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Sample records for brain-controlled functional electrical

  1. Toward the restoration of hand use to a paralyzed monkey: brain-controlled functional electrical stimulation of forearm muscles.

    Directory of Open Access Journals (Sweden)

    Eric A Pohlmeyer

    Full Text Available Loss of hand use is considered by many spinal cord injury survivors to be the most devastating consequence of their injury. Functional electrical stimulation (FES of forearm and hand muscles has been used to provide basic, voluntary hand grasp to hundreds of human patients. Current approaches typically grade pre-programmed patterns of muscle activation using simple control signals, such as those derived from residual movement or muscle activity. However, the use of such fixed stimulation patterns limits hand function to the few tasks programmed into the controller. In contrast, we are developing a system that uses neural signals recorded from a multi-electrode array implanted in the motor cortex; this system has the potential to provide independent control of multiple muscles over a broad range of functional tasks. Two monkeys were able to use this cortically controlled FES system to control the contraction of four forearm muscles despite temporary limb paralysis. The amount of wrist force the monkeys were able to produce in a one-dimensional force tracking task was significantly increased. Furthermore, the monkeys were able to control the magnitude and time course of the force with sufficient accuracy to track visually displayed force targets at speeds reduced by only one-third to one-half of normal. Although these results were achieved by controlling only four muscles, there is no fundamental reason why the same methods could not be scaled up to control a larger number of muscles. We believe these results provide an important proof of concept that brain-controlled FES prostheses could ultimately be of great benefit to paralyzed patients with injuries in the mid-cervical spinal cord.

  2. Brain-Controlled Neuromuscular Stimulation to Drive Neural Plasticity and Functional Recovery

    Science.gov (United States)

    Ethier, C.; Gallego, J.A.; Miller, L.E.

    2015-01-01

    There is mounting evidence that appropriately timed neuromuscular stimulation can induce neural plasticity and generate functional recovery from motor disorders. This review addresses the idea that coordinating stimulation with a patient’s voluntary effort might further enhance neurorehabilitation. Studies in cell cultures and behaving animals have delineated the rules underlying neural plasticity when single neurons are used as triggers. However, the rules governing more complex stimuli and larger networks are less well understood. We argue that functional recovery might be optimized if stimulation were modulated by a brain machine interface, to matched the details of the patient’s voluntary intent. The potential of this novel approach highlights the need for a better understanding of the complex rules underlying this form of plasticity. PMID:25827275

  3. Electricity economics. Production functions with electricity

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhaoguang [State Grid Energy Research Institute, Beijing (China); Hu, Zheng [Delaware Univ., Newark, DE (United States)

    2013-07-01

    The first book studies on the economics of electricity consumption. Compares the sector production functions with electricity and the commercial production functions with electricity. Introduces the global E-GDP function, the European E-GDP function and 12 national E-GDP functions. Presents the gene characters of EAI production functions and E-GDP functions for USA to see why USA's economy is entering an up-industrialization period. Discusses China's economic growth by production functions with electricity. Electricity Economics: Production Functions with Electricity studies the production output from analyzing patterns of electricity consumption. Since electricity data can be used to measure scenarios of economic performance due to its accuracy and reliability, it could therefore also be used to help scholars explore new research frontiers that directly and indirectly benefits human society. Our research initially explores a similar pattern to substitute the Cobb-Douglas function with the production function with electricity to track and forecast economic activities. The book systematically introduces the theoretical frameworks and mathematical models of economics from the perspective of electricity consumption. The E-GDP functions are presented for case studies of more than 20 developed and developing countries. These functions also demonstrate substantial similarities between human DNA and production functions with electricity in terms of four major characteristics, namely replication, mutation, uniqueness, and evolution. Furthermore, the book includes extensive data and case studies on the U.S., China, Japan, etc. It is intended for scientists, engineers, financial professionals, policy makers, consultants, and anyone else with a desire to study electricity economics as well as related applications.

  4. Electricity price forecasting through transfer function models

    International Nuclear Information System (INIS)

    Forecasting electricity prices in present day competitive electricity markets is a must for both producers and consumers because both need price estimates to develop their respective market bidding strategies. This paper proposes a transfer function model to predict electricity prices based on both past electricity prices and demands, and discuss the rationale to build it. The importance of electricity demand information is assessed. Appropriate metrics to appraise prediction quality are identified and used. Realistic and extensive simulations based on data from the PJM Interconnection for year 2003 are conducted. The proposed model is compared with naive and other techniques. Journal of the Operational Research Society (2006) 57, 350-356.doi:10.1057/palgrave.jors.2601995; published online 18 May 2005. (author)

  5. Electricity price forecasting through transfer function models

    Energy Technology Data Exchange (ETDEWEB)

    Nogales, F.J. [Universidad Carlos II, Madrid (Spain); Conejo, A.J. [Universidad de Castilla, Ciudad Real (Spain)

    2006-04-15

    Forecasting electricity prices in present day competitive electricity markets is a must for both producers and consumers because both need price estimates to develop their respective market bidding strategies. This paper proposes a transfer function model to predict electricity prices based on both past electricity prices and demands, and discuss the rationale to build it. The importance of electricity demand information is assessed. Appropriate metrics to appraise prediction quality are identified and used. Realistic and extensive simulations based on data from the PJM Interconnection for year 2003 are conducted. The proposed model is compared with naive and other techniques. Journal of the Operational Research Society (2006) 57, 350-356.doi:10.1057/palgrave.jors.2601995; published online 18 May 2005. (author)

  6. Functional electrical stimulation with surface electrodes

    Directory of Open Access Journals (Sweden)

    Bajd Tadej

    2008-01-01

    Full Text Available The review investigates the objective evidences of benefits derived from surface functional electrical stimulation (FES of lower and upper extremities for people after incomplete spinal cord injury (SCI and stroke. FES can offer noticeable benefits in walking ability. It can be efficiently combined with treadmill and body weight support. Voluntary muscle strength and endurance gain can be achieved through FES assisted gait training together with increased gait velocity in absence of electrical stimulator. Cyclic FES, FES augmented by biofeedback, and FES used in various daily activities can result in substantial improvements of the voluntary control of upper extremities.

  7. Technical Rebuilding of Movement Function Using Functional Electrical Stimulation

    Science.gov (United States)

    Gföhler, Margit

    To rebuild lost movement functions, neuroprostheses based on functional electrical stimulation (FES) artificially activate skeletal muscles in corresponding sequences, using both residual body functions and artificial signals for control. Besides the functional gain, FES training also brings physiological and psychological benefits for spinal cord-injured subjects. In this chapter, current stimulation technology and the main components of FES-based neuroprostheses including enhanced control systems are presented. Technology and application of FES cycling and rowing, both approaches that enable spinal cord-injured subjects to participate in mainstream activities and improve their health and fitness by exercising like able-bodied subjects, are discussed in detail, and an overview of neuroprostheses that aim at restoring movement functions for daily life as walking or grasping is given.

  8. Artifacts of Functional Electrical Stimulation on Electromyograph

    Institute of Scientific and Technical Information of China (English)

    DUAN Ren-quan; ZHANG Ding-guo

    2014-01-01

    The purpose of this study is to investigate different factors of the artifact in surface electromyography (EMG) signal caused by functional electrical stimulation (FES). The factors investigated include the size of stimulation electrode pads, the amplitude, frequency, and pulse width of the stimulation waveform and the detecting electrode points. We calculate the root mean square (RMS) of EMG signal to analyze the effect of these factors on the M-wave properties. The results indicate that the M-wave mainly depends on the stimulation amplitude and the distribution of detecting electrodes, but not on the other factors. This study can assist the reduction of artifact and the selection of detecting electrode points.

  9. Functional Electrical Stimulation in Children and Adolescents with Cerebral Palsy

    Science.gov (United States)

    van der Linden, Marietta

    2012-01-01

    In this article, the author talks about functional electrical stimulation in children and adolescents with cerebral palsy. Functional electrical stimulation (FES) is defined as the electrical stimulation of muscles that have impaired motor control, in order to produce a contraction to obtain functionally useful movement. It was first proposed in…

  10. Functional Carbon Nanotubes for Electrical Conductors

    Science.gov (United States)

    Schauerman, Christopher Mark

    Carbon nanotube (CNT) conductors are an enabling technology for advancing the efficacy of sustainable energy systems. In parallel, proactive consideration for each of the phases in the material life cycle can enhance device performance while minimizing unwanted impacts. Increasing the yield of CNTs through advances in synthesis will help reduce the electricity, chemicals, and costs associated with their production. Modifications to the nanoscale morphology (alignment, bundling, density and lower contact resistances) are needed to improve the CNT material properties to meet or exceed those of conventional metallic conductors. Also, a robust evaluation of methods for contacting carbon-based wires is needed when interfacing with metallic contacts. Finally, it's important to begin looking at upstream options for proper treatment of waste streams containing CNT conductors when they reach the end of their useable life. Therefore, the subject of this dissertation focuses on the development of functional CNT conductors and considers approaches to improve each phase of their life cycle. Specifically, progress towards using more efficient catalysts in the laser vaporization process has led to a 50% increase in SWCNT yield and simplified the purification procedure. The use of chemical dopants such as KAuCl4 has increased the electrical conductivity up to 1x10 6 S/m which is over an order of magnitude higher than the pre-doping baseline value. Alternatively, chlorosulfonic acid was used to disperse high weight loadings of SWCNTs and modify the nanoscale morphology through the use of selective coagulation and mechanical extrusions of binder free SWCNT wires. The highly dense and aligned wires have electrical conductivities as high as 4.9x106 S/m and are in agreement with the highest CNT conductivities reported. The ability to contact bulk CNT conductors through ultrasonic welding was demonstrated for the first time and exhibit low carbon-copper contact resistances of 4.3 mO-cm2

  11. Wireless distributed functional electrical stimulation system

    Directory of Open Access Journals (Sweden)

    Jovičić Nenad S

    2012-08-01

    Full Text Available Abstract Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers. One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  12. Functional electrical stimulation on paraplegic patients

    Directory of Open Access Journals (Sweden)

    Helmut Kern

    2014-07-01

    Full Text Available We report on clinical and physiological effects of 8 months Functional Electrical Stimulation (FES of quadriceps femoris muscle on 16 paraplegic patients. Each patient had muscle biopsies, CT-muscle diameter measurements, knee extension strength testing carried out before and after 8 months FES training. Skin perfusion was documented through infrared telethermography and xenon clearance, muscle perfusion was recorded through thallium scintigraphy. After 8 months FES training baseline skin perfusion showed 86 % increase, muscle perfusion was augmented by 87 %. Muscle fiber diameters showed an average increase of 59 % after 8 months FES training. Muscles in patients with spastic paresis as well as in patients with denervation showed an increase in aerob and anaerob muscle enzymes up to the normal range. Even without axonal neurotropic substances FES was able to demonstrate fiberhypertrophy, enzyme adaptation and intracellular structural benefits in denervated muscles. The increment in muscle area as visible on CT-scans of quadriceps femoris was 30 % in spastic paraplegia and 10 % in denervated patients respectively. FES induced changes were less in areas not directly underneath the surface electrodes. We strongly recommend the use of Kern`s current for FES in denervated muscles to induce tetanic muscle contractions as we formed a very critical opinion of conventional exponential current. In patients with conus-cauda-lesions FES must be integrated into modern rehabilitation to prevent extreme muscle degeneration and decubital ulcers. Using FES we are able to improve metabolism and induce positive trophic changes in our patients lower extremities. In spastic paraplegics the functions „rising and walking“ achieved through FES are much better training than FES ergometers. Larger muscle masses are activated and an increased heart rate is measured, therefore the impact on cardiovascular fitness and metabolism is much greater. This effectively

  13. Plasmonic functionalities based on detuned electrical dipoles

    DEFF Research Database (Denmark)

    Pors, Anders Lambertus; Nielsen, Michael Grøndahl; Bozhevolnyi, Sergey I.

    2013-01-01

    We introduce and demonstrate the concept of detuned electrical dipoles (DED) that originates from the plasmonic realization of the dressed-state picture of electromagnetically induced transparency in atomic physics. Numerically and experimentally analyzing DED metamaterials consisting of unit cells...

  14. Electromyographic evaluation of functional electrical stimulation to injured oculomotor nerve

    Institute of Scientific and Technical Information of China (English)

    Min Yang; Shiting Li; Youqiang Meng; Ningxi Zhu; Xuhui Wang; Liang Wan; Wenchuan Zhang; Jun Zhong; Shugan Zhu; Massimiliano Visocchi

    2011-01-01

    Functional electrical stimulation delivered early after injury to the proximal nerve stump has been proposed as a therapeutic approach for enhancing the speed and specificity of axonal regeneration following nerve injury. In this study, the injured oculomotor nerve was stimulated functionally by an implantable electrode. Electromyographic monitoring of the motor unit potential of the inferior oblique muscle was conducted for 12 weeks in two injury groups, one with and one without electric stimulation. The results revealed that, at 2, 4, 6, 8 weeks after functional electric stimulation of the injured oculomotor nerve, motor unit potentials significantly increased, such that amplitude was longer and spike duration gradually shortened. These findings indicate that the injured oculomotor nerve has the potential for regeneration and repair, but this ability is not sufficient for full functional recovery to occur. Importantly, the current results indicated that recovery and regeneration of the injured oculomotor nerve can be promoted with functional electrical stimulation.

  15. Functional electrical stimulation bicycle ergometry: patient perceptions.

    Science.gov (United States)

    Sipski, M L; Delisa, J A; Schweer, S

    1989-06-01

    Forty-seven patients who had participated in a clinical electrical stimulation ergometry program were administered a questionnaire to determine their perceptions of the therapy. Improved endurance was reported by 62% of paraplegics and 65% of quadriplegics. Sixty-two percent of paraplegics and 56% of quadriplegics reported improved self-image, while 54% of paraplegics and 77% of quadriplegics perceived their appearance was better. Thirty-nine percent of paraplegics and 24% of quadriplegics noted decreased lower extremity edema with training. Six out of nine patients with a previous history of neurogenic pain noted an increase in pain, which caused them to leave the program.

  16. Optimizing electricity consumption: A case of function learning.

    Science.gov (United States)

    Guath, Mona; Millroth, Philip; Juslin, Peter; Elwin, Ebba

    2015-12-01

    A popular way to improve consumers' control over their electricity consumption is by providing outcome feedback on the cost with in-home displays. Research on function learning, however, suggests that outcome feedback may not always be ideal for learning, especially if the feedback signal is noisy. In this study, we relate research on function learning to in-home displays and use a laboratory task simulating a household to investigate the role of outcome feedback and function learning on electricity optimization. Three function training schemes (FTSs) are presented that convey specific properties of the functions that relate the electricity consumption to the utility and cost. In Experiment 1, we compared learning from outcome feedback with 3 FTSs, 1 of which allowed maximization of the utility while keeping the budget, despite no feedback about the total monthly cost. In Experiment 2, we explored the combination of this FTS and outcome feedback. The results suggested that electricity optimization may be facilitated if feedback learning is preceded by a brief period of function training. PMID:26460677

  17. Optimizing electricity consumption: A case of function learning.

    Science.gov (United States)

    Guath, Mona; Millroth, Philip; Juslin, Peter; Elwin, Ebba

    2015-12-01

    A popular way to improve consumers' control over their electricity consumption is by providing outcome feedback on the cost with in-home displays. Research on function learning, however, suggests that outcome feedback may not always be ideal for learning, especially if the feedback signal is noisy. In this study, we relate research on function learning to in-home displays and use a laboratory task simulating a household to investigate the role of outcome feedback and function learning on electricity optimization. Three function training schemes (FTSs) are presented that convey specific properties of the functions that relate the electricity consumption to the utility and cost. In Experiment 1, we compared learning from outcome feedback with 3 FTSs, 1 of which allowed maximization of the utility while keeping the budget, despite no feedback about the total monthly cost. In Experiment 2, we explored the combination of this FTS and outcome feedback. The results suggested that electricity optimization may be facilitated if feedback learning is preceded by a brief period of function training.

  18. Modulation of proprioceptive feedback during functional electrical stimulation

    DEFF Research Database (Denmark)

    Christensen, Mark Schram; Grey, Michael James

    2013-01-01

    Functional electrical stimulation (FES) is sometimes used as a therapeutic modality in motor rehabilitation to augment voluntary motor drive to effect movement that would otherwise not be possible through voluntary activation alone. Effective motor rehabilitation should require that the central n...

  19. Neurocontrol of the inverse dynamics in functional electrical stimulation

    NARCIS (Netherlands)

    Spaanenburg, L; Nijhuis, JAG; Ypma, A; Silva, FL; Principe, JC; Almeida, LB

    1997-01-01

    The rehabilitation of paraplegia can be pursued by functional electrical stimulation (FES) combined with biofeedback This requires control by surface electromyographical (EMG) signals to predict the muscle stimulation patterns while compensating the inherent phase lag. This can be realized by a tapp

  20. Functionally Graded Interfaces: Role and Origin of Internal Electric Field and Modulated Electrical Response.

    Science.gov (United States)

    Maurya, Deepam; Zhou, Yuan; Chen, Bo; Kang, Min-Gyu; Nguyen, Peter; Hudait, Mantu K; Priya, Shashank

    2015-10-14

    We report the tunable electrical response in functionally graded interfaces in lead-free ferroelectric thin films. Multilayer thin film graded heterostructures were synthesized on platinized silicon substrate with oxide layers of varying thickness. Interestingly, the graded heterostructure thin films exhibited shift of the hysteresis loops on electric field and polarization axes depending upon the direction of an applied bias. A diode-like characteristics was observed in current-voltage behavior under forward and reverse bias. This modulated electrical behavior was attributed to the perturbed dynamics of charge carriers under internal bias (self-bias) generated due to the increased skewness of the potential wells. The cyclic sweeping of voltage further demonstrated memristor-like current-voltage behavior in functionally graded heterostructure devices. The presence of an internal bias assisted the generation of photocurrent by facilitating the separation of photogenerated charges. These novel findings provide opportunity to design new circuit components for the next generation of microelectronic device architectures. PMID:26378954

  1. Functional electrical stimulation for incomplete spinal cord injury

    OpenAIRE

    Fazio, Christina

    2014-01-01

    This case report describes the early use of functional electrical stimulation on an individual with an incomplete spinal cord injury to assist with motor recovery and a return to ambulation. A 32-year-old woman sustained a C7 burst fracture after a fall, requiring anterior cervical fixation from C6 to T1 prior to transfer to acute rehabilitation. She presented as a C8 AIS B spinal cord injury, meaning she had some sensory function spared below the level of injury but not motor function. At di...

  2. Brain-Computer Interface Controlled Functional Electrical Stimulation System for Ankle Movement

    Directory of Open Access Journals (Sweden)

    King Christine E

    2011-08-01

    Full Text Available Abstract Background Many neurological conditions, such as stroke, spinal cord injury, and traumatic brain injury, can cause chronic gait function impairment due to foot-drop. Current physiotherapy techniques provide only a limited degree of motor function recovery in these individuals, and therefore novel therapies are needed. Brain-computer interface (BCI is a relatively novel technology with a potential to restore, substitute, or augment lost motor behaviors in patients with neurological injuries. Here, we describe the first successful integration of a noninvasive electroencephalogram (EEG-based BCI with a noninvasive functional electrical stimulation (FES system that enables the direct brain control of foot dorsiflexion in able-bodied individuals. Methods A noninvasive EEG-based BCI system was integrated with a noninvasive FES system for foot dorsiflexion. Subjects underwent computer-cued epochs of repetitive foot dorsiflexion and idling while their EEG signals were recorded and stored for offline analysis. The analysis generated a prediction model that allowed EEG data to be analyzed and classified in real time during online BCI operation. The real-time online performance of the integrated BCI-FES system was tested in a group of five able-bodied subjects who used repetitive foot dorsiflexion to elicit BCI-FES mediated dorsiflexion of the contralateral foot. Results Five able-bodied subjects performed 10 alternations of idling and repetitive foot dorsifiexion to trigger BCI-FES mediated dorsifiexion of the contralateral foot. The epochs of BCI-FES mediated foot dorsifiexion were highly correlated with the epochs of voluntary foot dorsifiexion (correlation coefficient ranged between 0.59 and 0.77 with latencies ranging from 1.4 sec to 3.1 sec. In addition, all subjects achieved a 100% BCI-FES response (no omissions, and one subject had a single false alarm. Conclusions This study suggests that the integration of a noninvasive BCI with a lower

  3. Molecular electric moments calculated by using natural orbital functional theory

    CERN Document Server

    Mitxelena, Ion

    2016-01-01

    The molecular electric dipole, quadrupole and octupole moments of a selected set of 21 spin-compensated molecules are determined employing the extended version of the Piris natural orbital functional 6 (PNOF6), using the triple-$\\zeta$ Gaussian basis set with polarization functions developed by Sadlej, at the experimental geometries. The performance of the PNOF6 is established by carrying out a statistical analysis of the mean absolute errors with respect to the experiment. The calculated PNOF6 electric moments agree satisfactorily with the corresponding experimental data, and are in good agreement with the values obtained by accurate ab initio methods, namely, the coupled-cluster single and doubles (CCSD) and multi-reference single and double excitation configuration interaction (MRSD-CI) methods.

  4. Effects of functional electrical therapy on upper extremity functional motor recovery in patients after stroke: Our experience and future directions

    Directory of Open Access Journals (Sweden)

    Plavšić Aleksandra

    2011-01-01

    Full Text Available Introduction. New neurorehabilitation together with conventional techniques provide methods and technologies for maximizing what is preserved from the sensory motor system after cerebrovascular insult. The rehabilitation technique named functional electrical therapy was investigated in more than 60 patients in acute, subacute and chronic phase after cerebrovascular insult. The functional sensory information generated by functional electrical therapy was hypothesized to result in the intensive functional brain training of the activities performed. Functional Electrical Therapy. Functional electrical therapy is a combination of functional exercise and electrical therapy. The functional electrical therapy protocol comprises voluntary movement of the paretic arm in synchrony with the electrically assisted hand functions in order to perform typical daily activities. The daily treatment of 30 minutes lasts three weeks. The outcome measures include several tests for the evaluation of arm/hand functionality: upper extremity function test, drawing test, modified Aschworth scale, motor activity log and passive range of movement. Results of Functional Electrical Therapy Studies. Results from our several clinical studies showed that functional electrical therapy, if applied in acute and subacute stroke patients, leads to faster and greater improvement of functioning of the hemiplegic arm/hand compared to the control group. The outcomes were significantly superior at all times after the treatment for the higher functioning group. Discussion. Additional well-planned clinical studies are needed to determine the adequate dose of treatment (timing, duration, intensity with functional electrical therapy regarding the patient’s status. A combination with other techniques should be further investigated.

  5. A distributed transducer system for functional electrical stimulation

    DEFF Research Database (Denmark)

    Gudnason, Gunnar; Nielsen, Jannik Hammel; Bruun, Erik;

    2001-01-01

    Implanted transducers for functional electrical stimulation (FES) powered by inductive links are subject to conflicting requirements arising from low link efficiency, a low power budget and the need for protection of the weak signals against strong RF electromagnetic fields. We propose a solution...... likely to be affected by the inductive link. Neural stimulators are affected to a lesser degree, but still benefit from the partitioning. As a test case, we have designed a transceiver and a sensor chip which implement this partitioning policy. The transceiver is designed to operate in the 6.78 MHz ISM...

  6. Safety measures implemented for modular functioning electrical stimulators.

    Science.gov (United States)

    Chen, Chiun-Fan; Lai, Jin-Shin; Chen, Shih-Wei; Lin, Yin-Tsong; Kuo, Te-Son

    2009-01-01

    The modular architecture allows for greater flexibility in the building of neural prostheses with a variety of channels but may result in unpredictable accidents under circumstances such as sensor displacements, improper coordination of the connected modules and malfunction of any individual module. A novel fail-safe interface is offered as a solution that puts in place the necessary safety measures when building a module based functional electrical stimulator. By using a single reference line in the interconnecting bus of the modules, various commands would immediately be directed to each module so that proper actions may be taken.

  7. Modeling hourly Electricity Spot Market Prices as non stationary functional times series

    OpenAIRE

    Liebl, Dominik

    2010-01-01

    The instantaneous nature of electricity distinguishes its spot prices from spot prices for equities and other commodities. Up to now electricity cannot be stored economically and therefore demand for electricity has an untempered effect on electricity prices. In particular, hourly electricity spot prices show a vast range of dynamics which can change rapidly. In this paper we introduce a robust version of functional principal component analysis for sparse data. The functional perspective inte...

  8. A clinical exercise system for paraplegics using functional electrical stimulation.

    Science.gov (United States)

    Bremner, L A; Sloan, K E; Day, R E; Scull, E R; Ackland, T

    1992-09-01

    A low cost clinical exercise system was developed for the spinal cord injured, based on a bicycle ergometer and electrical stimulation. A pilot project was conducted, using the system, to examine the effects of stimulation induced cycling in long term paraplegics. The project comprised 2 phases of exercise, a strengthening phase involving a 12 week programme of electrical stimulation to the quadriceps and hamstrings and a 12 week cycling phase. Physiological, morphological and biochemical parameters were measured for each subject, at the beginning of the programme and following each phase. Results showed that a programme of stimulation induced lower limb exercise increased the exercise tolerance of all patients, as determined by a progressive increase in exercise time, cycling rate and exercise load. The enhanced exercise tolerance was a result of increases in local muscle strength and endurance. Increases in thigh muscle area and joint range of motion were recorded and all incomplete subjects reported an improvement in functional capabilities and general wellbeing. PMID:1408342

  9. Lung Ventilation Functional Monitoring Based on Electrical Impedance Tomography

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiaoyan; WANG Huaxiang; ZHAO Bo; SHI Xiaolei

    2009-01-01

    Medically,electrical impedance tomography(EIT)is a relatively inexpensive,safe,non-invasive and portable technique compared with computerized tomography(CT)and magnetic resonance imaging(MRI).In this paper,EIT_TJU_Ⅱ system is developed including both the data collection system and image reconstruction algorithm.The testing approach of the system performance,including spatial resolution and sensitivity,is described through brine tank experiments.The images of the thorax physical model verify that the system can reconstruct the interior resistivity distribution.Finally,the lung ventilation functional monitoring in vivo is realized by EIT,and the visualized images indicate that the configuration and performance of EIT_TJU_Ⅱ system are feasible and EIT is a promising technique in clinical monitoring application.

  10. Experimental Economics for Teaching the Functioning of Electricity Markets

    Science.gov (United States)

    Guevara-Cedeno, J. Y.; Palma-Behnke, R.; Uribe, R.

    2012-01-01

    In the field of electricity markets, the development of training tools for engineers has been extremely useful. A novel experimental economics approach based on a computational Web platform of an electricity market is proposed here for the practical teaching of electrical engineering students. The approach is designed to diminish the gap that…

  11. Interaction of poststroke voluntary effort and functional neuromuscular electrical stimulation

    Directory of Open Access Journals (Sweden)

    Nathaniel Makowski

    2013-02-01

    Full Text Available Functional electrical stimulation (FES may be able to augment functional arm and hand movement after stroke. Poststroke neuroprostheses that incorporate voluntary effort and FES to produce the desired movement must consider how forces generated by voluntary effort and FES combine, even in the same muscle, in order to provide an appropriate level of stimulation to elicit the desired assistive force. The goal of this study was to determine whether the force produced by voluntary effort and FES add together independently of effort or whether the increment in force depends on the level of voluntary effort. Isometric force matching tasks were performed under different combinations of voluntary effort and FES. Participants reached a steady level of force, and while attempting to maintain a constant effort level, FES was applied to augment the force. Results indicate that the increment in force produced by FES decreases as the level of initial voluntary effort increases. Potential mechanisms causing the change in force output are proposed, but the relative contribution of each mechanism is unknown.

  12. Brain-controlled telepresence robot by motor-disabled people.

    Science.gov (United States)

    Tonin, Luca; Carlson, Tom; Leeb, Robert; del R Millán, José

    2011-01-01

    In this paper we present the first results of users with disabilities in mentally controlling a telepresence robot, a rather complex task as the robot is continuously moving and the user must control it for a long period of time (over 6 minutes) to go along the whole path. These two users drove the telepresence robot from their clinic more than 100 km away. Remarkably, although the patients had never visited the location where the telepresence robot was operating, they achieve similar performances to a group of four healthy users who were familiar with the environment. In particular, the experimental results reported in this paper demonstrate the benefits of shared control for brain-controlled telepresence robots. It allows all subjects (including novel BMI subjects as our users with disabilities) to complete a complex task in similar time and with similar number of commands to those required by manual control. PMID:22255272

  13. Brain-controlled telepresence robot by motor-disabled people.

    Science.gov (United States)

    Tonin, Luca; Carlson, Tom; Leeb, Robert; del R Millán, José

    2011-01-01

    In this paper we present the first results of users with disabilities in mentally controlling a telepresence robot, a rather complex task as the robot is continuously moving and the user must control it for a long period of time (over 6 minutes) to go along the whole path. These two users drove the telepresence robot from their clinic more than 100 km away. Remarkably, although the patients had never visited the location where the telepresence robot was operating, they achieve similar performances to a group of four healthy users who were familiar with the environment. In particular, the experimental results reported in this paper demonstrate the benefits of shared control for brain-controlled telepresence robots. It allows all subjects (including novel BMI subjects as our users with disabilities) to complete a complex task in similar time and with similar number of commands to those required by manual control.

  14. Electrical conductivity of shocked water from Density Functional Theory

    Science.gov (United States)

    Mattsson, Thomas R.

    2005-07-01

    We present Density Functional Theory (DFT) calculations of water in a region of phase space of interest in shock experiments. The onset of electrical conductivity in shocked water is determined by ionic conductivity, with the electron contribution dominating at higher pressures. The ionic contribution to the conduction is calculated from proton diffusion (Green-Kubo formula) and the electronic contribution is calculated using the Kubo-Greenwood formula [1]. The calculations are performed with VASP, a plane-wave pseudopotential code. At 2000K and a density of 2.3 g/cc, we find a significant dissociation of water into H, OH, and H3O, not only intermittent formation of OH - H3O pairs as suggested earlier for 2000 K and 1.95 g/cc [2]. The calculated conductivity is compared to experimental data [3]. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Safety Administration under contract DE-AC04-94AL85000. This project was supported by the Sandia LDRD office. [1] M. P. Desjarlais, J. D. Kress, and L. A. Collins; Phys. Rev. B 66, 025401 (2002). [2] E. Schwegler, et al. Phys. Rev. Lett. 87, 265501 (2001). [3] P.M. Celliers, et. al. Physics of Plasmas 11, L41 (2004).

  15. Managing the GPS/GIS function in an electric utility

    International Nuclear Information System (INIS)

    A new period of higher significance has arrived for the GPS/GIS function at electric utilities such that to a degree never seen before, utility managers are looking to their GIS programs, filled with increasingly accurate data collected by GPS technology, before making many decisions. With this capability comes an expectation for GPS/GIS professionals to provide higher levels of planning and management of their data collection process. At Duke Power in Charlotte, North Carolina, managers rely on GPS mapping to fill their data collection equipment needs. When the city of Charlotte requested a more detailed billing system, Duke Power co-sponsored the street lighting inventory project, a comprehensive program implemented to fully account for street lighting facilities within the billing area. One of the key projects to be kept in mind was the creation of a common data base viewable by GIS from which a bill could be created and as well reveal data. A billing calculation routine can be run against the data base to generate a bill or use MapInfo to see a graphical picture. Prior to the creation of this data base capability, the difference between the data base as a display tool and billing system was a potential source of discrepancy, which is eliminated now. Creating the data base allows more than just creating a bill for the city, it allows Duke Power to work better with the city by improving its billing accountability and provides better service as well

  16. Electrical activity patterns and the functional maturation of the neocortex.

    Science.gov (United States)

    Kilb, Werner; Kirischuk, Sergei; Luhmann, Heiko J

    2011-11-01

    At the earliest developmental stages, sensory neocortical areas in various species reveal distinct patterns of spontaneous neuronal network activity. These activity patterns either propagate over large neocortical areas or synchronize local neuronal ensembles. In vitro and in vivo experiments indicate that these spontaneous activity patterns are generated from neuronal networks in the cerebral cortex, in subcortical structures or in the sensory periphery (retina, cochlea, whiskers). At early stages spontaneous periphery-driven and also sensory evoked activity is relayed to the developing cerebral cortex via the thalamus and the neocortical subplate, which amplifies the afferent sensory input. These early local and large-scale neuronal activity patterns influence a variety of developmental processes during corticogenesis, such as neurogenesis, apoptosis, neuronal migration, differentiation and network formation. The experimental data also indicate that disturbances in early neuronal patterns may have an impact on the development of cortical layers, columns and networks. In this article we review our current knowledge on the origin of early electrical activity patterns in neocortical sensory areas and their functional implications on shaping developing cortical networks.

  17. Electrical properties of two-dimensional thin films of the ferroelectric material Polyvinylidene Fluoride as a function of electric field

    Energy Technology Data Exchange (ETDEWEB)

    Belouadah, R., E-mail: r_belouadah74@yahoo.f [Departement de physique, Universite de M' sila, PB 116 Ichebilia, M' sila (Algeria); Laboratoire des Systemes Integres a base de Capteurs, Ecole Normale Superieure B.P 92 Kouba, Alger (Algeria); Kendil, D.; Bousbiat, E. [Laboratoire des Systemes Integres a base de Capteurs, Ecole Normale Superieure B.P 92 Kouba, Alger (Algeria); Guyomar, D.; Guiffard, B. [Laboratoire de Genie Electrique et Ferroelectricite, INSA-Lyon, Bat. Gustave Ferrie, 8 rue de la Physique, Villeurbanne (France)

    2009-06-01

    The study of the electrical properties of two-dimensional ferroelectric materials is very interesting because of the many possible applications relating to effects on their polarization properties. In this work we study the effect of a sinusoidal electric field on the dielectric and electrical properties of uni-axially and biaxially stretched polyvinylidene fluoride (PVDF) films. We have determined the polarization current, remanent polarization, maximal polarization, the hysteresis loop and coercive field as a function of applied electric field amplitude. The most interesting effects are the electric field (E) dependences of the resistivity. It is shown that for the biaxially stretched PVDF sample, the resistivity is almost constant, whereas for the uni-axially stretched specimen, a large decrease of resistivity is observed.

  18. Electrical properties of two-dimensional thin films of the ferroelectric material Polyvinylidene Fluoride as a function of electric field

    International Nuclear Information System (INIS)

    The study of the electrical properties of two-dimensional ferroelectric materials is very interesting because of the many possible applications relating to effects on their polarization properties. In this work we study the effect of a sinusoidal electric field on the dielectric and electrical properties of uni-axially and biaxially stretched polyvinylidene fluoride (PVDF) films. We have determined the polarization current, remanent polarization, maximal polarization, the hysteresis loop and coercive field as a function of applied electric field amplitude. The most interesting effects are the electric field (E) dependences of the resistivity. It is shown that for the biaxially stretched PVDF sample, the resistivity is almost constant, whereas for the uni-axially stretched specimen, a large decrease of resistivity is observed.

  19. Searching for Electrical Properties, Phenomena and Mechanisms in the Construction and Function of Chromosomes

    Directory of Open Access Journals (Sweden)

    Ivan Kanev

    2013-03-01

    Full Text Available Our studies reveal previously unidentified electrical properties of chromosomes: (1 chromosomes are amazingly similar in construction and function to electrical transformers; (2 chromosomes possess in their construction and function, components similar to those of electric generators, conductors, condensers, switches, and other components of electrical circuits; (3 chromosomes demonstrate in nano-scale level electromagnetic interactions, resonance, fusion and other phenomena similar to those described by equations in classical physics. These electrical properties and phenomena provide a possible explanation for unclear and poorly understood mechanisms in clinical genetics including: (a electrically based mechanisms responsible for breaks, translocations, fusions, and other chromosomal abnormalities associated with cancer, intellectual disability, infertility, pregnancy loss, Down syndrome, and other genetic disorders; (b electrically based mechanisms involved in crossing over, non-disjunction and other events during meiosis and mitosis; (c mechanisms demonstrating heterochromatin to be electrically active and genetically important.

  20. SPLITTING OF THE SPECTRAL DOMAIN ELECTRICAL DYADIC GREEN'S FUNCTION IN CHIRAL MEDIA

    Institute of Scientific and Technical Information of China (English)

    QIN Zhi-an; QIN Rui; CHEN Yan; SHENG De-yuan

    2005-01-01

    A new method of formulating dyadic Green's functions in lossless , reciprocal and unbounded chiral medium was presented. Based on Helmholtz theorem and the nondivergence and irrotational splitting of dyadic Dirac delta-function was this method, the electrical vector dyadic Green's function equation was first decomposed into the nondivergence electrical vector dyadic Green's function equation and irrotational electrical vector dyadic Green's function equation, and then Fourier's transformation was used to derive the expressions of the non-divergence and irrotational component of the spectral domain electrical dyadic Green's function in chiral media. It can avoid having to use the wavefield decomposition method and dyadic Green's function eigenfunction expansion technique that this method is used to derive the dyadic Green's functions in chiral media.

  1. Change of Work Function of Pd, Ag, K on Al(001) as a Function of External Electric Field

    Institute of Scientific and Technical Information of China (English)

    侯柱峰; 黄美纯; 朱梓忠; 黄荣彬; 郑兰荪

    2001-01-01

    We present a local density functional calculation of the effect of an external electric field on the work function change of Pd and Ag adsorption on an Al(001) surface. The adsorption of K has also been considered for comparison. We found that the work functions for all the systems increased linearly when the strength of the external electric field was increased. Since the polarized electrons at the interstitial regions between the adsorbate and substrate for Pd/Al(001) and Ag/Al(001) react to the external electric field differently, the subtle differences between Pd/Al(001) and Ag/Al(001) bondings has been characterized through the comparison of the slopes of the work function change versus electric field.

  2. 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.

  3. Muscular urinary sphincter : electrically stimulated myoplasty for functional sphincter reconstruction

    NARCIS (Netherlands)

    Palacio, M M; Van Aalst, V C; Perez Abadia, G A; Stremel, R W; Werker, P M; Ren, X; Petty, G D; Heilman, S J; Van Savage, J G; Garcia Fernandez, A; Kon, M; Tobin, G R; Barker, J H

    1998-01-01

    PURPOSE: To reconstruct an electrically stimulated muscular urinary sphincter (MUS) using a tailored gracilis muscle free flap with intact nerve. MATERIALS AND METHODS: Unilateral surgically tailored gracilis muscle free flaps were transferred into the pelvis in eight dogs, leaving the obturator ner

  4. FUNCTIONAL ELECTRICAL STIMULATION FOR CONTROL OF EPILEPTIC SEIZURES

    DEFF Research Database (Denmark)

    Jiao, Jianhang

    Nearly 50 million people worldwide have epilepsy and one-third of them do not respond well to any antiepileptic drugs. Given the large population of patients experiencing drug resistant epilepsy, increased attention has been paid over the last two decades to the development of electrical stimulat...

  5. Determinants of electricity consumption function in Pakistan: Old wine in a new bottle

    International Nuclear Information System (INIS)

    The objective of the study is to re-investigate the multivariate electricity consumption function for Pakistan, particularly, economic growth, foreign direct investment and population growth over a 36-year time period, i.e., between 1975 and 2010. The study employed the bounds-testing procedure for cointegration which examines the short-run and long-run estimates. Dynamic short-run causality test is applied to determine the causality direction between electricity consumption and its determinants, by using Wald-F statistics. The results reveal that determinants of electricity consumption function are cointegrated and influx of foreign direct investment, income and population growth is positively related to electricity consumption in Pakistan. However, the intensity of these determinants is different on electricity consumption. If there is 1% increase in income, foreign direct investment and population growth; electricity consumption increases by 0.973%; 0.056% and 1.605%, respectively. This infers that income, foreign direct investment and population growth induce an increase in electricity consumption in Pakistan. Dynamic short-run causality test indicates that there has been unidirectional causality which is running from population growth to electricity consumption in Pakistan. - Highlights: ► To re-investigate the multivariate electricity consumption function for Pakistan. ► FDI, income and population growth are positively related to electricity consumption. The intensity of determinants is different on electricity consumption. ► Population growth exerts the major contributor to increase electricity consumption. ► Unidirectional causality running from population growth to electricity.

  6. Study of Liquid Mixtures Electrical Properties as a Function of Electrical Conductivity using Capacitive Sensor

    Directory of Open Access Journals (Sweden)

    P. Azimi Anaraki

    2014-01-01

    Full Text Available In this study design and operation of a capacitive cell sensor for liquid mixture monitoring is reported. Operation of the capacitance measurement module for such probe is based on the charge and discharge method. The capacitive effect of small drop of different liquids in tap water was studied using this capacitive sensor. A small percentage of contaminating agents such as oil in tap water is determined with a good sensitivity. Comparison of the measured resistances for different liquid mixtures shows a decrease by increasing Total Dissolved Solids (TDS. In another study the electrical capacitance of different solutions, mixture of ethanol and water, mixture of methanol and water, mixture of petroleum and water and other liquid mixtures were studied. It must be pointed out that the measuring capacitance of the sensor is different from that of the liquid capacitance, but the samples electrical characteristics can be compared relatively with each other. The effects of the electrical conductivity on the permittivity and conductance of different liquid mixtures are also investigated. The experimental results are promising concerning water liquids and verify the successful operation of such device as a liquid sensor and are a useful method for checking the electrical quality of the water mixture that is required for different applications.

  7. Local electric dipole moments for periodic systems via density functional theory embedding

    International Nuclear Information System (INIS)

    We describe a novel approach for the calculation of local electric dipole moments for periodic systems. Since the position operator is ill-defined in periodic systems, maximally localized Wannier functions based on the Berry-phase approach are usually employed for the evaluation of local contributions to the total electric dipole moment of the system. We propose an alternative approach: within a subsystem-density functional theory based embedding scheme, subset electric dipole moments are derived without any additional localization procedure, both for hybrid and non-hybrid exchange–correlation functionals. This opens the way to a computationally efficient evaluation of local electric dipole moments in (molecular) periodic systems as well as their rigorous splitting into atomic electric dipole moments. As examples, Infrared spectra of liquid ethylene carbonate and dimethyl carbonate are presented, which are commonly employed as solvents in Lithium ion batteries

  8. Local electric dipole moments for periodic systems via density functional theory embedding

    Energy Technology Data Exchange (ETDEWEB)

    Luber, Sandra, E-mail: sandra.luber@chem.uzh.ch [Institut für Chemie, Universität Zürich, Winterthurerstrasse 190, 8057 Zürich (Switzerland)

    2014-12-21

    We describe a novel approach for the calculation of local electric dipole moments for periodic systems. Since the position operator is ill-defined in periodic systems, maximally localized Wannier functions based on the Berry-phase approach are usually employed for the evaluation of local contributions to the total electric dipole moment of the system. We propose an alternative approach: within a subsystem-density functional theory based embedding scheme, subset electric dipole moments are derived without any additional localization procedure, both for hybrid and non-hybrid exchange–correlation functionals. This opens the way to a computationally efficient evaluation of local electric dipole moments in (molecular) periodic systems as well as their rigorous splitting into atomic electric dipole moments. As examples, Infrared spectra of liquid ethylene carbonate and dimethyl carbonate are presented, which are commonly employed as solvents in Lithium ion batteries.

  9. A novel functional electrical stimulation-control system for restoring motor function of post-stroke hemiplegic patients

    Institute of Scientific and Technical Information of China (English)

    Zonghao Huang; Zhigong Wang; Xiaoying Lv; Yuxuan Zhou; Haipeng Wang; Sihao Zong

    2014-01-01

    Hemiparesis is one of the most common consequences of stroke. Advanced rehabilitation tech-niques are essential for restoring motor function in hemiplegic patients. Functional electrical stimulation applied to the affected limb based on myoelectric signal from the unaffected limb is a promising therapy for hemiplegia. In this study, we developed a prototype system for evaluating this novel functional electrical stimulation-control strategy. Based on surface electromyography and a vector machine model, a self-administered, multi-movement, force-modulation functional electrical stimulation-prototype system for hemiplegia was implemented. This paper discusses the hardware design, the algorithm of the system, and key points of the self-oscillation-prone system. The experimental results demonstrate the feasibility of the prototype system for further clinical trials, which is being conducted to evaluate the efifcacy of the proposed rehabilitation technique.

  10. Effects of a multichannel dynamic functional electrical stimulation system on hemiplegic gait and muscle forces.

    Science.gov (United States)

    Qian, Jing-Guang; Rong, Ke; Qian, Zhenyun; Wen, Chen; Zhang, Songning

    2015-11-01

    [Purpose] The purpose of the study was to design and implement a multichannel dynamic functional electrical stimulation system and investigate acute effects of functional electrical stimulation of the tibialis anterior and rectus femoris on ankle and knee sagittal-plane kinematics and related muscle forces of hemiplegic gait. [Subjects and Methods] A multichannel dynamic electrical stimulation system was developed with 8-channel low frequency current generators. Eight male hemiplegic patients were trained for 4 weeks with electric stimulation of the tibia anterior and rectus femoris muscles during walking, which was coupled with active contraction. Kinematic data were collected, and muscle forces of the tibialis anterior and rectus femoris of the affected limbs were analyzed using a musculoskelatal modeling approach before and after training. A paired sample t-test was used to detect the differences between before and after training. [Results] The step length of the affected limb significantly increased after the stimulation was applied. The maximum dorsiflexion angle and maximum knee flexion angle of the affected limb were both increased significantly during stimulation. The maximum muscle forces of both the tibia anterior and rectus femoris increased significantly during stimulation compared with before functional electrical stimulation was applied. [Conclusion] This study established a functional electrical stimulation strategy based on hemiplegic gait analysis and musculoskeletal modeling. The multichannel functional electrical stimulation system successfully corrected foot drop and altered circumduction hemiplegic gait pattern.

  11. Density, dynamic viscosity, and electrical conductivity of two hydrophobic functionalized ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Targets of this research are functional hydrophobic ionic liquids. • Density, dynamic viscosity and electrical conductivity were determined. • Influences of functional group to properties were discussed. • Relationship of ρ, η and σ were described systematically. - Abstract: Two of hydrophobic functionalized ionic liquids (FILs) were synthesized according to the traditional method. The FILs are 1-(cyanomethyl)-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([MCNMIM][NTf2]) and 1-(2-hydroxyethyl)-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([EOHMIM][NTf2]). Density, dynamic viscosity, and electrical conductivity of the two FILs were determined in the range of T = (283.15 to 353.15) K. The other important physico-chemical properties, like molecular volume, standard molar entropy, and lattice energy, of the two FILs were estimated by empirical equations on the bases of the experimental density. The Vogel–Fulcher–Tamman (VFT) and Arrhenius equations were used for fitting of the temperature dependence of the dynamic viscosity and electrical conductivity. The activation of electrical conductivity and dynamic viscosity were calculated by the final version VFT equation. The molar conductivities were determined from density and electrical conductivity by the empirical equation. According to Walden rule, the Walden equation was used for description of the density, dynamic viscosity, and electrical conductivity. The introduction of the functional group (cyano and hydroxy) on imidazolium ring can provided hydrogen bond formation. The FILs exhibited the higher density, dynamic viscosity and lower electrical conductivity than traditional non-functional ILs

  12. Calculate Electric Field Gradient of TiO2 Within Density Functional Theory

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>TiO2 electric field gradient has been calculated utilizing WIEN2K program, which is ab initio based on density function theory (DFT). DFT uses the charge density as a variable instead of electronic wave

  13. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke

    OpenAIRE

    Marta Gandolla; Ward, Nick S; Franco Molteni; Eleonora Guanziroli; Giancarlo Ferrigno; Alessandra Pedrocchi

    2016-01-01

    Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chron...

  14. Efficient and accurate computation of electric field dyadic Green's function in layered media

    CERN Document Server

    Cho, Min Hyung

    2016-01-01

    Concise and explicit formulas for dyadic Green's functions, representing the electric and magnetic fields due to a dipole source placed in layered media, are derived in this paper. First, the electric and magnetic fields in the spectral domain for the half space are expressed using Fresnel reflection and transmission coefficients. Each component of electric field in the spectral domain constitutes the spectral Green's function in layered media. The Green's function in the spatial domain is then recovered involving Sommerfeld integrals for each component in the spectral domain. By using Bessel identities, the number of Sommerfeld integrals are reduced, resulting in much simpler and more efficient formulas for numerical implementation compared with previous results. This approach is extended to the three-layer Green's function. In addition, the singular part of the Green's function is naturally separated out so that integral equation methods developed for free space Green's functions can be used with minimal mo...

  15. Functionalized perylenes: origin of the enhanced electrical performances

    NARCIS (Netherlands)

    Piliego, C.; Cordella, F.; Jarzab, D.; Lu, S.; Chen, Z.; Facchetti, A.; Loi, M.A.

    2009-01-01

    {In this letter we compare the transistor performances of two solution-processed perylene derivatives: N,N'-bis (n-octyl)- dicyanoperylene-3,4:9,10-bis(dicarboximide) (PDI8-CN2) and N,N'-1H,1H-perfluorobutyl dicyanoperylenediimide (PDIF-CN2). Perylenediimide nitrogen functionalization with perfluoro

  16. The electricity exchange. On the organisation and latent functions of electricity exchange trading as seen from the viewpoint of market sociology

    International Nuclear Information System (INIS)

    Electricity exchange trading in Germany has existed since the year 2000. Since this time, the Leipzig electricity exchange, a reference market for off-exchange electricity trading, has operated in an environment marked by both criticism and acceptance. Taking this field of controversy as a point of departure the present empirical study in market sociology undertakes to investigate the organisation and latent functions of electricity exchange trading. The ensuing analysis provides answers to questions as to how prices are formed on the electricity exchange and what officially incommunicable functions are served by price formation on exchanges.

  17. Nanowires and Electrical Stimulation Synergistically Improve Functions of hiPSC Cardiac Spheroids.

    Science.gov (United States)

    Richards, Dylan J; Tan, Yu; Coyle, Robert; Li, Yang; Xu, Ruoyu; Yeung, Nelson; Parker, Arran; Menick, Donald R; Tian, Bozhi; Mei, Ying

    2016-07-13

    The advancement of human induced pluripotent stem-cell-derived cardiomyocyte (hiPSC-CM) technology has shown promising potential to provide a patient-specific, regenerative cell therapy strategy to treat cardiovascular disease. Despite the progress, the unspecific, underdeveloped phenotype of hiPSC-CMs has shown arrhythmogenic risk and limited functional improvements after transplantation. To address this, tissue engineering strategies have utilized both exogenous and endogenous stimuli to accelerate the development of hiPSC-CMs. Exogenous electrical stimulation provides a biomimetic pacemaker-like stimuli that has been shown to advance the electrical properties of tissue engineered cardiac constructs. Recently, we demonstrated that the incorporation of electrically conductive silicon nanowires to hiPSC cardiac spheroids led to advanced structural and functional development of hiPSC-CMs by improving the endogenous electrical microenvironment. Here, we reasoned that the enhanced endogenous electrical microenvironment of nanowired hiPSC cardiac spheroids would synergize with exogenous electrical stimulation to further advance the functional development of nanowired hiPSC cardiac spheroids. For the first time, we report that the combination of nanowires and electrical stimulation enhanced cell-cell junction formation, improved development of contractile machinery, and led to a significant decrease in the spontaneous beat rate of hiPSC cardiac spheroids. The advancements made here address critical challenges for the use of hiPSC-CMs in cardiac developmental and translational research and provide an advanced cell delivery vehicle for the next generation of cardiac repair.

  18. Electrical properties of functionalized nanowire field effect transistors

    OpenAIRE

    Weitz, Ralf Thomas

    2008-01-01

    The utilization of functional organic materials holds great promise for applications in electronic devices. Semiconducting organic molecules are frequently used as channel material in field effect transistors, due to the ease by which they can be assembled as such components, and the ease with which their properties can be specifically tailored. An extension of the use of organic materials in field effect transistors with the potential to substantially improve the performance of such devices ...

  19. Functional electrical stimulation-assisted walking for persons with incomplete spinal injuries

    DEFF Research Database (Denmark)

    Ladouceur, M.; Barbeau, H.

    2000-01-01

    This study investigated the changes in maximal overground walking speed (MOWS) that occurred during; walking training with a functional electrical stimulation (FES) orthosis by chronic spinal cord injured persons with incomplete motor function loss. The average walking: speed over a distance of 10...

  20. Effects of Functional Electrical Stimulation on Gait Function and Quality of Life for People with Multiple Sclerosis Taking Dalfampridine

    OpenAIRE

    Mayer, Lori; Warring, Tina; Agrella, Stephanie; Rogers, Helen L.; Fox, Edward J.

    2015-01-01

    Background: Multiple sclerosis (MS) can adversely affect gait, causing gait slowing, loss of balance, decreased functional mobility, and gait deficits, such as footdrop. Current treatments for gait dysfunction due to MS are pharmacologic, using dalfampridine, or orthotic, using an ankle-foot orthosis. Functional electrical stimulation (FES) to the fibular nerve stimulates active dorsiflexion and provides an alternative treatment for gait dysfunction caused by footdrop. The objective of this s...

  1. Modeling and control of a power converter for electric vehicle integrating battery charging function

    OpenAIRE

    Lacroix, Samantha

    2013-01-01

    Environmental constraints and reduction of fossil fuels resources have led industrials and laboratories to search for alternative solutions in the transportation domain. For the last few years, several vehicles or planes functions have been gradually electrified, up to their complete electrification. This thesis presents an AC/DC converter integrated in an Electric Vehicle (EV) for the charger application. The conversion is realized by using the electric traction powertrain, in order to reduc...

  2. The supply function equilibrium and its policy implications for wholesale electricity auctions

    Energy Technology Data Exchange (ETDEWEB)

    Holmberg, Paer [Research Institute of Industrial Economics (IFN), Box 55665, Grevgatan 34, 10215 Stockholm (Sweden); Newbery, David [Faculty of Economics, University of Cambridge, Cambridge (United Kingdom)

    2010-12-15

    The supply function equilibrium provides a game-theoretic model of strategic bidding in oligopolistic wholesale electricity auctions. This paper presents an intuitive account of current understanding and shows how welfare losses depend on the number of firms in the market and their asymmetry. Previous results and general recommendations for divisible-good/multi-unit auctions provides guidance on the design of the auction format, setting the reservation price, the rationing rule, and restrictions on the offer curves in wholesale electricity auctions. (author)

  3. Influence of functionalization on mechanical and electrical properties of carbon nanotube-based silver composites

    Science.gov (United States)

    Pal, Hemant; Sharma, Vimal; Sharma, Manjula

    2014-05-01

    In this study, we have extended the molecular-level mixing method to fabricate multiwall carbon nanotube (CNT)-reinforced silver nanocomposites. The multiwall nanotubes used in the synthesis process were dispersed by two ways viz. covalent and non-covalent functionalization techniques. To elucidate the comparative effects of functionalization, structural, mechanical and electrical properties of nanocomposites were evaluated before and after sintering. The structural characterization revealed that the nanotubes were embedded, anchored and homogenously dispersed within the silver matrix. Hardness and Young's modulus of nanotube-reinforced nanocomposite were increased by a factor of 1-1.6 times than that of pure silver, even before and after the sintering. Covalently functionalized nanotube-based composites have shown more enhanced mechanical properties. The CNT reinforcement also improved the electrical conductivity of low-conducting nanosilver matrix before sintering. Non-covalently functionalized nanotube-based nanosilver composites showed more increased electrical conductivity before sintering. But a negative reinforcement effect was observed in high-conducting bulk silver matrix after the sintering. Thus, covalent functionalization might be appropriate for mechanical improvement in low-strength materials. However, non-covalent functionalization is suitable for electrical enhancement in low-conducting nanomaterials.

  4. Structural and electrical properties of functionalized multiwalled carbon nanotube/epoxy composite

    Science.gov (United States)

    Gantayat, S.; Rout, D.; Swain, S. K.

    2016-05-01

    The effect of the functionalization of multiwalled carbon nanotube on the structure and electrical properties of composites was investigated. Samples based on epoxy resin with different weight percentage of MWCNTs were prepared and characterized. The interaction between MWCNT & epoxy resin was noticed by Fourier transform infrared spectroscopy (FTIR). The structure of functionalized multiwalled carbon nanotube (f-MWCNT) reinforced epoxy composite was studied by field emission scanning electron microscope (FESEM). The dispersion of f-MWCNT in epoxy resin was evidenced by high resolution transmission electron microscope (HRTEM). Electrical properties of epoxy/f-MWCNT nanocomposites were measured & the result indicated that the conductivity increased with increasing concentration of f-MWCNTs.

  5. Electrical transport of SiNWs array after covalent attachment of new organic functionalities

    Directory of Open Access Journals (Sweden)

    Marianna Ambrico

    2012-05-01

    Full Text Available Modification of the electrical transport of a random network of silicon nanowires assembled on n‐ silicon support, after silicon nanowires functionalization by chlorination/alkylation procedure , is here described and discussed. We show that the organic functionalities induce charge transfer at single SiNW and produce doping‐like effect that is kept in the random network too. The\tSiNWs\tnetwork\talso\tpresents\ta\tsurface recombination velocity lower than that of bulk silicon. Interestingly, the functionalized silicon nanowires/n‐Si junctions display photo‐yield and open circuit voltages higher than those including oxidized silicon nanowire networks. Electrical properties stability in time of junctions embedding propenyl terminated silicon nanowires network and transport modification after secondary functionalization is also shown. These results suggest a possible route for the integration of functionalized\tSi\tnanowires,\talthough\trandomly distributed, in stable large area photovoltaic or molecule sensitive based devices.

  6. Evolutionary History of a Brain Controlling Brain Size

    OpenAIRE

    Natalay Kouprina; Adam Pavlicek; Mochida, Ganeshwaran H.; Gregory Solomon; William Gersch; Young-Ho Yoon; Randall Collura; Maryellen Ruvolo; J Carl Barrett; C Geoffrey Woods; Walsh, Christopher A.; Jerzy Jurka; Vladimir Larionov

    2004-01-01

    Primary microcephaly (MCPH) is a neurodevelopmental disorder characterized by global reduction in cerebral cortical volume. The microcephalic brain has a volume comparable to that of early hominids, raising the possibility that some MCPH genes may have been evolutionary targets in the expansion of the cerebral cortex in mammals and especially primates. Mutations in ASPM, which encodes the human homologue of a fly protein essential for spindle function, are the most common known cause of MCPH....

  7. Electric Field Encephalography as a tool for functional brain research: a modeling study.

    Directory of Open Access Journals (Sweden)

    Yury Petrov

    Full Text Available We introduce the notion of Electric Field Encephalography (EFEG based on measuring electric fields of the brain and demonstrate, using computer modeling, that given the appropriate electric field sensors this technique may have significant advantages over the current EEG technique. Unlike EEG, EFEG can be used to measure brain activity in a contactless and reference-free manner at significant distances from the head surface. Principal component analysis using simulated cortical sources demonstrated that electric field sensors positioned 3 cm away from the scalp and characterized by the same signal-to-noise ratio as EEG sensors provided the same number of uncorrelated signals as scalp EEG. When positioned on the scalp, EFEG sensors provided 2-3 times more uncorrelated signals. This significant increase in the number of uncorrelated signals can be used for more accurate assessment of brain states for non-invasive brain-computer interfaces and neurofeedback applications. It also may lead to major improvements in source localization precision. Source localization simulations for the spherical and Boundary Element Method (BEM head models demonstrated that the localization errors are reduced two-fold when using electric fields instead of electric potentials. We have identified several techniques that could be adapted for the measurement of the electric field vector required for EFEG and anticipate that this study will stimulate new experimental approaches to utilize this new tool for functional brain research.

  8. Application of electrical stimulation for functional tissue engineering in vitro and in vivo

    Science.gov (United States)

    Radisic, Milica (Inventor); Park, Hyoungshin (Inventor); Langer, Robert (Inventor); Freed, Lisa (Inventor); Vunjak-Novakovic, Gordana (Inventor)

    2013-01-01

    The present invention provides new methods for the in vitro preparation of bioartificial tissue equivalents and their enhanced integration after implantation in vivo. These methods include submitting a tissue construct to a biomimetic electrical stimulation during cultivation in vitro to improve its structural and functional properties, and/or in vivo, after implantation of the construct, to enhance its integration with host tissue and increase cell survival and functionality. The inventive methods are particularly useful for the production of bioartificial equivalents and/or the repair and replacement of native tissues that contain electrically excitable cells and are subject to electrical stimulation in vivo, such as, for example, cardiac muscle tissue, striated skeletal muscle tissue, smooth muscle tissue, bone, vasculature, and nerve tissue.

  9. An electrically tunable imaging system with separable focus and zoom functions using composite liquid crystal lenses.

    Science.gov (United States)

    Chen, Ming-Syuan; Chen, Po-Ju; Chen, Michael; Lin, Yi-Hsin

    2014-05-19

    We demonstrated an electrically tunable optical image system with separable focus function and zoom function based on three tunable focusing composite liquid crystal (LC) lenses. One LC lens in charge of the focus function helps to maintain the formed image at the same position and the other two LC lenses in charge of zoom function assist to continuously form an image at image sensor with tunable magnification of image size. The detail optical mechanism is investigated and the concept is demonstrated experimentally. The magnifications of the images can be switched continuously for the target in a range between 10 cm and 100 cm. The optical zoom ratio of this system maintains a constant~6.5:1 independent of the object distance. This study provides not only a guideline to design the image system with an electrically optical zoom, but also provide an experimental process to show how to operate the tunable focusing lenses in such an image system.

  10. Study of the Electrical Double Layer of a Spherical Micelle:Functional Theoretical Approach

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By using the iterative method in functional theory, an analytic expression of the Poisson-Boltzmann equation (PB eq.), which describes the distribution of the potential of electrical double layer of a spherical micelle, has been carried out under the general potential condition for the first time. The method also can give the radius, the surface potential, and the thickness of the layer.

  11. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke.

    Science.gov (United States)

    Gandolla, Marta; Ward, Nick S; Molteni, Franco; Guanziroli, Eleonora; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chronic stroke patients receiving functional electrical stimulation for foot-drop correction. Patients exhibited task-related activation in a complex network, sharing bilateral sensorimotor and supplementary motor activation with age-matched controls. We observed consistent separation of patients with and without carryover effect on the basis of brain responses. Patients who experienced the carryover effect had responses in supplementary motor area that correspond to healthy controls; the interaction between experimental factors in contralateral angular gyrus was seen only in those without carryover. We suggest that the functional electrical stimulation carryover mechanism of action is based on movement prediction and sense of agency/body ownership-the ability of a patient to plan the movement and to perceive the stimulation as a part of his/her own control loop is important for carryover effect to take place. PMID:27073701

  12. The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke

    Directory of Open Access Journals (Sweden)

    Marta Gandolla

    2016-01-01

    Full Text Available Neurorehabilitation effective delivery for stroke is likely to be improved by establishing a mechanistic understanding of how to enhance adaptive plasticity. Functional electrical stimulation is effective at reducing poststroke foot drop; in some patients, the effect persists after therapy has finished with an unknown mechanism. We used fMRI to examine neural correlates of functional electrical stimulation key elements, volitional intent to move and concurrent stimulation, in a group of chronic stroke patients receiving functional electrical stimulation for foot-drop correction. Patients exhibited task-related activation in a complex network, sharing bilateral sensorimotor and supplementary motor activation with age-matched controls. We observed consistent separation of patients with and without carryover effect on the basis of brain responses. Patients who experienced the carryover effect had responses in supplementary motor area that correspond to healthy controls; the interaction between experimental factors in contralateral angular gyrus was seen only in those without carryover. We suggest that the functional electrical stimulation carryover mechanism of action is based on movement prediction and sense of agency/body ownership—the ability of a patient to plan the movement and to perceive the stimulation as a part of his/her own control loop is important for carryover effect to take place.

  13. Robotics combined with electrical stimulation: hybrid support of arm and hand for functional training after stroke

    OpenAIRE

    Westerveld, A.J.

    2014-01-01

    Reach, grasp and release is part of many functional movements. Graying of society leads to more stroke victims and fewer health care professionals. Technology might be a solution to support certain rehabilitation therapies in future health care. Robotic systems have been developed for support of arm and hand movements and functional electrical stimulation (FES) has been applied to activate arm and hand muscles. Therapeutic effects of both techniques have been shown similar to conventional the...

  14. Electrical measurement of moisturizing effect on skin hydration and barrier function in psoriasis patients.

    Science.gov (United States)

    Rim, J H; Jo, S J; Park, J Y; Park, B D; Youn, J I

    2005-07-01

    Transepidermal water loss (TEWL) in psoriatic skin lesions seems to be related to the severity of the psoriasis, and the electrical capacitance and conductance of the skin are indicators of the hydration level of the stratum corneum. We compared the characteristics of these electrical measurements, in assessing the persistent effect of a moisturizing cream on skin hydration and barrier function in psoriasis patients. Seventeen Korean psoriasis patients were recruited. Their right leg was treated with the moisturizer twice daily for 6 weeks, while their left leg was used as the control site. For each patient, one psoriatic plaque on each leg was selected as the involved psoriatic lesion. Uninvolved psoriatic skin was regarded as the apparently healthy looking skin 4-5 cm away from the periphery of the psoriatic lesion. The TEWL, electrical capacitance and conductance were measured, in order to evaluate the barrier function and hydration level of the stratum corneum. The clinical and biophysical data for each patient were recorded at the start of the study and after 2, 4 and 6 weeks. The degree of skin dryness at the applied area improved progressively. The electrical capacitance at the treated psoriatic lesion increased significantly after 2 weeks, and this improvement was maintained during the entire study period. However, no noticeable change was observed in the electrical conductance. The TEWL showed an inverse pattern to that of the skin capacitance, decreasing during the study period. The skin capacitance and TEWL exhibited good correlation with the visual assessment of skin dryness, but the skin conductance did not. Our data suggest that electrical capacitance and TEWL may be useful in the evaluation of the effect of a moisturizer on the hydration status and barrier function of psoriatic skin. PMID:15953083

  15. Does therapeutic electrical stimulation improve function in children with disabilities? A comprehensive literature review.

    Science.gov (United States)

    Bosques, Glendaliz; Martin, Rebecca; McGee, Leah; Sadowsky, Cristina

    2016-05-31

    The use of therapeutic electrical stimulation for medical purposes is not new; it has been described in medical textbooks since the 18th century, but its use has been limited due to concerns for tolerance and lack of research showing efficacy. The purpose of this review is to discuss the potential clinical applicability, while clarifying the differences in electrical stimulation (ES) treatments and the theory behind potential benefits to remediate functional impairments in youth.The literature review was performed as follows: A total of 37 articles were reviewed and the evidence for use in pediatric diagnoses is reported.The synthesis of the literature suggests that improvements in various impairments may be possible with the integration of ES. Most studies were completed on children with cerebral palsy (CP). Electrical stimulation may improve muscle mass and strength, spasticity, passive range of motion (PROM), upper extremity function, walking speed, and positioning of the foot and ankle kinematics during walking. Sitting posture and static/dynamic sitting balance may be improved with ES to trunk musculature. Bone mineral density may be positively affected with the use of Functional Electrical Stimulation (FES) ergometry. ES may also be useful in the management of urinary tract dysfunction and chronic constipation. Among all reviewed studies, reports of direct adverse reactions to electrical stimulation were rare.In conclusion, NMES and FES appear to be safe and well tolerated in children with various disabilities. It is suggested that physiatrists and other healthcare providers better understand the indications and parameters in order to utilize these tools effectively in the pediatric population. MeSH terms: Electrical stimulation; child; review. PMID:27285801

  16. ANALYSIS OF FUNCTIONAL ELECTRICAL ANNEX DIAGRAMS OF WIND ENERGY CONVERSION SYTEMS

    Directory of Open Access Journals (Sweden)

    S. G. Polovnikov

    2014-01-01

    Full Text Available The paper considers basic concepts in the design of modern wind energy conversion systems (WECS. The analysis of control methods and systems which are capable to realize operational mode  with maximum  output  power  has been presented in the paper.  Functional diagrams of systems for different electric generators, mechanical gears and various combinations of electric power supply and control systems have been have been given in the paper. WECS structures that meet the operational requirements in Belarus have been determined in the paper. 

  17. Mathematical model for studying the variation of the electrical parameters in functioning of nonlinear loads

    Science.gov (United States)

    Rob, Raluca; Rat, Cezara

    2013-10-01

    This paper presents a study concerning the variation of the most important electrical parameters, measured during the functioning of an electrothermal installation with electromagnetic induction. Two measuring methods are described: the first method consists in using a power and energy quality analyzer and the second uses a data acquisition system that contains an adapting interface and a data acquisition board connected to a computer. In order to compute the electrical parameters, a LabVIEW application was designed. The data acquisition system is able to measure in real time the variation of the parameters and also to save the obtained information.

  18. Electric Field Magnitude and Radar Reflectivity as a Function of Distance from Cloud Edge

    Science.gov (United States)

    Ward, Jennifer G.; Merceret, Francis J.

    2004-01-01

    The results of analyses of data collected during a field investigation of thunderstorm anvil and debris clouds are reported. Statistics of the magnitude of the electric field are determined as a function of distance from cloud edge. Statistics of radar reflectivity near cloud edge are also determined. Both analyses use in-situ airborne field mill and cloud physics data coupled with ground-based radar measurements obtained in east-central Florida during the summer convective season. Electric fields outside of anvil and debris clouds averaged less than 3 kV/m. The average radar reflectivity at the cloud edge ranged between 0 and 5 dBZ.

  19. Effects of the electric field on the properties of ZnO-graphene composites: a density functional theory study.

    Science.gov (United States)

    Geng, Wei; Zhao, Xuefei; Zan, Wenyan; Liu, Huanxiang; Yao, Xiaojun

    2014-02-28

    In this work, the effects of the electric field on the properties of ZnO-graphene composites were theoretically studied using density functional theory calculations. Three types of ZnO-graphene composites including composites of pristine graphene, graphene with defects as well as graphene oxide and a ZnO bilayer were studied. We calculated and analyzed the binding energies, charge transfer, band structures and work functions of the above composites under the external electric fields. The DFT calculation results demonstrate that the binding energies are sensitive to the electric field, and increasing the external electric field gives rise to stronger binding energies. The extent of charge transfer is correlated with the magnitude of the external electric field, but the band gaps are hardly affected by the external electric field. The work functions vary depending on the different structures of the composites and surface sides, and they are also tunable by the external electric field. PMID:24285715

  20. Effects of the electric field on the properties of ZnO-graphene composites: a density functional theory study.

    Science.gov (United States)

    Geng, Wei; Zhao, Xuefei; Zan, Wenyan; Liu, Huanxiang; Yao, Xiaojun

    2014-02-28

    In this work, the effects of the electric field on the properties of ZnO-graphene composites were theoretically studied using density functional theory calculations. Three types of ZnO-graphene composites including composites of pristine graphene, graphene with defects as well as graphene oxide and a ZnO bilayer were studied. We calculated and analyzed the binding energies, charge transfer, band structures and work functions of the above composites under the external electric fields. The DFT calculation results demonstrate that the binding energies are sensitive to the electric field, and increasing the external electric field gives rise to stronger binding energies. The extent of charge transfer is correlated with the magnitude of the external electric field, but the band gaps are hardly affected by the external electric field. The work functions vary depending on the different structures of the composites and surface sides, and they are also tunable by the external electric field.

  1. [Real-time Gait Training System with Embedded Functional Electrical Stimulation].

    Science.gov (United States)

    Gu, Linyan; Ruan, Zhaomin; Jia, Guifeng; Xla, Jing; Qiu, Lijian; Wu, Changwang; Jin, Xiaoqing; Ning, Gangmin

    2015-07-01

    To solve the problem that mostly gait analysis is independent from the treatment, this work proposes a system that integrates the functions of gait training and assessment for foot drop treatment. The system uses a set of sensors to collect gait parameters and designes multi-mode functional electrical stimulators as actuator. Body area network technology is introduced to coordinate the data communication and execution of the sensors and stimulators, synchronize the gait analysis and foot drop treatment. Bluetooth 4.0 is applied to low the power consumption of the system. The system realizes the synchronization of treatment and gait analysis. It is able to acquire and analyze the dynamic parameters of ankle, knee and hip in real-time, and treat patients by guiding functional electrical stimulation delivery to the specific body locations of patients.

  2. Effective Minimization of Nonsmooth Functions in the Limit Analysis Problem for Dielectrics in Powerful Electric Fields

    Directory of Open Access Journals (Sweden)

    Igor Albertovich Brigadnov

    2012-08-01

    Full Text Available The problem of minimization of ill-conditioned functions is considered. This problem arises as a result of finite-element approximation of the limit analysis problem for dielectrics in powerful electric fields. The objective function is nonsmooth therefore a smooth regularization of finite-dimensional problem is used. As a result distinct ravine of objective function is acquired. Convergence of the gradient and the heave-ball methods in relation to its internal and optimization parameters are studied inside the numerical computing environment and fourth-generation programming language Matlab.

  3. INTRINSIC ELECTRICAL PROPERTIES OF MAMMALIAN NEURONS AND CNS FUNCTION: A HISTORICAL PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Rodolfo R Llinas

    2014-11-01

    Full Text Available This brief review summarizes work done in mammalian neuroscience concerning the intrinsic electrophysiological properties of four neuronal types; Cerebellar Purkinje cells, inferior olivary cells, thalamic cells, and some cortical interneurons. It is a personal perspective addressing an interesting time in neuroscience when the reflex view of brain function, as the paradigm to understand global neuroscience, began to be modified towards one in which sensory input modulates rather than dictates brain function. The perspective of the paper is not a comprehensive description of the intrinsic electrical properties of all nerve cells but rather addresses a set of cell types that provide indicative examples of mechanisms that modulate brain function.

  4. Reconfigurable anisotropy and functional transformations with VO$_{2}$-based metamaterial electric circuits

    CERN Document Server

    Savo, Salvatore; Castaldi, Giuseppe; Moccia, Massimo; Galdi, Vincenzo; Ramanathan, Shriram; Sato, Yuki

    2014-01-01

    We demonstrate an innovative multifunctional artificial material that combines exotic metamaterial properties and the environmentally responsive nature of phase change media. The tunable metamaterial is designed with the aid of two interwoven coordinate-transformation equations and implemented with a network of thin film resistors and vanadium dioxide ($VO_{2}$). The strong temperature dependence of $VO_{2}$ electrical conductivity results in a relevant modification of the resistor network behavior, and we provide experimental evidence for a reconfigurable metamaterial electric circuit (MMEC) that not only mimics a continuous medium but is also capable of responding to thermal stimulation through dynamic variation of its spatial anisotropy. Upon external temperature change the overall effective functionality of the material switches between a "truncated-cloak" and "concentrator" for electric currents. Possible applications may include adaptive matching resistor networks, multifunctional electronic devices, an...

  5. Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

    Science.gov (United States)

    Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

    2012-01-01

    Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/ sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain s ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable providing imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles.

  6. Spin structure of germanene quantum dot as a func-tion of normal electric field

    Science.gov (United States)

    Vadym, Apalkov; Chaganti, Venkata

    2015-03-01

    Germanene quantum dot consisting of 13 germanium atoms is studied numerically within the nearest neighbor tight-binding model. Both the energy spectra and the spin structure of the corresponding Eigen-functions are obtained. Due to strong spin-orbit interaction in germanene the spin polarization of the germanene quantum dot strongly depends on the energy of the corresponding Eigen-state and on the external electric field, Ez. There are two states with energies close to zero, for which the direction of the spin is along z-axis, where z-axis is perpendicular of the quantum dot layer. For the higher energy levels the spin deviates from the z-axis with maximum angle θmax = 3.90 for the levels with energy 1128 meV (for electron channel) and -1128 meV (for hole channel) and zero electric field, Ez = 0. The angle θmax increases almost linearly with Ez and takes the value of 4.20 at Ez = 100 meV/Å. The in-plane direction of spin is also sensitive to external electric field. With increasing electric field, the in-plane spin rotates in the anticlockwise and clockwise directions for the 1128 meV and -1128 meV levels, respectively. Due to such sensitivity of spin polarization to external electric field, applying a bias voltage can control the spin current through germanene quantum dot.

  7. Tremor suppression using functional electrical stimulation: a comparison between digital and analog controllers.

    Science.gov (United States)

    Gillard, D M; Cameron, T; Prochazka, A; Gauthier, M J

    1999-09-01

    In this study, we compared digital and analog versions of a functional electrical stimulator designed to suppress tremor. The device was based on a closed-loop control system designed to attenuate movements in the tremor frequency range, without significantly affecting slower, voluntary movements. Testing of the digital filter was done on three patients with Parkinsonian tremor and the results compared to those of a functional electrical stimulation device based on an analog filter evaluated in a previous study. Additional testing of both the analog and digital filters was done on three subjects with no neurological impairment performing tremor-like movements and slow voluntary movements. We found that the digital controller provided a mean attenuation of 84%, compared to 65% for the analog controller.

  8. 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...

  9. Microsoft Kinect-Based Artificial Perception System for Control of Functional Electrical Stimulation Assisted Grasping

    OpenAIRE

    Matija Štrbac; Slobodan Kočović; Marko Marković; Popović, Dejan B.

    2014-01-01

    We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES) assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm ...

  10. Effectiveness of neuromuscular electrical stimulation in the functional knee rehabilitation in soldiers

    OpenAIRE

    R. Castillo-Lozano

    2015-01-01

    Background: The versatility of military physical therapist practice enables them not only to diagnose knee injuries but also to provide a wide range of definitive care and rehabilitation, reducing the need for costly evacuation. The aim this study was to evaluate the effectiveness of interventions by Neuromuscular Electrical Stimulation (NMES) in the functional knee rehabilitation in soldiers and describe the main predictors and determinants in each intervention. Methods: A systematic search ...

  11. Changes in Hyolaryngeal Movement and Swallowing Function After Neuromuscular Electrical Stimulation in Patients With Dysphagia

    OpenAIRE

    Lee, Hoo Young; Hong, Ji Seong; Lee, Kil Chan; Shin, Yoon-Kyum; Cho, Sung-Rae

    2015-01-01

    Objective To investigate immediate changes in hyolaryngeal movement and swallowing function after a cycle of neuromuscular electrical stimulation (NMES) on both submental and throat regions and submental placement alone in patients with dysphagia. Methods Fifteen patients with dysphagia were recruited. First, videofluoroscopic swallowing study (VFSS) was performed before NMES. All patients thereafter received a cycle of NMES by 2 methods of electrode placement: 1) both submental and throat re...

  12. Modulation of cell function by electric field: a high-resolution analysis.

    Science.gov (United States)

    Taghian, T; Narmoneva, D A; Kogan, A B

    2015-06-01

    Regulation of cell function by a non-thermal, physiological-level electromagnetic field has potential for vascular tissue healing therapies and advancing hybrid bioelectronic technology. We have recently demonstrated that a physiological electric field (EF) applied wirelessly can regulate intracellular signalling and cell function in a frequency-dependent manner. However, the mechanism for such regulation is not well understood. Here, we present a systematic numerical study of a cell-field interaction following cell exposure to the external EF. We use a realistic experimental environment that also recapitulates the absence of a direct electric contact between the field-sourcing electrodes and the cells or the culture medium. We identify characteristic regimes and present their classification with respect to frequency, location, and the electrical properties of the model components. The results show a striking difference in the frequency dependence of EF penetration and cell response between cells suspended in an electrolyte and cells attached to a substrate. The EF structure in the cell is strongly inhomogeneous and is sensitive to the physical properties of the cell and its environment. These findings provide insight into the mechanisms for frequency-dependent cell responses to EF that regulate cell function, which may have important implications for EF-based therapies and biotechnology development. PMID:25994294

  13. Functional electrical stimulation therapy for recovery of reaching and grasping in severe chronic pediatric stroke patients.

    Science.gov (United States)

    Kapadia, Naaz M; Nagai, Mary K; Zivanovic, Vera; Bernstein, Janet; Woodhouse, Janet; Rumney, Peter; Popovic, Milos R

    2014-04-01

    Stroke affects 2.7 children per 100,000 annually, leaving many of them with lifelong residual impairments despite intensive rehabilitation. In the present study the authors evaluated the effectiveness of 48 hours of transcutaneous functional electrical stimulation therapy for retraining voluntary reaching and grasping in 4 severe chronic pediatric stroke participants. Participants were assessed using the Rehabilitation Engineering Laboratory Hand Function Test, Quality of Upper Extremity Skills Test, Pediatric Evaluation of Disability Inventory, and Assisting Hand Assessment. All participants improved on all measures. The average change scores on selected Rehabilitation Engineering Laboratory Hand Function Test components were 14.5 for object manipulation (P = .042), 0.78 Nm for instrumented cylinder (P = .068), and 14 for wooden blocks (P = .068) and on the grasp component of Quality of Upper Extremity Skills Test was 25.93 (P = .068). These results provide preliminary evidence that functional electrical stimulation therapy has the potential to improve upper limb function in severe chronic pediatric stroke patients. PMID:23584687

  14. A multi-pad electrode based functional electrical stimulation system for restoration of grasp

    Directory of Open Access Journals (Sweden)

    Malešević Nebojša M

    2012-09-01

    Full Text Available Abstract Background Functional electrical stimulation (FES applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments.

  15. Electroencephalography(EEG)-based instinctive brain-control of a quadruped locomotion robot.

    Science.gov (United States)

    Jia, Wenchuan; Huang, Dandan; Luo, Xin; Pu, Huayan; Chen, Xuedong; Bai, Ou

    2012-01-01

    Artificial intelligence and bionic control have been applied in electroencephalography (EEG)-based robot system, to execute complex brain-control task. Nevertheless, due to technical limitations of the EEG decoding, the brain-computer interface (BCI) protocol is often complex, and the mapping between the EEG signal and the practical instructions lack of logic associated, which restrict the user's actual use. This paper presents a strategy that can be used to control a quadruped locomotion robot by user's instinctive action, based on five kinds of movement related neurophysiological signal. In actual use, the user drives or imagines the limbs/wrists action to generate EEG signal to adjust the real movement of the robot according to his/her own motor reflex of the robot locomotion. This method is easy for real use, as the user generates the brain-control signal through the instinctive reaction. By adopting the behavioral control of learning and evolution based on the proposed strategy, complex movement task may be realized by instinctive brain-control.

  16. New density functional parameterizations to accurate calculations of electric field gradient variations among compounds.

    Science.gov (United States)

    Santiago, Régis Tadeu; Haiduke, Roberto Luiz Andrade

    2015-10-30

    This research provides a performance investigation of density functional theory and also proposes new functional parameterizations to deal with electric field gradient (EFG) calculations at nuclear positions. The entire procedure is conducted within the four-component formalism. First, we noticed that traditional hybrid and long-range corrected functionals are more efficient in the description of EFG variations for a set of elements (indium, antimony, iodine, lutetium, and hafnium) among linear molecules. Thus, we selected the PBE0, B3LYP, and CAM-B3LYP functionals and promoted a reoptimization of their parameters for a better description of these EFG changes. The PBE0q variant developed here showed an overall promising performance in a validation test conducted with potassium, iodine, copper, and gold. In general, the correlation coefficients found in linear regressions between experimental nuclear quadrupole coupling constants and calculated EFGs are improved while the systematic EFG errors also decrease as a result of this reparameterization. PMID:26284820

  17. Wave function for dissipative harmonically confined electrons in a time-dependent electric field

    Science.gov (United States)

    Lai, Meng-Yun; Pan, Xiao-Yin; Li, Yu-Qi

    2016-07-01

    We investigate the many-body wave function of a dissipative system of interacting particles confined by a harmonic potential and perturbed by a time-dependent spatially homogeneous electric field. Applying the method of Yu and Sun (1994), it is found that the wave function is comprised of a phase factor times the solution to the unperturbed time-dependent (TD) Schrödinger equation with the latter being translated by a time-dependent value that satisfies the classical damped driven equation of motion, plus an addition fluctuation term due to the Brownian motion. The wave function reduces to that of the Harmonic Potential Theorem (HPT) wave function in the absence of the dissipation. An example of application of the results derived is also given.

  18. TECHNICAL NOTE: Spun-cast micromolding for etchless micropatterning of electrically functional PDMS structures

    Science.gov (United States)

    McClain, Maxine A.; La Placa, Michelle C.; Allen, Mark G.

    2009-10-01

    Polydimethylsiloxane (PDMS) is widely used in bioMEMS applications; however, patterning of this material to form complex structures is often challenging. Chemical etches are typically ineffective due to the inertness of the material. Plasma processing of bulk material can be time intensive and presents concerns regarding the mechanical properties of the post-etched polymer due to etch-induced cross-linking of surrounding material. Presented in this paper, the etchless process of spun-cast micromolding (SCμM) is used to create an array of patterned, PDMS, electrical microcables. The microcables are arranged in a net-like array and incorporate electrical functionality. The geometries fabricated with these techniques include straight and sinusoidal microcables. In addition to the cables themselves, specific regions of the cables' top insulating layer can also be patterned using a hierarchical application of the SCμM process, creating exposed electrical access sites useful as electrical access points for electrophysiological applications. The SCμM process is a simple, relatively rapid technique that can be used to make highly compliant electronic structures with patternable geometries.

  19. Restoration of Upper Limb Function in an Individual with Cervical Spondylotic Myelopathy using Functional Electrical Stimulation Therapy: A Case Study.

    Science.gov (United States)

    Popovic, Milos R; Zivanovic, Vera; Valiante, Taufik A

    2016-01-01

    Non-traumatic spinal cord pathology is responsible for 25-52% of all spinal cord lesions. Studies have revealed that spinal stenosis accounts for 16-21% of spinal cord injury (SCI) admissions. Impaired grips as well as slow unskilled hand and finger movements are the most common complaints in patients with spinal cord disorders, such as myelopathy secondary to cervical spondylosis. In the past, our team carried out couple of successful clinical trials, including two randomized control trials, showing that functional electrical stimulation therapy (FEST) can restore voluntary reaching and/or grasping function, in people with stroke and traumatic SCI. Motivated by this success, we decided to examine changes in the upper limb function following FEST in a patient who suffered loss of hand function due to myelopathy secondary to cervical spondylosis. The participant was a 61-year-old male who had C3-C7 posterior laminectomy and instrumented fusion for cervical myelopathy. The participant presented with progressive right hand weakness that resulted in his inability to voluntarily open and close the hand and to manipulate objects unilaterally with his right hand. The participant was enrolled in the study ~22 months following initial surgical intervention. Participant was assessed using Toronto Rehabilitation Institute's Hand Function Test (TRI-HFT), Action Research Arm Test (ARAT), Functional Independence Measure (FIM), and Spinal Cord Independence Measure (SCIM). The pre-post differences in scores on all measures clearly demonstrated improvement in voluntary hand function following 15 1-h FEST sessions. The changes observed were meaningful and have resulted in substantial improvement in performance of activities of daily living. These results provide preliminary evidence that FEST has a potential to improve upper limb function in patients with non-traumatic SCI, such as myelopathy secondary to cervical spondylosis. PMID:27375547

  20. Functional electrical stimulation therapy improves grasping in chronic cervical spinal cord injury: Two case studies

    Directory of Open Access Journals (Sweden)

    Miller Rosalynn C.

    2008-01-01

    Full Text Available OBJECTIVE AND IMPORTANCE: To present case studies of two individuals with chronic cervical spinal cord injury (SCI who participated in functional electrical stimulation (FES therapy with the objective to restore voluntary grasp function. CLINICAL PRESENTATION: Both individuals (right hand dominant males, age 24 and 31 had a sustained a cervical SCI (C6 and C4-5, respectively at least 8 years prior to participation in this study. INTERVENTION: Both individuals participated in an individualized FES therapy program for 6 weeks. FES therapy was administered through a regimen of three, one-hour sessions, per week for three months. A single arm of each participant (n = 2 was treated. FES therapy is an integrative intervention strategy combining muscle strengthening, functional movement training and stretching. The participant's hand movement abilities were assessed pre and post FES therapy using the Manual Muscle Test (MMT, a modified Sollerman Hand Function Test (mSHFT, and the Reach, Grasp, Transport and Release Task (RGTR. DISCUSSION: As the injuries of participants in the current study were chronic and thus neurologically stable, no spontaneous improvements/recovery in hand function was expected. However, FES as part of an integrated therapeutic approach affected restoration and improvement of hand function in both participants. CONCLUSION: The concurrent improvement in strength, integrated motor function and object contact following FES therapy, demonstrated that there is potential for affecting change in hand function of individuals with chronic SCI.

  1. Restoration of grasp following paralysis through brain-controlled stimulation of muscles

    OpenAIRE

    Ethier, C.; Oby, E.R.; Bauman, M.J.; Miller, L.E.

    2012-01-01

    Patients with spinal cord injury lack the connections between brain and spinal cord circuits essential for voluntary movement. Clinical systems that achieve muscle contraction through functional electrical stimulation (FES) have proven to be effective in allowing patients with tetraplegia to regain control of hand movement and to achieve a greater measure of independence in activities of daily living 1,2 . In typical systems, the patient uses residual proximal limb movements to trigger pre-pr...

  2. A combined DFT/Green’s function study on electrical conductivity through DNA duplex between Au electrodes

    OpenAIRE

    Tsukamoto, Takayuki; Ishikawa, Yasuyuki; Sengoku, Yasuo; Kurita, Noriyuki

    2009-01-01

    Electrical conducting properties of DNA duplexes sandwiched between Au electrodes have been investigated by use of first-principles molecular simulation based on DFT and Green’s function to elucidate the origin of their base sequence dependence. The theoretically simulated effects of DNA base sequence on the electrical conducting properties are in qualitative agreement with experiment. The HOMOs localized on Guanine bases have the major contribution to the electrical conductivity through DNA ...

  3. A combined DFT/Green’s function study on electrical conductivity through DNA duplex between Au electrodes

    Science.gov (United States)

    Tsukamoto, Takayuki; Ishikawa, Yasuyuki; Sengoku, Yasuo; Kurita, Noriyuki

    2009-06-01

    Electrical conducting properties of DNA duplexes sandwiched between Au electrodes have been investigated by use of first-principles molecular simulation based on DFT and Green's function to elucidate the origin of their base sequence dependence. The theoretically simulated effects of DNA base sequence on the electrical conducting properties are in qualitative agreement with experiment. The HOMOs localized on Guanine bases have the major contribution to the electrical conductivity through DNA duplexes.

  4. Functional Modeling of Perspectives on the Example of Electric Energy Systems

    DEFF Research Database (Denmark)

    Heussen, Kai

    2009-01-01

    The integration of energy systems is a proven approach to gain higher overall energy efficiency. Invariably, this integration will come with increasing technical complexity through the diversification of energy resources and their functionality. With the integration of more fluctuating renewable ...... which enables a reflection on system integration requirements independent of particular technologies. The results are illustrated on examples related to electric energy systems.......The integration of energy systems is a proven approach to gain higher overall energy efficiency. Invariably, this integration will come with increasing technical complexity through the diversification of energy resources and their functionality. With the integration of more fluctuating renewable...... energies higher system flexibility will also be necessary. One of the challenges ahead is the design of control architecture to enable the flexibility and to handle the diversity. This paper presents an approach to model heterogeneous energy systems and their control on the basis of purpose and functions...

  5. Electrical characterization of functionalized platinum electrodes and ISFET sensors for metal ion detection

    International Nuclear Information System (INIS)

    This paper reports the application of functionalized platinum (Pt) electrodes and ChemFETs sensors for metal ion detection. The sensitive part of the sensors consists in a film of ethyl 2-thienylglyoxalate (ETGO) deposited by a spin-coating process. Electrochemical impedance spectroscopy was used to investigate the electrical properties of functionalized Pt electrodes. The optimized working conditions of the sensors have been studied with regard to the sensitivity performances, in particular, the polarization was adjusted to - 0.85 V/ESC in order to neglect the Warburg effects at low frequencies. The functionalized Pt electrodes have shown a good sensitivity towards Cu(II) ions, whereas low response towards Ca(II) ions was observed. The ETGO/ISFET devices have shown good sensitivity (14 mV/decade) and linear responses over at least two decades of Cu(II) activity compared to (0.5 mV/decade) for Ca(II) ions

  6. Simulation of Electricity Demand Function in Agricultural Sector: An Application of Genetic Algorithm (Case Study: Electricity-Fed Wells of Iran

    Directory of Open Access Journals (Sweden)

    Hossein Sadeghi

    2014-11-01

    Full Text Available Due to several problems arisen from consumption of gas oil, it is necessary to electricity substitute fossil fuels in agriculture wells in Iran. Problems such as lack of opportune and adequate supply of fuel, air and soil pollution, noise pollution and huge costs of installation, operation and maintenance imply the necessity of replacing gas oil systems by electricity-consuming ones in agriculture sector of Iran.However, it is essential to study on the demand of electricity, nowadays, substituting other energy sources.As water wells are the main electricity consumersin agriculture sector, the estimation of energy demand function would be beneficial for policy makers to achieve their goals. The present paper investigates on energy demand function in agriculture sector of Iran.Genetic algorithm techniques are appliedto estimate electricity demand in agricultural sector in three forms: linear, quadratic and exponential equations. Based on the conventional criteria, the exponential model is selected as the best model for estimation. Furthermore, electricity demand of agricultural sector is forecasted under three scenarios for years next three years.

  7. Enhancing efficient functioning of the nordic electricity market. Summary and conclusions

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-01

    In September 2004, Nordic Council of Ministers (NCM) in their meeting in Akureyri, Iceland, assessed the state of the Nordic electricity market. The Ministers acknowledged that the market has proved it is well functioning in many respects, however, further development of the Nordic electricity market is needed, i.e. towards a regional market without borders. The Nordic Transmission System Operators (TSOs) were asked to study how a further co-ordination of the system responsibility, a joint organizing and financing of the grid investments and a handling of peak load situations can be established in the Nordic countries. In this report, the main focus is on market-related tasks within system responsibility that are market-related and may have an effect on the functioning of the market. The report covers the following issues: definition of the system responsibility and role of TSOs, harmonization of operational rules and practices in order to improve functioning of the market, TSOs' collaboration in disturbances and shortage situations and joint Nordic transmission investments. Furthermore, the report summarizes the concrete actions taken by the TSOs in strengthening of the market mechanisms in peak load situations. (BA)

  8. Electrical Properties of Conductive Cotton Yarn Coated with Eosin Y Functionalized Reduced Graphene Oxide.

    Science.gov (United States)

    Kim, Eunju; Arul, Narayanasamy Sabari; Han, Jeong In

    2016-06-01

    This study reports the fabrication and investigation of the electrical properties of two types of conductive cotton yarns coated with eosin Y or eosin B functionalized reduced graphene (RGO) and bare graphene oxide (GO) using dip-coating method. The surface morphology of the conductive cotton yarn coated with reduced graphene oxide was observed by Scanning Electron Microscope (SEM). Due to the strong electrostatic attractive forces, the negatively charged surface such as the eosin Y functionalized reduced graphene oxide or bare GO can be easily coated to the positively charged polyethyleneimine (PEI) treated cotton yarn. The maximum current for the conductive cotton yarn coated with eosin Y functionalized RGO and bare GO with 20 cycles repetition of (5D + R) process was found to be 793.8 μA and 3482.8 μA. Our results showed that the electrical conductivity of bare GO coated conductive cotton yarn increased by approximately four orders of magnitude with the increase in the dipping cycle of (5D+R) process.

  9. Enhancing efficient functioning of the nordic electricity market. Summary and conclusions

    International Nuclear Information System (INIS)

    In September 2004, Nordic Council of Ministers (NCM) in their meeting in Akureyri, Iceland, assessed the state of the Nordic electricity market. The Ministers acknowledged that the market has proved it is well functioning in many respects, however, further development of the Nordic electricity market is needed, i.e. towards a regional market without borders. The Nordic Transmission System Operators (TSOs) were asked to study how a further co-ordination of the system responsibility, a joint organizing and financing of the grid investments and a handling of peak load situations can be established in the Nordic countries. In this report, the main focus is on market-related tasks within system responsibility that are market-related and may have an effect on the functioning of the market. The report covers the following issues: definition of the system responsibility and role of TSOs, harmonization of operational rules and practices in order to improve functioning of the market, TSOs' collaboration in disturbances and shortage situations and joint Nordic transmission investments. Furthermore, the report summarizes the concrete actions taken by the TSOs in strengthening of the market mechanisms in peak load situations. (BA)

  10. Electrical Properties of Conductive Cotton Yarn Coated with Eosin Y Functionalized Reduced Graphene Oxide.

    Science.gov (United States)

    Kim, Eunju; Arul, Narayanasamy Sabari; Han, Jeong In

    2016-06-01

    This study reports the fabrication and investigation of the electrical properties of two types of conductive cotton yarns coated with eosin Y or eosin B functionalized reduced graphene (RGO) and bare graphene oxide (GO) using dip-coating method. The surface morphology of the conductive cotton yarn coated with reduced graphene oxide was observed by Scanning Electron Microscope (SEM). Due to the strong electrostatic attractive forces, the negatively charged surface such as the eosin Y functionalized reduced graphene oxide or bare GO can be easily coated to the positively charged polyethyleneimine (PEI) treated cotton yarn. The maximum current for the conductive cotton yarn coated with eosin Y functionalized RGO and bare GO with 20 cycles repetition of (5D + R) process was found to be 793.8 μA and 3482.8 μA. Our results showed that the electrical conductivity of bare GO coated conductive cotton yarn increased by approximately four orders of magnitude with the increase in the dipping cycle of (5D+R) process. PMID:27427672

  11. Calculation of the electric field inside electret ionisation chambers - Influence on the response function

    International Nuclear Information System (INIS)

    The use of electret ion chambers for gamma dose and radon exposure measurement was increasing rapidly in the last years. In contrast to conventional ion chambers, the electric field in these detectors is not constant during the exposure time. Both field-strength and direction are changing due to inhomogeneous decrease of the electret surface charges. Data of numerical field calculations inside cylindrical electret Ionisation chambers are given. The change of the field-strength distribution with respect to electret discharge is described. The influence on the response function is discussed and experimentally verified. (author)

  12. Modeling Mechanical and Electrical Uncertain Systems using Functions of Robust Control MATLAB Toolbox®3

    Directory of Open Access Journals (Sweden)

    Mohammed Tawfik Hussein

    2015-04-01

    Full Text Available Uncertainty is inherent property of all real life control systems, and this is due to that there is nothing constant practically; all parameters are going to change under some environmental circumstances, therefore control engineers must not ignore this changing since it can affect the behavior and the performance of the system. In this paper a critical research method for modeling uncertain systems is demonstrated with the utilization of built in robust control Matlab Toolbox®3 functions. Good results were obtained for testing the stability of interval linear time invariant systems. Finally mechanical and electrical uncertain systems were implemented as practical example to validate the uncertainty.

  13. Deuteron A(Q2) structure function and the neutron electric form factor

    International Nuclear Information System (INIS)

    We present new measurements of the deuteron A(Q2) structure function in the momentum transfer region between 1 and 18 fm-2. The accuracy of the data ranges from 2% to 6%. We investigate the sensitivity of A(Q2) to the nucleon-nucleon interaction and to the neutron electric form factor GEn. Our analysis shows that below 20 fm-2 GEn can be inferred from these data with a significantly improved accuracy. The model dependence of this analysis is discussed

  14. Constraining the electric dipole photon strength function in {sup 130}Te

    Energy Technology Data Exchange (ETDEWEB)

    Isaak, J.; Loeher, B.; Savran, D.; Silva, J. [ExtreMe Matter Institute EMMI and Research Division, Darmstadt (Germany); FIAS, Frankfurt (Germany); Ahmed, M.W.; Kelley, J.H.; Tornow, W.; Weller, H.R. [Department of Physics, Duke University, TUNL (United States); Beller, J.; Pietralla, N.; Romig, C.; Zweidinger, M. [Institut fuer Kernphysik, TU Darmstadt (Germany); Glorius, J.; Sonnabend, K. [Institut fuer Angewandte Physik, Goethe-Universitaet Frankfurt (Germany); Krticka, M. [Faculty of Mathematics and Physics, Charles University, Prague (Czech Republic); Rusev, G. [Chemistry Division, LANL (United States); Scheck, M. [School of Engineering, University of the West of Scotland (United Kingdom); Tonchev, A.P. [Physics Division, LLNL (United States)

    2014-07-01

    The decay properties of photo-excited states in {sup 130}Te have been investigated by means of Nuclear Resonance Fluorescence experiments at the Darmstadt High Intensity Photon Setup (DHIPS) and the High Intensity γ-ray Source (HIγS). The combination of continuous-energy bremsstrahlung on the one hand and the quasi-monoenergetic and linearly polarized photon beam on the other enables a detailed insight into the photoabsorption cross section and the decay behavior of spin-1 states. Comparing these results to simulations within the statistical model allow for constraining the electric dipole photon strength function (E1-PSF). Results are presented and discussed.

  15. Influence of laser pulse on the autocorrelation function of H in a strong electric field

    Institute of Scientific and Technical Information of China (English)

    Lifei Wang; Guangcan Yang

    2009-01-01

    The autocorrelation function of electronic wave packet of hydrogen atom in a strong electric field below the zero-field ionization threshold is investigated in the formalism of semiclassical theory. It is found that the autocorrelation depends on the applied laser pulse significantly. In the case of narrow laser pulse, the reviving peaks in the autocorrelation can be attributed to the closed orbits of electrons, which are related to the classical dynamics of the system. But this correspondence is wiped out with increasing the laser width because of the interference among the adjacent reviving peaks.

  16. Improving Balance Function Using Low Levels of Electrical Stimulation of the Balance Organs

    Science.gov (United States)

    Bloomberg, Jacob; Reschke, Millard; Mulavara, Ajitkumar; Wood, Scott; Serrador, Jorge; Fiedler, Matthew; Kofman, Igor; Peters, Brian T.; Cohen, Helen

    2012-01-01

    Crewmembers returning from long-duration space flight face significant challenges due to the microgravity-induced inappropriate adaptations in balance/sensorimotor function. The Neuroscience Laboratory at JSC is developing a method based on stochastic resonance to enhance the brain's ability to detect signals from the balance organs of the inner ear and use them for rapid improvement in balance skill, especially when combined with balance training exercises. This method involves a stimulus delivery system that is wearable/portable and provides imperceptible electrical stimulation to the balance organs of the human body. Stochastic resonance (SR) is a phenomenon whereby the response of a nonlinear system to a weak periodic input signal is optimized by the presence of a particular non-zero level of noise. This phenomenon of SR is based on the concept of maximizing the flow of information through a system by a non-zero level of noise. Application of imperceptible SR noise coupled with sensory input in humans has been shown to improve motor, cardiovascular, visual, hearing, and balance functions. SR increases contrast sensitivity and luminance detection; lowers the absolute threshold for tone detection in normal hearing individuals; improves homeostatic function in the human blood pressure regulatory system; improves noise-enhanced muscle spindle function; and improves detection of weak tactile stimuli using mechanical or electrical stimulation. SR noise has been shown to improve postural control when applied as mechanical noise to the soles of the feet, or when applied as electrical noise at the knee and to the back muscles. SR using imperceptible stochastic electrical stimulation of the vestibular system (stochastic vestibular stimulation, SVS) applied to normal subjects has shown to improve the degree of association between the weak input periodic signals introduced via venous blood pressure receptors and the heart-rate responses. Also, application of SVS over 24

  17. Semiclassical Green's function for electron motion in combined Coulomb and electric fields

    Science.gov (United States)

    Ambalampitiya, Harindranath; Fabrikant, Ilya

    2016-05-01

    We are developing an extension of the Green-function approach to the theory of ionization of a multielectron atom in a strong laser field by using the semiclassical Van Vleck-Gutzwiller propagator. For a static field the exact quantum mechanical Green's function can be calculated with an arbitrary accuracy. Therefore, as a first step towards solution of the problem, we apply the semiclassical method to the static field case for the energies above the ionization threshold where all classical trajectories contributing to the Green's function are real. Required trajectories are determined by solving the problem of finding initial velocity and traveling time corresponding to two position points. For the pure electric field case of two trajectories the semiclassical Green's function agrees very well with the exact Green's function. With the inclusion of the Coulomb field, the number of classical trajectories between two points grows rapidly and here we observe that the agreement between the semiclassical and exact Green's functions increases when more trajectories are included in the computation. Supported by the National Science Foundation.

  18. Using climate response functions in analyzing electricity production variables. A case study from Norway.

    Science.gov (United States)

    Tøfte, Lena S.; Martino, Sara; Mo, Birger

    2016-04-01

    representation of hydropower is included and total hydro power production for each area is calculated, and the production is distributed among all available plants within each area. During simulation, the demand is affected by prices and temperatures. 6 different infrastructure scenarios of wind and power line development are analyzed. The analyses are done by running EMPS calibrated for today's situation for 11*11*8 different combinations of altered weather variables (temperature, precipitation and wind) describing different climate change scenarios, finding the climate response function for every EMPS-variable according the electricity production, such as prices and income, energy balances (supply, consumption and trade), overflow losses, probability of curtailment etc .

  19. Study on Electric Double Layer of a Cylindrical Particle with Functional Theoretical Approach

    Institute of Scientific and Technical Information of China (English)

    WANG,Zheng-Wu; LIU,Xue-Min; YU,Hui-Xin; ZHOU,Ming; JIN,Jian

    2007-01-01

    A new method, i.e. the iterative method in functional theory, was introduced to solve analytically the nonlinear Poisson-Boltzmann (PB) equation under general potential ψ condition for the electric double layer of a charged cylindrical colloid particle in a symmetrical electrolyte solution. The iterative solutions of ψ are expressed as functions of the distance from the axis of the particle with solution parameters: the concentration of ions c, the aggregation number of ions in a unit length m, the dielectric constant ε, the system temperature T and so on. The relative errors show that generally only the first and the second iterative solutions can give accuracy higher than 97%. From the second iterative solution the radius and the surface potential of a cylinder have been defined and the corresponding values have been estimated with the solution parameters. Furthermore, the charge density, the activity coefficient of ions and the osmotic coefficient of solvent were also discussed.

  20. Response functions for electrically coupled neuronal network: a method of local point matching and its applications.

    Science.gov (United States)

    Yihe, Lu; Timofeeva, Yulia

    2016-06-01

    Neuronal networks connected by electrical synapses, also referred to as gap junctions, are present throughout the entire central nervous system. Many instances of gap-junctional coupling are formed between dendritic arbours of individual cells, and these dendro-dendritic gap junctions are known to play an important role in mediating various brain rhythms in both normal and pathological states. The dynamics of such neuronal networks modelled by passive or quasi-active (resonant) membranes can be described by the Green's function which provides the fundamental input-output relationships of the entire network. One of the methods for calculating this response function is the so-called 'sum-over-trips' framework which enables the construction of the Green's function for an arbitrary network as a convergent infinite series solution. Here we propose an alternative and computationally efficient approach for constructing the Green's functions on dendro-dendritic gap junction-coupled neuronal networks which avoids any infinite terms in the solutions. Instead, the Green's function is constructed from the solution of a system of linear algebraic equations. We apply this new method to a number of systems including a simple single cell model and two-cell neuronal networks. We also demonstrate that the application of this novel approach allows one to reduce a model with complex dendritic formations to an equivalent model with a much simpler morphological structure. PMID:26994016

  1. Improved estimation of electricity demand function by integration of fuzzy system and data mining approach

    International Nuclear Information System (INIS)

    This study presents an integrated fuzzy system, data mining and time series framework to estimate and predict electricity demand for seasonal and monthly changes in electricity consumption especially in developing countries such as China and Iran with non-stationary data. Furthermore, it is difficult to model uncertain behavior of energy consumption with only conventional fuzzy system or time series and the integrated algorithm could be an ideal substitute for such cases. To construct fuzzy systems, a rule base is needed. Because a rule base is not available, for the case of demand function, look up table which is one of the extracting rule methods is used to extract the rule base. This system is defined as FLT. Also, decision tree method which is a data mining approach is similarly utilized to extract the rule base. This system is defined as FDM. Preferred time series model is selected from linear (ARMA) and nonlinear model. For this, after selecting preferred ARMA model, McLeod-Li test is applied to determine nonlinearity condition. When, nonlinearity condition is satisfied, preferred nonlinear model is selected and compare with preferred ARMA model and finally one of this is selected as time series model. At last, ANOVA is used for selecting preferred model from fuzzy models and time series model. Also, the impact of data preprocessing and postprocessing on the fuzzy system performance is considered by the algorithm. In addition, another unique feature of the proposed algorithm is utilization of autocorrelation function (ACF) to define input variables, whereas conventional methods which use trial and error method. Monthly electricity consumption of Iran from 1995 to 2005 is considered as the case of this study. The MAPE estimation of genetic algorithm (GA), artificial neural network (ANN) versus the proposed algorithm shows the appropriateness of the proposed algorithm

  2. Continual electric field stimulation preserves contractile function of adult ventricular myocytes in primary culture.

    Science.gov (United States)

    Berger, H J; Prasad, S K; Davidoff, A J; Pimental, D; Ellingsen, O; Marsh, J D; Smith, T W; Kelly, R A

    1994-01-01

    To model with greater fidelity the electromechanical function of freshly isolated heart muscle cells in primary culture, we describe a technique for the continual electrical stimulation of adult myocytes at physiological frequencies for several days. A reusable plastic cover was constructed to fit standard, disposable 175-cm2 tissue culture flasks and to hold parallel graphite electrodes along the long axis of each flask, which treated a uniform electric field that resulted in a capture efficiency of ventricular myocytes of 75-80%. Computer-controlled amplifiers were designed to be capable of driving a number of flasks concurrently, each containing up to 4 x 10(6) myocytes, over a range of stimulation frequencies (from 0.1 to 7.0 Hz) with reversal of electrode polarity after each stimulus to prevent the development of pH gradients around each electrode. Unlike quiescent, unstimulated myocytes, the amplitude of contraction, and velocities of shortening and relaxation did not change in myocytes paced at 3-5 Hz for up to 72 h. The maintenance of normal contractile function in paced myocytes required mechanical contraction per se, since paced myocytes that remained quiescent due to the inclusion of 2.5 microM verapamil in the culture medium for 48 h also exhibited a decline in contractility when paced after verapamil removal. Similarly, pacing increased peak calcium current compared with quiescent cells that had not been paced. Thus myocyte contraction at physiological frequencies induced by continual uniform electric field stimulation in short-term primary culture in defining medium maintains some biophysical parameters of myocyte phenotype that are similar to those observed in freshly isolated adult ventricular myocytes.

  3. Intelligent algorithm tuning PID method of function electrical stimulation using knee joint angle.

    Science.gov (United States)

    Qiu, Shuang; He, Feng; Tang, Jiabei; Xu, Jiapeng; Zhang, Lixin; Zhao, Xin; Qi, Hongzhi; Zhou, Peng; Cheng, Xiaoman; Wan, Baikun; Ming, Dong

    2014-01-01

    Functional electrical stimulation (FES) could restore motor functions for individuals with spinal cord injury (SCI). By applying electric current pulses, FES system could produce muscle contractions, generate joint torques, and thus, achieve joint movements automatically. Since the muscle system is highly nonlinear and time-varying, feedback control is quite necessary for precision control of the preset action. In the present study, we applied two methods (Proportional Integral Derivative (PID) controller based on Back Propagation (BP) neural network and that based on Genetic Algorithm (GA)), to control the knee joint angle for the FES system, while the traditional Ziegler-Nichols method was used in the control group for comparison. They were tested using a muscle model of the quadriceps. The results showed that intelligent algorithm tuning PID controller displayed superior performance than classic Ziegler-Nichols method with constant parameters. More particularly, PID controller tuned by BP neural network was superior on controlling precision to make the feedback signal track the desired trajectory whose error was less than 1.2°±0.16°, while GA-PID controller, seeking the optimal parameters from multipoint simultaneity, resulted in shortened delay in the response. Both strategies showed promise in application of intelligent algorithm tuning PID methods in FES system.

  4. Microsoft Kinect-Based Artificial Perception System for Control of Functional Electrical Stimulation Assisted Grasping

    Directory of Open Access Journals (Sweden)

    Matija Štrbac

    2014-01-01

    Full Text Available We present a computer vision algorithm that incorporates a heuristic model which mimics a biological control system for the estimation of control signals used in functional electrical stimulation (FES assisted grasping. The developed processing software acquires the data from Microsoft Kinect camera and implements real-time hand tracking and object analysis. This information can be used to identify temporal synchrony and spatial synergies modalities for FES control. Therefore, the algorithm acts as artificial perception which mimics human visual perception by identifying the position and shape of the object with respect to the position of the hand in real time during the planning phase of the grasp. This artificial perception used within the heuristically developed model allows selection of the appropriate grasp and prehension. The experiments demonstrate that correct grasp modality was selected in more than 90% of tested scenarios/objects. The system is portable, and the components are low in cost and robust; hence, it can be used for the FES in clinical or even home environment. The main application of the system is envisioned for functional electrical therapy, that is, intensive exercise assisted with FES.

  5. The effect of Functional Electric Stimulation in stroke patients' motor control - a case report

    Science.gov (United States)

    Pripas, Denise; Rogers Venditi Beas, Allan; Fioramonte, Caroline; Gonsales de Castro, Pedro Claudio; Goroso, Daniel Gustavo; Cecília dos Santos Moreira, Maria

    2011-12-01

    Functional Electric Stimulation (FES) has been studied as a therapeutic resource to reduce spasticity in hemiplegic patients, however there are no studies about the effects of FES in motor control of these patients during functional tasks like balance maintenance. Muscular activation of gastrocnemius medialis and semitendinosus was investigated in both limbs of a hemiparetic patient during self-disturbed quiet stance before and after FES on tibialis anterior, by surface electromyography. The instant of maximum activation peak of GM and ST were calculated immediately after a motor self-disturbance, in order to observe muscular synergy between these two muscles, and possible balance strategies used (ankle or hip strategy). At the preserved limb there occurred distal-proximal synergy (GM followed by ST), expected for small perturbations; however, at spastic limb there was inversion of this synergy (proximal-distal) after FES. It is possible that intervention of electricity had inhibited synergical pathways due to antidromic effect, making it difficult to use ankle strategy in the spastic limb.

  6. Intelligent algorithm tuning PID method of function electrical stimulation using knee joint angle.

    Science.gov (United States)

    Qiu, Shuang; He, Feng; Tang, Jiabei; Xu, Jiapeng; Zhang, Lixin; Zhao, Xin; Qi, Hongzhi; Zhou, Peng; Cheng, Xiaoman; Wan, Baikun; Ming, Dong

    2014-01-01

    Functional electrical stimulation (FES) could restore motor functions for individuals with spinal cord injury (SCI). By applying electric current pulses, FES system could produce muscle contractions, generate joint torques, and thus, achieve joint movements automatically. Since the muscle system is highly nonlinear and time-varying, feedback control is quite necessary for precision control of the preset action. In the present study, we applied two methods (Proportional Integral Derivative (PID) controller based on Back Propagation (BP) neural network and that based on Genetic Algorithm (GA)), to control the knee joint angle for the FES system, while the traditional Ziegler-Nichols method was used in the control group for comparison. They were tested using a muscle model of the quadriceps. The results showed that intelligent algorithm tuning PID controller displayed superior performance than classic Ziegler-Nichols method with constant parameters. More particularly, PID controller tuned by BP neural network was superior on controlling precision to make the feedback signal track the desired trajectory whose error was less than 1.2°±0.16°, while GA-PID controller, seeking the optimal parameters from multipoint simultaneity, resulted in shortened delay in the response. Both strategies showed promise in application of intelligent algorithm tuning PID methods in FES system. PMID:25570513

  7. Effectiveness of neuromuscular electrical stimulation in the functional knee rehabilitation in soldiers

    Directory of Open Access Journals (Sweden)

    R. Castillo-Lozano

    2015-12-01

    Full Text Available Background: The versatility of military physical therapist practice enables them not only to diagnose knee injuries but also to provide a wide range of definitive care and rehabilitation, reducing the need for costly evacuation. The aim this study was to evaluate the effectiveness of interventions by Neuromuscular Electrical Stimulation (NMES in the functional knee rehabilitation in soldiers and describe the main predictors and determinants in each intervention. Methods: A systematic search of the literature about NMES in physiotherapy was performed using the following electronic databases: Web of Science, PubMed, Cochrane, Physiotherapy Evidence Database (PEDro and CINAHL. The search strategy was: "neuromuscular electrical stimulation" and "physical therapy" and "strengthening" and "knee". Inclusion criteria were: original articles published and peer reviewed between 2004-2015, focusing on physiotherapy interventions by NMES on subjects older than 18 years. A total resulting from 46 studies was included in the study. Results: The results show the evidence on the effectiveness of NMES therapeutic/preventive purposes in the muscular system; and the importance of physical therapy in the army. Conclusion: As a method of functional knee rehabilitation, NMES proves effective in achieving the therapeutic/preventive objectives in soldiers. Level of Evidence: II. Systematic review of randomized clinical trials with homogeneity.

  8. Motor cortex electrical stimulation augments sprouting of the corticospinal tract and promotes recovery of motor function

    Directory of Open Access Journals (Sweden)

    Jason B Carmel

    2014-06-01

    Full Text Available The corticospinal system—with its direct spinal pathway, the corticospinal tract (CST—is the primary system for controlling voluntary movement. Our approach to CST repair after injury in mature animals was informed by our finding that activity drives establishment of connections with spinal cord circuits during postnatal development. After incomplete injury in maturity, spared CST circuits sprout and partially restore lost function. Our approach harnesses activity to augment this injury-dependent CST sprouting and to promote function. Lesion of the medullary pyramid unilaterally eliminates all CST axons from one hemisphere and allows examination of CST sprouting from the unaffected hemisphere. We discovered that ten days of electrical stimulation of either the spared CST or motor cortex induces CST axon sprouting that partially reconstructs the lost CST. Stimulation also leads to sprouting of the cortical projection to the magnocellular red nucleus, where the rubrospinal tract originates. Coordinated outgrowth of the CST and cortical projections to the red nucleus could support partial re-establishment of motor systems connections to the denervated spinal motor circuits. Stimulation restores skilled motor function in our animal model. Lesioned animals have a persistent forelimb deficit contralateral to pyramidotomy in the horizontal ladder task. Rats that received motor cortex stimulation either after acute or chronic injury showed a significant functional improvement that brought error rate to pre-lesion control levels. Reversible inactivation of the stimulated motor cortex reinstated the impairment demonstrating the importance of the stimulated system to recovery. Motor cortex electrical stimulation is an effective approach to promote spouting of spared CST axons. By optimizing activity-dependent sprouting in animals, we could have an approach that can be translated to the human for evaluation with minimal delay.

  9. Evaluation of the brain activation induced by functional electrical stimulation and voluntary contraction using functional magnetic resonance imaging

    Directory of Open Access Journals (Sweden)

    Joa Kyung-Lim

    2012-07-01

    Full Text Available Abstract Background To observe brain activation induced by functional electrical stimulation, voluntary contraction, and the combination of both using functional magnetic resonance imaging (fMRI. Methods Nineteen healthy young men were enrolled in the study. We employed a typical block design that consisted of three sessions: voluntary contraction only, functional electrical stimulation (FES-induced wrist extension, and finally simultaneous voluntary and FES-induced movement. MRI acquisition was performed on a 3.0 T MR system. To investigate activation in each session, one-sample t-tests were performed after correcting for false discovery rate (FDR; p t-test was performed using a contrast map (p  Results In the voluntary contraction alone condition, brain activation was observed in the contralateral primary motor cortex (MI, thalamus, bilateral supplementary motor area (SMA, primary sensory cortex (SI, secondary somatosensory motor cortex (SII, caudate, and cerebellum (mainly ipsilateral. During FES-induced wrist movement, brain activation was observed in the contralateral MI, SI, SMA, thalamus, ipsilateral SII, and cerebellum. During FES-induced movement combined with voluntary contraction, brain activation was found in the contralateral MI, anterior cingulate cortex (ACC, SMA, ipsilateral cerebellum, bilateral SII, and SI. The activated brain regions (number of voxels of the MI, SI, cerebellum, and SMA were largest during voluntary contraction alone and smallest during FES alone. SII-activated brain regions were largest during voluntary contraction combined with FES and smallest during FES contraction alone. The brain activation extent (maximum t score of the MI, SI, and SII was largest during voluntary contraction alone and smallest during FES alone. The brain activation extent of the cerebellum and SMA during voluntary contraction alone was similar during FES combined with voluntary contraction; however, cerebellum and SMA activation

  10. Functional electrical stimulation-facilitated proliferation and regeneration of neural precursor cells in the brains of rats with cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    Yun Xiang; Huihua Liu; Tiebin Yan; Zhiqiang Zhuang; Dongmei Jin; Yuan Peng

    2014-01-01

    Previous studies have shown that proliferation of endogenous neural precursor cells cannot alone compensate for the damage to neurons and axons. From the perspective of neural plastici-ty, we observed the effects of functional electrical stimulation treatment on endogenous neural precursor cell proliferation and expression of basic fibroblast growth factor and epidermal growth factor in the rat brain on the infarct side. Functional electrical stimulation was performed in rat models of acute middle cerebral artery occlusion. Simultaneously, we set up a placebo stimulation group and a sham-operated group. Immunohistochemical staining showed that, at 7 and 14 days, compared with the placebo group, the numbers of nestin (a neural precursor cell marker)-positive cells in the subgranular zone and subventricular zone were increased in the functional electrical stimulation treatment group. Western blot assays and reverse-transcription PCR showed that total protein levels and gene expression of epidermal growth factor and basic ifbroblast growth factor were also upregulated on the infarct side. Prehensile traction test results showed that, at 14 days, prehension function of rats in the functional electrical stimulation group was signiifcantly better than in the placebo group. These results suggest that functional electrical stimulation can promote endogenous neural precursor cell proliferation in the brains of acute cerebral infarction rats, enhance expression of basic fibroblast growth factor and epidermal growth factor, and improve the motor function of rats.

  11. Electrical conductivity and thermal properties of functionalized carbon nanotubes/polyurethane composites

    Directory of Open Access Journals (Sweden)

    Aline M. F. Lima

    2012-01-01

    Full Text Available Multi-walled carbon nanotubes (MWCNTs functionalized with amine and carboxyl groups were used to prepare polyurethane/MWCNT nanocomposites in two distinct concentrations: a lower value of 1 mass% (spray coating and a higher one of ~50 mass% (buckypaper based. The MWCNT-NH2 sample contained only 0.5 mass% of amine groups, whereas MWCNT-COOH contained 5 mass% of carboxyl groups. The MWCNT functionalized with low amine group content showed improved thermal properties when compared to neat thermoplastic polyurethane (TPU and MWCNT-COOH based nanocomposites. The electrical conductivity of the polyurethane elastomer was greatly increased from 10-12 to ~10-5 S cm-1in the 1 mass% nanotube composite and to 7 S cm-1for the MWCNT-NH2 buckypaper-based nanocomposite. Furthermore, the relative high content of functional groups in the MWCNT-COOH sample, which disrupt the sp²structure in the nanotube walls, led to inferior properties; for instance the conductivity of the buckypaper based composite is one order of magnitude lower when using MWCNT-COOH in comparison with the MWCNT-NH2. These results show the range of property design possibilities available with the elastomeric polyurethane nanocomposite by tailoring the functional group content and the carbon nanotube load.

  12. Dual-channel functional electrical stimulation improvements in speed-based gait classifications

    Directory of Open Access Journals (Sweden)

    Springer S

    2013-02-01

    Full Text Available Shmuel Springer,1,2 Yocheved Laufer,1 Meni Becher,1,2 Jean-Jacques Vatine3,41Department of Physical Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa, 2Clinical Department, Bioness Neuromodulation, Ra'anana, 3Outpatient and Research Division, Reuth Medical Center, Tel Aviv, 4Department of Rehabilitation Medicine, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, IsraelBackground: Functional electrical stimulation (FES is becoming an accepted treatment method for enhancing gait performance in patients who present with gait difficulties resulting from hemiparesis. The purpose of this study was to test whether individuals with hemiparesis who have varied gait speeds, which place them in different functional categories, benefit to the same extent from the application of FES.Methods: Thirty-six subjects with chronic hemiparesis demonstrating foot-drop and deficits in knee and/or hip control were fitted with a dual-channel FES system activating the dorsiflexors and hamstring muscles. Gait was assessed during a 2-minute walk test with and without stimulation. A second assessment was conducted after 6 weeks of daily use. Analysis was performed with the subjects stratified into three functional ambulation classes according to their initial gait categories.Results: The dual-channel FES improved the gait velocity of all three subgroups. No minimal gait velocity was required in order to gain benefits from FES. For example, subjects with limited household ambulation capabilities improved their gait speed by 63.3% (from 0.30 ± 0.09 m/sec to 0.49 ± 0.20 m/sec; P < 0.01, while subjects with functional community ambulation capabilities improved their gait speed by 25.5% (from 0.90 ± 0.11 m/sec to 1.13 ± 0.22 m/sec; P < 0.01.Conclusion: Dual-channel FES positively affects gait velocity in patients with chronic hemiparesis, regardless of their initial gait velocity. Furthermore, gait velocity gains may be large enough

  13. Effects of motor imagery combined with functional electrical stimulation on upper limb motor function of patients with acute ischemic stroke

    Directory of Open Access Journals (Sweden)

    Shou-feng LIU

    2015-03-01

    Full Text Available Objective To explore the effects of motor imagery (MI combined with the third generation functional electrical stimulation (FES on upper limb motor function in acute ischemic stroke patients with hemiplegia.  Methods Forty acute ischemic stroke patients, within 48 h of onset, were randomly divided into FES group (N = 20 and combination group (FES combined with motor imagery, N = 20. All patients received basic routine rehabilitation training, for example, good limb positioning, accepting braces, balance training and training in the activities of daily living (ADL. FES group received the third generation FES therapy and the combination group also received motor imagery for 2 weeks. All of the patients were assessed with Fugl-Meyer Assessment (FMA, Action Research Arm Test (ARAT and active range of motion (AROM of wrist dorsiflexion before and after 2 weeks of treatment.  Results After 2 weeks of treatment, the 2 groups had significantly higher FMA score, ARAT score and AROM of wrist dorsiflexion than that in pre-treatment (P = 0.000, for all. Besides, the FMA score (t = - 2.528, P = 0.016, ARAT score (t = - 2.562, P = 0.014 and AROM of wrist dorsiflexion (t = - 2.469, P = 0.018 in the combination group were significantly higher than that in the FES group. There were interactions of treatment methods with observation time points (P < 0.05, for all.  Conclusions Motor imagery combined with the third generation FES can effectively promote the recovery of upper limb motor function and motion range of wrist dorsiflexion in patients with acute ischemic stroke. DOI: 10.3969/j.issn.1672-6731.2015.03.008

  14. Efficacy of transcutaneous functional electrical stimulation on urinary incontinence in myelomeningocele: results of a pilot study

    Directory of Open Access Journals (Sweden)

    Abdol-Mohammad Kajbafzadeh

    2010-10-01

    Full Text Available PURPOSE: To investigate the efficacy of transcutaneous functional electrical stimulation (FES on voiding symptoms in children with myelomeningocele (MMC suffering from neuropathic urinary incontinence. MATERIALS AND METHODS: Six girls and 6 boys with moderate to severe urinary incontinence secondary to MMC were included. Median age of children was 5.04 (range: 3-11 years. They underwent a urodynamic study (UDS before and 3 months after FES with special attention to detrusor leak point pressure (DLPP and maximal bladder capacity (MBC. Daily incontinence score, frequency of pad changing, and enuresis were also assessed before and three months after treatment. Fifteen courses of FES for 15 minutes 3 times per week were performed with low frequency (40 Hz electrical current, duration of 250µs, with hold and rest time of 2 seconds. RESULTS: Nine children had improvement on urinary incontinence score, while three children had no improvement. Median DLPP was significantly increased from 38.5 (range: 12-50 cm H2O to 59.5 (range: 18-83 cm H2O (P = 0.003. MBC was significantly increased from median value of 155 (range: 60-250 mL to 200 (range: 110-300 mL (P = 0.007. CONCLUSIONS: This is a pilot study showing that FES therapy might have positive effects on improvement of voiding symptoms of MMC children with neurogenic urinary incontinence in terms of daily incontinence score and UDS parameters.

  15. Polarization contributions to intermolecular interactions revisited with fragment electric-field response functions

    International Nuclear Information System (INIS)

    The polarization energy in intermolecular interactions treated by self-consistent field electronic structure theory is often evaluated using a constraint that the atomic orbital (AO) to molecular orbital transformation is blocked by fragments. This approach is tied to AO basis sets, overestimates polarization energies in the overlapping regime, particularly in large AO basis sets, and lacks a useful complete basis set limit. These problems are addressed by the construction of polarization subspaces based on the responses of isolated fragments to weak electric fields. These subspaces are spanned by fragment electric-field response functions, which can capture effects up to the dipole (D), or quadrupole (DQ) level, or beyond. Schemes are presented for the creation of both non-orthogonal and orthogonal fragment subspaces, and the basis set convergence of the polarization energies computed using these spaces is assessed. Numerical calculations for the water dimer, water–Na+, water–Mg2+, water–F−, and water–Cl− show that the non-orthogonal DQ model is very satisfactory, with small differences relative to the orthogonalized model. Additionally, we prove a fundamental difference between the polarization degrees of freedom in the fragment-blocked approaches and in constrained density schemes. Only the former are capable of properly prohibiting charge delocalization during polarization

  16. A stochastic multi-scale model of electrical function in normal and depleted ICC networks.

    Science.gov (United States)

    Gao, Jerry; Du, Peng; Archer, Rosalind; O'Grady, Greg; Gibbons, Simon J; Farrugia, Gianrico; Cheng, Leo K; Pullan, Andrew J

    2011-12-01

    Multi-scale modeling has become a productive strategy for quantifying interstitial cells of Cajal (ICC) network structure-function relationships, but the lack of large-scale ICC network imaging data currently limits modeling progress. The single normal equation simulation (SNESIM) algorithm was utilized to generate realistic virtual images of small real wild-type (WT) and 5-HT(2B)-receptor knockout (Htr2b(-/-)) mice ICC networks. Two metrics were developed to validate the performance of the algorithm: 1) network density, which is the proportion of ICC in the tissue; and 2) connectivity, which reflects the degree of connectivity of the ICC network. Following validation, the SNESIM algorithm was modified to allow variation in the degree of ICC network depletion. ICC networks from a range of depletion severities were generated, and the electrical activity over these networks was simulated. The virtual ICC networks generated by the original SNESIM algorithm were similar to that of their real counterparts. The electrical activity simulations showed that the maximum current density magnitude increased as the network density increased. In conclusion, the SNESIM algorithm is an effective tool for generating realistic virtual ICC networks. The modified SNESIM algorithm can be used with simulation techniques to quantify the physiological consequences of ICC network depletion at various physical scales.

  17. Neurotherapeutic and neuroprosthetic effects of implanted functional electrical stimulation for ambulation after incomplete spinal cord injury.

    Science.gov (United States)

    Bailey, Stephanie Nogan; Hardin, Elizabeth C; Kobetic, Rudi; Boggs, Lisa M; Pinault, Gilles; Triolo, Ronald J

    2010-01-01

    The purpose of this single-subject study was to determine the neurotherapeutic and neuroprosthetic effects of an implanted functional electrical stimulation (FES) system designed to facilitate walking in an individual with a longstanding motor and sensory incomplete spinal cord injury. An implanted pulse generator and eight intramuscular stimulating electrodes were installed unilaterally, activating weak or paralyzed hip flexors, hip and knee extensors, and ankle dorsiflexors during 36 sessions of gait training with FES. The neurotherapeutic effects were assessed by a comparison of pre- and posttraining volitional walking. The neuroprosthetic effects were assessed by a comparison of posttraining volitional and FES-assisted walking. Treatment resulted in significant (p ambulation to limited community ambulation. Additionally, the subject could perform multiple walks per day when using FES-assisted gait, which was impossible with volitional effort alone.

  18. The Effect of Aging on Erectile Function Induced by Apomorphine and Electric Field Stimulation to Rat

    Institute of Scientific and Technical Information of China (English)

    李铮; 郑松; 向祖琼; 刘勇; 王益鑫

    2002-01-01

    Objective To explore the effect and mechanism of aging on erection by using ratmodel.Materials & Methods Forty male SD rats of 3, 9, 18 and 24 months old were divid-ed into 4 groups equally according to their age. Apomorphine given subcutaneously andcavernous nerve electric field stimulation was used to induce erection of rats.Results The successful erection rate, number of erection times, and intracavernouspressure (ICP) in the rats of 18 and 24 month old was significantly lower than that of3 and 9 month old.Conclusion The erectile function in aging rats is deteriorated. The damage mecha-nism with aging might be related to dopaminergic system in central nerves.

  19. Application of the Actor-Critic Architecture to Functional Electrical Stimulation Control of a Human Arm.

    Science.gov (United States)

    Thomas, Philip; Branicky, Michael; van den Bogert, Antonie; Jagodnik, Kathleen

    2009-01-01

    Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of the actor-critic architecture, with neural networks for the both the actor and the critic, as a controller that can adapt to these changing dynamics of a human arm. Development and tests were done in simulation using a planar arm model and Hill-based muscle dynamics. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant changes to the dynamics of the arm and test the actor-critic's ability to adapt without supervision in a reasonable number of episodes. Finally, we devise methods for achieving both rapid learning and long-term stability. PMID:20689654

  20. Creating a Reinforcement Learning Controller for Functional Electrical Stimulation of a Human Arm.

    Science.gov (United States)

    Thomas, Philip S; Branicky, Michael; van den Bogert, Antonie; Jagodnik, Kathleen

    2008-01-01

    Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of Reinforcement Learning to create a controller that can adapt to these changing dynamics of a human arm. Development and tests were done in simulation using a two-dimensional arm model and Hill-based muscle dynamics. An actor-critic architecture is used with artificial neural networks for both the actor and the critic. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant changes to the dynamics of the arm and test the actor-critic's ability to adapt without supervision in a reasonable number of episodes. PMID:22081795

  1. Impact of Functional Electrical Stimulation of Lower Limbs during Sitting Pivot Transfer Motion for Paraplegic People

    Directory of Open Access Journals (Sweden)

    Jovana Jovic

    2013-01-01

    Full Text Available Individuals with Spinal Cord Injury (SCI, perform Sitting Pivot Transfer (SPT motion around fifteen times a day using upper extremities. It can lead to upper limbs pain and often shoulder complications. In this paper, we investigate the influence of Functional Electrical Stimulation (FES on SPT motion of a paraplegic person. First, we proposed to develop a dynamic optimization method in order to predict SPT motion of an able‐bodied subject. This approach has been validated by comparing the computed SPT trajectories with the ones measured during the experiment with an able‐bodied subject. Then, we used the optimization tool to analyze the influence of FES on the SPT maneuver of paraplegic persons. Our results suggest that FES can decrease arm participation during the transfer motion of a paraplegic person.

  2. Electrode Wear Prediction in Milling Electrical Discharge Machining Based on Radial Basis Function Neural Network

    Institute of Scientific and Technical Information of China (English)

    HUANG He; BAI Ji-cheng; LU Ze-sheng; GUO Yong-feng

    2009-01-01

    Milling electrical discharge machining (EDM) enables the machining of complex cavities using cylindrical or tubular electrodes. To ensure acceptable machining accuracy the process requires some methods of compensating for electrode wear. Due to the complexity and random nature of the process, existing methods of compensating for such wear usually involve off-line prediction. This paper discusses an innovative model of electrode wear prediction for milling EDM based upon a radial basis function (RBF) network. Data gained from an orthogonal experiment were used to provide training samples for the RBF network. The model established was used to forecast the electrode wear, making it possible to calculate the real-time tool wear in the milling EDM process and, to lay the foundations for dynamic compensation of the electrode wear on-line. This paper demonstrates that by using this model prediction errors can be controlled within 8%.

  3. Mechanical design and driving mechanism of an isokinetic functional electrical stimulation-based leg stepping trainer.

    Science.gov (United States)

    Hamzaid, N A; Fornusek, C; Ruys, A; Davis, G M

    2007-12-01

    The mechanical design of a constant velocity (isokinetic) leg stepping trainer driven by functional electrical stimulation-evoked muscle contractions was the focus of this paper. The system was conceived for training the leg muscles of neurologically-impaired patients. A commercially available slider crank mechanism for elliptical stepping exercise was adapted to a motorized isokinetic driving mechanism. The exercise system permits constant-velocity pedalling at cadences of 1-60 rev x min(-1). The variable-velocity feature allows low pedalling forces for individuals with very weak leg muscles, yet provides resistance to higher pedalling effort in stronger patients. In the future, the system will be integrated with a computer-controlled neuromuscular stimulator and a feedback control unit to monitor training responses of spinal cord-injured, stroke and head injury patients. PMID:18274073

  4. Electrical DNA sequencing by graphene edges functionalized with H or N atoms

    Science.gov (United States)

    Amorim, Rodrigo G.; Scheicheir, Ralph H.

    2014-03-01

    The current technology of DNA sequencing needs to be revolutionized in order to be sufficiently cost-efficient for widespread application in healthcare and genomic research. One of the most promising proposals is to use a solid-state nanodevice based on graphene due to its atomically thin edges which would readily enable single-nucleobase resolution in transverse conductance measurements. We used ab initio calculations based on Density Functional Theory combined with the non-equilibrium Green's function method to study how the capability of a graphene nanogap to electrically sense the four nucleobases (Adenine, Cytosine, Guanine and Thymine) is affected by different passivation (H or N) of the graphene edges. We will show how, for the same nucleobase, the zero bias conductance can be increased by five orders of magnitude when N atoms are chosen for functionalization over H atoms. Other aspects investigated by us concern the translational process of nucleobases through the nanogap and the corresponding spatial resolution due to diminishing transmittance as the nucleobase moves out of the gap.

  5. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; van den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-09-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action.

  6. Functional Magnetic Resonance Imaging of Electrical and Optogenetic Deep Brain Stimulation at the Rat Nucleus Accumbens

    Science.gov (United States)

    Albaugh, Daniel L.; Salzwedel, Andrew; Van Den Berge, Nathalie; Gao, Wei; Stuber, Garret D.; Shih, Yen-Yu Ian

    2016-01-01

    Deep brain stimulation of the nucleus accumbens (NAc-DBS) is an emerging therapy for diverse, refractory neuropsychiatric diseases. Although DBS therapy is broadly hypothesized to work through large-scale neural modulation, little is known regarding the neural circuits and networks affected by NAc-DBS. Using a healthy, sedated rat model of NAc-DBS, we employed both evoked- and functional connectivity (fc) MRI to examine the functional circuit and network changes achieved by electrical NAc stimulation. Optogenetic-fMRI experiments were also undertaken to evaluate the circuit modulation profile achieved by selective stimulation of NAc neurons. NAc-DBS directly modulated neural activity within prefrontal cortex and a large number of subcortical limbic areas (e.g., amygdala, lateral hypothalamus), and influenced functional connectivity among sensorimotor, executive, and limbic networks. The pattern and extent of circuit modulation measured by evoked-fMRI was relatively insensitive to DBS frequency. Optogenetic stimulation of NAc cell bodies induced a positive fMRI signal in the NAc, but no other detectable downstream responses, indicating that therapeutic NAc-DBS might exert its effect through antidromic stimulation. Our study provides a comprehensive mapping of circuit and network-level neuromodulation by NAc-DBS, which should facilitate our developing understanding of its therapeutic mechanisms of action. PMID:27601003

  7. Models of supply function equilibrium with applications to the electricity industry

    Science.gov (United States)

    Aromi, J. Daniel

    Electricity market design requires tools that result in a better understanding of incentives of generators and consumers. Chapter 1 and 2 provide tools and applications of these tools to analyze incentive problems in electricity markets. In chapter 1, models of supply function equilibrium (SFE) with asymmetric bidders are studied. I prove the existence and uniqueness of equilibrium in an asymmetric SFE model. In addition, I propose a simple algorithm to calculate numerically the unique equilibrium. As an application, a model of investment decisions is considered that uses the asymmetric SFE as an input. In this model, firms can invest in different technologies, each characterized by distinct variable and fixed costs. In chapter 2, option contracts are introduced to a supply function equilibrium (SFE) model. The uniqueness of the equilibrium in the spot market is established. Comparative statics results on the effect of option contracts on the equilibrium price are presented. A multi-stage game where option contracts are traded before the spot market stage is considered. When contracts are optimally procured by a central authority, the selected profile of option contracts is such that the spot market price equals marginal cost for any load level resulting in a significant reduction in cost. If load serving entities (LSEs) are price takers, in equilibrium, there is no trade of option contracts. Even when LSEs have market power, the central authority's solution cannot be implemented in equilibrium. In chapter 3, we consider a game in which a buyer must repeatedly procure an input from a set of firms. In our model, the buyer is able to sign long term contracts that establish the likelihood with which the next period contract is awarded to an entrant or the incumbent. We find that the buyer finds it optimal to favor the incumbent, this generates more intense competition between suppliers. In a two period model we are able to completely characterize the optimal mechanism.

  8. Functional improvement and maturation of rat and human engineered heart tissue by chronic electrical stimulation.

    Science.gov (United States)

    Hirt, Marc N; Boeddinghaus, Jasper; Mitchell, Alice; Schaaf, Sebastian; Börnchen, Christian; Müller, Christian; Schulz, Herbert; Hubner, Norbert; Stenzig, Justus; Stoehr, Andrea; Neuber, Christiane; Eder, Alexandra; Luther, Pradeep K; Hansen, Arne; Eschenhagen, Thomas

    2014-09-01

    Spontaneously beating engineered heart tissue (EHT) represents an advanced in vitro model for drug testing and disease modeling, but cardiomyocytes in EHTs are less mature and generate lower forces than in the adult heart. We devised a novel pacing system integrated in a setup for videooptical recording of EHT contractile function over time and investigated whether sustained electrical field stimulation improved EHT properties. EHTs were generated from neonatal rat heart cells (rEHT, n=96) or human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes (hEHT, n=19). Pacing with biphasic pulses was initiated on day 4 of culture. REHT continuously paced for 16-18 days at 0.5Hz developed 2.2× higher forces than nonstimulated rEHT. This was reflected by higher cardiomyocyte density in the center of EHTs, increased connexin-43 abundance as investigated by two-photon microscopy and remarkably improved sarcomere ultrastructure including regular M-bands. Further signs of tissue maturation include a rightward shift (to more physiological values) of the Ca(2+)-response curve, increased force response to isoprenaline and decreased spontaneous beating activity. Human EHTs stimulated at 2Hz in the first week and 1.5Hz thereafter developed 1.5× higher forces than nonstimulated hEHT on day 14, an ameliorated muscular network of longitudinally oriented cardiomyocytes and a higher cytoplasm-to-nucleus ratio. Taken together, continuous pacing improved structural and functional properties of rEHTs and hEHTs to an unprecedented level. Electrical stimulation appears to be an important step toward the generation of fully mature EHT.

  9. BIOMECHANICAL ANALYSYS OF LOWER EXTREMITIES DURING CONVENTIONAL AND FUNCTIONAL ELECTRICAL STIMULATION (FES) ROWING IN NON-DISABLED INDIVIDUALS

    OpenAIRE

    Takeshima, Masaaki; Shimada, Yoichi; Matsunaga, Toshiki; Iwami, Takehiro; HIRAMOTO, Kazuhiko

    2010-01-01

    Functional electrical stimulation (FES) rowing is a whole-body exercise in which the lower extremities are moved by electric stimulation and the upper extremities are moved voluntarily by paraplegics. The purpose of this study was to identify the kinematic factors of the lower extremities required to perform FES-rowing through the biomechanical analysis. Eighteen healthy adult men participated in this study. A mathematical model was developed to analyze the conventional rowing with or without...

  10. Aging assessment of Westinghouse PWR and General Electric BWR containment isolation functions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.S.; Travis, R.; Grove, E.; DiBiasio, A.

    1996-03-01

    A study was performed to assess the effects of aging on the Containment Isolation (CI) functions of Westinghouse Pressurized Water Reactors and General Electric Boiling Water Reactors. This study is part of the Nuclear Plant Aging Research (NPAR) program, sponsored by the U.S. Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. Failure data from two national databases, Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LERs), as well as plant specific data were reviewed and analyzed to understand the effects of aging on the CI functions. This study provided information on the effects of aging on component failure frequency, failure modes, and failure causes. Current inspection, surveillance, and monitoring practices were also reviewed.

  11. Event related desynchronization-modulated functional electrical stimulation system for stroke rehabilitation: A feasibility study

    Directory of Open Access Journals (Sweden)

    Takahashi Mitsuru

    2012-08-01

    Full Text Available Abstract Background We developed an electroencephalogram-based brain computer interface system to modulate functional electrical stimulation (FES to the affected tibialis anterior muscle in a stroke patient. The intensity of FES current increased in a stepwise manner when the event-related desynchronization (ERD reflecting motor intent was continuously detected from the primary cortical motor area. Methods We tested the feasibility of the ERD-modulated FES system in comparison with FES without ERD modulation. The stroke patient who presented with severe hemiparesis attempted to perform dorsiflexion of the paralyzed ankle during which FES was applied either with or without ERD modulation. Results After 20 minutes of training, the range of movement at the ankle joint and the electromyography amplitude of the affected tibialis anterior muscle were significantly increased following the ERD-modulated FES compared with the FES alone. Conclusions The proposed rehabilitation technique using ERD-modulated FES for stroke patients was feasible. The system holds potentials to improve the limb function and to benefit stroke patients.

  12. Aging assessment of Westinghouse PWR and General Electric BWR containment isolation functions

    International Nuclear Information System (INIS)

    A study was performed to assess the effects of aging on the Containment Isolation (CI) functions of Westinghouse Pressurized Water Reactors and General Electric Boiling Water Reactors. This study is part of the Nuclear Plant Aging Research (NPAR) program, sponsored by the U.S. Nuclear Regulatory Commission. The objectives of this program are to provide an understanding of the aging process and how it affects plant safety so that it can be properly managed. This is one of a number of studies performed under the NPAR program which provide a technical basis for the identification and evaluation of degradation caused by age. Failure data from two national databases, Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LERs), as well as plant specific data were reviewed and analyzed to understand the effects of aging on the CI functions. This study provided information on the effects of aging on component failure frequency, failure modes, and failure causes. Current inspection, surveillance, and monitoring practices were also reviewed

  13. ALTERATION OF MUSCLE FUNCTION AFTER ELECTRICAL STIMULATION BOUT OF KNEE EXTENSORS AND FLEXORS

    Directory of Open Access Journals (Sweden)

    Marc Vanderthommen

    2012-12-01

    Full Text Available The purpose was to study the effects on muscle function of an electrical stimulation bout applied unilaterally on thigh muscles in healthy male volunteers. One group (ES group, n = 10 received consecutively 100 isometric contractions of quadriceps and 100 isometric contractions of hamstrings (on-off ratio 6-6 s induced by neuromuscular electrical stimulations (NMES. Changes in muscle torque, muscle soreness (0-10 VAS, muscle stiffness and serum creatine kinase (CK activity were assessed before the NMES exercise (pre-ex as well as 24h (d+1, 48h (d+2 and 120h (d+5 after the bout. A second group (control group, n = 10 were submitted to the same test battery than the ES group and with the same time-frame. The between-group comparison indicated a significant increase in VAS scores and in serum levels of CK only in the ES group. In the ES group, changes were more pronounced in hamstrings than in quadriceps and peaked at d+2 (quadriceps VAS scores = 2.20 ± 1.55 a.u. (0 at pre-ex; hamstrings VAS scores = 3.15 ± 2.14 a.u. (0 at pre-ex; hip flexion angle = 62 ± 5° (75 ± 6° at pre-ex; CK activity = 3021 ± 2693 IU·l-1 (136 ± 50 IU·l-1 at pre-ex. The results of the present study suggested the occurrence of muscle damage that could have been induced by the peculiar muscle recruitment in NMES and the resulting overrated mechanical stress. The sensitivity to the damaging effects of NMES appeared higher in the hamstrings than in quadriceps muscles

  14. The electricity exchange. On the organisation and latent functions of electricity exchange trading as seen from the viewpoint of market sociology; Die Stromboerse. Ueber Form und latente Funktionen des boerslichen Stromhandels aus marktsoziologischer Sicht

    Energy Technology Data Exchange (ETDEWEB)

    Giacovelli, Sebastian

    2014-07-01

    Electricity exchange trading in Germany has existed since the year 2000. Since this time, the Leipzig electricity exchange, a reference market for off-exchange electricity trading, has operated in an environment marked by both criticism and acceptance. Taking this field of controversy as a point of departure the present empirical study in market sociology undertakes to investigate the organisation and latent functions of electricity exchange trading. The ensuing analysis provides answers to questions as to how prices are formed on the electricity exchange and what officially incommunicable functions are served by price formation on exchanges.

  15. Electrical stimulation accelerates nerve regeneration and functional recovery in delayed peripheral nerve injury in rats.

    Science.gov (United States)

    Huang, Jinghui; Zhang, Yongguang; Lu, Lei; Hu, Xueyu; Luo, Zhuojing

    2013-12-01

    The present study aims to investigate the potential of brief electrical stimulation (ES; 3 V, 20 Hz, 20 min) in improving functional recovery in delayed nerve injury repair (DNIR). The sciatic nerve of Sprague Dawley rats was transected, and the repair of nerve injury was delayed for different time durations (2, 4, 12 and 24 weeks). Brief depolarizing ES was applied to the proximal nerve stump when the transected nerve stumps were bridged with a hollow nerve conduit (5 mm in length) after delayed periods. We found that the diameter and number of regenerated axons, the thickness of myelin sheath, as well as the number of Fluoro-Gold retrograde-labeled motoneurons and sensory neurons were significantly increased by ES, suggesting that brief ES to proximal nerve stumps is capable of promoting nerve regeneration in DNIR with different delayed durations, with the longest duration of 24 weeks. In addition, the amplitude of compound muscle action potential (gastrocnemius muscle) and nerve conduction velocity were also enhanced, and gastrocnemius muscle atrophy was partially reversed by brief ES, indicating that brief ES to proximal nerve stump was able to improve functional recovery in DNIR. Furthermore, brief ES was capable of increasing brain-derived neurotrophic factor (BDNF) expression in the spinal cord in DNIR, suggesting that BDNF-mediated neurotrophin signaling might be one of the contributing factors to the beneficial effect of brief ES on DNIR. In conclusion, the present findings indicate the potential of using brief ES as a useful method to improve functional recovery for delayed repair of peripheral nerve lesions. PMID:24118464

  16. Electrical conductivity of mantle clinopyroxene as a function of water content and its implication on electrical structure of uppermost mantle

    Science.gov (United States)

    Zhao, Chengcheng; Yoshino, Takashi

    2016-08-01

    The electrical conductivity of San Carlos clinopyroxene aggregates with various water contents were measured under Ni-NiO buffer at 1.5 GPa and 600-1200 K in a DIA-type apparatus. The conductivity increases with increasing water content in clinopyroxene. Hidden conduction mechanism was detected because of the much smaller iron content in clinopyroxene, which was usually covered by small polaron conduction in other nominally anhydrous minerals. The identified activation enthalpies ranged from 0.70-0.75 eV to 1.23-1.37 eV. Our result reveals that the dominant charge-carrying species in electrical conductivity could change with temperature and water content. At high temperatures relevant to asthenospheric condition, activation enthalpy for the conductivity agrees well with that for the hydrogen self-diffusion. The dominant charge carrier therefore might be M site vacancy. However, contrary to previous view that all hydrogens contribute to increasing conductivity equally, our result shows that only a limited amount (20%-40%) of hydrogen acts as effective charge carrier in clinopyroxene. On the other hand, the activation enthalpy for the conductivity at low temperatures is significantly lower than that for the hydrogen self-diffusion, similar to what has been observed in olivine and orthopyroxene. This type of conduction is probably caused by fast diffusion of specific hydrogen or fast hydrogen grain boundary diffusion. At low temperatures, the proton conduction of clinopyroxene is nearly one order and two orders of magnitude lower than those of olivine and orthopyroxene, respectively, and tends to converge at high temperatures. Using the present data combined with conductivity of olivine and orthopyroxene, a laboratory-based conductivity-depth profile in the uppermost mantle shows that hydrous clinopyroxene cannot account for the high conductive regions observed beneath the ocean floor near Eastern Pacific Rise. The presence of partial melt would be unavoidable.

  17. Wave-function Visualization of Core-induced Interaction of Non-hydrogenic Rydberg Atom in Electric Field

    CERN Document Server

    Gao, W; Cheng, H; Zhang, S S; Liu, H P

    2015-01-01

    We have investigated the wave-function feature of Rydberg sodium in a uniform electric field and found that the core-induced interaction of non-hydrogenic atom in electric field can be directly visualized in the wave-function. As is well known, the hydrogen atom in electric field can be separated in parabolic coordinates (\\eta, \\xi), whose eigen-function can show a clear pattern towards negative and positive directions corresponding to the so-called red and blue states without ambiguity, respectively. It can be served as a complete orthogonal basis set to study the core-induced interaction of non-hydrogenic atom in electric field. Owing to complete different patterns of the probability distribution for red and blue states, the interaction can be visualized in the wave-function directly via superposition. Moreover, the constructive and destructive interferences between red and blue states are also observed in the wave-function, explicitly explaining the experimental measurement for the spectral oscillator stre...

  18. Analytic investigation of effect of electric field on elasto-plastic response of a functionally graded piezoelectric hollow sphere

    Energy Technology Data Exchange (ETDEWEB)

    Atai, Ali Asghar [University of Tehran, Tehran (Iran, Islamic Republic of); Lak, Davaod [National Iranian Oil Co., Tehran (Iran, Islamic Republic of)

    2016-01-15

    In this work, the effect of electric potential on the mechanical (Stresses, strains, displacement) and electrical (electrical displacement and intensity) response of a Functionally graded piezoelectric (FGP) hollow sphere is analytically investigated. The sphere is under the action of internal/external pressure and temperature gradient as well. The inhomogeneity is based on power law in radial direction. The analysis is done in two parts: elastic response and plastic response, using Tresca yield criterion. It is shown by illustrative example that under internal pressure and assumed model parameters, the commencement of plastic region is from outside surface towards inside in the plastic zone is extended with the increase of electric potential. Interestingly, radial stress and displacement have an extreme not on the boundaries, but on the inside.

  19. Density Functional Theory in High Energy Density Physics: phase-diagram and electrical conductivity of water

    Science.gov (United States)

    Mattsson, Thomas R.

    2007-06-01

    Atomistic simulations employing Density Functional Theory (DFT) have recently emerged as a powerful way of increasing our understanding of materials and processes in high energy density physics. Knowledge of the properties of water (equation of state, electrical conductivity, diffusion, low-energy opacity) is essential for correctly describing the physics of giant planets as well as shock waves in water. Although a qualitative picture of water electrical conductivity has emerged, the necessary quantitative information is scarce over a wide range of temperature and density. Since experiments can only access certain areas of phase space, and often require modeling as a part of the analysis, Quantum Molecular Dynamics simulations play a vital role. Using finite-temperature density functional theory (FT-DFT), we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/ superionic/ electronic liquid). The ionic contribution to the conduction is calculated from proton diffusion and the electronic contribution is calculated using the Kubo-Greenwood formula. The calculations are performed with VASP, a plane-wave pseudo-potential code. There is a rapid transition to ionic conduction at 2000 K and 2 g/cm^3, whereas electronic conduction dominates at temperatures at and above 6000 K&[tilde;1]. Contrary to earlier results using the Car-Parrinello method&[tilde;2], we predict that the fluid bordering the superionic phase is conducting above 4000 K and 100 GPa. Our comprehensive use of FT-DFT explains the new findings. The calculated conductivity is compared to experimental data. I gratefully acknowledge Mike Desjarlais, my collaborator in this effort. The LDRD office at Sandia supported this work. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL

  20. Effect of a 2-Week Trial of Functional Electrical Stimulation on Gait Function and Quality of Life in People with Multiple Sclerosis

    OpenAIRE

    Downing, Abbey; Van Ryn, David; Fecko, Anne; Aiken, Christopher; McGowan, Sean; Sawers, Sarah; McInerny, Thomas; Moore, Katie; Passariello, Louis; Rogers, Helen

    2014-01-01

    Background: Footdrop is a common gait deviation in people with multiple sclerosis (MS) leading to impaired gait and balance as well as decreased functional mobility. Functional electrical stimulation (FES) provides an alternative to the current standard of care for footdrop, an ankle-foot orthosis (AFO). FES stimulates the peroneal nerve and activates the dorsiflexor muscles, producing an active toe clearance and a more normal gait. This study was undertaken to determine the effects of a 2-we...

  1. Early Poststroke Rehabilitation Using a Robotic Tilt-Table Stepper and Functional Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Alexey N. Kuznetsov

    2013-01-01

    Full Text Available Background. Stroke frequently leaves survivors with hemiparesis. To prevent persistent deficits, rehabilitation may be more effective if started early. Early training is often limited because of orthostatic reactions. Tilt-table stepping robots and functional electrical stimulation (FES may prevent these reactions. Objective. This controlled convenience sample study compares safety and feasibility of robotic tilt-table training plus FES (ROBO-FES and robotic tilt-table training (ROBO against tilt-table training alone (control. A preliminary assessment of efficacy is performed. Methods. Hemiparetic ischemic stroke survivors (age years, days after stroke were assigned to 30 days of ROBO-FES (, ROBO (, or control ( in addition to conventional physical therapy. Impedance cardiography and transcranial doppler sonography were performed before, during, and after training. Hemiparesis was assessed using the British Medical Research Council (MRC strength scale. Results. No serious adverse events occurred; 8 patients in the tilt-table group prematurely quit the study because of orthostatic reactions. Blood pressure and CBFV dipped % during robot training. In 52% of controls mean arterial pressure decreased by %. ROBO-FES increased leg strength by points, ROBO by more than control (, . CBFV increased in both robotic groups more than in controls (. Conclusions. Robotic tilt-table exercise with or without FES is safe and may be more effective in improving leg strength and cerebral blood flow than tilt table alone.

  2. Novel Walking Stability-Based Gait Recognition Method for Functional Electrical Stimulation System Control

    Institute of Scientific and Technical Information of China (English)

    MING Dong; WAN Baikun; HU Yong; WANG Yan; WANG Weijie; WU Yinghua; LU Dieji

    2007-01-01

    Gait recognition is the key question of functional electrical stimulation (FES) system control for paraplegic walking. A new risk-tendency-graph (RTG) method was proposed to recognize the stability information in FES-assisted walking gait. The main instrument was a specialized walker dynamometer system based on a multi-channel strain-gauge bridge network fixed on the walker frame. During walking process, this system collected the reaction forces between patient's upper extremities and walker and converted them into RTG morphologic curves of dynamic gait stability in temporal and spatial domains.To demonstrate the potential usefulness of RTG, preliminary clinical trials were done with paraplegic patients. The gait stability levels of two walking cases with 4- and 12-week FES training from one subject were quantified (0.43 and 0.19) from the results of temporal and spatial RTG. Relevant instable phases in gait cycle and dangerous inclinations of patient's body during walking process were also brought forward. In conclusion, the new RTG method is practical for distinguishing more useful gait stability information for FES system control.

  3. Gait phase detection from sciatic nerve recordings in functional electrical stimulation systems for foot drop correction.

    Science.gov (United States)

    Chu, Jun-Uk; Song, Kang-Il; Han, Sungmin; Lee, Soo Hyun; Kang, Ji Yoon; Hwang, Dosik; Suh, Jun-Kyo Francis; Choi, Kuiwon; Youn, Inchan

    2013-05-01

    Cutaneous afferent activities recorded by a nerve cuff electrode have been used to detect the stance phase in a functional electrical stimulation system for foot drop correction. However, the implantation procedure was difficult, as the cuff electrode had to be located on the distal branches of a multi-fascicular nerve to exclude muscle afferent and efferent activities. This paper proposes a new gait phase detection scheme that can be applied to a proximal nerve root that includes cutaneous afferent fibers as well as muscle afferent and efferent fibers. To test the feasibility of this scheme, electroneurogram (ENG) signals were measured from the rat sciatic nerve during treadmill walking at several speeds, and the signal properties of the sciatic nerve were analyzed for a comparison with kinematic data from the ankle joint. On the basis of these experiments, a wavelet packet transform was tested to define a feature vector from the sciatic ENG signals according to the gait phases. We also propose a Gaussian mixture model (GMM) classifier and investigate whether it could be used successfully to discriminate feature vectors into the stance and swing phases. In spite of no significant differences in the rectified bin-integrated values between the stance and swing phases, the sciatic ENG signals could be reliably classified using the proposed wavelet packet transform and GMM classification methods.

  4. Gait phase detection from sciatic nerve recordings in functional electrical stimulation systems for foot drop correction

    International Nuclear Information System (INIS)

    Cutaneous afferent activities recorded by a nerve cuff electrode have been used to detect the stance phase in a functional electrical stimulation system for foot drop correction. However, the implantation procedure was difficult, as the cuff electrode had to be located on the distal branches of a multi-fascicular nerve to exclude muscle afferent and efferent activities. This paper proposes a new gait phase detection scheme that can be applied to a proximal nerve root that includes cutaneous afferent fibers as well as muscle afferent and efferent fibers. To test the feasibility of this scheme, electroneurogram (ENG) signals were measured from the rat sciatic nerve during treadmill walking at several speeds, and the signal properties of the sciatic nerve were analyzed for a comparison with kinematic data from the ankle joint. On the basis of these experiments, a wavelet packet transform was tested to define a feature vector from the sciatic ENG signals according to the gait phases. We also propose a Gaussian mixture model (GMM) classifier and investigate whether it could be used successfully to discriminate feature vectors into the stance and swing phases. In spite of no significant differences in the rectified bin-integrated values between the stance and swing phases, the sciatic ENG signals could be reliably classified using the proposed wavelet packet transform and GMM classification methods. (paper)

  5. A New system for Measuring Electrical Conductivity of Water as a Function of Admittance

    Directory of Open Access Journals (Sweden)

    Haval Yacoob

    2011-12-01

    Full Text Available This paper presents a new system for measuring water conductivity as a function of electrophysical property (admittance. The system is cheap and its manufacturing is easy. In addition, it dose not require any sort of electrolysis and calibration. The system consists of four electrodes made of silver (Ag 92.5 g to Cu 7.5 g fixed in a plastic tube filled by water which allows the use of two and four electrode setups. The admittance (reciprocal of impedance is measured for different water sources (distilled, rainfall, mineral, river and tap water using different frequencies between 50 Hz and 100 kHz. These measurements were taken twice, once with four electrodes and another with two electrodes of two modes (inner and outer electrodes. The results have shown good correlation between the measured admittance and the conductivity of all the water sources and the best correlation was found at low frequencies between 50 Hz and 20 kHz. The highest efficiency can be achieved by performing the four electrodes system which allows circumventing the effect of the electrode impedance. This result makes the system efficient compared to traditional conductivity meters which usually require high frequencies for good operation. doi:10.5617/jeb.203 J Electr Bioimp, vol. 2, pp. 86-92, 2011

  6. Electromagnetic Processing of Materials Materials Processing by Using Electric and Magnetic Functions

    CERN Document Server

    Asai, Shigeo

    2012-01-01

    This book is both a course book and a monograph. In fact, it has developed from notes given to graduate course students on materials processing in the years 1989 to 2006. Electromagnetic Processing of Materials (EPM), originates from a branch of materials science and engineering developed in the 1980s as a field aiming to create new materials and/or design processes by making use of various functions which appear when applying the electric and magnetic fields to materials. It is based on transport phenomena, materials processing and magnetohydrodynamics. The first chapter briefly introduces the history, background and technology of EPM. In the second chapter, the concept of transport phenomena is concisely introduced and in the third chapter the essential part of magnetohydrodynamics is transcribed and readers are shown that the concept of transport phenomena does not only apply to heat, mass and momentum, but also magnetic field. The fourth chapter describes electromagnetic processing of electrica...

  7. Evaluation of Functional Electrical Stimulation to Assist Cycling in Four Adolescents with Spastic Cerebral Palsy

    Directory of Open Access Journals (Sweden)

    Ann Tokay Harrington

    2012-01-01

    Full Text Available Introduction. Adolescents with cerebral palsy (CP often have difficulty participating in exercise at intensities necessary to improve cardiovascular fitness. Functional electrical stimulation- (FES- assisted cycling is proposed as a form of exercise for adolescents with CP. The aims of this paper were to adapt methods and assess the feasibility of applying FES cycling technology in adolescents with CP, determine methods of performing cycling tests in adolescents with CP, and evaluate the immediate effects of FES assistance on cycling performance. Materials/Methods. Four participants (12–14 years old; GMFCS levels III-IV participated in a case-based pilot study of FES-assisted cycling in which bilateral quadriceps muscles were activated using surface electrodes. Cycling cadence, power output, and heart rate were collected. Results. FES-assisted cycling was well tolerated (n=4 and cases are presented demonstrating increased cadence (2–43 rpm, power output (19–70%, and heart rates (4-5% and decreased variability (8–13% in cycling performance when FES was applied, compared to volitional cycling without FES assistance. Some participants (n=2 required the use of an auxiliary hub motor for assistance. Conclusions. FES-assisted cycling is feasible for individuals with CP and may lead to immediate improvements in cycling performance. Future work will examine the potential for long-term fitness gains using this intervention.

  8. Neurotherapeutic and neuroprosthetic effects of implanted functional electrical stimulation for ambulation after incomplete spinal cord injury

    Directory of Open Access Journals (Sweden)

    Ronald J. Triolo, PhD

    2010-03-01

    Full Text Available The purpose of this single-subject study was to determine the neurotherapeutic and neuroprosthetic effects of an implanted functional electrical stimulation (FES system designed to facilitate walking in an individual with a long-standing motor and sensory incomplete spinal cord injury. An implanted pulse generator and eight intramuscular stimulating electrodes were installed unilaterally, activating weak or paralyzed hip flexors, hip and knee extensors, and ankle dorsiflexors during 36 sessions of gait training with FES. The neurotherapeutic effects were assessed by a comparison of pre- and posttraining volitional walking. The neuroprosthetic effects were assessed by a comparison of posttraining volitional and FES-assisted walking. Treatment resulted in significant (p < 0.005 volitional improvements in 6-minute walking distance and speed, speed during maximum walk, double support time, and 10 m walking speed. Posttraining FES-assisted walking resulted in significant additional improvements in all these measures, except 10 m walking speed. When the subject was using FES-assisted gait, maximum walking distance, peak knee flexion in swing, peak ankle dorsiflexion in swing, and knee extension moment also significantly increased. Neuroprosthetic gains were sufficient to enable the subject to advance from household ambulation to limited community ambulation. Additionally, the subject could perform multiple walks per day when using FES-assisted gait, which was impossible with volitional effort alone.

  9. Improving respiration in patients with tetraplegia by functional electrical stimulation: an anatomical perspective.

    Science.gov (United States)

    Bell, Sarah; Shaw-Dunn, John; Gollee, Henrik; Allan, David B; Fraser, Matthew H; McLean, Alan N

    2007-08-01

    Patients with tetraplegia often have respiratory complications because of paralysis of the abdominal and intercostal muscles. Functional electrical stimulation (FES) has been used to improve breathing in these patients by applying surface stimulation to the abdominal muscles. We aimed to find the best nerves to stimulate directly to increase tidal volume and make cough more effective. Surface electrodes were placed on a patient's abdominal wall to find the optimum points for surface stimulation. These positions were plotted on a transparent sheet. The abdomino-intercostal nerves were dissected in five male dissecting room cadavers matched for size with the patient. The plastic sheet was then superimposed over each of the dissections to clarify the relationship between optimum surface stimulation points and the underlying nerves. Results show that the optimum surface stimulation points overlie the course of abdomino-intercostal nerves T9, 10, and 11. The success with selecting stimulation points associated with T9, 10, and 11 is probably because of the large mass of abdominal muscle supplied by these nerves. The constant position of the nerves below the ribs makes the intercostal space a possible site for direct stimulation of the abdomino-intercostal nerves.

  10. Model-based imaging of cardiac electrical function in human atria

    Science.gov (United States)

    Modre, Robert; Tilg, Bernhard; Fischer, Gerald; Hanser, Friedrich; Messnarz, Bernd; Schocke, Michael F. H.; Kremser, Christian; Hintringer, Florian; Roithinger, Franz

    2003-05-01

    Noninvasive imaging of electrical function in the human atria is attained by the combination of data from electrocardiographic (ECG) mapping and magnetic resonance imaging (MRI). An anatomical computer model of the individual patient is the basis for our computer-aided diagnosis of cardiac arrhythmias. Three patients suffering from Wolff-Parkinson-White syndrome, from paroxymal atrial fibrillation, and from atrial flutter underwent an electrophysiological study. After successful treatment of the cardiac arrhythmia with invasive catheter technique, pacing protocols with stimuli at several anatomical sites (coronary sinus, left and right pulmonary vein, posterior site of the right atrium, right atrial appendage) were performed. Reconstructed activation time (AT) maps were validated with catheter-based electroanatomical data, with invasively determined pacing sites, and with pacing at anatomical markers. The individual complex anatomical model of the atria of each patient in combination with a high-quality mesh optimization enables accurate AT imaging, resulting in a localization error for the estimated pacing sites within 1 cm. Our findings may have implications for imaging of atrial activity in patients with focal arrhythmias.

  11. Volatility transmission and volatility impulse response functions in European electricity forward markets

    Energy Technology Data Exchange (ETDEWEB)

    Le Pen, Yannick [Institut d' Economie et de Management de Nantes - IAE, Universite de Nantes, Chemin de la Censive du Tertre, BP 52231, 44322 Nantes cedex 3 (France); Sevi, Benoit [Universite d' Angers (GRANEM), Faculte de Droit, Economie et Gestion, Universite d' Angers, 13 allee Francois Mitterrand, BP 13633, 49036 Angers cedex 01 (France)

    2010-07-15

    Using daily data from March 2001 to June 2005, we estimate a VAR-BEKK model and find evidence of return and volatility spillovers between the German, the Dutch and the British forward electricity markets. We apply Hafner and Herwartz [2006, Journal of International Money and Finance 25, 719-740] Volatility Impulse Response Function (VIRF) to quantify the impact of shock on expected conditional volatility. We observe that a shock has a high positive impact only if its size is large compared to the current level of volatility. The impact of shocks are usually not persistent, which may be a consequence of the non-storability of power. Finally, we estimate the density of the VIRF at different forecast horizons. These fitted distributions are asymmetric and show that large increases in expected conditional volatilities are possible even if their probability is low. These results have interesting implications for market participants whose risk management policy depends on option prices which themselves depend on the characteristics of volatility. (author)

  12. Effects of Dual-Channel Functional Electrical Stimulation on Gait Performance in Patients with Hemiparesis

    Directory of Open Access Journals (Sweden)

    Shmuel Springer

    2012-01-01

    Full Text Available The study objective was to assess the effect of functional electrical stimulation (FES applied to the peroneal nerve and thigh muscles on gait performance in subjects with hemiparesis. Participants were 45 subjects (age 57.8 ± 14.8 years with hemiparesis (5.37 ± 5.43 years since diagnosis demonstrating a foot-drop and impaired knee control. Thigh stimulation was applied either to the quadriceps or hamstrings muscles, depending on the dysfunction most affecting gait. Gait was assessed during a two-minute walk test with/without stimulation and with peroneal stimulation alone. A second assessment was conducted after six weeks of daily use. The addition of thigh muscles stimulation to peroneal stimulation significantly enhanced gait velocity measures at the initial and second evaluation. Gait symmetry was enhanced by the dual-channel stimulation only at the initial evaluation, and single-limb stance percentage only at the second assessment. For example, after six weeks, the two-minute gait speed with peroneal stimulation and with the dual channel was 0.66 ± 0.30 m/sec and 0.70 ± 0.31 m/sec, respectively (. In conclusion, dual-channel FES may enhance gait performance in subjects with hemiparesis more than peroneal FES alone.

  13. Non parametric forecasting of functional-valued processes: application to the electricity load

    International Nuclear Information System (INIS)

    This thesis addresses the problem of predicting a functional valued stochastic process. We first explore the model proposed by Antoniadis et al. (2006) in the context of a practical application -the french electrical power demand- where the hypothesis of stationarity may fail. The departure from stationarity is twofold: an evolving mean level and the existence of groups that may be seen as classes of stationarity. We explore some corrections that enhance the prediction performance. The corrections aim to take into account the presence of these nonstationary features. In particular, to handle the existence of groups, we constraint the model to use only the data that belongs to the same group of the last available data. If one knows the grouping, a simple post-treatment suffices to obtain better prediction performances. If the grouping is unknown, we propose it from data using clustering analysis. The infinite dimension of the not necessarily stationary trajectories have to be taken into account by the clustering algorithm. We propose two strategies for this, both based on wavelet transforms. The first one uses a feature extraction approach through the Discrete Wavelet Transform combined with a feature selection algorithm to select the significant features to be used in a classical clustering algorithm. The second approach clusters directly the functions by means of a dissimilarity measure of the Continuous Wavelet spectra.The third part of thesis is dedicated to explore an alternative prediction model that incorporates exogenous information. For this purpose we use the framework given by the Autoregressive Hilbertian processes. We propose a new class of processes that we call Conditional Autoregressive Hilbertian (carh) and develop the equivalent of projection and resolvent classes of estimators to predict such processes. (author)

  14. Volitional cycling augmented by functional electrical stimulation in hemiparetic adolescents: A case series study

    Directory of Open Access Journals (Sweden)

    Peri Elisabetta

    2013-01-01

    Full Text Available The aim of this work was to assess the feasibility of a treatment based on volitional cycling augmented by Functional Electrical Stimulation (FES on hemiparetic adolescents. Six chronic hemiparetic adolescents were included in a case series study. Patients underwent FES-cycling training combined with voluntary pedaling. The intervention consisted of 21 sessions lasting 30 minutes each. Patients were evaluated before, after training, and at a 3-month follow-up visit through clinical scales (Winter scale, observational gait scale, gross motor function measurement, Boyd test and Ashworth scale, a standard gait analysis and a voluntary pedaling test. Results were compared with an age-matched healthy control group (N=6. Two subjects withdrew the study before the completion of the intervention. Concerning the four remaining subjects, the clinical scales showed a slight level of disability already at baseline and no changes were observed after the intervention. In terms of walking ability, some significant improvements (Kruskal-Wallis test, p-value<0.05 were obtained after training in two out of four subjects: an increase of about 16% and 41% of the ankle range of motion and of about 18% and 33% of the ankle propelling power were achieved for two subjects, respectively. During pedaling, the work produced by the paretic leg while pulling the pedal significantly increased in 3 out of 4 subjects. In one subject a more symmetrical cycling movement was observed, whilst for another subject a significant improvement in terms of co-contraction between rectus femoris and biceps femoris was achieved. In conclusion, this study assessed the feasibility of FES-cycling training on hemiparetic adolescents, but did not provide evidences about the effectiveness of this intervention in improving motor recovery and walking ability. However, since only a small group of patients with a low level of disability was involved in the study, further investigations are needed to

  15. Analysis Of Functional Stability Of The Triphased Asynchronous Generator Used In Conversion Systems Of A Eolian Energy Into Electric Energy

    Directory of Open Access Journals (Sweden)

    Ion VONCILA

    2003-12-01

    Full Text Available This paper presents a study of the influence of the main perturbation agent over the functional stability of the triphased asynchronous generator (for the two alternative: with coiled and short circuit rotor, used for the conversion systems from a eolian energy into electric energy.

  16. Effects of preoperative neuromuscular electrical stimulation on quadriceps strength and functional recovery in total knee arthroplasty. A pilot study.

    LENUS (Irish Health Repository)

    Walls, Raymond J

    2010-01-01

    Supervised preoperative muscle strengthening programmes (prehabilitation) can improve recovery after total joint arthroplasty but are considered resource intensive. Neuromuscular electrical stimulation (NMES) has been shown to improve quadriceps femoris muscle (QFM) strength and clinical function in subjects with knee osteoarthritis (OA) however it has not been previously investigated as a prehabilitation modality.

  17. A functional legal design for reliable electricity supply. How technology affects law. Report VI

    International Nuclear Information System (INIS)

    The liberalisation and international integration of electricity markets have led to a dramatic increase in the complexity of the electricity sector. Rather than hierarchical control, it is the legal framework (rules of the game that determines the behaviour of actors such as power generators, traders and network operators). Because of the unusual technical and economic characteristics of electricity markets, their performance is very sensitive to the formulation of the legal framework. Still, a structured approach to formulating the legal framework has not yet been developed. This book meets this demand. Many questions need to be answered in the design of a legal framework for the electricity industry and often they are interdependent. This study proposes a design method for the analysis and design of the legal organisation of a technically complex sector such as the electricity industry. The method takes into account the relevant policy goals, legal constraints and technical characteristics. While the method is developed for electricity markets, it can be applied to other technically complex infrastructures as well. The proposed method is applied to several critical cases, such as the security of electricity supply, operational security in large networks, congestion management and the question how to deal with merchant transmission investment. In addition to validating the proposed method, these case studies offer a wealth of practical information about the policy choices for restructuring the electricity industry. This makes this book a rich resource for anyone interested in the design of electricity markets

  18. Therapeutic efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease

    OpenAIRE

    Ya-mei RAN; Lin, Ling; Yu-qin HE; Chen, Qiang; Ji, Lei; Xiu-qiong LANG; Huang, Zhi-yong; YANG, MIN

    2015-01-01

    Objective To study the clinical efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease, and its effects on mental health and life-quality of the patients. Methods According to the Rome Ⅲ criteria and Montreal consensus in diagnosis of gastroesophageal reflux disease, 50 patients with concomitant refractory functional dyspepsia and non-erosive reflux disease were recruited. The clinical efficacy of digital music gastr...

  19. Monitoring muscle metabolic indexes by time-domain near infrared spectroscopy during knee flex-extension induced by functional electrical stimulation

    Science.gov (United States)

    Torricelli, Alessandro; Contini, Davide; Spinelli, Lorenzo; Cubeddu, Rinaldo; Molteni, Franco; Ferrante, Simona; Pedrocchi, Alessandra; Ferrigno, Giancarlo

    2007-07-01

    A time-domain NIRS multichannel system was used to monitor hemodynamic changes in the muscle of volunteers and hemiplegic patients during functional electrical stimulation for rehabilitation purposes.

  20. Electrical Grid Conditioning For First NPP Integration, a Systems Engineering Approach Incorporating Quality Function Deployment

    Energy Technology Data Exchange (ETDEWEB)

    Pwani, Henry; James, J. [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    Nuclear power plant has a high potential to cause serious harm to environment as evidenced by effects of Fukushima and Chernobyl accidents. A reliable electrical power is required for a NPP to facilitate cooling after a shutdown. Failure of electrical power supply during shutdown increases core damage probability. Research shows that a total of 39% of LOOP related events in US are electrical grid centered. In Korea, 38% and 29% of all events that led to NPP shutdown at Hanul units 3-6 and at Hanbit units 3-6 respectively were electrical related. Electric grids for both operating and new NPPs must therefore be examined and upgraded for reliability improvement in order to enhance NPP safety.

  1. Electricity economics

    CERN Document Server

    Hu, Zhaoguang

    2013-01-01

    Systematically analyzing for the first time the production output from electricity consumption for enterprises, sectors, and industries, this study uses the function of EAI (electricity as input), and includes national E-GDP figures for more than 20 countries.

  2. Effects of Electric Stimulations Applied during Absolute Refractory Period on Cardiac Function of Rabbits with Heart Failure

    Institute of Scientific and Technical Information of China (English)

    张海柱; 崔长琮; 胡大一

    2010-01-01

    The effects of electric currents applied during absolute refractory period(ARP) on the cardiac function of rabbits with heart failure due to myocardial infarction(MI),and the safety of this method were investigated.Thirty rabbits were randomly assigned equally to 3 groups:sham-operated group,LV-anterior wall cardiac contractility modulation(LV-CCM) group,and septum-CCM(S-CCM) group.A thoracotomy was performed on all the rabbits.Electric pulses were delivered during the ARP on the anterior wall of left ventr...

  3. Dynamics of completely unfolded and native proteins through solid-state nanopores as a function of electric driving force.

    Science.gov (United States)

    Oukhaled, Abdelghani; Cressiot, Benjamin; Bacri, Laurent; Pastoriza-Gallego, Manuela; Betton, Jean-Michel; Bourhis, Eric; Jede, Ralf; Gierak, Jacques; Auvray, Loïc; Pelta, Juan

    2011-05-24

    We report experimentally the dynamic properties of the entry and transport of unfolded and native proteins through a solid-state nanopore as a function of applied voltage, and we discuss the experimental data obtained as compared to theory. We show an exponential increase in the event frequency of current blockades and an exponential decrease in transport times as a function of the electric driving force. The normalized current blockage ratio remains constant or decreases for folded or unfolded proteins, respectively, as a function of the transmembrane potential. The unfolded protein is stretched under the electric driving force. The dwell time of native compact proteins in the pore is almost 1 order of magnitude longer than that of unfolded proteins, and the event frequency for both protein conformations is low. We discuss the possible phenomena hindering the transport of proteins through the pores, which could explain these anomalous dynamics, in particular, electro-osmotic counterflow and protein adsorption on the nanopore wall.

  4. Conducted electrical weapon incapacitation during a goal-directed task as a function of probe spread.

    Science.gov (United States)

    Ho, Jeffrey; Dawes, Donald; Miner, James; Kunz, Sebastian; Nelson, Rebecca; Sweeney, James

    2012-12-01

    Despite training and field experience that the location and spread between conducted electrical weapon (CEW) probes is important in establishing incapacitation, there have been no human studies which have systematically examined the relationships between probe spread and incapacitation. We have investigated this relationship with the TASER(®) X26. We have also developed and validated methodologies for prospective assessment of the effectiveness of CEWs in the incapacitation of highly motivated human subjects. Subjects (n = 30) had probes placed on the front or back with randomly varied spreads in accordance with recommended targeting zones. Subjects were motivated to complete the task of disabling the device or a dummy officer suspended ten feet away during the exposure while using a training knife. Subjects were rated on their progress toward goal success and on the extent of any incapacitation using two separate observer scoring panels: one consisting of experts in physiology and X26 technology, and another of veteran peace officers. Incapacitation by all measures was found to be a function of spread; generally increasing in effectiveness up to spreads between 9 and 12 in. There were notable differences between front and back exposures, with front exposures not leading to full incapacitation of the upper extremities regardless of probe spread. This is the first published study on a quantitative methodology for directly assessing the effectiveness of CEWs in human incapacitation. We have also validated and quantified for the first time in human subjects that establishing a minimal spread between X26 probes correlates to the extent of device effectiveness. PMID:22610783

  5. Vertical electric field stimulated neural cell functionality on porous amorphous carbon electrodes.

    Science.gov (United States)

    Jain, Shilpee; Sharma, Ashutosh; Basu, Bikramjit

    2013-12-01

    We demonstrate the efficacy of amorphous macroporous carbon substrates as electrodes to support neuronal cell proliferation and differentiation in electric field mediated culture conditions. The electric field was applied perpendicular to carbon substrate electrode, while growing mouse neuroblastoma (N2a) cells in vitro. The placement of the second electrode outside of the cell culture medium allows the investigation of cell response to electric field without the concurrent complexities of submerged electrodes such as potentially toxic electrode reactions, electro-kinetic flows and charge transfer (electrical current) in the cell medium. The macroporous carbon electrodes are uniquely characterized by a higher specific charge storage capacity (0.2 mC/cm(2)) and low impedance (3.3 kΩ at 1 kHz). The optimal window of electric field stimulation for better cell viability and neurite outgrowth is established. When a uniform or a gradient electric field was applied perpendicular to the amorphous carbon substrate, it was found that the N2a cell viability and neurite length were higher at low electric field strengths (≤ 2.5 V/cm) compared to that measured without an applied field (0 V/cm). While the cell viability was assessed by two complementary biochemical assays (MTT and LDH), the differentiation was studied by indirect immunostaining. Overall, the results of the present study unambiguously establish the uniform/gradient vertical electric field based culture protocol to either enhance or to restrict neurite outgrowth respectively at lower or higher field strengths, when neuroblastoma cells are cultured on porous glassy carbon electrodes having a desired combination of electrochemical properties.

  6. Converting chemical energy into electricity through a functionally cooperating device with diving-surfacing cycles.

    Science.gov (United States)

    Song, Mengmeng; Cheng, Mengjiao; Ju, Guannan; Zhang, Yajun; Shi, Feng

    2014-11-01

    A smart device that can dive or surface in aqueous medium has been developed by combining a pH-responsive surface with acid-responsive magnesium. The diving-surfacing cycles can be used to convert chemical energy into electricity. During the diving-surfacing motion, the smart device cuts magnetic flux lines and produces a current, demonstrating that motional energy can be realized by consuming chemical energy of magnesium, thus producing electricity. PMID:25146589

  7. Local changes of work function near rough features on Cu surfaces operated under high external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Djurabekova, Flyura, E-mail: flyura.djurabekova@helsinki.fi; Ruzibaev, Avaz; Parviainen, Stefan [Helsinki Institute of Physics and Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 Helsinki (Finland); Holmström, Eero [Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki (Finland); Department of Earth Sciences, Faculty of Maths and Physical Sciences, UCL Earth Sciences, Gower Street, London WC1E 6BT (United Kingdom); Hakala, Mikko [Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki (Finland)

    2013-12-28

    Metal surfaces operated under high electric fields produce sparks even if they are held in ultra high vacuum. In spite of extensive research on the topic of vacuum arcs, the mystery of vacuum arc origin still remains unresolved. The indications that the sparking rates depend on the material motivate the research on surface response to extremely high external electric fields. In this work by means of density-functional theory calculations we analyze the redistribution of electron density on (100) Cu surfaces due to self-adatoms and in presence of high electric fields from −1 V/nm up to −2 V/nm (−1 to −2 GV/m, respectively). We also calculate the partial charge induced by the external field on a single adatom and a cluster of two adatoms in order to obtain reliable information on charge redistribution on surface atoms, which can serve as a benchmarking quantity for the assessment of the electric field effects on metal surfaces by means of molecular dynamics simulations. Furthermore, we investigate the modifications of work function around rough surface features, such as step edges and self-adatoms.

  8. The development and evaluation of functional electrical stimulation rowing for health, exercise and sport for persons with spinal cord injury

    OpenAIRE

    Hettinga, Dries Martijn

    2006-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. At the beginning of this project it was known that functional electrical stimulation (FES) rowing was technically feasible, but no studies on health benefits had been conducted and it was unclear what levels of fitness could be reliably attained by spinal cord injured (SCI) users. This thesis shows that training with the first-generation of the FES-rowing system (RowStim II), seven paraplegic...

  9. Optimum Dispatch of Hybrid Solar Thermal (HSTP Electric Power Plant Using Non-Smooth Cost Function and Emission Function for IEEE-30 Bus System

    Directory of Open Access Journals (Sweden)

    Saroj Kumar Dash

    2016-07-01

    Full Text Available The basic objective of economic load dispatch (ELD is to optimize the total fuel cost of hybrid solar thermal electric power plant (HSTP. In ELD problems the cost function for each generator has been approximated by a single quadratic cost equation. As cost of coal increases, it becomes even more important have a good model for the production cost of each generator for the solar thermal hybrid system. A more accurate formulation is obtained for the ELD problem by expressing the generation cost function as a piece wise quadratic cost function. However, the solution methods for ELD problem with piece wise quadratic cost function requires much complicated algorithms such as the hierarchical structure approach along with evolutionary computations (ECs. A test system comprising of 10 units with 29 different fuel [7] cost equations is considered in this paper. The applied genetic algorithm method will provide optimal solution for the given load demand.

  10. Updated greenhouse gas and criteria air pollutant emission factors and their probability distribution functions for electricity generating units

    Energy Technology Data Exchange (ETDEWEB)

    Cai, H.; Wang, M.; Elgowainy, A.; Han, J. (Energy Systems)

    2012-07-06

    Greenhouse gas (CO{sub 2}, CH{sub 4} and N{sub 2}O, hereinafter GHG) and criteria air pollutant (CO, NO{sub x}, VOC, PM{sub 10}, PM{sub 2.5} and SO{sub x}, hereinafter CAP) emission factors for various types of power plants burning various fuels with different technologies are important upstream parameters for estimating life-cycle emissions associated with alternative vehicle/fuel systems in the transportation sector, especially electric vehicles. The emission factors are typically expressed in grams of GHG or CAP per kWh of electricity generated by a specific power generation technology. This document describes our approach for updating and expanding GHG and CAP emission factors in the GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation) model developed at Argonne National Laboratory (see Wang 1999 and the GREET website at http://greet.es.anl.gov/main) for various power generation technologies. These GHG and CAP emissions are used to estimate the impact of electricity use by stationary and transportation applications on their fuel-cycle emissions. The electricity generation mixes and the fuel shares attributable to various combustion technologies at the national, regional and state levels are also updated in this document. The energy conversion efficiencies of electric generating units (EGUs) by fuel type and combustion technology are calculated on the basis of the lower heating values of each fuel, to be consistent with the basis used in GREET for transportation fuels. On the basis of the updated GHG and CAP emission factors and energy efficiencies of EGUs, the probability distribution functions (PDFs), which are functions that describe the relative likelihood for the emission factors and energy efficiencies as random variables to take on a given value by the integral of their own probability distributions, are updated using best-fit statistical curves to characterize the uncertainties associated with GHG and CAP emissions in life

  11. Interaction of electrical stimulation and voluntary hand movement in SII and the cerebellum during simulated therapeutic functional electrical stimulation in healthy adults.

    Science.gov (United States)

    Iftime-Nielsen, Simona Denisia; Christensen, Mark Schram; Vingborg, Rune Jersin; Sinkjaer, Thomas; Roepstorff, Andreas; Grey, Michael James

    2012-01-01

    The therapeutic application of functional electrical stimulation (FES) has shown promising clinical results in the rehabilitation of post-stroke hemiplegia. It appears that the effect is optimal when the patterned electrical stimulation is used in close synchrony with voluntary movement, although the neural mechanisms that underlie the clinical successes reported with therapeutic FES are unknown. One possibility is that therapeutic FES takes advantage of the sensory consequences of an internal model. Here, we investigate fMRI cortical activity when FES is combined with voluntary effort (FESVOL) and we compare this activity to that produced when FES and voluntary activity (VOL) are performed alone. FESVOL revealed greater cerebellar activity compared with FES alone and reduced activity bilaterally in secondary somatosensory areas (SII) compared with VOL alone. Reduced activity was also observed for FESVOL compared with FES alone in the angular gyrus, middle frontal gyrus and inferior frontal gyrus. These findings indicate that during the VOL condition the cerebellum predicts the sensory consequences of the movement and this reduces the subsequent activation in SII. The decreased SII activity may reflect a better match between the internal model and the actual sensory feedback. The greater cerebellar activity coupled with reduced angular gyrus activity in FESVOL compared with FES suggests that the cortex may interpret sensory information during the FES condition as an error-like signal due to the lack of a voluntary component in the movement.

  12. Development of Electric Cart with Function of Maintaining/Improving Exercise Ability—Part I: Design of the Electric Cart System—

    Science.gov (United States)

    Ohyama, Yasuhiro; She, Jin-Hua; Kobayashi, Hiroyuki; Naemura, Kiyoshi

    This paper explains the development of a three-wheeled electric cart that not only is a means of transportation, but also provides the driver with a way of getting some physical exercise. Based on an investigation of the physiological decline accompanying aging, pedaling was chosen to implement the function of maintaining or improving physical strength; and an ergonomically designed pedal unit was mounted on a cart. An interface board that handles inputs and outputs was assembled to simplify the design of the system. Finally, a simple bilateral master-slave control system was built to test the cart. Experimental results on a fabricated cart demonstrate the effectiveness of pedaling and the usability of the system structure.

  13. Insulating function in electrical equipments; Fonction isolation dans les materiels electriques

    Energy Technology Data Exchange (ETDEWEB)

    Pinel, B.; Duchateau, F. [Electricite de France (EDF), 75 - Paris (France). Groupe d' etudes au service Materiel electrique de la Div. Recherche et Developpement

    1999-11-01

    Materials have played a preponderant role in the improvements made on electrical equipments. Insulating materials can be of various composition (polymers, glass, ceramics, wood, paper, cardboard, oil, air, vacuum, gas..) and available under various states (solid, liquid, gaseous). The electrical insulation is of prime importance in power production, transport and distribution equipments. This paper presents first the stresses that can act on insulation systems and their influence on the behaviour of materials. Then, the classes of evolution of insulation systems are described with the characterisation, testing and modeling of insulating materials. The following aspects are reviewed successively: 1 - design and use stresses encountered in electrical equipments (electrical, thermal, mechanical, climatic, and radiation stresses, safety, environment); 2 - the design of an insulation system: basic materials, examples of evolutions and designs (from mixed to dry insulation, environment and insulating materials, from liquid to gaseous dielectric materials, synthetic materials and the replacement of mineral materials); 3 - evaluation of stresses resistance: general aspects, testing methods (diagnosis methods, evaluation of stresses during operation), environmental impact, case studies (external insulation and tracers, modeling of power cables with a synthetic insulation, complete forecasting approach of cables in nuclear power plants). (J.S.)

  14. Response of the Shockley surface state to an external electrical field: A density-functional theory study of Cu(111)

    Science.gov (United States)

    Berland, K.; Einstein, T. L.; Hyldgaard, P.

    2012-01-01

    The response of the Cu(111) Shockley surface state to an external electrical field is characterized by combining a density-functional theory calculation for a slab geometry with an analysis of the Kohn-Sham wave functions. Our analysis is facilitated by a decoupling of the Kohn-Sham states via a rotation in Hilbert space. We find that the surface state displays isotropic dispersion, quadratic until the Fermi wave vector but with a significant quartic contribution beyond. We calculate the shift in energetic position and effective mass of the surface state for an electrical field perpendicular to the Cu(111) surface; the response is linear over a broad range of field strengths. We find that charge transfer occurs beyond the outermost copper atoms and that accumulation of electrons is responsible for a quarter of the screening of the electrical field. This allows us to provide well converged determinations of the field-induced changes in the surface state for a moderate number of layers in the slab geometry.

  15. A New Method to Optimize Semiactive Hybrid Energy Storage System for Hybrid Electrical Vehicle by Using PE Function

    Directory of Open Access Journals (Sweden)

    Cong Zhang

    2015-01-01

    Full Text Available Although both battery and super-capacitor are important power sources for hybrid electric vehicles, there is no accurate configuration theory to match the above two kinds of power sources which have significantly different characteristics on energy and power storage for the goal of making good use of their individual features without size wasting. In this paper, a new performance is presented that is used for analysis and optimal design method of battery and super-capacitor for hybrid energy storage system of a parallel hybrid electrical vehicle. In order to achieve optimal design with less consumption, the power-energy function is applied to establish direct mathematical relationship between demand power and the performance. During matching process, firstly, three typical operating conditions are chosen as the basis of design; secondly, the energy and power capacity evaluation methods for the parameters of battery and super-capacitor in hybrid energy storage system are proposed; thirdly, the mass, volume, and cost of the system are optimized simultaneously by using power-energy function. As a result, there are significant advantages on mass, volume, and cost for the hybrid energy storage system with the matching method. Simulation results fit well with the results of analysis, which confirms that the optimized design can meet the demand of hybrid electric vehicle well.

  16. Computer Simulation Tests of Feedback Error Learning Controller with IDM and ISM for Functional Electrical Stimulation in Wrist Joint Control

    Directory of Open Access Journals (Sweden)

    Takashi Watanabe

    2010-01-01

    Full Text Available Feedforward controller would be useful for hybrid Functional Electrical Stimulation (FES system using powered orthotic devices. In this paper, Feedback Error Learning (FEL controller for FES (FEL-FES controller was examined using an inverse statics model (ISM with an inverse dynamics model (IDM to realize a feedforward FES controller. For FES application, the ISM was tested in learning off line using training data obtained by PID control of very slow movements. Computer simulation tests in controlling wrist joint movements showed that the ISM performed properly in positioning task and that IDM learning was improved by using the ISM showing increase of output power ratio of the feedforward controller. The simple ISM learning method and the FEL-FES controller using the ISM would be useful in controlling the musculoskeletal system that has nonlinear characteristics to electrical stimulation and therefore is expected to be useful in applying to hybrid FES system using powered orthotic device.

  17. Improving Electrical Impedance Tomography of brain function with a novel servo-controlled electrode helmet

    OpenAIRE

    Avery, J. P.

    2015-01-01

    Electrical Impedance Tomography (EIT) is a medical imaging technique which reconstructs the internal conductivity of an object from boundary measurements. EIT has the potential to provide a novel means of imaging in acute stroke, epilepsy or traumatic brain injury. Previous studies, whilst demonstrating the potential of the technique, have not been successful clinically.The work in this thesis aims to address fundamental limitations including measurement drift in electronic hardware, lack of ...

  18. Label-free electrical biosensing based on electrochemically functionalized carbon nanostructures

    OpenAIRE

    Kurkina, Tetiana

    2012-01-01

    The development of new analytical approaches in the diagnostics of the diseases with higher throughput, smaller sample and set-up sizes, lower cost and easier disposal is one of the major needs of modern medicine. Miniaturization and simplification of biomedical assays are required for point of care diagnostics and lab-on-a-chip systems. In this thesis the concept of electrical biosensors based on single wall carbon nanotubes (SWCNTs) and graphene is presented. The detection of saccharides an...

  19. Photovoltaic Power System with MPPT Functionality for a Small-Size Electric Vehicle

    OpenAIRE

    Jianming Xu; Longyun Kang; Changyi Zhong; Binggang Cao

    2014-01-01

    Electric vehicles are recognized as the best replacement of petrol vehicles in the future. However, there are several problems hampering their development, such as the short life span of batteries, poor performance of start-up, and a short driving range. In order to resolve these problems, a hybrid power system based on photovoltaic (PV) cells, supercapacitors, and batteries is proposed. This paper focuses on PV cells using a maximum power point track (MPPT) system based on a BUCK chopper cir...

  20. Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

    OpenAIRE

    Gabriele Fisichella; Salvatore Di Franco; Patrick Fiorenza; Raffaella Lo Nigro; Fabrizio Roccaforte; Cristina Tudisco; Condorelli, Guido G; Nicolò Piluso; Noemi Spartà; Stella Lo Verso; Corrado Accardi; Cristina Tringali; Sebastiano Ravesi; Filippo Giannazzo

    2013-01-01

    Chemical vapour deposition (CVD) on catalytic metals is one of main approaches for high-quality graphene growth over large areas. However, a subsequent transfer step to an insulating substrate is required in order to use the graphene for electronic applications. This step can severely affect both the structural integrity and the electronic properties of the graphene membrane. In this paper, we investigated the morphological and electrical properties of CVD graphene transferred onto SiO2 and o...

  1. The effects of ankle joint muscle strengthening and proprioceptive exercise programs accompanied by functional electrical stimulation on stroke patients' balance.

    Science.gov (United States)

    Kim, Kyunghoon; Lee, Sukmin; Kim, Donghoon; Kim, Kyou Sik

    2015-09-01

    [Purpose] The purpose of the present study was to examine the effects of ankle joint muscle strengthening and proprioceptive exercises accompanied by functional electrical stimulation on stroke patients' balance ability. [Methods] For six weeks beginning in April 2015, 22 stroke patients receiving physical therapy at K Hospital located in Gyeonggi-do were divided into a functional electrical stimulation (FES), ankle proprioceptive exercise and ankle joint muscle strengthening exercise group (FPS group) of 11 patients and an FES and stretching exercise group (FS group) of 11 patients. The stimulation and exercises were conducted for 30 min per day, five days per week for six weeks. Balance ability was measured using a BioRescue and the Berg balance scale, functional reach test, and the timed up-and-go test were also used as clinical evaluation indices. Repeated measures ANOVA was conducted to examine differences between before the exercises and at three and six weeks after beginning the exercises within each group, and the amounts of change between the two groups were compared. [Results] In the comparison within each group, both groups showed significant differences between before and after the experiment in all the tests and comparison between the groups showed that greater improvement was seen in all values in the FPS group. [Conclusion] In the present study, implementing FES and stretching exercises plus ankle joint muscle strengthening and proprioceptive exercises was more effective at improving stroke patients balance ability than implementing only FES and stretching exercises.

  2. Therapeutic efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease

    Directory of Open Access Journals (Sweden)

    Ya-mei RAN

    2015-04-01

    Full Text Available Objective To study the clinical efficacy of digital music gastric electrical pacing for refractory functional dyspepsia concomitant with non-erosive reflux disease, and its effects on mental health and life-quality of the patients. Methods According to the Rome Ⅲ criteria and Montreal consensus in diagnosis of gastroesophageal reflux disease, 50 patients with concomitant refractory functional dyspepsia and non-erosive reflux disease were recruited. The clinical efficacy of digital music gastric electrical pacing were evaluated using the score of clinical symptoms before treatment and 15 days after treatment, and the mental health and life-quality of patients were assessed using symptom checklist 90. Results Main symptoms, including upper abdominal pain, abdominal fullness, early satiety, belching, hiccup, nausea, heartburn, acid reflux (daytime, nocturnal acid reflux, loss of appetite and sleep, were significantly improved 15 days after treatment compared with those of pre-treatment, and there were statistically significant differences (all P<0.005. The significant response rate/response rate (efficacy rate were 59.0%/100.0%, 59.3%/96.3%, 47.0%/94.1%, 61.3%/96.8 %, 86.7%/100.0%, 80.0%/100.0%, 64.3%/92.9%, 73.7%/89.5%, 64.3%/85.7%, 90.0%/90.0%, 36.7%/93.3% respectively. After treatment for 15 days, the overall response rate of symptom relief was 94.4% in patients and the overall significant response rate was 65.7%. The symptom scores of somatization, obsessive-compulsiveness, depression, and anxiety were significantly improved, and the differences were statistically significant (all P<0.01. Conclusion The clinical efficacy of digital music gastric electrical pacing is significant for refractory functional dyspepsia concomitant with nonerosive reflux disease, and it is expected to be a new option for the treatment of this disease complex. DOI: 10.11855/j.issn.0577-7402.2015.03.08

  3. Electrical and optical characterization of DNA molecules as a function of concentration in aqueous solution

    Science.gov (United States)

    Polcari, A.; Romano, P.; Sabatino, L.; Vecchio, E. del; Consales, M.; Cusano, A.; Cutolo, A.; Colantuoni, V.

    2011-04-01

    We present experimental data on the electrical and optical behavior of circular and linear plasmid DNA molecules embedded in an aqueous matrix. From the electrical point of view, the results indicate that the presence of water is essential when the DNA concentration is not sufficient to ensure conduction patterns, consistent with the conduction mechanisms proposed for DNA molecules. In fact, as droplets are layered on the substrate, a nonlinear behavior of the current-voltage curves is observed; when water evaporates, the conductivity decreases to a very low value that resembles the high resistivity of the substrate. As more droplets are added, the current increases giving higher conductivity, as expected, since more molecules participate into the conduction process. The conduction behavior of DNA could be due to a tunneling transport of charges inside the molecule, the tunneling barrier being the adenine-thymine bridge between consecutive guanine-cytosine base pairs. A hopping channel, activated by the water surrounding the molecules, could act as an additional mechanism between different molecules. Optical reflectance measurements, performed in the wavelength range 230-450 nm on dried samples, obtained by complete evaporation of the aqueous matrix containing plasmid DNA under UV-VIS light, reveal absorption in the wavelength range 230-300 nm, typical of DNA-based materials. Moreover, in correspondence of the absorption region, the higher the DNA concentration, the higher the reflectance reduction. This suggests that the DNA concentration strongly influences the spectral behavior of biological layers. Finally, we present preliminary results exploiting the possibility to control the morphological and optical features of DNA layers by means of proper lighting procedures. Both electrical and optical measurements indicate that the DNA concentration is a crucial parameter for technical applications. The results reported here provide a contribution for the possible use

  4. Functional Changes in the Care-needing Elderly after Surface Electrical Stimulation to the Abdomen

    OpenAIRE

    Miura, Misa; Seki, Kazunori; Ito, Osamu; Handa, Yasunobu; Kohzuki, Masahiro

    2012-01-01

    Background: Strength of the trunk muscles is a key component of motor control, but it declines easily with the process of aging and/or disuse. Objectives: To investigate the effects of surface electrical stimulation (ES) to the abdominal muscles and the motor performance for care-needing elderly. Design: Controlled trial. Participants: Twenty-one elderly people (60–90 years) with care-needing, who were admitted to a nursing home or hospital for daily care and their score of Barthel Index had ...

  5. Exploring nanoscale electrical and electronic properties of organic and polymeric functional materials by atomic force microscopy based approaches.

    Science.gov (United States)

    Palermo, Vincenzo; Liscio, Andrea; Palma, Matteo; Surin, Mathieu; Lazzaroni, Roberto; Samorì, Paolo

    2007-08-28

    Beyond imaging, atomic force microscopy (AFM) based methodologies enable the quantitative investigation of a variety of physico-chemical properties of (multicomponent) materials with a spatial resolution of a few nanometers. This Feature Article is focused on two AFM modes, i.e. conducting and Kelvin probe force microscopies, which allow the study of electrical and electronic properties of organic thin films, respectively. These nanotools provide a wealth of information on (dynamic) characteristics of tailor-made functional architectures, opening pathways towards their technological application in electronics, catalysis and medicine.

  6. Multi-functional Converter with Integrated Motor Control, Battery Charging and Active Module Balancing for Electric Vehicular Application

    DEFF Research Database (Denmark)

    Mathe, Laszlo; Schaltz, Erik; Teodorescu, Remus;

    2014-01-01

    In order to reduce the fuel consumption and the acoustical noise generated by refuse lorries, electrification of the waste compactor unit is a very promising solution. For the electrical energy storage Lithium-Sulfur (Li-S) battery technology has been selected with potential for reducing the cost...... used successfully in HVDC/FACTS and large drive applications. In this paper the use of MMC for a battery driven waste compactor unit addressed with integrated functionality including: motor driver, battery charge and active balancing is presented. The challenges addressed here are related to the design...

  7. Road load simulator tests of the Gould phase 1 functional model silicon controlled rectifier ac motor controller for electric vehicles

    Science.gov (United States)

    Gourash, F.

    1984-02-01

    The test results for a functional model ac motor controller for electric vehicles and a three-phase induction motor which were dynamically tested on the Lewis Research Center road load simulator are presented. Results show that the controller has the capability to meet the SAE-J227a D cycle test schedule and to accelerate a 1576-kg (3456-lb) simulated vehicle to a cruise speed of 88.5 km/hr (55 mph). Combined motor controller efficiency is 72 percent and the power inverter efficiency alone is 89 percent for the cruise region of the D cycle. Steady state test results for motoring, regeneration, and thermal data obtained by operating the simulator as a conventional dynamometer are in agreement with the contractor's previously reported data. The regeneration test results indicate that a reduction in energy requirements for urban driving cycles is attainable with regenerative braking. Test results and data in this report serve as a data base for further development of ac motor controllers and propulsion systems for electric vehicles. The controller uses state-of-the-art silicon controlled rectifier (SCR) power semiconductors and microprocessor-based logic and control circuitry. The controller was developed by Gould Laboratories under a Lewis contract for the Department of Energy's Electric and Hybrid Vehicle program.

  8. Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates.

    Science.gov (United States)

    Fisichella, Gabriele; Di Franco, Salvatore; Fiorenza, Patrick; Lo Nigro, Raffaella; Roccaforte, Fabrizio; Tudisco, Cristina; Condorelli, Guido G; Piluso, Nicolò; Spartà, Noemi; Lo Verso, Stella; Accardi, Corrado; Tringali, Cristina; Ravesi, Sebastiano; Giannazzo, Filippo

    2013-01-01

    Chemical vapour deposition (CVD) on catalytic metals is one of main approaches for high-quality graphene growth over large areas. However, a subsequent transfer step to an insulating substrate is required in order to use the graphene for electronic applications. This step can severely affect both the structural integrity and the electronic properties of the graphene membrane. In this paper, we investigated the morphological and electrical properties of CVD graphene transferred onto SiO2 and on a polymeric substrate (poly(ethylene-2,6-naphthalene dicarboxylate), briefly PEN), suitable for microelectronics and flexible electronics applications, respectively. The electrical properties (sheet resistance, mobility, carrier density) of the transferred graphene as well as the specific contact resistance of metal contacts onto graphene were investigated by using properly designed test patterns. While a sheet resistance R sh ≈ 1.7 kΩ/sq and a specific contact resistance ρc ≈ 15 kΩ·μm have been measured for graphene transferred onto SiO2, about 2.3× higher R sh and about 8× higher ρc values were obtained for graphene on PEN. High-resolution current mapping by torsion resonant conductive atomic force microscopy (TRCAFM) provided an insight into the nanoscale mechanisms responsible for the very high ρc in the case of graphene on PEN, showing a ca. 10× smaller "effective" area for current injection than in the case of graphene on SiO2. PMID:23616943

  9. Micro- and nanoscale electrical characterization of large-area graphene transferred to functional substrates

    Directory of Open Access Journals (Sweden)

    Gabriele Fisichella

    2013-04-01

    Full Text Available Chemical vapour deposition (CVD on catalytic metals is one of main approaches for high-quality graphene growth over large areas. However, a subsequent transfer step to an insulating substrate is required in order to use the graphene for electronic applications. This step can severely affect both the structural integrity and the electronic properties of the graphene membrane. In this paper, we investigated the morphological and electrical properties of CVD graphene transferred onto SiO2 and on a polymeric substrate (poly(ethylene-2,6-naphthalene dicarboxylate, briefly PEN, suitable for microelectronics and flexible electronics applications, respectively. The electrical properties (sheet resistance, mobility, carrier density of the transferred graphene as well as the specific contact resistance of metal contacts onto graphene were investigated by using properly designed test patterns. While a sheet resistance Rsh ≈ 1.7 kΩ/sq and a specific contact resistance ρc ≈ 15 kΩ·μm have been measured for graphene transferred onto SiO2, about 2.3× higher Rsh and about 8× higher ρc values were obtained for graphene on PEN. High-resolution current mapping by torsion resonant conductive atomic force microscopy (TRCAFM provided an insight into the nanoscale mechanisms responsible for the very high ρc in the case of graphene on PEN, showing a ca. 10× smaller “effective” area for current injection than in the case of graphene on SiO2.

  10. Therapeutic effects of functional electrical stimulation on gait, motor recovery, and motor cortex in stroke survivors

    Directory of Open Access Journals (Sweden)

    C.V. Shendkar, MTech

    2015-06-01

    Conclusion: FES combined with physiotherapy induced better outcomes in the swing phase of the gait cycle, activation of the affected ankle dorsiflexor muscles and cortical function when compared with conventional physiotherapy alone.

  11. Functional electrical stimulation based on a pelvis support robot for gait rehabilitation of hemiplegic patients after stroke.

    Science.gov (United States)

    Ye, Jing; Nakashima, Yasutaka; Zhang, Bo; Kobayashi, Yo; Fujie, Masakatsu G

    2014-01-01

    More and more stroke survivors are suffering from physical motor impairments. Current therapeutic interventions have various limits to the efficient recovery of normal motor function of the lower limbs. Therefore, we propose a novel gait rehabilitation system for hemiplegic patients after stroke. It integrates functional electrical stimulation (FES) with a pelvis-supporting robotic system. A corresponding relationship between the gait phase and the active lateral movement of the pelvis is first constructed from experiments on simulated hemiplegic patients. By estimating the gait phase from the lateral motion of the pelvis based on this relationship, the timing of FES sent to the muscles of the lower limbs can be automatically determined during a gait cycle. After experiments on simulated hemiplegic stroke survivors with the FES control algorithm, the proposed algorithm and the gait rehabilitation system are verified to be feasible and promising.

  12. Photovoltaic Power System with MPPT Functionality for a Small-Size Electric Vehicle

    Directory of Open Access Journals (Sweden)

    Jianming Xu

    2014-01-01

    Full Text Available Electric vehicles are recognized as the best replacement of petrol vehicles in the future. However, there are several problems hampering their development, such as the short life span of batteries, poor performance of start-up, and a short driving range. In order to resolve these problems, a hybrid power system based on photovoltaic (PV cells, supercapacitors, and batteries is proposed. This paper focuses on PV cells using a maximum power point track (MPPT system based on a BUCK chopper circuit. Moreover, a novel MPPT algorithm named sectional variable step climbing (SVSC algorithm was proposed. To validate the proposed system, two main experiments have been done. The first experiment showed that the MPP of PV cells was tracked perfectly by use of this photovoltaic power system. The second one showed that the efficiency of SVSC was higher than two existing MPPT methods, the climbing algorithm and the open-circuit voltage (OCV algorithm.

  13. Investigations of electrical and optical properties of functional TCO thin films

    Directory of Open Access Journals (Sweden)

    Domaradzki Jarosław

    2015-06-01

    Full Text Available Transparent conducting oxide (TCO films of indium-tin-oxide were evaporated on the surface of silicon wafers after phosphorous diffusion and on the reference glass substrates. The influence of deposition process parameters (electron beam current, oxygen flow and the substrate temperature on optical and electrical properties of evaporated thin films were investigated by means of resistivity measurements and optical spectrophotometry. The performance of prepared thin films was judged by calculated figure of merit and the best result was obtained for the sample deposited on the substrate heated to the 100 °C and then removed from the deposition chamber and annealed in an air for 5 minutes at 400 °C. Refractive index and extinction coefficient were evaluated based on measured transmission spectra and used for designing of antireflection coating for solar cell. The obtained results showed that prepared TCO thin films are promising as a part of counter electrode in crystalline silicon solar cell construction.

  14. Quality assurance and functionality tests on electrical components during the ATLAS IBL production

    International Nuclear Information System (INIS)

    During the shutdown of 2013–2014, for the enhancement of the current ATLAS Pixel Detector, a fourth layer (Insertable B Layer, IBL) is being built and will be installed between the innermost layer and a new beam pipe. A new generation of readout chip has been developed, and two different sensor designs, a rather conventional planar and a 3D design, have been bump bonded to the Front Ends. Additionally, new staves and module flex circuits have been developed. A production QA test bench was therefore established to test all production staves before integration with the new beam pipe. Quality assurance measurements under cleanroom conditions, including temperature and humidity control, are being performed on the individual components during the various production steps of the IBL; namely, connectivity tests, electrical tests and signal probing on individual parts and assembled subsystems. This paper discusses the pre-assembly QC procedures, the capabilities of the stave qualification setup, and recent results from stave testing

  15. Quality assurance and functionality tests on electrical components during the ATLAS IBL production

    Science.gov (United States)

    Bassalat, A.

    2014-01-01

    During the shutdown of 2013-2014, for the enhancement of the current ATLAS Pixel Detector, a fourth layer (Insertable B Layer, IBL) is being built and will be installed between the innermost layer and a new beam pipe. A new generation of readout chip has been developed, and two different sensor designs, a rather conventional planar and a 3D design, have been bump bonded to the Front Ends. Additionally, new staves and module flex circuits have been developed. A production QA test bench was therefore established to test all production staves before integration with the new beam pipe. Quality assurance measurements under cleanroom conditions, including temperature and humidity control, are being performed on the individual components during the various production steps of the IBL; namely, connectivity tests, electrical tests and signal probing on individual parts and assembled subsystems. This paper discusses the pre-assembly QC procedures, the capabilities of the stave qualification setup, and recent results from stave testing.

  16. Quality Assurance and Functionality Tests on Electrical Components during the ATLAS IBL Production

    CERN Document Server

    Bassalat, A; The ATLAS collaboration

    2014-01-01

    During the shutdown of 2013-2014, for the enhancement of the current ATLAS Pixel Detector, a fourth layer (Insertable B Layer, IBL) is being built and will be installed between the innermost layer and a new beam pipe. A new generation of readout chip has been developed, and two different sensor designs, a rather conventional planar and a 3D design, have been bump bonded to the Front Ends. Additionally, new staves and module flex circuits have been developed. A production QA test bench was therefore established to test all production staves before integration with the new beam pipe. Quality assurance measurements under cleanroom conditions, including temperature and humidity control, are being performed on the individual components during the various production steps of the IBL; namely, connectivity tests, electrical tests and signal probing on individual parts and assembled subsystems. This paper discusses the pre-assembly QC procedures, the capabilities of the stave qualification setup, and recent results fr...

  17. Tooth reorientation affects tooth function during prey processing and tooth ontogeny in the lesser electric ray, Narcine brasiliensis.

    Science.gov (United States)

    Dean, Mason N; Ramsay, Jason B; Schaefer, Justin T

    2008-01-01

    The dental anatomy of elasmobranch fishes (sharks, rays and relatives) creates a functional system that is more dynamic than that of mammalian dentition. Continuous dental replacement (where new teeth are moved rostrally to replace older ones) and indirect fibrous attachment of the dentition to the jaw allow teeth to reorient relative to the jaw over both long- and short-term scales, respectively. In this study, we examine the processing behavior and dental anatomy of the lesser electric ray Narcine brasiliensis (Olfers, 1831) to illustrate that the freedom of movement of elasmobranch dentition allows a functional flexibility that can be important for complex prey processing behaviors. From static manipulations of dissected jaws and observations of feeding events in live animals, we show that the teeth rotate during jaw protrusion, resulting in a secondary grasping mechanism that likely serves to hold prey while the buccal cavity is flushed free of sediment. The function of teeth is not always readily apparent from morphology; in addition to short-term reorientation, the long-term dental reorientation during replacement allows a given tooth to serve multiple functions during tooth ontogeny. Unlike teeth inside the mouth, the cusps of external teeth (on the portion of the tooth pad that extends past the occlusal plane) lay flat, such that the labial faces act as a functional battering surface, protecting the jaws during prey excavation.

  18. Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

    International Nuclear Information System (INIS)

    Contact materials used for electrical breakers are often made with silver alloys. Mechanical and thermodynamical properties as well as electron emission of such complicated alloys present a lack of reliable and accurate experimental data. This paper deals mainly with electron work function (EWF) measurements about silver–metal (Ag–Me) electrical contacts (Ag–Ni (60/40) and Ag–W (50/50)), before and after surface heat treatments at 513 K–873 K, under UHV conditions (residual gas pressure of 1.4 × 10−7 mbar). The electron work function (EWF) of silver alloyed contacts was measured photoelectrically, using both Fowler's method of isothermal curves and linearized Fowler plots. An interesting fact brought to light by this investigation is that after vacuum heat treatments, the diffusion and/or evaporation phenomena, affecting the atomic composition of the alloy surface, somehow confine the EWF of the silver–nickel alloy, Φ(Ag–Ni), determined at room temperature in interval]Φ(Ag), Φ(Ni) [=] 4.26 eV, 4.51 eV[. Surface analysis of two specimens before and after heating showed a significant increase of tungsten atomic proportion on the contact surface for Ag–W contacts after VH treatments. A multilayer model, taking into account the strong intergranular and volume segregation gives a good interpretation of the obtained results.

  19. Effects of vacuum heat treatment on the photoelectric work function and surface morphology of multilayered silver–metal electrical contacts

    Energy Technology Data Exchange (ETDEWEB)

    Akbi, Mohamed, E-mail: akbi_mohamed@umbb.dz [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France); Department of Physics, Faculty of Sciences, University of Boumerdes (UMBB), Independence Avenue, 35000 Boumerdes (Algeria); Bouchou, Aïssa [Faculty of Physics, University of Algiers (USTHB), B.P. 32, El-Alia, Bab-Ezzouar, 16111 Algiers (Algeria); Zouache, Noureddine [Laboratoire “Arc Electrique et Plasmas Thermiques”, CNRS, UPRES-A 6069, 24, Avenue des Landais, F-63177 Aubière Cedex (France)

    2014-06-01

    Contact materials used for electrical breakers are often made with silver alloys. Mechanical and thermodynamical properties as well as electron emission of such complicated alloys present a lack of reliable and accurate experimental data. This paper deals mainly with electron work function (EWF) measurements about silver–metal (Ag–Me) electrical contacts (Ag–Ni (60/40) and Ag–W (50/50)), before and after surface heat treatments at 513 K–873 K, under UHV conditions (residual gas pressure of 1.4 × 10{sup −7} mbar). The electron work function (EWF) of silver alloyed contacts was measured photoelectrically, using both Fowler's method of isothermal curves and linearized Fowler plots. An interesting fact brought to light by this investigation is that after vacuum heat treatments, the diffusion and/or evaporation phenomena, affecting the atomic composition of the alloy surface, somehow confine the EWF of the silver–nickel alloy, Φ(Ag–Ni), determined at room temperature in interval]Φ(Ag), Φ(Ni) [=] 4.26 eV, 4.51 eV[. Surface analysis of two specimens before and after heating showed a significant increase of tungsten atomic proportion on the contact surface for Ag–W contacts after VH treatments. A multilayer model, taking into account the strong intergranular and volume segregation gives a good interpretation of the obtained results.

  20. Determination of the functional state of the fruits by parameters of the electric impedance

    Directory of Open Access Journals (Sweden)

    E. V. Guseva

    2014-04-01

    Full Text Available Introduction. To assess the freshness of various products are often used measuring impedance module. But due to the structure of plant foods diagnostic value should have exactly a complex component of impedance. Article tasked with developing criteria for assessing the functional state of the products subject to a comprehensive component of the impedance. Research methodology. To determine the functional status of the fruit were measured module and phase of impedance at the three frequencies of 20, 100 and 500 kHz. Criteria for recognition of functional status deter-mined by the dynamics of changes in the parameters of the complex impedance due to destructive processes caused by dehydration and putrefaction processes. Data processing and analysis. On the basis of experimental data obtained at three frequencies modeled frequency and phase response and their changes during losing of freshness and appear-ance of destructive processes. Discussion and conclusions. In fresh and stale fruit modulus and phase of the impedance at low and high frequencies have characteristic differences. But this is especially evident on the phase–frequency characteristic, which can be seen that the value of the phase with the loss of freshness at low frequency decreases and increases at high more than twice during one week. Therefore, to assess the functional state of fresh and stale products we suggest use phase portraits of phase response.

  1. Robotics combined with electrical stimulation: hybrid support of arm and hand for functional training after stroke

    NARCIS (Netherlands)

    Westerveld, A.J.

    2014-01-01

    Reach, grasp and release is part of many functional movements. Graying of society leads to more stroke victims and fewer health care professionals. Technology might be a solution to support certain rehabilitation therapies in future health care. Robotic systems have been developed for support of arm

  2. A comparative density functional study on electrical properties of layered penta-graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zhi Gen, E-mail: yuzg@ihpc.a-star.edu.sg; Zhang, Yong-Wei, E-mail: zhangyw@ihpc.a-star.edu.sg [Institute of High Performance Computing, Singapore 138632 (Singapore)

    2015-10-28

    We present a comparative study of the influence of the number of layers, the biaxial strain in the range of −3% to 3%, and the stacking misalignments on the electronic properties of a new 2D carbon allotrope, penta-graphene (PG), based on hybrid-functional method within the density functional theory (DFT). In comparison with local exchange-correlation approximation in the DFT, the hybrid-functional provides an accurate description on the degree of p{sub z} orbitals localization and bandgap. Importantly, the predicted bandgap of few-layer PG has a weak layer dependence. The bandgap of monolayer PG is 3.27 eV, approximately equal to those of GaN and ZnO; and the bandgap of few-layer PG decreases slowly with the number of layers (N) and converge to 2.57 eV when N ≥ 4. Our calculations using HSE06 functional on few-layer PG reveal that bandgap engineering by stacking misalignment can further tune the bandgap down to 1.37 eV. Importantly, there is no direct-to-indirect bandgap transition in PG by varying strain, layer number, and stacking misalignment. Owing to its tunable, robustly direct, and wide bandgap characteristics, few-layer PG is promising for optoelectronic and photovoltaic applications.

  3. A comparative density functional study on electrical properties of layered penta-graphene

    Science.gov (United States)

    Yu, Zhi Gen; Zhang, Yong-Wei

    2015-10-01

    We present a comparative study of the influence of the number of layers, the biaxial strain in the range of -3% to 3%, and the stacking misalignments on the electronic properties of a new 2D carbon allotrope, penta-graphene (PG), based on hybrid-functional method within the density functional theory (DFT). In comparison with local exchange-correlation approximation in the DFT, the hybrid-functional provides an accurate description on the degree of pz orbitals localization and bandgap. Importantly, the predicted bandgap of few-layer PG has a weak layer dependence. The bandgap of monolayer PG is 3.27 eV, approximately equal to those of GaN and ZnO; and the bandgap of few-layer PG decreases slowly with the number of layers (N) and converge to 2.57 eV when N ≥ 4. Our calculations using HSE06 functional on few-layer PG reveal that bandgap engineering by stacking misalignment can further tune the bandgap down to 1.37 eV. Importantly, there is no direct-to-indirect bandgap transition in PG by varying strain, layer number, and stacking misalignment. Owing to its tunable, robustly direct, and wide bandgap characteristics, few-layer PG is promising for optoelectronic and photovoltaic applications.

  4. Electrical behavior of amide functionalized graphene oxide and graphene oxide films annealed at different temperatures

    International Nuclear Information System (INIS)

    Films of graphene oxide (GO) and amide functionalized graphene oxides (AGOs) were deposited on SiO2/Si(100) by spin coating and were thermally annealed at different temperatures. Sheet resistance of GO and AGOs films was measured using four probe resistivity method. GO an insulator at room temperature, exhibits decrease in sheet resistance with increase in annealing temperature. However, AGOs' low sheet resistance (250.43 Ω) at room temperature further decreases to 39.26 Ω after annealing at 800 °C. It was observed that the sheet resistance of GO was more than AGOs up to 700 °C, but effect was reversed after annealing at higher temperature. At higher annealing temperatures the oxygen functionality reduces in GO and sheet resistance decreases. Sheet resistance was found to be annealing time dependent. Longer duration of annealing at a particular temperature results in decrease of sheet resistance. - Highlights: • Amide functionalized graphene oxides (AGOs) were synthesized at room temperature (RT). • AGO films have low sheet resistance at RT as compared to graphene oxide (GO). • Fast decrease in the sheet resistance of GO with annealing as compared to AGOs • AGOs were found to be highly dispersible in polar solvents

  5. The need for seasonal correction functions when calculating the annual electricity use of appliances based on shorter period measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bennich, Peter (Testlab, The Swedish Energy Agency, Eskilstuna (Sweden)); Oefverholm, Egil; Bjoern, Torgny (The Swedish Energy Agency, Eskilstuna (Sweden)); Norstedt, Inger (The Swedish Consumer Agency, Stockholm (Sweden))

    2011-07-01

    Along with the increasing number of smart electricity meters in the homes - both meters installed by the utilities and simpler ones installed by the household owners themselves - the interest in reliable methods for scaling up data measured during a limited time of the year to annual values, will most likely increase. For example, by measuring some specific loads for some time in a home, an inhabitant may assess possible annual savings when replacing old appliances with new ones. However, a straight forward scaling up calculation to annual values is not always appropriate. An obvious example is lighting, which displays a clear seasonal effect due to the difference in daylight: annual values based on measured summer data will strongly underestimate the annual consumption whereas winter data will lead to an overestimate. Another example going in the opposite direction is cold appliances, where the increase in ambient temperature during the summer increases the electricity consumption. This paper discusses an analysis of a set of appliances which nearly all display different seasonal effects. Apart from lighting and cold appliances, also washing machines, dish washers, TVs and PCs are analysed. Factors influencing the seasonality are discussed; either it is due to behaviour and/or technical parameters as well. Our analysis is based on 10 min measurements of appliances in 400 randomly selected households in Sweden. 40 households were measured during a full year and provided data for establishing seasonal correction functions. (See Appendix 1 for more details on the methodology.)

  6. Characterization of terrestrial solar cells for space applications: Electrical characteristics of thin Westinghouse dendritic web cells as a function of solar intensity, temperature, and incidence angle

    Science.gov (United States)

    Stella, P. M.; Anspaugh, B. E.

    1985-01-01

    Electrical characteristics of thin (100- and 140-micron) Westinghouse dendritic-web N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. Performance is also shown as a function of solar illlumination angle of incidence for AMO.

  7. Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report.

    Science.gov (United States)

    Reese, David; Shivapour, Ezzatolah T; Wahls, Terry L; Dudley-Javoroski, Shauna D; Shields, Richard

    2009-01-01

    Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the first 2 months of neuromuscular electrical stimulation, the therapist observed modest gait improvements. Following the addition of nutritional interventions, more rapids gains in strength and endurance, including muscle groups not receiving neuromuscular electrical stimulation were observed by both the therapist and the patient. After 8 months of neuromuscular electrical stimulation (6 months of nutritional intervention) the patient's function had improved sufficiently that she no longer used a scooter or cane and rode her bicycle routinely 8 miles, including hills. PMID:19918474

  8. Brain-computer interface driven functional electrical stimulation system for overground walking in spinal cord injury participant.

    Science.gov (United States)

    King, Christine E; Wang, Po T; McCrimmon, Colin M; Chou, Cathy C Y; Do, An H; Nenadic, Zoran

    2014-01-01

    The current treatment for ambulation after spinal cord injury (SCI) is to substitute the lost behavior with a wheelchair; however, this can result in many co-morbidities. Thus, novel solutions for the restoration of walking, such as brain-computer interfaces (BCI) and functional electrical stimulation (FES) devices, have been sought. This study reports on the first electroencephalogram (EEG) based BCI-FES system for overground walking, and its performance assessment in an individual with paraplegia due to SCI. The results revealed that the participant was able to purposefully operate the system continuously in real time. If tested in a larger population of SCI individuals, this system may pave the way for the restoration of overground walking after SCI.

  9. Upper-limb stroke rehabilitation using electrode-array based functional electrical stimulation with sensing and control innovations.

    Science.gov (United States)

    Kutlu, M; Freeman, C T; Hallewell, E; Hughes, A-M; Laila, D S

    2016-04-01

    Functional electrical stimulation (FES) has shown effectiveness in restoring upper-limb movement post-stroke when applied to assist participants' voluntary intention during repeated, motivating tasks. Recent clinical trials have used advanced controllers that precisely adjust FES to assist functional reach and grasp tasks with FES applied to three muscle groups, showing significant reduction in impairment. The system reported in this paper advances the state-of-the-art by: (1) integrating an FES electrode array on the forearm to assist complex hand and wrist gestures; (2) utilising non-contact depth cameras to accurately record the arm, hand and wrist position in 3D; and (3) employing an interactive touch table to present motivating virtual reality (VR) tasks. The system also uses iterative learning control (ILC), a model-based control strategy which adjusts the applied FES based on the tracking error recorded on previous task attempts. Feasibility of the system has been evaluated in experimental trials with 2 unimpaired participants and clinical trials with 4 hemiparetic, chronic stroke participants. The stroke participants attended 17, 1 hour training sessions in which they performed functional tasks, such as button pressing using the touch table and closing a drawer. Stroke participant results show that the joint angle error norm reduced by an average of 50.3% over 6 attempts at each task when assisted by FES.

  10. The Development of control system via Brain Computer Interface (BCI - Functional Electrical Stimulation (FES for paraplegic subject

    Directory of Open Access Journals (Sweden)

    K. A. A. Rahman

    2012-12-01

    Full Text Available Brain is known to be one of the powerful systems in human body because of its ability to give command and communicate throughout the body. The spinal cord is the pathway for impulses from the brain to the body as well as from the body to the brain. However, the bounty of this pathway could be lost due to spinal cord injury (SCI and that results in a loss of function especially mobility. A combination of Brain Computer Interface (BCI and Functional Electrical Stimulation (FES is among one of the technique to regain the mobility function of human body which will be the focused area of this research. In this study, Electroencephalography (EEG system will be used to capture the brain signal which will then drive the FES. A paraplegic subject will be involved in this study. The subject will be required to move the knee joint with involvement few muscle contraction. Overall, in this paper the combination of BCI-FES methods for development of rehabilitation system will be proposed. From this preliminary study, it can be summarized that the combination between BCI and FES potentially would provide a better rehabilitation system for SCI patient in comparison to the conventional FES system.

  11. Design and application of electric oil pump in automatic transmission for efficiency improvement and start–stop function

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-fang; DONG Peng; LIU Yang; XU Xiang-yang

    2016-01-01

    For the purpose of improving efficiency and realizing start–stop function, an electric oil pump (EOP) is integrated into an 8-speed automatic transmission (AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump (MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.

  12. Upper-limb stroke rehabilitation using electrode-array based functional electrical stimulation with sensing and control innovations.

    Science.gov (United States)

    Kutlu, M; Freeman, C T; Hallewell, E; Hughes, A-M; Laila, D S

    2016-04-01

    Functional electrical stimulation (FES) has shown effectiveness in restoring upper-limb movement post-stroke when applied to assist participants' voluntary intention during repeated, motivating tasks. Recent clinical trials have used advanced controllers that precisely adjust FES to assist functional reach and grasp tasks with FES applied to three muscle groups, showing significant reduction in impairment. The system reported in this paper advances the state-of-the-art by: (1) integrating an FES electrode array on the forearm to assist complex hand and wrist gestures; (2) utilising non-contact depth cameras to accurately record the arm, hand and wrist position in 3D; and (3) employing an interactive touch table to present motivating virtual reality (VR) tasks. The system also uses iterative learning control (ILC), a model-based control strategy which adjusts the applied FES based on the tracking error recorded on previous task attempts. Feasibility of the system has been evaluated in experimental trials with 2 unimpaired participants and clinical trials with 4 hemiparetic, chronic stroke participants. The stroke participants attended 17, 1 hour training sessions in which they performed functional tasks, such as button pressing using the touch table and closing a drawer. Stroke participant results show that the joint angle error norm reduced by an average of 50.3% over 6 attempts at each task when assisted by FES. PMID:26947097

  13. Using Functional Electrical Stimulation Mediated by Iterative Learning Control and Robotics to Improve Arm Movement for People With Multiple Sclerosis.

    Science.gov (United States)

    Sampson, Patrica; Freeman, Chris; Coote, Susan; Demain, Sara; Feys, Peter; Meadmore, Katie; Hughes, Ann-Marie

    2016-02-01

    Few interventions address multiple sclerosis (MS) arm dysfunction but robotics and functional electrical stimulation (FES) appear promising. This paper investigates the feasibility of combining FES with passive robotic support during virtual reality (VR) training tasks to improve upper limb function in people with multiple sclerosis (pwMS). The system assists patients in following a specified trajectory path, employing an advanced model-based paradigm termed iterative learning control (ILC) to adjust the FES to improve accuracy and maximise voluntary effort. Reaching tasks were repeated six times with ILC learning the optimum control action from previous attempts. A convenience sample of five pwMS was recruited from local MS societies, and the intervention comprised 18 one-hour training sessions over 10 weeks. The accuracy of tracking performance without FES and the amount of FES delivered during training were analyzed using regression analysis. Clinical functioning of the arm was documented before and after treatment with standard tests. Statistically significant results following training included: improved accuracy of tracking performance both when assisted and unassisted by FES; reduction in maximum amount of FES needed to assist tracking; and less impairment in the proximal arm that was trained. The system was well tolerated by all participants with no increase in muscle fatigue reported. This study confirms the feasibility of FES combined with passive robot assistance as a potentially effective intervention to improve arm movement and control in pwMS and provides the basis for a follow-up study.

  14. Using Functional Electrical Stimulation Mediated by Iterative Learning Control and Robotics to Improve Arm Movement for People With Multiple Sclerosis.

    Science.gov (United States)

    Sampson, Patrica; Freeman, Chris; Coote, Susan; Demain, Sara; Feys, Peter; Meadmore, Katie; Hughes, Ann-Marie

    2016-02-01

    Few interventions address multiple sclerosis (MS) arm dysfunction but robotics and functional electrical stimulation (FES) appear promising. This paper investigates the feasibility of combining FES with passive robotic support during virtual reality (VR) training tasks to improve upper limb function in people with multiple sclerosis (pwMS). The system assists patients in following a specified trajectory path, employing an advanced model-based paradigm termed iterative learning control (ILC) to adjust the FES to improve accuracy and maximise voluntary effort. Reaching tasks were repeated six times with ILC learning the optimum control action from previous attempts. A convenience sample of five pwMS was recruited from local MS societies, and the intervention comprised 18 one-hour training sessions over 10 weeks. The accuracy of tracking performance without FES and the amount of FES delivered during training were analyzed using regression analysis. Clinical functioning of the arm was documented before and after treatment with standard tests. Statistically significant results following training included: improved accuracy of tracking performance both when assisted and unassisted by FES; reduction in maximum amount of FES needed to assist tracking; and less impairment in the proximal arm that was trained. The system was well tolerated by all participants with no increase in muscle fatigue reported. This study confirms the feasibility of FES combined with passive robot assistance as a potentially effective intervention to improve arm movement and control in pwMS and provides the basis for a follow-up study. PMID:25823038

  15. Single session of brief electrical stimulation immediately following crush injury enhances functional recovery of rat facial nerve

    Directory of Open Access Journals (Sweden)

    Eileen M. Foecking, PhD

    2012-04-01

    Full Text Available Peripheral nerve injuries lead to a variety of pathological conditions, including paresis or paralysis when the injury involves motor axons. We have been studying ways to enhance the regeneration of peripheral nerves using daily electrical stimulation (ES following a facial nerve crush injury. In our previous studies, ES was not initiated until 24 h after injury. The current experiment tested whether ES administered immediately following the crush injury would further decrease the time for complete recovery from facial paralysis. Rats received a unilateral facial nerve crush injury and an electrode was positioned on the nerve proximal to the crush site. Animals received daily 30 min sessions of ES for 1 d (day of injury only, 2 d, 4 d, 7 d, or daily until complete functional recovery. Untreated animals received no ES. Animals were observed daily for the return of facial function. Our findings demonstrated that one session of ES was as effective as daily stimulation at enhancing the recovery of most functional parameters. Therefore, the use of a single 30 min session of ES as a possible treatment strategy should be studied in human patients with paralysis as a result of acute nerve injuries.

  16. A new enhanced bat-inspired algorithm for finding linear supply function equilibrium of GENCOs in the competitive electricity market

    International Nuclear Information System (INIS)

    Highlights: • Present optimal bidding strategies of Generating Companies (GENCOs) in a network-constrained electricity market. • Present new enhanced bat-inspired algorithm. • Consider the bi level optimization problem. • Present a linear supply function model. - Abstract: This paper proposes a new enhanced bat-inspired algorithm to find out linear supply function equilibrium of Generating Companies (GENCOs) in a network-constrained electricity market where they have incomplete information about other rivals. The model enables a GENCO to link its bidding price with the bidding quantity of its product. In this regard, the social welfare maximization is applied to clearing the market and nodal pricing mechanism is utilized to calculate the GENCO’s profit. It is formulated as a bi level optimization problem, where the higher level problem maximizes GENCO’s payoff and the lower level problem solves the independent system operator’s market clearing problem based on the maximization of social welfare. Due to non-convexity nature of the proposed bi level optimization problem, the mathematical-based optimization approach is incapable to solve the problem and obtain the nearly global optima. In order to overcome the obstacle of the conventional approaches, this study suggests a new meta-heuristic Bat-inspired Algorithm (BA) to achieve the nearly global solution of the bi level optimization problem. In addition a novel self-adaptive learning mechanism is utilized on the original BA to improve the population diversity and global searching capability. Numerical examples are applied to three test systems in order to evaluate the performances of the presented framework

  17. Comparison of muscle functional electrical stimulation to conventional bicycle exercise on endothelium and functional status indices in patients with heart failure.

    Science.gov (United States)

    Deftereos, Spyridon; Giannopoulos, Georgios; Raisakis, Konstantinos; Kossyvakis, Charalampos; Kaoukis, Andreas; Driva, Metaxia; Pappas, Loukas; Panagopoulou, Vasiliki; Ntzouvara, Olga; Karavidas, Apostolos; Pyrgakis, Vlasios; Rentoukas, Ilias; Aggeli, Constadina; Stefanadis, Christodoulos

    2010-12-01

    The aim of this prospective, open-label, cohort study was to compare the effect of muscle functional electrical stimulation (FES) on endothelial function to that of conventional bicycle training. Eligible patients were those with New York Heart Association class II or III heart failure symptoms and ejection fractions ≤ 0.35. Two physical conditioning programs were delivered: FES of the muscles of the lower limbs and bicycle training, each lasting for 6 weeks, with a 6-week washout period between them. Brachial artery flow-mediated dilation (FMD) and other parameters were assessed before and after FES and the bicycle training program. FES resulted in a significant improvement in FMD, which increased from 5.9 ± 0.5% to 7.7 ± 0.5% (95% confidence interval for the difference 1.5% to 2.3%, p Bicycle training also resulted in a substantial improvement of endothelial function. FMD increased from 6.2 ± 0.4% to 9.2 ± 0.4% (95% confidence interval for the difference 2.5% to 3.5%, p bicycle exercise (95% confidence interval for the difference between the relative changes 1.2% to 30.5%, p = 0.034). This resulted in attaining a significantly higher FMD value after bicycle training compared to FES (9.2 ± 0.4% vs 7.7 ± 0.5%, p < 0.001). In conclusion, the effect of muscle FES in patients with heart failure on endothelial function, although not equivalent to that of conventional exercise, is substantial. Muscle FES protocols may prove very useful in the treatment of patients with heart failure who cannot or will not adhere to conventional exercise programs.

  18. Comparison of muscle functional electrical stimulation to conventional bicycle exercise on endothelium and functional status indices in patients with heart failure.

    Science.gov (United States)

    Deftereos, Spyridon; Giannopoulos, Georgios; Raisakis, Konstantinos; Kossyvakis, Charalampos; Kaoukis, Andreas; Driva, Metaxia; Pappas, Loukas; Panagopoulou, Vasiliki; Ntzouvara, Olga; Karavidas, Apostolos; Pyrgakis, Vlasios; Rentoukas, Ilias; Aggeli, Constadina; Stefanadis, Christodoulos

    2010-12-01

    The aim of this prospective, open-label, cohort study was to compare the effect of muscle functional electrical stimulation (FES) on endothelial function to that of conventional bicycle training. Eligible patients were those with New York Heart Association class II or III heart failure symptoms and ejection fractions ≤ 0.35. Two physical conditioning programs were delivered: FES of the muscles of the lower limbs and bicycle training, each lasting for 6 weeks, with a 6-week washout period between them. Brachial artery flow-mediated dilation (FMD) and other parameters were assessed before and after FES and the bicycle training program. FES resulted in a significant improvement in FMD, which increased from 5.9 ± 0.5% to 7.7 ± 0.5% (95% confidence interval for the difference 1.5% to 2.3%, p Bicycle training also resulted in a substantial improvement of endothelial function. FMD increased from 6.2 ± 0.4% to 9.2 ± 0.4% (95% confidence interval for the difference 2.5% to 3.5%, p bicycle exercise (95% confidence interval for the difference between the relative changes 1.2% to 30.5%, p = 0.034). This resulted in attaining a significantly higher FMD value after bicycle training compared to FES (9.2 ± 0.4% vs 7.7 ± 0.5%, p < 0.001). In conclusion, the effect of muscle FES in patients with heart failure on endothelial function, although not equivalent to that of conventional exercise, is substantial. Muscle FES protocols may prove very useful in the treatment of patients with heart failure who cannot or will not adhere to conventional exercise programs. PMID:21094364

  19. A modular function architecture for adaptive and predictive energy management in hybrid electric vehicles; Eine modulare Funktionsarchitektur fuer adaptives und vorausschauendes Energiemanagement in Hybridfahrzeugen

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, Andreas

    2009-10-27

    Due to the relatively low energy density of electrical energy storage devices, the control strategy of hybrid electric vehicles has to fulfil a variety of requirements in order to provide both, the availability of hybrid functions, and their efficient execution. Energy consuming functions such as electric drive or electric boost need a high amount of energy stored in the battery. On the other hand for the optimum use of the energy regeneration function a lower state of charge is preferable in order to enable storage of the kinetic energy of the vehicle in all situations, including upon deceleration from high speeds or downhill driving. These diverging requirements yield a conflict of objectives for the charging strategy of hybrid electric vehicles. This work proposes a way to overcome the restrictions on efficiency in hybrid electric vehicles without deteriorating overall driving performance by charging or discharging the traction battery, and by setting the energy management parametres according to the current and forthcoming driving situation. Specific charging and electric drive strategies are presented for various driving situations which are identified by sensors such as navigation systems, cameras or radar. Necessary sensor data fusion methods for driving situation identification are described and a modular function architecture for predictive energy management is derived that is plug-and-play compatible with a broad fleet of vehicles. In order to evaluate its potential, this work also focuses on the simulation of the energy functions and their implementation into an experimental vehicle. This allows measurements under real traffic conditions and a sensivity analysis of the main module interactions within the architecture. (orig.)

  20. Density Functional Theory simulations of water: phase-diagram and electrical conductivity

    Science.gov (United States)

    Mattsson, Thomas R.; Desjarlais, Michael P.

    2006-10-01

    Knowledge of the properties of water is essential for correctly describing the physics of giant planets as well as shock waves in water. By using finite temperature density functional theory (DFT) we have investigated the structure and electronic conductivity of water across three phase transitions (molecular liquid/ ionic liquid/ superionic/ electronic liquid). There is a rapid transition to ionic conduction at 2000 K and 2 g/cm^3 while electronic conduction dominates at temperatures at and above 6000 K. We predict that the fluid bordering the superionic phase is conducting above 4000 K and 100 GPa [1]. Earlier work instead has the superionic phase bordering an insulating fluid, with a transition to metallic fluid not until 7000 K and 250 GPa. The LDRD office at SNL supported this work. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. [1] T.R. Mattsson and M.P. Desjarlais, Phys. Rev. Lett. 97, 017801 (2006).

  1. Measurement of the Electric and Magnetic Elastic Structure Functions of the Deuteron at Large Momentum Transfers

    Energy Technology Data Exchange (ETDEWEB)

    Riad Suleiman

    1999-10-01

    The deuteron elastic structure functions, A(Q{sup 2}) and B(Q{sup 2}), have been extracted from cross section measurements of elastic electron-deuteron scattering in coincidence using the Continuous Electron Beam Accelerator and Hall A Facilities of Jefferson Laboratory. Incident electrons were scattered off a high-power cryogenic deuterium target. Scattered electrons and recoil deuterons were detected in the two High Resolution Spectrometers of Hall A. A(Q{sup 2}) was extracted from forward angle cross section measurements in the squared four-momentum transfer range 0.684 ≤ Q{sup 2} ≤ 5.90 (GeV/c){sup 2}. B(Q{sup 2}) was determined by means of a Rosenbluth separation in the range 0.684 ≤ Q{sup 2} ≤ 1.325 (GeV/c){sup 2}. The data are compared to theoretical models based on the impulse approximation with the inclusion of meson-exchange currents and to predictions of quark dimensional scaling and perturbative quantum chromodynamics. The results are expected to provide insights into the transition from meson-nucleon to quark-gluon descriptions of the nuclear two-body system.

  2. Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain's control circuit

    OpenAIRE

    Volkow, Nora D.; Wang, Gene-Jack; Fowler, Joanna S.; Tomasi, Dardo; Telang, Frank; Baler, Ruben

    2010-01-01

    Based on brain imaging findings, we present a model according to which addiction emerges as an imbalance in the information processing and integration among various brain circuits and functions. The dysfunctions reflect (a) decreased sensitivity of reward circuits, (b) enhanced sensitivity of memory circuits to conditioned expectations to drugs and drug cues, stress reactivity, and (c) negative mood, and a weakened control circuit. Although initial experimentation with a drug of abuse is larg...

  3. Design and Control of a Multi-Functional Energy Recovery Power Accumulator Battery Pack Testing System for Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Bo Long

    2014-03-01

    Full Text Available In this paper, aiming at the energy loss and harmonic problems in the conventional power accumulator battery pack testing system (PABPTS, an improved multi-functional energy recovery PABPTS (ERPABPTS for electric vehicles (EVs was proposed. The improved system has the functions of harmonic detection, suppression, reactive compensation and energy recovery. The ERPABPTS, which contains a bi-directional buck-boost direct current (DC-DC converter and a bi-directional alternating current (AC-DC converter with an inductor-capacitor-inductor (LCL type filter interfacing to the AC-grid, is proposed. System configuration and operation principle of the combined system are discussed first, then, the reactive compensation and harmonic suppression controller under balanced grid-voltage condition are presented. Design of a fourth order band-pass Butterworth filter for current harmonic detection is put forward, and the reactive compensator design procedure considering the non-linear load is also illustrated. The proposed scheme is implemented in a 175-kW prototype in the laboratory. Simulation and experimental results show that the combined configuration can effectively realize energy recovery for high accuracy current test requirement, meanwhile, can effectively achieve reactive compensation and current harmonic suppression.

  4. Study on the Position and Function of Electricity Marketing in Electric Power Enterprise%电力市场营销在电力企业中的定位与作用研究

    Institute of Scientific and Technical Information of China (English)

    许登月

    2012-01-01

    The electricity marketing is the outcome of the electricity marketization reaching a certain stage.The concept of it is defined in this paper.From a microscopic perspective and a macroscopic perspective,the position of it in electric power enterprise is particularly analyzed.Furthermore,the function of it is also discussed.%电力市场营销是电力市场化改革发展到一定阶段的产物。本文对电力市场营销的概念进行了界定;重点从微观和宏观角度探讨了电力市场营销在电力企业中的定位及其所应发挥的作用与职能。

  5. Response of the Shockley surface state on Cu(111) to an external electrical field: A density-functional theory study

    Science.gov (United States)

    Berland, Kristian; Hyldgaard, Per; Einstein, T. L.

    2011-03-01

    We study the response of the Cu(111) Shockley surface state to an external electrical field E by combining a density-functional theory calculation for a finite slab geometry with an analysis of the Kohn-Sham wavefunctions to obtain a well-converged characterization. We find that the surface state displays isotropic dispersion, quadratic until the Fermi wave vector but with a significant quartic contribution beyond. We find that the shift in band minimum and effective mass depend linearly on E. Most change in electrostatic potential profile, and charge transfer occurs outside the outermost copper atoms, and most of the screening is due to bulk electrons. Our analysis is facilitated by a method used to decouple the Kohn-Sham states due to the finite slab geometry, using a rotation in Hilbert space. We discuss applications to tuning the Fermi wavelength and so the many patterns attributed to metallic surface states. Supported by (KB and PH) Swedish Vetenskapsrådet VR 621-2008-4346 and (TLE) NSF CHE 07-50334 & UMD MRSEC DMR 05-20471.

  6. Effect of adjusting pulse durations of functional electrical stimulation cycling on energy expenditure and fatigue after spinal cord injury

    Directory of Open Access Journals (Sweden)

    Ashraf S. Gorgey, MPT, PhD, FACSM

    2015-02-01

    Full Text Available The purpose of the current study was to determine the effects of three different pulse durations (200, 350, and 500 microseconds [P200, P350, and P500, respectively] on oxygen uptake, cycling performance, and energy expenditure (EE percentage of fatigue of the knee extensor muscle group immediately and 48 to 72 h after cycling in persons with spinal cord injury (SCI. A convenience sample of 10 individuals with motor complete SCI participated in a repeated-measures design using a functional electrical stimulation (FES cycle ergometer over a 3 wk period. There was no difference among the three FES protocols on relative oxygen uptake or cycling EE. Delta EE between exercise and rest was 42% greater in both P500 and P350 than in P200 (p = 0.07, whereas recovery oxygen uptake was 23% greater in P350 than in P200 (p = 0.03. There was no difference in the outcomes of the three pulse durations on muscle fatigue. Knee extensor torque significantly decreased immediately after (p < 0.001 and 48 to 72 h after (p < 0.001 FES leg cycling. Lengthening pulse duration did not affect submaximal or relative oxygen uptake or EE, total EE, and time to fatigue. Greater recovery oxygen updake and delta EE were noted in P350 and P500 compared with P200. An acute bout of FES leg cycling resulted in torque reduction that did not fully recover 48 to 72 h after cycling.

  7. Myoelectrically driven functional electrical stimulation may increase motor recovery of upper limb in poststroke subjects: A randomized controlled pilot study

    Directory of Open Access Journals (Sweden)

    Rune Thorsen, PhD, MScee

    2013-08-01

    Full Text Available The objective of this randomized controlled pilot study was to assess the feasibility and effectiveness of myoelectrically controlled functional electrical stimulation (MeCFES for rehabilitation of the upper limb in poststroke subjects. Eleven poststroke hemiparetic subjects with residual proximal control of the arm, but impaired volitional opening of the paretic hand, were enrolled and randomized into a treated and a control group. Subjects received 3 to 5 treatment sessions per week until totaling 25 sessions. In the experimental group, myoelectric activity from wrist and finger extensors was used to control stimulation of the same muscles. Patients treated with MeCFES (n = 5 had a significant (p = 0.04 and clinically important improvement in Action Research Arm Test score (median change 9 points, confirmed by an Individually Prioritized Problem Assessment self-evaluation score. This improvement was maintained at follow-up. The control group did not show a significant improvement (p = 0.13. The reduced sample size of participants, together with confounding factors such as spontaneous recovery, calls for larger studies to draw definite conclusions. However, the large and persistent treatment effect seen in our results indicate that MeCFES could play an important role as a clinical tool for stroke rehabilitation.

  8. Functional magnetic resonance imaging of the rat cerebellum during electrical stimulation of the fore- and hindpaw at 7 T

    Science.gov (United States)

    Peeters, Ronald; Verhoye, Marleen; Vos, Bart; De Schutter, Erik; Van der Linden, Anne-Marie

    1999-05-01

    Blood oxygenation level dependent contrast (BOLD) functional MRI responses at 7T were observed in the cerebellum of alpha- chloralose anesthetized rats in response to innocuous electrical stimulation of a forepaw or hindpaw. The responses were imaged in both coronal and sagittal slices which allowed for a clear delineation and localization of the observed activations. We demonstrate the validity of our fMRI protocol by imaging the responses in somatosensory cortex to the same stimuli and by showing a high level of reproducibility of the cerebellar responses. Widespread bilateral activations were found with mainly a patchy and medio-lateral band organization, more pronounced ipsilaterally. There was no overlap between the cerebellar activations caused by forepaw or hindpaw stimulation. Most remarkable was the overall horizontal organization of these responses: for both stimulation paradigms the patches and bands of activation were roughly positioned in either a cranial or caudal plane running antero-posteriorly through the whole cerebellum. This is the first fMRI study in the cerebellum of the rat. We relate our findings to the known projection patterns found with other techniques and to human fMRI studies. The horizontal organization found wasn't observed before in other studies using other techniques.

  9. Effects of oculo-motor exercise, functional electrical stimulation and proprioceptive neuromuscular stimulation on visual perception of spatial neglect patients.

    Science.gov (United States)

    Park, Si-Eun; Oh, Dae-Sik; Moon, Sang-Hyun

    2016-04-01

    [Purpose] The purpose of this study was to identify the effects of oculo-motor exercise, functional electrical stimulation (FES), and proprioceptive neuromuscular facilitation (PNF) on the visual perception of spatial neglect patients. [Subjects and Methods] The subjects were randomly allocated to 3 groups: an oculo-motor exercise (OME) group, a FES with oculo-motor exercise (FOME) group, and a PNF with oculo-motor exercise (POME) group. The line bisection test (LBT), motor free visual test (MVPT), and Catherine Bergego Scale (CBS) were used to measure visual perception. These were performed 5 times per week for 6 weeks. [Results] The OME group and POME group showed significant improvements according to the LBT and MVPT results, but the FOME group showed no significant improvement. According to the CBS, all 3 groups showed significant improvements. The OME and POME groups showed improvement over the FOME group in the LBT and MVPT. However, there was no significant difference among the three groups according to the CBS. [Conclusion] These results indicate that oculo-motor exercise and PNF with oculo-motor exercise had more positive effects than FES with oculo-motor exercise on the visual perception of spatial neglect patients.

  10. Medical criteria for active physical therapy. Physician guidelines for patient participation in a program of functional electrical rehabilitation.

    Science.gov (United States)

    Phillips, C A

    1987-10-01

    Medical guidelines are presented by which the physician may evaluate a patient for participation in a program of active physical therapy (A.P.T.). A.P.T. system modalities are introduced and defined as: a) isokinetic leg trainer, b) stationary bicycle ergometer, c) outdoor exercise bicycle, and d) Functional Electrical Stimulation (F.E.S.)--Orthosis for ambulation. The physiological responses to these F.E.S. exercise modalities are reviewed. Initial and interim patient evaluations are discussed. The initial patient evaluation includes a history, physical examination, lab tests, and a report summary, all of which culminate in an F.E.S. exercise prescription. The interim patient evaluation is performed for continuation-termination purposes as well as to progress the patient through the various F.E.S. exercise modalities. Specific F.E.S. exercise progression criteria are summarized. The medical criteria are presented with respect to both patient participation in the F.E.S. exercise program and patient monitoring during the exercise itself. Specific medical criteria for patient participation in A.P.T. are organized around eight functional categories: a) level of neurological injury, b) muscular system, c) skeletal system, subdivided into bone criteria and joint criteria, d) cardiovascular system, e) respiratory system, f) urogenital system, g) cutaneous system, and h) psychological system. The medical criteria for patient monitoring during F.E.S. exercise are discussed with respect to: a) cardiovascular monitoring, b) objective patient monitoring, and c) F.E.S. exercise system monitoring. The article concludes with a discussion of informed consent when applied to an emerging treatment modality.

  11. Design of a 32-Channel EEG System for Brain Control Interface Applications

    Directory of Open Access Journals (Sweden)

    Ching-Sung Wang

    2012-01-01

    Full Text Available This study integrates the hardware circuit design and the development support of the software interface to achieve a 32-channel EEG system for BCI applications. Since the EEG signals of human bodies are generally very weak, in addition to preventing noise interference, it also requires avoiding the waveform distortion as well as waveform offset and so on; therefore, the design of a preamplifier with high common-mode rejection ratio and high signal-to-noise ratio is very important. Moreover, the friction between the electrode pads and the skin as well as the design of dual power supply will generate DC bias which affects the measurement signals. For this reason, this study specially designs an improved single-power AC-coupled circuit, which effectively reduces the DC bias and improves the error caused by the effects of part errors. At the same time, the digital way is applied to design the adjustable amplification and filter function, which can design for different EEG frequency bands. For the analog circuit, a frequency band will be taken out through the filtering circuit and then the digital filtering design will be used to adjust the extracted frequency band for the target frequency band, combining with MATLAB to design man-machine interface for displaying brain wave. Finally the measured signals are compared to the traditional 32-channel EEG signals. In addition to meeting the IFCN standards, the system design also conducted measurement verification in the standard EEG isolation room in order to demonstrate the accuracy and reliability of this system design.

  12. Reduced metabolism in brain "control networks" following cocaine-cues exposure in female cocaine abusers.

    Directory of Open Access Journals (Sweden)

    Nora D Volkow

    Full Text Available OBJECTIVE: Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved. METHOD: To test this we compared brain metabolism (using PET and ¹⁸FDG between female (n = 10 and male (n = 16 active cocaine abusers when they watched a neutral video (nature scenes versus a cocaine-cues video. RESULTS: Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05; females significantly decreased metabolism (-8.6%±10 whereas males tended to increase it (+5.5%±18. SPM analysis (Cocaine-cues vs Neutral in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001 whereas males showed increases in right inferior frontal gyrus (BA 44/45 (only at p<0.005. The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001 in frontal (BA 8, 9, 10, anterior cingulate (BA 24, 32, posterior cingulate (BA 23, 31, inferior parietal (BA 40 and thalamus (dorsomedial nucleus. CONCLUSIONS: Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from "control networks" (prefrontal, cingulate, inferior parietal, thalamus in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition. This highlights the importance of gender tailored interventions for cocaine addiction.

  13. Reduced Metabolism in Brain 'Control Networks' Following Cocaine-Cues Exposure in Female Cocaine Abusers

    International Nuclear Information System (INIS)

    Gender differences in vulnerability for cocaine addiction have been reported. Though the mechanisms are not understood, here we hypothesize that gender differences in reactivity to conditioned-cues, which contributes to relapse, are involved. To test this we compared brain metabolism (using PET and 18FDG) between female (n = 10) and male (n = 16) active cocaine abusers when they watched a neutral video (nature scenes) versus a cocaine-cues video. Self-reports of craving increased with the cocaine-cue video but responses did not differ between genders. In contrast, changes in whole brain metabolism with cocaine-cues differed by gender (p<0.05); females significantly decreased metabolism (-8.6% ± 10) whereas males tended to increase it (+5.5% ± 18). SPM analysis (Cocaine-cues vs Neutral) in females revealed decreases in frontal, cingulate and parietal cortices, thalamus and midbrain (p<0.001) whereas males showed increases in right inferior frontal gyrus (BA 44/45) (only at p<0.005). The gender-cue interaction showed greater decrements with Cocaine-cues in females than males (p<0.001) in frontal (BA 8, 9, 10), anterior cingulate (BA 24, 32), posterior cingulate (BA 23, 31), inferior parietal (BA 40) and thalamus (dorsomedial nucleus). Females showed greater brain reactivity to cocaine-cues than males but no differences in craving, suggesting that there may be gender differences in response to cues that are not linked with craving but could affect subsequent drug use. Specifically deactivation of brain regions from 'control networks' (prefrontal, cingulate, inferior parietal, thalamus) in females could increase their vulnerability to relapse since it would interfere with executive function (cognitive inhibition). This highlights the importance of gender tailored interventions for cocaine addiction.

  14. 直接脑控机器人接口技术%Direct Brain-controlled Robot Interface Technology

    Institute of Scientific and Technical Information of China (English)

    伏云发; 王越超; 李洪谊; 徐保磊; 李永程

    2012-01-01

    直接脑控机器人接口(Brain-controlled robot interface,BCRI)是一种新型的人-机器人接口技术,是脑-机器接口/脑-计算机接口 (Brain-machine interface,BMI/Brain-computer interface,BCI)在机器人控制领域的重要应用和研究方向.研究者相继在Nature、Science和其他重要国际期刊上报道了相关的实验研究和开发,目前已成为国际前沿研究热点.本文主要围绕BCRI中的控制策略、BMI/BCI模块与机器人多层控制模块的适应和融合、BCRI中的脑信号自适应分类算法以及人、BMI/BCI模块和机器人控制系统的三边自适应展开论述,分析了目前的研究情况、存在的局限和面临的若干重要问题,指出进一步的研究思路和方向.%Direct brain-controlled robot interface (BCRI) is a new type human-robot interface which is an important research and development direction for brain-machine interface (BMI) / brain-computer interface (BCI) in the robot control field. Many experimental researches and developments for BCRI were reported by Nature, Science and other important international journals and it has become an international frontier research hotspot. The paper mainly discussed the control strategies for BCRI, the adaptation and fusion between BMI/BCI module and robot multilayer control architecture module, the adaptive classification algorithms for brain signal used in BCRI and the trilateral adaptation among human, BMI/BCI module and robot control system. The current situation and limitation for BCRI and some important problems faced by BCRI were analyzed and the further research ideas and directions were also pointed out.

  15. Highly electrically conductive layered carbon derived from polydopamine and its functions in SnO2-based lithium ion battery anodes.

    Science.gov (United States)

    Kong, Junhua; Yee, Wu Aik; Yang, Liping; Wei, Yuefan; Phua, Si Lei; Ong, Hock Guan; Ang, Jia Ming; Li, Xu; Lu, Xuehong

    2012-10-25

    Thin carbonized polydopamine (C-PDA) coatings are found to have similar structures and electrical conductivities to those of multilayered graphene doped with heteroatoms. Greatly enhanced electrochemical properties are achieved with C-PDA-coated SnO(2) nanoparticles where the coating functions as a mechanical buffer layer and conducting bridge.

  16. 电能量采集系统功能实现浅析%An Analysis of the Functions of the Electric Energy Data Acquisition System

    Institute of Scientific and Technical Information of China (English)

    弋松立

    2011-01-01

    总体描述电能量采集系统的功能,并分析该系统各个组成部分的特性。%This essay generally describes the functions of the electric energy data acquisition system as well as analyzing the features of its components.

  17. Characterization of solar cells for space applications. Volume 14: Electrical characteristics of Hughes liquid phase epitaxy gallium arsenide solar cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1981-01-01

    Electrical characteristics of liquid phase epitaxy, P/N gallium aluminum arsenide solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature. The solar cells were exposed to 1 MeV electron fluences of, respectively, 0, one hundred trillion, one quadrillion, and ten quadrillion e/sq cm.

  18. Effect of exercise therapy combining electrical therapy and balance training on functional instability resulting from ankle sprain—focus on stability of jump landing

    OpenAIRE

    Yoshida, Takaki; Tanino, Yoshitsugu; Suzuki, Toshiaki

    2015-01-01

    [Purpose] Functional instability leads to a delay in the muscle reaction time and weakness of the peroneal muscles. The present study examined the effects of transcutaneous electrical nerve stimulation during balance exercise on patients with functional instability of the ankles, including the ability to land after jumping at the center of foot pressure. [Subjects] The subjects were seven males with a history of ankle sprain. All had a sprained ankle score of ≤80 points on Karlson’s functiona...

  19. A functional magnetic resonance imaging study of human brain in pain-related areas induced by electrical stimulation with different intensities

    Directory of Open Access Journals (Sweden)

    Yuan Wang

    2010-01-01

    Full Text Available Background: Pain-related studies have mainly been performed through traditional methods, which lack the rigorous analysis of anatomical locations. Functional magnetic resonance imaging (fMRI is a noninvasive method detecting neural activity, and has the ability to precisely locate related activations in vivo. Moreover, few studies have used painful stimulation of changed intensity to investigate relevant functioning nuclei in the human brain. Aim: This study mainly focused on the pain-related activations induced by electrical stimulation with different intensities using fMRI. Furthermore, the electrophysiological characteristics of different pain-susceptible-neurons were analyzed to construct the pain modulatory network, which was corresponding to painful stimulus of changed intensity. Materials and Methods: Twelve volunteers underwent functional scanning receiving different electrical stimulation. The data were collected and analyzed to generate the corresponding functional activation maps and response time curves related to pain. Results: The common activations were mainly located in several specific regions, including the secondary somatosensory cortex (SII, insula, anterior cingulate cortex (ACC, thalamus, and other cerebral regions. Moreover, innocuous electrical stimulation primarily activated the lateral portions of SII and thalamus, as well as the posterior insula, anterior ACC, whereas noxious electrical stimulation primarily activated the medial portions of SII and thalamus, as well as the anterior insula, the posterior ACC, with larger extensions and greater intensities. Conclusion: Several specified cerebral regions displayed different response patterns during electrical stimulation by means of fMRI, which implied that the corresponding pain-susceptible-neurons might process specific aspects of pain. Elucidation of functions on pain-related regions will help to understand the delicate pain modulation of human brain.

  20. Static electric multipole susceptibilities of the relativistic hydrogen-like atom in the ground state: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function

    CERN Document Server

    Szmytkowski, Radosław

    2016-01-01

    The ground state of the Dirac one-electron atom, placed in a weak, static electric field of definite $2^{L}$-polarity, is studied within the framework of the first-order perturbation theory. The Sturmian expansion of the generalized Dirac-Coulomb Green function [R. Szmytkowski, J. Phys. B 30 (1997) 825, erratum: 30 (1997) 2747] is used to derive closed-form analytical expressions for various far-field and near-nucleus static electric multipole susceptibilities of the atom. The far-field multipole susceptibilities --- the polarizabilities $\\alpha_{L}$, electric-to-magnetic cross-susceptibilities $\\alpha_{\\mathrm{E}L\\to\\mathrm{M}(L\\mp1)}$ and electric-to-toroidal-magnetic cross-susceptibilities $\\alpha_{\\mathrm{E}L\\to\\mathrm{T}L}$ --- are found to be expressible in terms of one or two non-terminating generalized hypergeometric functions ${}_{3}F_{2}$ with the unit argument. Counterpart formulas for the near-nucleus multipole susceptibilities --- the electric nuclear shielding constants $\\sigma_{\\mathrm{E}L\\to\\m...

  1. Automated Linear Function Submission-Based Double Auction as Bottom-up Real-Time Pricing in a Regional Prosumers’ Electricity Network

    Directory of Open Access Journals (Sweden)

    Tadahiro Taniguchi

    2015-07-01

    Full Text Available A linear function submission-based double auction (LFS-DA mechanism for a regional electricity network is proposed in this paper. Each agent in the network is equipped with a battery and a generator. Each agent simultaneously becomes a producer and consumer of electricity, i.e., a prosumer, and trades electricity in the regional market at a variable price. In the LFS-DA, each agent uses linear demand and supply functions when they submit bids and asks to an auctioneer in the regional market. The LFS-DA can achieve an exact balance between electricity demand and supply for each time slot throughout the learning phase and was shown capable of solving the primal problem of maximizing the social welfare of the network without any central price setter, e.g., a utility or a large electricity company, in contrast with conventional real-time pricing (RTP. This paper presents a clarification of the relationship between the RTP algorithm derived on the basis of a dual decomposition framework and LFS-DA. Specifically, we proved that the changes in the price profile of the LFS-DA mechanism are equal to those achieved by the RTP mechanism derived from the dual decomposition framework, except for a constant factor.

  2. Europe-United States: two diverging evolutions of electricity restructuring? a prospective study on the functioning and the regulation of electrical markets on both sides of the Atlantic

    International Nuclear Information System (INIS)

    On both sides of the Atlantic, the same broad purpose was at the heart of electricity restructuring policies: substituting competition to the monopolistic organisation as a means of increased efficiency, and transforming sets of local markets into large continental-wide integrated markets. The current diversity between European and American systems is thus intriguing. The relative homogeneity of electrical systems in the old continent, which is being reinforced by the gradual though delicate elaboration of shared principles on the general organisation of the electricity industry at the European level, compares to a genuine diversity on the American side, where each State remains responsible for conducting its own restructuring policy, even if similar rules on wholesale markets are acknowledged and implemented at a federal level. Yet Europe and the United States face the same kind of issues regarding the future of the energy industry: which status for grid operators, how to respond to growing concerns on security of supply, what to do to mitigate the sharp increase in energy prices? Evidence thereof are the similar attempts by some States to retain direct price control methods, rather than to bank on the virtues of competition to prompt investments in generation and lead prices to drop. It currently appears that the answers to these shared challenges are not converging. On behalf of a comparatively strong freedom of action relatively to the initial competitive paradigm, the array of polio/ responses available in the United States seems broader than in Europe, where the approach recommended by the European Commission consists of further deepening the initial model without altering it. The future will show whether that trend is lasting, or if two structurally different models can emerge from such differences. (authors)

  3. Event-Related Beta EEG Changes During Active, Passive Movement and Functional Electrical Stimulation of the Lower Limb.

    Science.gov (United States)

    Qiu, Shuang; Yi, Weibo; Xu, Jiapeng; Qi, Hongzhi; Du, Jingang; Wang, Chunfang; He, Feng; Ming, Dong

    2016-02-01

    A number of electroencephalographic (EEG) studies have reported on event-related desynchronization/synchronization (ERD/ERS) during active movements, passive movements, and the movements induced by functional electrical stimulation (FES). However, the quantitative differences in ERD values and affected frequency bands associated with the lower limb have not been discussed. The goal of this paper was to quantitatively compare the ERD patterns during active movement, passive movement and FES-induced movement of the lower limb. 64-channel EEG signals were recorded to investigate the brain oscillatory patterns during active movement, passive movement and FES-induced movement of the lower limb in twelve healthy subjects. And passive movement and FES-induced movement were also performed in a hemiplegic stroke patient. For healthy subjects, FES-induced movement presented significantly higher characteristic frequency of central beta ERD while there was no significant difference in ERD values compared with active or passive movement. Meanwhile, beta ERD values of FES-induced movement were significantly correlated with those of active movement, and spatial distribution of beta ERD pattern for FES-induced movement was more correlated with that for active movement. In addition, the stroke patient presented central ERD patterns during FES-induced movement, while no ERD with similar frequencies could be found during passive movement. This work implies that the EEG oscillatory pattern under FES-induced movement tends more towards active movement instead of passive movement. The quantification of ERD patterns could be expected as a potential technique to evaluate the brain response during FES-induced movement. PMID:26441422

  4. Functional electrical stimulation mediated by iterative learning control and 3D robotics reduces motor impairment in chronic stroke

    Directory of Open Access Journals (Sweden)

    Meadmore Katie L

    2012-06-01

    Full Text Available Abstract Background Novel stroke rehabilitation techniques that employ electrical stimulation (ES and robotic technologies are effective in reducing upper limb impairments. ES is most effective when it is applied to support the patients’ voluntary effort; however, current systems fail to fully exploit this connection. This study builds on previous work using advanced ES controllers, and aims to investigate the feasibility of Stimulation Assistance through Iterative Learning (SAIL, a novel upper limb stroke rehabilitation system which utilises robotic support, ES, and voluntary effort. Methods Five hemiparetic, chronic stroke participants with impaired upper limb function attended 18, 1 hour intervention sessions. Participants completed virtual reality tracking tasks whereby they moved their impaired arm to follow a slowly moving sphere along a specified trajectory. To do this, the participants’ arm was supported by a robot. ES, mediated by advanced iterative learning control (ILC algorithms, was applied to the triceps and anterior deltoid muscles. Each movement was repeated 6 times and ILC adjusted the amount of stimulation applied on each trial to improve accuracy and maximise voluntary effort. Participants completed clinical assessments (Fugl-Meyer, Action Research Arm Test at baseline and post-intervention, as well as unassisted tracking tasks at the beginning and end of each intervention session. Data were analysed using t-tests and linear regression. Results From baseline to post-intervention, Fugl-Meyer scores improved, assisted and unassisted tracking performance improved, and the amount of ES required to assist tracking reduced. Conclusions The concept of minimising support from ES using ILC algorithms was demonstrated. The positive results are promising with respect to reducing upper limb impairments following stroke, however, a larger study is required to confirm this.

  5. Study on the electric conduction function of carbon black and carbon fiber diphasic electrically conductive concrete%炭黑碳纤维复相导电混凝土的导电性能研究

    Institute of Scientific and Technical Information of China (English)

    卢珍; 吴献; 杨昆

    2014-01-01

    It aimed at the research on the electric conduction function carbon black and carbon fiber diphasic electrically conductive concrete,and analyse the change of resistivity.The methodology adopted as theoretical basis and experimental basis can be used in deicing or snow-melting in future.Carbon black and carbon fiber as the electric conduction is used to improve the electric conduction function of concrete.Conduct the experiment of the electric conduction function of carbon black and carbon fiber diphasic electrically conductive con-crete.The effect of temperature,humidity and plus voltage on resistivity of carbon black and carbon fiber diphasic electricall conductive concrete was analysed.When environment chang,the electric conduction function of concrete will chang too.As the rise of temperature the experimental results showed that the resistivity of carbon black and carbon fiber diphasic electrically conductive concrete will reduct in a certain degree.The resistivity in dry state was higher than the state of wet. As the rise of plus voltage the resistivity of carbon black and car-bon fiber diphasic electrically conductive concrete will reduct in a certain degree.When the voltage is to a certain number ,the resistivity trend to be stabile.%研究了炭黑碳纤维复相导电混凝土的导电性能,分析了导电混凝土的电阻率变化,为实际应用于道路融雪化冰提供理论依据与试验依据。利用纳米导电炭黑和碳纤维作为导电相来改善混凝土的导电性能,进行炭黑碳纤维复相导电混凝土的导电性能试验,分析环境温度、干湿度和外加电压对炭黑碳纤维导电混凝土电阻率的影响。导电混凝土的电阻率受温度、湿度和外加电压的影响,当环境条件发生变化时,导电混凝土的导电性能也会发生变化。炭黑碳纤维复相导电混凝土的电阻率随着温度的升高出现一定程度的减小;干燥状态下的电阻率高于潮湿

  6. A hybrid self-adaptive Particle Swarm Optimization–Genetic Algorithm–Radial Basis Function model for annual electricity demand prediction

    International Nuclear Information System (INIS)

    Highlights: • A hybrid self-adaptive PSO–GA-RBF model is proposed for electricity demand prediction. • Each mixed-coding particle is composed by two coding parts of binary and real. • Five independent variables have been selected to predict future electricity consumption in Wuhan. • The proposed model has a simpler structure or higher estimating precision than other ANN models. • No matter what the scenario, the electricity consumption of Wuhan will grow rapidly. - Abstract: The present study proposes a hybrid Particle Swarm Optimization and Genetic Algorithm optimized Radial Basis Function (PSO–GA-RBF) neural network for prediction of annual electricity demand. In the model, each mixed-coding particle (or chromosome) is composed of two coding parts, binary and real, which optimizes the structure of the RBF by GA operation and the parameters of the basis and weights by a PSO–GA implementation. Five independent variables have been selected to predict future electricity consumption in Wuhan by using optimized networks. The results shows that (1) the proposed PSO–GA-RBF model has a simpler network structure (fewer hidden neurons) or higher estimation precision than other selected ANN models; and (2) no matter what the scenario, the electricity consumption of Wuhan will grow rapidly at average annual growth rates of about 9.7–11.5%. By 2020, the electricity demand in the planning scenario, the highest among the scenarios, will be 95.85 billion kW h. The lowest demand is estimated for the business-as-usual scenario, and will be 88.45 billion kW h

  7. Hybrid neuroprosthesis for the upper limb: combining brain-controlled neuromuscular stimulation with a multi-joint arm exoskeleton

    Directory of Open Access Journals (Sweden)

    Florian Grimm

    2016-08-01

    Full Text Available Brain-machine interface-controlled (BMI neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related range of motion and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. Neuromuscular electrical stimulation was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD and electromyography (EMG activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e. induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p=0.028 or EMG (p=0.021 modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related range of motion (p=0.009 and the movement-related brain modulation (p=0

  8. Three-dimensional analytical solution for a transversely isotropic functionally graded piezoelectric circular plate subject to a uniform electric potential difference

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper studies the problem of a functionally graded piezoelectric circular plate subjected to a uniform electric potential difference between the upper and lower surfaces. By assuming the generalized displacements in appropriate forms,five differential equations governing the generalized displacement functions are derived from the equilibrium equations. These displacement functions are then obtained in an explicit form,which still involve four undetermined integral constants,through a step-by-step integration which properly incorporates the boundary conditions at the upper and lower surfaces. The boundary conditions at the cylindrical surface are then used to determine the integral constants. Hence,three-dimen sional analytical solutions for electrically loaded functionally graded piezoelectric circular plates with free or simply-supported edge are completely determined. These solutions can account for an arbitrary material variation along the thickness,and thus can be readily degenerated into those for a homogenous plate. A numerical example is finally given to show the validity of the analysis,and the effect of material inhomogeneity on the elastic and electric fields is discussed.

  9. Band Gap Modulation of Bilayer MoS2 Under Strain Engineering and Electric Field: A Density Functional Theory

    Science.gov (United States)

    Nguyen, Chuong V.; Hieu, Nguyen N.; Ilyasov, Victor V.

    2016-08-01

    In this work, we investigate band-gap tuning in bilayer MoS2 by an external electric field and by applied biaxial strain. Our calculations show that the band gaps of bilayer MoS2 can be tuned by the perpendicular electric field or biaxial strain. The band gaps of bilayer MoS2 decrease with increasing applied electric field or biaxial strain. When the electric field was introduced, electronic levels are split due to the separation of the valence sub-band and the conduction sub-band states. Our calculations also show that the change in the band gap of bilayer MoS2 is due to the separation of electronic levels by electric field via the Stark effect. At the electric field E_{Field} = 5.5 V/nm or biaxial strain ɛ = 15%, bilayer MoS2 becomes metallic. The semiconductor-metal phase transition in bilayer MoS2 plays an important role in its application for nanodevices.

  10. Band Gap Modulation of Bilayer MoS2 Under Strain Engineering and Electric Field: A Density Functional Theory

    Science.gov (United States)

    Nguyen, Chuong V.; Hieu, Nguyen N.; Ilyasov, Victor V.

    2016-05-01

    In this work, we investigate band-gap tuning in bilayer MoS2 by an external electric field and by applied biaxial strain. Our calculations show that the band gaps of bilayer MoS2 can be tuned by the perpendicular electric field or biaxial strain. The band gaps of bilayer MoS2 decrease with increasing applied electric field or biaxial strain. When the electric field was introduced, electronic levels are split due to the separation of the valence sub-band and the conduction sub-band states. Our calculations also show that the change in the band gap of bilayer MoS2 is due to the separation of electronic levels by electric field via the Stark effect. At the electric field E_{Field} = 5.5 V/nm or biaxial strain \\varepsilon = 15%, bilayer MoS2 becomes metallic. The semiconductor-metal phase transition in bilayer MoS2 plays an important role in its application for nanodevices.

  11. Functional electrical stimulation increases neural stem/progenitor cell proliferation and neurogenesis in the subventricular zone of rats with stroke

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-hua; XIANG Yun; YAN Tie-bin; TAN Zhi-mei; LI Sheng-huo; HE Xiao-kuo

    2013-01-01

    Background Functional electrical stimulation (FES) is known to promote the recovery of motor function in rats with ischemia and to upregulate the expression of growth factors which support brain neurogenesis.In this study,we investigated whether postischemic FES could improve functional outcomes and modulate neurogenesis in the subventricular zone (SVZ) after focal cerebral ischemia.Methods Adult male Sprague-Dawley rats with permanent middle cerebral artery occlusion (MCAO) were randomly assigned to the control group,the placebo stimulation group,and the FES group.The rats in each group were further assigned to one of four therapeutic periods (1,3,7,or 14 days).FES was delivered 48 hours after the MCAO procedure and divided into two 10-minute sessions on each day of treatment with a 10-minute rest between them.Two intraperitoneal injections of bromodeoxyuridine (BrdU) were given 4 hours apart every day beginning 48 hours after the MCAO.Neurogenesis was evaluated by immunofluorescence staining.Wnt-3 which is strongly implicated in the proliferation and differentiation of neural stem cells (NSCs) was investigated by Western blotting analysis.The data wera subjected to oneway analysis of variance (ANOVA),followed by a Tukey/Kramer or Dunnett post hoc test.Results FES significantly increased the number of BrdU-positive cells and BrdU/glial flbrillary acidic protein doublepositive neural progenitor cells in the SVZ on days 7 and 14 of the treatment (P <0.05).The number of BrdU/doublecortin (DCX) double-positive migrating neuroblast cells in the ipsilateral SVZ on day 14 of the FES treatment group ((522.77±33.32) cells/mm2) was significantly increased compared with the control group ((262.58±35.11) cells/mm2,P <0.05) and the placebo group ((266.17±47.98) cells/mm2,P <0.05).However,only a few BrdU/neuron-specific nuclear protein-positive cells were observed by day 14 of the treatment.At day 7,Wnt-3 was upregulated in the ipsilateral SVZs of the rats receiving

  12. Appearance of perfect amorphous linear bulk polyethylene under applied electric field and the analysis by radial distribution function and direct tunneling effect.

    Science.gov (United States)

    Zhang, Rong; Bin, Yuezhen; Yang, Wenxiao; Fan, Shaoyan; Matsuo, Masaru

    2014-02-27

    Without melting flow, linear ultrahigh molecular weight polyethylene (UHMWPE) provided X-ray intensity curve from only amorphous halo at 129.0 °C (surface temperature, Ts arisen by Joule heat) lower than the conventionally known melting point 145.5 °C on applying electric field to UHMWPE-nickel-coated carbon fiber (NiCF) composite. Such surprising phenomenon was analyzed by simultaneous measurements of X-ray intensity, electric current, and Ts as a function of time. The calculated radial distribution function revealed the amorphous structure with disordered chain arrangement. The appearance of such amorphous phase was arisen by the phenomenon that the transferring electrons between overlapped adjacent NiCFs by tunneling effect struck together with X-ray photons and some of the transferring electron flown out from the gap to UHMWPE matrix collided against carbon atoms of UHMWPE. The impact by the collision caused disordering chain arrangement in crystal grains. PMID:24479438

  13. Magnetic-field-induced electric quadrupole moments for relativistic hydrogenlike atoms: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function

    CERN Document Server

    Stefańska, Patrycja

    2016-01-01

    We consider a Dirac one-electron atom placed in a weak, static, uniform magnetic field. We show that, to the first order in the strength B of the external field, the only electric multipole moments, which are induced by the perturbation in the atom, are those of an even order. Using the Sturmian expansion of the generalized Dirac-Coulomb Green function [R. Szmytkowski, J. Phys. B 30, 825 (1997); 30, 2747(E) (1997)], we derive a closed-form expression for the electric quadrupole moment induced in the atom in an arbitrary discrete energy eigenstate. The result, which has the form of a double finite sum involving the generalized hypergeometric functions 3F2 of the unit argument, agrees with the earlier relativistic formula for that quantity, obtained by us for the ground state of the atom.

  14. Facile synthesis of polypyrrole functionalized nickel foam with catalytic activity comparable to Pt for the poly-generation of hydrogen and electricity

    Science.gov (United States)

    Tang, Tiantian; Li, Kan; Shen, Zhemin; Sun, Tonghua; Wang, Yalin; Jia, Jinping

    2016-01-01

    Polypyrrole functionalized nickel foam is facilely prepared through the potentiostatic electrodeposition. The PPy-functionalized Ni foam functions as a hydrogen-evolution cathode in a rotating disk photocatalytic fuel cell, in which hydrogen energy and electric power are generated by consuming organic wastes. The PPy-functionalized Ni foam cathode exhibits stable catalytic activities after thirteen continuous runs. Compared with net or plate structure, the Ni foam with a unique three-dimensional reticulate structure is conducive to the electrodeposition of PPy. Compared with Pt-group electrode, PPy-coated Ni foam shows a satisfactory catalytic performance for the H2 evolution. The combination of PPy and Ni forms a synergistic effect for the rapid trapping and removal of proton from solution and the catalytic reduction of proton to hydrogen. The PPy-functionalized Ni foam could be applied in photocatalytic and photoelectrochemical generation of H2. In all, we report a low cost, high efficient and earth abundant PPy-functionalized Ni foam with a satisfactory catalytic activities comparable to Pt for the practical application of poly-generation of hydrogen and electricity.

  15. Trunk muscle co-activation using functional electrical stimulation modifies center of pressure fluctuations during quiet sitting by increasing trunk stiffness

    OpenAIRE

    Milosevic, Matija; Masani, Kei; Wu, Noel; McConville, Kristiina M. V.; Popovic, Milos R.

    2015-01-01

    Background The purpose of this study was to examine the impact of functional electrical stimulation (FES) induced co-activation of trunk muscles during quiet sitting. We hypothesized that FES applied to the trunk muscles will increase trunk stiffness. The objectives of this study were to: 1) compare the center of pressure (COP) fluctuations during unsupported and FES-assisted quiet sitting - an experimental study and; 2) investigate how FES influences sitting balance - an analytical (simulati...

  16. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    Science.gov (United States)

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  17. Hybrid Neuroprosthesis for the Upper Limb: Combining Brain-Controlled Neuromuscular Stimulation with a Multi-Joint Arm Exoskeleton.

    Science.gov (United States)

    Grimm, Florian; Walter, Armin; Spüler, Martin; Naros, Georgios; Rosenstiel, Wolfgang; Gharabaghi, Alireza

    2016-01-01

    Brain-machine interface-controlled (BMI) neurofeedback training aims to modulate cortical physiology and is applied during neurorehabilitation to increase the responsiveness of the brain to subsequent physiotherapy. In a parallel line of research, robotic exoskeletons are used in goal-oriented rehabilitation exercises for patients with severe motor impairment to extend their range of motion (ROM) and the intensity of training. Furthermore, neuromuscular electrical stimulation (NMES) is applied in neurologically impaired patients to restore muscle strength by closing the sensorimotor loop. In this proof-of-principle study, we explored an integrated approach for providing assistance as needed to amplify the task-related ROM and the movement-related brain modulation during rehabilitation exercises of severely impaired patients. For this purpose, we combined these three approaches (BMI, NMES, and exoskeleton) in an integrated neuroprosthesis and studied the feasibility of this device in seven severely affected chronic stroke patients who performed wrist flexion and extension exercises while receiving feedback via a virtual environment. They were assisted by a gravity-compensating, seven degree-of-freedom exoskeleton which was attached to the paretic arm. NMES was applied to the wrist extensor and flexor muscles during the exercises and was controlled by a hybrid BMI based on both sensorimotor cortical desynchronization (ERD) and electromyography (EMG) activity. The stimulation intensity was individualized for each targeted muscle and remained subthreshold, i.e., induced no overt support. The hybrid BMI controlled the stimulation significantly better than the offline analyzed ERD (p = 0.028) or EMG (p = 0.021) modality alone. Neuromuscular stimulation could be well integrated into the exoskeleton-based training and amplified both the task-related ROM (p = 0.009) and the movement-related brain modulation (p = 0.019). Combining a hybrid BMI with neuromuscular stimulation

  18. Effects of Robot-assisted Gait Training Combined with Functional Electrical Stimulation on Recovery of Locomotor Mobility in Chronic Stroke Patients: A Randomized Controlled Trial.

    Science.gov (United States)

    Bae, Young-Hyeon; Ko, Young Jun; Chang, Won Hyuk; Lee, Ju Hyeok; Lee, Kyeong Bong; Park, Yoo Jung; Ha, Hyun Geun; Kim, Yun-Hee

    2014-12-01

    [Purpose] The purpose of the present study was to investigate the effects of robot-assisted gait training combined with functional electrical stimulation on locomotor recovery in patients with chronic stroke. [Subjects] The 20 subjects were randomly assigned into either an experimental group (n = 10) that received a combination of robot-assisted gait training and functional electrical stimulation on the ankle dorsiflexor of the affected side or a control group (n = 10) that received robot-assisted gait training only. [Methods] Both groups received the respective therapies for 30 min/day, 3 days/week for 5 weeks. The outcome was measured using the Modified Motor Assessment Scale (MMAS), Timed Up-and-Go Test (TUG), Berg Balance Scale (BBS), and gait parameters through gait analysis (Vicon 370 motion analysis system, Oxford Metrics Ltd., Oxford, UK). All the variables were measured before and after training. [Results] Step length and maximal knee extension were significantly greater than those before training in the experimental group only. Maximal Knee flexion showed a significant difference between the experimental and control groups. The MMAS, BBS, and TUG scores improved significantly after training compared with before training in both groups. [Conclusion] We suggest that the combination of robot-assisted gait training and functional electrical stimulation encourages patients to actively participate in training because it facilitates locomotor recovery without the risk of adverse effects.

  19. Activity-dependent plasticity of electrical synapses: increasing evidence for its presence and functional roles in the mammalian brain.

    Science.gov (United States)

    Haas, Julie S; Greenwald, Corey M; Pereda, Alberto E

    2016-01-01

    Gap junctions mediate electrical synaptic transmission between neurons. While the actions of neurotransmitter modulators on the conductance of gap junctions have been extensively documented, increasing evidence indicates they can also be influenced by the ongoing activity of neural networks, in most cases via local interactions with nearby glutamatergic synapses. We review here early evidence for the existence of activity-dependent regulatory mechanisms as well recent examples reported in mammalian brain. The ubiquitous distribution of both neuronal connexins and the molecules involved suggest this phenomenon is widespread and represents a property of electrical transmission in general. PMID:27230776

  20. Comparison of the Effect of Exercise Therapy with Transcutaneous Electrical Nerve Stimulation on Improvement of Pain and Function in Patients with Patellofemoral Pain Syndrome

    Directory of Open Access Journals (Sweden)

    A Akbari

    2008-04-01

    Full Text Available ABSTRACT: Introduction & Objective: One of the most common disorders of the knee joint in adult is patellofemoral pain syndrome. Sometimes it becomes chronic and causes activity limitation. This study aimed to compare the efficacy of exercise therapy with Transcutaneous Electrical Nerve Stimulation on improvement of pain intensity, knee function, muscle atrophy and range of knee flexion. Materials & Methods: This double-blind, randomized clinical trial was carried out in Zahedan Razmejo-Moghadam Physiotherapy Clinic, in 2007. Thirty-two patients with patellofemoral pain syndrome were recruited through simple non-probability sampling. Subjects were randomly assigned to one of the equal groups, exercise therapy (including hip, knee, and leg muscles strengthening and stretching exercises or electrical stimulation group. Before and after intervention, we assessed pain through Visual Analog Scale (VAS (ordinal, function (ordinal with Knee Injury and Osteoarthritis Outcome Score (KOOS, thigh circumference with tape measure (centimeter and range of knee flexion with goniometer (degree. A 10 session treatment program, three sessions per week and one hour per session was performed for both groups. Independent t-test or Mann-Whitney U and paired t-test or Wilcoxon were used for comparison between the pretreatment and post treatment results between groups and within groups, in SPSS software, respectively. Results: The mean total score of knee function increased from 100.53±19.25 to 130.87±18.25 in the electrical stimulation group and from 107.67±22.69 to 131.47±15.11 in the exercise therapy group (p=0.001. The mean score of knee function subscales including symptoms, pain, functional limitation, recreational activity, and life style improved in both groups (p<0.05. The pain score and range of knee flexion improved in both groups (p<0.05. After treatment, range of knee flexion significantly increased in the exercise group compared with the electrical

  1. From the intrinsic properties to the functional role of a neuron phenotype: an example from electric fish during signal trade-off.

    Science.gov (United States)

    Nogueira, Javier; Caputi, Angel A

    2013-07-01

    This review deals with the question: what is the relationship between the properties of a neuron and the role that the neuron plays within a given neural circuit? Answering this kind of question requires collecting evidence from multiple neuron phenotypes and comparing the role of each type in circuits that perform well-defined computational tasks. The focus here is on the spherical neurons in the electrosensory lobe of the electric fish Gymnotus omarorum. They belong to the one-spike-onset phenotype expressed at the early stages of signal processing in various sensory modalities and diverse taxa. First, we refer to the one-spike neuron intrinsic properties, their foundation on a low-threshold K(+) conductance, and the potential roles of this phenotype in different circuits within a comparative framework. Second, we present a brief description of the active electric sense of weakly electric fish and the particularities of spherical one-spike-onset neurons in the electrosensory lobe of G. omarorum. Third, we introduce one of the specific tasks in which these neurons are involved: the trade-off between self- and allo-generated signals. Fourth, we discuss recent evidence indicating a still-undescribed role for the one-spike phenotype. This role deals with the blockage of the pathway after being activated by the self-generated electric organ discharge and how this blockage favors self-generated electrosensory information in the context of allo-generated interference. Based on comparative analysis we conclude that one-spike-onset neurons may play several functional roles in animal sensory behavior. There are specific adaptations of the neuron's 'response function' to the circuit and task. Conversely, the way in which a task is accomplished depends on the intrinsic properties of the neurons involved. In short, the role of a neuron within a circuit depends on the neuron and its functional context.

  2. From the intrinsic properties to the functional role of a neuron phenotype: an example from electric fish during signal trade-off.

    Science.gov (United States)

    Nogueira, Javier; Caputi, Angel A

    2013-07-01

    This review deals with the question: what is the relationship between the properties of a neuron and the role that the neuron plays within a given neural circuit? Answering this kind of question requires collecting evidence from multiple neuron phenotypes and comparing the role of each type in circuits that perform well-defined computational tasks. The focus here is on the spherical neurons in the electrosensory lobe of the electric fish Gymnotus omarorum. They belong to the one-spike-onset phenotype expressed at the early stages of signal processing in various sensory modalities and diverse taxa. First, we refer to the one-spike neuron intrinsic properties, their foundation on a low-threshold K(+) conductance, and the potential roles of this phenotype in different circuits within a comparative framework. Second, we present a brief description of the active electric sense of weakly electric fish and the particularities of spherical one-spike-onset neurons in the electrosensory lobe of G. omarorum. Third, we introduce one of the specific tasks in which these neurons are involved: the trade-off between self- and allo-generated signals. Fourth, we discuss recent evidence indicating a still-undescribed role for the one-spike phenotype. This role deals with the blockage of the pathway after being activated by the self-generated electric organ discharge and how this blockage favors self-generated electrosensory information in the context of allo-generated interference. Based on comparative analysis we conclude that one-spike-onset neurons may play several functional roles in animal sensory behavior. There are specific adaptations of the neuron's 'response function' to the circuit and task. Conversely, the way in which a task is accomplished depends on the intrinsic properties of the neurons involved. In short, the role of a neuron within a circuit depends on the neuron and its functional context. PMID:23761463

  3. Modelling motor cortex stimulation for chronic pain control. electrical potential field, activating functions and responses of simple nerve fibre models

    NARCIS (Netherlands)

    Manola, L.; Roelofsen, B.H.; Holsheimer, J.; Marani, E.; Geelen, J.A.G.

    2005-01-01

    This computer modelling study on motor cortex stimulation (MCS) introduced a motor cortex model, developed to calculate the imposed electrical potential field characteristics and the initial response of simple fibre models to stimulation of the precentral gyrus by an epidural electrode, as applied i

  4. Potential of M-Wave Elicited by Double Pulse for Muscle Fatigue Evaluation in Intermittent Muscle Activation by Functional Electrical Stimulation for Motor Rehabilitation

    Directory of Open Access Journals (Sweden)

    Naoto Miura

    2016-01-01

    Full Text Available Clinical studies on application of functional electrical stimulation (FES to motor rehabilitation have been increasing. However, muscle fatigue appears early in the course of repetitive movement production training by FES. Although M-wave variables were suggested to be reliable indices of muscle fatigue in long lasting constant electrical stimulation under the isometric condition, the ability of M-wave needs more studies under intermittent stimulation condition, because the intervals between electrical stimulations help recovery of muscle activation level. In this paper, M-waves elicited by double pulses were examined in muscle fatigue evaluation during repetitive movements considering rehabilitation training with surface electrical stimulation. M-waves were measured under the two conditions of repetitive stimulation: knee extension force production under the isometric condition and the dynamic movement condition by knee joint angle control. Amplitude of M-wave elicited by the 2nd pulse of a double pulse decreased during muscle fatigue in both measurement conditions, while the change in M-waves elicited by single pulses in a stimulation burst was not relevant to muscle fatigue in repeated activation with stimulation interval of 1 s. Fatigue index obtained from M-waves elicited by 2nd pulses was suggested to provide good estimation of muscle fatigue during repetitive movements with FES.

  5. 3D Modelling and monitoring of denervated muscle under Functional Electrical Stimulation treatment and associated bone structural changes

    Directory of Open Access Journals (Sweden)

    Paolo Gargiulo

    2011-03-01

    Full Text Available A novel clinical rehabilitation method for patients who have permanent and non recoverable muscle denervation in the legs was developed in the frame of the European Project RISE. The technique is based on FES and the project results shows, in these severely disabled patients, restoration of muscle tissue and function. This study propose novel methods based on image processing technique and medical modelling to monitor growth in denervated muscle treated with FES. Geometrical and structural changes in muscle and bone are studied and modelled. Secondary effects on the bone mineral density produced by the stimulation treatment and due the elicited muscle contraction are also investigated. The restoration process in DDM is an important object of discussion since there isn’t yet a complete understanding of the mechanisms regulating growth in denervated muscle. This study approaches the problem from a macroscopic point of view, developing 3-dimensional models of the whole stimulated muscles and following changes in volume, geometry and density very accurately. The method is based on the acquisition of high resolution Spiral CT scans from patients who have long-term flaccid paraplegia and the use of special image processing tools allowing tissue discriminations and muscle segmentation. Three patients were measured at different points of time during 4 years of electrical stimulation treatment. In this study is quantitatively demonstrated the influences of FES treatment on the different quadriceps bellies. The rectus femoris muscle is positioned in the middle of the quadriceps and responds (in general better to stimulation. In a patient with abundant adipose tissue surrounding the quadriceps, rectus femoris almost doubled the volume during the FES treatment while in the other bellies the changes measured were minimal. The analysis of the density shows clearly a restoration of the muscular structure in the growing muscle. The remarkable increase of

  6. A NEW MODEL AND IMPROVED CABLE FUNCTION FOR REPRESENTING THE ACTIVATING PERIPHERAL NERVES BY A TRANSVERSE ELECTRIC FIELD DURING MAGNETIC STIMULATION

    Institute of Scientific and Technical Information of China (English)

    Yu Hui; Zheng Chongxun; Wang Haiyan; Wang Yi

    2005-01-01

    Objective Previous studies of peripheral nerves activation during magnetic stimulation have focused almost exclusively on the cause of high external parallel electric field along the nerves, whereas the effect of the transverse component has been ignored. In the present paper, the classical cable function is modified to represent the excitation of peripheral nerves stimulated by a transverse electric field during magnetic stimulation. Methods Responses of the Ranvier nodes to a transverse-field are thoroughly investigated by mathematic simulation. Results The simulation demonstrates that the excitation results from the net inward current driven by an external field. Based on a two-stage process, a novel model is introduced to describe peripheral nerves stimulated by a transverse-field. Based on the new model, the classical cable function is modified. Conclusion Using this modified cable equation, the excitation threshold of peripheral nerves in a transverse field during MS is obtained. The modified cable equation can be used to represent the response of peripheral nerves by an arbitrary electric field.

  7. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    Science.gov (United States)

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out. PMID:25741878

  8. Covalent functionalization of single-walled carbon nanotubes with anthracene by green chemical approach and their temperature dependent magnetic and electrical conductivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Hariharasubramanian, A. [Organic Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamilnadu (India); Dominic Ravichandran, Y., E-mail: ydominic64@yahoo.co.in [Organic Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamilnadu (India); Rajesh, R.; Rajendra Kumar, K. [Organic Chemistry Division, School of Advanced Sciences, VIT University, Vellore 632014, Tamilnadu (India); Kanagaraj, M.; Arumugam, S. [Centre for High Pressure Research, School of Physics, Bharathidasan University, Thiruchirapalli 620024 (India)

    2014-01-15

    Single-walled carbon nanotubes (SWCNTs) were covalently functionalized with anthracene in molten urea by a green chemical approach. The anthracene functionalized single-walled carbon nanotubes (Ant-f-SWCNTs) were examined along with SWCNTs, using Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, powder X-Ray diffraction (XRD), and scanning, and transmission electron microscopy. The observations revealed the functionalization of SWCNTs by anthracene. The temperature dependent magnetization (300–5 K) and electrical resistivity were also measured for both SWCNTs and Ant-f-SWCNTs. The electrical resistivity of Ant-f-SWCNTs at 300 K was found to be 1.27 KΩm, which is much lower than 388.55 KΩm for pristine. This indicated a 300 fold increase in conductivity at room temperature for Ant-f-SWCNTs when compared to SWCNTs. The temperature dependence of the conductivity provided an indication of the semiconducting behaviour. - Highlights: • SWCNTs were functionalized using 2-aminoanthracene by green chemistry. • Characterized by FTIR, Raman, XRD, SEM and TEM. • Temperature dependent magnetization and conductivity were investigated. • 300 fold increase in conductivity was observed for Ant-f-SWCNTs. • Semiconductor behaviour was observed in the case of Ant-f-SWCNTs.

  9. Intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation for preservation of facial nerve function in patients with large acoustic neuroma

    Institute of Scientific and Technical Information of China (English)

    LIU Bai-yun; TIAN Yong-ji; LIU Wen; LIU Shu-ling; QIAO Hui; ZHANG Jun-ting; JIA Gui-jun

    2007-01-01

    Background Although various monitoring techniques have been used routinely in the treatment of the lesions in the skull base, iatrogenic facial paresis or paralysis remains a significant clinical problem. The aim of this study was to investigate the effect of intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation on preservation of facial nerve function.Method From January to November 2005, 19 patients with large acoustic neuroma were treated using intraoperative facial motor evoked potentials monitoring with transcranial electrical stimulation (TCEMEP) for preservation of facial nerve function. The relationship between the decrease of MEP amplitude after tumor removal and the postoperative function of the facial nerve was analyzed.Results MEP amplitude decreased more than 75% in 11 patients, of which 6 presented significant facial paralysis (H-B grade 3), and 5 had mild facial paralysis (H-B grade 2). In the other 8 patients, whose MEP amplitude decreased less than 75%, 1 experienced significant facial paralysis, 5 had mild facial paralysis, and 2 were normal.Conclusions Intraoperative TCEMEP can be used to predict postoperative function of the facial nerve. The decreased MEP amplitude above 75 % is an alarm point for possible severe facial paralysis.

  10. Performance of a direct steam generation solar thermal power plant for electricity production as a function of the solar multiple

    OpenAIRE

    Montes Pita, María José; Abánades Velasco, Alberto; Martínez-Val Peñalosa, Jose Maria

    2009-01-01

    This paper describes the influence of the solar multiple on the annual performance of parabolic trough solar thermal power plants with direct steam generation (DSG). The reference system selected is a 50 M We DSG power plant, with thermal storage and auxiliary natural gas-fired boiler. It is considered that both systems are necessary for an optimum coupling to the electricity grid. Although thermal storage is an opening issue for DSG technology, it gives an additional degree of freedom for pl...

  11. Structure function analysis of changes found in the ELF electric field prior to the strong earthquakes and in other highly perturbed regions.

    Science.gov (United States)

    Kosciesza, Malgorzata; Blecki, Jan; Wronowski, Roman; Parrot, Michel

    2014-05-01

    We report the structure function analysis of changes found in electric field in the ELF range plasma turbulence registered by the DEMETER satellite in the ionosphere over epicenter region of three earthquakes. First one took place on 16th of December 2006 in Ping Tong Region with magnitude 7.1. Second was earthquake with magnitude 6.3 in L'Aquila on 6th April 2009. The last one took place on 27th of February 2010 in Offshore of Chile with magnitude 8.8. The structure functions were calculated also for the Polar CUSP region and equatorial spread F region. Basic studies of the turbulent processes were conducted with use of higher order spectra and higher order statistics. The structure function analysis was performed to locate and check if there are intermittent behaviors in the ionospheres plasma over epicenter region of the earthquakes. These registrations are correlated with the plasma parameters measured onboard DEMETER satellite and with geomagnetic indices.

  12. Optogenetic dissection of amygdala functioning

    OpenAIRE

    LaLumiere, Ryan T

    2014-01-01

    Studies of amygdala functioning have occupied a significant place in the history of understanding how the brain controls behavior and cognition. Early work on the amygdala placed this small structure as a key component in the regulation of emotion and affective behavior. Over time, our understanding of its role in brain processes has expanded, as we have uncovered amygdala influences on memory, reward behavior, and overall functioning in many other brain regions. Studies have indicated that t...

  13. Mirror therapy combined with biofeedback functional electrical stimulation for motor recovery of upper extremities after stroke: a pilot randomized controlled trial.

    Science.gov (United States)

    Kim, Jung Hee; Lee, Byoung-Hee

    2015-06-01

    The objective of this study was to evaluate the effects of mirror therapy in combination with biofeedback functional electrical stimulation (BF-FES) on motor recovery of the upper extremities after stroke. Twenty-nine patients who suffered a stroke > 6 months prior participated in this study and were randomly allocated to three groups. The BF-FES + mirror therapy and FES + mirror therapy groups practiced training for 5 × 30 min sessions over a 4-week period. The control group received a conventional physical therapy program. The following clinical tools were used to assess motor recovery of the upper extremities: electrical muscle tester, electrogoniometer, dual-inclinometer, electrodynamometer, the Box and Block Test (BBT) and Jabsen Taylor Hand Function Test (JHFT), the Functional Independence Measure, the Modified Ashworth Scale, and the Stroke Specific Quality of Life (SSQOL) assessment. The BF-FES + mirror therapy group showed significant improvement in wrist extension as revealed by the Manual Muscle Test and Range of Motion (p therapy group showed significant improvement in the BBT, JTHT, and SSQOL compared with the FES + mirror therapy group and control group (p therapy induced motor recovery and improved quality of life. These results suggest that mirror therapy, in combination with BF-FES, is feasible and effective for motor recovery of the upper extremities after stroke.

  14. Characterization of solar cells for space applications. Volume 6: Electrical characteristics of Spectrolab BSF, BSR, textured, 10 ohm-cm, 50 micron advanced OAST solar cells as a function of intensity, temperature, and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1979-01-01

    Electrical parametric data are presented on BSF, BSR, textured 10 ohm cm, 50 micron advanced OAST cells in graphical and tabular form as functions of solar illumination intensity, temperature, and 1 MeV electron fluence.

  15. Characterization of solar cells for space applications. Volume 12: Electrical characteristics of Solarex BSF, 2-ohm-cm, 50-micron solar cells (1978 pilot line) as a function of intensity, temperature, and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1980-01-01

    Electrical characteristics of Solarex back-surface-field, 2-ohm-cm, 50-micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, temperature, and irradiation.

  16. Characterization of solar cells for space applications. Volume 10: Electrical characteristics of Spectrolab BSF, textured, 10 ohm-cm, 300 micron cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1979-01-01

    Electrical characteristics of textured, back surface field, 10 ohm cm, 300 micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, and temperature.

  17. A comparison of density functional theory and coupled cluster methods for the calculation of electric dipole polarizability gradients of methane

    DEFF Research Database (Denmark)

    Paidarová, Ivana; Sauer, Stephan P. A.

    2012-01-01

    We have compared the performance of density functional theory (DFT) using five different exchange-correlation functionals with four coupled cluster theory based wave function methods in the calculation of geometrical derivatives of the polarizability tensor of methane. The polarizability gradients...... of hydrocarbons are important ingredients in the simulation of their electron energy loss spectra and reliable but cost-effective methods for obtaining the gradients need to be found. In the present work we present results of a systematic investigation on methane as a prototype molecule with special focus on DFT...... methods. The KT3, B3LYP, CAM-B3LYP, B97-2 and PBE0 DFT exchange-correlation functionals and the highly correlated wave function methods SOPPA(CCSD), CCSD-LR, CCSD and CCSD(T) were employed in combination with a series of eleven basis sets. Comparison of the DFT results with CCSD(T)/daug-cc-pVQZ reference...

  18. 脑控:基于脑-机接口的人机融合控制%Brain Control: Human-computer Integration Control Based on Brain-computer Interface

    Institute of Scientific and Technical Information of China (English)

    王行愚; 金晶; 张宇; 王蓓

    2013-01-01

    近年来,一类被称之为脑控的新型控制系统发展迅速,这是一种基于脑-机接口(Brain-computer interface,BCI)的人机融合控制系统,也是一种基于人的意念和思维的控制系统.脑控系统己被成功应用于残疾人的生活辅助、中风病人和损伤肢体的康复训练、操作员状态的实时监控、游戏娱乐和智能家居等广泛的领域.本文在简要介绍了脑控的研究背景、基本原理、系统结构和发展概况的基础上,着重对脑电信号(Electroencephalogram,EEG)模式、控制信号转换算法和应用系统研究等主要问题的研究现状,进行了较为详细的论述和分析,并探讨了进一步研究的方向和思路.最后对脑控的未来发展方向和应用前景进行了分析和展望.%Recently, a new system called brain control system has been developed rapidly. Brain control system is a human-computer integration control system based on brain-computer interface (BCI), which relies on human's ideas and thinking. Brain control system has been successfully applied in wide fields, assisting disabled patients daily life, training patients with stroke or limb injury, monitoring the status of human operator, as well as entertainment and smart house etc. In this paper, the background, basic principle, system structure and developments are firstly introduced briefly. The current research status focusing on the problems of electroencephalogram (EEG) signal pattern, control signal transfer algorithm and system application is summarized and analyzed in detail. The further research direction and thoughts are discussed. Finally, the future development of brain control is analyzed and prospects are given.

  19. State of charge estimation of Li-ion batteries in an electric vehicle based on a radial-basis-function neural network

    Institute of Scientific and Technical Information of China (English)

    Bi Jun; Shao Sai; Guan Wei; Wang Lu

    2012-01-01

    The on-line estimation of the state of charge (SOC) of the batteries is important for the reliable running of the pure electric vehicle in practice.Because a nonlinear feature exists in the batteries and the radial-basis-function neural network (RBF NN) has good characteristics to solve the nonlinear problem,a practical method for the SOC estimation of batteries based on the RBF NN with a small number of input variables and a simplified structure is proposed.Firstly,in this paper,the model of on-line SOC estimation with the RBF NN is set.Secondly,four important factors for estimating the SOC are confirmed based on the contribution analysis method,which simplifies the input variables of the RBF NN and enhances the real-time performance of estimation.Finally,the pure electric buses with LiFePO4Li-ion batteries running during the period of the 2010 Shanghai World Expo are considered as the experimental object.The performance of the SOC estimation is validated and evaluated by the battery data from the electric vehicle.

  20. Electricity generation and bivalent copper reduction as a function of operation time and cathode electrode material in microbial fuel cells

    Science.gov (United States)

    Wu, Dan; Huang, Liping; Quan, Xie; Li Puma, Gianluca

    2016-03-01

    The performance of carbon rod (CR), titanium sheet (TS), stainless steel woven mesh (SSM) and copper sheet (CS) cathode materials are investigated in microbial fuel cells (MFCs) for simultaneous electricity generation and Cu(II) reduction, in multiple batch cycle operations. After 12 cycles, the MFC with CR exhibits 55% reduction in the maximum power density and 76% increase in Cu(II) removal. In contrast, the TS and SSM cathodes at cycle 12 show maximum power densities of 1.7 (TS) and 3.4 (SSM) times, and Cu(II) removal of 1.2 (TS) and 1.3 (SSM) times higher than those observed during the first cycle. Diffusional resistance in the TS and SSM cathodes is found to appreciably decrease over time due to the copper deposition. In contrast to CR, TS and SSM, the cathode made with CS is heavily corroded in the first cycle, exhibiting significant reduction in both the maximum power density and Cu(II) removal at cycle 2, after which the performance stabilizes. These results demonstrate that the initial deposition of copper on the cathodes of MFCs is crucial for efficient and continuous Cu(II) reduction and electricity generation over prolonged time. This effect is closely associated with the nature of the cathode material. Among the materials examined, the SSM is the most effective and inexpensive cathode for practical use in MFCs.

  1. Activation and control of microlens liquid arrays on functionalized polar electric crystal substrates by electro-wetting effect and temperature

    International Nuclear Information System (INIS)

    In recent years a variety of liquid bases optical elements have been conceived, designed and fabricated even for commercial products like digital cameras o cellular phone cameras. The impressive development of microfluidic systems in conjunction with optics has led to the creation of a completely new Science field of investigation named optofludics. Optofludics, among others topics, deals with investigation and methods for realizing liquid micro-lenses. A variety of liquid micro-lenses have been designed and realized by using different configurations. We demonstrate that a lensing effect can be obtained in an open microfluidic system by using a thin layer of liquid on a polar electric crystal such as Lithium Niobate (LiNbO3). Electrowetting patterning on LiNbO3 surface is obtained by pyroelectric effect consisting in a simple but reliable electrodes-less and circuit-less configuration. The electrodes are intrinsically embedded into the substrate. The material is functionalised by means of a micro-engineering electric filed poling process. Lens array with variable focus has been demonstrated with a large number of lens elements (10x10) on micrometric scale (aperture of single lens 100 microns).

  2. Electrical percolation threshold of cementitious composites possessing self-sensing functionality incorporating different carbon-based materials

    Science.gov (United States)

    Al-Dahawi, Ali; Haroon Sarwary, Mohammad; Öztürk, Oğuzhan; Yıldırım, Gürkan; Akın, Arife; Şahmaran, Mustafa; Lachemi, Mohamed

    2016-10-01

    An experimental study was carried out to understand the electrical percolation thresholds of different carbon-based nano- and micro-scale materials in cementitious composites. Multi-walled carbon nanotubes (CNTs), graphene nanoplatelets (GNPs) and carbon black (CB) were selected as the nano-scale materials, while 6 and 12 mm long carbon fibers (CF6 and CF12) were used as the micro-scale carbon-based materials. After determining the percolation thresholds of different electrical conductive materials, mechanical properties and piezoresistive properties of specimens produced with the abovementioned conductive materials at percolation threshold were investigated under uniaxial compressive loading. Results demonstrate that regardless of initial curing age, the percolation thresholds of CNT, GNP, CB and CFs in ECC mortar specimens were around 0.55%, 2.00%, 2.00% and 1.00%, respectively. Including different carbon-based conductive materials did not harm compressive strength results; on the contrary, it improved overall values. All cementitious composites produced with carbon-based materials, with the exception of the control mixtures, exhibited piezoresistive behavior under compression, which is crucial for sensing capability. It is believed that incorporating the sensing attribute into cementitious composites will enhance benefits for sustainable civil infrastructures.

  3. Gastric potential difference measurements. The gastric mucosal integrity and function studied with a new method for measurement of the electric potential difference across the stomach wall

    DEFF Research Database (Denmark)

    Højgaard, L

    1991-01-01

    be reduced by allopurinol pretreatment, possibly due to the inhibition of oxygen-derived free radical formation. Gastric PD and pH were measured in volunteers and duodenal ulcer patients during Stroop's color word conflict test, in which mental stress causes sympathetic activation. A PD reduction and a p......H increase were found along with stress induction, thereby indicating an influence of mental stress on stomach mucosal function. It is concluded that gastric PD measurement may be useful in ulcer pathogenetic research, and a sufficient gastric mucosal blood flow is stressed as being important for the mucosal......PD--the electric potential difference across the gastric mucosa--is a variable used to describe the gastric mucosal integrity and function. A new, reliable, and easily applied method for gastric PD measurements corrected for the disturbing liquid junction potentials between gastric juice and the PD...

  4. Effectiveness of Functional Electrical Stimulation in Improving Clinical Outcomes in the Upper Arm following Stroke: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Amir K. Vafadar

    2015-01-01

    Full Text Available Background. Different therapeutic methods are being used to prevent or decrease long-term impairments of the upper arm in stroke patients. Functional electrical stimulation (FES is one of these methods, which aims to stimulate the nerves of the weakened muscles so that the resulting muscle contractions resemble those of a functional task. Objectives. The objective of this study was to review the evidence for the effect of FES on (1 shoulder subluxation, (2 pain, and (3 upper arm motor function in stroke patients, when added to conventional therapy. Methods. From the 727 retrieved articles, 10 (9 RCTs, 1 quasi-RCT were selected for final analysis and were rated based on the PEDro (Physiotherapy Evidence Database scores and the Sackett’s levels of evidence. A meta-analysis was performed for all three considered outcomes. Results. The results of the meta-analyses showed a significant difference in shoulder subluxation in experimental groups compared to control groups, only if FES was applied early after stroke. No effects were found on pain or motor function outcomes. Conclusion. FES can be used to prevent or reduce shoulder subluxation early after stroke. However, it should not be used to reduce pain or improve upper arm motor function after stroke.

  5. Clinical usefulness of brain-computer interface-controlled functional electrical stimulation for improving brain activity in children with spastic cerebral palsy: a pilot randomized controlled trial

    Science.gov (United States)

    Kim, Tae-Woo; Lee, Byoung-Hee

    2016-01-01

    [Purpose] Evaluating the effect of brain-computer interface (BCI)-based functional electrical stimulation (FES) training on brain activity in children with spastic cerebral palsy (CP) was the aim of this study. [Subjects and Methods] Subjects were randomized into a BCI-FES group (n=9) and a functional electrical stimulation (FES) control group (n=9). Subjects in the BCI-FES group received wrist and hand extension training with FES for 30 minutes per day, 5 times per week for 6 weeks under the BCI-based program. The FES group received wrist and hand extension training with FES for the same amount of time. Sensorimotor rhythms (SMR) and middle beta waves (M-beta) were measured in frontopolar regions 1 and 2 (Fp1, Fp2) to determine the effects of BCI-FES training. [Results] Significant improvements in the SMR and M-beta of Fp1 and Fp2 were seen in the BCI-FES group. In contrast, significant improvement was only seen in the SMR and M-beta of Fp2 in the control group. [Conclusion] The results of the present study suggest that BCI-controlled FES training may be helpful in improving brain activity in patients with cerebral palsy and may be applied as effectively as traditional FES training. PMID:27799677

  6. Electric charge in the stochastic electric field

    CERN Document Server

    Simonov, Yu A

    2016-01-01

    The influence of electric stochastic fields on the relativistic charged particles is investigated in the gauge invariant path integral formalism. Using the cumulant expansion one finds the exponential relaxation of the charge Green's function both for spinless and Dirac charges.

  7. Comment on "Ion distribution function in a plasma with uniform electric field" [Phys. Plasmas 19, 113703 (2012)].

    Science.gov (United States)

    Mustafaev, Alex; Sukhomlinov, Vladimir; Timofeev, Nikolay

    2016-08-01

    The comparison between experimental data of ion distribution function at the parent gas plasma obtained by the authors and results of calculations presented by Lampe et al. are considered. It is shown that the experimental and calculated angular distributions of ions in the case at least of argon differ considerably. The analysis of Lampe et al. assumptions showed that the main reasons of these discrepancies were the assumptions of ion distribution function independence on field orientation and independence of charge exchange cross-section on the relative velocity of ion and atom.

  8. Early application of percutaneous neuromuscular electric stimulation in interfering motor function of limbs and difference in temperature of axilla of patients with ischemic stroke

    Institute of Scientific and Technical Information of China (English)

    Zhenhui Jiang; Siyi Yin; Na Bi; Xiang He; Fang Qu

    2006-01-01

    BACKGROUND: Temperature of axilla could be affected due to motor dysfunction of limbs and neural changes of vessel after ischemic stroke.OBJECTIVE: To observe the effect of percutaneous neuromuscular electric stimulation (PNES) on difference in temperature of axilla and analyze the relationship between function of limbs and difference in temperature of axilla.DESIGN: Randomized grouping and controlled observation.SETTING: Department of Neurology, General Hospital of Shenyang Military Area Command of Chinese PLA.PARTICIPANTS: Sixty patients with ischemic stroke were selected from Neurological Department of General Hospital of Shenyang Military Area Command of Chinese PLA from January to June 2003. All cases were diagnosed with clinical diagnosis criteria of ischemic stroke established by the Fourth Chinese Classification of Cerebrovasular Disease and CT examination and received neuromuscular electric stimulation (NES). Patients were randomly divided into control group and treatment group with 30 in each group.METHODS: Control group: Patients received routinely neurological therapy. Treatment group: Except routine therapy, patients suffered from NES at 48 hours after hospitalization. NMT-91 NES equipment was used to stimulated injured limbs with Iow frequency once 30 minutes a day in total of 10 times a course, especially extensor muscle of upper limb and flexor muscle of lower limb. Prescription of hemiplegia was internally decided by equipment with the output frequency of 200 Hz. Intensity of electric output could cause muscle contraction.The therapy needed two or three courses. Temperature of bilateral axilla was measured every day to calculate the difference with the formula of (temperature of axilla on the injured side - temperature of axilla on the healthy side). Motor function of limbs was measured with FugI-Meyer Motor Assessment (FMA) during hospitalization and at 2 and 4 hours after hospitalization. Among 90 points, upper and lower limb function was 54

  9. APPLICATION OF TRANSCUTANEOUS ELECTRICAL STIMULATION ON LOWER LIMB ACUPOINTS AS AN IMPORTANT ADJUNCTIVE TOOL IN STROKE REHABILITATION PROGRAM & ITS EFFECTS ON SPASTICITY AND FUNCTIONAL ABILITY

    Directory of Open Access Journals (Sweden)

    Chandan Kumar

    2013-08-01

    Full Text Available Background: There is increasing evidence of neural plastic changes associated with specific training that isgoal-directed and requires special attention with practice. Sensory input by Transcutaneous electrical stimulation(TENS on acupoints and task related training (TRT induces recovery of lower limb function in patients afterstroke. There are very few studies which show the effectiveness and importance of sensory stimulation throughacupoints, therefore the purpose of the current study is to evaluate the effectiveness of TENS on acupointswhen applied with other rehabilitation program on reducing spasticity and improving lower limb function insubjects after sub-acute stroke. Materials and Methods: Thirty subjects with sub-acute stroke of either sideincluding both male and female participated in randomised clinical trial. Both group received TRT along withconventional physiotherapy program. TENS on acupoints was given in subjects of experimental group alongwith TRT and conventional program to evaluate the effectiveness of TENS. Measurement of spasticity was doneby Modified Ashworth Scale (MAS, functional ability was measured by Dynamic Gait index (DGI and Timed up& Go (TUG test. All the measurements were done before and after 5 weeks intervention. Result: A significantreduction in spasticity measured by MAS (p=0.03 and relevant improvement in functional ability measured byDGI (p=0.03 and TUG (p=0.04 were observed in experimental group after five weeks intervention.Conclusion: Present study provides an evidence to support the use of TENS on acupoints as an adjunctive toolwith task related training and other rehabilitation program.

  10. Direct electric current treatment modifies mitochondrial function and lipid body content in the A549 cancer cell line.

    Science.gov (United States)

    Holandino, Carla; Teixeira, Cesar Augusto Antunes; de Oliveira, Felipe Alves Gomes; Barbosa, Gleyce Moreno; Siqueira, Camila Monteiro; Messeder, Douglas Jardim; de Aguiar, Fernanda Silva; da Veiga, Venicio Feo; Girard-Dias, Wendell; Miranda, Kildare; Galina, Antonio; Capella, Marcia Alves Marques; Morales, Marcelo Marcos

    2016-10-01

    Electrochemical therapy (EChT) entails treatment of solid tumors with direct electric current (DC). This work evaluated the specific effects of anodic flow generated by DC on biochemical and metabolic features of the A549 human lung cancer cell line. Apoptosis was evaluated on the basis of caspase-3 activity and mitochondrial transmembrane potential dissipation. Cell morphology was analyzed using transmission electron microscopy, and lipid droplets were studied through morphometric analysis and X-ray qualitative elemental microanalysis. High-resolution respirometry was used to assess mitochondrial respiratory parameters. Results indicated A549 viability decreased in a dose-dependent manner with a prominent drop between 18 and 24h after treatment (pbodies' number, quantified by morphometrical analyses. Conversely, 24h after treatment, the cells presented a two-fold increase of residual oxygen consumption, accounting for 45.3% of basal oxygen consumption. These results show remarkable alterations promoted by anodic flow on human lung cancer cells which are possibly involved with the antitumoral effects of EChT. PMID:27243447

  11. A method for removing artefacts from continuous EEG recordings during functional electrical impedance tomography for the detection of epileptic seizures

    International Nuclear Information System (INIS)

    Electrical impedance tomography (EIT) is a portable, non-invasive medical imaging method, which could be employed to image the seizure onset in subjects undergoing assessment prior to epilepsy surgery. Each image is obtained from impedance measurements conducted with imperceptible current at tens of kHz. For concurrent imaging with video electroencephalogram (EEG), the EIT introduces a substantial artefact into the EEG due to current switching at frequencies in the EEG band. We present here a method for its removal, so that EIT and the EEG could be acquired simultaneously. A low-pass analogue filter for EEG channels (−6 dB at 48 Hz) and a high-pass filter (−3 dB at 72 Hz) for EIT channels reduced the artefact from 2–3 mV to 50–300 µV, but still left a periodic artefact at about 3 Hz. This was reduced to less than 10 µV with a software filter, which subtracted an artefact template from the EEG raw traces. The EEG was made clinically acceptable at four times its acquisition speed. This method could enable EIT to become a technique for imaging on telemetry units alongside EEG, without interfering with routine EEG reporting

  12. Direct electric current treatment modifies mitochondrial function and lipid body content in the A549 cancer cell line.

    Science.gov (United States)

    Holandino, Carla; Teixeira, Cesar Augusto Antunes; de Oliveira, Felipe Alves Gomes; Barbosa, Gleyce Moreno; Siqueira, Camila Monteiro; Messeder, Douglas Jardim; de Aguiar, Fernanda Silva; da Veiga, Venicio Feo; Girard-Dias, Wendell; Miranda, Kildare; Galina, Antonio; Capella, Marcia Alves Marques; Morales, Marcelo Marcos

    2016-10-01

    Electrochemical therapy (EChT) entails treatment of solid tumors with direct electric current (DC). This work evaluated the specific effects of anodic flow generated by DC on biochemical and metabolic features of the A549 human lung cancer cell line. Apoptosis was evaluated on the basis of caspase-3 activity and mitochondrial transmembrane potential dissipation. Cell morphology was analyzed using transmission electron microscopy, and lipid droplets were studied through morphometric analysis and X-ray qualitative elemental microanalysis. High-resolution respirometry was used to assess mitochondrial respiratory parameters. Results indicated A549 viability decreased in a dose-dependent manner with a prominent drop between 18 and 24h after treatment (p<0.001), together with a two-fold increase in caspase-3 activity. AF-treatment induced a significantly increase (p<0.01) in the cell number with disrupted mitochondrial transmembrane potential. Furthermore, treated cells demonstrated important ultrastructural mitochondria damage and a three-fold increase in the cytoplasmic lipid bodies' number, quantified by morphometrical analyses. Conversely, 24h after treatment, the cells presented a two-fold increase of residual oxygen consumption, accounting for 45.3% of basal oxygen consumption. These results show remarkable alterations promoted by anodic flow on human lung cancer cells which are possibly involved with the antitumoral effects of EChT.

  13. Differential cellular FGF-2 upregulation in the rat facial nucleus following axotomy, functional electrical stimulation and corticosterone: a possible therapeutic target to Bell's palsy

    Directory of Open Access Journals (Sweden)

    Oliveira Gabriela P

    2010-11-01

    Full Text Available Abstract Background The etiology of Bell's palsy can vary but anterograde axonal degeneration may delay spontaneous functional recovery leading the necessity of therapeutic interventions. Corticotherapy and/or complementary rehabilitation interventions have been employed. Thus the natural history of the disease reports to a neurotrophic resistance of adult facial motoneurons leading a favorable evolution however the related molecular mechanisms that might be therapeutically addressed in the resistant cases are not known. Fibroblast growth factor-2 (FGF-2 pathway signaling is a potential candidate for therapeutic development because its role on wound repair and autocrine/paracrine trophic mechanisms in the lesioned nervous system. Methods Adult rats received unilateral facial nerve crush, transection with amputation of nerve branches, or sham operation. Other group of unlesioned rats received a daily functional electrical stimulation in the levator labii superioris muscle (1 mA, 30 Hz, square wave or systemic corticosterone (10 mgkg-1. Animals were sacrificed seven days later. Results Crush and transection lesions promoted no changes in the number of neurons but increased the neurofilament in the neuronal neuropil of axotomized facial nuclei. Axotomy also elevated the number of GFAP astrocytes (143% after crush; 277% after transection and nuclear FGF-2 (57% after transection in astrocytes (confirmed by two-color immunoperoxidase in the ipsilateral facial nucleus. Image analysis reveled that a seven days functional electrical stimulation or corticosterone led to elevations of FGF-2 in the cytoplasm of neurons and in the nucleus of reactive astrocytes, respectively, without astrocytic reaction. Conclusion FGF-2 may exert paracrine/autocrine trophic actions in the facial nucleus and may be relevant as a therapeutic target to Bell's palsy.

  14. The effect of the surface functionalization and the electrolyte concentration on the electrical conductance of silica nanochannels

    OpenAIRE

    Martins, D. C.; Chu, V.; Conde, J. P.

    2013-01-01

    It is known that the conductance of nanochannels as a function of electrolyte concentration deviates from a linearly proportional relationship and approaches a value independent of the concentration as the electrolyte concentration is lowered. Most of the proposed models account for this behavior by considering a constant surface charge density and an ideal electrolyte solution. However, at low electrolyte concentrations, the ideal electrolyte approximation is no longer valid because the ions...

  15. Early rehabilitation in critical care (eRiCC): functional electrical stimulation with cycling protocol for a randomised controlled trial

    OpenAIRE

    Parry, Selina M.; Berney, Sue; Koopman, René; Bryant, Adam; El-Ansary, Doa; Puthucheary, Zudin; Hart, Nicholas; Warrillow, Stephen; Denehy, Linda

    2012-01-01

    Introduction Intensive care-acquired weakness is a common problem, leads to significant impairment in physical functioning and muscle strength, and is prevalent in individuals with sepsis. Early rehabilitation has been shown to be safe and feasible; however, commencement is often delayed due to a patient's inability to co-operate. An intervention that begins early in an intensive care unit (ICU) admission without the need for patient volition may be beneficial in attenuating muscle wasting. T...

  16. Produksi Functionally Graded Material (FGM dari Hydroxyapatite-Serat Sutra untuk Aplikasi di Bidang Biomaterial dengan Teknik Pulse Electric Current Sintering

    Directory of Open Access Journals (Sweden)

    Tjokorda Gde Tirta Nindhia

    2006-01-01

    Full Text Available This research is intended to produce functionally graded material (FGM of Hydroxyapatite (Hap-silk fibroin by pulse electric current sintering in facing the need in biomaterial application. The sample is created with 4 layers with the thickness for each layer is 0,625 mm, so that the total samples thickness become 2.5mm, with diameter 15 mm. The carbon die is used to compact the sample. The composition of lower layer is 100% silk fibroin, after that 90% silk fibroin +10% Hap, third layer was 80% silk fibroin + 20%Hap, and 70% silk fibroin +30% Hap for the upper layer. The properties of the FGM product was characterized by optical microscope and scanning electron microscope (SEM, three point bend with single-edge beam fracture toughness test (KIC. The grade of the FGM material is proven by using electron probe micro analyzer (EPMA. The value of fracture toughness is 0.45 MPa.m1/2. The sample still can support the load after maximum load is reached. Optical micrograph and SEM, and result from EPMA indicate that the Hap-silk fibroin FGM can be produce perfectly by using the method that is introduced in this research. Abstract in Bahasa Indonesia : Penelitian ini bertujuan memproduksi functionally graded material (FGM dari hydroxyapatite (Hap-serat sutra, melalui teknik pulse electric current sintering untuk memenuhi tantangan kebutuhan akan bahan jenis ini untuk digunakan dibidang biomaterial. Benda uji terdiri dari 4 lapis dengan ketebalan sama untuk tiap lapisnya sehingga tebal total menjadi 2.5 mm dengan diameter 15 mm. Komposisi lapisan paling bawah adalah 100% serat sutra, setelah itu 90% serat sutra + 10% Hap. Lapisan ketiga dengan komposisi 80% serat sutra + 20% Hap, dan 70% serat sutra + 30% Hap untuk lapisan paling atas. Perilaku produk FGM ini dikarakterisasikan dengan mikroskop optik, mikroskop electron, uji ketangguhan retak three point bend with single-edge. Gradasi (grade dari FGM dibuktikan dengan electron probe micro analyzer (EPMA

  17. [Development of a handy-type monitoring system for cardiovascular haemodynamic functions based on the volume-compensation and electrical admittance method].

    Science.gov (United States)

    Song, Yi-lin; Gao, Shu-mei; Ikarashi, Akira; Yamakoshi, Ken-ichi

    2009-03-01

    A handy-type monitoring system for cardiovascular haemodynamic functions based on the volume-compensation and electrical admittance method is developed. In this system, the inconvenient and discomfort due to cuff occlusion of the biological segment for BP measurement is improved by developing a new device using a local pressurization method, the stability for the physiological information detection is improved by developing a new detecting system, and the noise during detection using the system is greatly reduced by using a newly developed nozzle-flapper type electro-pneumatic converter. Also, for electrical admittance cardiography to estimate CO, the applicability of a two-compartment coaxial cylindrical model and the optimal position of a spot-electrode array that is used to replace the conventional band-electrode are discussed in this research. Experimental result shows that the monitoring system should satisfy non-invasive BP and CO measurement on beat by beat, and the comfort of measurement is significantly improved. PMID:19771888

  18. The Effect of NeuroMuscular Electrical Stimulation on Quadriceps Strength and Knee Function in Professional Soccer Players: Return to Sport after ACL Reconstruction

    Directory of Open Access Journals (Sweden)

    J. Taradaj

    2013-01-01

    Full Text Available The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction on the quadriceps muscle. The 80 participants (NMES = 40, control = 40 received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz three times daily (3 hours of break between treatments, 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months were applied. The results of this study show that NMES (in presented parameters in experiment is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741.

  19. The effect of neuromuscular electrical stimulation on quadriceps strength and knee function in professional soccer players: return to sport after ACL reconstruction.

    Science.gov (United States)

    Taradaj, J; Halski, T; Kucharzewski, M; Walewicz, K; Smykla, A; Ozon, M; Slupska, L; Dymarek, R; Ptaszkowski, K; Rajfur, J; Pasternok, M

    2013-01-01

    The aim of this study was to assess the clinical efficacy and safety of NMES program applied in male soccer players (after ACL reconstruction) on the quadriceps muscle. The 80 participants (NMES = 40, control = 40) received an exercise program, including three sessions weekly. The individuals in NMES group additionally received neuromuscular electrical stimulation procedures on both right and left quadriceps (biphasic symmetric rectangular pulses, frequency of impulses: 2500 Hz, and train of pulses frequency: 50 Hz) three times daily (3 hours of break between treatments), 3 days a week, for one month. The tensometry, muscle circumference, and goniometry pendulum test (follow-up after 1 and 3 months) were applied. The results of this study show that NMES (in presented parameters in experiment) is useful for strengthening the quadriceps muscle in soccer athletes. There is an evidence of the benefit of the NMES in restoring quadriceps muscle mass and strength of soccer players. In our study the neuromuscular electrical stimulation appeared to be safe for biomechanics of knee joint. The pathological changes in knee function were not observed. This trial is registered with Australian and New Zealand Clinical Trials Registry ACTRN12613001168741. PMID:24381943

  20. Functional morphology of jaw trabeculation in the lesser electric ray Narcine brasiliensis, with comments on the evolution of structural support in the Batoidea.

    Science.gov (United States)

    Dean, Mason N; Huber, Daniel R; Nance, Holly A

    2006-10-01

    The design of minimum-weight structures that retain their integrity under dynamic loading regimes has long challenged engineers. One solution to this problem found in both human and biological design is the optimization of weight and strength by hollowing a structure and replacing its inner core with supportive struts. In animals, this design is observed in sand dollar test, avian beak, and the cancellous bone of tetrapod limbs. Additionally, within the elasmobranch fishes, mineralized trabeculae (struts) have been reported in the jaws of durophagous myliobatid stingrays (Elasmobranchii: Batoidea), but were believed to be absent in basal members of the batoid clade. This study, however, presents an additional case of batoid trabeculation in the lesser electric ray, Narcine brasiliensis (Torpediniformes). The trabeculae in these species likely play different functional roles. Stingrays use their reinforced jaws to crush bivalves, yet N. brasiliensis feeds by ballistically protruding its jaws into the sediment to capture polychaetes. In N. brasiliensis, trabeculae are localized to areas likely to experience the highest load: the quadratomandibular jaw joints, hyomandibular-cranial joint, and the thinnest sections of the jaws immediately lateral to the symphyses. However, the supports perform different functions dependent on location. In regions where the jaws are loaded transversely (as in durophagous rays), "load leading" trabeculae distribute compressive forces from the cortex through the lumen of the jaws. In the parasymphyseal regions of the jaws, "truss" trabeculae form cross-braces perpendicular to the long axes of the jaws. At peak protrusion, the jaw arch is medially compressed and the jaw loaded axially such that these trabeculae are positioned to resist buckling associated with excavation forces. "Truss" trabeculae function to maintain the second moment of area in the thinnest regions of the jaws, illustrating a novel function for batoid trabeculation. Thus

  1. About the Monitoring System of Power Plant Electrical Automation Configuration Mode and Function%关于水电厂电气自动化的监控系统组态模式及功能初探

    Institute of Scientific and Technical Information of China (English)

    马艳冰

    2014-01-01

    The hydropower plant electrical automation monitoring configuration mode, the function of a hydroelectric power plant electrical automation monitoring system in order to provide reference for related work.%分析了水电厂电气自动化监控组态模式,探析了水电厂电气自动化监控系统的功能,以期能为相关工作提供借鉴。

  2. Wide-pulse electrical stimulation to an intrinsic foot muscle induces acute functional changes in forefoot-rearfoot coupling behaviour during walking.

    Science.gov (United States)

    James, D C; Chesters, T; Sumners, D P; Cook, D P; Green, D A; Mileva, K N

    2013-05-01

    Interventions for strengthening intrinsic foot muscles may be beneficial for rehabilitation from overuse injuries. In this study the acute effects of high-frequency, low-intensity wide-pulse electrical stimulation (WPS) over an intrinsic muscle on subsequent foot function during walking was assessed in healthy participants. WPS was delivered to the m. abductor hallucis (m.AH) of the non-dominant foot during relaxed standing. 3-dimensional forefoot (FF)--rearfoot (RF) coordination was quantified with a vector coding technique within separate periods of the stance phase to study WPS functional effects on foot motion. 4 types of coordinative strategies between the FF and RF were interpreted and compared PRE-to-POST-WPS for both the experimental and control feet. Bilateral electromyography (EMG) from m.AH was analysed during the intervention period for evidence of acute neuromuscular adaptation. The results showed that WPS significantly modulated FF-RF coordination during mid-stance, indicative of a more stable foot. Specifically, a statistically significant increase in FF eversion with concomitant RF inversion in the frontal plane and RF-dominated adduction in the transverse plane was observed. Subject-specific increases in post-stimulus m.AH EMG activation were observed but this was not reflected in an overall group effect. It is concluded that the structural integrity of the foot during walking is enhanced following an acute session of WPS and that this mechanical effect is most likely due to stimulation induced post-tetanic potentiation of synaptic transmission.

  3. Thermal conductivity and Kapitza resistance of cyanate ester epoxy mix and tri-functional epoxy electrical insulations at superfluid helium temperature

    CERN Document Server

    Pietrowicz, S; Jones, S; Canfer, S; Baudouy, B

    2012-01-01

    In the framework of the European Union FP7 project EuCARD, two composite insulation systems made of cyanate ester epoxy mix and tri-functional epoxy (TGPAP-DETDA) with S-glass fiber have been thermally tested as possible candidates to be the electrical insulation of 13 T Nb3Sn high field magnets under development for this program. Since it is expected to be operated in pressurized superfluid helium at 1.9 K and 1 atm, the thermal conductivity and the Kapitza resistance are the most important input parameters for the thermal design of this type of magnet and have been determined in this study. For determining these thermal properties, three sheets of each material with different thicknesses varying from 245 μm to 598 μm have been tested in steady-state condition in the temperature range of 1.6 K - 2.0 K. The thermal conductivity for the tri-functional epoxy (TGPAP-DETDA) epoxy resin insulation is found to be k=[(34.2±5.5).T-(16.4±8.2)]×10-3 Wm-1K-1 and for the cyanate ester epoxy k=[(26.8±4.8).T- (9.6±5...

  4. 临床偏瘫病人早期上肢功能性电刺激屈肌和伸肌与伸肌功能性电刺激的比较%Clinical patients with hemiplegia early upper limb functional electrical stimulationflexor and extensor compared with extensor functional electrical stimulation

    Institute of Scientific and Technical Information of China (English)

    杨一帆; 姚敬宇; 莫天才; 杨维维

    2015-01-01

    objective to patients with hemiplegia early upper limb functional electrical stimulation fiexor and extensor was compared with the extensor functional electrical stimulation.Methods acute onset in patients with hemiplegia, hemiplegic side body let in phase delay of 20 patients with hemiplegia patients at random points in the control group (n = 10) and observation group (n = 10), the control group to maintain nerve functional electrical stimulation upper limb muscle of wrist and the reach anconeus and function of routine rehabilitation training, observation group nerve functional electrical stimulation upper limbfiexor muscle of wrist and elbow fiexion with fiexor muscle tension change stimulation wrist, elbow muscle group.Before and 3 weeks after treatment with modified ashworth (Mas), concise fugl - Meyer evaluation form, out of assessment.results after treatment, no obvious difference was found between two groups of Mas, concise fugl - Meyer exercise evaluation form, out the assessment, the observation group statistically significant meaningful (P < 0.05).conclusion early fiexor functional electrical stimulation out instead of extensor muscle tension stimulation, for upper hand function in patients with hemiplegia rehabilitation and separatist movements appear faster.%目的:早期偏瘫病人上肢功能性电刺激屈肌和伸肌与伸肌功能性电刺激的比较。方法急性期发病偏瘫患者,偏瘫侧肢体任处于迟缓期的偏瘫病人20例,随机分对照组(n=10)和观察组(n=10),对照组维持神经功能性电刺激上肢伸腕肌及伸肘肌和常规康复功能训练,观察组神经功能电刺激上肢屈腕肌及屈肘肌随着屈肌张力改变刺激伸腕、伸肘肌群。治疗前及治疗3周后采用改良ashworth(Mas)、简明fugl-Meyer运动评定表、Brunnstrom进行评定。结果治疗后,两组Mas无明显差异,简明fugl-Meyer运动评定表、Brunnstrom运动评定观察组有统计学差异,有意义(P<0

  5. Characterization of solar cells for space applications. Volume 11: Electrical characteristics of 2 ohm-cm, 228 micron wraparound solar cells as a function of intensity, temperature, and irradiation. [for solar electric propulsion

    Science.gov (United States)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Weiss, R. S.

    1980-01-01

    Parametric characterization data on Spectrolab 2 by 4 cm, 2 ohm/cm, 228 micron thick wraparound cell, a candidate for the Solar Electric Propulsion Mission, are presented. These data consist of the electrical characteristics of the solar cell under a wide range of temperature and illumination intensity combinations of the type encountered in space applications.

  6. Electricity demand in Tunisia

    International Nuclear Information System (INIS)

    This paper examines the global electricity demand in Tunisia as a function of gross domestic product in constant price, the degree of urbanization, the average annual temperature, and the real electricity price per Kwh. This demand will be examined employing annual data over a period spanning almost thirty one years from 1976 to 2006. A long run relationship between the variables under consideration is determined using the Vector Autoregressive Regression. The empirical results suggest that the electricity demand in Tunisia is sensitive to its past value, any changes in gross domestic product and electricity price. The electricity price effects have a negative impact on long-run electricity consumption. However, the gross domestic product and the past value of electricity consumption have a positive effect. Moreover, the causality test reveals a unidirectional relationship between price and electricity consumption. Our empirical findings are effective to policy makers to maintain the electricity consumption in Tunisia by using the appropriate strategy. - Highlights: ► This paper examined the electricity demand in Tunisia in the long-run. ► The empirical analysis revealed that in the long-run the electricity demand is affected by changes in its past value, GDP in constant price and real electricity price. ► There is a unidirectional relationship between price and electricity consumption, that is to say, that the electricity price causes the consumption. ► Those results suggest that a pricing policy can be an effective instrument to rationalize the electricity consumption in Tunisia in the long-run.

  7. Efficacy of functional electrical stimulation on the lower limb function and walking ability of hemiplegic stroke patients%功能性电刺激对偏瘫患者下肢功能及步态的影响

    Institute of Scientific and Technical Information of China (English)

    许佳; 胡世红; 凌晴; 何嫱; 陈丽丹; 陈庆珍

    2015-01-01

    目的:观察功能性电刺激对脑卒中偏瘫患者下肢运动功能及步态的影响。方法:60例脑卒中偏瘫患者分成观察组和对照组,每组30例。对照组采用常规康复训练方法,观察组在此基础上增加佩戴步态诱发功能电刺激仪的步态训练,每次20min ,每周5次,持续8周。于治疗前后采用下肢Fugl‐Meyer运动功能评分(FMA)、功能性步行能力分级(FAC )及足印分析法对2组患者进行评定。结果:治疗8周后,2组患者下肢 FM A评分、FAC分级及患侧的平均步长、步宽及步速均较治疗前显著提高(P<0.05),且观察组更高于对照组(P<0.05)。结论:使用功能性电刺激进行步态训练后可进一步改善脑卒中偏瘫患者的下肢运动功能,提高步行能力。%Objective:To investigate the efficacy of functional electrical stimulation on the lower limb motor func‐tion and walking ability of hemiplegic stroke patients .Methods:Sixty hemiplegic stroke patients were randomly di‐vided into a treatment group and a control group (n=30 each) .Both groups were treated with routine rehabilita‐tion ,but the treatment group also undertook gait training with gait triggered functional electrical stimulation .The training was carried out 20 min every day ,5 days every week for 8 weeks .All patients were assessed with the Fugl‐Meyer lower limb assessment (FMA) ,functional ambulation category (FAC) classification and footprint analysis pretreatment and 8 weeks post‐treatment .Results:Eight weeks post‐treatment ,the FMA motor function ,FAC classification and the average values of step length ,stride width and velocity at the affected side in both two groups were significantly increased as compared with those pretreatment ,more significantly in the treatment group than in the control group (P<0 .05) .Conclusions:Gait training with functional electrical stimulation combined with routine rehabilitation training

  8. Effects of Action Observational Training Plus Brain-Computer Interface-Based Functional Electrical Stimulation on Paretic Arm Motor Recovery in Patient with Stroke: A Randomized Controlled Trial.

    Science.gov (United States)

    Kim, TaeHoon; Kim, SeongSik; Lee, ByoungHee

    2016-03-01

    The purpose of this study was to investigate whether action observational training (AOT) plus brain-computer interface-based functional electrical stimulation (BCI-FES) has a positive influence on motor recovery of paretic upper extremity in patients with stroke. This was a hospital-based, randomized controlled trial with a blinded assessor. Thirty patients with a first-time stroke were randomly allocated to one of two groups: the BCI-FES group (n = 15) and the control group (n = 15). The BCI-FES group administered to AOT plus BCI-FES on the paretic upper extremity five times per week during 4 weeks while both groups received conventional therapy. The primary outcomes were the Fugl-Meyer Assessment of the Upper Extremity, Motor Activity Log (MAL), Modified Barthel Index and range of motion of paretic arm. A blinded assessor evaluated the outcomes at baseline and 4 weeks. All baseline outcomes did not differ significantly between the two groups. After 4 weeks, the Fugl-Meyer Assessment of the Upper Extremity sub-items (total, shoulder and wrist), MAL (MAL-Activity of Use and Quality of Movement), Modified Barthel Index and wrist flexion range of motion were significantly higher in the BCI-FES group (p stroke rehabilitation. The limitations of the study are that subjects had a certain limited level of upper arm function, and the sample size was comparatively small; hence, it is recommended that future large-scale trials should consider stratified and lager populations according to upper arm function.

  9. 3D false color computed tomography for diagnosis and follow-up of permanent denervated human muscles submitted to home-based Functional Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Ugo Carraro

    2015-03-01

    Full Text Available This report outlines the use of a customized false-color 3D computed tomography (CT protocol for the imaging of the rectus femoris of spinal cord injury (SCI patients suffering from complete and permanent denervation, as characterized by complete Conus and Cauda Equina syndrome. This muscle imaging method elicits the progression of the syndrome from initial atrophy to eventual degeneration, as well as the extent to which patients' quadriceps could be recovered during four years of home-based functional electrical stimulation (h-b FES. Patients were pre-selected from several European hospitals and functionally tested by, and enrolled in the EU Commission Shared Cost Project RISE (Contract n. QLG5-CT-2001-02191 at the Department of Physical Medicine, Wilhelminenspital, Vienna, Austria. Denervated muscles were electrically stimulated using a custom-designed stimulator, large surface electrodes, and customized progressive stimulation settings. Spiral CT images and specialized computational tools were used to isolate the rectus femoris muscle and produce 3D and 2D reconstructions of the denervated muscles. The cross sections of the muscles were determined by 2D Color CT, while muscle volumes were reconstructed by 3D Color CT. Shape, volume, and density changes were measured over the entirety of each rectus femoris muscle. Changes in tissue composition within the muscle were visualized by associating different colors to specified Hounsfield unit (HU values for fat, (yellow: [-200; -10], loose connective tissue or atrophic muscle, (cyan: [-9; 40], and normal muscle, fascia and tendons included, (red: [41; 200]. The results from this analysis are presented as the average HU values within the rectus femoris muscle reconstruction, as well as the percentage of these tissues with respect to the total muscle volume. Results from this study demonstrate that h-b FES induces a compliance-dependent recovery of muscle volume and size of muscle fibers, as

  10. The Efficacy of Functional Electrical Stimulation of the Abdominal Muscles in the Treatment of Chronic Constipation in Patients with Multiple Sclerosis: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Christine Singleton

    2016-01-01

    Full Text Available Chronic constipation in patients with multiple sclerosis (MS is common and the current methods of treatment are ineffective in some patients. Anecdotal observations suggest that functional electrical stimulation (FES of the abdominal muscles may be effective in the management of constipation in these patients. Patients and Methods. In this exploratory investigation we studied the effects of FES on the whole gut transit time (WGTT and the colonic transit time (CTT. In addition, we evaluated the treatment effect on the patients’ constipation-related quality of life and on the use of laxatives and the use of manual bowel evacuation. FES was given for 30 minutes twice a day for a period of six weeks. Four female patients were studied. Results. The WGTT and CTT and constipation-related quality of life improved in all patients. The patients’ use of laxatives was reduced. No adverse effects of FES treatment were reported. Conclusion. The findings of this pilot study suggest that FES applied to the abdominal muscles may be an effective treatment modality for severe chronic constipation in patients with MS.

  11. Study on aggregation and electric properties in the micro-region of functionalized dithieno[2, 3-b: 3', 2'-d]thiophene (DTT) oligomers

    Science.gov (United States)

    Jiang, Xiaohong; Huang, Xiaowei; Zhang, Jiajia; Lu, Zhijuan; Wang, Hua; Du, Zuliang

    2016-07-01

    Three kinds of 2,5,-diphenyl-dithienol[2, 3-b: 3', 2'-d]thiophene (DP-DTT), 2,5,-distyryl-dithienol[2, 3-b: 3', 2'-d]thiophene (DEP-DTT) and 2,5,-thienyl-dithienol[2, 3-b: 3', 2'-d]thiophene (DET-DTT) micro-region structure and electronic properties were studied. Thin films of these functionalized DTT oligomers were prepared in a one-step drop-casting deposition onto highly oriented pyrolytic graphite substrates. The surface structure of these films was characterized by atomic force microscopy (AFM). Conducting probe atomic force microscope (C-AFM) and Kelvin probe force microscope (KFM) were both used to characterize the electronic transport behavior and surface potential distribution. The substituents of DTT oligomers can greatly affect their aggregation and the hopping conductance mechanism was used to explain the Au-DTTs-HOPG junctions. KFM investigation revealed that these oligomers with different substituents have different highest occupied molecular orbital energy levels. The corresponding theoretical analysis reveals similar result to KFM characterization. The I-V results indicated that the aggregates of molecules were the dominating factor to their micro-region electrical transport.

  12. Solvent primitive model of an electric double layer in slit-like pores: microscopic structure, adsorption and capacitance from a density functional approach

    Directory of Open Access Journals (Sweden)

    O. Pizio

    2014-06-01

    Full Text Available We investigate the electric double layer formed between charged walls of a slit-like pore and a solvent primitive model (SPM for electrolyte solution. The recently developed version of the weighted density functional approach for electrostatic interparticle interaction is applied to the study of the density profiles, adsorption and selectivity of adsorption of ions and solvent species. Our principal focus, however, is in the dependence of differential capacitance on the applied voltage, on the electrode and on the pore width. We discuss the properties of the model with respect to the behavior of a primitive model, i.e., in the absence of a hard-sphere solvent. We observed that the differential capacitance of the SPM on the applied electrostatic potential has the camel-like shape unless the ion fraction is high. Moreover, it is documented that the dependence of differential capacitance of the SPM on the pore width is oscillatory, which is in close similarity to the primitive model.

  13. Combined application of low-intensity pulsed ultrasound and functional electrical stimulation accelerates bone-tendon junction healing in a rabbit model.

    Science.gov (United States)

    Hu, Jianzhong; Qu, Jin; Xu, Daqi; Zhang, Tao; Qin, Ling; Lu, Hongbin

    2014-02-01

    The objective of this study was to elucidate the combined use of low-intensity pulsed ultrasound (LIPUS) and functional electrical stimulation (FES) on patella-patellar tendon (PPT) junction healing using a partial patellectomy model in rabbits. LIPUS was delivered continuously starting day 3 postoperative until week 6. FES was applied on quadriceps muscles to induce tensile force to the repaired PPT junction 5 days per week for 6 weeks since week 7 postoperatively. Forty rabbits with partial patellectomy were randomly divided into four groups: control, LIPUS alone, FES alone, and LIPUS + FES groups. At week 12, the PPT complexes were harvested for histology, radiographs, peripheral quantitative computed tomography, and biomechanical testing. There was better remodeling of newly formed bone and fibrocartilage zone in the three treatment groups compared with the control group. LIPUS and/or FES treatments significantly increased the area and bone mineral content of new bone. The failure load and ultimate strength of PPT complex were also highly improved in the three treatment groups. More new bone formed and higher tensile properties were showed in the LIPUS + FES group compared with the LIPUS or FES alone groups. Early LIPUS treatment and later FES treatment showed the additive effects of accelerating PPT junction healing.

  14. Evoked EMG versus Muscle Torque during Fatiguing Functional Electrical Stimulation-Evoked Muscle Contractions and Short-Term Recovery in Individuals with Spinal Cord Injury

    Directory of Open Access Journals (Sweden)

    Eduardo H. Estigoni

    2014-12-01

    Full Text Available This study investigated whether the relationship between muscle torque and m-waves remained constant after short recovery periods, between repeated intervals of isometric muscle contractions induced by functional electrical stimulation (FES. Eight subjects with spinal cord injury (SCI were recruited for the study. All subjects had their quadriceps muscles group stimulated during three sessions of isometric contractions separated by 5 min of recovery. The evoked-electromyographic (eEMG signals, as well as the produced torque, were synchronously acquired during the contractions and during short FES bursts applied during the recovery intervals. All analysed m-wave variables changed progressively throughout the three contractions, even though the same muscle torque was generated. The peak to peak amplitude (PtpA, and the m-wave area (Area were significantly increased, while the time between the stimulus artefact and the positive peak (PosT were substantially reduced when the muscles became fatigued. In addition, all m-wave variables recovered faster and to a greater extent than did torque after the recovery intervals. We concluded that rapid recovery intervals between FES-evoked exercise sessions can radically interfere in the use of m-waves as a proxy for torque estimation in individuals with SCI. This needs to be further investigated, in addition to seeking a better understanding of the mechanisms of muscle fatigue and recovery.

  15. Inflammation-mediating cytokine response to acute handcycling exercise with/without functional electrical stimulation-evoked lower-limb cycling

    Directory of Open Access Journals (Sweden)

    Thomas A. W. Paulson, MSc

    2014-07-01

    Full Text Available This feasibility study compared the plasma inflammation-mediating cytokine response to an acute bout of handcycling (HC with and without the addition of functional electrical stimulation (FES-evoked lower-limb cycling. On two separate occasions, five recreationally active, community-based participants with motor complete paraplegia (thoracic 5–7 performed 30 min HC and hybrid exercise (HYB at a fixed power output. Venous blood samples were collected at rest, immediately postexercise, 1 h postexercise (post+1 and 2 h postexercise (post+2. Plasma interleukin (IL-6, IL-10, IL-1 receptor antagonist (IL-1ra, adrenaline, and cortisol concentrations were determined via enzyme-linked immunoassay. Plasma IL-6 concentrations were significantly (p 0.05 increase in IL-6 was observed at post+1 in HC, with concentrations significantly higher in HYB at post+2 (p < 0.02. Plasma IL-1ra was unaffected in both trials. Although not reaching statistical significance (p = 0.15, a ~1-fold increase in IL-10 concentration was seen in HYB at post+2. In contrast, increases in adrenaline (p < 0.04 and cortisol (p = 0.08 were observed immediately postexercise in HC and HYB. Initial findings suggest paralyzed skeletal muscle releases IL-6 in response to FES-evoked contractions. HYB may provide a greater anti-inflammatory potential in individuals with a thoracic spinal cord injury compared with HC alone.

  16. Invited commentary on comparison of robotics, functional electrical stimulation, and motor learning methods for treatment of persistent upper extremity dysfunction after stroke: a randomized controlled trial.

    Science.gov (United States)

    Kwakkel, Gert; van Wegen, Erwin E; Meskers, Carel M

    2015-06-01

    In this issue of Archives of Physical Medicine and Rehabilitation, Jessica McCabe and colleagues report findings from their methodologically sound, dose-matched clinical trial in 39 patients beyond 6 months poststroke. In this phase II trial, the effects of 60 treatment sessions, each involving 3.5 hours of intensive practice plus either 1.5 hours of functional electrical stimulation (FES) or a shoulder-arm robotic therapy, were compared with 5 hours of intensive daily practice alone. Although no significant between-group differences were found on the primary outcome measure of Arm Motor Ability Test and the secondary outcome measure of Fugl-Meyer Arm motor score, 10% to 15% within-group therapeutic gains were on the Arm Motor Ability Test and Fugl-Meyer Arm. These gains are clinically meaningful for patients with stroke. However, the underlying mechanisms that drive these improvements remain poorly understood. The approximately $1000 cost reduction per patient calculated for the use of motor learning (ML) methods alone or combined with FES, compared with the combination of ML and shoulder-arm robotics, further emphasizes the need for cost considerations when making clinical decisions about selecting the most appropriate therapy for the upper paretic limb in patients with chronic stroke.

  17. Nanosecond pulse electric field activation of platelet-rich plasma reduces myocardial infarct size and improves left ventricular mechanical function in the rabbit heart.

    Science.gov (United States)

    Hargrave, Barbara; Li, Francis

    2012-12-01

    In the current study, we used the novel, nonchemical method of nanosecond pulsed electric fields (nsPEF) to investigate the efficiency of a protocol involving the in vivo treatment of the ischemic and reperfused heart and heart cells in culture with platelet-rich plasma (PRP). Associated with the restoration of blood flow to the ischemic tissue is a phenomenon referred to as "ischemic reperfusion injury." Clinically a type of reperfusion injury occurs during coronary bypass surgery once blood perfusion to the heart is restarted. Although the restoration of oxygen to ischemic myocardial cells is critical for tissue survival, reperfusion causes myocardial oxidative stress, attributable in part to the increased production of reactive oxygen species (ROS). Enhanced ROS production is associated with mitochondrial damage. Adult female New Zealand white rabbits were anesthetized and a left thoracotomy performed to expose the heart. The distal segment of the left anterior descending coronary artery was occluded for 15 minutes and then released so reperfusion of the tissue could occur. PRP (.21 mg/heart) or saline was injected into the ischemic area of the myocardium. Mechanical function of the left ventricle was analyzed using a Millar catheter attached to a Micro-Med Analysis System. H9c2 cells in culture were treated with 1 mL of nsPEF activated PRP (1.05 mg/flask) for 24 hours before analysis for ROS production or mitochondrial depolarization damage). The left ventricle contracted and relaxed faster and infarct size was reduced in hearts treated with PRP compared with saline. ROS production and mitochondrial depolarization were reduced in H9c2 cells treated with PRP and stimulated with hydrogen peroxide. These results provide evidence that nsPEFs can successfully be used to prepare PRP and that the PRP is functional in heart protection possibly by reducing ROS generation and stabilizing the mitochondria of the ischemic/reperfused heart.

  18. Real time stagger of electric network advanced analysis functions of a modern control center; Escalonamento em tempo real das funcoes avancadas de analise de rede eletrica de um moderno centro de controle

    Energy Technology Data Exchange (ETDEWEB)

    Zagari, Eduardo Nicola Ferraz

    1996-02-01

    This work presents two models for implementation of staggers for network analysis functions in real time for a control center. The methodology is described. Tests were performed in a electric power system of Campinas region, Sao Paulo sate - Southeast Brazil. Results are presented.

  19. 功能性电刺激对痉挛型双瘫型脑瘫患儿运动功能的影响%Effects of functional electrical stimulation on motor function in children with spastic diplegia

    Institute of Scientific and Technical Information of China (English)

    谢闽达; 许晶莉

    2013-01-01

    目的:探讨功能性电刺激对痉挛型双瘫型脑瘫患儿运动功能的影响。方法:选择痉挛型双瘫型脑瘫患儿共60例,将全部患儿随机分为治疗组与对照组,每组各30例,对照组采用常规综合康复治疗,治疗组在此基础上增加功能性电刺激治疗。刺激部位:胫骨前肌、股四头肌、臀大肌。2组患儿均持续治疗1个疗程,在康复治疗前及治疗后均进行粗大运动功能测试量表( gross motor function measure scale ,GMFM)检测徒手肌力法( manual muscle testing ,MMT)测试。结果:康复治疗后,治疗组肌力提高总有效率为83.33%。对照组肌力提高总有效率为66.67%,2组肌力比较有显著性差异(P<0.05);治疗后,2组GMFM总分均显著高于治疗前(P<0.01),治疗组GMFM总分显著高于对照组(P<0.05)。结论:功能性电刺激有助于改善脑瘫患儿的运动功能。%Objective: To investigate the effects of functional electrical stimulation ( FES) on motor function in children with spastic diplegia.Methods:60 children with spastic diplegia were randomly divided into treatment group ( n=30 ) and control group(n=30).All patients received combined therapy,while the treatment group was added with FES.The surface electrodes were applied on the anterior tibialis,quadriceps and gluteus maximus.The treatment was performed for 3 months and the meas-urements of gross motor function measure scale( GMFM) and manual muscle testing( MMT) were made before and after the reha-bilitation training for both groups.Results: The total effective rate of strength improvements in the treatment group was 83. 33%,which was 66.67% in the control group.There was significant difference between the two groups(P <0.05).It was found that the total of GMFM increased significantly after 3 months in both groups(P<0.01) and it was significantly higher in the treatment group than in the control group ( P<0 .05

  20. Electric Power

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ China Council for the Promotion of International Trade Electric Power Industry Office (CCPIT Electric Power), one of the pro-fessional industrial branches of China Council for the Promotion of International Trade (CCPIT), was established in 2006.

  1. A comparative investigation of an AB- and AA-stacked bilayer graphene sheet under an applied electric field:A density functional theory study

    Institute of Scientific and Technical Information of China (English)

    Wang Tao; Guo Qing; Liu Yan; Sheng Kuang

    2012-01-01

    An AB- and AA-stacked bilayer graphene sheet (BLG) under an electric field is investigated by ab initio calculation.The interlayer distance between the two layers,band structures,and atomic charges of the system are investigated in the presence of different electric fields normal to the BLG.The AB-stacked BLG is able to tune the bandgap into 0.234 eV with the increase of the external electronic field to 1 V/nm,however,the AA-stacked BLG is not sensitive to the external electric field.In both the cases,the spacing between the BLG slightly change in terms of the electric field.The charges in the AB-stacked BLG are increased with the increase of the electric field,which is considered to be the reason that causes the bandgap opening in the AB-stacked BLG.

  2. Bipedal gait experiment for functional electrical stimulation%服务于功能性电刺激的双足步态实验

    Institute of Scientific and Technical Information of China (English)

    王颖; 张定国

    2012-01-01

    BACKGROUND: Functional electrical stimulation (FES) uses electrical pulse of low level to stimulate the peripheral nerve of muscles in order to restore the motor functions, and it has already achieved clinical success in area of paraplegic walking. However, the patterns of FES are inflexible, unstable and hard to operate for the end-users at present.OBJECTIVE: To study the synergistic action of the muscles involved in walking movements for simplifying the design of FES control patterns based on gait analysis and to make the subjects perform expected involuntary walking movements using FES.METHODS: According to the characteristics of bipedal walking, a method of gait research was proposed based on measurement and analysis of joint angle and electromyography signal. It served for FES system design, which generated the desired stimulation patterns for muscle groups of lower limbs, and realized the corresponding collaborative activation of the muscle groups.RESULTS AND CONCLUSION: Satisfactory involuntary walking of a healthy subject without self-control was realized using the FES method proposed. The results from the experiment had verified the feasibility of FES in lower limb rehabilitation. It sheds light on more complex FES control methods, and provides experimental support for clinical study on paralyzed patients in future.%背景:功能性电刺激利用低频弱电流脉冲刺激失去神经控制的肌肉已经在截瘫行走的临床应用中取得了小范围成功,但现有的电刺激模式存在不灵活、不易操作、且稳定性不高的缺点.目的:基于步态分析方法,研究涉及到步行动作的各肌肉群的协同动作关系,将肌肉电刺激模式简化为无需患者操作的规律性控制策略,并验证该策略在功能性电刺激实验中的有效性.方法:针对双足步行的特点,提出一种基于关节角变化趋势及肌电信号强度变化的步态研究方法,旨在服务于功能性电刺激的设计,为下肢肌肉

  3. Electrical steering of vehicles

    DEFF Research Database (Denmark)

    Blanke, Mogens; Thomsen, Jesper Sandberg

    2006-01-01

    solutions and still meet strict requirements to functional safety. The paper applies graph-based analysis of functional system structure to find a novel fault-tolerant architecture for an electrical steering where a dedicated AC-motor design and cheap voltage measurements ensure ability to detect all...

  4. European transition to a low carbon electricity system using a mix of variable renewable energies: carbon saving trajectories as functions of production and storage capacity.

    Science.gov (United States)

    Francois, Baptiste; Creutin, Jean-Dominique

    2016-04-01

    Today, most of the produced energy is generated from fossil energy sources (i.e. coal, petroleum). As a result, the energy sector is still the main source of greenhouse gas in the atmosphere. For limiting greenhouse gas emission, a transition from fossil to renewable energy is required, increasing gradually the fraction energy coming from variable renewable energy (i.e. solar power, wind power and run-of-the river hydropower, hereafter denoted as VRE). VRE penetration, i.e. the percentage of demand satisfied by variable renewables assuming no storage capacity, is hampered by their variable and un-controllable features. Many studies show that combining different VRE over space smoothes their variability and increases their global penetration by a better match of demand fluctuations. When the demand is not fully supplied by the VRE generation, backup generation is required from stored energy (mostly from dams) or fossil sources, the latter being associated with high greenhouse gas emission. Thus the VRE penetration is a direct indicator of carbon savings and basically depends on the VRE installed capacity, its mix features, and on the installed storage capacity. In this study we analyze the European transition to a low carbon electricity system. Over a selection of representative regions we analyze carbon saving trajectories as functions of VRE production and storage capacities for different scenarios mixing one to three VRE with non-renewables. We show substantial differences between trajectories when the mix of sources is far from the local optimums, when the storage capacity evolves. We bring new elements of reflection about the effect of transport grid features from local independent systems to a European "copper plate". This work is part of the FP7 project COMPLEX (Knowledge based climate mitigation systems for a low carbon economy; Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/).

  5. The effects of anodal transcranial direct current stimulation and patterned electrical stimulation on spinal inhibitory interneurons and motor function in patients with spinal cord injury.

    Science.gov (United States)

    Yamaguchi, Tomofumi; Fujiwara, Toshiyuki; Tsai, Yun-An; Tang, Shuen-Chang; Kawakami, Michiyuki; Mizuno, Katsuhiro; Kodama, Mitsuhiko; Masakado, Yoshihisa; Liu, Meigen

    2016-06-01

    Supraspinal excitability and sensory input may play an important role for the modulation of spinal inhibitory interneurons and functional recovery among patients with incomplete spinal cord injury (SCI). Here, we investigated the effects of anodal transcranial direct current stimulation (tDCS) combined with patterned electrical stimulation (PES) on spinal inhibitory interneurons in patients with chronic incomplete SCI and in healthy individuals. Eleven patients with incomplete SCI and ten healthy adults participated in a single-masked, sham-controlled crossover study. PES involved stimulating the common peroneal nerve with a train of ten 100 Hz pulses every 2 s for 20 min. Anodal tDCS (1 mA) was simultaneously applied to the primary motor cortex that controls the tibialis anterior muscle. We measured reciprocal inhibition and presynaptic inhibition of a soleus H-reflex by stimulating the common peroneal nerve prior to tibial nerve stimulation, which elicits the H-reflex. The inhibition was assessed before, immediately after, 10 min after and 20 min after the stimulation. Compared with baseline, simultaneous application of anodal tDCS with PES significantly increased changes in disynaptic reciprocal inhibition and long-latency presynaptic inhibition in both healthy and SCI groups for at least 20 min after the stimulation (all, p < 0.001). In patients with incomplete SCI, anodal tDCS with PES significantly increased the number of ankle movements in 10 s at 20 min after the stimulation (p = 0.004). In conclusion, anodal tDCS combined with PES could induce spinal plasticity and improve ankle movement in patients with incomplete SCI. PMID:26790423

  6. Use of anisotropic modelling in electrical impedance tomography: description of method and preliminary assessment of utility in imaging brain function in the adult human head.

    Science.gov (United States)

    Abascal, Juan-Felipe P J; Arridge, Simon R; Atkinson, David; Horesh, Raya; Fabrizi, Lorenzo; De Lucia, Marzia; Horesh, Lior; Bayford, Richard H; Holder, David S

    2008-11-01

    Electrical Impedance Tomography (EIT) is an imaging method which enables a volume conductivity map of a subject to be produced from multiple impedance measurements. It has the potential to become a portable non-invasive imaging technique of particular use in imaging brain function. Accurate numerical forward models may be used to improve image reconstruction but, until now, have employed an assumption of isotropic tissue conductivity. This may be expected to introduce inaccuracy, as body tissues, especially those such as white matter and the skull in head imaging, are highly anisotropic. The purpose of this study was, for the first time, to develop a method for incorporating anisotropy in a forward numerical model for EIT of the head and assess the resulting improvement in image quality in the case of linear reconstruction of one example of the human head. A realistic Finite Element Model (FEM) of an adult human head with segments for the scalp, skull, CSF, and brain was produced from a structural MRI. Anisotropy of the brain was estimated from a diffusion tensor-MRI of the same subject and anisotropy of the skull was approximated from the structural information. A method for incorporation of anisotropy in the forward model and its use in image reconstruction was produced. The improvement in reconstructed image quality was assessed in computer simulation by producing forward data, and then linear reconstruction using a sensitivity matrix approach. The mean boundary data difference between anisotropic and isotropic forward models for a reference conductivity was 50%. Use of the correct anisotropic FEM in image reconstruction, as opposed to an isotropic one, corrected an error of 24 mm in imaging a 10% conductivity decrease located in the hippocampus, improved localisation for conductivity changes deep in the brain and due to epilepsy by 4-17 mm, and, overall, led to a substantial improvement on image quality. This suggests that incorporation of anisotropy in

  7. Home-based Functional Electrical Stimulation for long-term denervated human muscle: History, basics, results and perspectives of the Vienna Rehabilitation Strategy

    Directory of Open Access Journals (Sweden)

    Helmut Kern

    2014-03-01

    Full Text Available We will here discuss the following points related to Home-based Functional Electrical Stimulation (h-b FES as treatment for patients with permanently denervated muscles in their legs: 1. Upper (UMN and lower motor neuron (LMN damage to the lower spinal cord; 2. Muscle atrophy/hypertrophy versus processes of degeneration, regeneration, and recovery; 3. Recovery of twitch- and tetanic-contractility by h-b FES; 4. Clinical effects of h-b FES using the protocol of the “Vienna School”; 5. Limitations and perspectives. Arguments in favor of using the Vienna protocol include: 1. Increased muscle size in both legs; 2. Improved tetanic force production after 3-5 months of percutaneous stimulation using long stimulus pulses (> 100 msec of high amplitude (> 80 mAmp, tolerated only in patients with no pain sensibility; 3. Histological and electron microscopic evidence that two years of h-b FES return muscle fibers to a state typical of two weeks denervated muscles with respect to atrophy, disrupted myofibrillar structure, and disorganized Excitation-Contraction Coupling (E-CC structures; 4. The excitability never recovers to that typical of normal or reinnervated muscles where pulses less than 1 msec in duration and 25 mAmp in intensity excite axons and thereby muscle fibres. It is important to motivate these patients for chronic stimulation throughout life, preferably standing up against the load of the body weight rather than sitting. Only younger and low weight patients can expect to be able to stand-up and do some steps more or less independently. Some patients like to maintain the h-b FES training for decades. Limitations of the procedure are obvious, in part related to the use of multiple, large surface electrodes and the amount of time patients are willing to use for such muscle training.

  8. Effects of brain-derived neurotrophic factor (BDNF) and electrical stimulation on survival and function of cochlear spiral ganglion neurons in deafened, developing cats.

    Science.gov (United States)

    Leake, Patricia A; Stakhovskaya, Olga; Hetherington, Alexander; Rebscher, Stephen J; Bonham, Ben

    2013-04-01

    Both neurotrophic support and neural activity are required for normal postnatal development and survival of cochlear spiral ganglion (SG) neurons. Previous studies in neonatally deafened cats demonstrated that electrical stimulation (ES) from a cochlear implant can promote improved SG survival but does not completely prevent progressive neural degeneration. Neurotrophic agents combined with an implant may further improve neural survival. Short-term studies in rodents have shown that brain-derived neurotrophic factor (BDNF) promotes SG survival after deafness and may be additive to trophic effects of stimulation. Our recent study in neonatally deafened cats provided the first evidence of BDNF neurotrophic effects in the developing auditory system over a prolonged duration Leake et al. (J Comp Neurol 519:1526-1545, 2011). Ten weeks of intracochlear BDNF infusion starting at 4 weeks of age elicited significant improvement in SG survival and larger soma size compared to contralateral. In the present study, the same deafening and BDNF infusion procedures were combined with several months of ES from an implant. After combined BDNF + ES, a highly significant increase in SG numerical density (>50 % improvement re: contralateral) was observed, which was significantly greater than the neurotrophic effect seen with ES-only over comparable durations. Combined BDNF + ES also resulted in a higher density of myelinated radial nerve fibers within the osseous spiral lamina. However, substantial ectopic and disorganized sprouting of these fibers into the scala tympani also occurred, which may be deleterious to implant function. EABR thresholds improved (re: initial thresholds at time of implantation) on the chronically stimulated channels of the implant. Terminal electrophysiological studies recording in the inferior colliculus (IC) revealed that the basic cochleotopic organization was intact in the midbrain in all studied groups. In deafened controls or after ES-only, lower IC

  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. 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

  11. Electric turbocompound control system

    Energy Technology Data Exchange (ETDEWEB)

    Algrain, Marcelo C. (Dunlap, IL)

    2007-02-13

    Turbocompound systems can be used to affect engine operation using the energy in exhaust gas that is driving the available turbocharger. A first electrical device acts as a generator in response to turbocharger rotation. A second electrical device acts as a motor to put mechanical power into the engine, typically at the crankshaft. Apparatus, systems, steps, and methods are described to control the generator and motor operations to control the amount of power being recovered. This can control engine operation closer to desirable parameters for given engine-related operating conditions compared to actual. The electrical devices can also operate in "reverse," going between motor and generator functions. This permits the electrical device associated with the crankshaft to drive the electrical device associated with the turbocharger as a motor, overcoming deficient engine operating conditions such as associated with turbocharger lag.

  12. Functional electrical stimulation as a safe and effective treatment for equine epaxial muscle spasms: Clinical evaluations and histochemical morphometry of mitochondria in muscle biopsies

    Directory of Open Access Journals (Sweden)

    Barbara Ravara

    2015-03-01

    Full Text Available Functional Electrical Stimulation (FES has been used extensively over several decades to reverse muscle atrophy during rehabilitation for spinal cord injury patients. The benefits of the technology are being expanded into other areas, and FES has been recently utilized for injury rehabilitation and performance enhancement in horses. Six retired horses (age from 10 to 17 yrs that had been previously used mainly for dressage riding were selected for this study. Clinical evaluation found epaxial muscle spasms in all horses with minimal to no pelvic extension when manually palpated. FES treatments were performed on the sacral/lumbar region 3 times per week for a period of 8 weeks, obtaining a total of 22 treatments per horse. The Modified Ashworth Scale for grading muscle spasms found a one grade improvement after approximately four FES treatments, indicating improved functional movement of the sacral/lumbar region, supporting the evidence by clinical palpations that a reduction in epaxial muscle spasms occurred. Skeletal muscle biopsies Pre and Post FES treatments were obtained from the longissimus lumborum muscle. Cryosections were stained with a Hemotoxylin-Eosin (H-E, and nicotinamide adenine dinucleotide tetrazolium reductase reaction (NADH-TR. The eventual size change of the muscle fibers were evaluated by morphometry in the H-E and NADH-TR stained cryosections, while in the NADH-TR slides the histochemical density and distribution of mitochondria were also determined. The main results of the morphometric analyses were: 1 As expected for the type of FES treatment used in this study, only a couple of horses showed significant increases in mean muscle fiber size when Pre- vs Post-FES biopsies were compared; 2 In the older horses, there were sparse (or many in one horse very atrophic and angulated muscle fibers in both Pre- and Post-FES samples, whose attributes and distribution suggests that they were denervated due to a distal neuropathy; 3 The

  13. 电刺激对脑梗死大鼠运动功能和Rho激酶表达的影响%Effects of electric stimulation on motor function and the expression of Rho kinase following cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    陈涛; 张秀清; 唐吉友

    2010-01-01

    目的 探讨单侧与双侧电刺激对脑梗死大鼠肢体运动功能和Rho激酶表达的影响.方法 采用线栓法制作Sprague-Dawley大鼠大脑中动脉永久性闭塞模型,将造模成功且存活的脑梗死大鼠分为假手术组、对照组、单侧电刺激组、双侧电刺激组(各36只),假手术组、对照组自然恢复,单、双侧电刺激组接受电刺激治疗.利用平衡木试验(BWT)观察造模后第3天、第7天、第14天和第21天各组大鼠运动功能恢复情况,同时采用免疫组化染色法检测脑梗死灶周边区Rho激酶的表达水平,采用2,3,5-氯化三苯基四氮唑(TTC)染色法检测脑梗死灶体积的变化.结果 第7,14,21天,电刺激组大鼠BWT评分明显高于对照组(P0.05),第21天脑梗死灶体积显著缩小(P0.05).结论 早期电刺激能够促进脑梗死大鼠运动功能的恢复,并且促进脑梗死灶体积缩小,双侧电刺激疗效优于单侧电刺激,其机制可能与下调脑梗死灶周边区Rho激酶的表达有关.%Objective To investigate the effects of electric stimulation on motor function and expression of Rho kinase following cerebral infarction in rats. Methods Acute cerebral infarction was modeled in adult male Sprague-Dawley ( SD) rats using the permanent middle cerebral artery occlusion ( PMCAO) technique. The rats were randomly divided into sham operation, control, unilateral electric stimulation and bilateral electric stimulation groups ( each group had 36 rats). Electric stimulation was applied to the paralyzed ( unilateral or bilateral) limbs in the last two groups. Motor function recovery and the expression of Rho kinase were examined using a beam walking test ( BWT) and immunohistochemistry respectively at the 3rd, 7th, 14th and 21st day after stimulation. In addition, the cerebral infarction volume was also determined by 2, 3, 5-triphenyl tetrazolium chloride (TTC) staining at different time points. Results Motor function improved significantly in the

  14. Transcranial Electric Field Stimulation

    OpenAIRE

    Arfaee, Arash

    2015-01-01

    Nervous stimulation with electric methods not only has a long history in the treatment of many conditions but also in the last two decades has been used increasingly as a powerful functional brain mapping tool alongside other imaging techniques. This technology has been used to record the stimulation-evoked activity of the stimulated location. This research describes work surrounding a novel technique for brain and nervous stimulation using the electric field as the medium; particularly tra...

  15. Neuromuscular electrical stimulation and dietary interventions to reduce oxidative stress in a secondary progressive multiple sclerosis patient leads to marked gains in function: a case report

    OpenAIRE

    Reese, David; Shivapour, Ezzatolah T; Wahls, Terry L.; Dudley-Javoroski, Shauna D; Shields, Richard

    2009-01-01

    Neuromuscular electrical stimulation has been used to aid musculoskeletal recovery. Excessive oxidative stress and excitoxicity are implicated in secondary progressive multiple sclerosis. A 52-year-old white female with SPMS had been scooter- and cane-dependent for 4 years. She requested and received a trial of neuromuscular electrical stimulation. Two months after initiating NMES the patient adopted several nutritional interventions to lower oxidative stress and excito-toxicity. During the f...

  16. Effectiveness of bisphosphonate analogues and functional electrical stimulation on attenuating post-injury osteoporosis in spinal cord injury patients- a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Ke-Vin Chang

    Full Text Available BACKGROUND: Various pharmacologic and non-pharmacologic approaches have been applied to reduce sublesional bone loss after spinal cord injury (SCI, and the results are inconsistent across the studies. The objective of this meta-analysis was to investigate whether the two most-studied interventions, bisphosphonate analogues and functional electrical stimulation (FES, could effectively decrease bone mineral density (BMD attenuation and/or restore lost BMD in the SCI population. METHODS: Randomized controlled trials, quasi-experimental studies, and prospective follow-up studies employing bisphosphonates or FES to treat post-SCI osteoporosis were identified in PubMed and Scopus. The primary outcome was the percentage of BMD change from baseline measured by dual-energy X-ray absorptiometry (DEXA or computed tomography (CT. Data were extracted from four points: the 3rd, 6th, 12th, and 18th month after intervention. RESULTS: A total of 19 studies were included in the analysis and involved 364 patients and 14 healthy individuals. Acute SCI participants treated with bisphosphonate therapy demonstrated a trend toward less bone loss than participants who received placebos or usual care. A significant difference in BMD decline was noted between both groups at the 3rd and 12th month post-medication. The subgroup analysis failed to show the superiority of intravenous bisphosphonate over oral administration. Regarding FES training, chronic SCI patients had 5.96% (95% CI, 2.08% to 9.84%, 7.21% (95%CI, 1.79% to 12.62%, and 9.56% (95% CI, 2.86% to 16.26% increases in BMD at the 3rd, 6th, and 12th months post-treatment, respectively. The studies employing FES ≥ 5 days per week were likely to have better effectiveness than studies using FES ≤ 3 days per week. CONCLUSIONS: Our meta-analysis indicated bisphosphonate administration early following SCI effectively attenuated sublesional bone loss. FES intervention for chronic SCI patients could significantly

  17. 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

  18. Electrical stator

    Science.gov (United States)

    Fanning, Alan W.; Olich, Eugene E.

    1994-01-01

    An electrical stator of an electromagnetic pump includes first and second spaced apart coils each having input and output terminals for carrying electrical current. An elongate electrical connector extends between the first and second coils and has first and second opposite ends. The connector ends include respective slots receiving therein respective ones of the coil terminals to define respective first and second joints. Each of the joints includes a braze filler fixedly joining the connector ends to the respective coil terminals for carrying electrical current therethrough.

  19. The Newnes guide to home electrics

    CERN Document Server

    Burdett, Geoffrey

    2013-01-01

    Home Electrics, Second Edition provides a do-it-yourself (DIY) guide to residential electric systems. The book is comprised of 15 chapters that cover the different aspects of home electrics. The topics covered in the text include electrical installation, rewiring, power circuits, electrical hardware, electrical repairs, tools, and safety. The book also discusses a specific area or function of home electronics, such as lighting system, lamps, electric cookers, and outdoor electrical extension. The book will be of great use to individuals interested in learning how to conduct proper home electri

  20. Habitual functional electrical stimulation therapy improves gait kinematics and walking performance, but not patient-reported functional outcomes, of people with multiple sclerosis who present with foot-drop.

    Directory of Open Access Journals (Sweden)

    Marietta L van der Linden

    Full Text Available BACKGROUND: People with Multiple Sclerosis (pwMS often experience a disturbed gait function such as foot-drop. The objective of this pilot study was to investigate the medium term effects of using Functional Electrical Stimulation (FES to treat foot-drop over a period 12 weeks on gait and patient reported outcomes of pwMS. METHODS AND FINDINGS: Nine pwMS aged 35 to 64 (2 males, 7 females were assessed on four occasions; four weeks before baseline, at baseline and after six weeks and twelve weeks of FES use. Joint kinematics and performance on the 10 meter and 2 minute walk tests (10WT, 2 minWT were assessed with and without FES. Participants also completed the MS walking Scale (MSWS, MS impact scale (MSIS29, Fatigue Severity Score (FSS and wore an activity monitor for seven days after each assessment. Compared to unassisted walking, FES resulted in statistically significant improvements in peak dorsiflexion in swing (p = 0.006, 10MWT (p = 0.006 and 2 minWT (p = 0.002. Effect sizes for the training effect, defined as the change from unassisted walking at baseline to that at 12 weeks, indicated improved ankle angle at initial contact (2.6°, 95% CI -1° to 4°, d = 0.78, and a decrease in perceived exertion over the 2 min walking tests (-1.2 points, 95% CI -5.7 to 3.4, d = -0.86. Five participants exceeded the Minimally Detectable Change (MDC for a training effect on the 10mWT, but only two did so for the 2 minWT. No effects of the use of FES for 12 weeks were found for MSWS, MSIS29, FSS or step count. CONCLUSION: Although FES to treat foot-drop appears to offer the potential for a medium term training effect on ankle kinematics and walking speed, this was not reflected in the patient reported outcomes. This observed lack of relationship between objective walking performance and patient reported outcomes warrants further investigation. TRIAL REGISTRATION: ClinicalTrials.gov NCT01977287.

  1. Electric behavior of functional glasses based on TeO{sub 2}; Comportamiento electrico de vidrios funcionales con base en TeO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Terny, S.; Rubia, M. a. de la; Barolin, S.; Alonso, R. E.; Frutos, J. de; Frechero, M. A.

    2014-02-01

    In this paper we study the structural and electrical behavior of glass-ceramic material of general formula: xMgO (1-x) (0.5V{sub 2}O{sub 5}.0.5MoO{sub 3})2TeO{sub 2} (0{<=} x{<=}0.9) through measurements of density, molar volume, oxygen packing density (OPD), differential scanning calorimetry (DSC) and Raman spectroscopy: electric behavior was studied by impedance spectroscopy. We found that magnesium cation induces the growth of slightly crystallized areas inside the material. Those nanocrystallizations were detected to a greater extent by atomic force microscopy (AFM) and in lesser extent by X-ray diffraction (XRD). Regarding the electrical measurements, it can be established that magnesium cation does not act as good ionic conductor in this material. (Author)

  2. Electric machine

    Science.gov (United States)

    El-Refaie, Ayman Mohamed Fawzi; Reddy, Patel Bhageerath

    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.

  3. Towards the hybrid organic semiconductor fet (hosfet) : electrical and electrochemical characterization of functionalized and unfunctionalized, covalently bound organic monolayers on silicon surfaces

    NARCIS (Netherlands)

    Faber, Erik Jouwert

    2006-01-01

    Since their introduction in 1993 the class of covalently bound organic monolayers on oxide free silicon surfaces have found their way to multiple application fields such as passivation layers in solar cells, masking layers in lithographic processing, insulating films in hybrid moleculesilicon electr

  4. Annotation: What Electrical Brain Activity Tells Us about Brain Function that Other Techniques Cannot Tell Us--A Child Psychiatric Perspective

    Science.gov (United States)

    Banaschewski, Tobias; Brandeis, Daniel

    2007-01-01

    Background: Monitoring brain processes in real time requires genuine subsecond resolution to follow the typical timing and frequency of neural events. Non-invasive recordings of electric (EEG/ERP) and magnetic (MEG) fields provide this time resolution. They directly measure neural activations associated with a wide variety of brain states and…

  5. Bond length and electric current oscillation of long linear carbon chains: Density functional theory, MpB model, and quantum spin transport studies

    Science.gov (United States)

    Oeiras, R. Y.; da Silva, E. Z.

    2014-04-01

    Carbon linear atomic chains attached to graphene have experimentally been produced. Motivated by these results, we study the nature of the carbon bonds in these nanowires and how it affects their electrical properties. In the present study we investigate chains with different numbers of atoms and we observe that nanowires with odd number of atoms present a distinct behavior than the ones with even numbers. Using graphene nanoribbons as leads, we identify differences in the quantum transport of the chains with the consequence that even and odd numbered chains have low and high electrical conduction, respectively. We also noted a dependence of current with the wire size. We study this unexpected behavior using a combination of first principles calculations and simple models based on chemical bond theory. From our studies, the electrons of carbon nanowires present a quasi-free electron behavior and this explains qualitatively the high electrical conduction and the bond lengths with unexpected values for the case of odd nanowires. Our study also allows the understanding of the electric conduction dependence with the number of atoms and their parity in the chain. In the case of odd number chains a proposed π-bond (MpB) model describes unsaturated carbons that introduce a mobile π-bond that changes dramatically the structure and transport properties of these wires. Our results indicate that the nature of bonds plays the main role in the oscillation of quantum electrical conduction for chains with even and odd number of atoms and also that nanowires bonded to graphene nanoribbons behave as a quasi-free electron system, suggesting that this behavior is general and it could also remain if the chains are bonded to other materials.

  6. Bond length and electric current oscillation of long linear carbon chains: Density functional theory, MpB model, and quantum spin transport studies

    Energy Technology Data Exchange (ETDEWEB)

    Oeiras, R. Y.; Silva, E. Z. da [Institute of Physics “Gleb Wataghin”, University of Campinas-Unicamp, 13083-859 Campinas, SP (Brazil)

    2014-04-07

    Carbon linear atomic chains attached to graphene have experimentally been produced. Motivated by these results, we study the nature of the carbon bonds in these nanowires and how it affects their electrical properties. In the present study we investigate chains with different numbers of atoms and we observe that nanowires with odd number of atoms present a distinct behavior than the ones with even numbers. Using graphene nanoribbons as leads, we identify differences in the quantum transport of the chains with the consequence that even and odd numbered chains have low and high electrical conduction, respectively. We also noted a dependence of current with the wire size. We study this unexpected behavior using a combination of first principles calculations and simple models based on chemical bond theory. From our studies, the electrons of carbon nanowires present a quasi-free electron behavior and this explains qualitatively the high electrical conduction and the bond lengths with unexpected values for the case of odd nanowires. Our study also allows the understanding of the electric conduction dependence with the number of atoms and their parity in the chain. In the case of odd number chains a proposed π-bond (MpB) model describes unsaturated carbons that introduce a mobile π-bond that changes dramatically the structure and transport properties of these wires. Our results indicate that the nature of bonds plays the main role in the oscillation of quantum electrical conduction for chains with even and odd number of atoms and also that nanowires bonded to graphene nanoribbons behave as a quasi-free electron system, suggesting that this behavior is general and it could also remain if the chains are bonded to other materials.

  7. 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......, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation....

  8. Control Networks in Paediatric Tourette Syndrome Show Immature and Anomalous Patterns of Functional Connectivity

    Science.gov (United States)

    Church, Jessica A.; Fair, Damien A.; Dosenbach, Nico U. F.; Cohen, Alexander L.; Miezin, Francis M.; Petersen, Steven E.; Schlaggar, Bradley L.

    2009-01-01

    Tourette syndrome (TS) is a developmental disorder characterized by unwanted, repetitive behaviours that manifest as stereotyped movements and vocalizations called "tics". Operating under the hypothesis that the brain's control systems may be impaired in TS, we measured resting-state functional connectivity MRI (rs-fcMRI) between 39 previously…

  9. 电针联合生物反馈治疗功能性大便失禁临床观察%The Clinical Observation of Electric Acupuncture Combined With Biofeedback Therapy for Patients With Functional Encopresis

    Institute of Scientific and Technical Information of China (English)

    鲁丹

    2015-01-01

    Objective The study was performed to observe the clinical curative effect of the electric acupuncture combined with biofeedback therapy treatment functional encopresis. Methods 62 patients with functional encopresis were voluntarily divided into two groups: treatment group (32 cases) and control group(30 cases).The treatment group was exposed to the electric acupuncture combined with biofeedback therapy. Patients in the control group only receiced the biofeedback therapy. To observe symptom change of functional encopresis.Results The total effective rate of the two group was 76.67% and 96.88% respectively. The treatment group is better than the control group.Conclusion The electric acupuncture combined with biofeedback therapy plays a positive role in treating functional encopresis.%目的:观察电针联合生物反馈治疗功能性大便失禁的临床疗效。方法患者自愿选择分为治疗组32例与对照组30例,治疗组采用电针联合生物反馈治疗,对照组采用生物反馈治疗,观察大便失禁改善情况。结果治疗组总有效率96.88%,对照组热总有效率76.67%,治疗组优于对照组(P<0.05)。结论电针联合生物反馈治疗功能行大便失禁疗效显著。

  10. Efficacy Observation on Functional Electrical Stimulation Combined with Rehabilitation Training for Hemiplegic after Stroke%功能性电刺激联合康复训练治疗脑卒中偏瘫疗效观察

    Institute of Scientific and Technical Information of China (English)

    任海; 何永红

    2013-01-01

    Objective: To investigate the efficacy of treating hemiplegic by functional electrical stimulation combined with rehabilitation training. Methods:60 cases of patients were randomly divided into experiment group and control group, on the basis of conventional rehabilitation training, the control adopted the conventional ambulation training, while the experiment group adopted functional electrical stimulation, and compared the effi-cacy of two groups. Results:The improvement of MMT, TUG, 10MWT and Barthel index in experiment group were all better than those in control group (P<0.05). Conclusion:The treatment of functional electrical stimulation combined with rehabilitation training has a great effect on motor func-tion recovery of patients with hemiplegic after stroke, which has a high application value.%  目的:探讨功能性电刺激联合康复训练对脑卒中偏瘫的康复效果。方法:将60例患者随机分为实验组和对照组,对照组在常规恢复性训练基础上增加常规步行训练,实验组则增加功能性电刺激步行训练,比较两组临床疗效。结果:实验组MMT、TUG、10MWT及Barthel指数改善程度均优于对照组(P<0.05)。结论:功能性电刺激联合康复训练对脑卒中偏瘫患者的运动功能恢复效果显著,具有较高的应用价值。

  11. Electrical Conductivity.

    Science.gov (United States)

    Hershey, David R.; Sand, Susan

    1993-01-01

    Explains how electrical conductivity (EC) can be used to measure ion concentration in solutions. Describes instrumentation for the measurement, temperature dependence and EC, and the EC of common substances. (PR)

  12. 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.

  13. Electrical injury

    Science.gov (United States)

    ... electricity, such as a rubber mat or folded newspapers. 4. Once the person is away from the ... Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier ...

  14. Characterization of solar cells for space applications. Volume 5: Electrical characteristics of OCLI 225-micron MLAR wraparound cells as a function of intensity, temperature, and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Miyahira, T. F.; Weiss, R. S.

    1979-01-01

    Computed statistical averages and standard deviations with respect to the measured cells for each intensity temperature measurement condition are presented. Display averages and standard deviations of the cell characteristics in a two dimensional array format are shown: one dimension representing incoming light intensity, and another, the cell temperature. Programs for calculating the temperature coefficients of the pertinent cell electrical parameters are presented, and postirradiation data are summarized.

  15. Electricity futures

    OpenAIRE

    Falbo P; Felletti, D; S. De Stefani

    2016-01-01

    This chapter describes forwards and futures for electricity currently traded in Europe and other markets. Due to the non-storability of electricity, spot prices are highly dependent on local supply and demand conditions, business activity, and weather conditions. Seasonality is also very strong during the day (peak versus off-peak hours), during the week, and during cold and hot seasons. As a consequence, liquidity is low and the day-to-day volatility is much higher than in financial ma...

  16. The Schema Features and Aesthetic Functions of the Foreign Language Teaching with Electric Audio-visual Aids%外语电化教学的图式特征与美育功能

    Institute of Scientific and Technical Information of China (English)

    齐欣

    2015-01-01

    外语电化教学对传统外语教学模式提出挑战的同时,其自身也面临着诸多的挑战,需要更多的理论支撑和功能研究。基于图式理论和美育教育,对外语电化教学图式特征及其隐性、感性、个性三种美育功能的创新审视,进一步丰富了外语电化教学的理论基础,并强调了其美育功能实现的必要性。%While the foreign language teaching with electric audio-visual aids brings about challenges to the traditional language teaching,it is also faced with many challenges,and more studies on its theoretical basis and functions are encouraged. On the basis of Schema Theory and aesthetic education,this paper makes an innovative examination of the schema features of foreign language teaching with electric audio-visual aids and its implicit,emotional,and personalized aesthetic functions,further enriches its theoretical basis and emphasizes the necessity of achieving its aesthetic functions.

  17. Analysis of biofeedback electrical stimulation combined with vaginal dumbbell on the recovery of postpartum pelvic muscle function%生物反馈电刺激结合阴道哑铃的临床效果浅析

    Institute of Scientific and Technical Information of China (English)

    于爱萍; 闫晓蓉; 王海燕

    2013-01-01

    Objective To assess the effect of biofeedback electrical stimulation combined with Vaginal dumbbell on the recovery of postpartum pelvic muscle function. Methods 122 cases of primiparous women after spontanecus delivery were selected in our hospital from June to September in 2012,who received 42-day recheck by the pelvic floor muscle strength of primary screening at the pelvic of 0 to 3. Then they were randomly divided into investigation group(62 cases) and control group (60 cases).Investigation group applied the low-frequency electrical stimulation combined with biofeedback with vaginal dumbbell. The control group used the low-frequency joint electrical stimulation biofeedback combined with shrinking anal exercises. Pelvic floor muscle strength recovery were compared between 2 groups of Patients after the treatment. Results The pelvic floor muscle strength in two groups of patients recoveried and improved at different level of 0 to 3 was significantly lower than the control group, the difference was statistically significant (P  生物反馈电刺激联合阴道哑铃在产后盆底康复中的治疗效果优于生物反馈电刺激配合单纯缩肛练习,值得临床推广。

  18. Wearable sensors for patient-specific boundary shape estimation to improve the forward model for electrical impedance tomography (EIT) of neonatal lung function

    International Nuclear Information System (INIS)

    Electrical impedance tomography (EIT) could be significantly advantageous to continuous monitoring of lung development in newborn and, in particular, preterm infants as it is non-invasive and safe to use within the intensive care unit. It has been demonstrated that accurate boundary form of the forward model is important to minimize artefacts in reconstructed electrical impedance images. This paper presents the outcomes of initial investigations for acquiring patient-specific thorax boundary information using a network of flexible sensors that imposes no restrictions on the patient's normal breathing and movements. The investigations include: (1) description of the basis of the reconstruction algorithms, (2) tests to determine a minimum number of bend sensors, (3) validation of two approaches to reconstruction and (4) an example of a commercially available bend sensor and its performance. Simulation results using ideal sensors show that, in the worst case, a total shape error of less than 6% with respect to its total perimeter can be achieved. (paper)

  19. Practical electrical engineering

    CERN Document Server

    N Makarov, Sergey; Bitar, Stephen J

    2016-01-01

    This textbook provides comprehensive, in-depth coverage of the fundamental concepts of electrical and computer engineering. It is written from an engineering perspective, with special emphasis on circuit functionality and applications. Reliance on higher-level mathematics and physics, or theoretical proofs has been intentionally limited in order to prioritize the practical aspects of electrical engineering. This text is therefore suitable for a number of introductory circuit courses for other majors such as robotics, mechanical, biomedical, aerospace, civil, architecture, petroleum, and industrial engineering. The authors’ primary goal is to teach the aspiring engineering student all fundamental tools needed to understand, analyze and design a wide range of practical circuits and systems. Their secondary goal is to provide a comprehensive reference, for both major and non-major students as well as practicing engineers. Provides a self-contained, fundamental textbook on electric circuits and basic electronic...

  20. Development and Evaluation of an Improved Technique for Pulmonary Function Testing Using Electrical Impedance Pneumography Intended for the Diagnosis of Chronic Obstructive Pulmonary Disease Patients

    OpenAIRE

    Myeong Heon Sim; Min Yong Kim; In Cheol Jeong; Sung Bin Park; Suk Joong Yong; Won Ky Kim; Hyung Ro Yoon

    2013-01-01

    Spirometry is regarded as the only effective method for detecting pulmonary function test (PFT) indices. In this study, a novel impedance pulmonary function measurement system (IPFS) is developed for directly assessing PFT indices. IPFS can obtain high resolution values and remove motion artifacts through real-time base impedance feedback. Feedback enables the detection of PFT indices using only both hands for convenience. IPFS showed no differences in the sitting, supine, and standing postur...

  1. Application of Functional Electrical Stimulation and Brain Computer Interface in Medicine%功能性电刺激与脑机接口在医学中的应用

    Institute of Scientific and Technical Information of China (English)

    隋宝石; 万柏坤

    2011-01-01

    To review the application of functional electrical stimulation (FES) on treatment of motor dysfunction and dysphagia induced by brain or spinal cord injury, and introduce the application of brain computer interface in modern medicine and the progress of BCI-based FES. The results show that BCI, FES and BCI-based FES are good prospect of new technology in modern rehabilitation engineering area.%本文回顾了功能性电刺激(Functional Electrical Stimulation,FES)在治疗脑损伤和脊髓损伤所造成的运动功能和吞咽障碍方面的应用;总结了脑机接口(Brain Computer Interface,BCI)技术在现代医学中的应用以及基于BCI的FES的研究现状.结果 显示,BCI、FES及二者相结合技术在现代康复工程领域中是极具应用前景的新技术.

  2. Power distribution automating system of Chugoku Electric Power Company (function to link with high-voltage system control); Chugoku Denryoku (kabu) haiden jidoka system. Koatsu keito kanri system tono renkei kino

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-01-10

    Chugoku Electric Power and Fuji Electric have developed a function to save man-power in data maintenance work in power distribution systems, whose data keep changing due to everyday work, by means of linking a high-voltage system control system with a power distribution automating system. The features of this function may be summarized as follows: (1) the linkage is performed by using the standard protocol (TCP/IP); (2) high-voltage distribution facility data are linked in units of construction names in the distribution systems, making facility data maintenance of the systems possible without a need of inputting data in the power distribution automating system; (3) data are linked periodically on the number of customers in a switch section and on change in facility capacity, with renewal enabled; and (4) linked data and the data on the power distribution automating system side are compared, when consistency in switch and device attributes, network and section facility data is checked automatically. (NEDO)

  3. Electric vehicle system for charging and supplying electrical power

    Science.gov (United States)

    Su, Gui Jia

    2010-06-08

    A power system that provides power between an energy storage device, an external charging-source/load, an onboard electrical power generator, and a vehicle drive shaft. The power system has at least one energy storage device electrically connected across a dc bus, at least one filter capacitor leg having at least one filter capacitor electrically connected across the dc bus, at least one power inverter/converter electrically connected across the dc bus, and at least one multiphase motor/generator having stator windings electrically connected at one end to form a neutral point and electrically connected on the other end to one of the power inverter/converters. A charging-sourcing selection socket is electrically connected to the neutral points and the external charging-source/load. At least one electronics controller is electrically connected to the charging-sourcing selection socket and at least one power inverter/converter. The switch legs in each of the inverter/converters selected by the charging-source/load socket collectively function as a single switch leg. The motor/generators function as an inductor.

  4. 7 CFR 1700.28 - Electric Program.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Electric Program. 1700.28 Section 1700.28 Agriculture... GENERAL INFORMATION Agency Organization and Functions § 1700.28 Electric Program. RUS, through the Electric Program, makes loans and loan guarantees for rural electrification and the furnishing of...

  5. Design of an electric energy meter with fault monitoring and remote reporting error function%一种具有故障监测及远程报错功能的电能表设计

    Institute of Scientific and Technical Information of China (English)

    沈庆; 瞿遂春; 邱爱兵

    2016-01-01

    文中针对目前市场上单相电子式电能表发生故障不易监测的问题,设计了一种具有自动故障监测及远程报错功能的电能表。本设计采用高精度单相电能计量芯片 ADE7755采集用户所使用的电量,采用高可靠性的RS485传输协议进行数据传输,使用高性能的单片机 STC89C52来作为整个电能采集、故障检测、数据传输电路的控制核心。构建了整个电能计量电路的组成框图、单相电能测量电路图以及软件流程图,最后对样机进行了试验,对试验结果进行了分析,实验结果表明该电能计量电路具有较高的监测精度。%In this paper, we design a power meter with automatic fault monitoring and remote report and error function in the current market. This design using high-precision single-phase electric power measurement chip ADE7755 collection of user and the high reliability of RS485 communication protocol for data transmission, using high performance microcontroller STC89C52 as the electric energy acquisition, fault detection and data transmission circuit control of the core. Construction of the whole electric energy metering circuit composition block diagram, single-phase electric can measuring circuit diagram and software flow chart. Finally, the prototype tests are carried out on the test results were analyzed. The experimental results show that the electric energy metering circuit has high monitoring precision.

  6. 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.

  7. Electricity Demand in Pakistan: A Nonlinear Estimation

    OpenAIRE

    Saima Nawaz; Nasir Iqbal; Saba Anwar

    2013-01-01

    This study attempts to estimate the electricity demand function for Pakistan using smooth transition autoregressive model over the period 1971-2012. The empirical results have shown that there is nonlinear relationship between electricity consumption and economic growth and also between electricity prices and consumption. The income elasticity of electricity is high while price elasticity is less than unity. Further, results have shown that the average real prices are below the optimal level....

  8. 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

  9. Regulation of the Deposition Morphology of Inkjet-Printed Crystalline Materials via Polydopamine Functional Coatings for Highly Uniform and Electrically Conductive Patterns.

    Science.gov (United States)

    Liu, Liang; Ma, Siyuan; Pei, Yunheng; Xiong, Xiao; Sivakumar, Preeth; Singler, Timothy J

    2016-08-24

    We report a method to achieve highly uniform inkjet-printed silver nitrate (AgNO3) and a reactive silver precursor patterns on rigid and flexible substrates functionalized with polydopamine (PDA) coatings. The printed AgNO3 patterns on PDA-coated substrates (glass and polyethylene terephthalate (PET)) exhibit a narrow thickness distribution ranging between 0.9 and 1 μm in the line transverse direction and uniform deposition profiles in the line axial direction. The deposited reactive silver precursor patterns on PDA-functionalized substrates also show "dome-shaped" morphology without "edge-thickened" structure due to "coffee-stain" effect. We posit that the highly uniform functional ink deposits formed on PDA-coated substrates are attributable to the strong binding interaction between the abundant catecholamine moieties at the PDA surface and the metallic silver cations (Ag(+) or Ag(NH3)(2+)) in the solutal inks. During printing of the ink rivulet and solvent evaporation, the substrate-liquid ink (S-L) interface is enriched with the silver-based cations and a solidification at the S/L interface is induced. The preferential solidification initiated at the S-L interface is further verified by the in situ visualization of the dynamic solidification process during solvent evaporation, and results suggest an enhanced crystal nucleation and growth localized at the S-L interface on PDA functionalized substrates. This interfacial interaction mediates solute transport in the liquid phase, resulting in the controlled enrichment of solute at the S-L interface and mitigated solute precipitation in both the contact line region and the liquid ink-vapor (L-V) interface due to evaporation. This mediated transport contributes to the final uniform solid deposition for both types of ink systems. This technique provides a complementary strategy for achieving highly uniform inkjet-printed crystalline structures, and can serve as an innovative foundation for high-precision additive

  10. Regulation of the Deposition Morphology of Inkjet-Printed Crystalline Materials via Polydopamine Functional Coatings for Highly Uniform and Electrically Conductive Patterns.

    Science.gov (United States)

    Liu, Liang; Ma, Siyuan; Pei, Yunheng; Xiong, Xiao; Sivakumar, Preeth; Singler, Timothy J

    2016-08-24

    We report a method to achieve highly uniform inkjet-printed silver nitrate (AgNO3) and a reactive silver precursor patterns on rigid and flexible substrates functionalized with polydopamine (PDA) coatings. The printed AgNO3 patterns on PDA-coated substrates (glass and polyethylene terephthalate (PET)) exhibit a narrow thickness distribution ranging between 0.9 and 1 μm in the line transverse direction and uniform deposition profiles in the line axial direction. The deposited reactive silver precursor patterns on PDA-functionalized substrates also show "dome-shaped" morphology without "edge-thickened" structure due to "coffee-stain" effect. We posit that the highly uniform functional ink deposits formed on PDA-coated substrates are attributable to the strong binding interaction between the abundant catecholamine moieties at the PDA surface and the metallic silver cations (Ag(+) or Ag(NH3)(2+)) in the solutal inks. During printing of the ink rivulet and solvent evaporation, the substrate-liquid ink (S-L) interface is enriched with the silver-based cations and a solidification at the S/L interface is induced. The preferential solidification initiated at the S-L interface is further verified by the in situ visualization of the dynamic solidification process during solvent evaporation, and results suggest an enhanced crystal nucleation and growth localized at the S-L interface on PDA functionalized substrates. This interfacial interaction mediates solute transport in the liquid phase, resulting in the controlled enrichment of solute at the S-L interface and mitigated solute precipitation in both the contact line region and the liquid ink-vapor (L-V) interface due to evaporation. This mediated transport contributes to the final uniform solid deposition for both types of ink systems. This technique provides a complementary strategy for achieving highly uniform inkjet-printed crystalline structures, and can serve as an innovative foundation for high-precision additive

  11. Decentralized adaptive robust control based on sliding mode and nonlinear compensator for the control of ankle movement using functional electrical stimulation of agonist-antagonist muscles

    Science.gov (United States)

    Kobravi, Hamid-Reza; Erfanian, Abbas

    2009-08-01

    A decentralized control methodology is designed for the control of ankle dorsiflexion and plantarflexion in paraplegic subjects with electrical stimulation of tibialis anterior and calf muscles. Each muscle joint is considered as a subsystem and individual controllers are designed for each subsystem. Each controller operates solely on its associated subsystem, with no exchange of information between the subsystems. The interactions between the subsystems are taken as external disturbances for each isolated subsystem. In order to achieve robustness with respect to external disturbances, unmodeled dynamics, model uncertainty and time-varying properties of muscle-joint dynamics, a robust control framework is proposed which is based on the synergistic combination of an adaptive nonlinear compensator with a sliding mode control and is referred to as an adaptive robust control. Extensive simulations and experiments on healthy and paraplegic subjects were performed to demonstrate the robustness against the time-varying properties of muscle-joint dynamics, day-to-day variations, subject-to-subject variations, fast convergence, stability and tracking accuracy of the proposed method. The results indicate that the decentralized robust control provides excellent tracking control for different reference trajectories and can generate control signals to compensate the muscle fatigue and reject the external disturbance. Moreover, the controller is able to automatically regulate the interaction between agonist and antagonist muscles under different conditions of operating without any preprogrammed antagonist activities.

  12. Electrical cardioversion

    International Nuclear Information System (INIS)

    External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The success rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately performed. (author)

  13. Optical and Electrical Properties of Nanostructured Metallic Electrical Contacts

    CERN Document Server

    Toranzos, Victor J; Mochán, W Luis; Zerbino, Jorge O

    2016-01-01

    We study the optical and electrical properties of silver films with a graded thickness obtained through metallic evaporation in vacuum on a tilted substrate to evaluate their use as semitransparent electrical contacts. We measure their ellipsometric coefficients, optical transmissions and electrical conductivity for different widths, and we employ an efficient recursive method to calculate their macroscopic dielectric function, their optical properties and their microscopic electric fields. The topology of very thin films corresponds to disconnected islands, while very wide films are simply connected. For intermediate widths the film becomes semicontinuous, multiply connected, and its microscopic electric field develops hotspots at optical resonances which appear near the percolation threshold of the conducting phase, yielding large ohmic losses that increase the absorptance above that of a corresponding homogeneous film. Optimizing the thickness of the film to maximize its transmittance above the percolation...

  14. Towards the hybrid organic semiconductor fet (hosfet) : electrical and electrochemical characterization of functionalized and unfunctionalized, covalently bound organic monolayers on silicon surfaces

    OpenAIRE

    Faber, Erik Jouwert

    2006-01-01

    Since their introduction in 1993 the class of covalently bound organic monolayers on oxide free silicon surfaces have found their way to multiple application fields such as passivation layers in solar cells, masking layers in lithographic processing, insulating films in hybrid moleculesilicon electronics, and memory devices. Furthermore, these monolayers can easily be functionalized with a large variety of receptor groups or sensing moieties, thereby forming a new promising material for incor...

  15. Functionally distinct sodium channels in ventricular epicardial and endocardial cells contribute to a greater sensitivity of the epicardium to electrical depression

    OpenAIRE

    Cordeiro, J. M.; Mazza, M.; Goodrow, R.; Ulahannan, N.; Antzelevitch, C; DI DIEGO, J.M.

    2008-01-01

    A greater depression of the action potential (AP) of the ventricular epicardium (Epi) versus endocardium (Endo) is readily observed in experimental models of acute ischemia and Brugada syndrome. Endo and Epi differences in transient outward K+ current and/or ATP-sensitive K+ channel current are believed to contribute to the differential response. The present study tested the hypothesis that the greater sensitivity of Epi is due in part to its functionally distinct early fast Na+ current (INa)...

  16. Development and Evaluation of an Improved Technique for Pulmonary Function Testing Using Electrical Impedance Pneumography Intended for the Diagnosis of Chronic Obstructive Pulmonary Disease Patients

    Directory of Open Access Journals (Sweden)

    Myeong Heon Sim

    2013-11-01

    Full Text Available Spirometry is regarded as the only effective method for detecting pulmonary function test (PFT indices. In this study, a novel impedance pulmonary function measurement system (IPFS is developed for directly assessing PFT indices. IPFS can obtain high resolution values and remove motion artifacts through real-time base impedance feedback. Feedback enables the detection of PFT indices using only both hands for convenience. IPFS showed no differences in the sitting, supine, and standing postures during the measurements, indicating that patient posture has no effect on IPFS. Mean distance analysis showed good agreement between the volume and flow signal of IPFS (p < 0.05. PFT indices were detected in subjects to differentiate a chronic obstructive pulmonary disease (COPD patient group from a normal group. The forced vital capacity (FVC, forced expiratory volume in the first second (FEV1, FEV1/FVC, and peak expiratory flow (PEF in the COPD group were lower than those in the normal group by IPFS (p < 0.05. IPFS is therefore suitable for evaluating pulmonary function in normal and COPD patients. Moreover, IPFS could be useful for periodic monitoring of existing patients diagnosed with obstructive lung disease.

  17. Research of Brain-Controlled Wheelchair Obstacle Avoidance System Based on Ultrasonic Sensor%基于超声波传感器的脑控轮椅避障系统的研究

    Institute of Scientific and Technical Information of China (English)

    刘甜; 李远清; 王洪涛; 胡友盼

    2012-01-01

    A method of obstacle avoidance is proposed aimed at the phenomenon of collision accident likely caused by the non-stationary nature of the electroencephalogram (EEG) signals while the users steer the brain-controlled wheelchair. Multi-channel ultrasonic sensors obstacle avoidance system and a feedback interface used for obstacle avoidance alert are also designed. The prompt messages displayed on the feedback interface will assist the users to make effective obstacle avoidance decisions. If the wheelchair can't avoid obstacle successfully when the users apply their EEG signals to steer the wheelchair autonomously, the system will send messages to stop the wheelchair immediately to avoid collision with obstacles, which ensures the personal safety of the wheelchair users. The experimental results of brain - controlled wheelchair show that when the safety area critical value and the emergency stop distance critical value of the front and back are respectively set as 500 millimeters, 400 millimeters and 200 millimeters, the obstacle avoidance system with good stability and strong real -time property can meet the needs of brain -controlled wheelchair users' safety navigation.%针对脑控轮椅行驶时因用户脑电信号的不稳定性可能引起碰撞事故发生的现象,提出了一种避障方法,并设计了多路超声波传感器避障系统及避障提示反馈界面;反馈界面上实时显示的提示信息将辅助用户做出有效的避障决策;当用户采用脑电自主控制轮椅运行时,若无法成功避障,则该避障系统立即启动紧急停车功能以避免与障碍物发生碰撞,保证了脑控轮椅用户的人身安全;实验结果表明:当把安全区域临界值、前后及左右紧急停车距离临界值分别设置为500mm、400mm和200mm时,该超声波传感器避障系统稳定性好、实时性强,能够满足脑控轮椅的用户安全导航的需要.

  18. Estimating Elasticity for Residential Electricity Demand in China

    OpenAIRE

    G. Shi; Zheng, X; Song, F

    2012-01-01

    Residential demand for electricity is estimated for China using a unique household level dataset. Household electricity demand is specified as a function of local electricity price, household income, and a number of social-economic variables at household level. We find that the residential demand for electricity responds rather sensitively to its own price in China, which implies that there is significant potential to use the price instrument to conserve electricity consumption. Electricity e...

  19. Gastric potential difference measurements. The gastric mucosal integrity and function studied with a new method for measurement of the electric potential difference across the stomach wall

    DEFF Research Database (Denmark)

    Højgaard, L

    1991-01-01

    be reduced by allopurinol pretreatment, possibly due to the inhibition of oxygen-derived free radical formation. Gastric PD and pH were measured in volunteers and duodenal ulcer patients during Stroop's color word conflict test, in which mental stress causes sympathetic activation. A PD reduction and a p......H increase were found along with stress induction, thereby indicating an influence of mental stress on stomach mucosal function. It is concluded that gastric PD measurement may be useful in ulcer pathogenetic research, and a sufficient gastric mucosal blood flow is stressed as being important for the mucosal...

  20. Electrical machine

    Energy Technology Data Exchange (ETDEWEB)

    De Bock, Hendrik Pieter Jacobus; Alexander, James Pellegrino; El-Refaie, Ayman Mohamed Fawzi; Gerstler, William Dwight; Shah, Manoj Ramprasad; Shen, Xiaochun

    2016-06-21

    An apparatus, such as an electrical machine, is provided. The apparatus can include a rotor defining a rotor bore and a conduit disposed in and extending axially along the rotor bore. The conduit can have an annular conduit body defining a plurality of orifices disposed axially along the conduit and extending through the conduit body. The rotor can have an inner wall that at least partially defines the rotor bore. The orifices can extend through the conduit body along respective orifice directions, and the rotor and conduit can be configured to provide a line of sight along the orifice direction from the respective orifices to the inner wall.

  1. Electricity supply

    International Nuclear Information System (INIS)

    In the 1960's and early 1970s, nuclear power plants offered economic and environmental advantages over coal plants; most were completed on time and at reasonable cost and still operate today, providing economical, reliable electricity. In the 1970s, a series of events, beginning with the 1973-74 recession and culminating with the Three Mile Island accident, adversely affected the nuclear industry. According to experts, reviving the nuclear option requires increased public acceptance and reduced financial risks. The public's concerns about safety need to be allayed through the safe, efficient operation of current plants and improved designs

  2. Solar Electricity

    Science.gov (United States)

    1988-01-01

    ARCO Solar manufactures PV Systems tailored to a broad variety of applications. PV arrays are routinely used at remote communications installations to operate large microwave repeaters, TV and radio repeaters rural telephone, and small telemetry systems that monitor environmental conditions. Also used to power agricultural water pumping systems, to provide electricity for isolated villages and medical clinics, for corrosion protection for pipelines and bridges, to power railroad signals, air/sea navigational aids, and for many types of military systems. ARCO is now moving into large scale generation for utilities.

  3. Effects of neuromuscular electrical stimulation and aerobic exercise training on arterial stiffness and autonomic functions in patients with chronic heart failure.

    Science.gov (United States)

    Dobšák, Petr; Tomandl, Josef; Spinarova, Lenka; Vitovec, Jiri; Dusek, Ladislav; Novakova, Marie; Jarkovsky, Jiri; Krejci, Jan; Hude, Petr; Honek, Tomáš; Siegelova, Jarmila; Homolka, Pavel

    2012-10-01

    Neuromuscular electrical stimulation (NMES) of leg muscles has been introduced in clinical practice as a rehabilitation (RHB) method in patients with chronic heart failure (CHF); however, the role of NMES on the reduction of arterial stiffness and autonomic disbalance in these patients has not yet been studied. Sixty-one patients with stable CHF (mean age 58.9 [2.1] years; mean ejection fraction 31 [4.2]%, New York Heart Association II-III) were randomly assigned into two groups. Patients in (i) exercise training group (ET; n = 30) underwent 12 weeks of bicycle ET (3 × 40 min/week); (ii) group NMES (n = 31) performed 12 weeks of NMES of quadriceps and calf muscles (frequency 10 Hz, mode "20 s on-20 s off," intensity 60 mA), 2 × 60 min/day. Noninvasive assessment of arterial stiffness was done using the cardio-ankle vascular index (CAVI). CAVI and heart rate variability (HRV) and ·VO(2peak) were evaluated before and after RHB program. Both types of RHB reduced significantly CAVI (ET from 9.6 [0.2] to 8.9 [0.2], P < 0.012; NMES from 9.3 [0.2] to 8.7 [0.2], P < 0.013), increased high frequency (HF) component of HRV (+65.6%; P = 0.001) and decreased ratio of low frequency (LF) component with HF component (LF/HF ratio) in group ET (-39.8%; P < 0.001). Changes of HRV parameters in group NMES were not significant; however, a marked tendency to autonomic stabilization was present. Both types of RHB led also to significant increase of ·VO(2peak) (ET from 18.7 [0.7] to 20.8 [0.7] mL/kg/min, P < 0.004; NMES from 17.3 [0.7] to 19.0 [0.7] mL/kg/min, P < 0.001). ET or NMES has been shown to improve significantly arterial stiffness and to stabilize autonomic balance.

  4. Effects of neuromuscular electrical stimulation and aerobic exercise training on arterial stiffness and autonomic functions in patients with chronic heart failure.

    Science.gov (United States)

    Dobšák, Petr; Tomandl, Josef; Spinarova, Lenka; Vitovec, Jiri; Dusek, Ladislav; Novakova, Marie; Jarkovsky, Jiri; Krejci, Jan; Hude, Petr; Honek, Tomáš; Siegelova, Jarmila; Homolka, Pavel

    2012-10-01

    Neuromuscular electrical stimulation (NMES) of leg muscles has been introduced in clinical practice as a rehabilitation (RHB) method in patients with chronic heart failure (CHF); however, the role of NMES on the reduction of arterial stiffness and autonomic disbalance in these patients has not yet been studied. Sixty-one patients with stable CHF (mean age 58.9 [2.1] years; mean ejection fraction 31 [4.2]%, New York Heart Association II-III) were randomly assigned into two groups. Patients in (i) exercise training group (ET; n = 30) underwent 12 weeks of bicycle ET (3 × 40 min/week); (ii) group NMES (n = 31) performed 12 weeks of NMES of quadriceps and calf muscles (frequency 10 Hz, mode "20 s on-20 s off," intensity 60 mA), 2 × 60 min/day. Noninvasive assessment of arterial stiffness was done using the cardio-ankle vascular index (CAVI). CAVI and heart rate variability (HRV) and ·VO(2peak) were evaluated before and after RHB program. Both types of RHB reduced significantly CAVI (ET from 9.6 [0.2] to 8.9 [0.2], P < 0.012; NMES from 9.3 [0.2] to 8.7 [0.2], P < 0.013), increased high frequency (HF) component of HRV (+65.6%; P = 0.001) and decreased ratio of low frequency (LF) component with HF component (LF/HF ratio) in group ET (-39.8%; P < 0.001). Changes of HRV parameters in group NMES were not significant; however, a marked tendency to autonomic stabilization was present. Both types of RHB led also to significant increase of ·VO(2peak) (ET from 18.7 [0.7] to 20.8 [0.7] mL/kg/min, P < 0.004; NMES from 17.3 [0.7] to 19.0 [0.7] mL/kg/min, P < 0.001). ET or NMES has been shown to improve significantly arterial stiffness and to stabilize autonomic balance. PMID:22882472

  5. Investigation of potential artefactual changes in measurements of impedance changes during evoked activity: implications to electrical impedance tomography of brain function.

    Science.gov (United States)

    Aristovich, Kirill Y; Dos Santos, Gustavo S; Holder, David S

    2015-06-01

    Electrical impedance tomography (EIT) could provide images of fast neural activity in the adult human brain with a resolution of 1 ms and 1 mm by imaging impedance changes which occur as ion channels open during neuronal depolarization. The largest changes occur at dc and decrease rapidly over 100 Hz. Evoked potentials occur in this bandwidth and may cause artefactual apparent impedance changes if altered by the impedance measuring current. These were characterized during the compound action potential in the walking leg nerves of Cancer pagurus, placed on Ag/AgCl hook electrodes, to identify how to avoid artefactual changes during brain EIT. Artefact-free impedance changes (δZ) decreased with frequency from -0.045 ± 0.01% at 225 Hz to -0.02 ± 0.01% at 1025 Hz (mean ± 1 SD, n = 24 in 12 nerves) which matched changes predicted by a finite element model. Artefactual δZ reached c.300% and 50% of the genuine membrane impedance change at 225 Hz and 600 Hz respectively but decreased with frequency of the applied current and was negligible above 1 kHz. The proportional amplitude (δZ (%)) of the artefact did not vary significantly with the amplitude of injected current of 5-20 µA pp. but decreased significantly from -0.09 ± 0.024 to -0.03 ± 0.023% with phase of 0 to 45°. For fast neural EIT of evoked activity in the brain, artefacts may arise with applied current of >10 µA. Independence of δZ with respect to phase but not the amplitude of applied current controls for them; they can be minimized by randomizing the phase of the applied measuring current and excluded by recording at >1 kHz. PMID:26009486

  6. SnO2透明导电膜的结构性能及光电特性分析%Analysis on the Structural Function and Photoelectric Character of SnO2 Transparent Electric Conductive Film

    Institute of Scientific and Technical Information of China (English)

    李望

    2011-01-01

    To achieve zoom function by changing the liquid shape, SnO2:F transparent electric conductive film was placed evenly in a small quartz tube with the ultrasonic spray pyrolysis deposition technique. and a layer of transparent electrode was deposited in turn along the inside cylinder glass tube. so that the conduetive liquid and electrodes form a capacitor. Voltage was applied at both ends to change the dielectric layer of conductive liquid and the interfacial tension effectively. The paper analyzed and tested the SnO2 transparent electric conductive film's strutural function and photoelectric character to rescarch the influence of different temperature and film thickness to the film's photoelectric character.%本文采用超声喷雾热解淀积技术将SnO2∶F透明导电薄膜均匀制备于小尺寸石英管内,使玻璃圆柱体的内壁依次沉积了一层透明电极,使导电液体和电极形成一个电容,在其两端施加电压可以有效的改变导电液体与介电层之间的界面张力,即改变液体的界面形状,从而实现变焦透镜的功能.通过对SnO2导电薄膜结构性能及光电特性的分析和测试,研究了不同温度和薄膜厚度对薄膜光电性能的影响.

  7. 盆底功能康复低频电刺激治疗产后尿潴留%The effect of the pelvic floor muscle function recovery low frequency electrical stimulation treatment on the post -labour urine retention

    Institute of Scientific and Technical Information of China (English)

    张巍颖; 李云; 胡艳

    2010-01-01

    Objective To discuss the clinical efficacy of the pelvic floor muscle function recovery low frequency electrical stimulation treatment on the post - labour urine retention. Methods From Aug 2008 to Aug 2009, 36 patients who were after 6 ~ 8 hours of vaginal delivery had difficulty urinate herself, and the methods including heating the water flow, warm pad and message the bladder area, neostigmine had no effect. The patients were given low frequency electrical stimulation treatment, 20 minute twice per day. Results Among 36 patients, 26 cases got urinate well after twice treatment course, and 10 cases got urinate well and residue urine volume <50 ml was measured by ultrasound after 4 treatment course. Conclusions Pelvic floor muscle function recovery low frequency electrical stimulation treatment for the post - labour urine retention has obvious efficacy, and easy manipulate, safe, reproducible, painless, which is worth to promoting.%目的 探讨盆底功能康复低频电刺激治疗产后尿潴留临床效果.方法 选取我院2008年8月~2009年8月经阴道分娩后6~8 h不能自动排尿,经各种诱导排尿如听流水声、热敷膀胱区加按摩、肌肉注射新斯的明等一般处理无效36例困难产后尿潴留患者进行盆底功能康复低频电刺激治疗,每日2次,每次20 min.结果 26例困难产后尿潴留患者经2次治疗后排尿顺畅,10例患者经4次治疗后排尿顺畅且经B超测残余尿<50 ml.结论 盆底功能康复低频电刺激治疗产后尿潴留效果显著,操作方法简单、安全、可重复性,病人无痛苦,值得临床推广.

  8. Electrically driven optical metamaterials

    Science.gov (United States)

    Le-van, Quynh; Le Roux, Xavier; Aassime, Abdelhanin; Degiron, Aloyse

    2016-06-01

    The advent of metamaterials more than 15 years ago has offered extraordinary new ways of manipulating electromagnetic waves. Yet, progress in this field has been unequal across the electromagnetic spectrum, especially when it comes to finding applications for such artificial media. Optical metamaterials, in particular, are less compatible with active functionalities than their counterparts developed at lower frequencies. One crucial roadblock in the path to devices is the fact that active optical metamaterials are so far controlled by light rather than electricity, preventing them from being integrated in larger electronic systems. Here we introduce electroluminescent metamaterials based on metal nano-inclusions hybridized with colloidal quantum dots. We show that each of these miniature blocks can be individually tuned to exhibit independent optoelectronic properties (both in terms of electrical characteristics, polarization, colour and brightness), illustrate their capabilities by weaving complex light-emitting surfaces and finally discuss their potential for displays and sensors.

  9. Electrically driven optical metamaterials.

    Science.gov (United States)

    Le-Van, Quynh; Le Roux, Xavier; Aassime, Abdelhanin; Degiron, Aloyse

    2016-06-22

    The advent of metamaterials more than 15 years ago has offered extraordinary new ways of manipulating electromagnetic waves. Yet, progress in this field has been unequal across the electromagnetic spectrum, especially when it comes to finding applications for such artificial media. Optical metamaterials, in particular, are less compatible with active functionalities than their counterparts developed at lower frequencies. One crucial roadblock in the path to devices is the fact that active optical metamaterials are so far controlled by light rather than electricity, preventing them from being integrated in larger electronic systems. Here we introduce electroluminescent metamaterials based on metal nano-inclusions hybridized with colloidal quantum dots. We show that each of these miniature blocks can be individually tuned to exhibit independent optoelectronic properties (both in terms of electrical characteristics, polarization, colour and brightness), illustrate their capabilities by weaving complex light-emitting surfaces and finally discuss their potential for displays and sensors.

  10. Uncertainty contribution of a wind turbine to the electric field of a DVOR antenna as a function of wind direction and rotor position

    Science.gov (United States)

    Sandmann, Sergei; Garbe, Heyno

    2016-09-01

    The presence of a wind turbine (WT) has the potential to distort electromagnetic fields emitted by terrestrial radio navigation aids. In this paper especially the field distortion of a Doppler Very High Frequency Omnidirectional Radio Range (DVOR) surveillance navigation system is investigated as a function of wind direction and rotor position. Therefor, the field distribution of a DVOR is simulated in the surrounding of a WT for 104 combinations of the angles of wind direction and rotor position. Furthermore, these calculations are executed for two different rotor diameters and 10 steps of distance between DVOR and WT in the range of 10 km. Based on the calculated data a method to estimate the maximum field distortion is developed. It is shown that the presented method allows to approximate the worst case field distortion with the results of two general simulation setups. Eliminating the need of simulating all possible geometric constellations of the WT this method hereby offers the benefit of significantly reduced simulation effort.

  11. Electricity supply

    International Nuclear Information System (INIS)

    In the 1960s and early 1970s, nuclear power plants offered economic and environmental advantages over coal plants; most were completed on time and at reasonable cost and still operate today, providing economical, reliable electricity. In the 1970s, a series of events, beginning with the 1973-74 recession and culminating with the Three Mile Island accident, adversely affected the nuclear industry. This report discusses how reviving the nuclear option requires increased public acceptance and reduced financial risks. The public's concerns about safety need to be allayed through the safe, efficient operation of current plants and improved designs. In addition, escalating costs-stemming in part form an outmoded licensing process and unanticipated actions by state agencies and public interest groups-must be alleviated

  12. Electric field distribution of electron emitter surfaces

    Science.gov (United States)

    Tagawa, M.; Takenobu, S.; Ohmae, N.; Umeno, M.

    1987-03-01

    The electric field distribution of a tungsten field emitter surface and a LaB6 thermionic emitter surface has been studied. The computer simulation of electric field distribution on the emitter surface was carried out with a charge simulation method. The electric field distribution of the LaB6 thermionic emitter was experimentally evaluated by the Schottky plot. Two independent equations are necessary for obtaining local electric field and work function; the Fowler-Nordheim equation and the equation of total energy distribution of emitted electron being used to evaluate the electric field distribution of the tungsten field emitter. The experimental results agreed with the computer simulation.

  13. 辅以功能电刺激的实时步态训练与反馈分析系统%Real-time Gait Training System with Embedded Functional Electrical Stimulation

    Institute of Scientific and Technical Information of China (English)

    顾琳燕; 阮兆明; 贾桂锋; 夏静; 裘利坚; 吴长旺; 金肖青; 宁钢民

    2015-01-01

    To solve the problem that mostly gait analysis is independent from the treatment, this work proposes a system that integrates the functions of gait training and assessment for foot drop treatment. The system uses a set of sensors to col ect gait parameters and designes multi-mode functional electrical stimulators as actuator. Body area network technology is introduced to coordinate the data communication and execution of the sensors and stimulators, synchronize the gait analysis and foot drop treatment. Bluetooth 4.0 is applied to low the power consumption of the system. The system realizes the synchronization of treatment and gait analysis. It is able to acquire and analyze the dynamic parameters of ankle, knee and hip in real-time, and treat patients by guiding functional electrical stimulation delivery to the specific body locations of patients.%该文研究设计了同步实现足下垂患者步态训练和康复评估的综合系统,以解决目前存在的足下垂治疗与步态分析分离的不足。系统采用多传感器采集各运动部位的参数,并设计了多重模式的功能性电刺激装置,引入了体域网技术协调传感器和刺激器的数据通讯及控制,同步实现步态实时分析与足下垂治疗。体域网应用了蓝牙4.0技术以降低系统功耗。系统实现了治疗与评估的同步,能够实时采集并分析训练时踝、膝、髋等部位运动参数,并同时对患病部位进行功能性电刺激治疗。

  14. Electric Dipole Moment Experiment Systematic from Electric Field Discharge Current

    Science.gov (United States)

    Feinberg, B.; Gould, Harvey

    2014-09-01

    A magnetic field, in the direction of the electric field and synchronous with the electric field reversal, will mimic an EDM signal. One might expect a discharge across the electric field plates to produce magnetic fields with only small or vanishing components parallel to the electric field, minimizing its systematic effect. Our experimental model, using simulated discharge currents, found otherwise: the discharge current may be at an angle to the normal, and thus generate a normal magnetic field. Comparison of data from the experimental model with the results from calculations will be presented, along with estimates of the time-averaged normal magnetic field seen by atoms in an electron EDM experiment using a fountain of laser-cooled francium, as a function of discharge current.

  15. Topics on electricity trade

    Energy Technology Data Exchange (ETDEWEB)

    Skytte, K.

    2001-07-01

    being unable to fulfil the commitments made on the spot market. The disclosed cost of using the regulating power market is a quadratic function of the amount of regulation. This asymmetric cost may encourage bidders with fluctuating production to be more strategic in their way of bidding on the spot market. By using such strategies the extra costs (for e.g. wind power) needed to counter unpredictable fluctuations may be limited. The fourth paper applies the findings in the previous paper to show how a supplier with a 'controllable' production will make strategic bids on the power exchange - in this case a heat pump. The fifth paper discusses the design of the regulating power market and what the choice of design means for suppliers with fluctuating production, e.g. wind turbines. It is found that not only does the accuracy of the wind prediction influence the use of the power exchange, but the structure of the power exchange itself may also play an important role. Several studies of the northern European electricity liberalisation have concluded that developments of a liberalised electricity market and cross border trade can be of benefit for the consumers and bring along a global environmental improvement. All these studies have assumed that a perfect competitive electricity market can be obtained. A number of imperfections, which inevitably will arise, have not been taken into account, - at least in the transition period. These imperfections can be technical, economic or tradition-bound, but may have political characteristics as well. The sixth paper in this thesis surveys those market imperfections which are most likely to appear. Market imperfections can, for example, have structural or political characteristics that imply non-optimal competitive behaviour, e.g., the means to achieve political goals may hinder the desirable effects of the liberalisation. This can, for example, come from the creation of suitable arrangements for survival and enlargement of

  16. Analysis and Research on the Function Demand of the Prefecture-county Integrated Electricity Measuring System%电能量计量系统地县一体功能需求分析与研究

    Institute of Scientific and Technical Information of China (English)

    巫志平

    2014-01-01

    Electricity metering system is an automation system for the collection and statistics of substation power supply and demand. It not only provides real-time data for the production, operation monitoring and analysis system but also supports massive data for the forefront research on big data management and cloud computing applications. The completed power system consists of energy meter, collector, communication channels and electricity measuring main station system which is the heart of the system. The prefecture-county integrated electricity measuring system is currently promoted in the grid system. The system functional requirements is designed in the operation and maintenance mode of the prefecture-county integrated, including the web browser interface, report generation, data error correction and requirement analysis on the lack of interaction with distribution system.For this, complex needs of data processing can be adapted increasingly while system maintenance workloads can be reduced.%电能量计量系统是用来采集和统计变电站电力电量供需状况的自动化系统,不仅为生产、运营监控分析系统提供实时数据,还可以为正处于前沿研究的大数据管理、云计算应用提供海量数据支撑。完整的电能量系统由电能表、采集器、通信通道、电能量计量主站系统构成,主站系统处于核心地位。目前,电网系统内正推广建设地县一体电量系统。探讨在地县一体运行维护模式下,对系统功能需求进行设计,包括Web界面浏览、报表生成、数据纠错及与营配系统交互功能不足进行需求分析,在减轻系统维护工作量的同时适应日益复杂的数据处理需求。

  17. Eletroestimulação seletiva mantem estrutura e função do tibial anterior desnervado de ratos Structure and function of denervated tibialis anteriores are maintained by electrical stimulation in rats

    Directory of Open Access Journals (Sweden)

    Juliana de Tillio Polônio

    2010-01-01

    Full Text Available OBJETIVO: A eletroestimulação para tratamento de músculos desnervados deve ser aplicada através do tratamento seletivo. Este estudo avaliou o efeito da eletroestimulação seletiva do músculo desnervado sobre sua estrutura e função. MÉTODOS: Foram utilizados cinqüenta ratos Wistar distribuídos em controle, desnervado estimulado e desnervado não-estimulado. Após avaliação eletrodiagnóstica de estímulo pré-desnervação, os animais sofreram desnervação proximal completa do músculo tibial anterior unilateral. Houve reavaliação semanal para adaptação dos parâmetros de tratamento seletivo, aplicado três vezes por semana. Os animais foram mortos após 7, 14, 28 e 56 dias do pós-cirúrgico. Foram realizados procedimentos histoquímicos e estudos morfológicos e morfométricos. RESULTADOS: Os animais desnervados estimulados não apresentaram contratura da articulação do tornozelo e não houve automutilações nas patas. Alterações significativas nas áreas das fibras musculares tipo IIB (desnervados estimulados aos 7 dias e tipo IIA e híbridas (desnervados estimulados 28 e 56 dias indicaram menor atrofia. Transição do tipos de fibras musculares foi significativa, indicando uma manutenção do padrão funcional do músculo tibial anterior nos períodos de 7 e 14 dias. CONCLUSÃO: Conclui-se que houve manutenção temporária da estrutura e função do músculo tibial anterior desnervado através da eletroestimulação seletiva.OBJECTIVE: Electrical stimulation for treatment of denervated muscles should be implemented by selective treatment. This study evaluated the effect of selective electrical stimulation on the structure and function of denervated muscle. METHODS: Fifty Wistar mice were allocated to control, stimulated denervated and non-stimulated denervated groups. Following an electrodiagnostic evaluation, the animals underwent complete unilateral denervation of the proximal anterior tibialis muscle. Weekly re

  18. Corrosion Protection of Electrically Conductive Surfaces

    Directory of Open Access Journals (Sweden)

    Jian Song

    2012-11-01

    Full Text Available The basic function of the electrically conductive surface of electrical contacts is electrical conduction. The electrical conductivity of contact materials can be largely reduced by corrosion and in order to avoid corrosion, protective coatings must be used. Another phenomenon that leads to increasing contact resistance is fretting corrosion. Fretting corrosion is the degradation mechanism of surface material, which causes increasing contact resistance. Fretting corrosion occurs when there is a relative movement between electrical contacts with surfaces of ignoble metal. Avoiding fretting corrosion is therefore extremely challenging in electronic devices with pluggable electrical connections. Gold is one of the most commonly used noble plating materials for high performance electrical contacts because of its high corrosion resistance and its good and stable electrical behavior. The authors have investigated different ways to minimize the consumption of gold for electrical contacts and to improve the performance of gold plating. Other plating materials often used for corrosion protection of electrically conductive surfaces are tin, nickel, silver and palladium. This paper will deal with properties and new research results of different plating materials in addition to other means used for corrosion protection of electrically conductive surfaces and the testing of corrosion resistance of electrically conductive surfaces.

  19. Electric Vehicles in Imperfect Electricity Markets

    OpenAIRE

    Schill, Wolf-Peter

    2011-01-01

    We use a game-theoretic model to analyze the impacts of a hypothetical fleet of plug-in electric vehicles on the imperfectly competitive German electricity market. Electric vehicles bring both additional demand and additional storage capacity to the market. We determine the effects on prices, welfare, and electricity generation for various cases with different players in charge of vehicle operations. Vehicle loading increases generator profits, but decreases consumer surplus in the power mark...

  20. The Electric Car Challenge.

    Science.gov (United States)

    Diehl, Brian E.

    1997-01-01

    Describes the Electric Car Challenge during which students applied methods of construction to build lightweight, strong vehicles that were powered by electricity. The activity required problem solving, sheet metal work, electricity, design, and construction skills. (JOW)

  1. Agricultural Electricity. Electric Motors. Student Manual.

    Science.gov (United States)

    Benson, Robert T.

    Addressed to the student, this manual, which includes supplementary diagrams, discusses the following topics and principles: Electromagnetic fields, electromagnets, parts of an electric motor, determining speed of an electric motor, types of electric motors in common use (split-phase, capacitor, repulsion-induction, three-phase), the electric…

  2. Review on Automotive Power Generation System on Plug-in Hybrid Electric Vehicles & Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Leong Yap Wee

    2016-01-01

    Full Text Available Regenerative braking is a function to recharge power bank on the Plug-in electric vehicles (PHEV and electric vehicles (EV. The weakness of this system is, it can only perform its function when the vehicle is slowing down or by stepping the brake foot pedal. In other words, the electricity recharging system is inconsistent, non-continuous and geography dependent. To overcome the weakness of the regenerative braking system, it is suggested that to apply another generator which is going to be parallel with the regenerative braking system so that continuous charging can be achieved. Since the ironless electricity generator has a less counter electromotive force (CEMF comparing to an ironcored electricity generator and no cogging torque. Applying the ironless electricity generator parallel to the regenerative braking system is seen one of the options which creates sustainable charging system compared to cored electricity generator.

  3. DOE handbook electrical safety

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    Electrical Safety Handbook presents the Department of Energy (DOE) safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety guidance and information for DOE installations to effect a reduction or elimination of risks associated with the use of electrical energy. The objectives of this handbook are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  4. Electrical engineer's reference book

    CERN Document Server

    Laughton, M A

    1985-01-01

    Electrical Engineer's Reference Book, Fourteenth Edition focuses on electrical engineering. The book first discusses units, mathematics, and physical quantities, including the international unit system, physical properties, and electricity. The text also looks at network and control systems analysis. The book examines materials used in electrical engineering. Topics include conducting materials, superconductors, silicon, insulating materials, electrical steels, and soft irons and relay steels. The text underscores electrical metrology and instrumentation, steam-generating plants, turbines

  5. Electrical safety guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1993-09-01

    The Electrical Safety Guidelines prescribes the DOE safety standards for DOE field offices or facilities involved in the use of electrical energy. It has been prepared to provide a uniform set of electrical safety standards and guidance for DOE installations in order to affect a reduction or elimination of risks associated with the use of electrical energy. The objectives of these guidelines are to enhance electrical safety awareness and mitigate electrical hazards to employees, the public, and the environment.

  6. Electric and magnetic dipole shielding constants for the ground state of the relativistic hydrogen-like atom: Application of the Sturmian expansion of the generalized Dirac-Coulomb Green function

    CERN Document Server

    Stefańska, Patrycja

    2011-01-01

    The Sturmian expansion of the generalized Dirac-Coulomb Green function [R. Szmytkowski, J. Phys. B 30 (1997) 825; erratum 30 (1997) 2747] is exploited to derive closed-form expressions for electric ($\\sigma_{\\mathrm{E}}$) and magnetic ($\\sigma_{\\mathrm{M}}$) dipole shielding constants for the ground state of the relativistic hydrogen-like atom with a point-like and spinless nucleus of charge $Ze$. It is found that $\\sigma_{\\mathrm{E}}=Z^{-1}$ (as it should be) and $$\\sigma_{\\mathrm{M}}=-(2Z\\alpha^{2}/27)(4\\gamma_{1}^{3}+6\\gamma_{1}^{2}-7\\gamma_{1}-12) /[\\gamma_{1}(\\gamma_{1}+1)(2\\gamma_{1}-1)],$$ where $\\gamma_{1}=\\sqrt{1-(Z\\alpha)^{2}}$ ($\\alpha$ is the fine-structure constant). This expression for $\\sigma_{\\mathrm{M}}$ agrees with earlier findings of several other authors, obtained with the use of other analytical techniques, and is elementary compared to an alternative one presented recently by Cheng \\emph{et al.} [J. Chem. Phys. 130 (2009) 144102], which involves an infinite series of ratios of the Euler'...

  7. Integrating The Non-Electrical Worker Into The Electrical Safety Program

    Energy Technology Data Exchange (ETDEWEB)

    Mills, T. David; McAlhaney, John H.

    2012-08-17

    The intent of this paper is to demonstrate an electrical safety program that incorporates all workers into the program, not just the electrical workers. It is largely in response to a paper presented at the 2012 ESW by Lanny Floyd entitled "Facilitating Application of Electrical Safety Best Practices to "Other" Workers" which requested all attendees to review their electrical safety program to assure that non-electrical workers were protected as well as electrical workers. The referenced paper indicated that roughly 50% of electrical incidents involve workers whose primary function is not electrical in nature. It also encouraged all to "address electrical safety for all workers and not just workers whose job responsibilities involve working on or near energized electrical circuits." In this paper, a program which includes specific briefings to non-electrical workers as well as to workers who may need to perform their normal activities in proximity to energized electrical conductors is presented. The program uses a targeted approach to specific areas such as welding, excavating, rigging, chart reading, switching, cord and plug equipment and several other general areas to point out hazards that may exist and how to avoid them. NFPA 70E-2004 was incorporated into the program several years ago and with it the need to include the "other" workers became apparent. The site experience over the years supports the assertion that about half of the electrical incidents involve non-electrical workers and this prompted us to develop specific briefings to enhance the knowledge of the non-electrical worker regarding safe electrical practices. The promotion of "May is Electrical Safety Month" and the development of informative presentations which are delivered to the general site population as well as electrical workers have greatly improved the hazards awareness status of the general worker on site.

  8. 电刺激阴茎海绵体神经测定大鼠勃起功能的方法探讨%Measuring erectile function in rats through electrical stimulation of the cavernous nerve

    Institute of Scientific and Technical Information of China (English)

    王先进; 沈周俊; 张敏光; 钟山; 张存明; 朱照伟

    2012-01-01

    目的:探讨电刺激阴茎海绵体神经(CN)测定大鼠勃起功能的方法.方法:选择4月龄雄性SD大鼠20只,体质量(425±25)g.左颈总动脉内插管,直接法持续监测大鼠平均动脉压(MAP);左侧海绵体内插管测定阴茎海绵体内压(ICP);前列腺右侧叶前外侧表面暴露右侧CN,通过电刺激CN诱发阴茎勃起.电刺激参数为:5V,2 ms,25 Hz,每次刺激持续1 min,间隔5 min重复电刺激,共刺激3次.电刺激CN前的(ICP/MAP)×100(rR)代表阴茎海绵体的静息状态;电刺激CN后的(ICP最大值/MAP)×100(bR)代表阴茎海绵体的勃起状态或大鼠的基础勃起功能;bR/rR代表阴茎勃起后ICP的增高程度.结果:电刺激CN使ICP明显升高,MAP变化不大,表明电刺激可有效诱发勃起.ICP、MAP、rR、bR、bR/rR等各项指标3次重复测定之间的差异均无统计学意义(均P>0.05),表明电刺激法结果稳定.rR、bR和bR/rR总的平均值分别为(12.00±2.62)%、(67.68±11.28)%和(5.85±1.80).结论:电刺激阴茎CN测定大鼠勃起功能的方法稳定易重复,能够客观准确地评估阴茎的勃起程度,是研究阴茎勃起功能的重要技术,值得在国内推广.%Objective:To investigate the feasibility of measuring erectile function in rats through the electrical stimulation of the cavernous nerve(CN).Methods: Twenty 4-month-old male SD rats( weight,425 ± 25 g) were used in our study.The erectile response was expressed as a ratio of intracavernous pressure(ICP)and mean arterial pressure(MAP) ,(ICP/MAP) × 100,during electrostimulation of the right CN.The electrical-stimulation parameters were 5 V,2 ms,25 Hz,and 1 min for each stimulation and once again every 5 minutes.Before electrostimulation,the(ICP/MAP) ×100 (abbr,rR) represents resting state of penis.After electrostimulation,the(ICPmax/ MAP) × l00(abbr,bR)represents fundamentally erectile state of penis.bR/rR stands for the increased degree of ICP induced by electrostimulation

  9. Curative effect observation of electrical stimulation to cerebellar fastigial nucleus on nerve function recovery of cerebral infarction patients%电刺激小脑顶核对脑梗死患者神经功能恢复的疗效观察

    Institute of Scientific and Technical Information of China (English)

    彭昌鼎; 孙鸣; 王昌铭; 吉国泰; 姬向丽

    2002-01-01

    Objective To observe curative effect of electrical stimulation cerebellar fastigial nucleus on nerve function recovery of cerebral infarction patients.Method The patients were treated with electrical stimulation cerebellar fastigial nucleus except for routine drugs,the electrode were placed on the bilateral mastoid processes,giving pulse electric current for forty minutes two times per day,for a 10 day couse treatment.The parameter was set at model 1,frequency was 131% ~ 136% and intensity was 70% ~ 90% .Result Total effective rate of therapeutic group and control group were 91.7% and 71.4% separately.χ 2=4.860(P< 0.05).The nerver function defect score was manifestly decreased.There was a significant difference between the therapeutic group and control group,and between before and after treatment in therapeutic group(P< 0.01).Conclusion The experiment suggested that the treatment of cerebral infarction by drugs except adding electrical stimulation of cerebellar fastigial nucleus is better than by drugs along.The electrical stimulation of cerebellar fastigial nucleus has obvious protective effect.It can promote recovery of cerebral infarction.

  10. Implantable neurotechnologies: electrical stimulation and applications.

    Science.gov (United States)

    Nag, Sudip; Thakor, Nitish V

    2016-01-01

    Neural stimulation using injected electrical charge is widely used both in functional therapies and as an experimental tool for neuroscience applications. Electrical pulses can induce excitation of targeted neural pathways that aid in the treatment of neural disorders or dysfunction of the central and peripheral nervous system. In this review, we summarize the recent trends in the field of electrical stimulation for therapeutic interventions of nervous system disorders, such as for the restoration of brain, eye, ear, spinal cord, nerve and muscle function. Neural prosthetic applications are discussed, and functional electrical stimulation parameters for treating such disorders are reviewed. Important considerations for implantable packaging and enhancing device reliability are also discussed. Neural stimulators are expected to play a profound role in implantable neural devices that treat disorders and help restore functions in injured or disabled nervous system. PMID:26753775

  11. Nucleon Magnetic Moments and Electric Polarizabilities

    Energy Technology Data Exchange (ETDEWEB)

    W Detmold, B C Tiburzi, A Walker-Loud

    2010-06-01

    Electromagnetic properties of the nucleon are explored with lattice QCD using a novel technique. Focusing on background electric fields, we show how the electric polarizability can be extracted from nucleon correlation functions. A crucial step concerns addressing contributions from the magnetic moment, which affects the relativistic propagation of nucleons in electric fields. By properly handing these contributions, we can determine both magnetic moments and electric po larizabilities. Lattice results from anisotropic clover lattices are presented. Our method is not limited to the neutron; we show results for the proton as well.

  12. Electrical installations technology

    CERN Document Server

    Whitfield, J F

    1968-01-01

    Electrical Installations Technology covers the syllabus of the City and Guilds of London Institute course No. 51, the "Electricians B Certificate”. This book is composed of 15 chapters that deal with basic electrical science and electrical installations. The introductory chapters discuss the fundamentals and basic electrical principles, including the concept of mechanics, heat, magnetic fields, electric currents, power, and energy. These chapters also explore the atomic theory of electric current and the electric circuit, conductors, and insulators. The subsequent chapter focuses on the chemis

  13. Effect of gait triggered functional electrical stimulation on incomplete spinal cord injury patients%步态诱发功能性电刺激对不完全性脊髓损伤患者的疗效观察

    Institute of Scientific and Technical Information of China (English)

    谢映; 朱文新; 李玲; 吴汨霞; 张鹏程; 李洋

    2013-01-01

    Objective: To observe the effect of gait triggered functional electrical stimulation on incomplete spinal cord in-jury(SCI). Method: Forty patients with incomplete SCI after fractures of thoracolumbar segment were randomly divided into two groups: the treatment group(20cases) and the control group (20cases). Based on routine medical treatment and rehabilitation therapy, patients of treatment group received functional electrical stimulation(FES) on common perone-al nerve and tibia]is anterior muscle of affected side by using XFT-2001 10w-frequency electrical pulse stimulator, and at the same time 15-20min walking training, twice a day, 5-6d per week,4 weeks in total. Scores of FIM,10m maximum walking speed and tibialis anterior muscle motor evoked potential(MED) latency were evaluated before treatment, 2 weeks after treatment and 4 weeks after treatment. Tibialis anterior muscular strength was compared before treatment and 4 weeks after treatment. Result: After 2 weeks treatment, scores of FIM, 10m maximum walking speed and tibialis anterior muscle MEP latency in both groups had not significant difference (P> 0.05) 0 After 4 weeks treatment, It was shown that the scores of FIM and 10m maximum walking speed increased after treatment(P<0.01, P<0.05), tibialis anterior muscle latency shortened (P<0.01), tibialis anterior muscular strength enhanced (P<0.05) compared with control group. Conclusion: FES could improve walking function of incomplete SCI patient. MEP examination could provide objective and quantitative basis for judging the motor functional status of spinal cord. FES was considered to be a safe and effective training method.%目的:观察步态诱发功能性电刺激治疗不完全性脊髓损伤患者的疗效.方法:对40例不完全性脊髓损伤的患者,随机分为两组,对照组进行常规药物治疗、康复治疗,治疗组除常规药物治疗、康复治疗,每天佩戴步态诱发功能性电刺激进行患侧腓总神经、胫前

  14. Functional materials

    International Nuclear Information System (INIS)

    It is a compilation of chapters written by active researchers and offer information and critical insights about semiconducting materials and devices, dielectric and ferroelectric materials, magnetic materials, composites and other functional materials. In the book, the functional materials are discussed from the mixed valences and stoichiometry points of view, to understand the structural evolution and transformation of different material systems - in particular, the role played by crystal structures in property control of functional materials using advanced characterization techniques. The book examines the properties, soft-chemistry preparations, electronic structures and crystal structures of transition and rare earth metals and their oxides. The book presents a strong argument that functional materials system is the future direction of the multidisciplinary research involving physics, chemistry, materials science and electrical engineering, with emphasis on device applications. Papers relevant to INIS are indexed separately

  15. Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits%功能性电刺激恢复周围性面神经麻痹兔眨眼功能的研究

    Institute of Scientific and Technical Information of China (English)

    薛玉斌; 冯国栋; 丁秀勇; 赵杨; 崔婷婷; 高志强

    2014-01-01

    兔的双侧同步眨眼.%Objective Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink,and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP).Methods Firstly,twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups,who received square,sine and triangle pulse wareforms,respectirely.Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes.For each rabbit,twenty-seven combinations of frequencies (25 Hz,50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated.The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters.Secondly,a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits,it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle,and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG.Results When the carrier frequency of the pulse train was 25 Hz,it was not able to induce a smooth blink.However,when the carrier frequencies were 50 Hz and 100 Hz,a smooth blink could be induced.The voltage required by 100 Hz was lower than 50 Hz,but it cost more electric charge.The amplitude that square waveforms required was far lower than sine and triangle,but the electric charge between the three waveforms was similar.Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system.Conclusions To elicit a blink,square pulse train delivered in 50 Hz is a preferable option.The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.

  16. Point Electric Stimulation and Children's Amblyopia

    Institute of Scientific and Technical Information of China (English)

    YAN Xing-ke; CHU Hui-ju; WANG Fu-chun; YANG Bo; GAO Yang; HAN Chou-ping

    2007-01-01

    To observe the therapeutic efficacy of electric stimulation on points for children's amblyopia.Method:Ninety children amblyopia cases with ametropia upon correction were randomized into three groups:point electric stimulation,comprehensive conventional therapy and integrative therapy of the above two.And then visual function changes of kids in the three groups were observed.Results:Among the above three therapies,the recovery rates of point electric stimulation,comprehensive conventional therapy and integrative therapy of the two were 83.9%,82.6%and 94.25 respectively,showing no significant difierence(P>0.05) among the three groups.Conclusion:Point electric stimulation has similar action with comprehensive conventional therapy in the treatment of children's amblyopia,and the combination of the two therapies has better effect,indicating point electric stimulation can speed up recovery of visual function of kids with amblyopia.

  17. External costs of electricity

    International Nuclear Information System (INIS)

    This article presents a synthesis of the ExternE project (External costs of Energy) of the European community about the external costs of power generation. Pollution impacts are calculated using an 'impact pathways' analysis, i.e. an analysis of the emission - dispersion - dose-response function - cost evaluation chain. Results are presented for different fuel cycles (with several technological variants) with their confidence intervals. The environmental impact costs are particularly high for coal: for instance, in France, for coal-fired power plants it is of the same order as the electricity retail price. For natural gas, this cost is about a third of the one for coal. On the contrary, the environmental impact costs for nuclear and renewable energies are low, typically of few per cent of the electricity price. The main part of these costs corresponds to the sanitary impacts, in particular the untimely mortality. In order to avoid any controversy about the cost evaluation of mortality, the reduction of the expectation of life due to the different fuel cycles is also indicated and the risks linked with nuclear energy are presented using several comparisons. (J.S.)

  18. The Nordic financial electricity market

    Energy Technology Data Exchange (ETDEWEB)

    2010-11-15

    NordREG is a cooperation of the Nordic energy regulators. The mission is to actively promote legal and institutional framework and conditions necessary for developing the Nordic and European electricity markets. The financial market is an important market for market participants to mitigate their risks. By providing tools for risk management, the financial market contributes to the efficient functioning of both wholesale and end-user markets. NordREG decided during 2009 to undertake a study on the Nordic financial electricity market. The aim of the report is to consider whether any improvements can be made to further increase the efficiency of the Nordic financial electricity market in order to secure an optimal price setting in the wholesale and the end-user markets

  19. Electrical breakdown in tissue electroporation.

    Science.gov (United States)

    Guenther, Enric; Klein, Nina; Mikus, Paul; Stehling, Michael K; Rubinsky, Boris

    2015-11-27

    Electroporation, the permeabilization of the cell membrane by brief, high electric fields, has become an important technology in medicine for diverse application ranging from gene transfection to tissue ablation. There is ample anecdotal evidence that the clinical application of electroporation is often associated with loud sounds and extremely high currents that exceed the devices design limit after which the devices cease to function. The goal of this paper is to elucidate and quantify the biophysical and biochemical basis for this phenomenon. Using an experimental design that includes clinical data, a tissue phantom, sound, optical, ultrasound and MRI measurements, we show that the phenomenon is caused by electrical breakdown across ionized electrolysis produced gases near the electrodes. The breakdown occurs primarily near the cathode. Electrical breakdown during electroporation is a biophysical phenomenon of substantial importance to the outcome of clinical applications. It was ignored, until now.

  20. Electric circuit theory applied electricity and electronics

    CERN Document Server

    Yorke, R

    1981-01-01

    Electric Circuit Theory provides a concise coverage of the framework of electrical engineering. Comprised of six chapters, this book emphasizes the physical process of electrical engineering rather than abstract mathematics. Chapter 1 deals with files, circuits, and parameters, while Chapter 2 covers the natural and forced response of simple circuit. Chapter 3 talks about the sinusoidal steady state, and Chapter 4 discusses the circuit analysis. The fifth chapter tackles frequency response of networks, and the last chapter covers polyphase systems. This book will be of great help to electrical

  1. Os efeitos da estimulação elétrica funcional na assimetria cortical inter-hemisférica The effects of functional electrical stimulation on cortical interhemispheric asymmetry

    Directory of Open Access Journals (Sweden)

    Letícia Ecard

    2007-09-01

    Full Text Available O objetivo do presente estudo foi avaliar os efeitos da estimulação elétrica funcional na assimetria cortical inter-hemisférica. Para tal, simultaneamente ao registro da atividade eletroencefalográfica, realizou-se eletroestimulação no antebraço direito para estimulação da extensão do indicador. A amostra consistiu de 45 sujeitos randomizados em 3 grupos de 15 sujeitos cada: grupo controle (submetido a 24 blocos de estimulação com intensidade de corrente zero, grupo 1 (24 blocos e grupo 2 (36 blocos. A assimetria entre os pares de eletrodos F3-F4, C3-C4 e P3-P4 foi analisada ao longo dos grupos através de uma Anova. Os resultados apontaram para uma interação grupo x eletrodo e uma tendência de diminuição da assimetria inter-hemisférica após a eletroestimulação.The aim of the present study was to assess the effects of functional electrical stimulation (FES on cortical interhemispheric asymmetry. Electrostimulation was performed on the right forearm to stimulate the extension of the index finger. EEG activity was recorded simultaneously. The sample included 45 subjects randomly divided into 3 groups of 15 subjects each: control group (submitted to 24 blocks of stimulation at a null intensity current, group 1 (24 blocks and group 2 (36 blocks. Interhemispheric asymmetry between F3-F4, C3-C4 and P3-P4 was analyzed through an Anova. Results pointed out to a group x electrode interaction and a general tendency of asymmetry decrease after stimulation.

  2. Alterações na coerência cortical inter-hemisférica produzidas pela estimulação elétrica funcional (FES Changes in cortical interhemispheric coherence produced by functional electrical stimulation (FES

    Directory of Open Access Journals (Sweden)

    Letícia Ecard

    2007-06-01

    Full Text Available O presente estudo teve como objetivo observar alterações corticais produzidas pela estimulação elétrica funcional (FES, através da eletrencefalografia quantitativa (EEGq. Simultaneamente à captação do sinal eletrencefalográfico, realizou-se uma eletroestimulação no antebraço direito para estimulaç��o da extensão do indicador. A amostra consistiu de 45 sujeitos randomizados em 3 grupos de 15. O grupo controle foi submetido a 24 blocos de estimulação com intensidade de corrente zero. O grupo 1 foi submetido a 24 blocos e o grupo 2 a 36 blocos. A coerência entre os pares de eletrodos F3-F4, C3-C4 e P3-P4 foi analisada ao longo dos grupos através de avaliação estatística. Os resultados apontaram para um aumento da coerência inter-hemisférica após a eletroestimulação.The aim of the present study was to observe cortical alterations produced by functional electrical stimulation (FES, through quantitative electroencephalography (qEEG. Electrostimulation was performed on the right forearm to stimulate the extension of the index finger. EEG activity was recorded simultaneously. The sample consisted of 45 subjects randomly divided into 3 groups of 15 subjects each. The control group was submitted to 24 blocks of stimulation at a current intensity of zero. Group 1 was submitted to 24 blocks and group 2 to 36 blocks. Interhemispheric coherence between F3-F4, C3-C4 and P3-P4 was assessed through a statistical analysis. Results pointed out to increased coherence values after stimulation.

  3. Topics on electricity trade

    International Nuclear Information System (INIS)

    being unable to fulfil the commitments made on the spot market. The disclosed cost of using the regulating power market is a quadratic function of the amount of regulation. This asymmetric cost may encourage bidders with fluctuating production to be more strategic in their way of bidding on the spot market. By using such strategies the extra costs (for e.g. wind power) needed to counter unpredictable fluctuations may be limited. The fourth paper applies the findings in the previous paper to show how a supplier with a 'controllable' production will make strategic bids on the power exchange - in this case a heat pump. The fifth paper discusses the design of the regulating power market and what the choice of design means for suppliers with fluctuating production, e.g. wind turbines. It is found that not only does the accuracy of the wind prediction influence the use of the power exchange, but the structure of the power exchange itself may also play an important role. Several studies of the northern European electricity liberalisation have concluded that developments of a liberalised electricity market and cross border trade can be of benefit for the consumers and bring along a global environmental improvement. All these studies have assumed that a perfect competitive electricity market can be obtained. A number of imperfections, which inevitably will arise, have not been taken into account, - at least in the transition period. These imperfections can be technical, economic or tradition-bound, but may have political characteristics as well. The sixth paper in this thesis surveys those market imperfections which are most likely to appear. Market imperfections can, for example, have structural or political characteristics that imply non-optimal competitive behaviour, e.g., the means to achieve political goals may hinder the desirable effects of the liberalisation. This can, for example, come from the creation of suitable arrangements for survival and enlargement of renewable

  4. Topics on electricity trade

    Energy Technology Data Exchange (ETDEWEB)

    Skytte, K.

    2001-07-01

    being unable to fulfil the commitments made on the spot market. The disclosed cost of using the regulating power market is a quadratic function of the amount of regulation. This asymmetric cost may encourage bidders with fluctuating production to be more strategic in their way of bidding on the spot market. By using such strategies the extra costs (for e.g. wind power) needed to counter unpredictable fluctuations may be limited. The fourth paper applies the findings in the previous paper to show how a supplier with a 'controllable' production will make strategic bids on the power exchange - in this case a heat pump. The fifth paper discusses the design of the regulating power market and what the choice of design means for suppliers with fluctuating production, e.g. wind turbines. It is found that not only does the accuracy of the wind prediction influence the use of the power exchange, but the structure of the power exchange itself may also play an important role. Several studies of the northern European electricity liberalisation have concluded that developments of a liberalised electricity market and cross border trade can be of benefit for the consumers and bring along a global environmental improvement. All these studies have assumed that a perfect competitive electricity market can be obtained. A number of imperfections, which inevitably will arise, have not been taken into account, - at least in the transition period. These imperfections can be technical, economic or tradition-bound, but may have political characteristics as well. The sixth paper in this thesis surveys those market imperfections which are most likely to appear. Market imperfections can, for example, have structural or political characteristics that imply non-optimal competitive behaviour, e.g., the means to achieve political goals may hinder the desirable effects of the liberalisation. This can, for example, come from the creation of suitable arrangements for survival and enlargement of

  5. Electricity market 2001

    International Nuclear Information System (INIS)

    The electricity markets in the Nordic countries have undergone major changes since the electricity market reform work was started in the early 1990s. Sweden, Norway and Finland have had a common electricity market since 1996. The work of also reforming the Danish electricity market was begun in the year 2000. The objective of the electricity market reform is to introduce increased competition, to give the consumers greater freedom of choice and also, by open and expanded trade in electricity, create the conditions for efficient pricing. The Swedish National Energy Administration is the supervisory authority as specified in the Electricity Act, and one of the tasks entrusted to it by the Government is to follow developments on the electricity market and to regularly compile and report current market information. The purpose of the 'Electricity market 2001' publication is to meet the need for generalized and readily accessible information on the conditions on the Nordic market. Iceland is not included in the description. The publication also includes summaries of information from recent years concerning electricity generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective, trade in electricity in the Nordic countries and in Northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment. The publication contains data on electricity generation and use during the past years, structure of the electricity market, trade in electricity in the Nordic countries and northern Europe, electricity prices in the Nordic countries and other countries as well as impact of electricity generation system on the environment

  6. Electricity market 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    The electricity markets in the Nordic countries have undergone major changes since the electricity market reform work was started in the early 1990s. Sweden, Norway and Finland have had a common electricity market since 1996. The work of also reforming the Danish electricity market was begun in the year 2000. The objective of the electricity market reform is to introduce increased competition, to give the consumers greater freedom of choice and also, by open and expanded trade in electricity, create the conditions for efficient pricing. The Swedish National Energy Administration is the supervisory authority as specified in the Electricity Act, and one of the tasks entrusted to it by the Government is to follow developments on the electricity market and to regularly compile and report current market information. The purpose of the 'Electricity market 2001' publication is to meet the need for generalized and readily accessible information on the conditions on the Nordic market. Iceland is not included in the description. The publication also includes summaries of information from recent years concerning electricity generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective, trade in electricity in the Nordic countries and in Northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment. The publication contains data on electricity generation and use during the past years, structure of the electricity market, trade in electricity in the Nordic countries and northern Europe, electricity prices in the Nordic countries and other countries as well as impact of electricity generation system on the environment.

  7. [Chemical and electrical burns].

    Science.gov (United States)

    Sanchez, Raymond

    2002-12-15

    Chemical burns are less frequent in routine practice, but could be very serious owing to the complexity and severity of their actions. Influx of casualty after a civil disaster (industrial explosion) or military (war or terrorism) is possible. The action of these agents could be prolonged and deep. In addition to the skin, respiratory lesions and general intoxication could be observed. The urgent local treatment rely essentially on prolonged washing. Prevention and adequate emergency care could limit the serious consequences of these accidents. Accidents (thermal burns or electrisations) due to high or low voltage electricity are frequent. The severity is linked with the affected skin but especially with internal lesions, muscular, neurological or cardiac lesions. All cases of electrisation need hospital care. Locally, the lesions are often deep with difficult surgical repairs and often require amputation. Aesthetic and functional sequela are therefore frequent. Secondary complications could appear several months after the accident: cataract, dysesthesia and hypotonia. PMID:12621941

  8. Hemichannel composition and electrical synaptic transmission: molecular diversity and its implications for electrical rectification.

    Science.gov (United States)

    Palacios-Prado, Nicolás; Huetteroth, Wolf; Pereda, Alberto E

    2014-01-01

    Unapposed hemichannels (HCs) formed by hexamers of gap junction proteins are now known to be involved in various cellular processes under both physiological and pathological conditions. On the other hand, less is known regarding how differences in the molecular composition of HCs impact electrical synaptic transmission between neurons when they form intercellular heterotypic gap junctions (GJs). Here we review data indicating that molecular differences between apposed HCs at electrical synapses are generally associated with rectification of electrical transmission. Furthermore, this association has been observed at both innexin and connexin (Cx) based electrical synapses. We discuss the possible molecular mechanisms underlying electrical rectification, as well as the potential contribution of intracellular soluble factors to this phenomenon. We conclude that asymmetries in molecular composition and sensitivity to cellular factors of each contributing hemichannel can profoundly influence the transmission of electrical signals, endowing electrical synapses with more complex functional properties.

  9. Electrical conductivity of chondritic meteorites

    Science.gov (United States)

    Duba, AL; Didwall, E. M.; Burke, G. J.; Sonett, C. P.

    1987-01-01

    The electrical conductivity of samples of the Murchison and Allende carbonaceous chondrites is 4 to 6 orders of magnitude greater than rock forming minerals such as olivine for temperatures up to 700 C. The remarkably high electrical conductivity of these meteorites is attributed to carbon at the grain boundaries. Much of this carbon is produced by pyrolyzation of hydrocarbons at temperatures in excess of 150 C. As the temperature increases, light hydrocarbons are driven off and a carbon-rich residue or char migrates to the grain boundaries enhancing electrical conductivity. Assuming that carbon was present at the grain boundaries in the material which comprised the meteorite parent bodies, the electrical heating of such bodies was calculated as a function of body size and solar distance during a hypothetical T-Tauri phase of the sun. Input conductivity data for the meteorite parent body were the present carbonaceous chondrite values for temperatures up to 840 C and the electrical conductivity values for olivine above 840 C.

  10. Electrical machines diagnosis

    CERN Document Server

    Trigeassou, Jean-Claude

    2013-01-01

    Monitoring and diagnosis of electrical machine faults is a scientific and economic issue which is motivated by objectives for reliability and serviceability in electrical drives.This book provides a survey of the techniques used to detect the faults occurring in electrical drives: electrical, thermal and mechanical faults of the electrical machine, faults of the static converter and faults of the energy storage unit.Diagnosis of faults occurring in electrical drives is an essential part of a global monitoring system used to improve reliability and serviceability. This diagnosis is perf

  11. Electrical installation calculations advanced

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for advanced electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practiceA step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3For apprentices and electrical installatio

  12. 功能性电刺激结合智能运动对脑卒中偏瘫患者运动功能的影响%Functional electrical stimulation combined with intelligent motion effects on motor function of hemiplegic pa-tients with cerebral infarction

    Institute of Scientific and Technical Information of China (English)

    耿尚勇; 李月春; 李峰

    2014-01-01

    目的:应用功能性电刺激结合智能运动治疗脑卒中偏瘫患者,并观察其疗效,探讨脑卒中患者康复治疗的新方法。方法入选我院神经科经头颅C T或头颅M RI检查证实的脑卒中偏瘫患者110例,随机分为4组,所有患者均给予神经内科常规治疗及基础康复。A组加用功能性电刺激仪智能运动进行同步智能运动训炼;B组单用功能性电刺激,C组单用智能运动系统进行肢体运动,D组常规康复治疗。康复6周,治疗前后采用 Fugl-Meyer运动功能量表(FMA)、Berg平衡量表(BBS)、Barthel指数评定(BI)进行评定。结果4组治疗后FMA、BBS、BI评分比较差异均有统计学意义(P<0.05);治疗后A组评分与其他3组相比,差异有统计学意义(P<0.05),说明A组功能改善最显著;B组、C组治疗后与D组相比差异有统计学意义(P<0.05),说明B组、C组治疗较D组有效,功能改善较D组明显,但治疗后B组、C组组间对比差异无统计学意义( P>0.05)。结论在基础康复治疗上进行功能性电刺激结合智能运动系统训练,对脑卒中患者偏瘫会产生积极影响,对患者上下肢运动功能,平衡能力,均有积极改善作用,最终改善了脑卒中偏瘫患者的日常生活能力,提高患者生存和生活质量,明显优于单纯基础康复及基础康复加功能性电刺激或单纯智能运动,为脑卒中偏瘫患者康复提供了新方法。%Objective To observe the efficacy of functional electrical stimulation combined with intelligent motion on motor function of hemiplegic patients with cerebral infarction , and to explore new methods for rehabilitation in stroke pa-tients.Methods One hundred and ten cerebral apoplexy patients with hemiplegia confirmed by CT or head MRI admitted to our hospital had been chosen and divided into 4 groups ,who were all given general treatment and infrastructure rehabilitation

  13. Electricity market 2000

    International Nuclear Information System (INIS)

    The electricity markets in the Nordic countries have undergone major changes since the electricity market reform work was started in the early 1990s. Sweden, Norway and Finland have a common electricity market since 1996.The work of also reforming the Danish electricity market was begun in the year 2000. The objective of the electricity market reform is to introduce increased competition,to give the consumers greater freedom of choice and also, by open and expanded trade in electricity, create the conditions for efficient pricing. The Swedish National Energy Administration is the supervisory authority as specified in the Electricity Act, and one of the tasks entrusted to it by the Government is to follow developments on the electricity market and to regularly compile and report current market information. The purpose of the present publication is to meet the need for generalized and readily accessible information on the conditions on the Nordic markets.The publication includes summaries of information from recent years concerning electricity generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective trade in electricity in the Nordic countries and in Northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment

  14. Electricity market 2000

    Energy Technology Data Exchange (ETDEWEB)

    Korsfeldt, T.; Petsala, B.

    2000-08-01

    The electricity markets in the Nordic countries have undergone major changes since the electricity market reform work was started in the early 1990s. Sweden, Norway and Finland have a common electricity market since 1996.The work of also reforming the Danish electricity market was begun in the year 2000. The objective of the electricity market reform is to introduce increased competition,to give the consumers greater freedom of choice and also, by open and expanded trade in electricity, create the conditions for efficient pricing. The Swedish National Energy Administration is the supervisory authority as specified in the Electricity Act, and one of the tasks entrusted to it by the Government is to follow developments on the electricity market and to regularly compile and report current market information. The purpose of the present publication is to meet the need for generalized and readily accessible information on the conditions on the Nordic markets.The publication includes summaries of information from recent years concerning electricity generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective trade in electricity in the Nordic countries and in Northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment.

  15. Identification of potential locations of electric vehicle supply equipment

    Science.gov (United States)

    Brooker, R. Paul; Qin, Nan

    2015-12-01

    Proper placement of electric vehicle supply equipment (charging stations) requires an understanding of vehicle usage patterns. Using data from the National Household Travel Survey on vehicle mileage and destination patterns, analyses were performed to determine electric vehicles' charging needs, as a function of battery size and state of charge. This paper compares electric vehicle charging needs with Department of Energy electric vehicle charging data from real-world charging infrastructure. By combining the electric vehicles charging needs with charging data from real-world applications, locations with high electric vehicle charging likelihood are identified.

  16. Thermal fatigue of electrical fuses

    OpenAIRE

    Gelet Jean-Louis

    2014-01-01

    Electric Fuses have to respect different national or international standards such as IEC (International Electro-technical Commission) 269. These standards define the characteristics of the fuses and describe the tests to be run in order to check fuse's ability to take up their main functions, i.e. current-conduction and operation under overloads and short-circuits. But fuses never carry current neither operate under standardized conditions. For example, rated current is evaluated under specif...

  17. Electricity and Man (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Asimov, Isaac

    1974-01-01

    Our whole industrial civilization depends upon cheap energy streaking out in all directions and under fingertip controls—and that would be very difficult without electric current. It would take enormous ingenuity to find substitutes. If all electricity were shut off, then all electronic devices would be dead. Electric lights would darken. Aluminum would become a rare metal. All factories would have to develop power sources on the spot and would have to switch to primitive, mechanical controls. Every house and every farm would have to give up items we have come to take for granted—not only electric lights, but electric irons, electric toasters, electric water pumps, electric control of furnaces, and so on.

  18. Microreactors with Electrical Fields

    NARCIS (Netherlands)

    Agiral, Anil; Gardeniers, Han J.G.E.

    2010-01-01

    The use of electric fields in chemistry is considered an important concept of process intensification. The combination of electricity with chemistry becomes particularly valuable at smaller scales, as they are exploited in microreaction technology. Microreactor systems with integrated electrodes pro

  19. Polymers for electricity and electronics materials, properties, and applications

    CERN Document Server

    Drobny, Jiri George

    2011-01-01

    The comprehensive, practical book that explores the principles, properties, and applications of electrical polymers The electrical properties of polymers present almost limitless possibilities for industrial research and development, and this book provides an in-depth look at these remarkable molecules. In addition to traditional applications in insulating materials, wires, and cables, electrical polymers are increasingly being used in a range of emerging technologies. Presenting a comprehensive overview of how electrical polymers function and how they can be applied in the elec

  20. 基于正常行走模式的功能性电刺激对脑卒中恢复期患者行走功能的影响%Effects of functional electrical stimulation based on normal gait pattern on walking function in subjects with recovery of stroke

    Institute of Scientific and Technical Information of China (English)

    谭志梅; 姜文文; 燕铁斌; 吴伟; 宋荣

    2016-01-01

    目的 观察基于正常行走模式的功能性电刺激(FES)对脑卒中恢复期患者行走功能的影响.方法 选取2010年12月至2013年1月,在中山大学孙逸仙纪念医院及广东省中医院康复科住院的脑卒中患者,将符合入选标准的58例脑卒中恢复期患者分层后,应用Minimize计算机软件按2∶1∶1随机分为四通道FES组(n=29)、单通道FES组(n=15)、安慰电刺激组(n=14).3组患者常规治疗相同,四通道组给予基于正常行走模式的四通道FES治疗,单通道组给予单通道FES治疗,安慰电刺激组电刺激治疗与四通道组相同,但治疗时无电流输出.治疗每天1次,每次30 min,每周5次,共3周.患者分别在治疗前、治疗3周后接受下列评定:Fugl-Meyer运动评定中的下肢部分(FMA)、Berg平衡量表(BBS)、10m步行速度、表面肌电图检测步行中下肢主动肌/拮抗肌协同收缩率(CI)、改良Barthel指数(MBI).结果 治疗3周后,四通道组FMA、BBS、10 m步行速度分别由治疗前(23.0±2.2)、(31±71)和(0.23±0.10)分提高至(28.4±1.5)、(42±6)和(0.43±0.09)分;单通道组分别由治疗前(21.9±3.4)、(31±6)和(0.24±0.09)分提高至(26.6±1.8)、(38±5)和(0.34±0.08)分,安慰电刺激组分别由治疗前(23.6±3.0)、(33±5)和(0.25±0.09)分提高至(26.0±2.4)、(36±4)和(0.29±0.08)分,3组患者的FMA、BBS、10 m步行速度评分较治疗前均明显提高(P<0.05),且四通道组评分明显高于单通道组和安慰电刺激组(P<0.05).3组的MBI评分也明显提高,但组间比较未见明显差异(P>0.05).表面肌电图检测发现,3组患者患侧股四头肌/腘绳肌的CI均明显下降,与单通道组和安慰电刺激组比较,四通道组的CI下降幅度尤为明显(P<0.05).结论 基于正常行走模式的FES可显著改善脑卒中恢复期患者下肢的行走功能.%Objective To observe the effects of functional electrical stimulation (FES) based on normal gait pattern on walking function

  1. Institutionalising Green Electricity

    OpenAIRE

    Hofman, P

    2004-01-01

    Both energy companies and consumers have embraced green electricity as a concept in which electricity produced by renewable energy sources is separately marketed and priced from conventionally generated electricity based on fossil or nuclear sources. After its introduction in 1995 by an energy distributor at the end of 2003 around 35 % (2.4 million) of Dutch households were buying green electricity, and more than twenty providers of varieties of the product had emerged. From the perspective o...

  2. Electrical installation calculations

    CERN Document Server

    Watkins, AJ

    2006-01-01

    Designed to provide a step by step guide to successful application of the electrical installation calculations required in day to day electrical engineering practice, the Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike.Now in its seventh edition, Volume 1 has been fully updated to meet the requirements of the 2330 Level 2 Certificate in Electrotechnical Technology from City & Guilds, and will also prove a vi

  3. Electric Field Imaging Project

    Science.gov (United States)

    Wilcutt, Terrence; Hughitt, Brian; Burke, Eric; Generazio, Edward

    2016-01-01

    NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields. This work is intended to bring electrostatic imaging to the forefront of new inspection technologies, and new technologies in general. The specific goals are to specify the electric potential and electric field including the electric field spatial components emanating from, to, and throughout volumes containing objects or in free space.

  4. Schneider Electric sozdajot set

    Index Scriptorium Estoniae

    2003-01-01

    Maailma juhtiv elektriseadmete müüja Schneider Electric ühendab oma ettevõtted Balti- ja Põhjamaades uude divisjoni, mille nimeks saab Schneider Nordic Baltic. Eestis luuakse AS Schneider Electric Eesti, mis seni tegutses AS-i Lexel Electric nime all

  5. Electric glass capturing markets

    Energy Technology Data Exchange (ETDEWEB)

    Wikman, K.; Wikstroem, T.

    1996-11-01

    Electric glass has found its place on the construction market. In public buildings, electrically heatable windows are becoming the leading option for large glass walls. Studies on detached houses, both new and renovated, show that floor heating combined with electrically heatable windowpanes is the best choice with respect to resident`s comfort. (orig.)

  6. Electric Vehicle Technician

    Science.gov (United States)

    Moore, Pam

    2011-01-01

    With President Obama's goal to have one million electric vehicles (EV) on the road by 2015, the electric vehicle technician should have a promising and busy future. "The job force in the car industry is ramping up for a revitalized green car industry," according to Greencareersguide.com. An electric vehicle technician will safely troubleshoot and…

  7. Electric field analysis

    CERN Document Server

    Chakravorti, Sivaji

    2015-01-01

    This book prepares newcomers to dive into the realm of electric field analysis. The book details why one should perform electric field analysis and what are its practical implications. It emphasizes both the fundamentals and modern computational methods of electric machines. The book covers practical applications of the numerical methods in high voltage equipment, including transmission lines, power transformers, cables, and gas insulated systems.

  8. The electricity market 2003

    International Nuclear Information System (INIS)

    The electricity markets in the Nordic countries have undergone major changes since the electricity market reform work was started in the early 1990s. We now have a common Nordic electricity market that includes all of the Nordic countries, with the exception of Iceland. The objective of the electricity market reform is to introduce increased competition, to give consumers greater freedom of choice and also, by open and increased trade in electricity, create the conditions for efficient pricing. The Swedish Energy Agency is the supervisory authority specified in the Electricity Act, and one of the tasks entrusted to it by the Government is to follow developments on the electricity market and regularly compile and report current market information. The purpose of 'The Electricity Market 2003' publication is to meet the need for generalized and easily accessible information on the conditions on the Nordic market. The publication also includes summaries of the information from recent years concerning power generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective, trade in electricity in the Nordic countries and in northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment

  9. Electric Current Solves Mazes

    Science.gov (United States)

    Ayrinhac, Simon

    2014-01-01

    We present in this work a demonstration of the maze-solving problem with electricity. Electric current flowing in a maze as a printed circuit produces Joule heating and the right way is instantaneously revealed with infrared thermal imaging. The basic properties of electric current can be discussed in this context, with this challenging question:…

  10. Future Electricity Markets

    DEFF Research Database (Denmark)

    Pinson, Pierre

    2015-01-01

    The changing face of energy production in Europe necessitates a rethink in the way that electricity markets are structured. The ‘5s’ (Future Electricity Markets) project is a multi-disciplinary project that is looking to challenge the current approach to the design and operation of electricity...

  11. Institutionalising Green Electricity

    NARCIS (Netherlands)

    Hofman, P.

    2004-01-01

    Both energy companies and consumers have embraced green electricity as a concept in which electricity produced by renewable energy sources is separately marketed and priced from conventionally generated electricity based on fossil or nuclear sources. After its introduction in 1995 by an energy distr

  12. 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.

  13. Electricity as Transportation ``Fuel''

    Science.gov (United States)

    Tamor, Michael

    2013-04-01

    The personal automobile is a surprisingly efficient device, but its place in a sustainable transportation future hinges on its ability use a sustainable fuel. While electricity is widely expected to be such a ``fuel,'' the viability of electric vehicles rests on the validity of three assumptions. First, that the emissions from generation will be significantly lower than those from competing chemical fuels whether `renewable' or fossil. Second, that advances in battery technology will deliver adequate range and durability at an affordable cost. Third, that most customers will accept any functional limitations intrinsic to electrochemical energy storage. While the first two are subjects of active research and vigorous policy debate, the third is treated virtually as a given. Popular statements to the effect that ``because 70% of all daily travel is accomplished in less than 100 miles, mass deployment of 100 mile EVs will electrify 70% of all travel'' are based on collections of one-day travel reports such as the National Household Travel Survey, and so effectively ignore the complexities of individual needs. We have analyzed the day-to-day variations of individual vehicle usage in multiple regions and draw very different conclusions. Most significant is that limited EV range results in a level of inconvenience that is likely to be unacceptable to the vast majority of vehicle owners, and for those who would accept that inconvenience, battery costs must be absurdly low to achieve any economic payback. In contrast, the plug-in hybrid (PHEV) does not suffer range limitations and delivers economic payback for most users at realistic battery costs. More importantly, these findings appear to be universal in developed nations, with labor market population density being a powerful predictor of personal vehicle usage. This ``scalable city'' hypothesis may prove to a powerful predictor of the evolution of transportation in the large cities of the developing world.

  14. Electrical installation calculations basic

    CERN Document Server

    Kitcher, Christopher

    2013-01-01

    All the essential calculations required for basic electrical installation workThe Electrical Installation Calculations series has proved an invaluable reference for over forty years, for both apprentices and professional electrical installation engineers alike. The book provides a step-by-step guide to the successful application of electrical installation calculations required in day-to-day electrical engineering practice. A step-by-step guide to everyday calculations used on the job An essential aid to the City & Guilds certificates at Levels 2 and 3Fo

  15. Managing electrical safety

    CERN Document Server

    Wiggins, James H, Jr

    2001-01-01

    Managing Electrical Safety provides an overview of electric basics, hazards, and established standards that enables you to understand the hazards you are likely to encounter in your workplace. Focusing on typical industrial environments-which utilize voltages much higher than household or office circuits-the author identifies the eight key components of an electrical safety program and examines each using a model safety management process. You'll learn how to identify electrical hazards, how to prescribe necessary electrical Personal Protective Equipment, how to ensure that equipment is de-ene

  16. Electricity information 2012

    CERN Document Server

    2012-01-01

    Electricity Information provides a comprehensive review of historical and current market trends in the OECD electricity sector, including 2011 preliminary data. An Introduction, notes, definitions and auxiliary information are provided in Part I. Part II of the publication provides an overview of the world electricity developments in 2010 covering world electricity and heat production, input fuel mix, supply and consumption, and electricity imports and exports. A greater focus is given to the 34 OECD countries with more detailed information covering production, installed capacity, input energy

  17. Pragmatic electrical engineering fundamentals

    CERN Document Server

    Eccles, William

    2011-01-01

    Pragmatic Electrical Engineering: Fundamentals introduces the fundamentals of the energy-delivery part of electrical systems. It begins with a study of basic electrical circuits and then focuses on electrical power. Three-phase power systems, transformers, induction motors, and magnetics are the major topics.All of the material in the text is illustrated with completely-worked examples to guide the student to a better understanding of the topics. This short lecture book will be of use at any level of engineering, not just electrical. Its goal is to provide the practicing engineer with a practi

  18. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  19. Quantum, Photo-Electric Single Capacitor Paradox

    CERN Document Server

    Kapor, Darko

    2009-01-01

    In this work single capacitor paradox (a variation of the remarkable two capacitor paradox) is considered in a new, quantum discrete form. Simply speaking we consider well-known usual, photoelectric effect experimental device, i.e. photo electric cell, where cathode and anode are equivalently charged but non-connected. It, obviously, represents a capacitor that initially, i.e. before action of the photons with individual energy equivalent to work function, holds corresponding energy of the electrical fields between cathode and anode. Further, we direct quantum discretely photons, one by one, toward cathode where according to photo-electrical effect electrons discretely, one by one, will be emitted and directed toward anode. It causes discrete discharge of the cell, i.e. capacitor and discrete decrease of the electrical field. Finally, total discharge of the cell, i.e. capacitor, and total disappearance of the electrical field and its energy will occur. Given, seemingly paradoxical, capacitor total energy loss...

  20. Cortical excitability changes following grasping exercise augmented with electrical stimulation

    DEFF Research Database (Denmark)

    Barsi, Gergely Istvan; Popovic, Dejan B.; Tarkka, Ina M.;

    2008-01-01

    Rehabilitation with augmented electrical stimulation can enhance functional recovery after stroke, and cortical plasticity may play a role in this process. The purpose of this study was to compare the effects of three training paradigms on cortical excitability in healthy subjects. Cortical......) functional electrical stimulation (FES) of the finger flexors and extensors, (2) voluntary movement (VOL) with sensory stimulation, and (3) therapeutic FES (TFES) where the electrical stimulation augmented voluntary activation. TFES training produced a significant increase in MEP magnitude throughout...

  1. Rehabilitation effect of the third generation functional electrical stimulation combined with task oriented training for upper limb function after stroke%第三代功能性电刺激联合任务导向训练对卒中后上肢功能的康复作用

    Institute of Scientific and Technical Information of China (English)

    朱琳; 梁军; 张冉; 刘霖; 宋为群

    2014-01-01

    目的:探讨第三代功能电刺激(FES)联合任务导向训练对卒中后上肢功能恢复的作用。方法选择病程3~12个月的初发卒中患者40例,按病例单双号分为FES组和对照组,每组20例。两组患者均接受传统的康复训练,1次/d,30 min/次,5 d/周,共12周。FES组另给予12周的FES治疗,1次/d,15 min/次,5 d/周;根据上肢功能状况给予患者被动电刺激、触发反馈电刺激、助力反馈电刺激结合任务导向训练(杯子训练)的作业治疗。疗效评定采用改良的Ashworth量表(MAS)、Brunnstrom分级量表、Fugl-Meyer运动功能量表(上肢部分,FMA)及腕关节背伸的主动关节活动度(WEAROM)测评。结果(1)治疗前FES组与对照组各项观察指标差异均无统计学意义。(2)治疗后两组MAS和Brunnstrom量表评分均较治疗前有所改善,差异有统计学意义(P<0.01);但FES组与对照组比较,MAS和Brunnstrom量表的治疗前-后评分差值[分别为(0.7±0.3)、(0.8±0.4)分和(0.6±0.2)、(0.7±0.4)分]差异均无统计学意义。(3)两组 FMA评分和WE-AROM均较治疗前提高,差异有统计学意义(P<0.05);FES组FMA评分的治疗前-后差值为(8.3±4.0)分,高于对照组的(4.3±2.5)分;FES组WEAROM的治疗前-后差值为(21±10)度,高于对照组的(14±6)度,差异均有统计学意义(P<0.05)。结论与传统的康复训练相比,结合了FES治疗的康复训练对于卒中患者上肢运动功能改善及腕关节背伸的关节活动度提高效果更明显。但对上肢痉挛改善效果不明显。%Objective To investigate the rehabilitation effect of the third generation functional electrical stimulation (FES)for upper limb function after stroke. Methods Forty patients with first attack of stroke (the course of disease was 3 to 12 months)were enrolled. They were divided into either a FES

  2. The electricity industry perspective

    Energy Technology Data Exchange (ETDEWEB)

    Orchison, K. [Electricity Supply Association of Australia Ltd., Sydney, NSW (Australia)

    1996-12-31

    A revolution has been sweeping through the electricity supply business in Australia in the past decade and especially in the past five years. Electricity suppliers were early adherents to the pursuit of economic reform, beginning a drive towards greater efficiency in the mid-1980s and accelerating the process as government, pushed in turn by industry and commerce, took up pursuit of competitive energy markets, including radical restructuring of the State-owned utility organizations. The aim of this paper is to provide an overview of the electricity supply business. It include an outline of the major challenges confronting the electricity supply business in Australia, particularly as a result of the introduction of competitive markets in electricity and natural gas. Deregulation will see the providers of electricity and gas reposition themselves as organizations able to supply the total energy needs of customers. A de-regulated electricity market also offers cogeneration plants new opportunities to sell surplus electricity to generators, distribution businesses or directly to customers. The major frontiers facing the electricity supply business in Australia is seen to be that of productively channelling change. How this is handled has substantial implications for those who purchase electricity, suppliers of fuel to electricity generators or rivals in the marketplace. (author).

  3. The Electric Vehicle Development

    DEFF Research Database (Denmark)

    Wang, Jingyu; Yingqi, Liu; Kokko, Ari

    2014-01-01

    In order to respond to the energy crisis and environment problem, countries carry out their research and promotion about electric vehicles. As the ten cities one thousand new energy buses started in 2009, the new energy vehicles have been greatly developed in China, while the development...... of electric vehicles is not that good. This paper selects four cities-Los Angeles, Kanagawa, Hamburg, Amsterdam-that promote electric vehicles successfully and deeply analyzes the development of electric vehicles in these four cities and analyzes the factors that affect the development of electric vehicles...... in three aspects-city environment, government and stakeholders. Then the paper discusses the promotion ways and role of government and consumer. Finally, the paper offers some suggestions to promote electric vehicles in China: focusing on feasibility and adaptability of electric vehicles, playing...

  4. Economics of electricity

    Science.gov (United States)

    Erdmann, G.

    2015-08-01

    The following text is an introduction into the economic theory of electricity supply and demand. The basic approach of economics has to reflect the physical peculiarities of electric power that is based on the directed movement of electrons from the minus pole to the plus pole of a voltage source. The regular grid supply of electricity is characterized by a largely constant frequency and voltage. Thus, from a physical point of view electricity is a homogeneous product. But from an economic point of view, electricity is not homogeneous. Wholesale electricity prices show significant fluctuations over time and between regions, because this product is not storable (in relevant quantities) and there may be bottlenecks in the transmission and distribution grids. The associated non-homogeneity is the starting point of the economic analysis of electricity markets.

  5. Electrical conductivity of collapsed multilayer graphene tubes

    OpenAIRE

    Mendoza, D.

    2011-01-01

    Synthesis of multilayer graphene on copper wires by a chemical vapor deposition method is reported. After copper etching, the multilayer tube collapses forming stripes of graphitic films, their electrical conductance as a function of temperature indicate a semiconductor-like behavior. Using the multilayer graphene stripes, a cross junction is built and owing to its electrical behavior we propose that a tunneling process exists in the device.

  6. 电针手足阳明经穴治疗慢传输型功能性便秘的临床疗效评价%Clinical effect assessment on therapy of electric acupuncture of yangming meridian for functional constipation with slow transmission

    Institute of Scientific and Technical Information of China (English)

    张昶; 刘赵丽; 周鹰; 徐耀; 熊会海; 马洪萍

    2013-01-01

    Objective:To evaluate the clinical effect of therapy of electric acupuncture on Yangming meridian for functional constipation with slow transmission.Methods:60 patients were randomly divided into electric acupuncture group of 30 patients,30 cases in control group.Tianshu,Zusanli,Hegu,Shangjuxu,were acupunctured in electric acupuncture group,once a day,5 times of one treatment.Control group takes prepulsid 10mg 3 times daily.Defecation time,constipation symptoms scales were observed before and after treatment.Results Effectiveness of electric acupuncture group was 93.1%,better than the control group.Electric acupuncture improved defecation time better (P < 0.05).Two groups both improved "defecation frequency"," force situation",and "shit character",and the electric acupuncture group had more advantages (P < 0.05).Conclusion:Electric acupuncture performed better than prepulsid in the treatment for functional constipation with slow transmission.%目的:评价电针治疗慢传输型功能性便秘的临床疗效,并探讨电针治疗慢传输型功能性便秘的价值.方法:60例患者随机分为电针组30例,对照组30例.电针组针刺天枢、合谷、足三里、上巨虚,每日1次,5次为1个疗程,治疗4个疗程.对照组口服普瑞博思,每日3次,4周后评价疗效,并观察治疗前后排便时间、便秘症状积分的变化.结果:电针组有效率93.1%,疗效优于对照组;电针改善排便时间更有优势(P<0.05),2组在改善“排便次数、用力情况、大便情况”方面均有效,电针在改善“排便次数、大便性状”方面更有优势(P<0.05).结论:电针组在缩短排便时间、提高排便次数、改善大便性状方面具有显著优势,且远期疗效也较好.

  7. Market Monitoring and Analysis: Electricity Sector

    Directory of Open Access Journals (Sweden)

    Helga Zogolli

    2015-10-01

    Full Text Available EU electricity liberalisation remains an essential energy reform programme, in scale in any other major region of the world. While other regions of the world have seen major pauses to their energy market reforms (most notably in the United States, the EU in the form of the European Commission, continues to press ahead. Electricity market power in Albania is in a difficult situation as a consequence of the lack of the adequate home-brew electricity resources and the great dependency from the hydro resources, inadequacy of the interconnections capacity with the neighbouring networks of electricity power, the considerable technical and economic barriers, and the difficult financials.In countries where no “official” power pool has been set up, different kinds of privates’ entities, e.g. generators, distributors, traders, large consumers, stock exchanges, system operator etc. or a combination of them, have promoted the creation of PX-s. The idea is that because electricity is a homogeneous product, standardized contracts can be traded on organized marketplaces. Since such an initiative was not forbidden by any law or by the European Directives many project have emerged in response to different motivations.This process in Europe, known as the liberalization process, has had a wide impact on the European electricity industry.Electricity market liberalisation is the opening of the market to competition; the extension of vertical unbundling of transmission and distribution from the generation and retailing; and the introduction of an independent regulator.The focus of this project is an analysis of the role of electricity PX-s in the recently liberalized electricity markets of Europe. In the context of creating “a” competitive electricity market at a European level, the key questions considered are the functioning of these PX-s with respect to electricity characteristics, market design and regulatory framework. Keywords: Energy,‘Placing on

  8. Three essays on "making" electric power markets

    Science.gov (United States)

    Kench, Brian Thomas

    2000-10-01

    Technological change over the past three decades has altered most of the basic conditions in the electric power industry. Because of technical progress, the dominant paradigm has shifted from the provision of electric power by regulated and vertically integrated local natural monopolies to competition and vertical separation. In the first essay I provide a historical context of the electric industry's power current deregulation debate. Then a dynamic model of induced institutional change is used to investigate how endogenous technological advancements have induced radical institutional change in the generation and transmission segments of the electric power industry. Because the Federal Energy Regulatory Commission (FERC) ordered regulated utilities to provide open access to their transmission networks and to separate their generation and transmission functions, transmission networks have been used more intensively and in much different ways then in the past. The second essay tests experimentally the predictions of neoclassical theory for a radial electric power market under two alternative deregulated transmission institutions: financial transmission rights and physical transmission rights. Experimental evidence presented there demonstrates that an electric power market with physical transmission rights governing its transmission network generates more "right" market signals relative to a transmission network governed by financial transmission rights. The move to a greater reliance on markets for electric power is an idea that has animated sweeping and dramatic changes in the traditional business of electric power. The third essay examines two of the most innovative and complex initiatives of making electric power markets in the United States: California and PJM. As those markets mature and others are made, they must revise their governance mechanisms to eliminate rules that create inefficiency and adopt rules that work efficiently elsewhere. I argue that

  9. Competition in decentralized electricity markets: Three papers on electricity auctions

    Science.gov (United States)

    Harbord, David William Cameron

    This thesis consists of three self-contained papers on the analysis of electricity auctions written over a period of twelve years. The first paper models price competition in a decentralized wholesale market for electricity as a first-price, sealed-bid, multi-unit auction. In both the pure and mixed-strategy equilibria of the model, above marginal cost pricing and inefficient despatch of generating units occur. An alternative regulatory pricing rule is considered and it is shown that offering to supply at marginal cost can be induced as a dominant strategy for all firms. The second paper analyses strategic interaction between long-term contracts and price competition in the British electricity wholesale market, and confirms that forward contracts will tend to put downward pressure on spot market prices. A 'strategic commitment' motive for selling forward contracts is also identified: a generator may commit itself to bidding lower prices into the spot market in order to ensure that it will be despatched with its full capacity. The third paper characterizes bidding behavior and market outcomes in uniform and discriminatory electricity auctions. Uniform auctions result in higher average prices than discriminatory auctions, but the ranking in terms of productive efficiency is ambiguous. The comparative effects of other market design features, such as the number of steps in suppliers' bid functions, the duration of bids and the elasticity of demand are analyzed. The paper also clarifies some methodological issues in the analysis of electricity auctions. In particular we show that analogies with continuous share auctions are misplaced so long as firms are restricted to a finite number of bids.

  10. Mechanics of advanced functional materials

    CERN Document Server

    Wang, Biao

    2013-01-01

    Mechanics of Advanced Functional Materials emphasizes the coupling effect between the electric and mechanical field in the piezoelectric, ferroelectric and other functional materials. It also discusses the size effect on the ferroelectric domain instability and phase transition behaviors using the continuum micro-structural evolution models. Functional materials usually have a very wide application in engineering due to their unique thermal, electric, magnetic, optoelectronic, etc., functions. Almost all the applications demand that the material should have reasonable stiffness, strength, fracture toughness and the other mechanical properties. Furthermore, usually the stress and strain fields on the functional materials and devices have some important coupling effect on the functionality of the materials. Much progress has been made concerning the coupling electric and mechanical behaviors such as the coupled electric and stress field distribution in piezoelectric solids, ferroelectric domain patterns in ferr...

  11. The electricity market 2002

    International Nuclear Information System (INIS)

    The purpose of the 'Electricity market 2002' publication is to meet the need for generalized and readily accessible information on the conditions on the Nordic market. Iceland is not included in the description. The publication also includes summaries of information from recent years concerning electricity generation and utilization in the Nordic countries, the structure of the electricity market from the players' perspective, trade in electricity in the Nordic countries and in Northern Europe, electricity prices in the Nordic and other countries, and the impact of the electricity sector on the environment. The publication contains data on electricity generation and use during the past years, structure of the electricity market, trade in electricity in the Nordic countries and northern Europe, electricity prices in the Nordic countries and other countries as well as impact of electricity generation system on the environment. The market price of electricity is affected by a number of factors, including fuel prices, availability of water, and the power and energy balances of the various countries. The availability of water in Norway and Sweden has been very good in recent years, which has had a major influence on the price. 1996 was a dry year, which led to a high system price on Nord Pool. The price of electricity then dropped and has remained at a relatively low level up to the year 2001. The price of electricity rose during the spring of 2001 and remained at a higher level also during the summer months. The main reason was that the availability of water was lower than normal in Norway during the early part of the year. This created a higher demand for imported electricity in Norway and caused some apprehension that the year would be dry. The total price of electricity to the end users has not followed the system price development. The total cost of electricity to the end consumers consists of three items, i.e. the price of electricity, the network charges and

  12. 采用独立分量分析观察经皮穴位电针刺激对脑功能的影响%Effects of Transcutaneous Electrical Acupoint Stimulation on Brain Function Explored with Independent Component Analysis

    Institute of Scientific and Technical Information of China (English)

    魏鹏绪; 卢虎英; 徐基民

    2007-01-01

    Objective To explore fMRI data with independent component analysis (ICA) in order to investigate effects of transcutaneous electrical acupoint stimulation (TEAS) on brain function. Methods The experiment was performed on a whole-body 1.5 T GE Signa Excite MRI scanner with which the brain oxygenation level dependent (BOLD)/EPI images were acquired from a female traumatic brain injury patient. A block designed protocol was used. Both durations of rest and TEAS were 30 seconds. The data processing was performed with GIFT, Statistical Parametric Mapping 5 (SPM5) and MRIcro. Results from ICA and SPM were compared. Results Extended Infomax algorithm provided by GIFT found thirteen independent components (ICs), each of which contained a spatial map and a corresponding time course. The spatial maps associated with task-related ICs resembled the activation maps from SPM5 but were not totally identical. In addition, the time courses of these ICs differed from the shape of canonical HRF model used by SPM. Conclusion ICA is a good choice to investigate data and obtain prior knowledge before using model-based methods such as SPM.%目的 使用独立分量分析方法探索督脉穴位经皮电刺激对脑功能的影响.方法 使用1.5T GE Signa Excite核磁成像仪对一位女性脑外伤患者进行BOLD成像.采用组块设计,静息期与刺激期交替,组块长度均为30 s.数据处理采用GIFT、SPM5和MRIcro软件进行,并将独立分量分析与SPM软件处理的结果进行比较.结果 采用GIFT中的扩展Infomax算法进行独立分量分析,显示有13个独立成分,每一独立成分包含一空间图和相应的时间变化曲线.任务相关性独立成分的空间激活图与SPM5的分析结果类似,但并不完全相同.此外,这些任务相关性独立成分的时间曲线与SPM所用的经典血流动力相应函数模型的形状并不一致.结论 在使用模型依赖的数据分析方法如SPM之前,可以使用独立分量分析探索fMRI数据并获得先验知识.

  13. 脑机接口控制的下肢功能性电刺激系统研究%Study on Brain-Computer Interface Controlled Functional Electrical Stimulation System for Lower Limbs

    Institute of Scientific and Technical Information of China (English)

    姚林; 张定国; 王颖

    2012-01-01

    In this work, in order to restore the movements of lower limbs for paralyzed patients, a functional electrical stimulation (FES) rehabilitation system based on brain-computer interface (BCI) was developed. BCI adopts the technology of steady-state visual evoked potential (SSVEP) based EEG. Linear discriminated analysis was used as the classifier to process frequency-domain features of EEG. Five types of motion intention can be recognized, I. E. Start, fast, slow, stop and idle states. The intention recognized was translated as a command to trigger FES system, and stimulated the concerned muscles of lower limbs to generate movements, meanwhile joint angles were measured. Six healthy subjects took part in the pure BCI experiments, and two of the subjects took part in experiments of swinging and walking movements controlled by BCI-FES separately. During swinging experiment, rectus femoris was stimulated. During walking experiment, iliopsoas, glutaeus maximus, rectus femoris, and hamstrings of two legs were stimulated. FES artifacts on EEG were analyzed during experiments. The results showed that the motion intention was well recognized ( average recognition accuracy rate was over 85% ), and the subjects can realize the expected lower limb movements via FES accordingly.%研发基于脑机接口控制的功能性电刺激系统,服务于下肢的运动康复.脑机接口采用的是基于稳态视觉诱发电位的脑电信号技术.使用线性判别分析分类器来处理脑电信号的频域特征,实现对下肢5种运动状态的控制意图识别,即开始、快速、慢速、停止和空闲状态.识别的意图转化为指令触发电刺激系统,刺激下肢的相关肌肉产生运动,并测量关节角度.设计的系统在6位正常受试者上进行了单纯的脑机接口实验,其中2位分别进行了脑机接口控制的小腿摆动与下肢行走的电刺激实验.在小腿摆动实验中刺激的是股直肌,行走运动实验中刺激的是两条腿

  14. 用于神经信号再生的神经功能电压驱动电路%Function electrical stimulation circuit for neural signal regeneration system

    Institute of Scientific and Technical Information of China (English)

    王珏; 李文渊; 王志功

    2007-01-01

    采用华润上华0.6 μm CMOS工艺,设计实现了一种用于神经信号再生微电子系统的低功耗、高增益功能电激励电压驱动电路.它可以用于驱动激励电极和与之相连的神经来再生神经信号.电路由2部分组成:全差分折叠式共源共栅放大器及带过载保护的互补型甲乙类输出级.电路采用了满摆幅的输入输出结构,保证了大输入电压范围和大输出电压范围.仿真结果表明,电路增益可以达到81dB,具有295 kHz的3 dB带宽.芯片面积为1.06 mm×0.52 mm.经流片实现后在片测试,在单电源+5 V下工作,直流功耗约为7.5 mW,输出电压幅度达到4.8 V;同时在单电源+3.3 V下也可正常工作.%A low-power, high-gain circuit for function electrical stimulation (FES) is designed for the microelectronic neural signal regeneration system based on CSMC (CSMC Technologies Corporation) 0. 6 μm CMOS (complementary metal-oxide-semiconductor transistor) technology. It can be used to stimulate microelectrodes connected with the nerve bundles to regenerate neural signals. This circuit consists of two stages: a full differential folded-cascode amplifier input stage and a complementary class-AB output stage with an overload protection circuit. The rail-to-rail input and output stages are used to ensure a wide range of input and output voltages. The simulation results show that the gain of the circuit is 81 dB;the 3 dB-bandwidth is 295 kHz. The chip occupies a die area of 1.06 mm × 0. 52 mm. The on-wafer measurement results show that under a single supply voltage of + 5 V, the DC power consumption is about 7.5 mW and the output voltage amplitude is 4. 8 V. The chip can also run well under single supply voltage of + 3.3 V.

  15. Electric power monthly

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    The Energy Information Administration (EIA) prepares the Electric Power Monthly (EPM) for a wide audience including Congress, Federal and State agencies, the electric utility industry, and the general public. This publication provides monthly statistics for net generation, fossil fuel consumption and stocks, quantity and quality of fossil fuels, cost of fossil fuels, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fossil fuels are also displayed for the North American Electric Reliability Council (NERC) regions. The EIA publishes statistics in the EPM on net generation by energy source, consumption, stocks, quantity, quality, and cost of fossil fuels; and capability of new generating units by company and plant. The purpose of this publication is to provide energy decisionmakers with accurate and timely information that may be used in forming various perspectives on electric issues that lie ahead.

  16. Thermoacoustic magnetohydrodynamic electrical generator

    Science.gov (United States)

    Wheatley, John C.; Swift, Gregory W.; Migliori, Albert

    1986-01-01

    A thermoacoustic magnetohydrodynamic electrical generator includes an intrinsically irreversible thermoacoustic heat engine coupled to a magnetohydrodynamic electrical generator. The heat engine includes an electrically conductive liquid metal as the working fluid and includes two heat exchange and thermoacoustic structure assemblies which drive the liquid in a push-pull arrangement to cause the liquid metal to oscillate at a resonant acoustic frequency on the order of 1,000 Hz. The engine is positioned in the field of a magnet and is oriented such that the liquid metal oscillates in a direction orthogonal to the field of the magnet, whereby an alternating electrical potential is generated in the liquid metal. Low-loss, low-inductance electrical conductors electrically connected to opposite sides of the liquid metal conduct an output signal to a transformer adapted to convert the low-voltage, high-current output signal to a more usable higher voltage, lower current signal.

  17. Electricity securitization in China

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Song, Chang [Renmin University of China, Beijing (China). School of Business; Wang, J.H. [Illinois Institute of Technology, Chicago (United States). Department of Electrical and Computer Engineering; Xie, Jun [Wuhan University of Technology (China). School of Management

    2007-10-15

    This paper discusses the past and the status quo of electricity securitization in China. First, the stranded cost securitization in American electricity industry and the ongoing securitization progress in emerging market countries are investigated, which enlightens the way of electricity securitization in China. Through analysis of electricity industry in China, the paper proposes constructive policy suggestions for regulators who intend to prompt securitization to develop electricity infrastructure, and detailed recommendations for companies who plan to raise money at reduced cost. It is concluded that even though it is at the very beginning stage in China, securitization not only provides financing for investment projects, but also speeds up the reform by stranded cost securitization, a novel idea for electricity industry in China. (author)

  18. Electrical system architecture

    Science.gov (United States)

    Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

    2008-07-15

    An electrical system for a vehicle includes a first power source generating a first voltage level, the first power source being in electrical communication with a first bus. A second power source generates a second voltage level greater than the first voltage level, the second power source being in electrical communication with a second bus. A starter generator may be configured to provide power to at least one of the first bus and the second bus, and at least one additional power source may be configured to provide power to at least one of the first bus and the second bus. The electrical system also includes at least one power consumer in electrical communication with the first bus and at least one power consumer in electrical communication with the second bus.

  19. Surface electrical properties experiment

    Science.gov (United States)

    Simmons, Gene; Strangway, David; Annan, Peter; Baker, Richard G.; Bannister, Lawrence; Brown, Raymon; Cooper, William; Cubley, Dean; deBettencourt, Joseph; England, Anthony W.; Groener, John; Kong, Jin-Au; LaTorraca, Gerald; Meyer, James; Nanda, Ved; Redman, David; Rossiter, James; Tsang, Leung; Urner, Joseph; Watts, Raymond

    1973-01-01

    The surface electrical properties (SEP) experiment was used to explore the subsurface material of the Apollo 17 landing site by means of electromagnetic radiation. The experiment was designed to detect electrical layering, discrete scattering bodies, and the possible presence of water. From the analysis of the data, it was expected that values of the electrical properties (dielectric constant and loss tangent) of lunar material in situ would be obtained.

  20. Electrical and electronic principles

    CERN Document Server

    Knight, S A

    1991-01-01

    Electrical and Electronic Principles, 2, Second Edition covers the syllabus requirements of BTEC Unit U86/329, including the principles of control systems and elements of data transmission. The book first tackles series and parallel circuits, electrical networks, and capacitors and capacitance. Discussions focus on flux density, electric force, permittivity, Kirchhoff's laws, superposition theorem, arrangement of resistors, internal resistance, and powers in a circuit. The text then takes a look at capacitors in circuit, magnetism and magnetization, electromagnetic induction, and alternating v