inhibition of inner membrane fusion was not systematically associated to changes of mitochondrial distribution and morphology, nor to changes in the isoform pattern of Mgm1, the major fusion factor of the inner membrane. However, inhibition of inner membrane fusion correlated with specific alterations of mitochondrial ultrastructure, notably with the presence of aligned and unfused inner membranes that are connected to two mitochondrial boundaries. The fusion inhibition observed upon deletion of OXPHOS related genes or upon removal of the entire mtDNA was similar to that observed upon introduction of point mutations in the mitochondrial ATP6 gene that are associated to neurogenic ataxia and retinitis pigmentosa (NARP or to maternally inherited Leigh Syndrome (MILS in humans. Our findings indicate that the consequences of mtDNA mutations may not be limited to OXPHOS defects but may also include alterations in mitochondrial fusion. Our results further imply that, in healthy cells, the dominant inhibition of fusion could mediate the exclusion of OXPHOS-deficient mitochondria from

  18. Ictal brain SPET during seizures pharmacologically provoked with pentylenetetrazol: a new diagnostic procedure in drug-resistant epileptic patients

    Energy Technology Data Exchange (ETDEWEB)

    Calcagni, Maria Lucia; Giordano, Alessandro; Bruno, Isabella; Di Giuda, Daniela; De Rossi, Giuseppe; Troncone, Luigi [Department of Nuclear Medicine, Universita Cattolica del Sacro Cuore, Largo A. Gemelli, 8, 00168 Roma (Italy); Parbonetti, Giovanni; Colicchio, Gabriella [Department of Neurosurgery, Universita Cattolica del Sacro Cuore, Roma (Italy)

    2002-10-01

    Functional brain imaging plays an important role in seizure focus localisation. However, truly ictal single-photon emission tomography (SPET) studies are not routinely performed owing to technical problems associated with the use of tracers and methodological and logistical difficulties. In this study we tried to resolve both of these issues by means of a new procedure: technetium-99m ethyl cysteinate dimer (ECD) brain SPET performed during seizures pharmacologically provoked with pentylenetetrazol, a well-known central and respiratory stimulant. We studied 33 drug-resistant epileptic patients. All patients underwent anamnestic evaluation, neuropsychological and psychodynamic assessment, magnetic resonance imaging, interictal and ictal video-EEG monitoring, and interictal and ictal SPET with {sup 99m}Tc-ECD. In order to obtain truly ictal SPET, 65 mg of pentylenetetrazol was injected every 2 minutes and, immediately the seizure began, 740 MBq of {sup 99m}Tc-ECD was injected. The scintigraphic findings were considered abnormal if a single area of hyperperfusion was present and corresponded to the site of a single area of hypoperfusion at interictal SPET: the ''hypo-hyperperfusion'' SPET pattern. In 27 of the 33 patients (82%), interictal-ictal SPET showed the hypo-hyperperfusion SPET pattern. Video-EEG showed a single epileptogenic zone in 21/33 patients (64%), and MRI showed anatomical lesions in 19/33 patients (57%). Twenty-two of the 27 patients with hypo-hyperperfusion SPET pattern underwent ablative or palliative surgery and were seizure-free at 3 years of follow-up. No adverse effects were noted during pharmacologically provoked seizure. It is concluded that ictal brain SPET performed during pharmacologically provoked seizure provides truly ictal images because {sup 99m}Tc-ECD is injected immediately upon seizure onset. Using this feasible procedure it is possible to localise the focus, to avoid the limitations due to the unpredictability

  19. Dig1 protects against cell death provoked by glyphosate-based herbicides in human liver cell lines

    Directory of Open Access Journals (Sweden)

    Travert Carine

    2010-10-01

    Full Text Available Abstract Background Worldwide used pesticides containing different adjuvants like Roundup formulations, which are glyphosate-based herbicides, can provoke some in vivo toxicity and in human cells. These pesticides are commonly found in the environment, surface waters and as food residues of Roundup tolerant genetically modified plants. In order to know their effects on cells from liver, a major detoxification organ, we have studied their mechanism of action and possible protection by precise medicinal plant extracts called Dig1. Methods The cytotoxicity pathways of four formulations of glyphosate-based herbicides were studied using human hepatic cell lines HepG2 and Hep3B, known models to study xenobiotic effects. We monitored mitochondrial succinate dehydrogenase activity and caspases 3/7 for cell mortality and protection by Dig1, as well as cytochromes P450 1A1, 1A2, 3A4 and 2C9 and glutathione-S-transferase to approach the mechanism of actions. Results All the four Roundup formulations provoke liver cell death, with adjuvants having stronger effects than glyphosate alone. Hep3B are 3-5 times more sensitive over 48 h. Caspases 3/7 are greatly activated in HepG2 by Roundup at non-cytotoxic levels, and some apoptosis induction by Roundup is possible together with necrosis. CYP3A4 is specifically enhanced by Roundup at doses 400 times less than used in agriculture (2%. CYP1A2 is increased to a lesser extent together with glutathione-S-transferase (GST down-regulation. Dig 1, non cytotoxic and not inducing caspases by itself, is able to prevent Roundup-induced cell death in a time-dependant manner with an important efficiency of up to 89%, within 48 h. In addition, we evidenced that it prevents Caspases 3/7 activation and CYP3A4 enhancement, and not GST reduction, but in turn it slightly inhibited CYP2C9 when added before Roundup. Conclusion Roundup is able to provoke intracellular disruption in hepatic cell lines at different levels, but a

  20. Investigating the structure and dynamics of microbial communities in zones of anomalous geophysical signatures and the effect of these communities on electrical properties

    Science.gov (United States)

    Allen, J. P.; Atekwana, E. A.; Davis, C.; Slater, L.; Eversole, R. R.; Rossbach, S.

    2005-05-01

    It has been recently recognized that microorganisms can impact both the electrolytic and interfacial electrical properties of subsurface geologic media and thereby influencing geoelectrical measurements. We hypothesize that geoelectrical methods in turn, can be used to delineate subsurface zones containing maximal microbial activity allowing for a better understanding of geomicrobiological processes and characterization of the microbial community. To investigate the structure and dynamics of microbial communities in zones of anomalous geophysical signatures, we used traditional culture-based microbiological and non-culture-based molecular methods. The employment of culture-based enrichment techniques at a hydrocarbon-polluted study site resulted in the isolation of multiple strains of the bacterial Rhodococcus species. Since it is known that only a fraction of the microbial soil community is amenable to enrichment cultures, we chose a non-culture-based approach as well. We constructed two clone libraries based on the 16S rRNA gene of bacteria, one from the hydrocarbon-contaminated study site and one from a non-contaminated background site. The comparison of the two clone libraries will reveal whether there is any significant difference in microbial community composition associated with areas of anomalous geoelectrical measurements. Moreover, to study the effects of microbial biofilm formation on the physical properties of sediments, we inoculated sterile sand with known bacterial cultures and monitored the biofilm formation over time using colorimetric dyes and microscopic methods. Increased biofilm formation was observed between 3 and 6 days after inoculation. Resulting changes in the porosity and surface area of the sands will be measured by induced polarization methods. This interdisciplinary project between geophysicists and microbiologists will enhance our understanding of the effects of microorganisms on geologic media and their influence on geoelectrical

  1. [Type V phosphodiesterase inhibitor erection-provoking test with audio-visual sexual stimulation for the diagnosis of erectile dysfunction].

    Science.gov (United States)

    Zhu, Xuan-Wen; Guo, Jun-Ping; Zhang, Feng-Bin; Zhong, Da-Chuan; Fang, Jia-Jie; Li, Fang-Yin

    2008-05-01

    To evaluate the type V phosphodiesterase (PDE-5) inhibitor erection-provoking test with audio-visual sexual stimulation in the diagnosis of erectile dysfunction. A total of 853 out-patients diagnosed with erectile dysfunction were divided into an injury and a non-injury group. After scored on IIEF-5 questionnaires, all the patients received oral administration of PDE-5 inhibitors and, 30 minutes later, audio-visual sexual stimulation. The data on penile erection were recorded with Rigiscan Plus. The patients with mild, moderate and severe ED accounted for 18.8, 31.9 and 49.3% in the injury group, and 50.6, 39.8 and 9.6% in the non-injury group, with statistic differences between the two groups in the mild and severe parts (P erectile dysfunction.

  2. High voltage electricity installations a planning perspective

    CERN Document Server

    Jay, Stephen Andrew

    2006-01-01

    The presence of high voltage power lines has provoked widespread concern for many years. High Voltage Electricity Installations presents an in-depth study of policy surrounding the planning of high voltage installations, discussing the manner in which they are percieved by the public, and the associated environmental issues. An analysis of these concerns, along with the geographical, environmental and political influences that shape their expression, is presented. Investigates local planning policy in an area of the energy sector that is of highly topical environmental and public concern Cover

  3. Electrical conduction in graphene and nanotubes

    CERN Document Server

    Fujita, Shigeji

    2013-01-01

    Written in a self-contained manner, this textbook allows both advanced students and practicing applied physicists and engineers to learn the relevant aspects from the bottom up. All logical steps are laid out without omitting steps.The book covers electrical transport properties in carbon based materials by dealing with statistical mechanics of carbon nanotubes and graphene ? presenting many fresh and sometimes provoking views. Both second quantization and superconductivity are covered and discussed thoroughly. An extensive list of references is given in the end of each chapter, while derivati

  4. Breakdown electric fields in dissociated hot gas mixtures of sulfur hexafluoride including teflon: Calculations with experimental validations and utilization in fluid dynamics arc simulations

    Science.gov (United States)

    Yousfi, M.; Merbahi, N.; Reichert, F.; Petchanka, A.

    2017-03-01

    Measurements of breakdown voltage Vb, gas temperature Tg, and density N and the associated critical electric field Ecr/N are performed in hot dissociated SF6 highly diluted in argon and in hot dissociated SF6 mixed with PTFE (Polytetrafluoroethylene or C2F4) also highly diluted in argon. Gases are heated using a microwave source and optical emission spectroscopy is used for measurements of Tg and N while Vb is measured from a specific inter-electrode arrangement placed inside of the cell of the hot gas conditioning. The experimental Ecr/N data in the numerous considered cases of gas temperatures and compositions have been used to evaluate and validate the sets of the collision cross sections of the 11 species involved in hot dissociated SF6 (i.e., SF6, SF5, SF4, S2F2, SF3, SF2, SF, S2, F2, F, and S), the 13 additional species involved either in hot C2F4 or CF4 (C2F6, C2F4, C2F2, CF4, CF3, CF2, CF, F2, F and carbon species as C, C2, C3, C4) and also the 2 further species (CS and CS2) present only in the considered mixtures SF6 + C2F4. The fitted sets of collision cross sections of all these 26 species are then used without argon dilution in hot SF6 and hot SF6 + C2F4 mixtures to calculate and to analyze the Ecr/N data obtained for a wide range of gas temperature (up to 4000 K) and gas pressure (8 bar and more) using a rigorous multi-term solution of the Boltzmann equation for electron energy distribution function and standard calculations of hot gas composition for the species proportions. Such Ecr/N data have been then successfully used to evaluate from a Computational Fluid Dynamics model the switching capacity at terminal fault from a coupled simulation of the electrostatic field and the hot gas flow after current zero.

  5. Electric Cars and Oil Prices

    OpenAIRE

    Azar, Jose

    2009-01-01

    This paper studies the joint dynamics of oil prices and interest in electric cars, measured as the volume of Google searches for related phrases. Not surprisingly, I find that oil price shocks predict increases in Google searches for electric cars. Much more surprisingly, I also find that an increase in Google searches predicts declines in oil prices. The high level of public interest in electric cars between April and August of 2008 can explain approximately half of the decline in oil prices...

  6. Levelised cost of electricity 2015

    Energy Technology Data Exchange (ETDEWEB)

    Stolzenberger, Christian; Then, Oliver [VGB PowerTech e.V., Essen (Germany)

    2015-07-01

    The electricity business is currently subject to dynamic and permanent change that is driven by innovation, learning curves and modifications of the electricity generation mix. A new edition of the ''Levelised Cost of Electricity (LCOE)'' was drafted under these circumstances. The fundamental idea behind the LCOE is to calculate the yearly average costs of building and operating plants and to compare these with the average energy generated each year.

  7. It Takes Two: Sexual Communication Patterns and the Sexual and Relational Adjustment of Couples Coping With Provoked Vestibulodynia.

    Science.gov (United States)

    Rancourt, Kate M; Flynn, Michelle; Bergeron, Sophie; Rosen, Natalie O

    2017-03-01

    Provoked vestibulodynia (PVD) is a prevalent vulvovaginal pain condition that is associated with sexual and relational consequences for women and their partners. Greater perceived quality of sexual communication has been associated with women's lower pain during intercourse and with couples' better sexual and relational well-being. Whether couples' collaborative (eg, expressing feelings or problem solving) and negative (eg, withdrawing or criticizing) sexual communication patterns (SCPs) are differentially associated with couples' adjustment to PVD is unknown. To examine associations between collaborative and negative SCPs and women's pain and the sexual and relationship adjustment of women with PVD and their partners. Women diagnosed with PVD (N = 87) and their partners completed the Sexual Communication Patterns Questionnaire and measurements of pain (women only), sexual functioning, sexual satisfaction, sexual distress, and relationship satisfaction. (i) Numerical rating scale of pain during intercourse, (ii) Female Sexual Function Index and International Index of Erectile Function, (iii) Global Measure of Sexual Satisfaction, (iv) Female Sexual Distress Scale-Revised, and (v) Couple Satisfaction Index. When women reported greater collaborative SCP, they also reported higher sexual and relationship satisfaction. When women reported greater negative SCP, they reported less relationship satisfaction and had partners who reported greater sexual distress. When partners reported greater collaborative SCP, they also reported higher relationship satisfaction and had female partners who were less sexually distressed. When partners reported higher negative SCP, they also reported less relationship satisfaction. There were no associations between SCP and women's or partners' sexual functioning or women's pain. Collaborative SCP may benefit couples' sexual and relational well-being, whereas negative SCP may impede sexual and relational adjustment to PVD. Findings

  8. Soumitro Banerjee Department of Electrical Engineering Indian ...

    Indian Academy of Sciences (India)

    QUALITATIVE CHANGES IN DYNAMICAL STATUS. THEORY AND OPEN PROBLEMS. Soumitro Banerjee. Department of Electrical Engineering. Indian Institute of Technology. Kharagpur — 721302, India. QUALITATIVE CHANGES IN DYNAMICAL STATUS... 1 ...

  9. Electrical contracting

    CERN Document Server

    Neidle, Michael

    2013-01-01

    Electrical Contracting, Second Edition is a nine-chapter text guide for the greater efficiency in planning and completing installations for the design, installation and control of electrical contracts. This book starts with a general overview of the efficient cabling and techniques that must be employed for safe wiring design, as well as the cost estimation of the complete electrical contract. The subsequent chapters are devoted to other electrical contracting requirements, including electronic motor control, lighting, and electricity tariffs. A chapter focuses on the IEE Wiring Regulations an

  10. Teratocarcinomas Arising from Allogeneic Induced Pluripotent Stem Cell-Derived Cardiac Tissue Constructs Provoked Host Immune Rejection in Mice.

    Science.gov (United States)

    Kawamura, Ai; Miyagawa, Shigeru; Fukushima, Satsuki; Kawamura, Takuji; Kashiyama, Noriyuki; Ito, Emiko; Watabe, Tadashi; Masuda, Shigeo; Toda, Koichi; Hatazawa, Jun; Morii, Eiichi; Sawa, Yoshiki

    2016-01-14

    Transplantation of induced pluripotent stem cell-derived cardiac tissue constructs is a promising regenerative treatment for cardiac failure: however, its tumourigenic potential is concerning. We hypothesised that the tumourigenic potential may be eliminated by the host immune response after allogeneic cell transplantation. Scaffold-free iPSC-derived cardaic tissue sheets of C57BL/6 mouse origin were transplanted into the cardiac surface of syngeneic C57BL/6 mice and allogeneic BALB/c mice with or without tacrolimus injection. Syngeneic mice and tacrolimus-injected immunosuppressed allogeneic mice formed teratocarcinomas with identical phenotypes, characteristic, and time courses, as assessed by imaging tools including (18)F-fluorodeoxyglucose-positron emission tomography. In contrast, temporarily immunosuppressed allogeneic mice, following cessation of tacrolimus injection displayed diminished progression of the teratocarcinoma, accompanied by an accumulation of CD4/CD8-positive T cells, and finally achieved complete elimination of the teratocarcinoma. Our results indicated that malignant teratocarcinomas arising from induced pluripotent stem cell-derived cardiac tissue constructs provoked T cell-related host immune rejection to arrest tumour growth in murine allogeneic transplantation models.

  11. Responses to scenarios that may provoke acts of conflict and aggression among the general public: an exploratory study.

    Science.gov (United States)

    Lowe, Nathan C; May, David C

    2011-05-01

    The purpose of this article is to use empirical research and theory to investigate the context that may provoke individuals to engage in acts of conflict and aggression. A random sample of the general public from a midsouthern state was surveyed to explore this inquiry. Respondents were asked to indicate their level of reaction to a number of situations that often lead people to engage in conflict and/or aggression with other people. Several sociodemographic factors served as control variables in the study. The findings of the Pearson product-moment correlations suggest that respondents were more likely to report that they would respond more aggressively as the situations presented to them were perceived as being more physically threatening to them and/or their loved ones. Also, gender and age were the most significant predictors of engagement in acts of conflict and aggression in the multiple ordinal least squares regression analyses. Strengths and drawbacks of the study and direction of future research are also discussed.

  12. Randomized clinical trial of multimodal physiotherapy treatment compared to overnight lidocaine ointment in women with provoked vestibulodynia: Design and methods.

    Science.gov (United States)

    Morin, Mélanie; Dumoulin, Chantale; Bergeron, Sophie; Mayrand, Marie-Hélène; Khalifé, Samir; Waddell, Guy; Dubois, Marie-France

    2016-01-01

    Provoked vestibulodynia (PVD) is a highly prevalent and debilitating condition yet its management relies mainly on non-empirically validated interventions. Among the many causes of PVD, there is growing evidence that pelvic floor muscle (PFM) dysfunctions play an important role in its pathophysiology. Multimodal physiotherapy, which addresses these dysfunctions, is judged by experts to be highly effective and is recommended as a first-line treatment. However, the effectiveness of this promising intervention has been evaluated through only two small uncontrolled trials. The proposed bi-center, single-blind, parallel group, randomized controlled trial (RCT) aims to evaluate the efficacy of multimodal physiotherapy and compare it to a frequently used first-line treatment, topical overnight application of lidocaine, in women with PVD. A total of 212 women diagnosed with PVD according to a standardized protocol were eligible for the study and were randomly assigned to either multimodal physiotherapy or lidocaine treatment for 10weeks. The primary outcome measure is pain during intercourse (assessed with a numerical rating scale). Secondary measures include sexual function, pain quality, psychological factors (including pain catastrophizing, anxiety, depression and fear of pain), PFM morphology and function, and patients' global impression of change. Assessments are made at baseline, post-treatment and at the 6-month follow-up. This manuscript presents and discusses the rationale, design and methodology of the first RCT investigating physiotherapy in comparison to a commonly prescribed first-line treatment, overnight topical lidocaine, for women with PVD. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Caffeine provokes adverse interactions with 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’) and related psychostimulants: mechanisms and mediators

    Science.gov (United States)

    Vanattou-Saïfoudine, N; McNamara, R; Harkin, A

    2012-01-01

    Concomitant consumption of caffeine with recreational psychostimulant drugs of abuse can provoke severe acute adverse reactions in addition to longer term consequences. The mechanisms by which caffeine increases the toxicity of psychostimulants include changes in body temperature regulation, cardiotoxicity and lowering of the seizure threshold. Caffeine also influences the stimulatory, discriminative and reinforcing effects of psychostimulant drugs. In this review, we consider our current understanding of such caffeine-related drug interactions, placing a particular emphasis on an adverse interaction between caffeine and the substituted amphetamine, 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’), which has been most recently described and characterized. Co-administration of caffeine profoundly enhances the acute toxicity of MDMA in rats, as manifested by high core body temperature, tachycardia and increased mortality. In addition, co-administration of caffeine enhances the long-term serotonergic neurotoxicity induced by MDMA. Observations to date support an interactive model of drug-induced toxicity comprising MDMA-related enhancement of dopamine release coupled to a caffeine-mediated antagonism of adenosine receptors in addition to inhibition of PDE. These experiments are reviewed together with reports of caffeine-related drug interactions with cocaine, d-amphetamine and ephedrine where similar mechanisms are implicated. Understanding the underlying mechanisms will guide appropriate intervention strategies for the management of severe reactions and potential for increased drug-related toxicity, resulting from concomitant caffeine consumption. PMID:22671762

  14. Upregulations of Clcn3 and P-Gp Provoked by Lens Osmotic Expansion in Rat Galactosemic Cataract

    Directory of Open Access Journals (Sweden)

    Lixia Ji

    2017-01-01

    Full Text Available Objective. Lens osmotic expansion, provoked by overactivated aldose reductase (AR, is the most essential event of sugar cataract. Chloride channel 3 (Clcn3 is a volume-sensitive channel, mainly participating in the regulation of cell fundamental volume, and P-glycoprotein (P-gp acts as its modulator. We aim to study whether P-gp and Clcn3 are involved in lens osmotic expansion of galactosemic cataract. Methods and Results. In vitro, lens epithelial cells (LECs were primarily cultured in gradient galactose medium (10–60 mM, more and more vacuoles appeared in LEC cytoplasm, and mRNA and protein levels of AR, P-gp, and Clcn3 were synchronously upregulated along with the increase of galactose concentration. In vivo, we focused on the early stage of rat galactosemic cataract, amount of vacuoles arose from equatorial area and scattered to the whole anterior capsule of lenses from the 3rd day to the 9th day, and mRNA and protein levels of P-gp and Clcn3 reached the peak around the 9th or 12th day. Conclusion. Galactosemia caused the osmotic stress in lenses; it also markedly leads to the upregulations of AR, P-gp, and Clcn3 in LECs, together resulting in obvious osmotic expansion in vitro and in vivo.

  15. Error-provoking conditions in the medication use process: the case of a government hospital in Ghana.

    Science.gov (United States)

    Koffuor, George Asumeng; Anto, Berko Panyin; Abaitey, Alfred K

    2012-03-01

    This study aimed to explore error-provoking factors prevalent in hospitals that have the potential to cause medication errors and to create awareness of the existence of medication errors. A total of 200 medical folders of in-patients in the health facility were randomly selected and assessed based on a checklist to record potential medication errors. The medication use process and working environment as well as drug packages and labels in the pharmacy were observed, and potential medication errors were documented. Of the 162 valid in-patient folders studied, 60.5% of the patients did not receive the actual quantity of drugs they were supposed to. Illegible handwriting on medication orders and prescription were common observations in the folders studied. Look-alike medicine packages and labeling were found. The working space in the dispensary was congested, and distractions (e.g., ringing personal telephones, being called from one task to attend to another, and unnecessary conversation between personnel) were common. This study has highlighted the vulnerability of the medication use process in the study site to medication errors. The findings may just be a tip of the iceberg; therefore, the researchers plan undertaking a multicenter study. In the absence of that, however, there is a need for a national policy on patient safety, and a national policy on incident reporting would help in determining the incidence, types, and potential causes of medication errors to improve patient safety.

  16. Reduced striatal activation during reward anticipation due to appetite-provoking cues in chronic schizophrenia: a fMRI study.

    Science.gov (United States)

    Grimm, O; Vollstädt-Klein, S; Krebs, L; Zink, M; Smolka, M N

    2012-02-01

    The occurrence of weight gain in schizophrenia (SZ) has profound clinical impact and interacts with antipsychotic medication, life style and disease severity. The functional neuroanatomy underlying altered nutritional behavior is unraveled, but dysregulated reward anticipation might be one of the involved neuronal mechanisms. The striatum, a core region of the reward network and salience attribution, was previously shown to regulate appetite perception and eating behavior. We studied patients suffering from chronic schizophrenia with a stable medication in comparison to age and gender matched healthy adults. Every subject had to undergo a 6h fasting period before a newly developed, appetite-provoking fMRI task was applied. Subjects saw visual stimuli of appetitive food items in a 3Tesla scanner. In healthy controls food images elicited stronger activation in the striatum compared to SZ patients. When adjusting a ROI-based striatal activation for medication and weight, the group difference remained still significant. This points an effect of illness independent of antipsychotic medication. These data underscore the involvement of the striatum into salience attribution, reward anticipation and the neuronal pathways leading to altered eating behavior and weight gain in schizophrenia. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Reproduction and mode of delivery in women with vaginismus or localised provoked vestibulodynia: a Swedish register-based study.

    Science.gov (United States)

    Möller, L; Josefsson, A; Bladh, M; Lilliecreutz, C; Sydsjö, G

    2015-02-01

    To compare sociodemographics, parity and mode of delivery between women diagnosed with vaginismus or localised provoked vestibulodynia (LPV) to women without a diagnosis before first pregnancy. Retrospective, population-based register study. Sweden. All women born in Sweden 1973-83 who gave birth for the first time or remained nulliparous during the years 2001-09. Nationally linked registries were used to identify the study population. Women diagnosed with vaginismus or LPV were compared to all other women. Odds ratios for parity and mode of delivery were calculated using multinominal regression analysis and logistic regression. Parity and mode of delivery. Women with vaginismus/LPV were more likely to be unmarried (P = 0.001), unemployed (P = 0.012), have a higher educational level (P vaginismus/LPV more often delivered by caesarean section (P vaginismus/LPV were more likely to suffer a perineal laceration (adjusted OR 1.87, 95% CI 1.56-2.25). Women with vaginismus/LPV are less likely to give birth and those that do are more likely to deliver by caesarean section and have a caesarean section based upon maternal request. Those women delivering vaginally are more likely to suffer perineal laceration. These findings point to the importance of not only addressing sexual function in women with vaginismus/LPV but reproductive function as well. © 2014 Royal College of Obstetricians and Gynaecologists.

  18. Exogenous interleukin-6, interleukin-13, and interferon-gamma provoke pulmonary abnormality with mild edema in enterovirus 71-infected mice

    Directory of Open Access Journals (Sweden)

    Huang Szu-Wei

    2011-11-01

    Full Text Available Abstract Background Neonatal mice developed neurological disease and pulmonary dysfunction after an infection with a mouse-adapted human Enterovirus 71 (EV71 strain MP4. However, the hallmark of severe human EV71 infection, pulmonary edema (PE, was not evident. Methods To test whether EV71-induced PE required a proinflammatory cytokine response, exogenous pro-inflammatory cytokines were administered to EV71-infected mice during the late stage of infection. Results After intracranial infection of EV71/MP4, 7-day-old mice developed hind-limb paralysis, pulmonary dysfunction, and emphysema. A transient increase was observed in serum IL-6, IL-10, IL-13, and IFN-γ, but not noradrenaline. At day 3 post infection, treatment with IL-6, IL-13, and IFN-γ provoked mild PE and severe emphysema that were accompanied by pulmonary dysfunction in EV71-infected, but not herpes simplex virus-1 (HSV-1-infected control mice. Adult mice did not develop PE after an intracerebral microinjection of EV71 into the nucleus tractus solitarii (NTS. While viral antigen accumulated in the ventral medulla and the NTS of intracerebrally injected mice, neuronal loss was observed in the ventral medulla only. Conclusions Exogenous IL-6, IL-13, and IFN-γ treatment could induce mild PE and exacerbate pulmonary abnormality of EV71-infected mice. However, other factors such as over-activation of the sympathetic nervous system may also be required for the development of classic PE symptoms.

  19. Provoking, disturbing, hacking

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    2013-01-01

    The article is a discussion of works by two Danish composers who both, with self-constructed instruments challenge computer music both as genre, the understanding and use of conventional technology and the relation to history. At first glance, the use of the homemade instruments appears as a comm...

  20. Provoking, disturbing, hacking

    DEFF Research Database (Denmark)

    Groth, Sanne Krogh

    Among the artists on the contemporary Danish scene of computer music and sound art the musician and composer Goodiepal (Gæoudjiparl van den Dobbelsteen or Parl Kristian Bjørn Vester) is by no comparison the most controversial and provocative. This statement is applicable whether we meet him as mu...

  1. Sexual and relationship intimacy among women with provoked vestibulodynia and their partners: associations with sexual satisfaction, sexual function, and pain self-efficacy.

    Science.gov (United States)

    Bois, Katy; Bergeron, Sophie; Rosen, Natalie O; McDuff, Pierre; Grégoire, Catherine

    2013-08-01

    Provoked vestibulodynia (PVD) is the most frequent subtype of vulvodynia. Women report negative consequences of PVD on their sexual and romantic relationships. Researchers have recently highlighted the importance of examining interpersonal factors such as intimacy, and of including both women and their partners in study designs. The aim of this study was to investigate sexual and relationship intimacy as defined by the Interpersonal Process Model of Intimacy and their associations with sexual satisfaction, sexual function, pain self-efficacy, and pain intensity among women with PVD and their partners. Ninety-one heterosexual women (M age = 27.38, SD = 6.04) diagnosed with PVD and their partners (M age = 29.37, SD = 7.79) completed measures of sexual and relationship intimacy, sexual satisfaction, sexual function, pain self-efficacy, and pain intensity. Dependent measures were the (i) Global Measure of Sexual Satisfaction Scale; (ii) Female Sexual Function Index; (iii) Painful Intercourse Self-Efficacy Scale; and (iv) visual analog scale of pain intensity during intercourse. After controlling for women's age, women's greater sexual intimacy (β = 0.49, P satisfaction and higher pain self-efficacy (β = 0.39, P = 0.001), beyond the effects of partners' sexual intimacy. Also, women's greater sexual intimacy (β = 0.24, P = 0.05) and women's greater relationship intimacy (β = 0.54, P = 0.003) were associated with greater women's sexual function, beyond the effects of partners' sexual and relationship intimacy. Women's self-reported sexual and relationship intimacy in the couple relationship may promote higher sexual satisfaction, sexual function, and pain self-efficacy, as well as possibly foster greater sexual well-being among women with PVD. The authors discuss implications for the inclusion of emotional and interpersonal aspects of the couple's dynamic in clinical interventions and future research in PVD. © 2013

  2. Influence of frequency of the excitation magnetic field and material's electric conductivity on domain wall dynamics in ferromagnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Chávez-González, A.F. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F., México (Mexico); Pérez-Benítez, J.A., E-mail: benitez_edl@yahoo.es [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F., México (Mexico); Espina-Hernández, J.H. [Laboratorio de Evaluación No Destructiva Electromagnética (LENDE), ESIME-SEPI, Edif. Z-4, Instituto Politécnico Nacional, Zacatenco, México D.F., México (Mexico); Grössinger, R. [Institute of Solid State Physics, Vienna University of Technology, Vienna (Austria); Hallen, J.M. [Departamento de Ingeniería Metalúrgica, ESIQIE, UPALM Edif. 7, Instituto Politécnico Nacional, Zacatenco, C.P. 07738, México D.F., México (Mexico)

    2016-03-01

    The present work analyzes the influence of electric conductivity on the Magnetic Barkhausen Noise (MBN) signal using a microscopic model which includes the influence of eddy currents. This model is also implemented to explain the dependence of MBN on the frequency of the applied magnetic field. The results presented in this work allow analyzing the influence of eddy currents on MBN signals for different values of the material's electric conductivity and for different frequencies of applied magnetic field. Additionally, the outcomes of this research can be used as a reference to differentiate the influence of eddy currents from that of second phase particles in the MBN signal, which has been reported in previous works. - Highlights: • Electromagnetic simulation of MBN with eddy currents and micro-magnetism. • Influence of applied field frequency on MBN is explained. • Influence of electric conductivity on MBN is analyzed. • Hysteresis losses in ferromagnetic materials is analyzed using the model.

  3. Electric drive design methodology

    CERN Document Server

    Jufer, Marcel

    2013-01-01

    An electric drive that is designed or adapted to a specific application must take into account all the elements of the chain of constituent elements in its use and deployment. In addition to the motor, the transmission, power electronics, control, sensors, and electrical protection systems must be taken into account. The motor and the transmission can be optimized and designed to obtain the best energy efficiency assessment, in particular for dynamic nodes. An inventory and a characterization of these various components is proposed as part of this book's examination and explanation

  4. Infusion of sodium bicarbonate in experimentally induced metabolic acidosis does not provoke cerebrospinal fluid (CSF) acidosis in calves.

    Science.gov (United States)

    Abeysekara, Saman; Zello, Gordon A; Lohmann, Katharina L; Alcorn, Jane; Hamilton, Don L; Naylor, Jonathan M

    2012-01-01

    In a crossover study, 5 calves were made acidotic by intermittent intravenous infusion of isotonic hydrochloric acid (HCl) over approximately 24 h. This was followed by rapid (4 h) or slow (24 h) correction of blood pH with isotonic sodium bicarbonate (NaHCO(3)) to determine if rapid correction of acidemia produced paradoxical cerebrospinal fluid (CSF) acidosis. Infusion of HCl produced a marked metabolic acidosis with respiratory compensation. Venous blood pH (mean ± S(x)) was 7.362 ± 0.021 and 7.116 ± 0.032, partial pressure of carbon dioxide (Pco(2), torr) 48.8 ± 1.3 and 34.8 ± 1.4, and bicarbonate (mmol/L), 27.2 ± 1.27 and 11 ± 0.96; CSF pH was 7.344 ± 0.031 and 7.240 ± 0.039, Pco(2) 42.8 ± 2.9 and 34.5 ± 1.4, and bicarbonate 23.5 ± 0.91 and 14.2 ± 1.09 for the period before the infusion of hydrochloric acid and immediately before the start of sodium bicarbonate correction, respectively. In calves treated with rapid infusion of sodium bicarbonate, correction of venous acidemia was significantly more rapid and increases in Pco(2) and bicarbonate in CSF were also more rapid. However, there was no significant difference in CSF pH. After 4 h of correction, CSF pH was 7.238 ± 0.040 and 7.256 ± 0.050, Pco(2) 44.4 ± 2.2 and 34.2 ± 2.1, and bicarbonate 17.8 ± 1.02 and 14.6 ± 1.4 for rapid and slow correction, respectively. Under the conditions of this experiment, rapid correction of acidemia did not provoke paradoxical CSF acidosis.

  5. Duodenal-jejunal bypass liner implantation provokes rapid weight loss and improved glycemic control, accompanied by elevated fasting ghrelin levels.

    Science.gov (United States)

    Koehestanie, Parweez; Dogan, Kemal; Berends, Frits; Janssen, Ignace; Wahab, Peter; Groenen, Marcel; Müller, Michael; de Wit, Nicole

    2014-03-01

    Endoscopic implantation of a duodenal-jejunal bypass liner (DJBL) is a novel bariatric technique to induce weight loss and remission of type 2 diabetes mellitus. Placement of the DJBL mimics the bypass component of the Roux-en-Y gastric bypass (RYGB) procedure. In this observational study, we evaluated improvement of glycemic control and weight loss in the course of the treatment (0 - 24 weeks after DJBL implantation) and analyzed accompanying gut hormone responses. 12 obese individuals with type 2 diabetes were selected for DJBL implantation. Body weight, fat mass, and fasting plasma levels of glucose, insulin, C-peptide, and glycated hemoglobin (HbA1c), were analyzed at 0, 1, 4 and 24 weeks post-implant. Fasting ghrelin, gastric inhibitory peptide (GIP), and glucagon-like peptide (GLP-1) were determined at 0, 1 and 4 weeks post-implant. Besides significant weight loss, fat mass, fasting insulin, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) index were also significantly decreased after DJBL implantation and a 42 % reduction was found in diabetes medication (P response in the first 4 weeks post-implant was significantly correlated with the fasting insulin and HOMA-IR response. Fasting ghrelin was found to be significantly elevated, in contrast to the decrease in ghrelin that is found after RYGB surgery. DJBL implantation provoked significant weight loss, a decrease in fat mass, and an early remission of type 2 diabetes, comparable to results seen after RYGB surgery. Gut hormone analyses revealed a potential role of fasting GLP-1 in early remission of type 2 diabetes. Interestingly, the DJBL-induced elevation of ghrelin contradicts the suggested role of reduced ghrelin levels after RYGB in improvement of glycemic control.

  6. Attenuation of microRNA-16 derepresses the cyclins D1, D2 and E1 to provoke cardiomyocyte hypertrophy

    Science.gov (United States)

    Huang, Shuai; Zou, Xiao; Zhu, Jie-Ning; Fu, Yong-Heng; Lin, Qiu-Xiong; Liang, Ye-You; Deng, Chun-Yu; Kuang, Su-Juan; Zhang, Meng-Zhen; Liao, Yu-Lin; Zheng, Xi-Long; Yu, Xi-Yong; Shan, Zhi-Xin

    2015-01-01

    Cyclins/retinoblastoma protein (pRb) pathway participates in cardiomyocyte hypertrophy. MicroRNAs (miRNAs), the endogenous small non-coding RNAs, were recognized to play significant roles in cardiac hypertrophy. But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy. This study investigates the potential role of microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy. An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC), and in a mouse with transverse aortic constriction (TAC) and in a mouse with subcutaneous injection of phenylephrine (PE) respectively. In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte and based on Ang-II-induced neonatal mouse ventricular cardiomyocyte respectively. We demonstrated that miR-16 expression was markedly decreased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats and mice. Overexpression of miR-16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes, and inhibition of miR-16 induced a hypertrophic phenotype in cardiomyocytes. Expressions of cyclins D1, D2 and E1, and the phosphorylated pRb were increased in hypertrophic myocardium and hypertrophic cardiomyocytes, but could be reversed by enforced expression of miR-16. Cyclins D1, D2 and E1, not pRb, were further validated to be modulated post-transcriptionally by miR-16. In addition, the signal transducer and activator of transcription-3 and c-Myc were activated during myocardial hypertrophy, and inhibitions of them prevented miR-16 attenuation. Therefore, attenuation of miR-16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2 and E1, and activating cyclin/Rb pathway, revealing that miR-16 might be a target to manage cardiac hypertrophy. PMID:25583328

  7. Memory-provoked rCBF-SPECT as a diagnostic tool in Alzheimer's disease?

    Energy Technology Data Exchange (ETDEWEB)

    Sundstroem, Torbjoern; Riklund, Katrine Aa. [Umeaa University, Umeaa University Hospital, Department of Radiation Sciences, Diagnostic Radiology, Umeaa (Sweden); Elgh, Eva; Naesman, Birgitta [Umeaa University, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeaa (Sweden); Larsson, Anne [Umeaa University, Department of Radiation Sciences, Radiation Physics, Umeaa (Sweden); Nyberg, Lars [Umeaa University, Department of Psychology, Umeaa (Sweden)

    2006-01-01

    Alzheimer's disease (AD) is a primary degenerative disease that progressively affects all brain functions, with devastating consequences for the patient, the patient's family and society. Rest regional cerebral blood flow (rCBF) could have a strategic role in differentiating between AD patients and normal controls, but its use for this purpose has a low discriminatory capacity. The purpose of this study was to evaluate whether the diagnostic sensitivity of rCBF single-photon emission computed tomography (SPECT) could be increased by using an episodic memory task provocation, i.e. memory-provoked rCBF-SPECT (MP-SPECT). Eighteen persons (73.2{+-}4.8 years) with mild AD and 18 healthy elderly (69.4{+-}3.9 years) were included in the study. The subjects were injected with{sup 99m}Tc-hexamethylpropylene amine oxime (HMPAO) during memory provocation with faces and names, followed by an rCBF-SPECT study. The rCBF{sup 99m}Tc-HMPAO SPECT images were analysed using statistical parametric mapping (SPM2). Peaks with a false discovery rate corrected value of 0.05 were considered significant. On MP-SPECT, the AD group showed a significant rCBF reduction in the left parietal cortex in comparison with healthy elderly. At rest, no significant group differences were seen. Memory provocation increased the sensitivity of rCBF-SPECT for the detection of AD-related blood flow changes in the brain at the group level. Further studies are needed to evaluate MP-SPECT as a diagnostic tool at the individual level. If a higher sensitivity for AD at the individual level is verified in future studies, a single MP-SPECT study might be sufficient in the clinical setting. (orig.)

  8. Pristanic acid provokes lipid, protein, and DNA oxidative damage and reduces the antioxidant defenses in cerebellum of young rats.

    Science.gov (United States)

    Busanello, Estela Natacha Brandt; Lobato, Vannessa Gonçalves Araujo; Zanatta, Ângela; Borges, Clarissa Günther; Tonin, Anelise Miotti; Viegas, Carolina Maso; Manfredini, Vanusa; Ribeiro, César Augusto João; Vargas, Carmen Regla; de Souza, Diogo Onofre Gomes; Wajner, Moacir

    2014-12-01

    Zellweger syndrome (ZS) and some peroxisomal diseases are severe inherited disorders mainly characterized by neurological symptoms and cerebellum abnormalities, whose pathogenesis is poorly understood. Biochemically, these diseases are mainly characterized by accumulation of pristanic acid (Prist) and other fatty acids in the brain and other tissues. In this work, we evaluated the in vitro influence of Prist on redox homeostasis by measuring lipid, protein, and DNA damage, as well as the antioxidant defenses and the activities of aconitase and α-ketoglutarate dehydrogenase in cerebellum of 30-day-old rats. The effect of Prist on DNA damage was also evaluated in blood of these animals. Some parameters were also evaluated in cerebellum from neonatal rats and in cerebellum neuronal cultures. Prist significantly increased malondialdehyde (MDA) levels and carbonyl formation and reduced sulfhydryl content and glutathione (GSH) concentrations in cerebellum of young rats. It also caused DNA strand damage in cerebellum and induced a high micronuclei frequency in blood. On the other hand, this fatty acid significantly reduced α-ketoglutarate dehydrogenase and aconitase activities in rat cerebellum. We also verified that Prist-induced increase of MDA levels was totally prevented by melatonin and attenuated by α-tocopherol but not by the nitric oxide synthase inhibitor N(ω)-nitro-L-arginine methyl ester, indicating the involvement of reactive oxygen species in this effect. Cerebellum from neonate rats also showed marked alterations of redox homeostasis, including an increase of MDA levels and a decrease of sulfhydryl content and GSH concentrations elicited by Prist. Finally, Prist provoked an increase of dichlorofluorescein (DCFH) oxidation in cerebellum-cultivated neurons. Our present data indicate that Prist compromises redox homeostasis in rat cerebellum and blood and inhibits critical enzymes of the citric acid cycle that are susceptible to free radical attack. The

  9. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  10. Electric Substations

    Data.gov (United States)

    Department of Homeland Security — Substations. Substations are facilities and equipment that switch, transform, or regulate electric voltage. The Substations feature class includes taps, a location...

  11. Electric vehicle integration into modern power networks

    CERN Document Server

    Garcia-Valle, Rodrigo

    2012-01-01

    Electric Vehicle Integration into Modern Power Networks provides coverage of the challenges and opportunities posed by the progressive integration of electric drive vehicles. Starting with a thorough overview of the current electric vehicle and battery state-of-the-art, this work describes dynamic software tools to assess the impacts resulting from the electric vehicles deployment on the steady state and dynamic operation of electricity grids, identifies strategies to mitigate them and the possibility to support simultaneously large-scale integration of renewable energy sources.New business mo

  12. Structural and Functional Effect of an Oscillating Electric Field on the Dopamine-D3 Receptor: A Molecular Dynamics Simulation Study.

    Science.gov (United States)

    Fallah, Zohreh; Jamali, Yousef; Rafii-Tabar, Hashem

    2016-01-01

    Dopamine as a neurotransmitter plays a critical role in the functioning of the central nervous system. The structure of D3 receptor as a member of class A G-protein coupled receptors (GPCRs) has been reported. We used MD simulation to investigate the effect of an oscillating electric field, with frequencies in the range 0.6-800 GHz applied along the z-direction, on the dopamine-D3R complex. The simulations showed that at some frequencies, the application of an external oscillating electric field along the z-direction has a considerable effect on the dopamine-D3R. However, there is no enough evidence for prediction of changes in specific frequency, implying that there is no order in changes. Computing the correlation coefficient parameter showed that increasing the field frequency can weaken the interaction between dopamine and D3R and may decrease the Arg128{3.50}-Glu324{6.30} distance. Because of high stability of α helices along the z-direction, applying an oscillating electric field in this direction with an amplitude 10-time higher did not have a considerable effect. However, applying the oscillating field at the frequency of 0.6 GHz along other directions, such as X-Y and Y-Z planes, could change the energy between the dopamine and the D3R, and the number of internal hydrogen bonds of the protein. This can be due to the effect of the direction of the electric field vis-à-vis the ligands orientation and the interaction of the oscillating electric field with the dipole moment of the protein.

  13. Railway diagnosis of electric transport

    Directory of Open Access Journals (Sweden)

    Yushkov Vladimir Sergeevich

    2015-01-01

    Full Text Available The increase in noise level at cities is increasing the requirements to functional interaction of road users - pedestrians and drivers - with the parameters of the environment as a leading component of Afferentation synthesis in the complicated complex of locomotive activity. City noise is one of the most widespread factors of unfavorable living and working conditions. The noise of high intensity provokes diseases, lowers labor activity. At present, many large cities pay much attention to electric vehicles. The authors present an analysis of the poor state of tram track in areas of high noise and vibration of car and under-sleeper base design. A negative effect of noise and vibration on the formation of urban areas environment is shown as well as the impact of these conditions on the person. The advantages of the application of electric transport are specified, noise displacement curve of railway and under sleeper base is plotted depending on the frequency of the applied load and the modulus of elasticity, as well as under sleeper base vibroacceleration depending on time. The authors offer a systematic study on the basis of a mathematical model of the sources of noise in the process of a tram motion.

  14. Rethinking Sediment Biogeochemistry After the Discovery of Electric Currents

    Science.gov (United States)

    Nielsen, Lars Peter; Risgaard-Petersen, Nils

    2015-01-01

    The discovery of electric currents in marine sediments arose from a simple observation that conventional biogeochemistry could not explain: Sulfide oxidation in one place is closely coupled to oxygen reduction in another place, centimeters away. After experiments demonstrated that this resulted from electric coupling, the conductors were found to be long, multicellular, filamentous bacteria, now known as cable bacteria. The spatial separation of oxidation and reduction processes by these bacteria represents a shortcut in the conventional cascade of redox processes and may drive most of the oxygen consumption. In addition, it implies a separation of strong proton generators and consumers and the formation of measurable electric fields, which have several effects on mineral development and ion migration. This article reviews the work on electric currents and cable bacteria published through April 2014, with an emphasis on general trends, thought-provoking consequences, and new questions to address.

  15. Electric machine

    Science.gov (United States)

    El-Refaie, Ayman Mohamed Fawzi [Niskayuna, NY; Reddy, Patel Bhageerath [Madison, WI

    2012-07-17

    An interior permanent magnet electric machine is disclosed. The interior permanent magnet electric machine comprises a rotor comprising a plurality of radially placed magnets each having a proximal end and a distal end, wherein each magnet comprises a plurality of magnetic segments and at least one magnetic segment towards the distal end comprises a high resistivity magnetic material.

  16. Non-invasive neuromuscular electrical stimulation in patients with central nervous system lesions: an educational review.

    Science.gov (United States)

    Schuhfried, Othmar; Crevenna, Richard; Fialka-Moser, Veronika; Paternostro-Sluga, Tatjana

    2012-02-01

    The aim of this educational review is to provide an overview of the clinical application of transcutaneous electrical stimulation of the extremities in patients with upper motor neurone lesions. In general two methods of electrical stimulation can be distinguished: (i) therapeutic electrical stimulation, and (ii) functional electrical stimulation. Therapeutic electrical stimulation improves neuromuscular functional condition by strengthening muscles, increasing motor control, reducing spasticity, decreasing pain and increasing range of motion. Transcutaneous electrical stimulation may be used for neuromuscular electrical stimulation inducing repetitive muscle contraction, electromyography-triggered neuromuscular electrical stimulation, position-triggered electrical stimulation and subsensory or sensory transcutaneous electric stimulation. Functional electrical stimulation provokes muscle contraction and thereby produces a functionally useful movement during stimulation. In patients with spinal cord injuries or stroke, electrical upper limb neuroprostheses are applied to enhance upper limb and hand function, and electrical lower limb neuroprostheses are applied for restoration of standing and walking. For example, a dropped foot stimulator is used to trigger ankle dorsiflexion to restore gait function. A review of the literature and clinical experience of the use of therapeutic electrical stimulation as well as of functional electrical stimulation in combination with botulinum toxin, exercise therapy and/or splinting are presented. Although the evidence is limited we conclude that neuromuscular electrical stimulation in patients with central nervous system lesions can be an effective modality to improve function, and that combination with other treatments has an additive therapeutic effect.

  17. Dynamic Kerr effect in a strong uniform AC electric field for interacting polar and polarizable molecules in the mean field approximation

    Science.gov (United States)

    Deshmukh, Snehal D.; Déjardin, Pierre-Michel; Kalmykov, Yuri P.

    2017-09-01

    Analytical formulas for the electric birefringence response of interacting polar and anisotropically polarizable molecules due to a uniform alternating electric field are derived using Berne's forced rotational diffusion model [B. J. Berne, J. Chem. Phys. 62, 1154 (1975)] in the nonlinear version described by Warchol and Vaughan [J. Chem. Phys. 71, 502 (1979)]. It is found for noninteracting molecules that the signal consists of a frequency-dependent DC component superimposed on an oscillatory part with a frequency twice that of the AC driving field. However, unlike noninteracting molecules, the AC part strongly deviates from its dilute counterpart. This suggests a possible way of motivating new experimental studies of intermolecular interactions involving electro-optical methods and complementary nonlinear dielectric relaxation experiments.

  18. Dynamics of Ring Current and Electric Fields in the Inner Magnetosphere During Disturbed Periods: CRCM-BATS-R-US Coupled Model

    Science.gov (United States)

    Buzulukova, N.; Fok, M.-C.; Pulkkinen, A.; Kuznetsova, M.; Moore, T. E.; Glocer, A.; Brandt, P. C.; Toth, G.; Rastaetter, L.

    2010-01-01

    We present simulation results from a one-way coupled global MHD model (Block-Adaptive-Tree Solar-Wind Roe-Type Upwind Scheme, BATS-R-US) and kinetic ring current models (Comprehensive Ring Current Model, CRCM, and Fok Ring Current, FokRC). The BATS-R-US provides the CRCM/FokRC with magnetic field information and plasma density/temperature at the polar CRCM/FokRC boundary. The CRCM uses an electric potential from the BATS-R-US ionospheric solver at the polar CRCM boundary in order to calculate the electric field pattern consistent with the CRCM pressure distribution. The FokRC electric field potential is taken from BATS-R-US ionospheric solver everywhere in the modeled region, and the effect of Region II currents is neglected. We show that for an idealized case with southward-northward-southward Bz IMF turning, CRCM-BATS-R-US reproduces well known features of inner magnetosphere electrodynamics: strong/weak convection under the southward/northward Bz; electric field shielding/overshielding/penetration effects; an injection during the substorm development; Subauroral Ion Drift or Polarization Jet (SAID/PJ) signature in the dusk sector. Furthermore, we find for the idealized case that SAID/PJ forms during the substorm growth phase, and that substorm injection has its own structure of field-aligned currents which resembles a substorm current wedge. For an actual event (12 August 2000 storm), we calculate ENA emissions and compare with Imager for Magnetopause-to-Aurora Global Exploration/High Energy Neutral Atom data. The CRCM-BATS-R-US reproduces both the global morphology of ring current and the fine structure of ring current injection. The FokRC-BATS-R-US shows the effect of a realistic description of Region II currents in ring current-MHD coupled models.

  19. A Molecular Dynamics of Cold Neutral Atoms Captured by Carbon Nanotube Under Electric Field and Thermal Effect as a Selective Atoms Sensor.

    Science.gov (United States)

    Santos, Elson C; Neto, Abel F G; Maneschy, Carlos E; Chen, James; Ramalho, Teodorico C; Neto, A M J C

    2015-05-01

    Here we analyzed several physical behaviors through computational simulation of systems consisting of a zig-zag type carbon nanotube and relaxed cold atoms (Rb, Au, Si and Ar). These atoms were chosen due to their different chemical properties. The atoms individually were relaxed on the outside of the nanotube during the simulations. Each system was found under the influence of a uniform electric field parallel to the carbon nanotube and under the thermal effect of the initial temperature at the simulations. Because of the electric field, the cold atoms orbited the carbon nanotube while increasing the initial temperature allowed the variation of the radius of the orbiting atoms. We calculated the following quantities: kinetic energy, potential energy and total energy and in situ temperature, molar entropy variation and average radius of the orbit of the atoms. Our data suggest that only the action of electric field is enough to generate the attractive potential and this system could be used as a selected atoms sensor.

  20. Fecal sacs attract insects to the nest and provoke an activation of the immune system of nestlings.

    Science.gov (United States)

    Ibáñez-Álamo, Juan Diego; Ruiz-Raya, Francisco; Rodríguez, Laura; Soler, Manuel

    2016-01-01

    Nest sanitation is a widespread but rarely studied behavior in birds. The most common form of nest sanitation behavior, the removal of nestling feces, has focused the discussion about which selective pressures determine this behavior. The parasitism hypothesis, which states that nestling fecal sacs attract parasites that negatively affect breeding birds, was proposed 40 years ago and is frequently cited as a demonstrated fact. But, to our knowledge, there is no previous experimental test of this hypothesis. We carried out three different experiments to investigate the parasitism hypothesis. First, we used commercial McPhail traps to test for the potential attraction effect of nestling feces alone on flying insects. We found that traps with fecal sacs attracted significantly more flies (Order Diptera), but not ectoparasites, than the two control situations. Second, we used artificial blackbird (Turdus merula) nests to investigate the combined attraction effect of feces and nest materials on arthropods (not only flying insects). Flies, again, were the only group of arthropods significantly attracted by fecal sacs. We did not detect an effect on ectoparasites. Third, we used active blackbird nests to investigate the potential effect of nestling feces in ecto- and endoparasite loads in real nestlings. The presence of fecal sacs near blackbird nestlings did not increase the number of louse flies or chewing lice, and unexpectedly reduced the number of nests infested with mites. The endoparasite prevalence was also not affected. In contrast, feces provoked an activation of the immune system as the H/L ratio of nestlings living near excrements was significantly higher than those kept under the two control treatments. Surprisingly, our findings do not support the parasitism hypothesis, which suggests that parasites are not the main reason for fecal sac removal. In contrast, the attraction of flies to nestling feces, the elevation of the immune response of chicks, and the

  1. Visceral hypersensitivity is provoked by 2,4,6-trinitrobenzene sulfonic acid-induced ileitis in rats

    Directory of Open Access Journals (Sweden)

    Manoj Kumar Shah

    2016-07-01

    Full Text Available Background and Aims: Crohn’s Disease (CD, a chronic Inflammatory Bowel Disease, can occur in any part of the gastrointestinal tract, but most frequently in the ileum. Visceral hypersensitivity contributes for development of chronic abdominal pain in this disease. Currently, the understanding of the mechanism underlying hypersensitivity of Crohn’s ileitis has been hindered by a lack of specific animal model. The present study is undertaken to investigate the visceral hypersensitivity provoked by 2,4,6-trinitrobenzene sulfonic (TNBS-induced ileitis rats.Methods: Male Sprague-Dawley rats were anaesthetized and laparotomized for intraileal injection of TNBS (0.6 ml, 80 mg/kg body weight in 30% ethanol, n = 48, an equal volume of 30% Ethanol (n = 24 and Saline (n = 24, respectively. Visceral hypersensitivity was assessed by visceromotor responses (VMR to 20, 40, 60, 80 and 100 mmHg colorectal distension pressure (CRD at day 1, 3, 7, 14, 21 and 28. Immediately after CRD test, the rats were euthanized for collecting the terminal ileal segment for histopathological examinations and ELISA of myleoperoxidase and cytokines (TNF-α, IL-1β, IL-6, and dorsal root ganglia (T11 for determination of calcitonin gene-related peptide by immunohistochemistry, respectively. Results: Among all groups, TNBS-treatment showed transmural inflammation initially at 3 days, reached maximum at 7 days and persisted up to 21 days. The rats with ileitis exhibited (P < 0.05 VMR to CRD at day 7 to day 21. The calcitonin gene-related peptide-immunoreactive positive cells increased (P < 0.05 in dorsal root ganglia at day 7 to 21, which was persistently consistent with visceral hypersensitivity in TNBS-treated rats.Conclusions: TNBS injection into the ileum induced transmural ileitis including granuloma and visceral hypersensitivity. As this model mimics clinical manifestations of CD, it may provide a road map to probe the pathogenesis of gut inflammation and visceral

  2. Fucoidan effectively provokes the innate immunity of white shrimp Litopenaeus vannamei and its resistance against experimental Vibrio alginolyticus infection.

    Science.gov (United States)

    Kitikiew, Suwaree; Chen, Jiann-Chu; Putra, Dedi Fazriansyah; Lin, Yong-Chin; Yeh, Su-Tuen; Liou, Chyng-Hwa

    2013-01-01

    In this study, we examined the effect of fucoidan on the immune response of white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus infection. Fucoidan induced degranulation, caused changes in the cell morphology, and increased activation of prophenoloxidase (proPO) and the production of superoxide anions in vitro. Shrimp that received fucoidan via immersion at 100, 200, and 400 mg l(-1) after 3 h showed haemocyte proliferation and a higher mitotic index of haematopoietic tissue. In another experiment, the haemocyte count, phenoloxidase (PO) activity, and respiratory bursts (RBs) were examined after the shrimp had been fed diets containing fucoidan at 0 (control), 0.5, 1.0, and 2.0 g kg(-1) for 7-21 days. Results indicated that these parameters directly increased with time. The immune parameters of shrimp fed the 1.0 g kg(-1) diet were significantly higher than those of shrimp fed the 2.0 g kg(-1) diet after 14 and 21 days. Phagocytic activity and the clearance efficiency against V. alginolyticus were significantly higher in shrimp fed the 1.0 g kg(-1) diet compared to those of shrimp fed the 0, 0.5 and 2.0 g kg(-1) diets. In a separate experiment, shrimp that had been fed diets containing fucoidan for 21 days were challenged with V. alginolyticus at 10(6) colony-forming units shrimp(-1). Survival rates of shrimp fed the 1.0 and 2.0 g kg(-1) diets were significantly higher than those of shrimp fed the 0 and 0.5 g kg(-1) diets for 96-120 h. We concluded that fucoidan provokes innate immunity of shrimp as evidenced by haemocyte degranulation, proPO activation, and the mitotic index of haematopoietic tissue, and that dietary administration of fucoidan at 1.0 g kg(-1) enhanced the immune response of shrimp and their resistance against V. alginolyticus infection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Poliovirus infection and expression of the poliovirus protein 2B provoke the disassembly of the Golgi complex, the organelle target for the antipoliovirus drug Ro-090179.

    Science.gov (United States)

    Sandoval, I V; Carrasco, L

    1997-06-01

    Infection of Vero cells with poliovirus results in complete disassembly of the Golgi complex. Milestones of the process of disassembly are the release to the cytosol of the beta-COP bound to Golgi membranes, the disruption of the cis-Golgi network into fragments scattered throughout the cytoplasm, and the disassembly of the stacked cisternae by a process mediated by long tubular structures. Transient expression of the viral protein 2B in COS-7 cells also causes the disassembly of the Golgi complex by a process preceded by the accumulation of the protein in the Golgi area. Vero cells infected for 3 h show no recognizable Golgi complexes at the ultrastructural level and display an enormously swollen endoplasmic reticulum (ER) with extensive areas of its surface heavily coated. Ro-090179 (Ro), a flavonoid isolated from the herb Agastache rugosa, provokes the specific swelling and disruption of the Golgi complex and strongly inhibits poliovirus infection. Ro provokes the swelling and the disruption of the stacked cisternae and trans-Golgi elements without affecting the cis-most Golgi cisternae much. Moreover, Ro inhibits the fusion of the Golgi complex with the ER in cells treated with brefeldin A and provokes the accumulation of the intermediate compartment membrane protein p58 into ERD2-positive Golgi elements but has no effect on the anterograde transport involved in protein secretion. Our results indicate that the secretory pathway and specifically the Golgi complex are preferential targets of poliovirus.

  4. Mathematical model of the glucose-insulin regulatory system: From the bursting electrical activity in pancreatic β-cells to the glucose dynamics in the whole body

    Science.gov (United States)

    Han, Kyungreem; Kang, Hyuk; Choi, M. Y.; Kim, Jinwoong; Lee, Myung-Shik

    2012-10-01

    A theoretical approach to the glucose-insulin regulatory system is presented. By means of integrated mathematical modeling and extensive numerical simulations, we probe the cell-level dynamics of the membrane potential, intracellular Ca2+ concentration, and insulin secretion in pancreatic β-cells, together with the whole-body level glucose-insulin dynamics in the liver, brain, muscle, and adipose tissues. In particular, the three oscillatory modes of insulin secretion are reproduced successfully. Such comprehensive mathematical modeling may provide a theoretical basis for the simultaneous assessment of the β-cell function and insulin resistance in clinical examination.

  5. Quantum Scattering of an Electric Dipole by a Charged Screw Dislocation

    Science.gov (United States)

    de Lima Ribeiro, C. A.; de M. Carvalho, A. M.; Furtado, C.

    2010-10-01

    In this contribution we present a study of the quantum scattering of a neutral particle with an induced electric dipole moment in the presence of a charged topological defect exposed to an uniform magnetic field. We consider a geometric modification in the Hamiltonian provoked by charged screw dislocation and a repulsive potential originated from deformation potential theory. We analyze the quantum scattering for this electric dipole by this topological defect. We determine the condition for which it is possible to find a geometric phase acquired by the wave function of the electric dipole.

  6. Application of learning from examples methods for on-line dynamic security assessment of electric power systems - state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Pecas Lopes, J.A. [Universidade do Porto, Porto (Portugal). Faculdade de Engenharia] Hatziargyriou, Nikos D. [National Technical University of Athens, Athens (Greece)

    1994-12-31

    This paper provides an overview of the application of `learning from examples` techniques like pattern recognition, artificial neural networks and decision trees, when used for fast dynamic security assessment. Problems concerning the system security evaluation relatively to transient stability and voltage stability are addressed with more details and references to research works in this field are briefly described. (author) 44 refs., 3 tabs.

  7. Lumbar internal disc derangement in patients with chronic low back pain: diagnostic value of the MR imaging findings as compared with provoked discography as the standard

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyeon Seon; Park, Jee Young; Lee, Sang Ho; Ahn, Yong [Wooridul spine Hospital, Seoul (Korea, Republic of); Lee, Sang Yeun [Puchon Daesung Hospital, Puchon (Korea, Republic of)

    2006-04-15

    The aim of this study was to evaluate the diagnostic value of the MR imaging findings with provoked discography used as the standard for painful lumbar disc derangement. Two hundred patients (412 discs), (age rang: 21-77 year), with chronic low back pain underwent MRI and provoked discography. We evaluated the MRI T2-WI findings such as disc degeneration, high-Intensity zones and endplate abnormalities. Subsequently, provocative discography was independently performed with using MR imaging, and a painful disc was defined when moderate to severe and concordant pain was provoked. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the MRI findings with using provoked discography as the standard. 400 discs showed abnormal findings such as disc degeneration, HIZ and endplate abnormalities on the T2-WI images. 12 discs showed normal finding. HIZ or endplate abnormalities were always combined with disc degeneration. The prevalence of each findings were disc degeneration (400 discs: 97.1%), HIZ (111 discs: 26.9%), type I endplate abnormalities (34 discs: 8.3%), type II endplate abnormalities (75 discs: 18.2%), the combined findings of HIZ and type I endplate abnormalities (2 discs: 0.5%) and the combined findings of HIZ and type II endplate abnormalities (7 discs: 1.7%). The disc degeneration showed high sensitivity (99.5%) and low specificity (5.0%), so only the NPV (91.7%) was significant, and not the PPV (47.8%). Each findings of HIZ (sensitivity, 36.5%, specificity, 81.4%; PPV, 63.18%; NPV, 59.5%), type I endplate abnormalities (11.0%, 94.1%, 61.8% and 54.8%, respectively), type II endplate abnormalities (19.8%, 83.2%, 50.7% and 54.3%, respectively), the combined findings of HIZ and type I endplate abnormalities (0.5%, 99.6%, 50.0% and 53.4%, respectively) and the combined findings of HIZ and type II endplate abnormalities (26.0%, 99.1%, 71.4% and 53.8%, respectively) show high specificity, but low

  8. Electrical Injuries

    Science.gov (United States)

    ... it can pass through your body and cause injuries. These electrical injuries can be external or internal. You may have one or both types. External injuries are skin burns. Internal injuries include damage to ...

  9. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  10. The electric motor handbook

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, R.W.; Feltham, P. (eds.)

    2004-05-01

    This handbook outlines the important role that electric motors play in modern society. It covers the field of motor applications from various motor types to their use and repair. It also presents practical applications of electric motors and methods on motor efficiency. More than half of all electricity generated, and 75 per cent of all industrial electricity consumption is consumed by electric motors. Electrical personnel must be aware of all factors involved in electric motors in order to choose and apply the appropriate size of electric motor. These factors include efficiency, sizing and proper application. The efficient use and maximum life expectancy of electric motors depends on proper motor protection, control and maintenance. This handbook includes articles from leading experts on electric motors in modern electrical systems. The content includes: design considerations; proper electric motor sizing techniques; optimal electric motor application; electric motor protection technology; electric motor control principles; electric motor maintenance and troubleshooting; induction electric motors; electric motor bearing currents; electric motor bearing lubrication; electromagnetism; electric motor enclosures; electric motor testing; electric motor repair; DC electric motor; electric motor starters; electric motor brushes; industrial electric motors; electric motor diagrams; AC electric motors; electric motor wiring; electric motor service; electric motor rewinding; electric motor winding; diagram of electric motor wiring; electric motor kit; and, troubleshooting electric motors. A directory of motor manufacturers and suppliers was also included. refs., tabs., figs.

  11. Electrical utilities model for determining electrical distribution capacity

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, R. L.

    1997-09-03

    In its simplest form, this model was to obtain meaningful data on the current state of the Site`s electrical transmission and distribution assets, and turn this vast collection of data into useful information. The resulting product is an Electrical Utilities Model for Determining Electrical Distribution Capacity which provides: current state of the electrical transmission and distribution systems; critical Hanford Site needs based on outyear planning documents; decision factor model. This model will enable Electrical Utilities management to improve forecasting requirements for service levels, budget, schedule, scope, and staffing, and recommend the best path forward to satisfy customer demands at the minimum risk and least cost to the government. A dynamic document, the model will be updated annually to reflect changes in Hanford Site activities.

  12. Optimal Charge control of Electric Vehicles in Electricity Markets

    DEFF Research Database (Denmark)

    Lan, Tian; Hu, Junjie; Wu, Guang

    2011-01-01

    Environment constraints, petroleum scarcity, high price on fuel resources and recent advancements in battery technology have led to emergence of Electric Vehicles (EVs). As increasing numbers of EVs enter the electricity market, these extra loads may cause peak load and need to be properly...... controlled. In this paper, an algorithm is presented for every individual vehicles to minimize the charging cost while satisfying the vehicle owner’s requirements. The algorithm is based on a given future electricity prices and uses dynamic programming. Optimization aims to find the economically optimal...... solution for each vehicle....

  13. Mathematical model of the glucose–insulin regulatory system: From the bursting electrical activity in pancreatic β-cells to the glucose dynamics in the whole body

    Energy Technology Data Exchange (ETDEWEB)

    Han, Kyungreem [College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Kang, Hyuk [National Institute for Mathematical Sciences, Daejeon 305-340 (Korea, Republic of); Choi, M.Y., E-mail: mychoi@snu.ac.kr [Department of Physics and Astronomy and Center for Theoretical Physics, Seoul National University, Seoul 151-747 (Korea, Republic of); Kim, Jinwoong, E-mail: jwkim@snu.ac.kr [College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742 (Korea, Republic of); Lee, Myung-Shik [Department of Medicine, Samsung Medical Center, and School of Medicine, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of)

    2012-10-01

    A theoretical approach to the glucose–insulin regulatory system is presented. By means of integrated mathematical modeling and extensive numerical simulations, we probe the cell-level dynamics of the membrane potential, intracellular Ca{sup 2+} concentration, and insulin secretion in pancreatic β-cells, together with the whole-body level glucose–insulin dynamics in the liver, brain, muscle, and adipose tissues. In particular, the three oscillatory modes of insulin secretion are reproduced successfully. Such comprehensive mathematical modeling may provide a theoretical basis for the simultaneous assessment of the β-cell function and insulin resistance in clinical examination. -- Highlights: ► We present a mathematical model for the glucose–insulin regulatory system. ► This model combines the microscopic insulin secretion mechanism in a pancreatic β-cell and macroscopic glucose dynamics at the whole-body level. ► This work is expected to provide a theoretical basis for the simultaneous assessment of the β-cell function and insulin resistance in clinical examination.

  14. Electric Vehicle Integration into Modern Power Networks

    DEFF Research Database (Denmark)

    Electric Vehicle Integration into Modern Power Networks provides coverage of the challenges and opportunities posed by the progressive integration of electric drive vehicles. Starting with a thorough overview of the current electric vehicle and battery state-of-the-art, this work describes dynamic...... software tools to assess the impacts resulting from the electric vehicles deployment on the steady state and dynamic operation of electricity grids, identifies strategies to mitigate them and the possibility to support simultaneously large-scale integration of renewable energy sources. New business models...... and control management architectures, as well as the communication infrastructure required to integrate electric vehicles as active demand are presented. Finally, regulatory issues of integrating electric vehicles into modern power systems are addressed. Inspired by two courses held under the EES...

  15. Polarization extension mechanism revealed through dynamic ferroelectric hysteresis and electric field driven structural distortions in lead free Na0.5Bi0.5TiO3 ceramic

    Science.gov (United States)

    Karthik, T.; Asthana, Saket

    2017-09-01

    The electric field amplitude (E o) dependent dynamic ferroelectric hysteresis and polarization current density curves measured at room temperature for Na0.5Bi0.5TiO3 (NBT), showed three different stages of polarization reversal mechanism. The scaling relationship confirmed the dominance of domain wall motion at Stage I (i.e. upto E o  <  35 kV cm-1), followed by domain switching at Stage II (35 kV cm-1  <  E o  <  60 kV cm-1). Interestingly, a unique behaviour with two sub stages was observed in Stage III (60 kV cm-1  <  E o  <  90 kV cm-1), with two distinct switching mechanisms viz., polarization rotation at Stage III-A and polarization extension at Stage III-B. X-ray diffraction analysis based on the Rietveld refined atomic positional co-ordinates, in electrically poled system strongly favors the polarization extension mechanism proposed at Stage III-B. The measured E o-dependent longitudinal piezoelectric response (d 33 and g33) values match closely with our proposed polarization reversal mechanism.

  16. Dynamics of competitive strategies in de-regulated industries: the case of the electricity industry in France; Dynamique des strategies concurrentielles dans un contexte de liberalisation: le cas de l'industrie electrique en France

    Energy Technology Data Exchange (ETDEWEB)

    Cateura, O

    2007-11-15

    This research work is focused on the competitive dynamics approach and rivalry studies between competitors. It develops theses recent perspectives and particularly multi-market competition (also called multipoint competition) in de-regulated industries (network utilities). Indeed, competitive behaviours in liberalized industries are still badly-known. To conduct this research, we decided to analyze a selection of companies (EDF, Electrabel, Endesa, Enel, Gaz de France, Poweo, Direct Energie..) settled on the French electricity market presently in the course of liberalization (1996 - 2006). This qualitative research, through longitudinal case studies, has been developed thanks to a CIFRE agreement (between the French Ministry of Research and the firm Electrabel France) including action research and participant observation. Using multidimensional strategic sequences, we identified two periods, the first one characterized by a confrontation movement and a second one by mutual forbearance. We argue that after learning the rules of a newly liberalized market (confrontation, diversification, internationalization), competitors rapidly and collectively shift there positions towards a focused European strategy based on the gas-electricity convergence. The development of multi-market competition has conducted to mutual forbearance, which was particularly profitable to the major participants. Integrated strategy (market and non-market) appears as an important driver for legitimizing theses behaviours. (author)

  17. Nonlinear dynamic analysis of a punctual charge in the electric field of a charged ring via modified frequency–amplitude formulation

    Directory of Open Access Journals (Sweden)

    S. Valipour

    2016-03-01

    Full Text Available In this paper, two types of frequency amplitude formulation method are initially utilized to obtain frequency–amplitude relationship of nonlinear vibration of a punctual charge in the electric field of a charged ring. In order to obtain the nonlinear natural frequency of the considered system, Reng-Gui and Geng-Cai modified methods are implemented. A table is also prepared to provide a brief review of recent development of nonlinear differential equations. The correctness of the obtained results is compared with those obtained from harmonic balance method (HBM and energy balance method (EBM. A numerical simulation is carried out to investigate the accuracy of the used methods. In accordance with it, the relative errors of the employed approaches are numerically and analytically found based on the exact numerical solutions. It is exposed that the exerted approaches are very reliable and applicable for solving the nonlinear differential equations.

  18. Digital control of electric drives

    CERN Document Server

    Koziol, R; Szklarski, L

    1992-01-01

    The electromechanical systems employed in different branches of industry are utilized most often as drives of working machines which must be fed with electric energy in a continuous, periodic or even discrete way. Some of these machines operate at constant speed, others require wide and varying energy control. In many designs the synchronous cooperation of several electric drives is required in addition to the desired dynamic properties. For these reasons the control of the cooperation and dynamics of electromechanical systems requires the use of computers.This book adopts an unusual approach

  19. Ephemeral Electric Potential and Electric Field Sensor

    Science.gov (United States)

    Generazio, Edward R. (Inventor)

    2017-01-01

    Systems, methods, and devices of the various embodiments provide for the minimization of the effects of intrinsic and extrinsic leakage electrical currents enabling true measurements of electric potentials and electric fields. In an embodiment, an ephemeral electric potential and electric field sensor system may have at least one electric field sensor and a rotator coupled to the electric field sensor and be configured to rotate the electric field sensor at a quasi-static frequency. In an embodiment, ephemeral electric potential and electric field measurements may be taken by rotating at least one electric field sensor at a quasi-static frequency, receiving electrical potential measurements from the electric field sensor when the electric field sensor is rotating at the quasi-static frequency, and generating and outputting images based at least in part on the received electrical potential measurements.

  20. HRCT and bronchial asthma: visualization of the pathophysiologic changes of the pulmonary parenchyma after inhalation provocation; HRCT und Asthma bronchiale: Visualisierung pathophysiologischer Veraenderungen des Lungenparenchyms nach inhalativer Provokation

    Energy Technology Data Exchange (ETDEWEB)

    Schueller, G.; Neumann, K.; Helbich, T.; Herold, C.J. [Univ. Klinik fuer Radiodiagnostik, Abt. fuer konservative Faecher, Vienna (Austria); Riemer, H. [Univ. Klinik fuer Innere Medizin IV, Abt. fuer Pulmologie, Vienna (Austria); Backfrieder, W. [Allgemeines Krankenhaus, Vienna (Austria). Inst. fuer Biomedizinische Technik und Physik; Sertl, K. [Krankenhaus der Stadt Wien-Floridsdorf (Austria). Abt. fuer Innere Medizin; Pittner, B. [Vienna Univ. (Austria). Inst. fuer Medizinische Statistik

    2004-03-01

    alterations of the lung parenchyma subsequent to inhalation provocation. In healthy individuals, these parenchymal alterations were not documented by pulmonary function tests. (orig.) [German] Ziel: Bei Patienten mit leichtem intermittierenden Asthma bronchiale, aber mit Hyperreaktivitaet auch im freien Intervall, und bei gesunden Probanden sollen mithilfe der hoch aufloesenden Computertomographie (HRCT) roentgenmorphologische Veraenderungen des Lungenparenchyms vor sowie nach inhalativer Histaminprovokation und darauf folgender Lyse durch Salbutamol charakterisiert und mit Ergebnissen von Lungenfunktionstests (FEV{sub 1}, Blutgase) verglichen werden. Methoden: Fuenfzehn Asthmatiker mit bronchialer Hyperreaktivitaet mit FEV{sub 1}-Abfall>20% und PaO{sub 2}-Abfall>10 mmHg nach Provokation (PC20%+), zwoelf Asthmatiker mit FEV{sub 1}-Abfall<20% und PaO{sub 2}-Abfall>10 mmHg nach Provokation (PC20%-) sowie acht Probanden ohne bronchiale Hyperreaktivitaet wurden mit der spirometrisch kontrollierten HRCT bei hohen Fuellungsvolumina vor und nach inhalativer Bronchoprovokation sowie nach Broncholyse untersucht. Es wurden die gesamte und periphere Lungendichte sowie der strukturelle Anteil solider pulmonaler Strukturen bestimmt. Ergebnisse: In allen Gruppen fand sich nach Provokation eine signifikante Abnahme (p<0,0005), nach Broncholyse eine signifikante Zunahme (p<0,0002) der Lungendichte. Die Aenderungen solider Lungenanteile waren nach Provokation und Lyse nicht signifikant unterschiedlich (p>0,05). Bei den hyperreaktiven Patienten fanden sich signifikante PaO{sub 2}-Abnahmen nach Provokation sowie signifikante PaO{sub 2}-Steigerungen nach Lyse (p<0,05). In der Gruppe PC20%+ wurde nach Provokatio ein mittlerer FEV{sub 1}-Abfall von 27,8% beobachtet, in den anderen Gruppen war dieser <20%. Es wurden keine signifikanten Korrelationen zwischen radiologischen und funktionellen Lungentestergebnissen asthmatischer Patienten und Probanden beobachtet. Die bei gesunden Probanden mit der

  1. Interferon-gamma deficiency modifies the motor and co-morbid behavioral pathology and neurochemical changes provoked by the pesticide paraquat.

    Science.gov (United States)

    Litteljohn, D; Mangano, E; Shukla, N; Hayley, S

    2009-12-29

    In addition to nigrostriatal pathology and corresponding motor disturbances, Parkinson's disease (PD) is often characterized by co-morbid neuropsychiatric symptoms, most notably anxiety and depression. Separate lines of evidence indicate that inflammatory processes associated with microglial activation and cytokine release may be fundamental to the progression of both PD and its co-morbid psychiatric pathology. Accordingly, we assessed the contribution of the pro-inflammatory cytokine, interferon-gamma (IFN-gamma), to a range of PD-like pathology provoked by the ecologically relevant herbicide and dopamine (DA) toxin, paraquat. To this end, paraquat provoked overt motor impairment (reduced home-cage activity and impaired vertical climbing) and signs of anxiety-like behavior (reduced open field exploration) in wild-type but not IFN-gamma-deficient mice. Correspondingly, paraquat promoted somewhat divergent variations in neurochemical activity among wild-type and IFN-gamma null mice at brain sites important for both motor (striatum) and co-morbid affective pathologies (dorsal hippocampus, medial prefrontal cortex, and locus coeruleus). Specifically, the herbicide provoked a dosing regimen-dependent reduction in striatal DA levels that was prevented by IFN-gamma deficiency. In addition, the herbicide influenced serotonergic and noradrenergic activity within the dorsal hippocampus and medial prefrontal cortex; and elevated noradrenergic activity within the locus coeruleus. Although genetic ablation of IFN-gamma had relatively few effects on monoamine variations within the locus coeruleus and prefrontal cortex, loss of the pro-inflammatory cytokine did normalize the paraquat-induced noradrenergic alterations within the hippocampus. These findings further elucidate the functional implications of paraquat intoxication and suggest an important role for IFN-gamma in the striatal and motor pathology, as well as the co-morbid behavioral and hippocampal changes induced by

  2. Nitrogen doping on NiO by reactive magnetron sputtering: A new pathway to dynamically tune the optical and electrical properties

    Energy Technology Data Exchange (ETDEWEB)

    Keraudy, Julien, E-mail: julien.keraudy@liu.se [Institut de Recherche Technologique (IRT), Chemin du Chaffault, 44340, Bouguenais (France); Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP32229, 44322, Nantes Cedex 3 (France); Plasma & Coatings Physics Division, IFM Materials Physics, Linköping University, Linköping, SE 581-83 (Sweden); Ferrec, Axel; Richard-Plouet, Mireille; Hamon, Jonathan; Goullet, Antoine; Jouan, Pierre-Yves [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP32229, 44322, Nantes Cedex 3 (France)

    2017-07-01

    Highlights: • Nitrogen doping into NiO lattice (4 at.%) is achieved by only monitoring the N{sub 2}/O{sub 2} gas ratio in the plasma. • The replacement of O by N leads to a narrowing of the optical band-gap energy from 3.6 to 2.3 eV. • The origin of the narrowing is explained by the presence of an intermediate band and the introduction of occupied N 2p states. • Electrical conductivity of NiO:N samples depends on the amount of nickel vacancies and the nitrogen doping. - Abstract: N-doped nickel oxide (NiO:N) thin films were deposited on glass and silicon substrates by reactive DC magnetron sputtering in Ar/O{sub 2}/N{sub 2} gas atmosphere with a series of N{sub 2}/O{sub 2} gas ratio ranging from 0 to 80%. X-ray diffraction measurements have revealed that the films are constituted of Ni{sub 1-x}O grains and showed enhanced polycrystalline features with increasing N-doping concentration. For the first time, we report here that N-doping in the Ni-deficient NiO (Ni{sub 1-x}O) film leads to a band-gap narrowing from 3.6 to 2.3 eV. X-ray photoelectron spectroscopy (XPS) measurements proved that up to 4 atomic percent (at.%) nitrogen can be incorporated at least at the surface of the NiO:N samples. In addition, XPS valence band spectra and UV–vis transmission measurements have demonstrated that the band-gap narrowing may originates from the contribution of an intermediate band (IB) ∼2.4 eV just above the valence band maximum and the up-shifting of the valence band edge (∼0.3 eV) due to the introduction of occupied N 2p states. Local I–V measurements, carried out by conductive AFM (C-AFM), have revealed that the extrinsic doping of N atoms within the oxide can be a good way to precisely control the electrical conductivity of such p-type materials.

  3. Relationship between nongenital tender point tenderness and intravaginal muscle pain intensity: ratings in women with provoked vestibulodynia and implications for treatment.

    Science.gov (United States)

    Phillips, Nancy; Brown, Candace; Bachmann, Gloria; Wan, Jim; Wood, Ronald; Ulrich, Dagny; Bachour, Candi; Foster, David

    2016-12-01

    Vulvodynia is a chronic vulvar pain disorder and fibromyalgia is a chronic widespread musculoskeletal pain disorder, both of unknown etiology. Association of these conditions is well documented. Intravaginal algometer measurement of tenderness to pressure applied to the pelvic floor muscles helps define vulvodynia associated with musculoskeletal factors. Women with both vulvodynia and fibromyalgia might have increased pelvic muscle pain compared to women with vulvodynia alone, defining the possible link of these 2 conditions. We sought to: (1) correlate pain intensity during the nongenital tender point tenderness examination to pain intensity with the vaginal algometer in women with provoked vestibulodynia, and (2) determine whether subjects with provoked vestibulodynia and fibromyalgia had higher pain intensity scores with the vaginal algometer than those without fibromyalgia. In all, 92 subjects referred for vulvar pain were confirmed to have provoked vestibulodynia using the cotton swab test. A diagnosis of fibromyalgia was made if pain was present (numeric rating scale >1) in at least 11 sites of the 18-point nongenital tender point tenderness exam. Vaginal pain sensitivity was measured using an intravaginal pressure algometer, where 0.1, 0.3, and 0.5 kg/cm(2) forces were applied digitally in random assignment by force and location to the right and left iliococcygeus muscle regions and the posterior vaginal wall. Both tender point tenderness and algometer pain intensity were reported on a 0 (no pain) to 10 (worse pain) numeric rating scale. Correlations were computed between the composite pain intensity (total of rating scale from each pressure threshold at specified site) of nongenital and those of iliococcygeus regions and the posterior vaginal wall. Independent t tests were used to determine differences in iliococcygeus regions and the posterior vaginal algometer pain ratings and presence or absence of fibromyalgia. The significance level was at P palpation

  4. Does the solid-liquid crystal phase transition provoke the spin-state change in spin-crossover metallomesogens?

    Science.gov (United States)

    Seredyuk, M; Gaspar, A B; Ksenofontov, V; Galyametdinov, Y; Kusz, J; Gütlich, P

    2008-01-30

    crossover behavior at T(1/2) centered around 140 K. The thermal spin transition is accompanied by a pronounced change of color from dark red (LS) to orange (HS). The light-induced excited spin state trapping (LIESST) effect has been investigated in compounds C(6)-2, C(12)-2 and C(18)-2. The T(1/2)LIESST is 56 K (C(6)-2), 48 K (C(16)-2), and 56 K (C(18)-2). On the basis of differential scanning calorimetry, optical polarizing microscopy, and X-ray diffraction findings for C(18)-1, C(12)-2, and C(18)-2 at high temperature a smectic mesophase SX has been identified with layered structures similar to C(6)-1 and C(6)-2. The compounds [Fe(C(n)-trenH)](Cl)2 x sH2O (n = 16 (C(16)-3, s = 3.5, C(16)-4, s = 0.5, C(16)-5, s = 0), 18 (C(18)-3, s = 3.5, C(18)-4, s = 0.5, C(18)-5, s = 0), 20 (C(20)-3, s = 3.5, C(20)-4, s = 0.5, C(20)-5, s = 0)) and [Fe(C18-tren)](F)2 x sH2O (C(18)-6, s = 3.5, C(18)-7, s = 0) show a very particular spin-state change, while [Fe(C18-tren)](Br)2 x 3H2O (C(18)-8) together with [Fe(C18-tren)](I)2 (C(18)-9) are in the LS state (10-400 K) and present mesomorphic behavior like that observed for the complexes C(18)-1, C(12)-2, and C(18)-2. In compounds C(n)-3 50% of the Fe(II) ions undergo spin-state change at T(1/2) = 375 K induced by releasing water, and in partially dehydrated compounds (s = 0.5) the Cr-->SA phase transition occurs at 287 K (C(16)-4), 301 K (C(18)-4) and 330 K (C(20)-4). For the fully dehydrated materials C(n)-5 50% of the Fe(II) ions are in the HS state and show paramagnetic behavior between 10 and 400 K. In the partially dehydrated C(n)-4 the spin transition is induced by the change of the aggregate state of matter (solidliquid crystal). For compound C(18)-6 the full dehydration to C(18)-7 provokes the spin-state change of nearly 50% of the Fe(II) ions. The compounds C(n)-3 and C(18)-6 are dark purple in the LS state and become light purple-brown when 50% of the Fe(II) atoms are in the HS state.

  5. Dynamic Management of NOx and SO2 Emissions in the Texas and Mid-Atlantic Electric Power Systems and Implications for Air Quality.

    Science.gov (United States)

    McDonald-Buller, Elena; Kimura, Yosuke; Craig, Michael; McGaughey, Gary; Allen, David; Webster, Mort

    2016-02-02

    Cap and trade programs have historically been designed to achieve annual or seasonal reductions in emissions of nitrogen oxides and sulfur dioxide from power plants. Emissions reductions may not be temporally coincident with meteorological conditions conducive to the formation of peak ozone and fine particulate matter concentrations. Integrated power system and air quality modeling methods were developed to evaluate time-differentiated emissions price signals on high ozone days in the Mid-Atlantic portion of the Pennsylvania-New Jersey-Maryland (PJM) Interconnection and Electric Reliability Council of Texas (ERCOT) grids. Sufficient flexibility exists in the two grids with marked differences in demand and fuel generation mix to accommodate time-differentiated emissions pricing alone or in combination with a season-wide program. System-wide emissions reductions and production costs from time-differentiated pricing are shown to be competitive with those of a season-wide program on high ozone days and would be more cost-effective if the primary policy goal was to target emissions reductions on these days. Time-differentiated pricing layered as a complement to the Cross-State Air Pollution Rule had particularly pronounced benefits for the Mid-Atlantic PJM system that relies heavily on coal-fired generation. Time-differentiated pricing aimed at reducing ozone concentrations had particulate matter reduction co-benefits, but if particulate matter reductions are the primary objective, other approaches to time-differentiated pricing may lead to greater benefits.

  6. Evolutionary Dynamics of 5S rDNA and Recurrent Association of Transposable Elements in Electric Fish of the Family Gymnotidae (Gymnotiformes): The Case of Gymnotus mamiraua.

    Science.gov (United States)

    da Silva, Maelin; Barbosa, Patricia; Artoni, Roberto F; Feldberg, Eliana

    2016-01-01

    Gymnotidae is a family of electric fish endemic to the Neotropics consisting of 2 genera: Electrophorus and Gymnotus. The genus Gymnotus is widely distributed and is found in all of the major Brazilian river systems. Physical and molecular mapping data for the ribosomal DNA (rDNA) in this genus are still scarce, with its chromosomal location known in only 11 species. As other species of Gymnotus with 2n = 54 chromosomes from the Paraná-Paraguay basin, G. mamiraua was found to have a large number of 5S rDNA sites. Isolation and cloning of the 5S rDNA sequences from G. mamiraua identified a fragment of a transposable element similar to the Tc1/mariner transposon associated with a non-transcribed spacer. Double fluorescence in situ hybridization analysis of this element and the 5S rDNA showed that they were colocalized on several chromosomes, in addition to acting as nonsyntenic markers on others. Our data show the association between these sequences and suggest that the Tc1 retrotransposon may be the agent that drives the spread of these 5S rDNA-like sequences in the G. mamiraua genome. © 2016 S. Karger AG, Basel.

  7. A comparative study of the vibrational corrections for the dynamic electric properties of the LiF molecule using numerical and perturbation methods

    Science.gov (United States)

    Pessoa, Renato; Castro, Marcos A.; Amaral, Orlando A. V.; Fonseca, Tertius L.

    2005-08-01

    In this work we report results of CPHF calculations, including vibrational corrections, for the dynamic polarizability and first hyperpolarizability of the LiF molecule. Vibrational corrections were computed through the Numerov-Cooley and perturbation-theoretic methods. Comparison between the results obtained using both methods shows that first-order perturbation-theoretic provides a good approximation for the zpva contribution. The double-harmonic-oscillator approximation is reliable for the pv contributions of αzz, βxxz and βzxx, while [ μα] 0 + [ μ3] I is a good approximation for βzzz. CCSD(T) results obtained for the pv contribution show that the electron correlation effects are small for the polarizability but significant for the first hyperpolarizability.

  8. Electric fields and electrical insulation

    DEFF Research Database (Denmark)

    McAllister, Iain Wilson

    2002-01-01

    The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface...... roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  9. Lower Hybrid Wave Electric Field Vector Measurements Using Non-Perturbative Dynamic Stark Effect Optical Spectroscopy on Alcator C-Mod

    Science.gov (United States)

    Martin, E. H.

    2017-10-01

    Plasma-wave interactions near the lower hybrid (LH) wave launcher can have a major impact on driven LH current, especially in the high-density regime. To identify the relevant physics responsible for this interaction a correlated effort of experimental measurements and simulations of the LH wave electric field vector, ELH, were carried out on Alcator C-Mod using the SELHF (Stark Effect Lower Hybrid Field) diagnostic and COMSOL modeling. For a range of plasma parameters observations show that: 1) The polarization ELH resides primarily in the radial-poloidal plane and becomes increasingly poloidal for locations away and to the top of the LH launcher. 2) Saturation of the radial component of ELH is observed at an LH power density of approximately 12 MW/m2. 3) Reflectometry phase fluctuations were found to be correlated with |ELH|. These results suggest that the LH resonance cone and power spectrum may be substantially modified near the LH launcher in the high-density regime from the expected radial polarization and square root scaling of the magnitude with LH power. Simulation of the experimental data was carried out through development of a synthetic diagnostic using a full wave cold plasma COMSOL model. Density fluctuations and reflectometry measured density profiles were incorporated. Without density fluctuations, the synthetic ELH signal is dominantly in the radial direction and scales with the square root of LH power, as expected. Increasing density fluctuations in the model can cause the magnitude of ELH to decrease substantially and greatly vary the direction of ELH. The observations and results outlined above will be presented in detail and the applicability of density fluctuations as a mechanism behind the behavior of ELH will be discussed. Funded by the DOE OFES (DE-AC05-00OR22725 and DE-FC02-99ER54512).

  10. Electric fields and quantum wormholes

    NARCIS (Netherlands)

    Engelhardt, D.; Freivogel, B.; Iqbal, N.

    2015-01-01

    Electric fields can thread a classical Einstein-Rosen bridge. Maldacena and Susskind have recently suggested that in a theory of dynamical gravity the entanglement of ordinary perturbative quanta should be viewed as creating a quantum version of an Einstein-Rosen bridge between the particles, or a

  11. Visual Electricity Demonstrator

    Science.gov (United States)

    Lincoln, James

    2017-09-01

    The Visual Electricity Demonstrator (VED) is a linear diode array that serves as a dynamic alternative to an ammeter. A string of 48 red light-emitting diodes (LEDs) blink one after another to create the illusion of a moving current. Having the current represented visually builds an intuitive and qualitative understanding about what is happening in a circuit. In this article, I describe several activities for this device and explain how using this technology in the classroom can enhance the understanding and appreciation of physics.

  12. Electricity unplugged

    Science.gov (United States)

    Karalis, Aristeidis

    2009-02-01

    The judge was driving back late one cold winter night. Entering the garage, the battery-charging indicator in his wirelessly powered electric car came on. "Home at last," crossed his mind. He swiped his personal smartcard on the front-door detector to be let in. He heard a "charging" beep from his mobile phone. The blinking cursor on the half-finished e-mail on the laptop had been waiting all day on the side table. He picked the computer up and walked towards his desk. "Good evening, your honour. Your wirelessly heated robe," said the butler-robot as it approached from the kitchen. Putting on the electric garment, he sat on the medical desk chair. His artificial heart was now beating faster.

  13. Gas-dynamic perturbations in an electric-discharge repetitively pulsed DF laser and the role of He in their suppression

    Science.gov (United States)

    Evdokimov, P. A.; Sokolov, D. V.

    2015-11-01

    The gas-dynamic perturbations in a repetitively pulsed DF laser are studied using a Michelson interferometer. Based on the analysis of experimental data obtained in two experimental sets (working medium without buffer gas and with up to 90% of He), it is concluded that such phenomena as isentropic expansion of a thermal plug, gas heating by shock waves and resonance acoustic waves do not considerably decrease the upper limit of the pulse repetition rate below a value determined by the time of the thermal plug flush out of the discharge gap. It is suggested that this decrease for a DF laser with the SF6 - D2 working mixture is caused by the development of overheat instability due to an increased energy deposition into the near-electrode regions and to the formation of electrode shock waves. Addition of He to the active media of the DF laser changes the discharge structure and improves its homogeneity over the discharge gape cross section, thus eliminating the reason for the development of this instability. A signification dilution of the active medium of a DF laser with helium up to the atmospheric pressure allowed us to achieve the limiting discharge initiation frequencies with the active medium replacement ratio K ~ 1.

  14. Electric Car

    Science.gov (United States)

    1977-01-01

    NASA's Lewis Research Center undertook research toward a practical, economical battery with higher energy density. Borrowing from space satellite battery technology, Lewis came up with a nickel-zinc battery that promises longer life and twice the range of the lead-acid counterpart. Lewis researchers fabricated a prototype battery and installed it in an Otis P-500 electric utility van, using only the battery space already available and allowing battery weight equal to that of the va's conventional lead-acid battery

  15. Dynamical critical scaling of electric field fluctuations in the greater cusp and magnetotail implied by HF radar observations of F-region Doppler velocity

    Directory of Open Access Journals (Sweden)

    M. L. Parkinson

    2006-03-01

    Full Text Available Akasofu's solar wind ε parameter describes the coupling of solar wind energy to the magnetosphere and ionosphere. Analysis of fluctuations in ε using model independent scaling techniques including the peaks of probability density functions (PDFs and generalised structure function (GSF analysis show the fluctuations were self-affine (mono-fractal, single exponent scaling over 9 octaves of time scale from ~46 s to ~9.1 h. However, the peak scaling exponent α0 was a function of the fluctuation bin size, so caution is required when comparing the exponents for different data sets sampled in different ways. The same generic scaling techniques revealed the organisation and functional form of concurrent fluctuations in azimuthal magnetospheric electric fields implied by SuperDARN HF radar measurements of line-of-sight Doppler velocity, vLOS, made in the high-latitude austral ionosphere. The PDFs of vLOS fluctuation were calculated for time scales between 1 min and 256 min, and were sorted into noon sector results obtained with the Halley radar, and midnight sector results obtained with the TIGER radar. The PDFs were further sorted according to the orientation of the interplanetary magnetic field, as well as ionospheric regions of high and low Doppler spectral width. High spectral widths tend to occur at higher latitude, mostly on open field lines but also on closed field lines just equatorward of the open-closed boundary, whereas low spectral widths are concentrated on closed field lines deeper inside the magnetosphere. The vLOS fluctuations were most self-affine (i.e. like the solar wind ε parameter on the high spectral width field lines in the noon sector ionosphere (i.e. the greater cusp, but suggested multi-fractal behaviour on closed field lines in the midnight sector (i.e. the central plasma sheet. Long tails in the PDFs imply that "microbursts" in ionospheric convection

  16. Everyday life for users of electric wheelchairs

    DEFF Research Database (Denmark)

    Rossen, Camilla Blach; Sørensen, Bodil; Jochumsen, Bente Würtz

    2012-01-01

    The aim of this paper is to explore how users of electric wheelchairs experience their everyday life and how their electric wheelchairs influence their daily occupation. Occupation is defined as a personalized dynamic interaction between person, task and environment, and implies the value...

  17. On the Possibility of the Jerk Derivative in Electrical Circuits

    National Research Council Canada - National Science Library

    J. F. Gómez-Aguilar; J. Rosales-García; R. F. Escobar-Jiménez; M. G. López-López; V. M. Alvarado-Martínez; V. H. Olivares-Peregrino

    2016-01-01

    .... Some mechanical and acoustic systems can be interpreted as jerky dynamics. In this paper we show that the jerk dynamics are naturally obtained for electrical circuits using the fractional calculus approach with order γ...

  18. Lightning activity and radar observations of the multicell thunderstorm system passing over Swider Observatory (Poland) on 19 July 2015 and its dynamic and electric charge structure obtained from the WRF_ELEC model

    Science.gov (United States)

    Kubicki, Marek; Konarski, Jerzy; Gajda, Wojciech; Barański, Piotr; Guzikowski, Jakub; Kryza, Maciej

    2017-04-01

    In this work we present preliminary results on the thunderstorm event at IG PAS Swider Geophysical Observatory (52.12°N, 21.25°E, geomagnetic latitude 50.5°N, near Warsaw, Poland) on 19 July 2015. The storm was caused by the abrasion of the warm front that stretched almost latitudinaly and cold front moving from the west to the east. Warm continental-tropical arrived at southern and eastern part of the country and the rest was covered by cool polar-maritime airmass. The storm had the squall-line character of approximately 100 km length and consisted of several cells, and the height of the cumulonimbus (Cb) cloud base was 1 km and top was 14 km, as inferred from the analysis of CAPPI (Constant Altitude Plan Position Indicator), CMAX (Column Maximum Display), MLVCUT (Multiple-Line Vertical Cut) radar map products from POLRAD observations at Institute of Meteorology and Water Management - National Research Institute (IMWM-NRI), Legionowo station. In our paper we have discussed the obtained results of the post-time analysis of lightning activity and radar observations of the extended multicells thunderstorm system passing over IG PAS Swider Geophysical Observatory, on 19 July 2015 together with its dynamic and electric charge structure obtained from the WRF_ELEC model. We have used the archive data from the Polish National Lightning Location and Detection System PERUN (provided by IMWM-NRI) together with radar data obtained from the Doppler meteorological radar METEOR 1500C at Legionowo. Additionally, during the approach, passing over and moving away phase of the thunderstorm system, we have gathered the simultaneous and continuous recordings of E-field, the electric conductivity of air and the independent supplementary reference lightning detections delivered by the Swider measuring station of the Local Lightning Detection Network (LLDN) operated in Warsaw region. These data have given us a new possibility to acquire many valuable information about the

  19. Electrical anharmonicity and dampings contributions to Cl-H → stretching band in gaseous (CH3)2O…HCl complex: Quantum dynamic study and prediction of the temperature effects

    Science.gov (United States)

    Rekik, Najeh; Alshammari, Majid F.

    2017-06-01

    In a previous work (Rekik et al., 2017), we demonstrated the ability of a simple anharmonic model of the dipole moment function of the X-H stretching band to explain a set of spectroscopic features of hydrogen bonding formation. Within the context of this model, we have shown that the origins of the broadening of the X - H → stretching band is attributed to large terms in the expansion of the autocorrelation functions due to the electrical anharmonicity. However, the question remained as to the ability of this model to treat the more complex situation in which we take into account the relaxation mechanisms that look at the effect of the surroundings and thereby gives rise to signatures of the medium to the X - H → stretching band lineshapes. Thus, in the present study, we investigated this situation by envisaging that the direct relaxation mechanism is due to the coupling between the fluctuating local electric field and the dipole moment of the complex as rationalized by Rosh and Ratner and the indirect damping resulting from the interaction of the X - H → stretch with its environment via the H-bond bridge mode. Theoretical experiments show that mixing of all these effects results in a speard and complicated structure. Using an ensemble of physically sound parameters as input into this approach, we have captured the main features in the experimental Cl - H → band in gaseous (CH3)2O…HCl complex and shown that the direct relaxation entrains a broadening of the spectra and is capable of qualitatively capturing the main features in the experimental spectra and quantitatively capturing the characteristic time scale of the vibrational dynamics of the Cl - H → stretching band. Furthermore, due to the decent agreement obtained between the theoretical and experimental line shapes at 226 K, the evolution of the IR spectra with the varaiation of temperature is proposed. The findings gained herein underscore the utility of combining simultaneously the effects of

  20. Photoluminescence under high-electric field of PbS quantum dots

    Directory of Open Access Journals (Sweden)

    B. Ullrich

    2012-12-01

    Full Text Available The effect of a laterally applied electric field (≤10 kV/cm on the photoluminescence of colloidal PbS quantum dots (diameter of 2.7 nm on glass was studied. The field provoked a blueshift of the emission peak, a reduction of the luminescent intensity, and caused an increase in the full width at half maximum of the emission spectrum. Upon comparison with the photoluminescence of p-type GaAs exhibits the uniqueness of quantum dot based electric emission control with respect to bulk materials.