Vector electric field measurement via position-modulated Kelvin probe force microscopy

Science.gov (United States)

Dwyer, Ryan P.; Smieska, Louisa M.; Tirmzi, Ali Moeed; Marohn, John A.

2017-10-01

High-quality spatially resolved measurements of electric fields are critical to understanding charge injection, charge transport, and charge trapping in semiconducting materials. Here, we report a variation of frequency-modulated Kelvin probe force microscopy that enables spatially resolved measurements of the electric field. We measure electric field components along multiple directions simultaneously by employing position modulation and lock-in detection in addition to numeric differentiation of the surface potential. We demonstrate the technique by recording linescans of the in-plane electric field vector in the vicinity of a patch of trapped charge in a 2,7-diphenyl[1]benzothieno[3,2-b][1]benzothiophene (DPh-BTBT) organic field-effect transistor. This technique is simple to implement and should be especially useful for studying electric fields in spatially inhomogeneous samples like organic transistors and photovoltaic blends.

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

Science.gov (United States)

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

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

Electric field and dielectrophoretic force on a dielectric particle chain in a parallel-plate electrode system

International Nuclear Information System (INIS)

Techaumnat, B; Eua-arporn, B; Takuma, T

2004-01-01

This paper presents results of calculations of the electric field and dielectrophoretic force on a dielectric particle chain suspended in a host liquid lying between parallel-plate electrodes. The method of calculation is based on the method of multipole images using the multipole re-expansion technique. We have investigated the effect of the particle permittivity, the tilt angle (between the chain and the applied field) and the chain arrangement on the electric field and force. The results show that the electric field intensification rises in accordance with the increase in the ratio of the particle-to-liquid permittivity, Γ ε . The electric field at the contact point between the particles decreases with increasing tilt angle, while the maximal field at the contact point between the particles and the plate electrodes is almost unchanged. The maximal field can be approximated by a simple formula, which is a quadratic function of Γ ε . The dielectrophoretic force depends significantly on the distance from other particles or an electrode. However, for the tilt angles in this paper, the horizontal force on the upper particle of the chain always has the direction opposite to the shear direction. The maximal horizontal force of a chain varies proportional to (Γ ε - 1) 1.7 if the particles in the chain are still in contact with each other. The approximated force, based on the force on an isolated chain, has been compared with our calculation results. The comparison shows that no approximation model agrees well with our results throughout the range of permittivity ratios

Design and simulation of superconducting Lorentz Force Electrical Impedance Tomography (LFEIT)

Energy Technology Data Exchange (ETDEWEB)

Shen, Boyang, E-mail: bs506@cam.ac.uk; Fu, Lin, E-mail: lf359@cam.ac.uk; Geng, Jianzhao, E-mail: jg717@cam.ac.uk; Zhang, Xiuchang, E-mail: xz326@cam.ac.uk; Zhang, Heng, E-mail: hz301@cam.ac.uk; Dong, Qihuan, E-mail: qd210@cam.ac.uk; Li, Chao, E-mail: cl644@cam.ac.uk; Li, Jing, E-mail: jl908@cam.ac.uk; Coombs, T.A., E-mail: tac1000@cam.ac.uk

2016-05-15

Highlights: • Design of superconducting magnets using Halbach Array configuration. • Combination of superconducting magnets together with Lorentz Force Electrical Impedance Tomography (LFEIT) system. • Simulation of superconducting LFEIT system based on the theory of magneto-acoustic effect. - Abstract: Lorentz Force Electrical Impedance Tomography (LFEIT) is a hybrid diagnostic scanner with strong capability for biological imaging, particularly in cancer and haemorrhages detection. This paper presents the design and simulation of a novel combination: a superconducting magnet together with LFEIT system. Superconducting magnets can generate magnetic field with high intensity and homogeneity, which could significantly enhance the imaging performance. The modelling of superconducting magnets was carried out using Finite Element Method (FEM) package, COMSOL Multiphysics, which was based on Partial Differential Equation (PDE) model with H-formulation coupling B-dependent critical current density and bulk approximation. The mathematical model for LFEIT system was built based on the theory of magneto-acoustic effect. The magnetic field properties from magnet design were imported into the LFEIT model. The basic imaging of electrical signal was developed using MATLAB codes. The LFEIT model simulated two samples located in three different magnetic fields with varying magnetic strength and homogeneity.

Effect of calcium chloride concentration on output force in electrical actuator made of sodium alginate gel

Science.gov (United States)

Wu, Yuda; Zhao, Gang; Wei, Chengye; Liu, Shuang; Fu, Yu; Liu, Xvxiong

2018-01-01

As a kind of artificial muscle intelligent material, the biological gel electric driver has the advantages of low driving voltage, large strain, good biological compatibility, good flexibility, low price, etc. The application prospect is broad and it has high academic value. Alginate, as a common substance in sea, has characteristics of low cost, green and pollution-free. Therefore,this paper obtains biological gel electric actuator by sodium alginate and calcium chloride. Effects on output force of the electric actuator is researched by changing the crosslinking of calcium chloride concentration and the output force enhancement mechanism is analyzed in this paper.

Transfer functions of laminar premixed flames subjected to forcing by acoustic waves, AC electric fields, and non-thermal plasma discharges

KAUST Repository

Lacoste, Deanna

2016-06-23

The responses of laminar methane-air flames to forcing by acoustic waves, AC electric fields, and nanosecond repetitively pulsed (NRP) glow discharges are reported here. The experimental setup consists of an axisymmetric burner with a nozzle made from a quartz tube. Three different flame geometries have been studied: conical, M-shaped and V-shaped flames. A central stainless steel rod is used as a cathode for the electric field and plasma excitations. The acoustic forcing is obtained with a loudspeaker located at the bottom part of the burner. For forcing by AC electric fields, a metallic grid is placed above the rod and connected to an AC power supply. Plasma forcing is obtained by applying high-voltage pulses of 10-ns duration applied at 10 kHz, between the rod and an annular stainless steel ring, placed at the outlet of the quartz tube. The chemiluminescence of CH is used to determine the heat release rate fluctuations. For forcing by acoustic waves and plasma, the geometry of the flame plays a key role in the response of the combustion, while the flame shape does not affect the response of the combustion to electric field forcing. The flame response to acoustic forcing of about 10% of the incoming flow is similar to those obtained in the literature. The flames are found to be responsive to an AC electric field across the whole range of frequencies studied. A forcing mechanism, based on the generation of ionic wind, is proposed. The gain of the transfer function obtained for plasma forcing is found to be up to 5 times higher than for acoustic forcing. A possible mechanism of plasma forcing is introduced.

Transfer functions of laminar premixed flames subjected to forcing by acoustic waves, AC electric fields, and non-thermal plasma discharges

KAUST Repository

Lacoste, Deanna; Xiong, Yuan; Moeck, Jonas P.; Chung, Suk-Ho; Roberts, William L.; Cha, Min

2016-01-01

The responses of laminar methane-air flames to forcing by acoustic waves, AC electric fields, and nanosecond repetitively pulsed (NRP) glow discharges are reported here. The experimental setup consists of an axisymmetric burner with a nozzle made from a quartz tube. Three different flame geometries have been studied: conical, M-shaped and V-shaped flames. A central stainless steel rod is used as a cathode for the electric field and plasma excitations. The acoustic forcing is obtained with a loudspeaker located at the bottom part of the burner. For forcing by AC electric fields, a metallic grid is placed above the rod and connected to an AC power supply. Plasma forcing is obtained by applying high-voltage pulses of 10-ns duration applied at 10 kHz, between the rod and an annular stainless steel ring, placed at the outlet of the quartz tube. The chemiluminescence of CH is used to determine the heat release rate fluctuations. For forcing by acoustic waves and plasma, the geometry of the flame plays a key role in the response of the combustion, while the flame shape does not affect the response of the combustion to electric field forcing. The flame response to acoustic forcing of about 10% of the incoming flow is similar to those obtained in the literature. The flames are found to be responsive to an AC electric field across the whole range of frequencies studied. A forcing mechanism, based on the generation of ionic wind, is proposed. The gain of the transfer function obtained for plasma forcing is found to be up to 5 times higher than for acoustic forcing. A possible mechanism of plasma forcing is introduced.

Linearity of electrical impedance tomography during maximum effort breathing and forced expiration maneuvers.

Science.gov (United States)

Ngo, Chuong; Leonhardt, Steffen; Zhang, Tony; Lüken, Markus; Misgeld, Berno; Vollmer, Thomas; Tenbrock, Klaus; Lehmann, Sylvia

2017-01-01

Electrical impedance tomography (EIT) provides global and regional information about ventilation by means of relative changes in electrical impedance measured with electrodes placed around the thorax. In combination with lung function tests, e.g. spirometry and body plethysmography, regional information about lung ventilation can be achieved. Impedance changes strictly correlate with lung volume during tidal breathing and mechanical ventilation. Initial studies presumed a correlation also during forced expiration maneuvers. To quantify the validity of this correlation in extreme lung volume changes during forced breathing, a measurement system was set up and applied on seven lung-healthy volunteers. Simultaneous measurements of changes in lung volume using EIT imaging and pneumotachography were obtained with different breathing patterns. Data was divided into a synchronizing phase (spontaneous breathing) and a test phase (maximum effort breathing and forced maneuvers). The EIT impedance changes correlate strictly with spirometric data during slow breathing with increasing and maximum effort ([Formula: see text]) and during forced expiration maneuvers ([Formula: see text]). Strong correlations in spirometric volume parameters [Formula: see text] ([Formula: see text]), [Formula: see text]/FVC ([Formula: see text]), and flow parameters PEF, [Formula: see text], [Formula: see text], [Formula: see text] ([Formula: see text]) were observed. According to the linearity during forced expiration maneuvers, EIT can be used during pulmonary function testing in combination with spirometry for visualisation of regional lung ventilation.

Force and Motion Characteristics of Contamination Particles near the High Voltage End of UHVDC Insulator

Directory of Open Access Journals (Sweden)

Lei Lan

2017-07-01

Full Text Available It is important to reveal the relations of physical factors to deposition of contaminants on insulator. In this paper, the simulation model of high voltage end of insulator was established to study the force and motion characteristics of particles affected by electric force and airflow drag force near the ultra-high voltage direct current (UHVDC insulator. By finite element method, the electric field was set specially to be similar to the one near practical insulator, the steady fluid field was simulated. The electric force and air drag force were loaded on the uniformly charged particles. The characteristics of the two forces on particles, the relationship between quantity of electric charge on particles and probability of particles contacting the insulator were analyzed. It was found that, near the sheds, airflow drag force on particles is significantly greater than electric force with less electric charge. As the charge multiplies, electric force increases linearly, airflow drag force grows more slowly. There is a trend that the magnitude of electric force and drag force is going to similar. Meanwhile, the probability of particles contacting the insulator is increased too. However, at a certain level of charge which has different value with different airflow velocity, the contact probability has extremum here. After exceeding the value, as the charge increasing, the contact probability decreases gradually.

DOE Task Force meeting on Electrical Breakdown of Insulating Ceramics in a High Radiation Field

International Nuclear Information System (INIS)

Green, P.H.

1991-08-01

This volume contains the abstracts and presentation material from the Research Assistance Task Force Meeting ''Electrical Breakdown of Insulating Ceramics in a High-Radiation Field.'' The meeting was jointly sponsored by the Office of Basic Energy Sciences and the Office of Fusion Energy of the US Department of Energy in Vail, Colorado, May 28--June 1, 1991. The 26 participants represented expertise in fusion, radiation damage, electrical breakdown, ceramics, and semiconductor and electronic structures. These participants came from universities, industries, national laboratories, and government. The attendees represented eight nations. The Task Force meeting was organized in response to the recent discovery that a combination of temperature, electric field, and radiation for an extended period of time has an unexplained adverse effect in ceramics, termed radiation-enhanced electrical degradation (REED). REED occurs after an incubation period and continues to accelerate with irradiation until the ceramics can no longer be regarded as insulators. It appears that REED is irreversible and the ceramic insulators cannot be readily annealed or otherwise repaired for future services. This effect poses a serious threat for fusion reactors, which require electrical insulators in diagnostic devices, in radio frequency and neutral beam systems, and in magnetic assemblies. The problem of selecting suitable electrical insulating materials in thus far more serious than previously anticipated

Analyzing driving forces behind changes in energy vulnerability of Spanish electricity generation through a Divisia index-based method

International Nuclear Information System (INIS)

Fernández González, P.; Moreno, B.

2015-01-01

Highlights: • We propose and develop the LMDI approach to factorize changes in electricity bill vulnerability. • Spanish vulnerability (1995–2011) markedly grew mainly by increasing gas dependence. • Fuel price increase and growing importance of electricity damage energy security. • Energy intensity advances & fuel diversification: insufficient to drive vulnerability. • Main recommendation: enhance internal energy market and common external EU strategy. - Abstract: High energy dependence on fossil raises vulnerability concerns about security of supply and energy cost. This research examines the impact of high dependence of imported fuels for power generation in Spain through the quantification and analysis of the driving forces behind the change in its electricity bill. Following logarithmic mean Divisia indexes approach, we present and perform a new method that enables a complete decomposition of changes in electricity vulnerability into contributions from several drivers. In fact, we identify five predefined factors behind the variations in vulnerability in Spain during the 1998–2011 period: fuel price, average heat rate, fuel dependence, degree of electricity importance and energy intensity. The application of this approach reveals a significant increase in Spanish vulnerability in the last two decades, promoted by increments in fuel price and importance of electricity over the primary energy consumption, but especially by increasing fuel dependence (particularly gas dependence). Therefore, findings mainly advocate for those strategies aimed at reducing Spanish energy dependence. Also those improving thermal efficiency and energy intensity are indicated

Estimation of longitudinal force, lateral vehicle speed and yaw rate for four-wheel independent driven electric vehicles

Science.gov (United States)

Chen, Te; Xu, Xing; Chen, Long; Jiang, Haobing; Cai, Yingfeng; Li, Yong

2018-02-01

Accurate estimation of longitudinal force, lateral vehicle speed and yaw rate is of great significance to torque allocation and stability control for four-wheel independent driven electric vehicle (4WID-EVs). A fusion method is proposed to estimate the longitudinal force, lateral vehicle speed and yaw rate for 4WID-EVs. The electric driving wheel model (EDWM) is introduced into the longitudinal force estimation, the longitudinal force observer (LFO) is designed firstly based on the adaptive high-order sliding mode observer (HSMO), and the convergence of LFO is analyzed and proved. Based on the estimated longitudinal force, an estimation strategy is then presented in which the strong tracking filter (STF) is used to estimate lateral vehicle speed and yaw rate simultaneously. Finally, co-simulation via Carsim and Matlab/Simulink is carried out to demonstrate the effectiveness of the proposed method. The performance of LFO in practice is verified by the experiment on chassis dynamometer bench.

Force modulation for improved conductive-mode atomic force microscopy

NARCIS (Netherlands)

Koelmans, W.W.; Sebastian, Abu; Despont, Michel; Pozidis, Haris

We present an improved conductive-mode atomic force microscopy (C-AFM) method by modulating the applied loading force on the tip. Unreliable electrical contact and tip wear are the primary challenges for electrical characterization at the nanometer scale. The experiments show that force modulation

Rising electricity consumption: Driving forces and consequences. The case of rural Zanzibar

Energy Technology Data Exchange (ETDEWEB)

Winther, Tanja [Centre for Development and the Environment (SUM), Univ. of Oslo (Norway)

2007-07-01

The paper addresses the current, rising electricity consumption in the southern, rural locality of Zanzibar and seeks to account for the range of driving forces behind people's changed practices. The author argues that these forces are, on the one hand, determined by the availability of new technologies and through global and national institutions and influences such as Islam, commercials and changes in the governmental sector (health, education). On the other hand, the paper explores the way such influences interplay with the internal dynamics related to increasing consumption. Through an analysis of the particular character and dynamics of social and cultural life in this region, the author explains why some practices are less likely to change than other practices. For example, people in Zanzibar keep electricity (freezers and stoves) at a distance from their food. By contrast, electric light is perceived as intimately related to education, as illustrated when school children are sent to school for night classes before important exams. To which extent may general approaches to the study of energy consumption draw on this empirical case from Zanzibar? In other contexts, the patterns of people's electricity use certainly differ. In terms of sustainable energy policies, each locality has a particular set of challenges and goals, which to varying degree may be related to poverty reduction and concern for the environment. Methodologically, however, the author argues that the phenomenon of energy consumption may be studied and understood within the same framework of analysis; one that pays attention to both external and internal dynamics, the material and social aspects of technologies and the importance of power relations, gender and negotiations.

Intraoral conversion of occlusal force to electricity and magnetism by biting of piezoelectric elements.

Science.gov (United States)

Kameda, Takashi; Ohkuma, Kazuo; Sano, Natsuki; Ogura, Hideo; Terada, Kazuto

2012-01-01

Very weak electrical, magnetic and ultrasound signal stimulations are known to promote the formation, metabolism, restoration and stability of bone and surrounding tissues after treatment and operations. We have therefore investigated the possibility of intraoral generation of electricity and magnetism by occlusal force in an in vitro study. Biting bimorph piezoelectric elements with lead zirconate titanate (PZT) using dental models generated appropriate magnetism for bone formation, i. e. 0.5-0.6 gauss, and lower electric currents and higher voltages, i. e. 2.0-6.0 μA at 10-22 V (appropriate levels are 30 μA and 1.25 V), as observed by a universal testing machine. The electric currents and voltages could be changed using amplifier circuits. These results show that intraoral generation of electricity and magnetism is possible and could provide post-operative stabilization and activation of treated areas of bone and the surrounding tissues directly and/or indirectly by electrical, magnetic and ultrasound stimulation, which could accelerate healing.

Electric current-driven migration of electrically neutral particles in liquids

International Nuclear Information System (INIS)

Zhang, Xinfang; Qin, Rongshan

2014-01-01

We design and experimentally demonstrate a migration of electrically neutral particles in liquids driven by electric current according to the discrepancies of their electrical conductivities. A force from electric current to electrically neutral particles has been identified to drive the particles toward the lateral surface from the centre of suspension via three distinguishable zones, namely, pushing, trapping, and expelling zones. The driving force can overtake gravity in practical cases. The property of the force is found neither similar to that of the force in electromagnetophoresis nor similar to that of the electromigration force in terms of direction and magnitude. An expression for the force at the pushing zone has been developed based on the numerical calculation of the thermodynamics of suspension fluids. The excellent agreement between numerical calculations and experimental data demonstrates that our calculation provides fundamental and predictive insight into particles separation from the liquids. Therefore, it is possible to use the force in many engineering applications such as separation of particles according to the differences of their electrical conductivities

Estimation of Longitudinal Force and Sideslip Angle for Intelligent Four-Wheel Independent Drive Electric Vehicles by Observer Iteration and Information Fusion.

Science.gov (United States)

Chen, Te; Chen, Long; Xu, Xing; Cai, Yingfeng; Jiang, Haobin; Sun, Xiaoqiang

2018-04-20

Exact estimation of longitudinal force and sideslip angle is important for lateral stability and path-following control of four-wheel independent driven electric vehicle. This paper presents an effective method for longitudinal force and sideslip angle estimation by observer iteration and information fusion for four-wheel independent drive electric vehicles. The electric driving wheel model is introduced into the vehicle modeling process and used for longitudinal force estimation, the longitudinal force reconstruction equation is obtained via model decoupling, the a Luenberger observer and high-order sliding mode observer are united for longitudinal force observer design, and the Kalman filter is applied to restrain the influence of noise. Via the estimated longitudinal force, an estimation strategy is then proposed based on observer iteration and information fusion, in which the Luenberger observer is applied to achieve the transcendental estimation utilizing less sensor measurements, the extended Kalman filter is used for a posteriori estimation with higher accuracy, and a fuzzy weight controller is used to enhance the adaptive ability of observer system. Simulations and experiments are carried out, and the effectiveness of proposed estimation method is verified.

Modeling electrically active viscoelastic membranes.

Directory of Open Access Journals (Sweden)

Sitikantha Roy

Full Text Available The membrane protein prestin is native to the cochlear outer hair cell that is crucial to the ear's amplification and frequency selectivity throughout the whole acoustic frequency range. The outer hair cell exhibits interrelated dimensional changes, force generation, and electric charge transfer. Cells transfected with prestin acquire unique active properties similar to those in the native cell that have also been useful in understanding the process. Here we propose a model describing the major electromechanical features of such active membranes. The model derived from thermodynamic principles is in the form of integral relationships between the history of voltage and membrane resultants as independent variables and the charge density and strains as dependent variables. The proposed model is applied to the analysis of an active force produced by the outer hair cell in response to a harmonic electric field. Our analysis reveals the mechanism of the outer hair cell active (isometric force having an almost constant amplitude and phase up to 80 kHz. We found that the frequency-invariance of the force is a result of interplay between the electrical filtering associated with prestin and power law viscoelasticity of the surrounding membrane. Paradoxically, the membrane viscoelasticity boosts the force balancing the electrical filtering effect. We also consider various modes of electromechanical coupling in membrane with prestin associated with mechanical perturbations in the cell. We consider pressure or strains applied step-wise or at a constant rate and compute the time course of the resulting electric charge. The results obtained here are important for the analysis of electromechanical properties of membranes, cells, and biological materials as well as for a better understanding of the mechanism of hearing and the role of the protein prestin in this mechanism.

Measuring q/m for Water Drops--An Introduction to the Effects of Electrical Forces

Science.gov (United States)

Hart, Francis X.

1974-01-01

Discusses an experiment which introduces students to the effects of electrical forces on the motion of macroscopic objects. Included are the proecedures of measuring the charge-to-mass ratio from deflections of charged water drops in horizontal fields and the overall charges delivered in a Faraday cup. (CC)

Assessing regional lung mechanics by combining electrical impedance tomography and forced oscillation technique.

Science.gov (United States)

Ngo, Chuong; Spagnesi, Sarah; Munoz, Carlos; Lehmann, Sylvia; Vollmer, Thomas; Misgeld, Berno; Leonhardt, Steffen

2017-08-29

There is a lack of noninvasive pulmonary function tests which can assess regional information of the lungs. Electrical impedance tomography (EIT) is a radiation-free, non-invasive real-time imaging that provides regional information of ventilation volume regarding the measurement of electrical impedance distribution. Forced oscillation technique (FOT) is a pulmonary function test which is based on the measurement of respiratory mechanical impedance over a frequency range. In this article, we introduce a new measurement approach by combining FOT and EIT, named the oscillatory electrical impedance tomography (oEIT). Our oEIT measurement system consists of a valve-based FOT device, an EIT device, pressure and flow sensors, and a computer fusing the data streams. Measurements were performed on five healthy volunteers at the frequencies 3, 4, 5, 6, 7, 8, 10, 15, and 20 Hz. The measurements suggest that the combination of FOT and EIT is a promising approach. High frequency responses are visible in the derivative of the global impedance index ΔZeit(t,fos). $\\Delta {Z_{{\\text{eit}}}}(t,{f_{{\\text{os}}}}).$ The oEIT signals consist of three main components: forced oscillation, spontaneous breathing, and heart activity. The amplitude of the oscillation component decreases with increasing frequency. The band-pass filtered oEIT signal might be a new tool in regional lung function diagnostics, since local responses to high frequency perturbation could be distinguished between different lung regions.

Griffiss Air Force Base integrated resource assessment. Volume 3, Electric resource assessment

Energy Technology Data Exchange (ETDEWEB)

Armstrong, P.R.; Shankle, S.A.; Elliott, D.B.; Stucky, D.J.; Keller, J.M.; Wahlstrom, R.R.; Dagle, J.E.; Gu, A.Y.

1993-09-01

The US Air Force Air Combat Command (ACC) has tasked the US Department of Energy (DOE) Federal Energy Management Program (FEMP) to identify, evaluate, and assist in acquiring all cost-effective energy projects at Griffiss Air Force Base (AFB). FEMP, with support from the Pacific Northwest Laboratory (PNL), is designing this model program for federal customers served by the Niagara Mohawk Power Company. The program with Griffiss AFB will (1) identify and evaluate all cost-effective electric energy projects; (2) develop a schedule for project acquisition considering project type, size, timing, capital requirements, as well as energy and dollar savings; and (3) secure 100% of the financing required to implement electric energy efficiency projects from Niagara Mohawk and have them procure the necessary contractors to perform detailed audits and install the technologies. This report provides the results of the electric energy resource opportunity (ERO) assessments performed by PNL at one of Niagara Mohawk`s primary federal facilities, the ACC Griffiss AFB facility located near Rome, New York. The results of the analyses of EROs are presented in seven common energy end-use categories. A narrative description of each ERO provides information on the initial cost, energy and dollar savings; impacts on operations and maintenance (O&M); and, when applicable, a discussion of energy supply and demand, energy security, and environmental issues. The evaluation methodology and technical and cost assumptions are also described for each ERO. Summary tables present the operational performance of energy end-use equipment before and after the implementation of each ERO and the results of the life-cycle cost analysis indicating the net present value (NPV) and savings-to-investment ratio (SIR) of each ERO.

The law of electromagnetic force

Directory of Open Access Journals (Sweden)

V.J. Kutkovetskyy

2014-06-01

Full Text Available Calculation peculiarities for Lorentz force, Ampere force, interaction of parallel electric currents, and the moment of electrical machines are analyzed. They have exceptions on application, and they are the rules which result from the law of electromagnetic force as coordinate derivative of the operating magnetic flow. An addition to the direction of electromagnetic force action is proposed. Standards of salient-pole electrical machine designing are considered.

Control of thumb force using surface functional electrical stimulation and muscle load sharing

Science.gov (United States)

2013-01-01

Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of individual muscle forces, described by a sigmoidal muscle recruitment curve and a single force direction. Methods Five able bodied subjects and five stroke subjects were strapped in a custom built setup. The forces perpendicular to the thumb in response to FES applied to three thumb muscles were measured. We evaluated the feasibility of using recruitment curve based force vector maps in predicting output forces. In addition, we developed a closed loop force controller. Load sharing between the three muscles was used to solve the redundancy problem having three actuators to control forces in two dimensions. The thumb force was controlled towards target forces of 0.5 N and 1.0 N in multiple directions within the individual’s thumb work space. Hereby, the possibilities to use these force vector maps and the load sharing approach in feed forward and feedback force control were explored. Results The force vector prediction of the obtained model had small RMS errors with respect to the actual measured force vectors (0.22±0.17 N for the healthy subjects; 0.17±0.13 N for the stroke subjects). The stroke subjects showed a limited work range due to limited force production of the individual muscles. Performance of feed forward control without feedback, was better in healthy subjects than in stroke subjects. However, when feedback control was added performances were similar between the two groups. Feedback force control lead, especially for the stroke subjects, to a reduction in stationary errors, which improved performance. Conclusions Thumb muscle responses to FES can be described by a single force direction and a sigmoidal recruitment curve. Force in desired direction can be

Electricity

CERN Document Server

Basford, Leslie

2013-01-01

Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

Atom-Pair Kinetics with Strong Electric-Dipole Interactions.

Science.gov (United States)

Thaicharoen, N; Gonçalves, L F; Raithel, G

2016-05-27

Rydberg-atom ensembles are switched from a weakly to a strongly interacting regime via adiabatic transformation of the atoms from an approximately nonpolar into a highly dipolar quantum state. The resultant electric dipole-dipole forces are probed using a device akin to a field ion microscope. Ion imaging and pair-correlation analysis reveal the kinetics of the interacting atoms. Dumbbell-shaped pair-correlation images demonstrate the anisotropy of the binary dipolar force. The dipolar C_{3} coefficient, derived from the time dependence of the images, agrees with the value calculated from the permanent electric-dipole moment of the atoms. The results indicate many-body dynamics akin to disorder-induced heating in strongly coupled particle systems.

Electrical Stimulation Frequency and Skeletal Muscle Characteristics: Effects on Force and Fatigue

Directory of Open Access Journals (Sweden)

Maria Vromans

2017-12-01

Full Text Available This investigation aimed to determine the force and muscle surface electromyography (EMG responses to different frequencies of electrical stimulation (ES in two groups of muscles with different size and fiber composition (fast- and slow-twitch fiber proportions during a fatigue-inducing protocol. Progression towards fatigue was evaluated in the abductor pollicis brevis (APB and vastus lateralis (VL when activated by ES at three frequencies (10, 35, and 50Hz. Ten healthy adults (mean age: 23.2 ± 3.0 years were recruited; participants signed an IRB approved consent form prior to participation. Protocols were developed to 1 identify initial ES current intensity required to generate the 25% maximal voluntary contraction (MVC at each ES frequency and 2 evaluate changes in force and EMG activity during ES-induced contraction at each frequency while progressing towards fatigue. For both muscles, stimulation at 10Hz required higher current intensity of ES to generate the initial force. There was a significant decline in force in response to ES-induced fatigue for all frequencies and for both muscles (p<0.05. However, the EMG response was not consistent between muscles. During the progression towards fatigue, the APB displayed an initial drop in force followed by an increase in EMG activity and the VL displayed a decrease in EMG activity for all frequencies. Overall, it appeared that there were some significant interactions between muscle size and fiber composition during progression towards fatigue for different ES frequencies. It could be postulated that muscle characteristics (size and fiber composition should be considered when evaluating progression towards fatigue as EMG and force responses are not consistent between muscles.

Revealing Abrupt and Spontaneous Ruptures of Protein Native Structure under picoNewton Compressive Force Manipulation.

Science.gov (United States)

Chowdhury, S Roy; Cao, Jin; He, Yufan; Lu, H Peter

2018-03-27

Manipulating protein conformations for exploring protein structure-function relationship has shown great promise. Although protein conformational changes under pulling force manipulation have been extensively studied, protein conformation changes under a compressive force have not been explored quantitatively. The latter is even more biologically significant and relevant in revealing protein functions in living cells associated with protein crowdedness, distribution fluctuations, and cell osmotic stress. Here we report our experimental observations on abrupt ruptures of protein native structures under compressive force, demonstrated and studied by single-molecule AFM-FRET spectroscopic nanoscopy. Our results show that the protein ruptures are abrupt and spontaneous events occurred when the compressive force reaches a threshold of 12-75 pN, a force amplitude accessible from thermal fluctuations in a living cell. The abrupt ruptures are sensitive to local environment, likely a general and important pathway of protein unfolding in living cells.

Electrical tomography using atomic force microscopy and its application towards carbon nanotube-based interconnects

International Nuclear Information System (INIS)

Schulze, A; Hantschel, T; Dathe, A; Eyben, P; Vandervorst, W; Ke, X

2012-01-01

The fabrication and integration of low-resistance carbon nanotubes (CNTs) for interconnects in future integrated circuits requires characterization techniques providing structural and electrical information at the nanometer scale. In this paper we present a slice-and-view approach based on electrical atomic force microscopy. Material removal achieved by successive scanning using doped ultra-sharp full-diamond probes, manufactured in-house, enables us to acquire two-dimensional (2D) resistance maps originating from different depths (equivalently different CNT lengths) on CNT-based interconnects. Stacking and interpolating these 2D resistance maps results in a three-dimensional (3D) representation (tomogram). This allows insight from a structural (e.g. size, density, distribution, straightness) and electrical point of view simultaneously. By extracting the resistance evolution over the length of an individual CNT we derive quantitative information about the resistivity and the contact resistance between the CNT and bottom electrode. (paper)

Effect of electrical stimulation and cooking temperature on the within-sample variation of cooking loss and shear force of lamb.

Science.gov (United States)

Lewis, P K; Babiker, S A

1983-01-01

Electrical stimulation decreased the shear force and increased the cooking loss in seven paired lamb Longissimus dorsi (LD) muscles. This treatment did not have any effect on the within-sample variation. Cooking in 55°, 65° and 75°C water baths for 90 min caused a linear increase in the cooking loss and shear force. There was no stimulation-cooking temperature interaction observed. Cooking temperature also had no effect on the within-sample variation. A possible explanation as to why electrical stimulation did not affect the within-sample variation is given. Copyright © 1983. Published by Elsevier Ltd.

Interference between electric and magnetic concepts in introductory physics

Directory of Open Access Journals (Sweden)

Thomas M. Scaife

2011-03-01

Full Text Available We investigate student confusion of concepts of electric and magnetic force. At various times during a traditional university-level course, we administered a series of simple questions about the direction of force on a charged particle moving through either an electric or a magnetic field. We find that after electric force instruction but before magnetic force instruction most students answer electric force questions correctly, and we replicate well-known results that many students incorrectly answer that magnetic forces are in the same direction as the magnetic field. After magnetic force instruction, most students answer magnetic force questions correctly, but surprisingly many students incorrectly answer that electric forces are perpendicular to electric fields, as would happen if a student confused electric forces with magnetic forces. As a further indication of interference between electric and magnetic concepts, we also find that students’ responses depend on whether electric or magnetic force questions are posed first, and this effect depends on whether electric or magnetic force was most recently taught.

Potential of mean force for electrical conductivity of dense plasmas

Science.gov (United States)

Starrett, C. E.

2017-12-01

The electrical conductivity in dense plasmas can be calculated with the relaxation-time approximation provided that the interaction potential between the scattering electron and the ion is known. To date there has been considerable uncertainty as to the best way to define this interaction potential so that it correctly includes the effects of ionic structure, screening by electrons and partial ionization. Current approximations lead to significantly different results with varying levels of agreement when compared to bench-mark calculations and experiments. We present a new way to define this potential, drawing on ideas from classical fluid theory to define a potential of mean force. This new potential results in significantly improved agreement with experiments and bench-mark calculations, and includes all the aforementioned physics self-consistently.

Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study

International Nuclear Information System (INIS)

Lesoil, Charles; Nonaka, Takahiro; Sekiguchi, Hiroshi; Osada, Toshiya; Miyata, Makoto; Afrin, Rehana; Ikai, Atsushi

2010-01-01

Recent studies of the gliding bacteria Mycoplasma mobile have identified a family of proteins called the Gli family which was considered to be involved in this novel and yet fairly unknown motility system. The 349 kDa protein called Gli349 was successfully isolated and purified from the bacteria, and electron microscopy imaging and antibody experiments led to the hypothesis that it acts as the 'leg' of M. mobile, responsible for attachment to the substrate as well as for gliding motility. However, more precise evidence of the molecular shape and function of this protein was required to asses this theory any further. In this study, an atomic force microscope (AFM) was used both as an imaging and a force measurement device to provide new information about Gli349 and its role in gliding motility. AFM images of the protein were obtained revealing a complex structure with both rigid and flexible parts, consistent with previous electron micrographs of the protein. Single-molecular force spectroscopy experiments were also performed, revealing that Gli349 is able to specifically bind to sialyllactose molecules and withstand unbinding forces around 70 pN. These findings strongly support the idea that Gli349 is the 'leg' protein of M. mobile, responsible for binding and also most probably force generation during gliding motility.

On the glitches in the force transmitted by an electrodynamic exciter to a structure

Science.gov (United States)

Rao, Dantam K.

1987-01-01

Around resonance, the force transmitted by an exciter into a structure will be smaller or greater than a reference force generated by its coils due to electromechanical interaction. A simple analysis is presented which reveals how this phenomenon of force drop-off is controlled by three factors. The first factor, called Armature Mass Factor, describes a purely mechanical interaction between the structure and the exciter. The electromechanical energy conversion and its interaction with the structure yields two additional factors, called Electrical Resistance and Electrical Inductance Factors. They describe the effects of coil resistance, inductance and magnetic field strength relative to structural damping and stiffness. Present analysis indicates that, under proper circumstances, more than 90 percent of the force drop-off can be eliminated if armature-to-structure mass ratio is smaller or equal to half of modal loss factor.

Force fields of charged particles in micro-nanofluidic preconcentration systems

Science.gov (United States)

Gong, Lingyan; Ouyang, Wei; Li, Zirui; Han, Jongyoon

2017-12-01

Electrokinetic concentration devices based on the ion concentration polarization (ICP) phenomenon have drawn much attention due to their simple setup, high enrichment factor, and easy integration with many subsequent processes, such as separation, reaction, and extraction etc. Despite significant progress in the experimental research, fundamental understanding and detailed modeling of the preconcentration systems is still lacking. The mechanism of the electrokinetic trapping of charged particles is currently limited to the force balance analysis between the electric force and fluid drag force in an over-simplified one-dimensional (1D) model, which misses many signatures of the actual system. This letter studies the particle trapping phenomena that are not explainable in the 1D model through the calculation of the two-dimensional (2D) force fields. The trapping of charged particles is shown to significantly distort the electric field and fluid flow pattern, which in turn leads to the different trapping behaviors of particles of different sizes. The mechanisms behind the protrusions and instability of the focused band, which are important factors determining overall preconcentration efficiency, are revealed through analyzing the rotating fluxes of particles in the vicinity of the ion-selective membrane. The differences in the enrichment factors of differently sized particles are understood through the interplay between the electric force and convective fluid flow. These results provide insights into the electrokinetic concentration effect, which could facilitate the design and optimization of ICP-based preconcentration systems.

Influence of permittivity on gradient force exerted on Mie spheres.

Science.gov (United States)

Chen, Jun; Li, Kaikai; Li, Xiao

2018-04-01

In optical trapping, whether a particle could be stably trapped into the focus region greatly depends on the strength of the gradient force. Individual theoretical study on gradient force exerted on a Mie particle is rare because the mathematical separation of the gradient force and the scattering force in the Mie regime is difficult. Based on the recent forces separation work by Du et al. [Sci. Rep.7, 18042 (2017)SRCEC32045-232210.1038/s41598-017-17874-1], we investigate the influence of permittivity (an important macroscopic physical quantity) on the gradient force exerted on a Mie particle by cooperating numerical calculation using fast Fourier transform and analytical analysis using multipole expansion. It is revealed that gradient forces exerted on small spheres are mainly determined by the electric dipole moment except for certain permittivity with which the real part of polarizability of the electric dipole approaches zero, and gradient forces exerted on larger spheres are complex because of the superposition of the multipole moments. The classification of permittivity corresponding to different varying tendencies of gradient forces exerted on small spheres or larger Mie particles are illustrated. Absorption of particles favors the trapping of small spheres by gradient force, while it is bad for the trapping of larger particles. Moreover, the absolute values of the maximal gradient forces exerted on larger Mie particles decline greatly versus the varied imaginary part of permittivity. This work provides elaborate investigation on the different varying tendencies of gradient forces versus permittivity, which favors more accurate and free optical trapping.

Motion Control of Four-Wheel Independently Actuated Electric Ground Vehicles considering Tire Force Saturations

Directory of Open Access Journals (Sweden)

Rongrong Wang

2013-01-01

Full Text Available A vehicle stability control approach for four-wheel independently actuated (FWIA electric vehicles is presented. The proposed control method consists of a higher-level controller and a lower-level controller. An adaptive control-based higher-level controller is designed to yield the vehicle virtual control efforts to track the desired vehicle motions due to the possible modeling inaccuracies and parametric uncertainties. The lower-level controller considering tire force saturation is given to allocate the required control efforts to the four in-wheel motors for providing the desired tire forces. An analytic method is given to distribute the high-level control efforts, without using the numerical-optimization-based control allocation algorithms. Simulations based on a high-fidelity, CarSim, and full-vehicle model show the effectiveness of the control approach.

Metabolic costs of force generation for constant-frequency and catchlike-inducing electrical stimulation in human tibialis anterior muscle

DEFF Research Database (Denmark)

Ratkevicius, Aivaras; Quistorff, Bjørn

2002-01-01

-frequency trains, catchlike-inducing trains produced a faster force generation and were more effective in maintaining the force--time integral as well as peak force. However, ATP costs of force generation were similar for the catchlike-inducing and constant-frequency stimulation (6.7 plus/minus 1.1 and 6.6 plus......Metabolic costs of force generation were compared for constant-frequency and catchlike-inducing electrical stimulation. Repetitive catchlike-inducing trains consisted of 2 interpulse intervals (IPIs) at 12.5 ms, 1 IPI at 25 ms, and 5 IPIs at 50 ms. Constant-frequency trains consisted of 8 IPIs...... at 37.5 ms. One train was delivered to the peroneal nerve every 2.5 s for 36 times under ischemic conditions. Anaerobic adenosine triphosphate (ATP) turnover was determined using 31-phosphorus magnetic resonance spectroscopy (P-MRS) of the human tibialis anterior muscle. Compared with constant...

Low-Temperature Reduction of Graphene Oxide: Electrical Conductance and Scanning Kelvin Probe Force Microscopy

Science.gov (United States)

Slobodian, Oleksandr M.; Lytvyn, Peter M.; Nikolenko, Andrii S.; Naseka, Victor M.; Khyzhun, Oleg Yu.; Vasin, Andrey V.; Sevostianov, Stanislav V.; Nazarov, Alexei N.

2018-05-01

Graphene oxide (GO) films were formed by drop-casting method and were studied by FTIR spectroscopy, micro-Raman spectroscopy (mRS), X-ray photoelectron spectroscopy (XPS), four-points probe method, atomic force microscopy (AFM), and scanning Kelvin probe force (SKPFM) microscopy after low-temperature annealing at ambient conditions. It was shown that in temperature range from 50 to 250 °C the electrical resistivity of the GO films decreases by seven orders of magnitude and is governed by two processes with activation energies of 6.22 and 1.65 eV, respectively. It was shown that the first process is mainly associated with water and OH groups desorption reducing the thickness of the film by 35% and causing the resistivity decrease by five orders of magnitude. The corresponding activation energy is the effective value determined by desorption and electrical connection of GO flakes from different layers. The second process is mainly associated with desorption of oxygen epoxy and alkoxy groups connected with carbon located in the basal plane of GO. AFM and SKPFM methods showed that during the second process, first, the surface of GO plane is destroyed forming nanostructured surface with low work function and then at higher temperature a flat carbon plane is formed that results in an increase of the work function of reduced GO.

Electrical conduction in 7 nm wires constructed on λ-DNA

International Nuclear Information System (INIS)

Lund, John; Dong Jianchun; Deng Zhaoxiang; Mao Chengde; Parviz, Babak A

2006-01-01

We examine the morphological and electrical characteristics of nanowires fabricated on DNA templates via palladium (Pd) reduction. λ-DNA molecules were stretched and aligned on a mica surface using a molecular combing technique, followed by an electroless deposition of palladium, resulting in formation of nanowires with nominal width of 7 nm. We investigated the size distribution of nanowires with atomic force microscopy and made electrical connections to the wires by metal evaporation through multiple shadow masks. Electrical characterization of the nanowires under various bias conditions, variable temperature, and with different contact metal work functions revealed a conduction mechanism resembling that of granular metals

Electrostatic force microscopy and electrical isolation of etched few-layer graphene nano-domains

Energy Technology Data Exchange (ETDEWEB)

Hunley, D. Patrick; Sundararajan, Abhishek; Boland, Mathias J.; Strachan, Douglas R., E-mail: doug.strachan@uky.edu [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)

2014-12-15

Nanostructured bi-layer graphene samples formed through catalytic etching are investigated with electrostatic force microscopy. The measurements and supporting computations show a variation in the microscopy signal for different nano-domains that are indicative of changes in capacitive coupling related to their small sizes. Abrupt capacitance variations detected across etch tracks indicates that the nano-domains have strong electrical isolation between them. Comparison of the measurements to a resistor-capacitor model indicates that the resistance between two bi-layer graphene regions separated by an approximately 10 nm wide etch track is greater than about 1×10{sup 12} Ω with a corresponding gap resistivity greater than about 3×10{sup 14} Ω⋅nm. This extremely large gap resistivity suggests that catalytic etch tracks within few-layer graphene samples are sufficient for providing electrical isolation between separate nano-domains that could permit their use in constructing atomically thin nanogap electrodes, interconnects, and nanoribbons.

Electrostatic force microscopy and electrical isolation of etched few-layer graphene nano-domains

International Nuclear Information System (INIS)

Hunley, D. Patrick; Sundararajan, Abhishek; Boland, Mathias J.; Strachan, Douglas R.

2014-01-01

Nanostructured bi-layer graphene samples formed through catalytic etching are investigated with electrostatic force microscopy. The measurements and supporting computations show a variation in the microscopy signal for different nano-domains that are indicative of changes in capacitive coupling related to their small sizes. Abrupt capacitance variations detected across etch tracks indicates that the nano-domains have strong electrical isolation between them. Comparison of the measurements to a resistor-capacitor model indicates that the resistance between two bi-layer graphene regions separated by an approximately 10 nm wide etch track is greater than about 1×10 12  Ω with a corresponding gap resistivity greater than about 3×10 14  Ω⋅nm. This extremely large gap resistivity suggests that catalytic etch tracks within few-layer graphene samples are sufficient for providing electrical isolation between separate nano-domains that could permit their use in constructing atomically thin nanogap electrodes, interconnects, and nanoribbons

Comparison of several algorithms of the electric force calculation in particle plasma models

International Nuclear Information System (INIS)

Lachnitt, J; Hrach, R

2014-01-01

This work is devoted to plasma modelling using the technique of molecular dynamics. The crucial problem of most such models is the efficient calculation of electric force. This is usually solved by using the particle-in-cell (PIC) algorithm. However, PIC is an approximative algorithm as it underestimates the short-range interactions of charged particles. We propose a hybrid algorithm which adds these interactions to PIC. Then we include this algorithm in a set of algorithms which we test against each other in a two-dimensional collisionless magnetized plasma model. Besides our hybrid algorithm, this set includes two variants of pure PIC and the direct application of Coulomb's law. We compare particle forces, particle trajectories, total energy conservation and the speed of the algorithms. We find out that the hybrid algorithm can be a good replacement of direct Coulomb's law application (quite accurate and much faster). It is however probably unnecessary to use it in practical 2D models.

Electrical characterization of grain boundaries of CZTS thin films using conductive atomic force microscopy techniques

Energy Technology Data Exchange (ETDEWEB)

Muhunthan, N.; Singh, Om Pal [Compound Semiconductor Solar Cell, Physics of Energy Harvesting Division, New Delhi 110012 (India); Toutam, Vijaykumar, E-mail: toutamvk@nplindia.org [Quantum Phenomena and Applications Division, CSIR-National Physical Laboratory, Dr. K.S. Krishnan Marg, New Delhi 110012 (India); Singh, V.N., E-mail: singhvn@nplindia.org [Compound Semiconductor Solar Cell, Physics of Energy Harvesting Division, New Delhi 110012 (India)

2015-10-15

Graphical abstract: Experimental setup for conducting AFM (C-AFM). - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) thin film was grown by reactive co-sputtering. • The electronic properties were probed using conducting atomic force microscope, scanning Kelvin probe microscopy and scanning capacitance microscopy. • C-AFM current flow mainly through grain boundaries rather than grain interiors. • SKPM indicated higher potential along the GBs compared to grain interiors. • The SCM explains that charge separation takes place at the interface of grain and grain boundary. - Abstract: Electrical characterization of grain boundaries (GB) of Cu-deficient CZTS (Copper Zinc Tin Sulfide) thin films was done using atomic force microscopic (AFM) techniques like Conductive atomic force microscopy (CAFM), Kelvin probe force microscopy (KPFM) and scanning capacitance microscopy (SCM). Absorbance spectroscopy was done for optical band gap calculations and Raman, XRD and EDS for structural and compositional characterization. Hall measurements were done for estimation of carrier mobility. CAFM and KPFM measurements showed that the currents flow mainly through grain boundaries (GB) rather than grain interiors. SCM results showed that charge separation mainly occurs at the interface of grain and grain boundaries and not all along the grain boundaries.

A quantitative overview of biophysical forces impinging on neural function

International Nuclear Information System (INIS)

Mueller, Jerel K; Tyler, William J

2014-01-01

The fundamentals of neuronal membrane excitability are globally described using the Hodgkin-Huxley (HH) model. The HH model, however, does not account for a number of biophysical phenomena associated with action potentials or propagating nerve impulses. Physical mechanisms underlying these processes, such as reversible heat transfer and axonal swelling, have been compartmentalized and separately investigated to reveal neuronal activity is not solely influenced by electrical or biochemical factors. Instead, mechanical forces and thermodynamics also govern neuronal excitability and signaling. To advance our understanding of neuronal function and dysfunction, compartmentalized analyses of electrical, chemical, and mechanical processes need to be revaluated and integrated into more comprehensive theories. The present perspective is intended to provide a broad overview of biophysical forces that can influence neural function, but which have been traditionally underappreciated in neuroscience. Further, several examples where mechanical forces have been shown to exert their actions on nervous system development, signaling, and plasticity are highlighted to underscore their importance in sculpting neural function. By considering the collective actions of biophysical forces influencing neuronal activity, our working models can be expanded and new paradigms can be applied to the investigation and characterization of brain function and dysfunction. (topical review)

The electrical network of maize root apex is gravity dependent.

Science.gov (United States)

Masi, Elisa; Ciszak, Marzena; Comparini, Diego; Monetti, Emanuela; Pandolfi, Camilla; Azzarello, Elisa; Mugnai, Sergio; Baluška, Frantisek; Mancuso, Stefano

2015-01-15

Investigations carried out on maize roots under microgravity and hypergravity revealed that gravity conditions have strong effects on the network of plant electrical activity. Both the duration of action potentials (APs) and their propagation velocities were significantly affected by gravity. Similarly to what was reported for animals, increased gravity forces speed-up APs and enhance synchronized electrical events also in plants. The root apex transition zone emerges as the most active, as well as the most sensitive, root region in this respect.

Electrical anisotropy properties of ZnO nanorods analyzed by conductive atomic force microscopy

International Nuclear Information System (INIS)

Wu Yunfeng; Yu Naisen; Liu Dongping; He Yangyang; Liu Yuanda; Liang Hongwei; Du Guotong

2013-01-01

Highlights: ► The electrical properties of one individual lying ZnO nanorod were performed by C-AFM measurement. ► Inhomogeneous spatial current distribution was detected. ► Current was detected along the side facets while no current was detected in the top plane for ZnO nanorod. ► The side facets were more conductive than the top facets of ZnO nanorods. - Abstract: In this study, we have prepared ZnO nanorods on cracked GaN substrates using aqueous solution method. Unique electrical characterization of one individual lying ZnO nanorod is analyzed by conductive atomic force microscopy (C-AFM). Effect of anisotropy properties on the conductivity of a single nanorod has been investigated. The current maps of ZnO nanorods have been simultaneously recorded with the topography which is gained by AFM-contact mode. The C-AFM measurement present local current–voltage (I–V) characteristics of the side facets of one individual lying nanorod, however, no current is detected on the top facets of ZnO nanorods. Measurement results indicate that the side facets are more electrically active than the top facets of ZnO nanorods due to lower Schottky barrier height of the side facets.

Forced-rupture of cell-adhesion complexes reveals abrupt switch between two brittle states

Science.gov (United States)

Toan, Ngo Minh; Thirumalai, D.

2018-03-01

Cell adhesion complexes (CACs), which are activated by ligand binding, play key roles in many cellular functions ranging from cell cycle regulation to mediation of cell extracellular matrix adhesion. Inspired by single molecule pulling experiments using atomic force spectroscopy on leukocyte function-associated antigen-1 (LFA-1), expressed in T-cells, bound to intercellular adhesion molecules (ICAM), we performed constant loading rate (rf) and constant force (F) simulations using the self-organized polymer model to describe the mechanism of ligand rupture from CACs. The simulations reproduce the major experimental finding on the kinetics of the rupture process, namely, the dependence of the most probable rupture forces (f*s) on ln rf (rf is the loading rate) exhibits two distinct linear regimes. The first, at low rf, has a shallow slope, whereas the slope at high rf is much larger, especially for a LFA-1/ICAM-1 complex with the transition between the two occurring over a narrow rf range. Locations of the two transition states (TSs) extracted from the simulations show an abrupt change from a high value at low rf or constant force, F, to a low value at high rf or F. This unusual behavior in which the CACs switch from one brittle (TS position is a constant over a range of forces) state to another brittle state is not found in forced-rupture in other protein complexes. We explain this novel behavior by constructing the free energy profiles, F(Λ)s, as a function of a collective reaction coordinate (Λ), involving many key charged residues and a critical metal ion (Mg2+). The TS positions in F(Λ), which quantitatively agree with the parameters extracted using the Bell-Evans model, change abruptly at a critical force, demonstrating that it, rather than the molecular extension, is a good reaction coordinate. Our combined analyses using simulations performed in both the pulling modes (constant rf and F) reveal a new mechanism for the two loading regimes observed in the

Lienard-Wiechert field as covariant dynamics of electric lines of force

International Nuclear Information System (INIS)

Arutyunyan, S.G.

1989-01-01

The Lienard-Wiechert field of an arbitrarily moving charge is presented as a system of Lorentz-covariant moving electric lines of force. It is shown that the 4-vector describing these lines is written as a sum of the 4-vector of the charge and the isotropic 4-vector directed to the observation point. The motion of this 4-vector is described by the equation coinciding with the equation of motion for magnetic moment in external fields provided that the intrinsic magnetic moment is zero. By the system of lines that corresponds to the complete equation of magnetic moment in external fields the electromagnetic field is restored. It turned out that the spatial magnetic current proportional to the isotropic 4-vector directed to the observation point corresponds to this field. 8 refs

Forces that direct the competition in the electric power industry in the new institutional scenery

International Nuclear Information System (INIS)

Ribeiro Filho, Ary Pinto; Moraes, Walter Fernando Araujo de

1999-01-01

This work identifies the probable strategic characteristics of the interconnected North-Northeast Brazilian electricity industry, after the current restructuring and privatization process has been implemented. It is a 15.0 thousand MW generation industry supplying more than 33.5 million consumers. The normative scenery for analysis of the electricity industry takes into consideration the premises that the government establishes the vertical separation of generation, transmission, distribution and retailing, and introduces the regulation to a competitive industrial structure in generation and retailing. It is assumed that free access to transmit and distribute electricity and broad choices for consumers are the main features for competition in both generation and retailing. The essence of formulating strategy is to relate a company with its environment, considering the industrial structure. Porter's five forces model for industry environment and competition, emphasizing the role of the government in such regulated industry, is the basic theoretical reference. The main strategic characteristics related to entry barriers, rivalry intensity, supplier power, customer power and substitute products are analyzed. (author)

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Effects of electric field and Coriolis force on electrohydrodynamic stability of poorly conducting couple stress parallel fluid flow in a channel

International Nuclear Information System (INIS)

Shankar, B.M.; Rudraiah, N.

2013-01-01

The effective functioning of microfluidic devices in chemical, electrical and mechanical engineering involving fluidics particularly those having vibrations and petroleum products containing organic, inorganic and other microfluidics require understanding and control of stability of poorly conducting parallel fluid flows. The electrical conductivity, σ, of a poorly conducting fluidics, increases with the temperature and the concentration of freely suspended particles like RBC, WBC and so on in the blood, the hylauronic acid (HA) and nutrients of synovial fluid in synovial joints will spin producing microrotation, forming micropolar fluid of Eringen. The presence of Deuterium - Tritium (DT) in inertial fusion target (IFT) may also be modeled using micropolar fluid theory of Eringen. A particular case of micropolar fluid theory when microrotation balances with the natural vorticity of a poorly conducting fluidics in the presence of an electric field is called ‘electrohydrodynamic couple stress fluid’ (EHDCF). These EHDCFs exhibit a variation of electrical conductivity, ∇ σ, increasing with temperature and concentration of freely suspended particles, releases the charges from the nuclei forming distribution of charge density, ρ e . These charges induce an electric field, 1 E i . If need be, we can apply an electric field, 1 E a , by embedding electrodes of different potentials at the boundaries. The total electric field, 1 E = 1 E i + 1 E a , produces a current density, 1 J = ρ σ 1 E, according to Ohm’s law and also produces an electric force, 1 F σ = σ 1 E. This current 1 J acts as sensing and the force, 1 F σ acts as actuation. These two properties make the poorly conducting couple stress fluid to act as a smart material. The objective of this paper is to show that EHDCV in presence of coriolis force plays a significant role in controlling the stability of parallel flows which is essential for an effective functioning of machineries that occur in

MAGNETIC VERSUS ELECTRICAL STIMULATION IN THE INTERPOLATION TWITCH TECHNIQUE OF ELBOW FLEXORS

Directory of Open Access Journals (Sweden)

Sofia I. Lampropoulou

2012-12-01

Full Text Available The study compared peripheral magnetic with electrical stimulation of the biceps brachii m. (BB in the single pulse Interpolation Twitch Technique (ITT. 14 healthy participants (31±7 years participated in a within-subjects repeated-measures design study. Single, constant-current electrical and magnetic stimuli were delivered over the motor point of BB with supramaximal intensity (20% above maximum at rest and at various levels of voluntary contraction. Force measurements from right elbow isometric flexion and muscle electromyograms (EMG from the BB, the triceps brachii m. (TB and the abductor pollicis brevis m. (APB were obtained. The twitch forces at rest and maximal contractions, the twitch force-voluntary force relationship, the M-waves and the voluntary activation (VA of BB between magnetic and electrical stimulation were compared. The mean amplitude of the twitches evoked at MVC was not significantly different between electrical (0.62 ± 0.49 N and magnetic (0.81 ± 0.49 N stimulation (p > 0.05, and the maximum VA of BB was comparable between electrical (95% and magnetic (93% stimulation (p > 0. 05. No differences (p >0.05 were revealed in the BB M-waves between electrical (13.47 ± 0.49 mV.ms and magnetic (12.61 ± 0.58 mV.ms stimulation. The TB M-waves were also similar (p > 0.05 but electrically evoked APB M-waves were significantly larger than those evoked by magnetic stimulation (p < 0.05. The twitch-voluntary force relationship over the range of MVCs was best described by non-linear functions for both electrical and magnetic stimulation. The electrically evoked resting twitches were consistently larger in amplitude than the magnetically evoked ones (mean difference 3.1 ± 3.34 N, p < 0.05. Reduction of the inter-electrodes distance reduced the twitch amplitude by 6.5 ± 6.2 N (p < 0.05. The fundamental similarities in voluntary activation assessment of BB with peripheral electrical and magnetic stimulation point towards a promising

Fire protection electrical engineering

International Nuclear Information System (INIS)

Oh, Jung Min

2000-03-01

This book concentrates of electricity with current, voltage, power, ohms law, access of resistance, electrolytic analysis and battery, static on frictional electricity and electrostatic induction, coulomb's law, Gauss's law, condenser and capacity, magmatism on magnetic field and magnetic line of force, magnetic circuit, electromagnetic force, electromotive current, basic alternating current circuit, circuit network analysis, three-phase current, non-sinusoidal alternating current, transient phenomena, semiconductor, electric measurement on measurement over resistance, power, power rate and circuit tester, automatic control on introduction, term, classification, foundation of sequence control, logic circuit and basic logic circuit and electric equipment.

Novel parallel plate condenser for single particle electrostatic force measurements in atomic force microscope

KAUST Repository

Kwek, Jin Wang

2011-07-01

A combination of small parallel plate condenser with Indium Tin Oxide (ITO) glass slides as electrodes and an atomic force microscope (AFM) is used to characterize the electrostatic behavior of single glass bead microparticles (105-150 μm) glued to the AFM cantilever. This novel setup allows measurements of the electrostatic forces acting on a particle in an applied electrical field to be performed in ambient air conditions. By varying the position of the microparticle between the electrodes and the strength of the applied electric field, the relative contributions of the particle net charge, induced and image charges were investigated. When the microparticle is positioned in the middle of the electrodes, the force acting on the microparticle was linear with the applied electric field and proportional to the microparticle net charge. At distances close to the bottom electrode, the force follows a parabolic relationship with the applied electric field reflecting the contributions of induced and image charges. The method can be used for the rapid evaluation of the charging and polarizability properties of the microparticle as well as an alternative to the conventional Faraday\\'s pail technique. © 2011 Elsevier B.V.

Physics investigate the forces of nature

CERN Document Server

Gardner, Jane

2014-01-01

Have you ever noticed that the physical world works in certain ways? Skateboarders use force and motion to perform tricks. If you jump up as high as you can, you'll quickly fall back to the ground. Baseball players use gravity to bring the ball back down when they throw it. When you flip a switch, electricity powers your toaster. Rock bands use electricity to put on a show. The fascinating science of physics helps you understand why forces, motion, gravity, electricity, light, and sound work in predictable ways. Combining inquiry-based activities with physics topics, Physics: Investigate the Forces of Nature features graphic novel illustrations, fascinating sidebars, youtube links, and a glossary of important vocabulary to illuminate the complex world of physics and bring it to life. Projects include designing a skateboard park that maps the forces at work on the skateboarder and the skateboard, and creating a stage design for a rock band that places electric current where it is needed. Additional materials i...

Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study

Energy Technology Data Exchange (ETDEWEB)

Lesoil, Charles [Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226-8501 (Japan); Nonaka, Takahiro [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Sekiguchi, Hiroshi; Osada, Toshiya [Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226-8501 (Japan); Miyata, Makoto [Department of Biology, Graduate School of Science, Osaka City University, Sumiyoshi-ku, Osaka 558-8585 (Japan); Afrin, Rehana [Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226-8501 (Japan); Biofrontier Center, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226-8501 (Japan); Ikai, Atsushi, E-mail: ikai.a.aa@m.titech.ac.jp [Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsutacho 4259, Midori-ku, Yokohama 226-8501 (Japan)

2010-01-15

Recent studies of the gliding bacteria Mycoplasma mobile have identified a family of proteins called the Gli family which was considered to be involved in this novel and yet fairly unknown motility system. The 349 kDa protein called Gli349 was successfully isolated and purified from the bacteria, and electron microscopy imaging and antibody experiments led to the hypothesis that it acts as the 'leg' of M. mobile, responsible for attachment to the substrate as well as for gliding motility. However, more precise evidence of the molecular shape and function of this protein was required to asses this theory any further. In this study, an atomic force microscope (AFM) was used both as an imaging and a force measurement device to provide new information about Gli349 and its role in gliding motility. AFM images of the protein were obtained revealing a complex structure with both rigid and flexible parts, consistent with previous electron micrographs of the protein. Single-molecular force spectroscopy experiments were also performed, revealing that Gli349 is able to specifically bind to sialyllactose molecules and withstand unbinding forces around 70 pN. These findings strongly support the idea that Gli349 is the 'leg' protein of M. mobile, responsible for binding and also most probably force generation during gliding motility.

Cell-Targeted Optogenetics and Electrical Microstimulation Reveal the Primate Koniocellular Projection to Supra-granular Visual Cortex.

Science.gov (United States)

Klein, Carsten; Evrard, Henry C; Shapcott, Katharine A; Haverkamp, Silke; Logothetis, Nikos K; Schmid, Michael C

2016-04-06

Electrical microstimulation and more recently optogenetics are widely used to map large-scale brain circuits. However, the neuronal specificity achieved with both methods is not well understood. Here we compare cell-targeted optogenetics and electrical microstimulation in the macaque monkey brain to functionally map the koniocellular lateral geniculate nucleus (LGN) projection to primary visual cortex (V1). Selective activation of the LGN konio neurons with CamK-specific optogenetics caused selective electrical current inflow in the supra-granular layers of V1. Electrical microstimulation targeted at LGN konio layers revealed the same supra-granular V1 activation pattern as the one elicited by optogenetics. Taken together, these findings establish a selective koniocellular LGN influence on V1 supra-granular layers, and they indicate comparable capacities of both stimulation methods to isolate thalamo-cortical circuits in the primate brain. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrical characterization of Ge–Sb–Te phase change nano-pillars using conductive atomic force microscopy

International Nuclear Information System (INIS)

Bae, Byeong-Ju; Hong, Sung-Hoon; Hwang, Seon-Yong; Hwang, Jae-Yeon; Yang, Ki-Yeon; Lee, Heon

2009-01-01

The electrical characteristic of phase change material was studied in nano-scale using nanoimprint lithography and a conducting atomic force microscopy measurement system. Nanoimprint lithography was used to fabricate the nano-scale phase change material pattern. A Pt-coated AFM tip was used as a top electrode to measure the electrical characteristics of the GST nano-pillar. The GST nano-pillar, which is 200 nm in diameter, was amorphized by 2 V and 5 ns reset pulse and was then brought back to the crystalline phase by applying 1.3 V and 150 ns set pulse. Using this measurement system, the GST nano-pillar was switched between the amorphous and crystalline phases more than five times. The results of the reset and the set current measurement with the GST nano-pillar sizes show that the reset and the set currents also decreased with the decrease of the GST pillar size

Ambiguities on electric and magnetic fields for an extended gauge model

International Nuclear Information System (INIS)

Colatto, L.P.; Doria, R.M.

1990-01-01

Generalized electric and magnetic fields in a system containing N-potential fields in the same U (1) - group are obtained. Bianchi identities, equations of motions, conserved charges and Lorentz forces are developed in association to each of these fields. Such facts confirm that the same parameter α (x) is able to organize the presence of distinct fields. The physics generated from the minimal action principle is independent of the initial definition for the electric (magnetic) field. Nevertheless, such a choice reveals differences in the Bianchi identity context. (author)

An electric field in a gravitational field

International Nuclear Information System (INIS)

Harpaz, Amos

2005-01-01

The behaviour of an electric field in a gravitational field is analysed. It is found that due to the mass (energy) of the electric field, it is subjected to gravity and it falls in the gravitational field. This fall curves the electric field, a stress force (a reaction force) is created, and the interaction of this reaction force with the static charge gives rise to the creation of radiation

Electrical Double-Layer and Ion Bridging Forces between Symmetric and Asymmetric Charged Surfaces in the Presence of Mono- and Divalent Ions

DEFF Research Database (Denmark)

Liu, Xiaoyan; Feilberg, Karen Louise; Yan, Wei

2017-01-01

charged (3-aminopropyl)trimethoxysilane, and the negatively charged (3-mercaptopropyl)trimethoxysilane. The interactions between the three symmetric systems, as well as between the three asymmetric combinations of surfaces, were measured and compared to calculated electrical double-layer forces...

Integrated Analysis of Contractile Kinetics, Force Generation, and Electrical Activity in Single Human Stem Cell-Derived Cardiomyocytes

Directory of Open Access Journals (Sweden)

Jan David Kijlstra

2015-12-01

Full Text Available The quantitative analysis of cardiomyocyte function is essential for stem cell-based approaches for the in vitro study of human cardiac physiology and pathophysiology. We present a method to comprehensively assess the function of single human pluripotent stem cell-derived cardiomyocyte (hPSC-CMs through simultaneous quantitative analysis of contraction kinetics, force generation, and electrical activity. We demonstrate that statistical analysis of movies of contracting hPSC-CMs can be used to quantify changes in cellular morphology over time and compute contractile kinetics. Using a biomechanical model that incorporates substrate stiffness, we calculate cardiomyocyte force generation at single-cell resolution and validate this approach with conventional traction force microscopy. The addition of fluorescent calcium indicators or membrane potential dyes allows the simultaneous analysis of contractility and calcium handling or action potential morphology. Accordingly, our approach has the potential for broad application in the study of cardiac disease, drug discovery, and cardiotoxicity screening.

The effect of electric field geometry on the performance of electromembrane extraction systems: Footprints of a third driving force along with migration and diffusion

Energy Technology Data Exchange (ETDEWEB)

Moazami, Hamid Reza [School of Physics and Accelerators, NSTRI, P. O. Box, 11365-8486, Tehran (Iran, Islamic Republic of); Hosseiny Davarani, Saied Saeed, E-mail: ss-hosseiny@sbu.ac.ir [Faculty of Chemistry, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of); Mohammadi, Jamil; Nojavan, Saeed [Faculty of Chemistry, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of); Abrari, Masoud [Laser and Plasma Research Institute, Shahid Beheshti University, G. C., 1983963113, Evin, Tehran (Iran, Islamic Republic of)

2015-09-03

The distribution of electric field vectors was first calculated for electromembrane extraction (EME) systems in classical and cylindrical electrode geometries. The results showed that supported liquid membrane (SLM) has a general field amplifying effect due to its lower dielectric constant in comparison with aqueous donor/acceptor solutions. The calculated norms of the electric field vector showed that a DC voltage of 50 V can create huge electric field strengths up to 64 kV m{sup −1} and 111 kV m{sup −1} in classical and cylindrical geometries respectively. In both cases, the electric field strength reached its peak value on the inner wall of the SLM. In the case of classical geometry, the field strength was a function of the polar position of the SLM whereas the field strength in cylindrical geometry was angularly uniform. In order to investigate the effect of the electrode geometry on the performance of real EME systems, the analysis was carried out in three different geometries including classical, helical and cylindrical arrangements using naproxen and sodium diclofenac as the model analytes. Despite higher field strength and extended cross sectional area, the helical and cylindrical geometries gave lower recoveries with respect to the classical EME. The observed decline of the signal was proved to be against the relations governing migration and diffusion processes, which means that a third driving force is involved in EME. The third driving force is the interaction between the radially inhomogeneous electric field and the analyte in its neutral form. - Highlights: • Electric field vectors have been calculated in EME systems. • A new driving force has been proposed in EME systems. • EME can be theoretically applied to nonionic polarizable analytes.

The effect of electric field geometry on the performance of electromembrane extraction systems: Footprints of a third driving force along with migration and diffusion

International Nuclear Information System (INIS)

Moazami, Hamid Reza; Hosseiny Davarani, Saied Saeed; Mohammadi, Jamil; Nojavan, Saeed; Abrari, Masoud

2015-01-01

The distribution of electric field vectors was first calculated for electromembrane extraction (EME) systems in classical and cylindrical electrode geometries. The results showed that supported liquid membrane (SLM) has a general field amplifying effect due to its lower dielectric constant in comparison with aqueous donor/acceptor solutions. The calculated norms of the electric field vector showed that a DC voltage of 50 V can create huge electric field strengths up to 64 kV m −1 and 111 kV m −1 in classical and cylindrical geometries respectively. In both cases, the electric field strength reached its peak value on the inner wall of the SLM. In the case of classical geometry, the field strength was a function of the polar position of the SLM whereas the field strength in cylindrical geometry was angularly uniform. In order to investigate the effect of the electrode geometry on the performance of real EME systems, the analysis was carried out in three different geometries including classical, helical and cylindrical arrangements using naproxen and sodium diclofenac as the model analytes. Despite higher field strength and extended cross sectional area, the helical and cylindrical geometries gave lower recoveries with respect to the classical EME. The observed decline of the signal was proved to be against the relations governing migration and diffusion processes, which means that a third driving force is involved in EME. The third driving force is the interaction between the radially inhomogeneous electric field and the analyte in its neutral form. - Highlights: • Electric field vectors have been calculated in EME systems. • A new driving force has been proposed in EME systems. • EME can be theoretically applied to nonionic polarizable analytes.

Visualized Multiprobe Electrical Impedance Measurements with STM Tips Using Shear Force Feedback Control

Directory of Open Access Journals (Sweden)

Luis Botaya

2016-05-01

Full Text Available Here we devise a multiprobe electrical measurement system based on quartz tuning forks (QTFs and metallic tips capable of having full 3D control over the position of the probes. The system is based on the use of bent tungsten tips that are placed in mechanical contact (glue-free solution with a QTF sensor. Shear forces acting in the probe are measured to control the tip-sample distance in the Z direction. Moreover, the tilting of the tip allows the visualization of the experiment under the optical microscope, allowing the coordination of the probes in X and Y directions. Meanwhile, the metallic tips are connected to a current–voltage amplifier circuit to measure the currents and thus the impedance of the studied samples. We discuss here the different aspects that must be addressed when conducting these multiprobe experiments, such as the amplitude of oscillation, shear force distance control, and wire tilting. Different results obtained in the measurement of calibration samples and microparticles are presented. They demonstrate the feasibility of the system to measure the impedance of the samples with a full 3D control on the position of the nanotips.

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

Metagenomic analyses reveal the involvement of syntrophic consortia in methanol/electricity conversion in microbial fuel cells.

Science.gov (United States)

Yamamuro, Ayaka; Kouzuma, Atsushi; Abe, Takashi; Watanabe, Kazuya

2014-01-01

Methanol is widely used in industrial processes, and as such, is discharged in large quantities in wastewater. Microbial fuel cells (MFCs) have the potential to recover electric energy from organic pollutants in wastewater; however, the use of MFCs to generate electricity from methanol has not been reported. In the present study, we developed single-chamber MFCs that generated electricity from methanol at the maximum power density of 220 mW m(-2) (based on the projected area of the anode). In order to reveal how microbes generate electricity from methanol, pyrosequencing of 16S rRNA-gene amplicons and Illumina shotgun sequencing of metagenome were conducted. The pyrosequencing detected in abundance Dysgonomonas, Sporomusa, and Desulfovibrio in the electrolyte and anode and cathode biofilms, while Geobacter was detected only in the anode biofilm. Based on known physiological properties of these bacteria, it is considered that Sporomusa converts methanol into acetate, which is then utilized by Geobacter to generate electricity. This speculation is supported by results of shotgun metagenomics of the anode-biofilm microbes, which reconstructed relevant catabolic pathways in these bacteria. These results suggest that methanol is anaerobically catabolized by syntrophic bacterial consortia with electrodes as electron acceptors.

Electronic zero-point fluctuation forces inside circuit components

Science.gov (United States)

Leonhardt, Ulf

2018-01-01

One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies. PMID:29719863

Electronic zero-point fluctuation forces inside circuit components.

Science.gov (United States)

Shahmoon, Ephraim; Leonhardt, Ulf

2018-04-01

One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies.

Study of Dynamic Membrane Behavior in Applied DC Electric Field

Science.gov (United States)

Dutta, Prashanta; Morshed, Adnan; Hossan, Mohammad

2017-11-01

Electrodeformation of vesicles can be used as a useful tool to understand the characteristics of biological soft matter, where vesicles immersed in a fluid medium are subjected to an applied electric field. The complex response of the vesicle membrane strongly depends on the conductivity of surrounding fluid, vesicle size and shape, and applied electric field We studied the electrodeformation of vesicles immersed in a fluid media under a short DC electric pulse. An immersed interface method is used to solve the electric field over the domain with conductive or non-conductive vesicles while an immersed boundary scheme is employed to solve fluid flow, fluid-solid interaction, membrane mechanics and vesicle movement. Force analysis on the membrane surface reveals almost linear relation with vesicle size, but highly nonlinear influence of applied field as well as the conductivity ratios inside and outside of the vesicle. Results also point towards an early linear deformation regime followed by an equilibrium stage for the membranes. Moreover, significant influence of the initial aspect ratio of the vesicle on the force distribution is observed across a range of conductivity ratios. Research reported in this publication was supported by the National Institute of General Medical Sciences of the National Institutes of Health under Award Number R01GM122081.

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…

Active mechanics in living oocytes reveal molecular-scale force kinetics

Science.gov (United States)

Ahmed, Wylie; Fodor, Etienne; Almonacid, Maria; Bussonnier, Matthias; Verlhac, Marie-Helene; Gov, Nir; Visco, Paolo; van Wijland, Frederic; Betz, Timo

Unlike traditional materials, living cells actively generate forces at the molecular scale that change their structure and mechanical properties. This nonequilibrium activity is essential for cellular function, and drives processes such as cell division. Single molecule studies have uncovered the detailed force kinetics of isolated motor proteins in-vitro, however their behavior in-vivo has been elusive due to the complex environment inside the cell. Here, we quantify active forces and intracellular mechanics in living oocytes using in-vivo optical trapping and laser interferometry of endogenous vesicles. We integrate an experimental and theoretical framework to connect mesoscopic measurements of nonequilibrium properties to the underlying molecular- scale force kinetics. Our results show that force generation by myosin-V drives the cytoplasmic-skeleton out-of-equilibrium (at frequencies below 300 Hz) and actively softens the environment. In vivo myosin-V activity generates a force of F ~ 0 . 4 pN, with a power-stroke of length Δx ~ 20 nm and duration τ ~ 300 μs, that drives vesicle motion at vv ~ 320 nm/s. This framework is widely applicable to characterize living cells and other soft active materials.

Electric engineering introduction

International Nuclear Information System (INIS)

An, Byeong Won; Eom, Sang Ho

1999-03-01

It is divided into nine chapters, which includes electricity theory such as structure of material and current, nature of electricity, static, magnetic force and magnetic attraction, attraction of current and a storage battery, electric circuit on a direct current circuit, single phase circuit and 3-phase current circuit electricity machine like DC generator, DC motor, alternator, electric transformer, single-phase induction motor, 3-phase induction motor, synchronous motor, synchro electric machine, semiconductor such as diode, transistor, FET, UJT, silicon symmetrical switch, electronic circuit like smoothing circuit and Bistable MV. circuit, automatic control, measurement of electricity, electric application and safety.

Metagenomic analyses reveal the involvement of syntrophic consortia in methanol/electricity conversion in microbial fuel cells.

Directory of Open Access Journals (Sweden)

Ayaka Yamamuro

Full Text Available Methanol is widely used in industrial processes, and as such, is discharged in large quantities in wastewater. Microbial fuel cells (MFCs have the potential to recover electric energy from organic pollutants in wastewater; however, the use of MFCs to generate electricity from methanol has not been reported. In the present study, we developed single-chamber MFCs that generated electricity from methanol at the maximum power density of 220 mW m(-2 (based on the projected area of the anode. In order to reveal how microbes generate electricity from methanol, pyrosequencing of 16S rRNA-gene amplicons and Illumina shotgun sequencing of metagenome were conducted. The pyrosequencing detected in abundance Dysgonomonas, Sporomusa, and Desulfovibrio in the electrolyte and anode and cathode biofilms, while Geobacter was detected only in the anode biofilm. Based on known physiological properties of these bacteria, it is considered that Sporomusa converts methanol into acetate, which is then utilized by Geobacter to generate electricity. This speculation is supported by results of shotgun metagenomics of the anode-biofilm microbes, which reconstructed relevant catabolic pathways in these bacteria. These results suggest that methanol is anaerobically catabolized by syntrophic bacterial consortia with electrodes as electron acceptors.

Interrelation between striction forces in dielectrics and optically induced forces in transparent media

International Nuclear Information System (INIS)

Torchigin, V P; Torchigin, A V

2012-01-01

Optically induced forces applied to a transparent optical medium, which is inserted in a closed plane optical resonator, are calculated by means of an analysis of the changes in the eigenfrequency and energy stored in the resonator at various positions of the medium. These forces are compared with striction forces applied to the medium considered as a dielectric placed in an alternate electrical field within the resonator. It is shown that the optically induced forces are equal to the striction forces. The results of using the classical formula for striction forces in electrostatics are considered. (paper)

Electrical actuation of dielectric droplets

International Nuclear Information System (INIS)

Kumari, N; Bahadur, V; Garimella, S V

2008-01-01

Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-a-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets; however, the actuation of dielectric droplets has remained relatively unexplored, despite the advantages associated with the use of a dielectric droplet. This paper presents modeling and experimental results on the electrical actuation of dielectric droplets between two flat plates. A first-order analytical model, based on the energy-minimization principle, is developed to estimate the electrical actuation force on a dielectric droplet as it moves between two flat plates. Two versions of this analytical model are benchmarked for their suitability and accuracy against a detailed numerical model. The actuation force prediction is then combined with available semi-analytical expressions for predicting the forces opposing droplet motion to develop a model that predicts transient droplet motion under electrical actuation. Electrical actuation of dielectric droplets is experimentally demonstrated by moving transformer oil droplets between two flat plates under the influence of an actuation voltage. Droplet velocities and their dependence on the plate spacing and the applied voltage are experimentally measured and showed reasonable agreement with predictions from the models developed

Economic Growth, Electricity Consumption, Labor Force and Capital Input: A More Comprehensive Analysis on North China Using Panel Data

Directory of Open Access Journals (Sweden)

Huiru Zhao

2016-10-01

Full Text Available Over the past three decades, China’s economy has witnessed remarkable growth, with an average annual growth rate over 9%. However, China also faces great challenges to balance this spectacular economic growth and continuously increasing energy use like many other economies in the world. With the aim of designing effective energy and environmental policies, policymakers are required to master the relationship between energy consumption and economic growth. Therefore, in the case of North China, a multivariate model employing panel data analysis method based on the Cobb-Douglas production function which introduces electricity consumption as a main factor was established in this paper. The equilibrium relationship and causal relationship between real GDP, electricity consumption, total investment in fixed assets, and the employment were explored using data during the period of 1995–2014 for six provinces in North China, including Beijing City, Tianjin City, Hebei Province, Shanxi Province, Shandong Province and Inner Mongolia. The results of panel co-integration tests clearly state that all variables are co-integrated in the long term. Finally, Granger causality tests were used to examine the causal relationship between economic growth, electricity consumption, labor force and capital. From the Granger causality test results, we can draw the conclusions that: (1 There exist bi-directional causal relationships between electricity consumption and real GDP in six provinces except Hebei; and (2 there is a bi-directional relationship between capital input and economic growth and between labor force input and economic growth except Beijing and Hebei. Therefore, the ways to solve the contradiction of economic growth and energy consumption in North China are to reduce fossil energy consumption, develop renewable and sustainable energy sources, improve energy efficiency, and increase the proportion of the third industry, especially the sectors which

Determining concentration depth profiles in fluorinated networks by means of electric force microscopy

International Nuclear Information System (INIS)

Miccio, Luis A.; Kummali, Mohammed M.; Alegria, Angel; Montemartini, Pablo E.; Oyanguren, Patricia A.; Schwartz, Gustavo A.; Colmenero, Juan

2011-01-01

By means of electric force microscopy, composition depth profiles were measured with nanometric resolution for a series of fluorinated networks. By mapping the dielectric permittivity along a line going from the surface to the bulk, we were able to experimentally access to the fluorine concentration profile. Obtained data show composition gradient lengths ranging from 30 nm to 80 nm in the near surface area for samples containing from 0.5 to 5 wt. % F, respectively. In contrast, no gradients of concentration were detected in bulk. This method has several advantages over other techniques because it allows profiling directly on a sectional cut of the sample. By combining the obtained results with x-ray photoelectron spectroscopy measurements, we were also able to quantify F/C ratio as a function of depth with nanoscale resolution.

Effects of electric field and Coriolis force on electrohydrodynamic stability of poorly conducting couple stress parallel fluid flow in a channel

International Nuclear Information System (INIS)

Shankar, B.M.; Rudraiah, N.

2013-01-01

The linear stability of electrohydrodynamic poorly conducting couple stress viscous parallel fluid flow in a channel is studied in the presence of a non-uniform transverse electric field and Coriolis force using energy method and supplemented with Galerkin Technique. The sufficient condition for stability is obtained for sufficiently small values of the Reynolds number, R e . From this condition we show that strengthening or weakening of the stability criterion is dictated by the values of the strength of electric field, the coefficient of couple stress fluid and independent of Taylor number. In particular, it is shown that the interaction of electric field with couple stress is more effective in stabilizing the poorly conducting couple stress fluid compared to that in an ordinary Newtonian viscous fluid. (author)

Self-force as probe of internal structure

International Nuclear Information System (INIS)

Isoyama, Soichiro; Poisson, Eric

2012-01-01

The self-force acting on a (scalar or electric) charge held in place outside a massive body contains information about the body's composition, and can therefore be used as a probe of internal structure. We explore this theme by computing the (scalar or electromagnetic) self-force when the body is a spherical ball of perfect fluid in hydrostatic equilibrium, under the assumption that its rest-mass density and pressure are related by a polytropic equation of state. The body is strongly self-gravitating, and all computations are performed in exact general relativity. The dependence on internal structure is best revealed by expanding the self-force in powers of r -1 0 , with r 0 denoting the radial position of the charge outside the body. To the leading order, the self-force scales as r -3 0 and depends only on the square of the charge and the body's mass; the leading self-force is universal. The dependence on internal structure is seen at the next order, r -5 0 , through a structure factor that depends on the equation of state. We compute this structure factor for relativistic polytropes, and show that for a fixed mass, it increases linearly with the body's radius in the case of the scalar self-force, and quadratically with the body's radius in the case of the electromagnetic self-force. In both cases we find that for a fixed mass and radius, the self-force is smaller if the body is more centrally dense, and larger if the mass density is more uniformly distributed. (paper)

Active sensing associated with spatial learning reveals memory-based attention in an electric fish.

Science.gov (United States)

Jun, James J; Longtin, André; Maler, Leonard

2016-05-01

Active sensing behaviors reveal what an animal is attending to and how it changes with learning. Gymnotus sp, a gymnotiform weakly electric fish, generates an electric organ discharge (EOD) as discrete pulses to actively sense its surroundings. We monitored freely behaving gymnotid fish in a large dark "maze" and extracted their trajectories and EOD pulse pattern and rate while they learned to find food with electrically detectable landmarks as cues. After training, they more rapidly found food using shorter, more stereotyped trajectories and spent more time near the food location. We observed three forms of active sensing: sustained high EOD rates per unit distance (sampling density), transient large increases in EOD rate (E-scans) and stereotyped scanning movements (B-scans) were initially strong at landmarks and food, but, after learning, intensified only at the food location. During probe (no food) trials, after learning, the fish's search area and intense active sampling was still centered on the missing food location, but now also increased near landmarks. We hypothesize that active sensing is a behavioral manifestation of attention and essential for spatial learning; the fish use spatial memory of landmarks and path integration to reach the expected food location and confine their attention to this region. Copyright © 2016 the American Physiological Society.

Electric Charge as a Form of Imaginary Energy

Directory of Open Access Journals (Sweden)

Tianxi Zhang

2008-04-01

Full Text Available Electric charge is considered as a form of imaginary energy. With this consideration, the energy of an electrically charged particle is a complex number. The real part is proportional to the mass, while the imaginary part is proportional to the electric charge. The energy of an antiparticle is given by conjugating the energy of its corresponding particle. Newton's law of gravity and Coulomb's law of electric force are classically unified into a single expression of the interaction between the complex energies of two electrically charged particles. Interaction between real energies (or masses is the gravitational force. Interaction between imaginary energies (or electric charges is the electromagnetic force. Since radiation is also a form of real energy, there are another two types of interactions between real energies: the mass-radiation interaction and the radiation-radiation interaction. Calculating the work done by the mass-radiation interaction on a photon, we can derive the Einsteinian gravitational redshift. Calculating the work done by the radiation-radiation interaction on a photon, we can obtain a radiation redshift. This study suggests the electric charge as a form of imaginary energy, so that classically unifies the gravitational and electric forces and derives the Einsteinian gravitational redshift.

Effects of the visual-feedback-based force platform training with functional electric stimulation on the balance and prevention of falls in older adults: a randomized controlled trial.

Science.gov (United States)

Li, Zhen; Wang, Xiu-Xia; Liang, Yan-Yi; Chen, Shu-Yan; Sheng, Jing; Ma, Shao-Jun

2018-01-01

Force platform training with functional electric stimulation aimed at improving balance may be effective in fall prevention for older adults. Aim of the study is to evaluate the effects of the visual-feedback-based force platform balance training with functional electric stimulation on balance and fall prevention in older adults. A single-centre, unblinded, randomized controlled trial was conducted. One hundred and twenty older adults were randomly allocated to two groups: the control group ( n  = 60, one-leg standing balance exercise, 12 min/d) or the intervention group ( n  = 60, force platform training with functional electric stimulation, 12 min/d). The training was provided 15 days a month for 3 months by physical therapists. Medial-lateral and anterior-posterior maximal range of sway with eyes open and closed, the Berg Balance Scale, the Barthel Index, the Falls Efficacy scale-International were assessed at baseline and after the 3-month intervention. A fall diary was kept by each participant during the 6-month follow-up. On comparing the two groups, the intervention group showed significantly decreased ( p  Falls Efficacy Scale-International ( p  fall rates ( p  falls in older adults.

Simulating demand for electric vehicles using revealed preference data

International Nuclear Information System (INIS)

Driscoll, Áine; Lyons, Seán; Mariuzzo, Franco; Tol, Richard S.J.

2013-01-01

We have modelled the market for new cars in Ireland with the aim of quantifying the values placed on a range of observable car characteristics. Mid-sized petrol cars with a manual transmission sell best. Price and perhaps fuel cost are negatively associated with sales, and acceleration and perhaps range are positively associated. Hybrid cars are popular. The values of car characteristics are then used to simulate the likely market shares of three new electric vehicles. Electric vehicles tend to be more expensive even after tax breaks and subsidies are applied, but we assume their market shares would benefit from an “environmental” premium similar to those of hybrid cars. The “environmental” premium and the level of subsidies would need to be raised to incredible levels to reach the government target of 10% market penetration of all-electric vehicles. -- Highlights: •Market values placed on a range of observable car characteristics are quantified. •We simulate market shares of electrical vehicles from values of car characteristics. •We assume electric vehicles will benefit from an “environmental” premium. •Large premium not enough to reach government targets for market penetration. •Very high subsidies required to reach government targets for market penetration

Control of flow geometry using electromagnetic body forcing

International Nuclear Information System (INIS)

Rossi, L.; Bocquet, S.; Ferrari, S.; Garcia de la Cruz, J.M.; Lardeau, S.

2009-01-01

This paper presents conceptual experiments and simulations aiming at controlling flow geometries. Such flow design is performed by driving electromagnetically a shallow layer of brine, the forcing being generated by a transverse electrical current and different combinations of permanent magnets placed underneath the brine supporting wall. It is shown how different basic flow characteristics can be obtained with a single pair of magnets, by varying the angle with the electrical current. These basic flows are proposed as potential building blocks for advanced and complex flows studies. Three typical flow structures are presented to illustrate these building blocks. The discussion is then extended to multi-scale geometry by using blocks of various sizes. The flow is analysed using complementary experiments and numerical simulations. A good agreement is found between the 3D simulations and the experiments for both velocity and acceleration fields, which allows a higher degree of confidence in designing and modelling such flows. As the control of the flow geometry is important for mixing, in particular at low Reynolds number, we also illustrate the different stirring properties of the electromagnetically forced flows by comparing visualisations of passive scalars. They reveal complementary mixing properties for each of the building blocks.

Microscopic study of electrical properties of CrSi2 nanocrystals in silicon

Directory of Open Access Journals (Sweden)

Lányi Štefan

2011-01-01

Full Text Available Abstract Semiconducting CrSi2 nanocrystallites (NCs were grown by reactive deposition epitaxy of Cr onto n-type silicon and covered with a 50-nm epitaxial silicon cap. Two types of samples were investigated: in one of them, the NCs were localized near the deposition depth, and in the other they migrated near the surface. The electrical characteristics were investigated in Schottky junctions by current-voltage and capacitance-voltage measurements. Atomic force microscopy (AFM, conductive AFM and scanning probe capacitance microscopy (SCM were applied to reveal morphology and local electrical properties. The scanning probe methods yielded specific information, and tapping-mode AFM has shown up to 13-nm-high large-area protrusions not seen in the contact-mode AFM. The electrical interaction of the vibrating scanning tip results in virtual deformation of the surface. SCM has revealed NCs deep below the surface not seen by AFM. The electrically active probe yielded significantly better spatial resolution than AFM. The conductive AFM measurements have shown that the Cr-related point defects near the surface are responsible for the leakage of the macroscopic Schottky junctions, and also that NCs near the surface are sensitive to the mechanical and electrical stress induced by the scanning probe.

Force on an electric/magnetic dipole and classical approach to spin-orbit coupling in hydrogen-like atoms

Science.gov (United States)

Kholmetskii, A. L.; Missevitch, O. V.; Yarman, T.

2017-09-01

We carry out the classical analysis of spin-orbit coupling in hydrogen-like atoms, using the modern expressions for the force and energy of an electric/magnetic dipole in an electromagnetic field. We disclose a novel physical meaning of this effect and show that for a laboratory observer the energy of spin-orbit interaction is represented solely by the mechanical energy of the spinning electron (considered as a gyroscope) due to the Thomas precession of its spin. Concurrently we disclose some errors in the old and new publications on this subject.

Force law in material media, hidden momentum and quantum phases

International Nuclear Information System (INIS)

Kholmetskii, Alexander L.; Missevitch, Oleg V.; Yarman, T.

2016-01-01

We address to the force law in classical electrodynamics of material media, paying attention on the force term due to time variation of hidden momentum of magnetic dipoles. We highlight that the emergence of this force component is required by the general theorem, deriving zero total momentum for any static configuration of charges/currents. At the same time, we disclose the impossibility to add this force term covariantly to the Lorentz force law in material media. We further show that the adoption of the Einstein–Laub force law does not resolve the issue, because for a small electric/magnetic dipole, the density of Einstein–Laub force integrates exactly to the same equation, like the Lorentz force with the inclusion of hidden momentum contribution. Thus, none of the available expressions for the force on a moving dipole is compatible with the relativistic transformation of force, and we support this statement with a number of particular examples. In this respect, we suggest applying the Lagrangian approach to the derivation of the force law in a magnetized/polarized medium. In the framework of this approach we obtain the novel expression for the force on a small electric/magnetic dipole, with the novel expression for its generalized momentum. The latter expression implies two novel quantum effects with non-topological phases, when an electric dipole is moving in an electric field, and when a magnetic dipole is moving in a magnetic field. These phases, in general, are not related to dynamical effects, because they are not equal to zero, when the classical force on a dipole is vanishing. The implications of the obtained results are discussed.

The Bearingless Electrical Machine

Science.gov (United States)

Bichsel, J.

1992-01-01

Electromagnetic bearings allow the suspension of solids. For rotary applications, the most important physical effect is the force of a magnetic circuit to a high permeable armature, called the MAXWELL force. Contrary to the commonly used MAXWELL bearings, the bearingless electrical machine will take advantage of the reaction force of a conductor carrying a current in a magnetic field. This kind of force, called Lorentz force, generates the torque in direct current, asynchronous and synchronous machines. The magnetic field, which already exists in electrical machines and helps to build up the torque, can also be used for the suspension of the rotor. Besides the normal winding of the stator, a special winding was added, which generates forces for levitation. So a radial bearing, which is integrated directly in the active part of the machine, and the motor use the laminated core simultaneously. The winding was constructed for the levitating forces in a special way so that commercially available standard ac inverters for drives can be used. Besides wholly magnetic suspended machines, there is a wide range of applications for normal drives with ball bearings. Resonances of the rotor, especially critical speeds, can be damped actively.

Frequency-dependent transient response of an oscillating electrically actuated droplet

International Nuclear Information System (INIS)

Dash, S; Kumari, N; Garimella, S V

2012-01-01

The transient response of a millimeter-sized sessile droplet under electrical actuation is experimentally investigated. Under dc actuation, the droplet spreading rate increases as the applied voltage is increased due to the higher electrical forces induced. At sufficiently high dc voltages, competition between the electrical actuation force, droplet inertia, the retarding surface tension force and contact line friction leads to droplet oscillation. The timescale for the droplet to attain its maximum wetted diameter during step actuation is analyzed. Systematic experiments are conducted over a frequency range of 5–200 Hz and actuation voltages of 40–80 V rms to determine the dependence of droplet oscillation on these parameters. The response of the droplet to different actuation frequencies and voltages is determined in terms of its contact angle and contact radius variation. The frequency of the driving force (equal to twice the frequency of the applied electrical signal) determines the mode of oscillation of the droplet which, together with its resonance characteristics, governs whether the droplet contact angle and contact radius vary in phase or out of phase with each other. In addition to the primary frequency response at the electrical forcing frequency, the droplet oscillation exhibits sub-harmonic oscillation at half of the forcing frequency that is attributed to the parametric nature of the electrical force acting on the triple contact line of the droplet. (paper)

Effects of the visual-feedback-based force platform training with functional electric stimulation on the balance and prevention of falls in older adults: a randomized controlled trial

Directory of Open Access Journals (Sweden)

Zhen Li

2018-01-01

Full Text Available Background Force platform training with functional electric stimulation aimed at improving balance may be effective in fall prevention for older adults. Aim of the study is to evaluate the effects of the visual-feedback-based force platform balance training with functional electric stimulation on balance and fall prevention in older adults. Methods A single-centre, unblinded, randomized controlled trial was conducted. One hundred and twenty older adults were randomly allocated to two groups: the control group (n = 60, one-leg standing balance exercise, 12 min/d or the intervention group (n = 60, force platform training with functional electric stimulation, 12 min/d. The training was provided 15 days a month for 3 months by physical therapists. Medial–lateral and anterior–posterior maximal range of sway with eyes open and closed, the Berg Balance Scale, the Barthel Index, the Falls Efficacy scale-International were assessed at baseline and after the 3-month intervention. A fall diary was kept by each participant during the 6-month follow-up. Results On comparing the two groups, the intervention group showed significantly decreased (p < 0.01 medial–lateral and anterior–posterior maximal range of sway with eyes open and closed. There was significantly higher improvement in the Berg Balance Scale (p < 0.05, the Barthel Index (p < 0.05 and the Falls Efficacy Scale-International (p < 0.05, along with significantly lesser number of injurious fallers (p < 0.05, number of fallers (p < 0.05, and fall rates (p < 0.05 during the 6-month follow-up in the intervention group. Conclusion This study showed that the visual feedback-based force platform training with functional electric stimulation improved balance and prevented falls in older adults.

The asymmetrical structure of Golgi apparatus membranes revealed by in situ atomic force microscope.

Directory of Open Access Journals (Sweden)

Haijiao Xu

Full Text Available The Golgi apparatus has attracted intense attentions due to its fascinating morphology and vital role as the pivot of cellular secretory pathway since its discovery. However, its complex structure at the molecular level remains elusive due to limited approaches. In this study, the structure of Golgi apparatus, including the Golgi stack, cisternal structure, relevant tubules and vesicles, were directly visualized by high-resolution atomic force microscope. We imaged both sides of Golgi apparatus membranes and revealed that the outer leaflet of Golgi membranes is relatively smooth while the inner membrane leaflet is rough and covered by dense proteins. With the treatment of methyl-β-cyclodextrin and Triton X-100, we confirmed the existence of lipid rafts in Golgi apparatus membrane, which are mostly in the size of 20 nm -200 nm and appear irregular in shape. Our results may be of significance to reveal the structure-function relationship of the Golgi complex and pave the way for visualizing the endomembrane system in mammalian cells at the molecular level.

Electricity in France

International Nuclear Information System (INIS)

Audigier, Pierre

1999-12-01

Contains Executive Summary and Chapters on: Historical background; The Nationalisation Law of 1946 and the present electricity regulatory framework; Other regulations and policies having an impact on the French electricity system; Forces for and against Liberalisation; The legislative framework in preparation; Electricity costs and prices; The main industrial player. EdF; Key nuclear issues; EdF and the HV transmission network; The non-nationalised distributors; Other players on the generation side; Conclusions. (Author)

The future of electric two-wheelers and electric vehicles in China

International Nuclear Information System (INIS)

Weinert, Jonathan; Ogden, Joan; Sperling, Dan; Burke, Andrew

2008-01-01

The method of force field analysis is used to examine the future technological and market evolution of electric two-wheelers (E2W) in China. The authors identify key forces driving and resisting future E2W market growth, root causes behind these forces, and important insights about the likelihood of a wide shift to larger three- and four-wheel electric vehicles (EV). The authors conclude that the key forces driving E2W market growth are: improvements in E2W and battery technology due to product modularity and modular industry structure, strong local regulatory support in the form of gasoline-powered motorcycle bans and loose enforcement of E2W standards, and deteriorating bus public transit service. The largest forces resisting E2W market growth are strong demand for gasoline-powered motorcycles, bans on E2Ws due to safety concerns in urban areas, and growing support for public transit. The balance of these forces appears to favor E2W market growth. This growth will likely drive vehicle electrification through continued innovation in batteries and motors, the switch from lead-acid to Li-ion batteries in E2Ws, and the development of larger E2Ws and EVs. There are however strong forces resisting vehicle electrification, including battery cost, charging infrastructure, and inherent complications with large battery systems. (author)

Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

Science.gov (United States)

Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

2013-01-01

After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

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

Science.gov (United States)

Rusu-Anghel, S.; Ene, A.

2017-05-01

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

Development of a Wind Directly Forced Heat Pump and Its Efficiency Analysis

OpenAIRE

Jwo, Ching-Song; Chien, Zi-Jie; Chen, Yen-Lin; Chien, Chao-Chun

2013-01-01

The requirements of providing electric energy through the wind-forced generator to the heat pump for water cooling and hot water heating grow significantly by now. This study proposes a new technique to directly adopt the wind force to drive heat pump systems, which can effectively reduce the energy conversion losses during the processes of wind force energy converting to electric energy and electric energy converting to kinetic energy. The operation of heat pump system transfers between chil...

Meeting the challenges of the new energy industry: The driving forces facing electric power generators and the natural gas industry

International Nuclear Information System (INIS)

Anon.

1995-01-01

The proceedings of the IGT national conference on meeting the challenges of the New Energy Industry: The driving forces facing Electric Power Generators and the Natural Gas Industry are presented. The conference was held June 19-21, 1995 at the Ambassador West Hotel in Downtown Chicago, Illinois. A separate abstract and indexing for each of the 18 papers presented for inclusion in the Energy Science and Technology Database

Meeting the challenges of the new energy industry: The driving forces facing electric power generators and the natural gas industry

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The proceedings of the IGT national conference on meeting the challenges of the New Energy Industry: The driving forces facing Electric Power Generators and the Natural Gas Industry are presented. The conference was held June 19-21, 1995 at the Ambassador West Hotel in Downtown Chicago, Illinois. A separate abstract and indexing for each of the 18 papers presented for inclusion in the Energy Science and Technology Database.

Reforming British Columbia's electricity market: A way forward. Final report

International Nuclear Information System (INIS)

1998-01-01

This report begins with background on developments in electricity market structure and customer access, recent electricity market developments in British Columbia, factors driving change in that market, key elements of electricity market reform, and the work of the task force appointed to propose such reform. It then presents a consensus proposal for reform from the task force. The proposal has four major elements: Increasing customer access; transition toward a vertically de-integrated market structure; ensuring that social values associated with the existing electricity market are protected and enhanced; and environmental concerns (increasing energy efficiency and favoring the development of environmentally desirable electricity generation technologies). Finally, the proposals are evaluated against the task force terms of reference. Includes glossary

A picture dictionary of electric glossary

International Nuclear Information System (INIS)

1974-01-01

This book has a lot of explanations on electric glossary with picture, which include basic important glossaries like nuclear, current theory, measuring, electro genesis, power transmission, supply of electric power, a rotary machine, application of electromotive force, electronic engineering, automatic control, electronic calculator, T.V and communication, material of electricity, electrochemistry, traffic, electric work, lighting and electric heater, regulations and standard.

A picture dictionary of electric glossary

Energy Technology Data Exchange (ETDEWEB)

NONE

1974-01-15

This book has a lot of explanations on electric glossary with picture, which include basic important glossaries like nuclear, current theory, measuring, electro genesis, power transmission, supply of electric power, a rotary machine, application of electromotive force, electronic engineering, automatic control, electronic calculator, T.V and communication, material of electricity, electrochemistry, traffic, electric work, lighting and electric heater, regulations and standard.

49 CFR 236.105 - Electric lock.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Electric lock. 236.105 Section 236.105 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...: All Systems Inspections and Tests; All Systems § 236.105 Electric lock. Electric lock, except forced...

DEFINITION OF LOCOMOTIVE TRACTION FORCE WITH REGARD TO UNEVEN LOADING OF WHEEL-MOTOR BLOCK

Directory of Open Access Journals (Sweden)

B. Ye. Bodnar

2013-11-01

Full Text Available Purpose. The article describes the most common methods for determining the locomotive traction force. Solving the tasks of traction calculations involves determination of the forces influencing the train at every point of the way. When choosing a rational trajectory of the train motion and the development of operational regulations of train driving it is necessary to determine the actual value of the locomotive traction force. Considering various factors, power value of traction electric motor of locomotive may have significant differences. Advancement of the operational definition system of the locomotive traction force during the calculations by electrical parameters of traction electric motor with regard to uneven load of wheel-motor block is the purpose of the article. Methodology. The method of determining the traction force of locomotives and diesel locomotives with electric transmission, which is based on primary data acquisition of traction electric engines of direct current behavior, was proposed. Sensors and their integration into the electrical circuitry of the locomotive in order to get the data in digital form and for operational calculation of the each traction motor mode and the definition of locomotive traction force are presented. Findings. The experimental investigation of the system of locomotive traction force determination with the electric traction motor ED-105 was offered. A comparison of electrical and mechanical power of the electric motor was conducted. Originality. The system of locomotives power operational definition, which takes into account the variable electro-mechanical factors of wheel and motor blocks and increases the accuracy of the calculations, was proposed. Practical value. The system is a part of an onboard complex in definition of energy-efficient regimes for trains movement and provides the definition of accelerating and decelerating forces.

Nanoscale electrowetting effects observed by using friction force microscopy.

Science.gov (United States)

Revilla, Reynier; Guan, Li; Zhu, Xiao-Yang; Yang, Yan-Lian; Wang, Chen

2011-06-21

We report the study of electrowetting (EW) effects under strong electric field on poly(methyl methacrylate) (PMMA) surface by using friction force microscopy (FFM). The friction force dependence on the electric field at nanometer scale can be closely related to electrowetting process based on the fact that at this scale frictional behavior is highly affected by capillary phenomena. By measuring the frictional signal between a conductive atomic force microscopy (AFM) tip and the PMMA surface, the ideal EW region (Young-Lippmann equation) and the EW saturation were identified. The change in the interfacial contact between the tip and the PMMA surface with the electric field strength is closely associated with the transition from the ideal EW region to the EW saturation. In addition, a reduction of the friction coefficient was observed when increasing the applied electric field in the ideal EW region. © 2011 American Chemical Society

Ponderomotive force near cyclotron resonance

Energy Technology Data Exchange (ETDEWEB)

Kono, Mitsuo; Sanuki, Heiji

1987-01-01

The ponderomotive force, which is involved in the excitation of macroscopic behaviors of plasma caused by wave motion, plays an important role in various non-linear wave motion phenomena. In the present study, equations for the pondermotive force for plasma in a uniform magnetic field is derived using a renormalization theory which is based on the Vlasov equation. It is shown that the pondermotive force, which diverges at the cyclotron resonence point according to adiabatic approximation, can be expressed by a non-divergent equation by taking into account the instability of the cyclotron orbit due to high-order scattering caused by a wave. This is related with chaotic particle behaviors near cyclotron resonance, where the pondermotive force is small and the diffusion process prevails. It is assumed here that the amplitude of the high-frequency electric field is not large and that the broadening of cyclotron levels is smaller than the distance between the levels. A global chaos will be created if the amplitude of the electric field becomes greater to allow the broadening to exceed the distance between the levels. (Nogami, K.).

Research on Braking Stability of Electro-mechanical Hybrid Braking System in Electric Vehicles

OpenAIRE

Ji, Fenzhu; Tian, Mi

2010-01-01

For the electro-mechanical hybrid braking system, which is composed of electric brake and general friction brake, the models of electric braking force, total braking force and the utilization adhesion coefficient for front and rear axles were established based on the analysis of braking torque distribution. The variation relationship between electric braking force and friction braking force in different braking intensity was calculated and analyzed with the paralleled-hybridized braking contr...

Improving the Electrical Parameters of a Photovoltaic Panel by Means of an Induced or Forced Air Stream

Directory of Open Access Journals (Sweden)

R. Mazón-Hernández

2013-01-01

Full Text Available The main priority in photovoltaic (PV panels is the production of electricity. The transformation of solar energy into electricity depends on the operating temperature in such a way that the performance increases with the decreasing temperatures. In the existing literature, different cooling techniques can be found. The purpose of most of them is to use air or water as thermal energy carriers. This work is focused on the use of air as a working fluid whose movement is either induced by natural convection or forced by means of a fan. The aim of this study is to characterise the electrical behaviour of the solar panels in order to improve the design of photovoltaic installations placed in roof applications ensuring low operating temperatures which will correct and reverse the effects produced on efficiency by high temperature. To do this, a test installation has been constructed at the Universidad Politécnica de Cartagena in Spain. In this paper, the results of the tests carried out on two identical solar panels are included. One of them has been modified and mounted on different channels through which air flows. The different studies conducted show the effects of the air channel cross-section, the air velocity, and the panel temperature on the electrical parameters of the solar panels, such as the voltage, current, power, and performance. The results conclude that the air space between the photovoltaic panels and a steel roof must be high enough to allow the panel to be cooled and consequently to achieve higher efficiency.

NON-NEUTRALIZED ELECTRIC CURRENT PATTERNS IN SOLAR ACTIVE REGIONS: ORIGIN OF THE SHEAR-GENERATING LORENTZ FORCE

International Nuclear Information System (INIS)

Georgoulis, Manolis K.; Titov, Viacheslav S.; Mikić, Zoran

2012-01-01

Using solar vector magnetograms of the highest available spatial resolution and signal-to-noise ratio, we perform a detailed study of electric current patterns in two solar active regions (ARs): a flaring/eruptive and a flare-quiet one. We aim to determine whether ARs inject non-neutralized (net) electric currents in the solar atmosphere, responding to a debate initiated nearly two decades ago that remains inconclusive. We find that well-formed, intense magnetic polarity inversion lines (PILs) within ARs are the only photospheric magnetic structures that support significant net current. More intense PILs seem to imply stronger non-neutralized current patterns per polarity. This finding revises previous works that claim frequent injections of intense non-neutralized currents by most ARs appearing in the solar disk but also works that altogether rule out injection of non-neutralized currents. In agreement with previous studies, we also find that magnetically isolated ARs remain globally current-balanced. In addition, we confirm and quantify the preference of a given magnetic polarity to follow a given sense of electric currents, indicating a dominant sense of twist in ARs. This coherence effect is more pronounced in more compact ARs with stronger PILs and must be of sub-photospheric origin. Our results yield a natural explanation of the Lorentz force, invariably generating velocity and magnetic shear along strong PILs, thus setting a physical context for the observed pre-eruption evolution in solar ARs.

Experimental investigation of the effect of an electric field on heat transfers at boiling point for a high-resistivity water in forced convection

International Nuclear Information System (INIS)

Morin, Henri; Verdier, Jacques

1964-10-01

The enhancement of heat exchanges with boiling water in forced convection in an annular duct is studied when applying an electric field between the two walls of the duct. At the local boiling and at saturation temperature, for a water resistivity comprised between 0.5 and 1 M Ω cm, with fields on the cylindrical interior surface of the canal comprised between 4 and 8 kV/cm, significant enhancements of the exchanged heat fluxes are noticed, 2.5 to 10 time superior to exchanges without electric field. When heating, heat fluxes may be increased from two to three times [fr

Electric heating guidelines: power smart home; 2. ed.

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

Guidelines, for use by B. C. Hydro, were established for proper planning and design of an electric heating system for residential buildings. The guidebook is divided into five sections: (1) comfort and electric heating systems, (2) contractors` guide to heat loss calculation, (3) imperial heat loss factors, (4) metric heat loss factors, and (5) installation guidelines for electric heating systems. Individual topics discussed include heat loss and the human body, heating systems and comfort, heat loss design, air leakage, and soil conductivity factors. Design considerations and equipment standards were described for the following electric heating systems: electric resistance baseboard systems, forced flow unitary heaters, electric radiant cable in-floor systems, radiant ceiling systems, forced warm air heating systems, furnaces, and heat pumps. 68 tabs., 29 figs.

Cogging Force Issues of Permanent Magnet Linear Generator for Electric Vehicle

Directory of Open Access Journals (Sweden)

Izzeldin Idris Abdalla

2017-09-01

Full Text Available Alternatives to hydraulic drives that used on vehicles are necessary in order to reduce the Carbon dioxide (CO2 emission and oil consumption. Hence better performance and efficiency of the vehicles can be achieved by using free piston engine, in which the piston reciprocate linearly with a permanent magnet linear generator (PMLG without the need of a crankshaft. The PMLG has high performance, but suffering from the cogging force. The cogging force induces undesired vibration and acoustic noise and makes a ripple in the thrust force. Moreover, the cogging force deteriorates the control characteristics, particularly in terms of the position control and speed precisely. This paper proposes Somaloy to replace the laminated silicon steel sheets in order to reduce the cogging force in a PMLG. Through a finite-element analysis, it has been shown that, the stator core made of Somaloy minimizes the cogging force of the PMLG, moreover, giving larger flux-linkage and back-electromotive force (B-EMF, respectively.

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-05-16

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

Mechanical, Thermal, and Electrical Energy Storage in a Single Working Body: Electrification and Thermal Effects upon Pressure-Induced Water Intrusion-Extrusion in Nanoporous Solids.

Science.gov (United States)

Grosu, Yaroslav; Mierzwa, Michał; Eroshenko, Valentine A; Pawlus, Sebastian; Chorażewski, Mirosław; Nedelec, Jean-Marie; Grolier, Jean-Pierre E

2017-03-01

This paper presents the first experimental evidence of pronounced electrification effects upon reversible cycle of forced water intrusion-extrusion in nanoporous hydrophobic materials. Recorded generation of electricity combined with high-pressure calorimetric measurements improves the energy balance of {nanoporous solid + nonwetting liquid} systems by compensating mechanical and thermal energy hysteresis in the cycle. Revealed phenomena provide a novel way of "mechanical to electrical" and/or "thermal to electrical" energy transformation with unprecedented efficiency and additionally open a perspective to increase the efficiency of numerous energy applications based on such systems taking advantage of electricity generation during operational cycle.

Relativity of Electric Quantity

Directory of Open Access Journals (Sweden)

GAO Zhong-wen

2017-04-01

Full Text Available The demonstration foundation，which is used to demonstrate that observed values from the interaction force between two charges，which are not at the same point would be different in different reference frames，is that the transmission of the interaction between charges needs time. Firstly，this paper analyzes the foundation of hypothetical process that the electric field and the magnetic field are built by one charge，and then the electromagnetic field would be transferred to another charge in vacuo by the speed of light，and produces force. It points out that from the simultaneity of relativity，the force applied to charge would occur in different time in the different reference frames，the force would be neither in the same size nor in the opposite direction，and Newton’s Third Law is not valid longer, the deeper cause of these conclusions would be known. On this basis，this paper gives the basis that force would keep invariant in different reference frames，and according to this condition，with the situation of the charge that under the Coulombian force and electromagnetism，the relative form of expression and demonstration methods of electric quantity in different reference frames are given. On the basis of the hypothesis that force would keep invariant in different reference frames，with the similar derivation process，the mass relativity equation of Einstein would be obtained.

A study on fixing force generation mechanism of ER gel

International Nuclear Information System (INIS)

Tanaka, H; Kakinuma, Y; Aoyama, T; Anzai, H

2009-01-01

Electro-rheological Gel (ERG) is a new functional elastomer which changes its surface frictional and adhesive property according to the intensity of applied electrical field. This unique property is called ERG effect. The upper sliding electrode placed on the surface of ERG is fixed by the adhesive effect of ERG under electrical field. Variable fixing forces due to adhesion are generated by this effect. However, relationship between physical factors and generated fixing force has not yet been clarified. In this study, physical mechanism of fixing phenomenon is elucidated experimentally from the view point of frictional force and adhesive force. From the results, empirical equation of generated fixing force is originally derived to establish the theory of ERG effect.

A study on fixing force generation mechanism of ER gel

Energy Technology Data Exchange (ETDEWEB)

Tanaka, H; Kakinuma, Y; Aoyama, T [School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522 (Japan); Anzai, H [Fujikura kasei Co., Ltd., 2-6-15 Shibakouen, Minato-ku, Tokyo (Japan)], E-mail: h-tanaka@ina.sd.keio.ac.jp

2009-02-01

Electro-rheological Gel (ERG) is a new functional elastomer which changes its surface frictional and adhesive property according to the intensity of applied electrical field. This unique property is called ERG effect. The upper sliding electrode placed on the surface of ERG is fixed by the adhesive effect of ERG under electrical field. Variable fixing forces due to adhesion are generated by this effect. However, relationship between physical factors and generated fixing force has not yet been clarified. In this study, physical mechanism of fixing phenomenon is elucidated experimentally from the view point of frictional force and adhesive force. From the results, empirical equation of generated fixing force is originally derived to establish the theory of ERG effect.

Electric theory

International Nuclear Information System (INIS)

Gong, Ha Seong

2006-02-01

This book explains electric theory which is divided into four chapters. The first chapter includes electricity and material, electric field, capacitance, magnetic field and electromagnetic force, inductance. The second chapter mentions electronic circuit analysis, electric resistance,heating and power, chemical activity on current and battery with electrolysis. The third chapter deals with an alternating current circuit about the basics of an AC circuit, operating of resistance, inductance and capacitance, series circuit and parallel circuit of PLC, an alternating current circuit, Three-phase Alternating current, two terminal pair network and voltage and current of non-linearity circuit. The last explains transient phenomena of RC series circuit, RL series circuit, transient phenomena of an alternating current circuit and transient phenomena of RLC series circuit.

Force Per Active Area and Muscle Injury during Electrically Stimulated Contractions

OpenAIRE

BLACK, CHRISTOPHER D.; MCCULLY, KEVIN K.

2008-01-01

Multiple mechanical factors have been implicated in the initiation of exercise-induced muscle injury. Although high absolute force levels are associated with greater injury, the importance of high force per active area independent of absolute force remains to be determined, especially in humans.

Acoustic Imaging Frequency Dynamics of Ferroelectric Domains by Atomic Force Microscopy

International Nuclear Information System (INIS)

Kun-Yu, Zhao; Hua-Rong, Zeng; Hong-Zhang, Song; Sen-Xing, Hui; Guo-Rong, Li; Qing-Rui, Yin; Shimamura, Kiyoshi; Kannan, Chinna Venkadasamy; Villora, Encarnacion Antonia Garcia; Takekawa, Shunji; Kitamura, Kenji

2008-01-01

We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy It is found that ferroelectric domain could be firstly visualized at lower frequency down to 0.5 kHz by AFM-based acoustic microscopy The frequency-dependent acoustic signal revealed a strong acoustic response in the frequency range from 7kHz to 10kHz, and reached maximum at 8.1kHz. The acoustic contrast mechanism can be ascribed to the different elastic response of ferroelectric microstructures to local elastic stress fields, which is induced by the acoustic wave transmitting in the sample when the piezoelectric transducer is vibrating and exciting acoustic wave under ac electric fields due to normal piezoelectric effects. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Manipulation of red blood cells with electric field

Science.gov (United States)

Saboonchi, Hossain; Esmaeeli, Asghar

2009-11-01

Manipulation of bioparticles and macromolecules is the central task in many biological and biotechnological processes. The current methods for physical manipulation takes advantage of different forces such as acoustic, centrifugal, magnetic, electromagnetic, and electric forces, as well as using optical tweezers or filtration. Among all these methods, however, the electrical forces are particularly attractive because of their favorable scale up with the system size which makes them well-suited for miniaturization. Currently the electric field is used for transportation, poration, fusion, rotation, and separation of biological cells. The aim of the current research is to gain fundamental understanding of the effect of electric field on the human red blood cells (RBCs) using direct numerical simulation. A front tracking/finite difference technique is used to solve the fluid flow and electric field equations, where the fluid in the cell and the blood (plasma) is modeled as Newtonian and incompressible, and the interface separating the two is treated as an elastic membrane. The behavior of RBCs is investigated as a function of the controlling parameters of the problem such as the strength of the electric field.

Model-based traction force microscopy reveals differential tension in cellular actin bundles.

Science.gov (United States)

Soiné, Jérôme R D; Brand, Christoph A; Stricker, Jonathan; Oakes, Patrick W; Gardel, Margaret L; Schwarz, Ulrich S

2015-03-01

Adherent cells use forces at the cell-substrate interface to sense and respond to the physical properties of their environment. These cell forces can be measured with traction force microscopy which inverts the equations of elasticity theory to calculate them from the deformations of soft polymer substrates. We introduce a new type of traction force microscopy that in contrast to traditional methods uses additional image data for cytoskeleton and adhesion structures and a biophysical model to improve the robustness of the inverse procedure and abolishes the need for regularization. We use this method to demonstrate that ventral stress fibers of U2OS-cells are typically under higher mechanical tension than dorsal stress fibers or transverse arcs.

Electricity and gas conference - a customer's perspective

International Nuclear Information System (INIS)

Timmons, P.S.

1997-01-01

Sterling Pulp Chemicals (SPC) is one of only a few companies in the world supplying both technology and chemicals for pulp bleaching. The company's electricity consumption represents more than 60 per cent of operating costs. The company regards energy as a commodity and considers electricity and gas as interchangeable energy sources. The deregulation of electrical markets in North America is following the trend set in the gas industry. SPC, as all other companies, is interested in having both gas and electricity delivered at lower costs. Options available to industrial consumers such as self-generation, purchase of either electricity or gas, use of financial instruments, etc., were explored. It was suggested that as a nation we must move quickly towards lower energy costs, with definite goals and timetables, to avoid having changes forced upon us by by external forces

Electromechanical Characterization of Single GaN Nanobelt Probed with Conductive Atomic Force Microscope

Science.gov (United States)

Yan, X. Y.; Peng, J. F.; Yan, S. A.; Zheng, X. J.

2018-04-01

The electromechanical characterization of the field effect transistor based on a single GaN nanobelt was performed under different loading forces by using a conductive atomic force microscope (C-AFM), and the effective Schottky barrier height (SBH) and ideality factor are simulated by the thermionic emission model. From 2-D current image, the high value of the current always appears on the nanobelt edge with the increase of the loading force less than 15 nN. The localized (I-V) characteristic reveals a typical rectifying property, and the current significantly increases with the loading force at the range of 10-190 nN. The ideality factor is simulated as 9.8 within the scope of GaN nano-Schottky diode unity (6.5-18), therefore the thermionic emission current is dominant in the electrical transport of the GaN-tip Schottky junction. The SBH is changed through the piezoelectric effect induced by the loading force, and it is attributed to the enhanced current. Furthermore, a single GaN nanobelt has a high mechanical-induced current ratio that could be made use of in a nanoelectromechanical switch.

Influence of Oxygen Pressure on the Domain Dynamics and Local Electrical Properties of BiFe0.95Mn0.05O3 Thin Films Studied by Piezoresponse Force Microscopy and Conductive Atomic Force Microscopy

Directory of Open Access Journals (Sweden)

Kunyu Zhao

2017-11-01

Full Text Available In this work, we have studied the microstructures, nanodomains, polarization preservation behaviors, and electrical properties of BiFe0.95Mn0.05O3 (BFMO multiferroic thin films, which have been epitaxially created on the substrates of SrRuO3, SrTiO3, and TiN-buffered (001-oriented Si at different oxygen pressures via piezoresponse force microscopy and conductive atomic force microscopy. We found that the pure phase state, inhomogeneous piezoresponse force microscopy (PFM response, low leakage current with unidirectional diode-like properties, and orientation-dependent polarization reversal properties were found in BFMO thin films deposited at low oxygen pressure. Meanwhile, these films under high oxygen pressures resulted in impurities in the secondary phase in BFMO films, which caused a greater leakage that hindered the polarization preservation capability. Thus, this shows the important impact of the oxygen pressure on modulating the physical effects of BFMO films.

Electrical characterization of InAs/GaAs (110) nanostructures by conductive atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Beinik, Igor; Teichert, Christian [Institute of Physics, Montanuniversitaet Leoben (Austria); Diez-Merino, Laura; Tejedor, Paloma [Instituto de Ciencia de Materiales de Madrid (Spain). CSIC

2009-07-01

Self-assembled InAs quantum dots and wires have been studied over many years and still they are of great interest for application in nanoelectronics, high-speed spintronic devices, etc. Samples for our investigation were grown by molecular beam epitaxy on misoriented (110) GaAs substrates. Conductive Atomic Force Microscopy (C-AFM) technique was used to study the surface topography and conductivity simultaneously. Comparison of the corresponding cross-section profiles indicated that InAs nucleation takes place on the[1-10]-oriented step bunches, forming 3 nm-high and up to 70 nm-wide wires of variable length. On the other hand,[1-12]-type steps very rarely appeared to be decorated by InAs, also in agreement with previous TEM studies. The presented results prove that C-AFM technique might be successfully applied as a tool for investigation of electrical properties in III-V quantum dots and wires on the nanometer scale.

May the Forces Be with You!

Science.gov (United States)

Sirola, Christopher

2018-01-01

In everyday life, we usually directly note two basic forces: gravity and electromagnetism. Gravity--as in the acceleration due to Earth's gravity--tends to be a background force of sorts, something that is always present and always the same. We don't always see electricity and/or magnetism as such, but their subsidiaries are all around…

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

Electric air filtration movie

International Nuclear Information System (INIS)

Bergman, W.; Jaeger, R.

1984-01-01

The use of electrostatics to improve the performance of conventional air filters has gained considerable attention in recent years. This interest is due to the higher efficiency and reduced pressure drop of electrically enhanced filters compared to conventional fibrous filters. This 30-minute movie presents a state of the art review of electric air filters in the United States with major illustrations provided by the research and development program at the Lawrence Livermore National Laboratory sponsored by the Department of Energy. The electric air filters described in this movie are mechanical air filters to which electrical forces have been added

Correlations of filtration flux enhanced by electric fields in crossflow microfiltration

Energy Technology Data Exchange (ETDEWEB)

Okada, K.; Nagase, Y. [Kurashiki University of Science and the Arts, Okayama (Japan). Department of Chemical Technology; Ohnishi, Y.; Nishihan, A.; Akagi, Y. [Okayama University of Science, Okayama (Japan). Department of Applied Chemistry

1997-12-01

The steady state filtration flux in electrically-enhanced crossflow microfiltration is estimated using a correlation equation proposed for several kinds of suspensions. Baker`s yeast and Rhodotorula glutinis were used as model samples of microbial cells, and PMMA particles were used as samples of non-living solids. Application of the electric field in crossflow microfiltration is a useful method for improving the filtration flux of these samples. High flux levels for the cells were achieved when an electric field above 3000 V/m was applied. The effect of the electric field in increasing the filtration flux of the steady state was analyzed theoretically using a force balance model where the viscous drag force, F{sub J}, the electrophoretic force, F{sub E}, and the re-entraining force, F{sub B}, were considered to act on a particle on the membrane surface under a steady state of filtration, respectively. From force balance analysis, it is found that on application of an electric field, the electro-osmotic effect can be neglected in the present study, so that the filtration flux of the steady state, J{sub ES}, can be presented by, J{sub ES}=U{sub EP}E+J{sub OS} where U{sub EP} is the electrophoretic mobility of particles and E is the electric field applied. J{sub OS} is the filtration flux in the absence of an electric field, which is correlated with the operating parameters for suspensions tested. 22 refs., 7 figs., 1 tab.

Effect of tendon vibration during wide-pulse neuromuscular electrical stimulation (NMES) on the decline and recovery of muscle force.

Science.gov (United States)

Bochkezanian, Vanesa; Newton, Robert U; Trajano, Gabriel S; Vieira, Amilton; Pulverenti, Timothy S; Blazevich, Anthony J

2017-05-02

Neuromuscular electrical stimulation (NMES) is commonly used to activate skeletal muscles and reverse muscle atrophy in clinical populations. Clinical recommendations for NMES suggest the use of short pulse widths (100-200 μs) and low-to-moderate pulse frequencies (30-50 Hz). However, this type of NMES causes rapid muscle fatigue due to the (non-physiological) high stimulation intensities and non-orderly recruitment of motor units. The use of both wide pulse widths (1000 μs) and tendon vibration might optimize motor unit activation through spinal reflex pathways and thus delay the onset of muscle fatigue, increasing muscle force and mass. Thus, the objective of this study was to examine the acute effects of patellar tendon vibration superimposed onto wide-pulse width (1000 μs) knee extensor electrical stimulation (NMES, 30 Hz) on peak muscle force, total impulse before "muscle fatigue", and the post-exercise recovery of muscle function. Tendon vibration (Vib), NMES (STIM) or NMES superimposed onto vibration (STIM + Vib) were applied in separate sessions to 16 healthy adults. Total torque-time integral (TTI), maximal voluntary contraction torque (MVIC) and indirect measures of muscle damage were tested before, immediately after, 1 h and 48 h after each stimulus. TTI increased (145.0 ± 127.7%) in STIM only for "positive responders" to the tendon vibration (8/16 subjects), but decreased in "negative responders" (-43.5 ± 25.7%). MVIC (-8.7%) and rectus femoris electromyography (RF EMG) (-16.7%) decreased after STIM (group effect) for at least 1 h, but not after STIM + Vib. No changes were detected in indirect markers of muscle damage in any condition. Tendon vibration superimposed onto wide-pulse width NMES increased TTI only in 8 of 16 subjects, but reduced voluntary force loss (fatigue) ubiquitously. Negative responders to tendon vibration may derive greater benefit from wide-pulse width NMES alone.

Sustained orderly development of the solar electric technologies

International Nuclear Information System (INIS)

Aitken, D.W.

1992-01-01

This article examines the need of electric utilities to support the commercialization of solar electric technologies now in order to have the technology available for future energy resources. The topics of the article include deteriorating opportunities, sustained orderly development of solar electric technologies, historical aspects, and market forces in the solar electric industry

Optimal Charging of Electric Vehicles with Trading on the Intraday Electricity Market

Directory of Open Access Journals (Sweden)

Ilham Naharudinsyah

2018-06-01

Full Text Available Trading on the energy market is a possible way to reduce the electricity costs of charging electric vehicles at public charging stations. In many European countries, it is possible to trade electricity until shortly before the period of delivery on so called intraday electricity markets. In the present work, the potential for reducing the electricity costs by trading on the intraday market is investigated using the example of the German market. Based on simulations, the authors reveal that by optimizing the charging schedule together with the trading on the intraday electricity market, the costs can be reduced by around 8% compared to purchasing all the required energy from the energy supplier. By allowing the charging station operator to resell the energy to the intraday electricity market, an additional cost reduction of around 1% can be achieved. Besides the potential cost savings, the impacts of the trading unit and of the lead time of the intraday electricity market on the costs are investigated. The authors reveal that the achievable electricity costs can be strongly affected by the lead time, while the trading unit has only a minor effect on the costs.

Effect of low temperature oxygen plasma treatment on microstructure and adhesion force of graphene

Science.gov (United States)

Zhu, Jun; Deng, Heijun; Xue, Wei; Wang, Quan

2018-01-01

Graphene has attracted strong attention due to its unique mechanical, electrical, thermal and magnetic properties. In this work, we investigate the effect of low temperature oxygen plasma treatment on microstructure and adhesion force of single-layer graphene (SLG). Low temperature oxygen plasma is used to treat SLG grown by chemical vapor deposition through varying the exposure time. Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy are utilized to identify changes before and after treatment. Raman spectra of treated graphene reveal that peak intensity of the characteristic D and D' peaks increase. Meanwhile, degradation of the G and 2D peaks in X-ray photoelectron spectroscopy indicates that abundant Csbnd OH and Cdbnd O functional groups are introduced into graphene after treatment. AFM investigation shows that surface roughness and adhesion force of treated graphene increase significantly firstly and then slowly. Therefore, this work would offer a practical route to improve the performance of graphene-based devices.

Coulomb torque - a general theory for electrostatic forces in many-body systems

International Nuclear Information System (INIS)

Khachatourian, Armik V M; Wistrom, Anders O

2003-01-01

In static experiments that comprise three conducting spheres suspended by torsion wires and held at constant electric potential, a net angular displacement about their centres has been observed. We demonstrate that the observed rotation is consistent with Coulomb's law of electrical forces complemented by Gauss' surface integrals for electrical potential. Analysis demonstrates that electrostatic torque is the result of electrostatic forces acting on an asymmetric distribution of charges residing on the surfaces of the spheres. The asymptotic value for electrostatic torque is proportional to the inverse of the fourth power of separation distance with the rotation direction, up or down taken perpendicular to a plane passing through sphere centres, given explicitly by the equation for torque. The identification of electrostatic torque prompts further analysis of models of matter at all size scales where electrostatic forces are the dominant operative force

Coulomb torque - a general theory for electrostatic forces in many-body systems

CERN Document Server

Khachaturian, A V M

2003-01-01

In static experiments that comprise three conducting spheres suspended by torsion wires and held at constant electric potential, a net angular displacement about their centres has been observed. We demonstrate that the observed rotation is consistent with Coulomb's law of electrical forces complemented by Gauss' surface integrals for electrical potential. Analysis demonstrates that electrostatic torque is the result of electrostatic forces acting on an asymmetric distribution of charges residing on the surfaces of the spheres. The asymptotic value for electrostatic torque is proportional to the inverse of the fourth power of separation distance with the rotation direction, up or down taken perpendicular to a plane passing through sphere centres, given explicitly by the equation for torque. The identification of electrostatic torque prompts further analysis of models of matter at all size scales where electrostatic forces are the dominant operative force.

Exact expressions for colloidal plane-particle interaction forces and energies with applications to atomic force microscopy

International Nuclear Information System (INIS)

Zypman, F R

2006-01-01

We begin by deriving a general useful theoretical relationship between the plane-particle interaction forces in solution, and the corresponding plane-plane interaction energies. This is the main result of the paper. It provides a simple tool to obtain closed-form particle-plane forces from knowledge of plane-plane interaction energies. To illustrate the simplicity of use of this general formalism, we apply it to find particle-plane interactions within the Derjaguin-Landau-Verwey-Overbeek (DLVO) framework. Specifically, we obtain analytical expressions for forces and interaction energies in the van der Waals and the electrical double layer cases. The van der Waals expression is calculated here for benchmarking purposes and is compared with well-established expressions from Hamaker theory. The interactions for the electric double layer situation are computed in two cases: the linear superposition approximation and the constant surface potential. In both cases, our closed-form expressions were compared with existent numerical results. We also use the main result of this paper to generate an analytical force-separation expression based on atomic force microscope experiments for a tip and surface immersed in an aqueous solution, and compare it with the corresponding numerical results. Finally, based on our main result, we generalize the Derjaguin approximation by calculating the next order of approximation, thus obtaining a formula valuable for colloidal interaction estimations

Touching force response of the piezoelectric Braille cell.

Science.gov (United States)

Smithmaitrie, Pruittikorn; Kanjantoe, Jinda; Tandayya, Pichaya

2008-11-01

The objective of this research is to investigate dynamic responses of the piezoelectric Braille cell when it is subjected to both electrical signal and touching force. Physical behavior of the piezoelectric actuator inside the piezoelectric Braille cell is analyzed. The mathematical model of the piezoelectric Braille system is presented. Then, data of visually impaired people using a Braille Note is studied as design information and a reference input for calculation of the piezoelectric Braille response under the touching force. The results show dynamic responses of the piezoelectric Braille cell. The designed piezoelectric bimorph has a settling time of 0.15 second. The relationship between the Braille dot height and applied voltage is linear. The behavior of the piezoelectric Braille dot when it is touched during operation shows that the dot height is decreased as the force increases. The result provides understanding of the piezoelectric Braille cell behavior under both touching force and electrical excitation simultaneously. This is the important issue for the design and development of piezoelectric Braille cells in senses of controlling Braille dot displacement or force-feedback in the future.

Electric versus hydraulic hospital beds: differences in use during basic nursing tasks.

Science.gov (United States)

Capodaglio, Edda Maria

2013-01-01

Biomechanical, postural and ergonomic aspects during real patient-assisting tasks performed by nurses using an electric versus a hydraulic hospital bed were observed. While there were no differences in the flexed postures the nurses adopted, longer performance times were recorded when electric beds were used. Subjective effort, force exertion and lumbar shear forces exceeding safety limits proved electric beds were superior. Patients' dependency level seemed to influence the type of nurses' intervention (duration and force actions), irrespective of the bed used. The nurses greatly appreciated the electric bed. Its use seemed to reduce the level of effort perceived during care giving and the postural load during critical subtasks. Ergonomics and organizational problems related to adopting electric beds in hospital wards should be addressed further to make their use more efficient.

Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels.

Science.gov (United States)

Jeggle, Pia; Smith, Ewan St J; Stewart, Andrew P; Haerteis, Silke; Korbmacher, Christoph; Edwardson, J Michael

2015-08-14

ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers. Copyright © 2015 Elsevier Inc. All rights reserved.

[Electrical acupoint stimulation increases athletes' rapid strength].

Science.gov (United States)

Yang, Hua-yuan; Liu, Tang-yi; Kuai, Le; Gao, Ming

2006-05-01

To search for a stimulation method for increasing athletes' performance. One hundred and fifty athletes were randomly divided into a trial group and a control group, 75 athletes in each group. Acupoints were stimulated with audio frequency pulse modulated wave and multi-blind method were used to investigate effects of the electric stimulation of acupoints on 30-meter running, standing long jumping and Cybex isokinetic testing index. The acupoint electric stimulation method could significantly increase athlete's performance (P < 0.05), and the biomechanical indexes, maximal peak moment of force (P < 0.05), force moment accelerating energy (P < 0.05) and average power (P < 0.05). Electrical acupoint stimulation can enhance athlete's rapid strength.

Improving Energy Security for Air Force Installations

Science.gov (United States)

Schill, David

Like civilian infrastructure, Air Force installations are dependent on electrical energy for daily operations. Energy shortages translate to decreased productivity, higher costs, and increased health risks. But for the United States military, energy shortages have the potential to become national security risks. Over ninety-five percent of the electrical energy used by the Air Force is supplied by the domestic grid, which is susceptible to shortages and disruptions. Many Air Force operations require a continuous source of energy, and while the Air Force has historically established redundant supplies of electrical energy, these back-ups are designed for short-term outages and may not provide sufficient supply for a longer, sustained power outage. Furthermore, it is the goal of the Department of Defense to produce or procure 25 percent of its facility energy from renewable sources by fiscal year 2025. In a government budget environment where decision makers are required to provide more capability with less money, it is becoming increasingly important for informed decisions regarding which energy supply options bear the most benefit for an installation. The analysis begins by exploring the field of energy supply options available to an Air Force installation. The supply options are assessed according to their ability to provide continuous and reliable energy, their applicability to unique requirements of Air Force installations, and their costs. Various methods of calculating energy usage by an installation are also addressed. The next step of this research develops a methodology and tool which assesses how an installation responds to various power outage scenarios. Lastly, various energy supply options are applied to the tool, and the results are reported in terms of cost and loss of installation capability. This approach will allow installation commanders and energy managers the ability to evaluate the cost and effectiveness of various energy investment options.

Electric-car simulation

Science.gov (United States)

Chapman, C. P.; Slusser, R. A.

1980-01-01

PARAMET, interactive simulation program for parametric studies of electric vehicles, guides user through simulation by menu and series of prompts for input parameters. Program considers aerodynamic drag, rolling resistance, linear and rotational acceleration, and road gradient as forces acting on vehicle.

Feather retention force in broilers ante-, peri-, and post-mortem as influenced by electrical and carbon dioxide stunning.

Science.gov (United States)

Buhr, R J; Cason, J A; Rowland, G N

1997-11-01

Stunning and slaughter trials were conducted to evaluate the influence of stunning method (electrical 50 V alternating current, CO2 gas: 0 to 40% for 90 s or 40 to 60% for 30 s) on feather retention force (FRF) in commercial broilers. Feathers from the pectoral, sternal, and femoral feather tracts were sampled with a force gauge before stunning (ante-mortem) and contralaterally either after stunning (peri-mortem from 0.5 to 4 min) or after stunning and bleeding (post-mortem from 2 to 6 min). Prior to stunning, ante-mortem FRF values varied among assigned stunning methods only for the pectoral (7%) feather tract. After stunning, peri-mortem FRF values were higher only for the sternal tract (11% for 40 to 60% CO2 for 30 s); whereas after stunning and bleeding, post-mortem FRF values were lower than ante- or peri-mortem only for the sternal tract (10% lower for 40 to 60% CO2 for 30 s). Peri- and post-mortem FRF values did not differ among stunning methods for the pectoral and femoral feather tracts. Small changes in FRF values occurred from ante-mortem to peri-mortem (-1 to +12%), and from ante-mortem to post-mortem (-2 to +8%) across stunning methods. A significant increase was determined for only the pectoral tract (7%) from ante- to peri-mortem across stunning methods. Electrically stunned broilers that were not bled gained weight in excess of the 36 feathers removed (0.16%), apparently due to body surface water pickup during the brine-stunning process, whereas CO2-stunned broilers lost weight due to excretion of cloacal contents (-0.31 to -0.98%). The change in body weight among stunning methods was significant (P defeathering efficiency may not differ after scalding.

The USAF Electric Propulsion Program

National Research Council Canada - National Science Library

Spores, Ronald

1999-01-01

...: Propulsion Directorate and Air Force Office of Scientific Research (AFOSR). The Propulsion Directorate conducts electric propulsion efforts in basic research, engineering development, and space experiments...

Solar thermal energy conversion to electrical power

International Nuclear Information System (INIS)

Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.

2014-01-01

The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data

Design and implementation of a novel modal space active force control concept for spatial multi-DOF parallel robotic manipulators actuated by electrical actuators.

Science.gov (United States)

Yang, Chifu; Zhao, Jinsong; Li, Liyi; Agrawal, Sunil K

2018-01-01

Robotic spine brace based on parallel-actuated robotic system is a new device for treatment and sensing of scoliosis, however, the strong dynamic coupling and anisotropy problem of parallel manipulators result in accuracy loss of rehabilitation force control, including big error in direction and value of force. A novel active force control strategy named modal space force control is proposed to solve these problems. Considering the electrical driven system and contact environment, the mathematical model of spatial parallel manipulator is built. The strong dynamic coupling problem in force field is described via experiments as well as the anisotropy problem of work space of parallel manipulators. The effects of dynamic coupling on control design and performances are discussed, and the influences of anisotropy on accuracy are also addressed. With mass/inertia matrix and stiffness matrix of parallel manipulators, a modal matrix can be calculated by using eigenvalue decomposition. Making use of the orthogonality of modal matrix with mass matrix of parallel manipulators, the strong coupled dynamic equations expressed in work space or joint space of parallel manipulator may be transformed into decoupled equations formulated in modal space. According to this property, each force control channel is independent of others in the modal space, thus we proposed modal space force control concept which means the force controller is designed in modal space. A modal space active force control is designed and implemented with only a simple PID controller employed as exampled control method to show the differences, uniqueness, and benefits of modal space force control. Simulation and experimental results show that the proposed modal space force control concept can effectively overcome the effects of the strong dynamic coupling and anisotropy problem in the physical space, and modal space force control is thus a very useful control framework, which is better than the current joint

Cantilever contribution to the total electrostatic force measured with the atomic force microscope

International Nuclear Information System (INIS)

Guriyanova, Svetlana; Golovko, Dmytro S; Bonaccurso, Elmar

2010-01-01

The atomic force microscope (AFM) is a powerful tool for surface imaging at the nanometer scale and surface force measurements in the piconewton range. Among long-range surface forces, the electrostatic forces play a predominant role. They originate if the electric potentials of the substrate and of the tip of the AFM cantilever are different. A quantitative interpretation of the AFM signal is often difficult because it depends in a complicated fashion on the cantilever–tip–surface geometry. Since the electrostatic interaction is a long-range interaction, the cantilever, which is many microns from the surface, contributes to the total electrostatic force along with the tip. Here we present results of the electrostatic interaction between a conducting flat surface and horizontal or tilted cantilevers, with and without tips, at various distances from the surface. As addressed in a previous work, we show that the contribution of the cantilever to the overall force cannot be neglected. Based on a predictive model and on 3D confocal measurements, we discuss the influence of the tilting angle of the cantilever

Wire electric-discharge machining and other fabrication techniques

Science.gov (United States)

Morgan, W. H.

1983-01-01

Wire electric discharge machining and extrude honing were used to fabricate a two dimensional wing for cryogenic wind tunnel testing. Electric-discharge cutting is done with a moving wire electrode. The cut track is controlled by means of a punched-tape program and the cutting feed is regulated according to the progress of the work. Electric-discharge machining involves no contact with the work piece, and no mechanical force is exerted. Extrude hone is a process for honing finish-machined surfaces by the extrusion of an abrasive material (silly putty), which is forced through a restrictive fixture. The fabrication steps are described and production times are given.

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

Science.gov (United States)

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

2017-11-15

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

Effect of electron correlation on the forced electric dipole transition probabilities in fsup(N) systems

International Nuclear Information System (INIS)

Jankowski, K.; Smentek-Mielczarek, L.

1981-01-01

Results of model studies of the impact of electron correlation on the forced electric dipole transition probabilities between states of the 4fsup(N) configuration are reported for the [ 3 P] 0 - [ 3 F] 4 , [ 3 H] 4 transitions in Pr 3+ : LaCl 3 and for [ 7 F] 0 - [ 5 D] 2 , [ 7 F] 1 - [ 5 D] 1 hypersensitive transitions in Eu 3+ : LaCl 3 . For the former system the correlation effects cause a modification of earlier results by 40-95 per cent, whereas for the latter the probability changes by as much as two orders of magnitude. The great changes found in the case of hypersensitive transitions suggest that electron correlation effects may belong to the most important factors determining the nature of these transitions. Several types of effective correlation operators are considered and their relative importance is discussed. The results indicate that intermediate configurations including g orbitals are very important for the description of correlation effects. (author)

Biomechanical Evaluation of an Electric Power-Assisted Bicycle by a Musculoskeletal Model

Science.gov (United States)

Takehara, Shoichiro; Murakami, Musashi; Hase, Kazunori

In this study, we construct an evaluation system for the muscular activity of the lower limbs when a human pedals an electric power-assisted bicycle. The evaluation system is composed of an electric power-assisted bicycle, a numerical simulator and a motion capture system. The electric power-assisted bicycle in this study has a pedal with an attached force sensor. The numerical simulator for pedaling motion is a musculoskeletal model of a human. The motion capture system measures the joint angles of the lower limb. We examine the influence of the electric power-assisted force on each muscle of the human trunk and legs. First, an experiment of pedaling motion is performed. Then, the musculoskeletal model is calculated by using the experimental data. We discuss the influence on each muscle by electric power-assist. It is found that the muscular activity is decreased by the electric power-assist bicycle, and the reduction of the muscular force required for pedaling motion was quantitatively shown for every muscle.

Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Legrand, Bernard, E-mail: bernard.legrand@laas.fr [LAAS-CNRS, Université de Toulouse, CNRS, 7 avenue du colonel Roche, F-31400 Toulouse (France); Salvetat, Jean-Paul [CRPP, 115 avenue Schweitzer, F-33600 Pessac (France); Walter, Benjamin; Faucher, Marc; Théron, Didier [IEMN, avenue Henri Poincaré, F-59652 Villeneuve d’Ascq (France); Aimé, Jean-Pierre [CBMN, allée Geoffroy Saint Hilaire, Bât. B14, F-33600 Pessac (France)

2017-04-15

Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resotnance frequency above 10 MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5 fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100 pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10 nm). - Highlights: • Silicon MEMS resonators are used as AFM probes above 10 MHz. • Integrated capacitive transducers drive and sense sub-nanometer tip oscillation. • Force resolution is below 1 pN/√Hz. • Block copolymer surface is imaged using AM and FM AFM modes. • Probes are operated at small vibration amplitude in permanent viscoelastic contact.

Multi-MHz micro-electro-mechanical sensors for atomic force microscopy

International Nuclear Information System (INIS)

Legrand, Bernard; Salvetat, Jean-Paul; Walter, Benjamin; Faucher, Marc; Théron, Didier; Aimé, Jean-Pierre

2017-01-01

Silicon ring-shaped micro-electro-mechanical resonators have been fabricated and used as probes for dynamic atomic force microscopy (AFM) experiments. They offer resotnance frequency above 10 MHz, which is notably greater than that of usual cantilevers and quartz-based AFM probes. On-chip electrical actuation and readout of the tip oscillation are obtained by means of built-in capacitive transducers. Displacement and force resolutions have been determined from noise analysis at 1.5 fm/√Hz and 0.4 pN/√Hz, respectively. Despite the high effective stiffness of the probes, the tip-surface interaction force is kept below 1 nN by using vibration amplitude significantly below 100 pm and setpoint close to the free vibration conditions. Imaging capabilities in amplitude- and frequency-modulation AFM modes have been demonstrated on block copolymer surfaces. Z-spectroscopy experiments revealed that the tip is vibrating in permanent contact with the viscoelastic material, with a pinned contact line. Results are compared to those obtained with commercial AFM cantilevers driven at large amplitudes (>10 nm). - Highlights: • Silicon MEMS resonators are used as AFM probes above 10 MHz. • Integrated capacitive transducers drive and sense sub-nanometer tip oscillation. • Force resolution is below 1 pN/√Hz. • Block copolymer surface is imaged using AM and FM AFM modes. • Probes are operated at small vibration amplitude in permanent viscoelastic contact.

Hall devices improve electric motor efficiency

Science.gov (United States)

Haeussermann, W.

1979-01-01

Efficiency of electric motors and generators is reduced by radial magnetic forces created by symmetric fields within device. Forces are sensed and counteracted by Hall devices on excitation or control windings. Hall generators directly measure and provide compensating control of anu asymmetry, eliminating additional measurements needed for calibration feedback control loop.

An analytical solution for the magneto-electro-elastic bimorph beam forced vibrations problem

International Nuclear Information System (INIS)

Milazzo, A; Orlando, C; Alaimo, A

2009-01-01

Based on the Timoshenko beam theory and on the assumption that the electric and magnetic fields can be treated as steady, since elastic waves propagate very slowly with respect to electromagnetic ones, a general analytical solution for the transient analysis of a magneto-electro-elastic bimorph beam is obtained. General magneto-electric boundary conditions can be applied on the top and bottom surfaces of the beam, allowing us to study the response of the bilayer structure to electromagnetic stimuli. The model reveals that the magneto-electric loads enter the solution as an equivalent external bending moment per unit length and as time-dependent mechanical boundary conditions through the definition of the bending moment. Moreover, the influences of the electro-mechanic, magneto-mechanic and electromagnetic coupling on the stiffness of the bimorph stem from the computation of the beam equivalent stiffness constants. Free and forced vibration analyses of both multiphase and laminated magneto-electro-elastic composite beams are carried out to check the effectiveness and reliability of the proposed analytic solution

Effects of AC Electric Field on Small Laminar Nonpremixed Flames

KAUST Repository

Xiong, Yuan

2015-04-01

baseline case, leading to the formation of toroidal vortices. Increased residence time and heat recirculation inside the vortex resulted in appreciable formation of PAHs and soot near the nozzle exit. Decreased residence time along the jet axis through flow acceleration by the vortex led to a reduction in the soot volume fraction in the downstream sooting zone. Electromagnetic force generated by AC was proposed as a viable mechanism for the formation of the toroidal vortex. By varying applied AC in a wide range of frequency and voltage, several insta- bility modes were observed, including flicking flames, partial pinch-off of flames, and spinning flames. High speed imaging together with Mie scattering techniques were combined to reveal the flame dynamics as well as the flow structure inside the flames. Original steady toroidal vortices triggered by AC were noted to exhibit axisymmetric axial instability in the flicking and partial pinch-off modes and non-axisymmetric azimuthal instability in the spinning mode. Electrical measurements were also conducted simultaneously to identify the voltage, current, and electrical power responses. Integrated power was noted to be sensitive to indicate subtle variation of flames properties and to the occurrence of axial instability. Under low frequency AC forcing with electrical conditions not generating toroidal vortices, responses of flames were further investigated. Several nonlinear flame responses, including frequency doubling and tripling phenomena, were identified. Spectral analysis revealed that such nonlinear responses were attributed to the combined effects of triggering buoyancy-induced oscillation of the flame as well as the Lorenz force generated by applying AC. Phase delay behaviors between the applied voltage and the heat release rate (or flame size) were also studied to explore the potential of applying AC in controlling flame instability. It was found that the phase delay had large variations for AC frequency smaller than

Child Brides, Forced Marriage, and Partner Violence in America: Tip of an Iceberg Revealed.

Science.gov (United States)

McFarlane, Judith; Nava, Angeles; Gilroy, Heidi; Maddoux, John

2016-04-01

Forced marriage is a violation of human rights and thwarts personal safety and well-being. Child brides are at higher risk of intimate partner violence (IPV) and often are unable to effectively negotiate safe sex, leaving them vulnerable to sexually transmitted infections, including human immunodeficiency virus, and early pregnancy. The prevalence of forced marriage and child marriage in the United States is unknown. The intersection of forced marriage and child marriage and IPV is equally unknown. When 277 mothers who reported IPV to shelter or justice services were asked about a forced marriage attempt, frequency and severity of IPV, mental health status, and behavioral functioning of their child, 47 (17%) reported a forced marriage attempt with 45% of the women younger than 18 years of age at the time of the attempt. Among the 47 women, 11 (23%) reported death threats, 20 (43%) reported marriage to the person, and 28 (60%) reported a pregnancy. Women younger than 18 years reported more threats of isolation and economic deprivation associated with the attempt as well as pressure from parents to marry. Regardless of age, women experiencing a forced marriage attempt reported more intimate partner sexual abuse, somatization, and behavior problems for their children. Forced marriage attempts occurred to one in six women (17%) reporting IPV and are associated with worse functioning for mother and child. The frequent occurrence and associated effect of forced marriage attempts to maternal child functioning indicates routine assessment for a forced marriage attempt as part of comprehensive care for women reporting IPV.

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

Science.gov (United States)

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

2015-04-08

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

Electricity demand in Tunisia

International Nuclear Information System (INIS)

Gam, Imen; Ben Rejeb, Jaleleddine

2012-01-01

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.

Physical, optical and electrical properties of copper selenide (CuSe) thin films deposited by solution growth technique at room temperature

International Nuclear Information System (INIS)

Gosavi, S.R.; Deshpande, N.G.; Gudage, Y.G.; Sharma, Ramphal

2008-01-01

Copper selenide (CuSe) thin films are grown onto amorphous glass substrate from an aqueous alkaline medium using solution growth technique (SGT) at room temperature. The preparative parameters were optimized to obtain good quality of thin films. The as-deposited films were characterized for physical, optical and electrical properties. X-ray diffraction (XRD) pattern reveals that the films are polycrystalline in nature. Energy dispersive analysis by X-ray (EDAX) shows formation of stoichiometric CuSe compound. Uniform deposition of CuSe thin films on glass substrate was observed from scanning electron microscopy (SEM) and atomic force microscopy (AFM) micrographs. Average grain size was determined to 144.53 ± 10 nm using atomic force microscopy. The band gap was found to be 2.03 eV with direct band-to-band transition. Semi-conducting behaviour was observed from resistivity measurements. Ohmic behaviour was seen from I-V curve with good electrical conductivity

Atmospheric Electricity and Tethered Aerostats, Volume 2

Science.gov (United States)

1976-05-11

EASTERN TEST RANGE PATRICK AIR FORCE BASE, FLORIDA 11 MAY 1976 028 099 AFETR -TR-76-07 ATMOSPHERIC ELECTRICITY AND ~TETHERED AEROSTATS, VOLUME 11 Range...number) Atmospheric Electricity Lightning- Effects , Protection, Warning Balloons Systems Conducting & Nonconducting Tethers Potential Gradient Anomalies...if necessary and Identify by block number) Part A, "Atmospheric Electrical Effects of and on Tethered Balloon Systems," by Latham includes airborne

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.

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:…

Reorientation of single-wall carbon nanotubes in negative anisotropy liquid crystals by an electric field

Directory of Open Access Journals (Sweden)

Amanda García-García

2016-06-01

Full Text Available Single-wall carbon nanotubes (SWCNT are anisotropic nanoparticles that can cause modifications in the electrical and electro-optical properties of liquid crystals. The control of the SWCNT concentration, distribution and reorientation in such self-organized fluids allows for the possibility of tuning the liquid crystal properties. The alignment and reorientation of CNTs are studied in a system where the liquid crystal orientation effect has been isolated. Complementary studies including Raman spectroscopy, microscopic inspection and impedance studies were carried out. The results reveal an ordered reorientation of the CNTs induced by an electric field, which does not alter the orientation of the liquid crystal molecules. Moreover, impedance spectroscopy suggests a nonnegligible anchoring force between the CNTs and the liquid crystal molecules.

Concept for room temperature single-spin tunneling force microscopy with atomic spatial resolution

Science.gov (United States)

Payne, Adam

A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy (AFM) system noise. The results show that the approach could provide single-spin measurement of electrically isolated defect states with atomic spatial resolution at room temperature.

Atomic-resolution single-spin magnetic resonance detection concept based on tunneling force microscopy

Science.gov (United States)

Payne, A.; Ambal, K.; Boehme, C.; Williams, C. C.

2015-05-01

A study of a force detected single-spin magnetic resonance measurement concept with atomic spatial resolution is presented. The method is based upon electrostatic force detection of spin-selection rule controlled single-electron tunneling between two electrically isolated paramagnetic states. Single-spin magnetic resonance detection is possible by measuring the force detected tunneling charge noise on and off spin resonance. Simulation results of this charge noise, based upon physical models of the tunneling and spin physics, are directly compared to measured atomic force microscopy system noise. The results show that the approach could provide single-spin measurement of electrically isolated qubit states with atomic spatial resolution at room temperature.

Axial force measurement for esophageal function testing

DEFF Research Database (Denmark)

Gravesen, Flemming Holbæk; Funch-Jensen, Peter; Gregersen, Hans

2009-01-01

force (force in radial direction) whereas the bolus moves along the length of esophagus in a distal direction. Force measurements in the longitudinal (axial) direction provide a more direct measure of esophageal transport function. The technique used to record axial force has developed from external...... force transducers over in-vivo strain gauges of various sizes to electrical impedance based measurements. The amplitude and duration of the axial force has been shown to be as reliable as manometry. Normal, as well as abnormal, manometric recordings occur with normal bolus transit, which have been...... documented using imaging modalities such as radiography and scintigraphy. This inconsistency using manometry has also been documented by axial force recordings. This underlines the lack of information when diagnostics are based on manometry alone. Increasing the volume of a bag mounted on a probe...

Piezo-generated charge mapping revealed through direct piezoelectric force microscopy.

Science.gov (United States)

Gomez, A; Gich, M; Carretero-Genevrier, A; Puig, T; Obradors, X

2017-10-24

While piezoelectric and ferroelectric materials play a key role in many everyday applications, there are still a number of open questions related to their physics. To enhance our understanding of piezoelectrics and ferroelectrics, nanoscale characterization is essential. Here, we develop an atomic force microscopy based mode that obtains a direct quantitative analysis of the piezoelectric coefficient d 33 . We report nanoscale images of piezogenerated charge in a thick single crystal of periodically poled lithium niobate (PPLN), a bismuth ferrite (BiFO 3 ) thin film, and lead zirconate titanate (PZT) by applying a force and recording the current produced by these materials. The quantification of d 33 coefficients for PPLN (14 ± 3 pC per N) and BFO (43 ± 6 pC per N) is in agreement with the values reported in the literature. Even stronger evidence of the reliability of the method is provided by an equally accurate measurement of the significantly larger d 33 of PZT.

Pragmatic analysis of the electric submerged arc furnace continuum

Science.gov (United States)

Karalis, K.; Karkalos, N.; Antipas, G. S. E.; Xenidis, A.

2017-09-01

A transient mathematical model was developed for the description of fluid flow, heat transfer and electromagnetic phenomena involved in the production of ferronickel in electric arc furnaces. The key operating variables considered were the thermal and electrical conductivity of the slag and the shape, immersion depth and applied electric potential of the electrodes. It was established that the principal stimuli of the velocities in the slag bath were the electric potential and immersion depth of the electrodes and the thermal and electrical conductivities of the slag. Additionally, it was determined that, under the set of operating conditions examined, the maximum slag temperature ranged between 1756 and 1825 K, which is in accordance with industrial measurements. Moreover, it was affirmed that contributions to slag stirring due to Lorentz forces and momentum forces due to the release of carbon monoxide bubbles from the electrode surface were negligible.

High-resolution electrical resistivity and aeromagnetic imaging reveal the causative fault of the 2009 Mw 6.0 Karonga, Malawi earthquake

Science.gov (United States)

Kolawole, F.; Atekwana, E. A.; Laó-Dávila, D. A.; Abdelsalam, M. G.; Chindandali, P. R.; Salima, J.; Kalindekafe, L.

2018-05-01

Seismic events of varying magnitudes have been associated with ruptures along unknown or incompletely mapped buried faults. The 2009 Mw 6.0 Karonga, Malawi earthquake caused a surface rupture length of 14-18 km along a single W-dipping fault [St. Mary Fault (SMF)] on the hanging wall of the North Basin of the Malawi Rift. Prior to this earthquake, there was no known surface expression or knowledge of the presence of this fault. Although the earthquake damage zone is characterized by surface ruptures and coseismic liquefaction-induced sand blows, the origin of the causative fault and the near-surface structure of the rupture zone are not known. We used high-resolution aeromagnetic and electrical resistivity data to elucidate the relationship between surface rupture locations and buried basement structures. We also acquired electrical resistivity tomography (ERT) profiles along and across the surface rupture zone to image the near-surface structure of the damaged zone. We applied mathematical derivative filters to the aeromagnetic data to enhance basement structures underlying the rupture zone and surrounding areas. Although several magnetic lineaments are visible in the basement, mapped surface ruptures align with a single 37 km long, 148°-162°—striking magnetic lineament, and is interpreted as the ruptured normal fault. Inverted ERT profiles reveal three regional geoelectric layers which consist of 15 m thick layer of discontinuous zones of high and low resistivity values, underlain by a 27 m thick zone of high electrical resistivity (up to 100 Ω m) and a basal layer of lower resistivity (1.0-6.0 Ω m) extending from 42 m depth downwards (the maximum achieved depth of investigation). The geoelectric layers are truncated by a zone of electrical disturbance (electrical mélange) coinciding with areas of coseismic surface rupturing and sediment liquefaction along the ruptured. Our study shows that the 2009 Karonga earthquake was associated with the partial

Outlook for electricity markets 2005-2006 : an energy market assessment

International Nuclear Information System (INIS)

2005-06-01

The National Energy Board monitors the supply of electricity as well as its demand in both domestic and export markets. This document was produced in response to a survey with power generation, transmission and distribution companies, marketers, end-users, environmental groups and government agencies who demonstrated the need for more short-and medium-term energy market assessments to supplement the Board's longer term energy analysis. It on the short-term (2005-2006) issues that can have a long-term effect on the electricity sector. The document presents an analysis of Canadian electricity markets with particular focus on the main drivers affecting current trends in generation, demand, prices, infrastructure additions, and inter-regional and international trade. Current restructuring activities in Canada's electricity industry were also described along with the close relationship between the electricity sectors in Canada and the United States which stems from the integrated nature of the North American power grid. A regional market assessment and a summary was provided for each of Canada's provinces and territories with reference to market structure and current market developments. It was revealed that Canada's electricity markets have developed along provincial or regional boundaries. Utilities have tried to provide adequate and reliable electricity supply, environmental sustainability and acceptable electricity prices. It was concluded that supply is adequate in all regions in the short-term, but tight supply conditions could emerge as early as 2007. Alternative and renewable resource and demand management are becoming more important in addressing air quality issues and supply adequacy. Since uncertainty may delay investment and development of new infrastructure, utilities may be forced to increase electricity prices. It was suggested that interprovincial energy transfers should be further explored. Five recommendations were presented to address the key

Demonstration of motion control of ZrO2 microparticles in uniform/non-uniform electric field

Science.gov (United States)

Onishi, Genki; Trung, Ngo Nguyen Chi; Matsutani, Naoto; Nakayama, Tadachika; Suzuki, Tsuneo; Suematsu, Hisayuki; Niihara, Koichi

2018-02-01

This study aims to elucidate the mechanism that drives dielectric microparticles under an electric field. The driving of microstructures is affected by various electrical phenomena occurring at the same time such as surface potential, polarization, and electrostatic force. It makes the clarification of the driving mechanism challenging. A simple experimental system was used to observe the behavior of spherical ZrO2 microparticles in a nonaqueous solution under an electric field. The results suggest that the mechanism that drives the ZrO2 microparticles under an electric field involved the combination of an electric image force, a gradient force, and the contact charging phenomenon. A method is proposed to control the motion of micro- and nanostructures in further study and applications.

Application of thermo-electromotive force and electric resistance measuring methods to researching phase transformations in Zr1Nb alloy

International Nuclear Information System (INIS)

Klimenko, S.P.; Gritsina, V.M.; Petel'guzov, I.A.; Chernyaeva, T.P.

2007-01-01

The paper determines the applicability areas of different methods for the study of structural phase transformations in a Zr+1Nb alloy, which is extensively used in reactor construction; production and fabrication of products from Zr+1Nb is currently developed in Ukraine. Electromotive force and electric resistance were measured to study structural phase transformations of Zr+1Nb fuel rod tubes based on calciumthermal zirconium (Zr1Nb). It was established that changes in electric resistance clearly show the beginning of a massive α → β transition at ∼ 750 degree C and the end of α → β transition at ∼ 950 degree C, whereas measurement of thermo-e.m.f. in the samples subjected to successive 3-hour step annealing in the temperature range from 300 to 700 degree C allows the temperature of monotectoid transformation to be found. For sample Zr1Nb batches the temperature of monotectoid transformation is (620±7) degree C. The measurement results are consistent with the similar studies carried out on Zr+1Nb fuel rod tubes based on electrolytic zirconium (E110), for which the temperature of monotectoid transformation is equal to ∼ 610 degree C

Nonconservative current-induced forces: A physical interpretation

Directory of Open Access Journals (Sweden)

Tchavdar N. Todorov

2011-10-01

Full Text Available We give a physical interpretation of the recently demonstrated nonconservative nature of interatomic forces in current-carrying nanostructures. We start from the analytical expression for the curl of these forces, and evaluate it for a point defect in a current-carrying system. We obtain a general definition of the capacity of electrical current flow to exert a nonconservative force, and thus do net work around closed paths, by a formal noninvasive test procedure. Second, we show that the gain in atomic kinetic energy over time, generated by nonconservative current-induced forces, is equivalent to the uncompensated stimulated emission of directional phonons. This connection with electron–phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.

THE TRACTION ELECTRIC OPERATION AND ITS EXPLOITATION ABILITIES

Directory of Open Access Journals (Sweden)

V. M. Bezruchenko

2011-04-01

Full Text Available The possibilities of asynchronous traction electric motor drive are considered at the certain coupling mass taking into account the coupling restrictions. A variant of using the regulation law for electric motor drive allowing realizing traction force more rationally is offered. The possibility of reaching the speeds to 220 km/h for electric locomotive DS3 is shown

Electricity : Italian style

International Nuclear Information System (INIS)

Murray, L.

2007-01-01

Italy's electricity system was described. Italy relies on outside sources for between 10 and 15 per cent of its electricity supply. Most Italians use gas, wood stoves and fossil fuels, and are conservative about lighting. Electricity costs more in Italy than in any other European country. Italy made the decision to decommission its nuclear power stations after Chernobyl. In 2005, Italy's largest utility group signed a memorandum of understanding ensuring that they would contract energy from France's nuclear reactors. Italy is now financing and managing projects in Russia and eastern Europe, and has strengthened its ties in Spain and the Netherlands. Although Italy is intent on producing its own power, the perceptions of health hazards from electricity towers cause citizens to strongly protest new installations. It was concluded that rising energy prices may force Italians to reconsider the use of alternative energy sources. 3 figs

Electric Potential and Electric Field Imaging with Applications

Science.gov (United States)

Generazio, Ed

2016-01-01

The technology and techniques for remote quantitative imaging of electrostatic potentials and electrostatic fields in and around objects and in free space is presented. Electric field imaging (EFI) technology may be applied to characterize intrinsic or existing electric potentials and electric fields, or an externally generated electrostatic field may be used for (illuminating) volumes to be inspected with EFI. The baseline sensor technology, electric field sensor (e-sensor), and its construction, optional electric field generation (quasistatic generator), and current e-sensor enhancements (ephemeral e-sensor) are discussed. Demonstrations for structural, electronic, human, and memory applications are shown. This new EFI capability is demonstrated to reveal characterization of electric charge distribution, creating a new field of study that embraces areas of interest including electrostatic discharge mitigation, crime scene forensics, design and materials selection for advanced sensors, dielectric morphology of structures, inspection of containers, inspection for hidden objects, tether integrity, organic molecular memory, and medical diagnostic and treatment efficacy applications such as cardiac polarization wave propagation and electromyography imaging.

A MEMS sensor for microscale force measurements

International Nuclear Information System (INIS)

Majcherek, S; Aman, A; Fochtmann, J

2016-01-01

This paper describes the development and testing of a new MEMS-based sensor device for microscale contact force measurements. A special MEMS cell was developed to reach higher lateral resolution than common steel-based load cells with foil-type strain gauges as mechanical-electrical converters. The design provided more than one normal force measurement point with spatial resolution in submillimeter range. Specific geometric adaption of the MEMS-device allowed adjustability of its measurement range between 0.5 and 5 N. The thin film nickel-chromium piezo resistors were used to achieve a mechanical-electrical conversion. The production process was realized by established silicon processing technologies such as deep reactive ion etching and vapor deposition (sputtering). The sensor was tested in two steps. Firstly, the sensor characteristics were carried out by application of defined loads at the measurement points by a push-pull tester. As a result, the sensor showed linear behavior. A measurement system analysis (MSA1) was performed to define the reliability of the measurement system. The measured force values had the maximal relative deviation of 1% to average value of 1.97 N. Secondly, the sensor was tested under near-industrial conditions. In this context, the thermal induced relaxation behavior of the electrical connector contact springs was investigated. The handling of emerging problems during the characterization process of the sensor is also described. (paper)

Development of a Wind Directly Forced Heat Pump and Its Efficiency Analysis

Directory of Open Access Journals (Sweden)

Ching-Song Jwo

2013-01-01

Full Text Available The requirements of providing electric energy through the wind-forced generator to the heat pump for water cooling and hot water heating grow significantly by now. This study proposes a new technique to directly adopt the wind force to drive heat pump systems, which can effectively reduce the energy conversion losses during the processes of wind force energy converting to electric energy and electric energy converting to kinetic energy. The operation of heat pump system transfers between chiller and heat that are controlled by a four-way valve. The theoretical efficiency of the traditional method, whose heat pump is directly forced by wind, is 42.19%. The experimental results indicated average value for cool water producing efficiency of 54.38% in the outdoor temperature of 35°C and the indoor temperature of 25°C and the hot water producing efficiency of 52.25% in the outdoor temperature and the indoor temperature both of 10°C. We proposed a method which can improve the efficiency over 10% in both cooling and heating.

Synergistic effect of Ag nanoparticle-decorated graphene oxide and carbon fiber on electrical actuation of polymeric shape memory nanocomposites

International Nuclear Information System (INIS)

Lu, Haibao; Leng, Jinsong; Du, Shanyi; Liang, Fei; Gou, Jihua

2014-01-01

This study reports an effective approach of significantly improving electrical properties and recovery performance of shape memory polymer (SMP) nanocomposite, of which its shape recovery was triggered by electrically resistive Joule heating. Reduced graphene oxide (GOs) self-assembled and grafted onto carbon fiber, were used to enhance the interfacial bonding with the SMP matrix via van der Waals force and covalent bond, respectively. A layer of Ag nanoparticles was synthesized from Ag + solution and chemically deposited onto GO assemblies. These Ag nanoparticles were expected to bridge the gap between GO and improve the electrical conductivity. The experimental results reveal that the electrical conductivity of the SMP nanocomposite was significantly improved via the synergistic effect between Ag nanoparticle-decorated GO and carbon fiber. Finally, the electrically induced shape memory effect of the SMP nanocomposite was achieved, and the temperature distribution in the SMP nanocomposites was recorded and monitored. An effective approach was demonstrated to produce the electro-activated SMP nanocomposites and the resistive Joule heating was viable at a low electrical voltage below 10 V. (paper)

Electricity sector human resources review

Energy Technology Data Exchange (ETDEWEB)

Facette, J. [Canadian Association of Technicians and Technologists (Canada)

2005-07-01

The electricity industry is expanding, with new supply and infrastructure development equivalent to 35 per cent of existing capacity over the next 20 years. This paper examines the preliminary results of a human resources sector review providing industry specific labor force data. The key objectives of the review were to develop detailed industry profiles, identify root causes of human resources issues, identify industry best practices and develop a human resources strategy for the Canadian electricity sector. Estimates of current employment were provided, with age of employees, retirement projections, regional projections and estimated supply/demand gaps. Current shortages were identified, including wind energy technicians. The paper also identified a declining Canadian born labor force and a concurrent dependence on immigrants. A project research methodology was provided with a list of participating major employers. tabs., figs.

Enhanced policies for the improvement of electricity efficiencies

International Nuclear Information System (INIS)

Blok, Kornelis

2005-01-01

Energy-efficiency improvement is considered as an important option to limit greenhouse gas emissions. In this paper, the possibilities to implement new policies to improve the efficiency of electricity end-use are explored. The following policy actions are considered: - introduction of a '1 W standard' for standby power consumption of appliances;- incremental standards for large electric appliances;- design guidelines for small electric appliances;- a technology-forcing standard for lighting;- a motor-drive program;- a program directed at the reduction of electricity use during empty-office hours;- actual energy performance requirements for service-sector buildings. The implementation of these programs will contribute substantially to reaching greenhouse gas emission targets in the European Union (total estimated effect to be 200-350 Mton CO 2 emission reduction in the year 2020). However, to reach these targets a very substantial effort is required, both in terms of policy ambition, force of the applied instruments, and implementation efforts. In the case of electric appliances, regulatory instruments may need wider application. And, in order to attain the substantial potential savings in motor-drive systems, an effort comparable to the effort to promote renewable electricity in the European Union may be both justified and necessary

Effect of polarization force on the Jeans instability of self-gravitating dusty plasma

International Nuclear Information System (INIS)

Prajapati, R.P.

2011-01-01

The effect of polarization force acting on massive charged dust grains is investigated analytically on the Jeans instability of self-gravitating dusty plasma. The gravitational force acting on the massive negatively charged interstellar dust grains are considered in presence of both electrical and polarization forces. The basic equations of the problem are formulated and a general dispersion relation is obtained using plane wave approximation in low frequency wave mode. The effect of polarization force in the dispersion relation of the problem, condition of the Jeans instability and expression of the critical Jeans wave number is examined. The unstable growing modes due to self-gravitational force are studied in the situation when polarization force on the dust grain exceeds over the electrical force in magnitude. It is observed that the polarization force increases the growth rate of the system. -- Highlights: → Jeans instability of gravitating dusty plasma with polarization force is investigated. → The fundamental Jeans instability criterion is modified due to polarization effect. → The critical Jeans length decreases due to increase in polarization force. → Polarization force destabilizes the unstable Jeans mode. → The collapsing of interstellar dusty cloud is discussed.

Force Measurements on a VAWT Blade in Parked Conditions

Directory of Open Access Journals (Sweden)

Anders Goude

2017-11-01

Full Text Available The forces on a turbine at extreme wind conditions when the turbine is parked is one of the most important design cases for the survivability of a turbine. In this work, the forces on a blade and its support arms have been measured on a 12 kW straight-bladed vertical axis wind turbine at an open site. Two cases are tested: one during electrical braking of the turbine, which allows it to rotate slowly, and one with the turbine mechanically fixed with the leading edge of the blade facing the main wind direction. The force variations with respect to wind direction are investigated, and it is seen that significant variations in forces depend on the wind direction. The measurements show that for the fixed case, when subjected to the same wind speed, the forces are lower when the blade faces the wind direction. The results also show that due to the lower forces at this particular wind direction, the average forces for the fixed blade are notably lower. Hence, it is possible to reduce the forces on a turbine blade, simply by taking the dominating wind direction into account when the turbine is parked. The measurements also show that a positive torque is generated from the blade for most wind directions, which causes the turbine to rotate in the electrically-braked case. These rotations will cause increased fatigue loads on the turbine blade.

Study and characterization of the irreversible transformation of electrically stressed planar Ti/TiO{sub x}/Ti junctions

Energy Technology Data Exchange (ETDEWEB)

Guillaume, N.; Puyoo, E., E-mail: etienne.puyoo@insa-lyon.fr; Le Berre, M.; Albertini, D.; Baboux, N.; Chevalier, C.; Ayadi, K.; Grégoire, J.; Gautier, B.; Calmon, F. [Institut des Nanotechnologies de Lyon, Université de Lyon, INL UMR 5270, CNRS, INSA de Lyon, Villeurbanne F-69621 (France)

2015-10-14

We investigate the properties and characteristics of planar Ti/TiO{sub x}/Ti junctions, which consist of transverse TiO{sub x} lines drawn on Ti test patterns. Junctions are elaborated by means of local anodic oxidation using atomic force microscopy. An irreversible morphological transformation occurring in a reproducible manner is observed when these planar junctions are electrically stressed under ambient atmosphere. Structural and chemical analyses based on transmission electron microscopy techniques reveal the extension of the initial amorphous TiO{sub x} into a crystalline rutile phase. This irreversible transformation is proven to vanish completely if the electrical stress occurs under vacuum atmosphere. Finally, we carry out temperature dependent electrical measurements in order to elucidate their conduction mechanism: Schottky emission above an ultra-low potential barrier is assumed to dominate under vacuum atmosphere whereas ionic conduction seems to prevail in air.

A hybrid model for electricity spot prices

International Nuclear Information System (INIS)

Anderson, C.L.D.

2004-01-01

Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach

A hybrid model for electricity spot prices

Energy Technology Data Exchange (ETDEWEB)

Anderson, C.L.D.

2004-07-01

Electricity prices were highly regulated prior to the deregulation of the electric power industry. Prices were predictable, allowing generators and wholesalers to calculate their production costs and revenues. With deregulation, electricity has become the most volatile of all commodities. Electricity must be consumed as soon as it is generated due to the inability to store it in any sufficient quantity. Economic uncertainty exists because the supply of electricity cannot shift as quickly as the demand, which is highly variable. When demand increases quickly, the price must respond. Therefore, price spikes occur that are orders of magnitude higher than the base electricity price. This paper presents a robust and realistic model for spot market electricity prices used to manage risk in volatile markets. The model is a hybrid of a top down data driven method commonly used for financial applications, and a bottom up system driven method commonly used in regulated electricity markets. The advantage of the model is that it incorporates primary system drivers and demonstrates their effects on final prices. The 4 primary modules of the model are: (1) a model for forced outages, (2) a model for maintenance outages, (3) an electrical load model, and (4) a price model which combines the results of the previous 3 models. The performance of each model was tested. The forced outage model is the first of its kind to simulate the system on an aggregate basis using Weibull distributions. The overall spot price model was calibrated to, and tested with, data from the electricity market in Pennsylvania, New Jersey and Maryland. The model performed well in simulated market prices and adapted readily to changing system conditions and new electricity markets. This study examined the pricing of derivative contracts on electrical power. It also compared a range of portfolio scenarios using a Cash Flow at Risk approach.

Force-activatable biosensor enables single platelet force mapping directly by fluorescence imaging.

Science.gov (United States)

Wang, Yongliang; LeVine, Dana N; Gannon, Margaret; Zhao, Yuanchang; Sarkar, Anwesha; Hoch, Bailey; Wang, Xuefeng

2018-02-15

Integrin-transmitted cellular forces are critical for platelet adhesion, activation, aggregation and contraction during hemostasis and thrombosis. Measuring and mapping single platelet forces are desired in both research and clinical applications. Conventional force-to-strain based cell traction force microscopies have low resolution which is not ideal for cellular force mapping in small platelets. To enable platelet force mapping with submicron resolution, we developed a force-activatable biosensor named integrative tension sensor (ITS) which directly converts molecular tensions to fluorescent signals, therefore enabling cellular force mapping directly by fluorescence imaging. With ITS, we mapped cellular forces in single platelets at 0.4µm resolution. We found that platelet force distribution has strong polarization which is sensitive to treatment with the anti-platelet drug tirofiban, suggesting that the ITS force map can report anti-platelet drug efficacy. The ITS also calibrated integrin molecular tensions in platelets and revealed two distinct tension levels: 12-54 piconewton (nominal values) tensions generated during platelet adhesion and tensions above 54 piconewton generated during platelet contraction. Overall, the ITS is a powerful biosensor for the study of platelet mechanobiology, and holds great potential in antithrombotic drug development and assessing platelet activity in health and disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Predicting muscle forces of individuals with hemiparesis following stroke

Directory of Open Access Journals (Sweden)

Maladen Ryan

2008-02-01

Full Text Available Abstract Background Functional electrical stimulation (FES has been used to improve function in individuals with hemiparesis following stroke. An ideal functional electrical stimulation (FES system needs an accurate mathematical model capable of designing subject and task-specific stimulation patterns. Such a model was previously developed in our laboratory and shown to predict the isometric forces produced by the quadriceps femoris muscles of able-bodied individuals and individuals with spinal cord injury in response to a wide range of clinically relevant stimulation frequencies and patterns. The aim of this study was to test our isometric muscle force model on the quadriceps femoris, ankle dorsiflexor, and ankle plantar-flexor muscles of individuals with post-stroke hemiparesis. Methods Subjects were seated on a force dynamometer and isometric forces were measured in response to a range of stimulation frequencies (10 to 80-Hz and 3 different patterns. Subject-specific model parameter values were obtained by fitting the measured force responses from 2 stimulation trains. The model parameters thus obtained were then used to obtain predicted forces for a range of frequencies and patterns. Predicted and measured forces were compared using intra-class correlation coefficients, r2 values, and model error relative to the physiological error (variability of measured forces. Results Results showed excellent agreement between measured and predicted force-time responses (r2 >0.80, peak forces (ICCs>0.84, and force-time integrals (ICCs>0.82 for the quadriceps, dorsiflexor, and plantar-fexor muscles. The model error was within or below the +95% confidence interval of the physiological error for >88% comparisons between measured and predicted forces. Conclusion Our results show that the model has potential to be incorporated as a feed-forward controller for predicting subject-specific stimulation patterns during FES.

Forced reptation revealed by chain pull-out simulations.

Science.gov (United States)

Bulacu, Monica; van der Giessen, Erik

2009-08-14

We report computation results obtained from extensive molecular dynamics simulations of tensile disentanglement of connector chains placed at the interface between two polymer bulks. Each polymer chain (either belonging to the bulks or being a connector) is treated as a sequence of beads interconnected by springs, using a coarse-grained representation based on the Kremer-Grest model, extended to account for stiffness along the chain backbone. Forced reptation of the connectors was observed during their disentanglement from the bulk chains. The extracted chains are clearly seen following an imaginary "tube" inside the bulks as they are pulled out. The entropic and energetic responses to the external deformation are investigated by monitoring the connector conformation tensor and the modifications of the internal parameters (bonds, bending, and torsion angles along the connectors). The work needed to separate the two bulks is computed from the tensile force induced during debonding in the connector chains. The value of the work reached at total separation is considered as the debonding energy G. The most important parameters controlling G are the length (n) of the chains placed at the interface and their areal density. Our in silico experiments are performed at relatively low areal density and are disregarded if chain scission occurs during disentanglement. As predicted by the reptation theory, for this pure pull-out regime, the power exponent from the scaling G proportional, variant n(a) is a approximately 2, irrespective of chain stiffness. Small variations are found when the connectors form different number of stitches at the interface, or when their length is randomly distributed in between the two bulks. Our results show that the effects of the number of stitches and of the randomness of the block lengths have to be considered together, especially when comparing with experiments where they cannot be controlled rigorously. These results may be significant for

Electric-utility DSM programs in a competitive market

Energy Technology Data Exchange (ETDEWEB)

Hirst, E.

1994-04-01

During the past few years, the costs and effects of utility demand-side management (DSM) programs have grown sharply. In 1989, US electric utilities spent 0.5% of revenues on such programs and cut total electricity consumption by 0.6%. By 1992, these numbers had increased to 1.3% and 1.2%, respectively. Utility projections, as of early 1993, of DSM expenditures and energy savings for 1997 were 1.7% and 2.5%, respectively. Whether this projected growth comes to pass may depend on current debates about deregulation of, and increased competition in, the electric-utility industry. This report examines the factors likely to affect utility DSM programs in a more competitive environment. The electric-utility industry faces two forces that may conflict with each other. One is the pressure to open up both wholesale and retail markets for competition. The net effect of such competition, especially at the retail level, would have much greater emphasis on electricity prices and less emphasis on energy services. Such an outcome would force a sharp reduction in the scale of DSM programs that are funded by customers in general. The second force is increased concern about environmental quality and global warming. Because utilities are major contributors to US carbon dioxide emissions, the Administration`s Climate Change Action Plan calls on utilities to reduce such emissions. DSM programs are one key way to do that and, in the process, to cut customer electric bills and improve economic productivity. This report discusses the forms of competition and how they might affect DSM programs. It examines the important roles that state regulatory commissions could play to affect retail competition and utility DSM programs. The report also considers the effects of DSM programs on retail electricity prices.

Electrical stress and strain in lunar regolith simulants

Science.gov (United States)

Marshall, J.; Richard, D.; Davis, S.

2011-11-01

Experiments to entrain dust with electrostatic and fluid-dynamic forces result in particulate clouds of aggregates rather than individual dust grains. This is explained within the framework of Griffith-flaw theory regarding the comminution/breakage of weak solids. Physical and electrical inhomogeneities in powders are equivalent to microcracks in solids insofar as they facilitate failure at stress risers. Electrical charging of powders induces bulk sample stresses similar to mechanical stresses experienced by strong solids, depending on the nature of the charging. A powder mass therefore "breaks" into clumps rather than separating into individual dust particles. This contrasts with the expectation that electrical forces on the Moon will eject a submicron population of dust from the regolith into the exosphere. A lunar regolith will contain physical and electrostatic inhomogeneities similar to those in most charged powders.

Electrical characterization of ZnO nanorods

Energy Technology Data Exchange (ETDEWEB)

Schlenker, E.; Bakin, A.; Postels, B.; Mofor, A.C.; Wehmann, H.H.; Waag, A. [Institute of Semiconductor Technology, Technical University Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig (Germany); Weimann, T.; Hinze, P. [Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig (Germany)

2007-05-15

Zinc oxide (ZnO) nanorods were grown by a wet chemical approach and by vapor phase transport. To explore the electrical properties of individual nanostructures current-voltage (I-V) characteristics were obtained by using an atomic force microscope (AFM) with a conductive tip or by detaching the nanorods from the growth substrate, transferring them to an isolating substrate and contacting them with evaporated Ti/Au electrodes patterned by electron-beam lithography. The AFM-approach only yields a Schottky diode behavior, while the Ti/Au forms ohmic contacts to the ZnO. For the latter method the obtained I-V curves reveal a resistivity of the nanorods in the order of 10{sup -5} {omega} cm which is unusually low for undoped ZnO. We therefore assume the existence of a highly conductive surface channel. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Electric organ discharges and electric images during electrolocation

Science.gov (United States)

Assad, C.; Rasnow, B.; Stoddard, P. K.

1999-01-01

Weakly electric fish use active electrolocation - the generation and detection of electric currents - to explore their surroundings. Although electrosensory systems include some of the most extensively understood circuits in the vertebrate central nervous system, relatively little is known quantitatively about how fish electrolocate objects. We believe a prerequisite to understanding electrolocation and its underlying neural substrates is to quantify and visualize the peripheral electrosensory information measured by the electroreceptors. We have therefore focused on reconstructing both the electric organ discharges (EODs) and the electric images resulting from nearby objects and the fish's exploratory behaviors. Here, we review results from a combination of techniques, including field measurements, numerical and semi-analytical simulations, and video imaging of behaviors. EOD maps are presented and interpreted for six gymnotiform species. They reveal diverse electric field patterns that have significant implications for both the electrosensory and electromotor systems. Our simulations generated predictions of the electric images from nearby objects as well as sequences of electric images during exploratory behaviors. These methods are leading to the identification of image features and computational algorithms that could reliably encode electrosensory information and may help guide electrophysiological experiments exploring the neural basis of electrolocation.

Pressure-induced americium valence fluctuations revealed by electrical resistivity

Czech Academy of Sciences Publication Activity Database

Kolomiets, A. V.; Griveau, J.C.; Heathman, S.; Shick, Alexander; Wastin, F.; Faure, P.; Klosek, V.; Genestier, C.; Baclet, N.; Havela, L.

2008-01-01

Roč. 82, č. 5 (2008), 57007/1-57007/5 ISSN 0295-5075 R&D Projects: GA MŠk OC 144; GA ČR GA202/07/0644 Grant - others:EU(XE) RITA -CT-2006-026176 Institutional research plan: CEZ:AV0Z10100520 Keywords : electrical conductivity * strong electron interactions * electronic structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.203, year: 2008

Influence of ion pairing in ionic liquids on electrical double layer structures and surface force using classical density functional approach.

Science.gov (United States)

Ma, Ke; Forsman, Jan; Woodward, Clifford E

2015-05-07

We explore the influence of ion pairing in room temperature ionic liquids confined by planar electrode surfaces. Using a coarse-grained model for the aromatic ionic liquid [C4MIM(+)][BF4 (-)], we account for an ion pairing component as an equilibrium associating species within a classical density functional theory. We investigated the resulting structure of the electrical double layer as well as the ensuing surface forces and differential capacitance, as a function of the degree of ion association. We found that the short-range structure adjacent to surfaces was remarkably unaffected by the degree of ion pairing, up to several molecular diameters. This was even the case for 100% of ions being paired. The physical implications of ion pairing only become apparent in equilibrium properties that depend upon the long-range screening of charges, such as the asymptotic behaviour of surface forces and the differential capacitance, especially at low surface potential. The effect of ion pairing on capacitance is consistent with their invocation as a source of the anomalous temperature dependence of the latter. This work shows that ion pairing effects on equilibrium properties are subtle and may be difficult to extract directly from simulations.

Effect of tendon vibration during wide-pulse neuromuscular electrical stimulation (NMES) on muscle force production in people with spinal cord injury (SCI).

Science.gov (United States)

Bochkezanian, Vanesa; Newton, Robert U; Trajano, Gabriel S; Vieira, Amilton; Pulverenti, Timothy S; Blazevich, Anthony J

2018-02-13

Neuromuscular electrical stimulation (NMES) is commonly used in skeletal muscles in people with spinal cord injury (SCI) with the aim of increasing muscle recruitment and thus muscle force production. NMES has been conventionally used in clinical practice as functional electrical stimulation (FES), using low levels of evoked force that cannot optimally stimulate muscular strength and mass improvements, and thus trigger musculoskeletal changes in paralysed muscles. The use of high intensity intermittent NMES training using wide-pulse width and moderate-intensity as a strength training tool could be a promising method to increase muscle force production in people with SCI. However, this type of protocol has not been clinically adopted because it may generate rapid muscle fatigue and thus prevent the performance of repeated high-intensity muscular contractions in paralysed muscles. Moreover, superimposing patellar tendon vibration onto the wide-pulse width NMES has been shown to elicit further increases in impulse or, at least, reduce the rate of fatigue in repeated contractions in able-bodied populations, but there is a lack of evidence to support this argument in people with SCI. Nine people with SCI received two NMES protocols with and without superimposing patellar tendon vibration on different days (i.e. STIM and STIM+vib), which consisted of repeated 30 Hz trains of 58 wide-pulse width (1000 μs) symmetric biphasic pulses (0.033-s inter-pulse interval; 2 s stimulation train; 2-s inter-train interval) being delivered to the dominant quadriceps femoris. Starting torque was 20% of maximal doublet-twitch torque and stimulations continued until torque declined to 50% of the starting torque. Total knee extensor impulse was calculated as the primary outcome variable. Total knee extensor impulse increased in four subjects when patellar tendon vibration was imposed (59.2 ± 15.8%) but decreased in five subjects (- 31.3 ± 25.7%). However, there were no

Local muscle metabolic demand induced by neuromuscular electrical stimulation and voluntary contractions at different force levels: a NIRS study

Directory of Open Access Journals (Sweden)

Makii Muthalib

2016-06-01

Full Text Available Functional Muscle metabolic demand during contractions evoked by neuromuscular electrical stimulation (NMES has been consistently documented to be greater than voluntary contractions (VOL at the same force level (10-50% maximal voluntary contraction-MVC. However, we have shown using a near-infrared spectroscopy (NIRS technique that local muscle metabolic demand is similar between NMES and VOL performed at MVC levels, thus controversy exists. This study therefore compared biceps brachii muscle metabolic demand (tissue oxygenation index-TOI and total hemoglobin volume-tHb during a 10s isometric contraction of the elbow flexors between NMES (stimulation frequency of 30Hz and current level to evoke 30% MVC and VOL at 30% MVC (VOL-30%MVC and MVC (VOL-MVC level in 8 healthy men (23-33-y. Greater changes in TOI and tHb induced by NMES than VOL-30%MVC confirm previous studies of a greater local metabolic demand for NMES than VOL at the same force level. The same TOI and tHb changes for NMES and VOL-MVC suggest that local muscle metabolic demand and intramuscular pressure were similar between conditions. In conclusion, these findings indicate that NMES induce a similar local muscle metabolic demand as that of maximal VOL.

Local Muscle Metabolic Demand Induced by Neuromuscular Electrical Stimulation and Voluntary Contractions at Different Force Levels: A NIRS Study.

Science.gov (United States)

Muthalib, Makii; Kerr, Graham; Nosaka, Kazunori; Perrey, Stephane

2016-06-13

Functional Muscle metabolic demand during contractions evoked by neuromuscular electrical stimulation (NMES) has been consistently documented to be greater than voluntary contractions (VOL) at the same force level (10-50% maximal voluntary contraction-MVC). However, we have shown using a near-infrared spectroscopy (NIRS) technique that local muscle metabolic demand is similar between NMES and VOL performed at MVC levels, thus controversy exists. This study therefore compared biceps brachii muscle metabolic demand (tissue oxygenation index-TOI and total hemoglobin volume-tHb) during a 10s isometric contraction of the elbow flexors between NMES (stimulation frequency of 30Hz and current level to evoke 30% MVC) and VOL at 30% MVC (VOL-30%MVC) and MVC (VOL-MVC) level in 8 healthy men (23-33-y). Greater changes in TOI and tHb induced by NMES than VOL-30%MVC confirm previous studies of a greater local metabolic demand for NMES than VOL at the same force level. The same TOI and tHb changes for NMES and VOL-MVC suggest that local muscle metabolic demand and intramuscular pressure were similar between conditions. In conclusion, these findings indicate that NMES induce a similar local muscle metabolic demand as that of maximal VOL.

Sample preparation method for scanning force microscopy

CERN Document Server

Jankov, I R; Szente, R N; Carreno, M N P; Swart, J W; Landers, R

2001-01-01

We present a method of sample preparation for studies of ion implantation on metal surfaces. The method, employing a mechanical mask, is specially adapted for samples analysed by Scanning Force Microscopy. It was successfully tested on polycrystalline copper substrates implanted with phosphorus ions at an acceleration voltage of 39 keV. The changes of the electrical properties of the surface were measured by Kelvin Probe Force Microscopy and the surface composition was analysed by Auger Electron Spectroscopy.

Classical theory of electric and magnetic fields

CERN Document Server

Good, Roland H

1971-01-01

Classical Theory of Electric and Magnetic Fields is a textbook on the principles of electricity and magnetism. This book discusses mathematical techniques, calculations, with examples of physical reasoning, that are generally applied in theoretical physics. This text reviews the classical theory of electric and magnetic fields, Maxwell's Equations, Lorentz Force, and Faraday's Law of Induction. The book also focuses on electrostatics and the general methods for solving electrostatic problems concerning images, inversion, complex variable, or separation of variables. The text also explains ma

Contributions to muscle force and EMG by combined neural excitation and electrical stimulation

Science.gov (United States)

Crago, Patrick E.; Makowski, Nathaniel S.; Cole, Natalie M.

2014-10-01

Objective. Stimulation of muscle for research or clinical interventions is often superimposed on ongoing physiological activity without a quantitative understanding of the impact of the stimulation on the net muscle activity and the physiological response. Experimental studies show that total force during stimulation is less than the sum of the isolated voluntary and stimulated forces, but the occlusion mechanism is not understood. Approach. We develop a model of efferent motor activity elicited by superimposing stimulation during a physiologically activated contraction. The model combines action potential interactions due to collision block, source resetting, and refractory periods with previously published models of physiological motor unit recruitment, rate modulation, force production, and EMG generation in human first dorsal interosseous muscle to investigate the mechanisms and effectiveness of stimulation on the net muscle force and EMG. Main results. Stimulation during a physiological contraction demonstrates partial occlusion of force and the neural component of the EMG, due to action potential interactions in motor units activated by both sources. Depending on neural and stimulation firing rates as well as on force-frequency properties, individual motor unit forces can be greater, smaller, or unchanged by the stimulation. In contrast, voluntary motor unit EMG potentials in simultaneously stimulated motor units show progressive occlusion with increasing stimulus rate. The simulations predict that occlusion would be decreased by a reverse stimulation recruitment order. Significance. The results are consistent with and provide a mechanistic interpretation of previously published experimental evidence of force occlusion. The models also predict two effects that have not been reported previously—voluntary EMG occlusion and the advantages of a proximal stimulation site. This study provides a basis for the rational design of both future experiments and clinical

Silk cocoon drying in forced convection type solar dryer

International Nuclear Information System (INIS)

Singh, Panna Lal

2011-01-01

The thin layer silk cocoon drying was studied in a forced convection type solar dryer. The drying chamber was provided with several trays on which the cocoons loaded in thin layer. The hot air generated in the solar air heater was forced into drying chamber to avoid the direct exposure of sunlight and UV radiation on cocoons. The drying air temperature varied from 50 to 75 o C. The cocoon was dried from the initial moisture content of about 60-12% (wb). The drying data was fitted to thin layer drying models. Drying behaviour of the silk cocoon was best fitted with the Wang and Singh drying model. Good agreement was obtained between predicted and experimental values. Quality of the cocoons dried in the solar dryer was at par with the cocoons dried in the conventional electrical oven dryer in term of the silk yield and strength of the silk. Saving of electrical energy was about 0.75 kWh/kg cocoons dried. Economic analysis indicated that the NPV of the solar dryer was higher and more stable (against escalation rate of electricity) as compare to the same for electrical oven dryer. Due to simplicity in design and construction and significant saving of operational electrical energy, solar cocoon dryer seems to be a viable option.

Magnetohydrodynamic flow in ducts with discontinuous electrical insulation

International Nuclear Information System (INIS)

Mistrangelo, C.; Bühler, L.

2015-01-01

Highlights: • Liquid metal MHD flows in ducts with flow channel inserts. • Study of the influence of local interruption of electrical insulation. • 3D numerical simulations. - Abstract: In liquid metal blankets the interaction of the moving breeder with the intense magnetic field that confines the fusion plasma results in significant modifications of the velocity distribution and increased pressure drop compared to hydrodynamic flows. Those changes are due to the occurrence of electromagnetic forces that slow down the core flow and which are balanced by large driving pressure heads. The resulting magnetohydrodynamic (MHD) pressure losses are proportional to the electric current density induced in the fluid and they can be reduced by electrically decoupling the wall from the liquid metal. For applications to dual coolant blankets it is foreseen to loosely insert electrically insulating liners into the ducts. In long channels the insulation could consist of a number of shorter inserts, which implies a possible local interruption of the insulation. Three dimensional numerical simulations have been performed to investigate MHD flows in electrically well-conducting channels with internal discontinuous insulating inserts. The local jump in the electric conductivity of the duct wall results in induced 3D electric currents and related electromagnetic forces yielding additional pressure losses and increased velocity in boundary layers parallel to the magnetic field.

The effects of electric forces on dust lifting: Preliminary studies with a numerical model

International Nuclear Information System (INIS)

Kok, J F; Renno, N O

2008-01-01

Atmospheric dust aerosols affect the Earth's climate by scattering and absorbing radiation and by modifying cloud properties. Recent experiments have indicated that electric fields produced in dusty phenomena such as dust storms and dust devils could enhance the emission of dust aerosols. However, the generation of electric fields in dusty phenomena is poorly understood. To address this problem, we present results from the first physically-based numerical model of electric fields in dust lifting. Our model calculates the motion and collisions of air-borne particles, as well as the charge transfer during these collisions. This allows us to simulate the formation of electric fields as a function of physical parameters, such as wind stress and soil properties. Preliminary model results show that electric fields can indeed enhance the lifting of soil particles. Moreover, they suggest that strong electric fields could trigger a positive feedback because increases in the concentration of charged particles strengthen the original electric field, which in turn lifts additional surface particles. We plan to further test and calibrate our model with experimental data.

Research on motor rotational speed measurement in regenerative braking system of electric vehicle

Science.gov (United States)

Pan, Chaofeng; Chen, Liao; Chen, Long; Jiang, Haobin; Li, Zhongxing; Wang, Shaohua

2016-01-01

Rotational speed signals acquisition and processing techniques are widely used in rotational machinery. In order to realized precise and real-time control of motor drive and regenerative braking process, rotational speed measurement techniques are needed in electric vehicles. Obtaining accurate motor rotational speed signal will contribute to the regenerative braking force control steadily and realized higher energy recovery rate. This paper aims to develop a method that provides instantaneous speed information in the form of motor rotation. It addresses principles of motor rotational speed measurement in the regenerative braking systems of electric vehicle firstly. The paper then presents ideal and actual Hall position sensor signals characteristics, the relation between the motor rotational speed and the Hall position sensor signals is revealed. Finally, Hall position sensor signals conditioning and processing circuit and program for motor rotational speed measurement have been carried out based on measurement error analysis.

Improvement and Neuroplasticity after Combined Rehabilitation to Forced Grasping

Directory of Open Access Journals (Sweden)

Michiko Arima

2017-01-01

Full Text Available The grasp reflex is a distressing symptom but the need to treat or suppress it has rarely been discussed in the literature. We report the case of a 17-year-old man who had suffered cerebral infarction of the right putamen and temporal lobe 10 years previously. Forced grasping of the hemiparetic left upper limb was improved after a unique combined treatment. Botulinum toxin type A (BTX-A was first injected into the left biceps, wrist flexor muscles, and finger flexor muscles. Forced grasping was reduced along with spasticity of the upper limb. In addition, repetitive facilitative exercise and object-related training were performed under low-amplitude continuous neuromuscular electrical stimulation. Since this 2-week treatment improved upper limb function, we compared brain activities, as measured by near-infrared spectroscopy during finger pinching, before and after the combined treatment. Brain activities in the ipsilesional sensorimotor cortex (SMC and medial frontal cortex (MFC during pinching under electrical stimulation after treatment were greater than those before. The results suggest that training under electrical stimulation after BTX-A treatment may modulate the activities of the ipsilesional SMC and MFC and lead to functional improvement of the affected upper limb with forced grasping.

Combined free and forced convection flow in a rotating channel with ...

African Journals Online (AJOL)

user

free and forced convection flow of a viscous incompressible electrically conducting fluid in a .... The boundary conditions (10) and (11), in dimensionless form, become ...... On hydromagnetic Flow and heat transfer in a rotating fluid past an infinite porous ... Electrically Conducting Fluid in Non-Rotating and Rotating Media”.

Improving the contact resistance at low force using gold coated carbon nanotube surfaces

Science.gov (United States)

McBride, J. W.; Yunus, E. M.; Spearing, S. M.

2010-04-01

Investigations to determine the electrical contact performance under repeated cycles at low force conditions for carbon-nanotube (CNT) coated surfaces were performed. The surfaces under investigation consisted of multi-walled CNT synthesized on a silicon substrate and coated with a gold film. These planar surfaces were mounted on the tip of a PZT actuator and contacted with a plated Au hemispherical probe. The dynamic applied force used was 1 mN. The contact resistance (Rc) of these surfaces was investigated with the applied force and with repeated loading cycles performed for stability testing. The surfaces were compared with a reference Au-Au contact under the same experimental conditions. This initial study shows the potential for the application of gold coated CNT surfaces as an interface in low force electrical contact applications.

Electrical stimulation superimposed onto voluntary muscular contraction.

Science.gov (United States)

Paillard, Thierry; Noé, Frédéric; Passelergue, Philippe; Dupui, Philippe

2005-01-01

Electrical stimulation (ES) reverses the order of recruitment of motor units (MU) observed with voluntary muscular contraction (VOL) since under ES, large MU are recruited before small MU. The superimposition of ES onto VOL (superimposed technique: application of an electrical stimulus during a voluntary muscle action) can theoretically activate more motor units than VOL performed alone, which can engender an increase of the contraction force. Two superimposed techniques can be used: (i) the twitch interpolation technique (ITT), which consists of interjecting an electrical stimulus onto the muscle nerve; and (ii) the percutaneous superimposed electrical stimulation technique (PST), where the stimulation is applied to the muscle belly. These two superimposed techniques can be used to evaluate the ability to fully activate a muscle. They can thus be employed to distinguish the central or peripheral nature of fatigue after exhausting exercise. In general, whatever the technique employed, the superimposition of ES onto volitional exercise does not recruit more MU than VOL, except with eccentric actions. Nevertheless, the neuromuscular response associated with the use of the superimposed technique (ITT and PST) depends on the parameter of the superimposed current. The sex and the training level of the subjects can also modify the physiological impact of the superimposed technique. Although the motor control differs drastically between training with ES and VOL, the integration of the superimposed technique in training programmes with healthy subjects does not reveal significant benefits compared with programmes performed only with voluntary exercises. Nevertheless, in a therapeutic context, training programmes using ES superimposition compensate volume and muscle strength deficit with more efficiency than programmes using VOL or ES separately.

Electricity - a great asset for Canada

International Nuclear Information System (INIS)

Chretien, Jean.

1983-06-01

Canada has a great national asset in its ability to generate electricity economically from its abundant hydro, coal, and uranium resources. Its nuclear industry has an excellent product. Despite lack of orders for now, the CANDU will be a competitive force when the reactor market recovers. Canada has a proven record of reliability for electricity trade with the United States. There appear to be some opportunities for plants in Canada dedicated to the export of electric power. The federal government is prepared to work closely with the provinces to develop projects which will be attractive to customers in the United States

Clinical significance of isometric bite force versus electrical activity in temporal and masseter muscles

DEFF Research Database (Denmark)

Bakke, Merete; Michler, L; Han, K

1989-01-01

significant with respect to unilateral, but not to bilateral force measurements. Only in the masseter muscle was strength of dynamic contractions during chewing significantly correlated to bite force. With the present method it was demonstrated that unilateral bite force is a simple clinical indicator...

Determining market boundaries in the electricity sector

International Nuclear Information System (INIS)

Godde, Anne

2013-01-01

The purpose of the present study was to develop a method of determining market boundaries in preparation of identifying all the competitive forces which a company in the electricity sector must address and deciding on this basis whether it has a dominant position in the market. The study focused in particular on current developments in the German electricity sector, this being the only way to permit a demarcation that accurately reflects the true economic situation. First the question was addressed whether a determination of market boundaries is at all necessary for performing a competitive analysis and in what specific constellations they could play a role. Giving due consideration to the special features of the electricity sector the most preferable market demarcation methods were applied to individual areas of the electricity sector that are of competitive relevance. Efforts were directed at arriving at market boundaries most conducive to the goal of identifying those competitive forces which a company in the electricity sector must address. For this purpose a critical assessment was undertaken of established market demarcation practices in Europe and Germany in order to determine whether ''classical'' market demarcation methods could be applied or whether modifications were needed on account of special features of market structure. The author also describes and discusses alternatives to the established market demarcation methods. She also elucidates methods of determining the boundaries of markets that have emerged as a result of recent developments in the electricity sector, for example through the growth of electricity production from renewable resources, or which are still in the process of formation.

On possible beneficial ponderomotive force effects on fast wave coupling in tokamaks

International Nuclear Information System (INIS)

Petrzilka, V.

1994-02-01

Ponderomotive forces at fast wave launching lead in the vicinity of the launching structure in tokamaks at lower hybrid frequencies typically to a boundary plasma density increase. This results in a decrease of the reflection coefficient, and in cases of detached plasmas, to an appearance of a local electric field maximum at a distance of several centimeters from the launching grill structure; this electric field maximum is connected to the reversal of the plasma density gradient near the grill mouth because of ponderomotive force effects. (author) 3 figs., 20 refs

On the pulsating electric wind of a Single Dielectric Barrier Discharge (SDBD) plasma actuator

Science.gov (United States)

Vernet, Julie; Örlü, Ramis; Alfredsson, P. Henrik

2014-11-01

An experimental study is conducted on the electric wind produced by a Single Dielectric Barrier Discharge (SDBD) plasma actuator placed at the top of a half cylinder. Laser Doppler Velocimetry (LDV) measurements were performed and results show that increasing the driving voltage (6-16 kV peak-to-peak) and frequency (0.5-2 kHz) of the actuator increases the induced jet velocity (up to 4 m/s) and thus the momentum added by the actuator. The focus of the present study is on the phase-resolved behavior of the electric wind, in particular, its two strokes. Phase-averaged LDV data reveals that while the velocity during both strokes remains positive, there is nearly a factor of two in amplitude. The difference of behavior between the two strokes and its downstream and wall-normal evolution are mapped for various driving voltages. Results indicate that this difference is restricted to the vicinity of the actuator, thereby justifying the assumption of a steady force in simulations to model the induced force. The study is part of a larger investigation aiming at separation control on the A-pillar of a truck cabin. The support of the Swedish Energy Agency and SCANIA CV of the project Flow Research on Active and Novel Control Efficiency (FRANCE) is greatly acknowledged.

INCREASED RELIABILITY OF ELECTRIC BLASTING

OpenAIRE

Kashuba, Oleh Ivanovych; Skliarov, L I; Skliarov, A L

2017-01-01

The problems of improving reliability of an electric blasting method using electric detonators with nichrome filament bridges. It was revealed that in the calculation of the total resistance of the explosive network it is necessary to increase to 24% of the nominal value

Nanocrystalline SnO2 thin films: Structural, morphological, electrical transport and optical studies

International Nuclear Information System (INIS)

Sakhare, R.D.; Khuspe, G.D.; Navale, S.T.; Mulik, R.N.; Chougule, M.A.; Pawar, R.C.; Lee, C.S.; Sen, Shashwati; Patil, V.B.

2013-01-01

Highlights: ► Novel chemical route of synthesis of SnO 2 films. ► Physical properties SnO 2 are influenced by process temperature. ► The room temperature electrical conductivity of SnO 2 is of 10 −7 –10 −5 (Ω cm) −1 . ► SnO 2 exhibit high absorption coefficient (10 4 cm −1 ). -- Abstract: Sol–gel spin coating method has been successfully employed for preparation of nanocrystalline tin oxide (SnO 2 ) thin films. The effect of processing temperature on the structure, morphology, electrical conductivity, thermoelectric power and band gap was studied using X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, selected area electron diffraction pattern, atomic force microscopy, two probe technique and UV–visible spectroscopy. X-ray diffraction (XRD) analysis showed that SnO 2 films are crystallized in the tetragonal phase and present a random orientation. Field emission scanning electron microscopy (FESEM) analysis revealed that surface morphology of the tin oxide film consists nanocrystalline grains with uniform coverage of the substrate surface. Transmission electron microscopy (TEM) of SnO 2 film showed nanocrystals having diameter ranging from 5 to 10 nm. Selected area electron diffraction (SAED) pattern confirms tetragonal phase evolution of SnO 2 . Atomic force microscopy (AFM) analysis showed surface morphology of SnO 2 film is smooth. The dc electrical conductivity showed the semiconducting nature with room temperature electrical conductivity increased from 10 −7 to 10 −5 (Ω cm) −1 as processing temperature increased from 400 to 700 °C. Thermo power measurement confirms n-type conduction. The band gap energy of SnO 2 film decreased from 3.88 to 3.60 eV as processing temperature increased from 400 to 700 °C

The Electromotive Force in Different Reference Frames

Science.gov (United States)

Adler, Charles L.

2018-05-01

The electromotive force (EMF) is the work per unit charge around a wire loop caused by a time-varying magnetic flux threading the loop. It is due to a force moving the charges around the loop. This is true whether the change in flux is due to the wire loop being stationary and the field changing in time, or the loop moving through a spatially varying field. In the first case, we say that the time-varying magnetic field induces an electric field that provides the force; in the second, we say that the force is due to the magnetic field acting on the charges in the moving loop. The theory of relativity states that both viewpoints must be equivalent, but it is sometimes difficult to harmonize them.

Comparison of Theodorsen's Unsteady Aerodynamic Forces with Doublet Lattice Generalized Aerodynamic Forces

Science.gov (United States)

Perry, Boyd, III

2017-01-01

This paper identifies the unsteady aerodynamic forces and moments for a typical section contained in the NACA Report No. 496, "General Theory of Aerodynamic Instability and the Mechanism of Flutter," by Theodore Theodorsen. These quantities are named Theodorsen's aerodynamic forces (TAFs). The TAFs are compared to the generalized aerodynamic forces (GAFs) for a very high aspect ratio wing (AR = 20) at zero Mach number computed by the doublet lattice method. Agreement between TAFs and GAFs is very-good-to-excellent. The paper also reveals that simple proportionality relationships that are known to exist between the real parts of some GAFs and the imaginary parts of others also hold for the real and imaginary parts of the corresponding TAFs.

Nanoscale electrical property studies of individual GeSi quantum rings by conductive scanning probe microscopy.

Science.gov (United States)

Lv, Yi; Cui, Jian; Jiang, Zuimin M; Yang, Xinju

2012-11-29

The nanoscale electrical properties of individual self-assembled GeSi quantum rings (QRs) were studied by scanning probe microscopy-based techniques. The surface potential distributions of individual GeSi QRs are obtained by scanning Kelvin microscopy (SKM). Ring-shaped work function distributions are observed, presenting that the QRs' rim has a larger work function than the QRs' central hole. By combining the SKM results with those obtained by conductive atomic force microscopy and scanning capacitance microscopy, the correlations between the surface potential, conductance, and carrier density distributions are revealed, and a possible interpretation for the QRs' conductance distributions is suggested.

Optical and electrical characterizations of nanoparticle Cu2S thin films

International Nuclear Information System (INIS)

Saadeldin, M.; Sawaby, K.; Soliman, H. S.; Ali, H. A. M.

2014-01-01

Copper sulfide thin films are deposited onto different substrates at room temperature using the thermal evaporation technique. X-ray diffraction spectra show that the film has an orthorhombicchalcocite (γ-Cu 2 S) phase. The atomic force microscopy images indicate that the film exhibits nanoparticles with an average size of nearly 44 nm. Specrtophotometric measurements for the transmittance and reflectance are carried out at normal incidence in a spectral wavelength range of 450 nm–2500 nm. The refractive index, n, as well as the absorption index, k is calculated. Some dispersion parameters are determined. The analyses of ε 1 and ε 2 reveal several absorption peaks. The analysis of the spectral behavior of the absorption coefficient, α, in the absorption region reveals direct and indirect allowed transitions. The dark electrical resistivity is studied as a function of film thickness and temperature. Tellier's model is adopted for determining the mean free path and bulk resistance. (condensed matter: structural, mechanical, and thermal properties)

Mechanic-electrical transformations in the Kelvin method

Energy Technology Data Exchange (ETDEWEB)

Zharkikh, Yu. S., E-mail: yurzhar@gmail.com [Faculty of Radio Physics, Electronics and Computer Systems, Taras Shevchenko National University of Kyiv, 4G, Ave. Academician Glushkov, 03127, Kyiv (Ukraine); Lysochenko, S.V., E-mail: lys@univ.kiev.ua [Institute of High Technologies, Taras Shevchenko National University of Kyiv, 4G, Ave. Academician Glushkov, 03127, Kyiv (Ukraine)

2017-04-01

Highlights: • Used in Kelvin method dynamic capacitor is a mechanic-electrical transformer. • The oscillations of its plate are source of extraneous forces which cause the appearance of an electric current. • The signal is caused not by the contact potential difference, but by oscillation in the screening conditions of charge in the dynamic capacitor gap. • Combining the Kelvin method with electron emission methods to determine the work function may lead to incorrectness. - Abstract: To explain the initiation mechanism of alternating current in an electric circuit containing the dynamic capacitor a model of mechanic- electrical transformation is suggested to use. In such a model, electric charges disposed between the capacitor plates serve as a cause of measured signal in contrast to the contact potential difference, which is considered as the main base in the Kelvin’s model. If one of the plates moves periodically, then the conditions of the charges screening are changed and thereby the capacitor recharging current is arise. The measuring is based on compensation of the recharging current by current, which generated by a source of electromotive force (EMF). The compensation voltage depends on both the distribution of ions or dipoles over the studied surface and the charges creating the surface potential barrier. This voltage is independent on the bulk electro-physical characteristics of a solid.

Revealing by secondary electronic emission of internal electric fields in the yttriated zirconia, irradiated by electrons of 1 MeV

International Nuclear Information System (INIS)

Blaise, G.; Paris-11 Univ., 91 - Orsay

2007-01-01

The defects due to irradiation in a dielectric material present an activity which can generate macroscopic internal electric fields. A method of investigation of these fields, based on the measure of the Secondary Electronic Emission coefficient, has been developed on a scanning electric microscope. This ones contains two low noise detectors which respectively measure the influence current I IC produced by the charges trapping in the material and the current I SB due to secondary and backscattered electrons which come from the sample. The Secondary Emission coefficient is given by σ=I SB /(I SB +I IC ). The charges trapping during an electrons injection leads to a variation of σ for its intrinsic value σ 0 relative to the uncharged material, until the stationary value σ st =1 corresponding to the auto-regulated condition. This variation is due to the development of an internal electric field produced by the accumulation of the charges trapped during injection. In comparing the evolutions of σ of a fresh yttriated zirconia and of an yttriated zirconia irradiated by electrons of 1 MeV with a dose rate of 10 18 e/cm 2 , it has been revealed that an internal field (due to irradiation) of about 0.5*10 6 V/m exists at a depth of the micron order. This field, directed towards the outside of the material surface, is attributed to the F + defects and to the T centers produced by the impact of the electrons of 1 MeV. In carrying out annealings until 1000 K, a progressive disappearance of this field is observed in the temperature range of 400-600 K, directly due to the F + defects and T centers recovery, as it has been observed by ESR. An internal field three times weaker than the preceding ones has been revealed at a few nm under the surface. Its disappearance from a temperature of 1000 K suggests that it is due to the redistribution of the chemical species into the surface, during the irradiation with electrons of 1 MeV. (O.M.)

Distributed control in the electricity infrastructure

International Nuclear Information System (INIS)

Kok, J.K.; Warmer, C.; Kamphuis, I.G.; Mellstrand, P.; Gustavsson, R.

2006-01-01

Different driving forces push the electricity production towards decentralization. As a result, the current electricity infrastructure is expected to evolve into a network of networks, in which all system parts communicate with each other and influence each other. Multiagent systems and electronic markets form an appropriate technology needed for control and coordination tasks in the future electricity network. We present the PowerMatcher, a market-based control concept for supply demand matching (SDM) in electricity networks. In a simulation study we show the ability of this approach to raise the simultaneousness of electricity production and consumption within (local) control clusters. This control concept can be applied in different business cases like reduction of imbalance costs in commercial portfolios or virtual power plant operation of distributed generators. Two PowerMatcher-based field test configurations are described, one currently in operation, one currently under construction

Casimir-Polder forces on atoms in the presence of magnetoelectronic bodies

International Nuclear Information System (INIS)

Buhmann, S.Y.

2007-01-01

In this work, the CP force between a single neutral atom or molecule and neutral magnetoelectric bodies is studied. The focus lies on the pure vacuum CP force, i.e., the electromagnetic field is in general understood to be in its ground state. Furthermore, we assume that the atom-body separation is sufficiently large to ensure that the atom is adequately characterised as an electric dipole, while the body can be described by its macroscopic magnetoelectric properties; and that repulsive exchange forces due to the overlap between the electronic wave functions of the atom and the bodies can be neglected. Interactions due to non-vanishing net charges, permanent electric dipole moments, magnetisability, quadrupole (or higher multipole) polarisabilities of the atom and those resulting from non-local or anisotropic magnetoelectric properties of the bodies are ignored. (orig.)

Casimir-Polder forces on atoms in the presence of magnetoelectronic bodies

Energy Technology Data Exchange (ETDEWEB)

Buhmann, S Y

2007-07-05

In this work, the CP force between a single neutral atom or molecule and neutral magnetoelectric bodies is studied. The focus lies on the pure vacuum CP force, i.e., the electromagnetic field is in general understood to be in its ground state. Furthermore, we assume that the atom-body separation is sufficiently large to ensure that the atom is adequately characterised as an electric dipole, while the body can be described by its macroscopic magnetoelectric properties; and that repulsive exchange forces due to the overlap between the electronic wave functions of the atom and the bodies can be neglected. Interactions due to non-vanishing net charges, permanent electric dipole moments, magnetisability, quadrupole (or higher multipole) polarisabilities of the atom and those resulting from non-local or anisotropic magnetoelectric properties of the bodies are ignored. (orig.)

Alternative current source based Schottky contact with additional electric field

Science.gov (United States)

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

2017-07-01

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

Effects of water vapor on flue gas conditioning in the electric fields with corona discharge.

Science.gov (United States)

Liqiang, Qi; Yajuan, Zhang

2013-07-15

Sulfur dioxide (SO2) removal via pulsed discharge nonthermal plasma in the absence of ammonia was investigated to determine how electrostatic precipitators (ESPs) can effectively collect particulate matter less than 2.5μm in diameter from flue gas. SO2 removal increased as water vapor concentration increased. In a wet-type plasma reactor, directing a gas-phase discharge plasma toward the water film surface significantly enhanced the liquid-phase oxidation of HSO3(-) to SO4(2-). Comparisons of various absorbents revealed that the hydroxyl radical is a key factor in plasma-induced liquid-phase reactions. The resistivity, size distribution, and cohesive force of fly ash at different water vapor contents were measured using a Bahco centrifuge, which is a dust electrical resistivity test instrument, as well as a cohesive force test apparatus developed by the researchers. When water vapor content increased by 5%, fly ash resistivity in flue gas decreased by approximately two orders of magnitude, adhesive force and size increased, and specific surface area decreased. Therefore, ESP efficiency increased. Copyright © 2013 Elsevier B.V. All rights reserved.

Electrical property heterogeneity at transparent conductive oxide/organic semiconductor interfaces: mapping contact ohmicity using conducting-tip atomic force microscopy.

Science.gov (United States)

MacDonald, Gordon A; Veneman, P Alexander; Placencia, Diogenes; Armstrong, Neal R

2012-11-27

We demonstrate mapping of electrical properties of heterojunctions of a molecular semiconductor (copper phthalocyanine, CuPc) and a transparent conducting oxide (indium-tin oxide, ITO), on 20-500 nm length scales, using a conductive-probe atomic force microscopy technique, scanning current spectroscopy (SCS). SCS maps are generated for CuPc/ITO heterojunctions as a function of ITO activation procedures and modification with variable chain length alkyl-phosphonic acids (PAs). We correlate differences in small length scale electrical properties with the performance of organic photovoltaic cells (OPVs) based on CuPc/C(60) heterojunctions, built on these same ITO substrates. SCS maps the "ohmicity" of ITO/CuPc heterojunctions, creating arrays of spatially resolved current-voltage (J-V) curves. Each J-V curve is fit with modified Mott-Gurney expressions, mapping a fitted exponent (γ), where deviations from γ = 2.0 suggest nonohmic behavior. ITO/CuPc/C(60)/BCP/Al OPVs built on nonactivated ITO show mainly nonohmic SCS maps and dark J-V curves with increased series resistance (R(S)), lowered fill-factors (FF), and diminished device performance, especially near the open-circuit voltage. Nearly optimal behavior is seen for OPVs built on oxygen-plasma-treated ITO contacts, which showed SCS maps comparable to heterojunctions of CuPc on clean Au. For ITO electrodes modified with PAs there is a strong correlation between PA chain length and the degree of ohmicity and uniformity of electrical response in ITO/CuPc heterojunctions. ITO electrodes modified with 6-8 carbon alkyl-PAs show uniform and nearly ohmic SCS maps, coupled with acceptable CuPc/C(60)OPV performance. ITO modified with C14 and C18 alkyl-PAs shows dramatic decreases in FF, increases in R(S), and greatly enhanced recombination losses.

Dielectric Analysis for Torque of a Solute Ion Coulomb Force Monopole Motor

Science.gov (United States)

Fresco, Anthony N.

ASME Technical Paper ES2010-90396 "Solute Ion Coulomb Force Monopole Motor and Solute Ion Linear Alignment Propulsion" by the author describes a motor that is based on an arrangement of solute ion electric field monopoles.[1] That is, through a process called capacitive deionization, sodium and chlorine ions in salt water are captured and confined by an electrically conductive material to form electric field monopoles. At least four of the like charged monopoles (all negative or all positive) can be arranged on a disc. At least one stationary monopole of the same charge is placed adjacent to the disc and positioned so that a repulsive electric field is formed between the stationary monopole and at least one of the monopoles positioned on the disc so that the disc is then forced to rotate a shaft at the center of the disc. This paper analyzes the behavior of the dielectric materials forming part of the monopoles to show that the net torque on the motor is greater than zero and also illustrates a novel effect of polarization of a dielectric material positioned between two like-charged monopoles as occurs in the configuration of the monopole motor and a deficiency in the conventional closed path analysis for work performed during movement of electric charges that emit electrostatic fields by failing to consider the effects of dielectric materials in shielding the electrostatic fields. The monopole motor connected to an to electrical generator can provide continuous on-board electrical power to electrical loads for local and deep space applications including power to electrode assemblies designed for linear alignment of like-charged solute ions as a means of propulsion and particle acceleration as described in the ES2010-90396 paper. Details of the monopole motor and the propulsion are available in WO 2008/024927 A2 (and US2010/0199632 A1) "Solute Ion Coulomb Force Acceleration and Electric Field Monopole Passive Voltage Source" by the author Ref.[2].

Casimir force in the presence of a medium

International Nuclear Information System (INIS)

Kheirandish, Fardin; Soltani, Morteza; Sarabadani, Jalal

2010-01-01

We investigate the Casimir effect in the presence of a medium by quantizing the electromagnetic field in the presence of a magnetodielectric medium using the path-integral technique. For a given medium with definite electric and magnetic susceptibilities, explicit expressions for the Casimir force are obtained. The Lifshitz formula is recovered and in the absence of a medium the results tend to the original Casimir force between two conducting parallel plates immersed in the quantum electromagnetic vacuum.

Grade 10 Thai students' scientific argumentation in learning about electric field through science, technology, and society (STS) approach

Science.gov (United States)

Chitnork, Amporn; Yuenyong, Chokchai

2018-01-01

The research aimed to enhance Grade 10 Thai students' scientific argumentation in learning about electric field through science, technology, and society (STS) approach. The participants included 45 Grade 10 students who were studying in a school in Nongsonghong, Khon Kaen, Thailand. Methodology regarded interpretive paradigm. The intervention was the force unit which was provided based on Yuenyong (2006) STS approach. Students learned about the STS electric field unit for 4 weeks. The students' scientific argumentation was interpreted based on Toulmin's argument pattern or TAP. The TAP provided six components of argumentation including data, claim, warrants, qualifiers, rebuttals and backing. Tools of interpretation included students' activity sheets, conversation, journal writing, classroom observation and interview. The findings revealed that students held the different pattern of argumentation. Then, they change pattern of argumentation close to the TAP. It indicates that the intervention of STS electric field unit enhance students to develop scientific argumentation. This finding may has implication of further enhancing scientific argumentation in Thailand.

Analysis of thermal coal pricing and the coal price distortion in China from the perspective of market forces

International Nuclear Information System (INIS)

Cui, Herui; Wei, Pengbang

2017-01-01

The price of thermal coal has always been the focus of the debate between coal mining industry and electric power industry. The thermal coal price is always lower than other same quality coal, and this phenomenon of thermal coal price distortion has been existing in China for a long time. The distortion coal price can not reflect the external cost and the resource scarcity of coal, which could result in environment deteriorating and inefficient resource allocation. This paper studied the phenomenon of thermal coal price distortion through economic theoretical modeling and empirical cointegration analysis from the perspective of market forces. The results show that thermal coal price is determined by electricity price, the prediction elasticity of a electricity enterprise, price elasticity of demand of electricity, the input prediction elasticity of a electricity enterprise and the price elasticity of supply of thermal coal. The main reason of coal price distortion is the unbalance market force of coal industry and thermal coal generation industry. The distortion rate of coal price is positively related to the market force of electric power industry and negatively related to the industrial concentration of coal industry. - Highlights: • This paper studied thermal coal pricing and the coal price distortion in China. • The main reason of coal price distortion is the unbalance market force. • Thermal coal price is also influenced by electricity price and price elasticity of demand of electricity. • The distortion rate of coal price is negatively related to the industrial concentration of coal industry.

A Sinusoidal Applied Electric Potential can Induce a Long-Range, Steady Electrophoretic Force

Science.gov (United States)

Amrei, Seyyed Hashemi; Ristenpart, William D.; Miller, Greg R.

2017-11-01

We use the standard electrokinetic model to numerically investigate the electric field in aqueous solutions between parallel electrodes under AC polarization. In contrast to prior work, we invoke no simplifying assumptions regarding the applied voltage, frequency, or mismatch in ionic mobilities. We find that the nonlinear electromigration terms significantly contribute to the overall shape of the electric potential vs. time, which at sufficiently high applied potentials develops multi-modal peaks. More surprisingly, we find that electrolytes with non-equal mobilities yield an electric field with non-zero time average at large distances from the electrodes. Our calculations indicate this long-range electric field suffices to levitate colloidal particles many microns away from the electrode against the gravitational field, in accord with experimental observations of such behavior (Woehl et al., PRX, 2015). Moreover, the results indicate that particles will aggregate laterally near electrodes in some electrolytes but separate in others, helping explain a longstanding but not well understood phenomenon.

Present state of electric power business in United States and Europe

International Nuclear Information System (INIS)

Onishi, Kenichi

2011-01-01

This article reported present state of nuclear power and electric power business in United States and Europe after Fukushima Daiichi Accident. As for the trend of demand and supply of electric power and policy, the accident forced Germany possibly to proceed with phase-out of nuclear power, but France and United States to sustain nuclear power with no great change of energy policy at this moment. As for the trend of electric power market, there was not state in United States with liberalized retail market of electric power after rolling blackouts occurred in California State in the early 2000s. In Germany proceeding with renewable energy introduction, renewable electricity fed into the grid was paid for by the network operators at fixed tariffs and the costs passed on to electricity consumers were increasing. Renewable Portfolio Standards (RPS) in United States forced the state to introduction of renewable energy to some ratio, and Feed-in Tariff (FIT) introduced in EU in 1990s lead to introduction of a large amount of renewable electricity targeted in 2020. Huge amount of wind power introduction brought about several problems to solve such that excess electric power above domestic demand had bad effects on grids in neighboring region. Enforcement of power transmission lines was also needed with increase of maximum electric power as well as introduction of a large amount of renewable electricity. (T. Tanaka)

Development of a Carbon Nanotube-Based Touchscreen Capable of Multi-Touch and Multi-Force Sensing

OpenAIRE

Kim, Wonhyo; Oh, Haekwan; Kwak, Yeonhwa; Park, Kwangbum; Ju, Byeong-Kwon; Kim, Kunnyun

2015-01-01

A force sensing touchscreen, which detects touch point and touch force simultaneously by sensing a change in electric capacitance, was designed and fabricated. It was made with single-walled carbon nanotubes (SWCNTs) which have better mechanical and chemical characteristics than the indium-tin-oxide transparent electrodes used in most contemporary touchscreen devices. The SWCNTs, with a transmittance of about 85% and electric conductivity of 400 Ω per square; were coated and patterned on glas...

Cancellation of the centrifugal space-charge force

International Nuclear Information System (INIS)

Lee, E.P.

1990-01-01

The transverse dynamics of high-energy electrons confined in curved geometry are examined, including the effects of space-charge-induced fields. Attention is restricted to the centrifugal-space-charge force, which is the result of noncancellation of beam-induced transverse electric and magnetic fields in the curved geometry. This force is shown to be nearly cancelled in the evaluation of the horizontal tune and chromaticity by another, often overlooked term in the equation of motion. The additional term is the consequence of oscillations of the kinetic energy, which accompany betatron oscillations in the beam-induced electric potential. In curved geometry this term is of first order in the amplitude of the radial oscillation. A highly simplified system model is employed so that physical effects appear in as clear a form as possible. We assume azimuthal and median plane symmetry, static fields, and ultrarelativistic particle velocity (1/γ 2 ->0). (author) 9 refs

Radiation resistant electrical bushing for high pressures and temperatures

Energy Technology Data Exchange (ETDEWEB)

Zajic, V; Banyr, J

1980-11-15

The bushing described is characterized by a hollow with a joining member provided inside of at least one of the bushing's electrically conductive core soldered or embedded into a bore in the insulator. Thus, the concentration is limited of the material of the electrically conductive core in the area of the soldered or embedded joint of the support of the electrically conductive core and the insulator, and the resulting force effect is reduced of the difference in thermal dilatations of the materials of the electrically conductive core and the insulator.

Radiation resistant electrical bushing for high pressures and temperatures

International Nuclear Information System (INIS)

Zajic, V.; Banyr, J.

1980-01-01

The bushing described is characterized by a hollow with a joining member provided inside of at least one of the bushing's electrically conductive core soldered or embedded into a bore in the insulator. Thus, the concentration is limited of the material of the electrically conductive core in the area of the soldered or embedded joint of the support of the electrically conductive core and the insulator, and the resulting force effect is reduced of the difference in thermal dilatations of the materials of the electrically conductive core and the insulator. (J.B.)

Development of a quartz tuning-fork-based force sensor for measurements in the tens of nanoNewton force range during nanomanipulation experiments

Energy Technology Data Exchange (ETDEWEB)

Oiko, V. T. A., E-mail: oiko@ifi.unicamp.br; Rodrigues, V.; Ugarte, D. [Instituto de Física “Gleb Wataghin,” Univ. Estadual de Campinas (UNICAMP), Campinas 13083-859 (Brazil); Martins, B. V. C. [Department of Physics, University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Silva, P. C. [Laboratório Nacional de Nanotecnologia, CNPEM, Campinas 13083-970 (Brazil)

2014-03-15

Understanding the mechanical properties of nanoscale systems requires new experimental and theoretical tools. In particular, force sensors compatible with nanomechanical testing experiments and with sensitivity in the nN range are required. Here, we report the development and testing of a tuning-fork-based force sensor for in situ nanomanipulation experiments inside a scanning electron microscope. The sensor uses a very simple design for the electronics and it allows the direct and quantitative force measurement in the 1–100 nN force range. The sensor response is initially calibrated against a nN range force standard, as, for example, a calibrated Atomic Force Microscopy cantilever; subsequently, applied force values can be directly derived using only the electric signals generated by the tuning fork. Using a homemade nanomanipulator, the quantitative force sensor has been used to analyze the mechanical deformation of multi-walled carbon nanotube bundles, where we analyzed forces in the 5–40 nN range, measured with an error bar of a few nN.

Characterization of structural and electrical properties of ZnO tetrapods

Science.gov (United States)

Gu, Yu-Dong; Mai, Wen-Jie; Jiang, Peng

2011-12-01

ZnO tetrapods were synthesized by a typical thermal vapor-solid deposition method in a horizontal tube furnace. Structural characterization was carried out by transmission electron microscopy (TEM) and select-area electron diffraction (SAED), which shows the presence of zinc blende nucleus in the center of tetrapods while the four branches taking hexagonal wurtzite structure. The electrical transport property of ZnO tetrapods was investigated through an in-situ nanoprobe system. The three branches of a tetrapod serve as source, drain, and "gate", respectively; while the fourth branch pointing upward works as the force trigger by vertically applying external force downward. The conductivity of each branch of ZnO-tetrapods increases 3-4 times under pressure. In such situation, the electrical current through the branches of ZnO tetrapods can be tuned by external force, and therefore a simple force sensor based on ZnO tetrapods has been demonstrated for the first time.

Magnus force effect in optical manipulation

International Nuclear Information System (INIS)

Cipparrone, Gabriella; Pagliusi, Pasquale; Hernandez, Raul Josue; Provenzano, Clementina

2011-01-01

The effect of the Magnus force in optical micromanipulation has been observed. An ad hoc experiment has been designed based on a one-dimensional optical trap that carries angular momentum. The observed particle dynamics reveals the occurrence of this hydrodynamic force, which is neglected in the common approach. Its measured value is larger than the one predicted by the existing theoretical models for micrometric particles and low Reynolds number, showing that the Magnus force can contribute to unconventional optohydrodynamic trapping and manipulation.

A programmable DNA origami nanospring that reveals force-induced adjacent binding of myosin VI heads.

Science.gov (United States)

Iwaki, M; Wickham, S F; Ikezaki, K; Yanagida, T; Shih, W M

2016-12-12

Mechanosensitive biological nanomachines such as motor proteins and ion channels regulate diverse cellular behaviour. Combined optical trapping with single-molecule fluorescence imaging provides a powerful methodology to clearly characterize the mechanoresponse, structural dynamics and stability of such nanomachines. However, this system requires complicated experimental geometry, preparation and optics, and is limited by low data-acquisition efficiency. Here we develop a programmable DNA origami nanospring that overcomes these issues. We apply our nanospring to human myosin VI, a mechanosensory motor protein, and demonstrate nanometre-precision single-molecule fluorescence imaging of the individual motor domains (heads) under force. We observe force-induced transitions of myosin VI heads from non-adjacent to adjacent binding, which correspond to adapted roles for low-load and high-load transport, respectively. Our technique extends single-molecule studies under force and clarifies the effect of force on biological processes.

The electrical double layer on gold probed by electrokinetic and surface force measurements

NARCIS (Netherlands)

Giesbers, M.; Kleijn, J.M.; Cohen Stuart, M.A.

2002-01-01

Gold surfaces, obtained by vacuum deposition of 15-nm gold films on glass and silica wafers, were studied in aqueous solutions by streaming potential measurements and colloidal-probe AFM force measurements. In the force measurements both a bare and a gold-coated silica particle (6 m in diameter)

ELECTRIC AND MAGNETIC FIELDS ELECTRIC AND GASOLINE-POWERED VEHICLES.

Science.gov (United States)

Tell, Richard A; Kavet, Robert

2016-12-01

Measurements were conducted to investigate electric and magnetic fields (EMFs) from 120 Hz to 10 kHz and 1.2 to 100 kHz in 9 electric or hybrid vehicles and 4 gasoline vehicles, all while being driven. The range of fields in the electric vehicles enclosed the range observed in the gasoline vehicles. Mean magnetic fields ranged from nominally 0.6 to 3.5 µT for electric/hybrids depending on the measurement band compared with nominally 0.4 to 0.6 µT for gasoline vehicles. Mean values of electric fields ranged from nominally 2 to 3 V m -1 for electric/hybrid vehicles depending on the band, compared with 0.9 to 3 V m -1 for gasoline vehicles. In all cases, the fields were well within published exposure limits for the general population. The measurements were performed with Narda model EHP-50C/EHP-50D EMF analysers that revealed the presence of spurious signals in the EHP-50C unit, which were resolved with the EHP-50D model. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels

International Nuclear Information System (INIS)

Jeggle, Pia; Smith, Ewan St. J.; Stewart, Andrew P.; Haerteis, Silke; Korbmacher, Christoph; Edwardson, J. Michael

2015-01-01

ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers. - Highlights: • There is evidence for a close association between ASIC and ENaC. • We used AFM to test whether ASIC1a and ENaC subunits form cross-clade ion channels. • Isolated proteins were incubated with subunit-specific antibodies and Fab fragments. • Some proteins were doubly decorated at ∼120° by an antibody and a Fab fragment. • Our results indicate the formation of ASIC1a/ENaC heterotrimers

Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels

Energy Technology Data Exchange (ETDEWEB)

Jeggle, Pia; Smith, Ewan St. J.; Stewart, Andrew P. [Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD (United Kingdom); Haerteis, Silke; Korbmacher, Christoph [Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 6, 91054 Erlangen (Germany); Edwardson, J. Michael, E-mail: jme1000@cam.ac.uk [Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD (United Kingdom)

2015-08-14

ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers. - Highlights: • There is evidence for a close association between ASIC and ENaC. • We used AFM to test whether ASIC1a and ENaC subunits form cross-clade ion channels. • Isolated proteins were incubated with subunit-specific antibodies and Fab fragments. • Some proteins were doubly decorated at ∼120° by an antibody and a Fab fragment. • Our results indicate the formation of ASIC1a/ENaC heterotrimers.

Microscopic derivation of the force on a dielectric fluid in an electromagnetic field

International Nuclear Information System (INIS)

Lai, H.M.; Suen, W.M.; Young, K.

1982-01-01

The force acting on a Clausius-Mossotti fluid in an electromagnetic field is evaluated microscopically. Owing to the modification of the two-particle density by the electric field, an additional mechanical force Δf/sup( M/) is found. When this is added to the electrical force f/sup( E/), the total force in the static case becomes identical to that deduced macroscopically by Helmholtz. The analysis is extended to various time-dependent cases, and it is pointed out that Δf/sup( M/) essentially assumes its static value on time scales longer than T/sub c/, the relaxation time of the two-particle density, but is otherwise negligibly small. Thus Peierls's theory of the momentum of light is valid only for pulses much shorter than T/sub c/; the necessary correction due to Δf/sup( M/) in other cases is given and discussed

Microtubules as mechanical force sensors.

Science.gov (United States)

Karafyllidis, Ioannis G; Lagoudas, Dimitris C

2007-03-01

Microtubules are polymers of tubulin subunits (dimers) arranged on a hexagonal lattice. Each tubulin dimer comprises two monomers, the alpha-tubulin and beta-tubulin, and can be found in two states. In the first state a mobile negative charge is located into the alpha-tubulin monomer and in the second into the beta-tubulin monomer. Each tubulin dimer is modeled as an electrical dipole coupled to its neighbors by electrostatic forces. The location of the mobile charge in each dimer depends on the location of the charges in the dimer's neighborhood. Mechanical forces that act on the microtubule affect the distances between the dimers and alter the electrostatic potential. Changes in this potential affect the mobile negative charge location in each dimer and the charge distribution in the microtubule. The net effect is that mechanical forces affect the charge distribution in microtubules. We propose to exploit this effect and use microtubules as mechanical force sensors. We model each dimer as a two-state quantum system and, following the quantum computation paradigm, we use discrete quantum random walk on the hexagonal microtubule lattice to determine the charge distribution. Different forces applied on the microtubule are modeled as different coin biases leading to different probability distributions of the quantum walker location, which are directly connected to different charge distributions. Simulation results show that there is a strong indication that microtubules can be used as mechanical force sensors and that they can also detect the force directions and magnitudes.

Augmentation of forced-convection heat transfer by applying electric fields to disturb flow near a wall

International Nuclear Information System (INIS)

Nariai, H.; Ishiguro, H.; Nagata, S.; Yabe, A.

1991-01-01

This paper reports on the augmentation effect of electrohydrodynamically (EHD) induced flow disturbance on forced-convection heat transfer in a channel that was experimentally investigated in order to determine the applicability of the enhanced heat transfer into a low- pressure drop heat exchanger, such as a high-performance oil cooler. The investigation is mainly based on the study carried out on the unique point where the flow is disturbed actively and controllably by applying electric fields between the wall and array of wire electrodes installed near the wall along the main stream. The liquid mixture of refrigerant R113 (96 wt %) and ethanol (4 wt %), called Fronsorubu AE, was selected as a working fluid. Heat transfer was found to be promoted intensely in the turbulent flow as well as in the laminar flow, up to a factor of about twenty-three in the case of laminar flow. It is noteworthy that the rate of increase in heat transfer coefficient is larger compared to that in the pressure drop. From a measurement of velocities by a laser Doppler velocimeter, it was made clear that the electrohydrodynamically induced flow disturbance brings about large heat transfer coefficients

Study on force mechanism for therapeutic effect of pushing manipulation with one-finger meditation base on similarity analysis of force and waveform.

Science.gov (United States)

Fang, Lei; Fang, Min; Guo, Min-Min

2016-12-27

To reveal the force mechanism for therapeutic effect of pushing manipulation with one-finger meditation. A total of 15 participants were recruited in this study and assigned to an expert group, a skilled group and a novice group, with 5 participants in each group. Mechanical signals were collected from a biomechanical testing platform, and these data were further observed via similarity analysis and cluster analysis. Comparing the force waveforms of manipulation revealed that the manipulation forces were similar between the expert group and the skilled group (P>0.05). The mean value of vertical force was 9.8 N, and 95% CI rang from 6.37 to 14.70 N, but there were significant differences compared with the novice group (PPushing manipulation with one-finger meditation is a kind of light stimulation manipulation on the acupoint, and force characteristics of double waveforms continuously alternated during manual operation.

Effect of demand management on regulated and deregulated electricity sectors

International Nuclear Information System (INIS)

Fahrioglu, Murat

2016-01-01

Our society derives a quantifiable benefit from electric power. In particular, forced outages or blackouts have enormous consequences on society, one of which is loss of economic surplus. The society relies on having a continuous supply of electrical energy. Some customers may willingly risk this continuous supply and participate in demand management programs for electrical power. If the power system grid is in trouble, electric utilities need to have demand relief. Customers willing to reduce their demand to help the system can receive an incentive fee for helping the utilities. Demand relief can be system wide or location specific. Sometimes it can be more effective to fix the electrical demand vs. supply imbalance from the demand side. The value of demand management contracts is greatly affected by customer location. Inclusion of locational attributes into the contract design procedure increases the effectiveness of the contracts by helping a utility get more value from its demand management programs. Independent System Operators and regulators, among others, can also benefit from effective demand management. This paper will investigate how this type of demand management contracts can help the electricity sector both in regulated and deregulated environments. - Highlights: • Demand management can help prevent forced electricity outages. • Both electric utilities and ISOs can use demand management. • Regulated and deregulated electricity sectors can benefit from demand management. • Demand management contracts can be effectively used in power system grids.

Traction force dynamics predict gap formation in activated endothelium

International Nuclear Information System (INIS)

Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L.

2016-01-01

In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

Traction force dynamics predict gap formation in activated endothelium

Energy Technology Data Exchange (ETDEWEB)

Valent, Erik T.; Nieuw Amerongen, Geerten P. van; Hinsbergh, Victor W.M. van; Hordijk, Peter L., E-mail: p.hordijk@vumc.nl

2016-09-10

In many pathological conditions the endothelium becomes activated and dysfunctional, resulting in hyperpermeability and plasma leakage. No specific therapies are available yet to control endothelial barrier function, which is regulated by inter-endothelial junctions and the generation of acto-myosin-based contractile forces in the context of cell-cell and cell-matrix interactions. However, the spatiotemporal distribution and stimulus-induced reorganization of these integral forces remain largely unknown. Traction force microscopy of human endothelial monolayers was used to visualize contractile forces in resting cells and during thrombin-induced hyperpermeability. Simultaneously, information about endothelial monolayer integrity, adherens junctions and cytoskeletal proteins (F-actin) were captured. This revealed a heterogeneous distribution of traction forces, with nuclear areas showing lower and cell-cell junctions higher traction forces than the whole-monolayer average. Moreover, junctional forces were asymmetrically distributed among neighboring cells. Force vector orientation analysis showed a good correlation with the alignment of F-actin and revealed contractile forces in newly formed filopodia and lamellipodia-like protrusions within the monolayer. Finally, unstable areas, showing high force fluctuations within the monolayer were prone to form inter-endothelial gaps upon stimulation with thrombin. To conclude, contractile traction forces are heterogeneously distributed within endothelial monolayers and force instability, rather than force magnitude, predicts the stimulus-induced formation of intercellular gaps. - Highlights: • Endothelial monolayers exert dynamic- and heterogeneous traction forces. • High traction forces correlate with junctional areas and the F-actin cytoskeleton. • Newly formed inter-endothelial gaps are characterized by opposing traction forces. • Force stability is a key feature controlling endothelial permeability.

A Bumpy Ride for Electric Cars

International Nuclear Information System (INIS)

Bonnaure, Pierre

2018-01-01

In July 2017 Nicolas Hulot, the French Minister of Ecological and Inclusive Transition, presented a climate plan featuring an end to electricity generation from coal by 2022, a reduction in the nuclear component of electricity supply by one third, a total ban on the sale of petrol or diesel cars by 2040 and an incentive scheme designed gradually to remove polluting vehicles from the roads. Other European partners are following suit and promoting the spread of electric vehicles (Norway, Germany, Netherlands etc.). Yet is this the panacea that will meet the targets for greenhouse gas reduction in the battle against climate change? Futuribles examines the question in this issue, first through this article by Pierre Bonnaure that assesses the forces driving the spread of electric cars and the impediments to that process, and then with an article by Veronique Lamblin offering a general overview of electric road vehicles. (author)

CALCULATION OF A MECHANICAL CHARACTERISTIC OF ELECTRIC TRACTION MOTOR OF ELECTRIC VEHICLE

Directory of Open Access Journals (Sweden)

Phuong Le Ngo

2017-01-01

Full Text Available The traction characteristic of an electric vehicle is the main characteristic of mechanical system that reflects its key performance indicators. Implementation of the traction characteristic is based on controlling angular speed and torque of electric traction motor in an automatic control system. The static mechanical characteristic of an electric traction motor in an automatic control system is the most important characteristic that determines weight, size and operating characteristics of an electric traction motor and serves as the basis for design. The most common variants of constructive implementation of a traction electric drive are analyzed, and a scheme is chosen for further design. Lagrange’s equation for electric mechanical system with one degree of freedom is written in generalized coordinates. In order to determine the generalized forces, elementary operation of all moments influencing on a moving car has been calculated. The resulting equation of motion of the electric vehicle corresponding to the design scheme, as well as the expressions for calculation of characteristic points of static mechanical characteristics of traction motor (i.e. the maximum and minimum time, minimum power are obtained. In order to determine the nominal values of the angular velocity and the power of electric traction motor, a method based on ensuring the movement of the vehicle in the standard cycle has been developed. The method makes it possible to calculate characteristic points of the mechanical characteristic with the lowest possible power rating. The algorithm for calculation of mechanical characteristics of the motor is presented. The method was applied to calculate static mechanical characteristic of an electric traction motor for a small urban electric truck.

Insulating nanoparticles on YBa2Cu3O7-δ thin films revealed by comparison of atomic force and scanning tunneling microscopy

International Nuclear Information System (INIS)

Thomson, R.E.; Moreland, J.; Missert, N.; Rudman, D.A.; Sanders, S.C.; Cole, B.F.

1993-01-01

The surface topography of YBa 2 Cu 3 O 7-δ thin films has been studied with both atomic force microscopy (AFM) and scanning tunneling microscopy (STM). The AFM images reveal a high density of small distinct nanoparticles, 10--50 nm across and 5--20 nm high, which do not appear in STM images of the same samples. In addition, we have shown that scanning the STM tip across the surface breaks off these particles and moves them to the edge of the scanned area, where they can later be imaged with the AFM

Reintroducing the concept of force into relativity theory

International Nuclear Information System (INIS)

Mahajan, S.; Qadir, A.; Valanju, P.

1979-07-01

It is suggested that re-introducing forces into relativity theory may provide new insights and results. A look at the Kerr-Newmann geometry, and special cases of it, from this viewpoint indicates that there can be a short range repulsion in general. This repulsion suggests that naked singularities may be physically feasible. It is also found that there is a gravito-electric repulsion which would be important to consider in a grand unification scheme of strong, weak and electromagnetic forces. 8 references

Reintroducing the concept of force into relativity theory

Energy Technology Data Exchange (ETDEWEB)

Mahajan, S.; Qadir, A.; Valanju, P.

1979-07-01

It is suggested that re-introducing forces into relativity theory may provide new insights and results. A look at the Kerr-Newmann geometry, and special cases of it, from this viewpoint indicates that there can be a short range repulsion in general. This repulsion suggests that naked singularities may be physically feasible. It is also found that there is a gravito-electric repulsion which would be important to consider in a grand unification scheme of strong, weak and electromagnetic forces. 8 references.

Electrical actuation of electrically conducting and insulating droplets using ac and dc voltages

International Nuclear Information System (INIS)

Kumari, N; Bahadur, V; Garimella, S V

2008-01-01

Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets using dc voltages (classical electrowetting). Electrical actuation of conducting droplets using ac voltages and the actuation of insulating droplets (using dc or ac voltages) has remained relatively unexplored. This paper utilizes an energy-minimization-based analytical framework to study the electrical actuation of a liquid droplet (electrically conducting or insulating) under ac actuation. It is shown that the electromechanical regimes of classical electrowetting, electrowetting under ac actuation and insulating droplet actuation can be extracted from the generic electromechanical actuation framework, depending on the electrical properties of the droplet, the underlying dielectric layer and the frequency of the actuation voltage. This paper also presents experiments which quantify the influence of the ac frequency and the electrical properties of the droplet on its velocity under electrical actuation. The velocities of droplets moving between two parallel plates under ac actuation are experimentally measured; these velocities are then related to the actuation force on the droplet which is predicted by the electromechanical model developed in this work. It is seen that the droplet velocities are strongly dependent on the frequency of the ac actuation voltage; the cut-off ac frequency, above which the droplet fails to actuate, is experimentally determined and related to the electrical conductivity of the liquid. This paper then analyzes and directly compares the various electromechanical regimes for the actuation of droplets in microfluidic applications

External Force Estimation for Teleoperation Based on Proprioceptive Sensors

Directory of Open Access Journals (Sweden)

Enrique del Sol

2014-03-01

Full Text Available This paper establishes an approach to external force estimation for telerobotic control in radioactive environments by the use of an identified manipulator model and pressure sensors, without employing a force/torque sensor. The advantages of - and need for - force feedback have been well-established in the field of telerobotics, where electrical and back-drivable manipulators have traditionally been used. This research proposes a methodology employing hydraulic robots for telerobotics tasks based on a model identification scheme. Comparative results of a force sensor and the proposed approach using a hydraulic telemanipulator are presented under different conditions. This approach not only presents a cost effective solution but also a methodology for force estimation in radioactive environments, where the dose rates limit the use of electronic devices such as sensing equipment.

Insuring unit failures in electricity markets

International Nuclear Information System (INIS)

Pineda, S.; Conejo, A.J.; Carrion, M.

2010-01-01

An electric energy producer participates in futures markets in the hope of hedging the risk of trading in the pool. However, this producer is required to supply the energy associated with all its signed forward contracts even if some of its units are forced out due to unexpected failures. In this case, the producer must purchase some of the energy needed to meet its futures market commitments in the pool, which may result in high losses if the pool prices happen to be higher than the forward contract prices. To mitigate these losses, the producer can take out insurance against the forced outages of its units. Using a stochastic programming model, this paper analyzes the convenience of signing an insurance against unit failure by an electric energy producer and its impact on forward contracting decisions. Results from a realistic case study are provided and analyzed.

The Role of the Electrostatic Force in Spore Adhesion

Energy Technology Data Exchange (ETDEWEB)

Chung, Eunhyea [Georgia Institute of Technology; Yiacoumi, Sotira [Georgia Institute of Technology; Lee, Ida [University of Tennessee, Knoxville (UTK); Tsouris, Costas [ORNL

2010-01-01

Electrostatic force is investigated as one of the components of the adhesion force between Bacillus thuringiensis (Bt) spores and planar surfaces. The surface potentials of a Bt spore and a mica surface are experimentally obtained using a combined atomic force microscopy (AFM)-scanning surface potential microscopy technique. On the basis of experimental information, the surface charge density of the spores is estimated at 0.03 {micro}C/cm{sup 2} at 20% relative humidity and decreases with increasing humidity. The Coulombic force is introduced for the spore-mica system (both charged, nonconductive surfaces), and an electrostatic image force is introduced to the spore-gold system because gold is electrically conductive. The Coulombic force for spore-mica is repulsive because the components are similarly charged, while the image force for the spore-gold system is attractive. The magnitude of both forces decreases with increasing humidity. The electrostatic forces are added to other force components, e.g., van der Waals and capillary forces, to obtain the adhesion force for each system. The adhesion forces measured by AFM are compared to the estimated values. It is shown that the electrostatic (Coulombic and image) forces play a significant role in the adhesion force between spores and planar surfaces.

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

Science.gov (United States)

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (coefficients of about 100 pC/N. The level of harvested electrical power for CBPEHTs is on the order of microW even at resonance mode. In order to harvest more electrical energy across broader bandwidth, high effective piezoelectric coefficient structures are needed. In this study, we investigate a "33" longitudinal mode, piezoelectric PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective

Voluntary low-force contraction elicits prolonged low-frequency fatigue and changes in surface electromyography and mechanomyography

DEFF Research Database (Denmark)

Blangsted, Anne Katrine; Sjøgaard, Gisela; Madeleine, Pascal

2005-01-01

Controversies exist regarding objective documentation of fatigue development with low-force contractions. We hypothesized that non-exhaustive, low-force muscle contraction may induce prolonged low-frequency fatigue (LFF) that in the subsequent recovery period is detectable by electromyography (EMG......) and in particular mechanomyography (MMG) during low-force rather than high-force test contractions. Seven subjects performed static wrist extension at 10% maximal voluntary contraction (MVC) for 10 min (10%MVC10 min). Wrist force response to electrical stimulation of extensor carpi radialis muscle (ECR) quantified...... LFF. EMG and MMG were recorded from ECR during static test contractions at 5% and 80% MVC. Electrical stimulation, MVC, and test contractions were performed before 10%MVC10 min and at 10, 30, 90 and 150 min recovery. In spite of no changes in MVC, LFF persisted up to 150 min recovery but did...

Electricity diversification, decentralization, and decarbonization: The role of U.S. state energy policy

Science.gov (United States)

Carley, Sanya

In response to mounting concerns about climate change and an over-dependence on fossil fuels, U.S. state governments have assumed leadership roles in energy policy. State leaders across the country have constructed policies that target electricity sector operations, and aim to increase the percentage of renewable electricity generation, increase the use of distributed generation, and decrease carbon footprints. The policy literature, however, lacks compelling empirical evidence that state initiatives toward these ends are effective. This research seeks to contribute empirical insights that can help fill this void in the literature, and advance policy knowledge about the efficacy of these instruments. This three-essay dissertation focuses on the assessment of state energy policy instruments aimed at the diversification, decentralization, and decarbonization of the U.S. electricity sector. The first essay considers the effects of state efforts to diversify electricity portfolios via increases in renewable energy. This essay asks: are state-level renewable portfolio standards (RPS) effective at increasing renewable energy deployment, as well as the share of renewable energy out of the total generation mix? Empirical results demonstrate that RPS policies so far are effectively encouraging total renewable energy deployment, but not the percentage of renewable energy generation. The second essay considers state policy efforts to decentralize the U.S. electricity sector via instruments that remove barriers to distributed generation (DG) deployment. The primary question this essay addresses is whether the removal of legal barriers acts as a primary motivating factor for DG deployment. Empirical results reveal that net metering policies are positively associated with DG deployment; interconnection standards significantly increase the likelihood that end-users will adopt DG capacity; and utility DG adoption is related to standard market forces. The third essay asks: what are

Plasma rotation by electric and magnetic fields in a discharge cylinder

Science.gov (United States)

Wilhelm, H. E.; Hong, S. H.

1977-01-01

A theoretical model for an electric discharge consisting of a spatially diverging plasma sustained electrically between a small ring cathode and a larger ring anode in a cylindrical chamber with an axial magnetic field is developed to study the rotation of the discharge plasma in the crossed electric and magnetic fields. The associated boundary-value problem for the coupled partial differential equations which describe the electric potential and the plasma velocity fields is solved in closed form. The electric field, current density, and velocity distributions are discussed in terms of the Hartmann number and the Hall coefficient. As a result of Lorentz forces, the plasma rotates with speeds as high as 1 million cm/sec around its axis of symmetry at typical conditions. As an application, it is noted that rotating discharges of this type could be used to develop a high-density plasma-ultracentrifuge driven by j x B forces, in which the lighter (heavier) ion and atom components would be enriched in (off) the center of the discharge cylinder.

Greenhouse gas emissions behaviour in electric sector during 1990-1999

International Nuclear Information System (INIS)

Lopez Lopez, Ileana; Perez Martin, David

2000-01-01

The electricity contributes to development and enhances the life level of population. Nevertheless, it generation is one of the major contributors to Greenhouse Gas emissions over the world. In Cuba 94% of electricity is generated based on fossil fuel. During first part of last decade the economic crisis forced the reduction of electricity generation and increased the participation of domestic crude oil in electricity generation. Paper characterizes the electricity generation during 1990-1999 and the fuel mix used. The methodology for emissions calculations is presented and the environment implications of domestic crude oil utilization are shown. Conclusions and recommendations are offered. (author)

A Piezoelectric PZT Ceramic Mulitlayer Stack for Energy Harvesting Under Dynamic Forces

Science.gov (United States)

Xu, Tian-Bing; Siochi, Emilie J.; Kang, Jin Ho; Zuo, Lei; Zhou, Wanlu; Tang, Xiudong; Jiang, Xiaoning

2011-01-01

Piezoelectric energy harvesting transducers (PEHTs) are commonly used in motion/vibration energy scavenging devices. To date, most researchers have focused on energy harvesting at narrow bandwidths around the mechanical resonance frequency, and most piezoelectric harvesting devices reported in the literature have very low effective piezoelectric coefficient (d(sub eff)) (PZT ceramic multilayer stack (PZT-Stack) with high effective piezoelectric coefficient for high-performance PEHTs. The PZT-Stack is composed of 300 layers of 0.1 mm thick PZT plates, with overall dimensions of 32.4 mm X 7.0 mm X 7.0 mm. Experiments were carried out with dynamic forces in a broad bandwidth ranging from 0.5 Hz to 25 kHz. The measured results show that the effective piezoelectric coefficient of the PZT-stack is about 1 X 10(exp 5) pC/N at off-resonance frequencies and 1.39 X 10(exp 6) pC/N at resonance, which is order of magnitude larger than that of traditional PEHTs. The effective piezoelectric coefficients (d(sub eff)) do not change significantly with applied dynamic forces having root mean square (RMS) values ranging from 1 N to 40 N. In resonance mode, 231 mW of electrical power was harvested at 2479 Hz with a dynamic force of 11.6 N(sub rms), and 7.6 mW of electrical power was generated at a frequency of 2114 Hz with 1 N(sub rms) dynamic force. In off-resonance mode, an electrical power of 18.7 mW was obtained at 680 Hz with a 40 N(sub rms) dynamic force. A theoretical model of energy harvesting for the PZT-Stack is established. The modeled results matched well with experimental measurements. This study demonstrated that high effective piezoelectric coefficient structures enable PEHTs to harvest more electrical energy from mechanical vibrations or motions, suggesting an effective design for high-performance low-footprint PEHTs with potential applications in military, aerospace, and portable electronics. In addition, this study provides a route for using piezoelectric multilayer

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

CERN Document Server

Djurabekova, Flyura; Pohjonen, Aarne; Nordlund, Kai

2011-01-01

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

Magnetohydraulic flow through a packed bed of electrically conducting spheres

International Nuclear Information System (INIS)

Sanders, T.L.

1985-01-01

The flow of an electrically conducting fluid through a packed bed of electrically conducting spheres in the presence of a strong magnetic field constitutes a very complex flow situation due to the constant turning of the fluid in and out of magnetic field lines. The interaction of the orthogonal components of the velocity and magnetic field will induce electric fields that are orthogonal to both and the electric fields in turn can cause currents that interact with the magnetic field to generate forces against the direction of flow. The strengths of these generated forces depend primarily upon the closure paths taken by the induced currents which, in turn, depend upon the relative ratio of the electrical resistance of the solid spheres to that of the fluid. Both experimental and analytical analyses of the slow flow of a eutectic mixture of sodium and potassium (NaK) through packed cylinders containing stainless steel spheres in the presence of a strong transverse magnetic field were completed. A theory of magnetohydraulic flow is developed by analogy with the development of hydraulic radius theories of flow through porous media. An exact regional analysis is successfully applied to an infinite bed of electrically conducting spheres with a conducting or non-conducting constraining wall on one side. The equations derived are solved for many different combinations of flowrate, magnetic field strength, porosity, and electrical resistance ratio

MEASUREMENTS OF SHOCK WAVE FORCE IN SHOCK TUBE WITH INDIRECT METHODS

Directory of Open Access Journals (Sweden)

Mario Dobrilović

2005-12-01

Full Text Available Tests have been conducted at the “Laboratory for testing of civil explosives, detonators, electrical detonators and pyrotechnical materials”, Department for mining and geotechnics of the Faculty of mining, geology and petroleum engineering, University of Zagreb with the purpose of designing a detonator that would unite advantages of a non-electric system and the precision in regulation of time delay in electronic initiation system. Sum of energy released by the wave force in shock tube is a pre-condition for operation of the new detonator, and measurement of wave force is the first step in determining the sum of energy. The sum of energy is measured indirectly, based on two principles: movement sensors and strain.

Nanoparticle movement: Plasmonic forces and physical constraints

International Nuclear Information System (INIS)

Batson, P.E.; Reyes-Coronado, A.; Barrera, R.G.; Rivacoba, A.; Echenique, P.M.; Aizpurua, J.

2012-01-01

Nanoparticle structures observed in aberration-corrected electron microscopes exhibit many types of behavior, some of which are dominated by intrinsic conditions, unrelated to the microscope environment. Some behaviors are clearly driven by the electron beam, however, and the question arises as to whether these are similar to intrinsic mechanisms, useful for understanding nanoscale behavior, or whether they should be regarded as unwanted modification of as-built specimens. We have studied a particular kind of beam–specimen interaction – plasmon dielectric forces caused by the electric fields imposed by a passing swift electron – identifying four types of forced motion, including both attractive and repulsive forces on single nanoparticles, and coalescent and non-coalescent forces in groups of two or more nanoparticles. We suggest that these forces might be useful for deliberate electron beam guided movement of nanoparticles. -- Highlights: ► We investigate the interaction of metal nanoparticles with a high energy electron beam. ► We find forces ranging from 0.1 to 50 pN forces between the metal particles and the beam. ► At moderate distances, dielectric forces are usually small and attractive. ► At sub-Nm distances the forces become repulsive, pushing nanoparticles away from the electron beam. ► While the repulsive behavior is predicted by electromagnetic theory, the detailed origin of the behavior is not yet understood.

Distributions of electric and elastic fields at domain boundaries

International Nuclear Information System (INIS)

Novak, Josef; Fousek, Jan; Maryska, Jiri; Marvan, Milan

2005-01-01

In this paper we describe the application of the finite element method (FEM) in modelling spatial distributions of electric and elastic fields in a ferroelectric crystals with two domains separated by a 90 deg. domain wall. The domain boundary is idealized as a two-dimensional defect in an electro-elastic continuum. It represents the source of inhomogenity and internal distortion in both elastic and electric fields. The main results are distributions of electric field, strain and mechanical force along the domain boundary

Rare-earth-free propulsion motors for electric vehicles: a technology review

OpenAIRE

Riba Ruiz, Jordi-Roger; Lopez Torres, Carlos; Romeral Martínez, José Luis; García Espinosa, Antonio

2016-01-01

Several factors including fossil fuels scarcity, prices volatility, greenhouse gas emissions or current pollution levels in metropolitan areas are forcing the development of greener transportation systems based on more efficient electric and hybrid vehicles. Most of the current hybrid electric vehicles use electric motors containing powerful rare-earth permanent magnets. However, both private companies and estates are aware of possible future shortages, price uncertainty and geographical conc...

Neural adaptations to electrical stimulation strength training

NARCIS (Netherlands)

Hortobagyi, Tibor; Maffiuletti, Nicola A.

2011-01-01

This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there

Forecasting electricity consumption in Pakistan: the way forward

International Nuclear Information System (INIS)

Hussain, Anwar; Rahman, Muhammad; Memon, Junaid Alam

2016-01-01

Growing shortfall of electricity in Pakistan affects almost all sectors of its economy. For proper policy formulation, it is imperative to have reliable forecasts of electricity consumption. This paper applies Holt-Winter and Autoregressive Integrated Moving Average (ARIMA) models on time series secondary data from 1980 to 2011 to forecast total and component wise electricity consumption in Pakistan. Results reveal that Holt-Winter is the appropriate model for forecasting electricity consumption in Pakistan. It also suggests that electricity consumption would continue to increase throughout the projected period and widen the consumption-production gap in case of failure to respond the issue appropriately. It further reveals that demand would be highest in the household sector as compared to all other sectors and the increase in the energy generation would be less than the increase in total electricity consumption throughout the projected period. The study discuss various options to reduce the demand-supply gap and provide reliable electricity to different sectors of the economy. - Highlights: • We forecast total and component wise electricity consumption for Pakistan. • Electricity shortfall in Pakistan will increase in future if same situation exists. • Various options exist to cope with the electricity crisis in the country. • Holt-winter model gives best forecasts for electricity consumption in the country.

Electricity costs in liberalized market

International Nuclear Information System (INIS)

Barkans, J.; Junghans, G.

2006-01-01

In the liberalized electricity market the flexible demand determines the operation of power plants. Under market conditions the producers are forced to compete, and their power plants are normally loaded in order of increasing prices. The electricity costs consist of fixed and variable components, and the competition among producers simulates minimization of both the components. Considering the fixed costs (including maintenance, depreciation, capital costs and other permanent costs not depending on production) to be known, the total electricity costs in different operating conditions are based on the economic characteristics and the equipment load of a power plant. The paper describes the method for determination of electricity costs for condensing thermal power plants with permanent steam take-off for regeneration purposes and adjustable steam take-off for the needs of local heat energy consumers. The marginal costs for CHP plants are determined considering a number of different steam take-off from a turbine. At the electricity cost determination, auxiliary services also are taken into account. These can be reduced by adjusting the rotational speed of electric motors. The paper also shows how to determine the electricity costs for gas turbines, combined cycle gas turbines, and nuclear power plants. The position of hydro power plants among other PPs in the free market is also analysed. (authors)

Multiscale response of ionic systems to a spatially varying electric field

DEFF Research Database (Denmark)

Hansen, Jesper Schmidt

2017-01-01

In this paper the response of ionic systems subjected to a spatially varying electric field is studied. Following the Nernst-Planck equation, two forces driving the mass flux are present, namely, the concentration gradient and the electric potential gradient. The mass flux due to the concentratio...

Design rules for biomolecular adhesion: lessons from force measurements.

Science.gov (United States)

Leckband, Deborah

2010-01-01

Cell adhesion to matrix, other cells, or pathogens plays a pivotal role in many processes in biomolecular engineering. Early macroscopic methods of quantifying adhesion led to the development of quantitative models of cell adhesion and migration. The more recent use of sensitive probes to quantify the forces that alter or manipulate adhesion proteins has revealed much greater functional diversity than was apparent from population average measurements of cell adhesion. This review highlights theoretical and experimental methods that identified force-dependent molecular properties that are central to the biological activity of adhesion proteins. Experimental and theoretical methods emphasized in this review include the surface force apparatus, atomic force microscopy, and vesicle-based probes. Specific examples given illustrate how these tools have revealed unique properties of adhesion proteins and their structural origins.

Shipwreck rates reveal Caribbean tropical cyclone response to past radiative forcing.

Science.gov (United States)

Trouet, Valerie; Harley, Grant L; Domínguez-Delmás, Marta

2016-03-22

Assessing the impact of future climate change on North Atlantic tropical cyclone (TC) activity is of crucial societal importance, but the limited quantity and quality of observational records interferes with the skill of future TC projections. In particular, North Atlantic TC response to radiative forcing is poorly understood and creates the dominant source of uncertainty for twenty-first-century projections. Here, we study TC variability in the Caribbean during the Maunder Minimum (MM; 1645-1715 CE), a period defined by the most severe reduction in solar irradiance in documented history (1610-present). For this purpose, we combine a documentary time series of Spanish shipwrecks in the Caribbean (1495-1825 CE) with a tree-growth suppression chronology from the Florida Keys (1707-2009 CE). We find a 75% reduction in decadal-scale Caribbean TC activity during the MM, which suggests modulation of the influence of reduced solar irradiance by the cumulative effect of cool North Atlantic sea surface temperatures, El Niño-like conditions, and a negative phase of the North Atlantic Oscillation. Our results emphasize the need to enhance our understanding of the response of these oceanic and atmospheric circulation patterns to radiative forcing and climate change to improve the skill of future TC projections.

Casimir forces in the time domain: Theory

International Nuclear Information System (INIS)

Rodriguez, Alejandro W.; McCauley, Alexander P.; Joannopoulos, John D.; Johnson, Steven G.

2009-01-01

We present a method to compute Casimir forces in arbitrary geometries and for arbitrary materials based on the finite-difference time-domain (FDTD) scheme. The method involves the time evolution of electric and magnetic fields in response to a set of current sources, in a modified medium with frequency-independent conductivity. The advantage of this approach is that it allows one to exploit existing FDTD software, without modification, to compute Casimir forces. In this paper, we focus on the derivation, implementation choices, and essential properties of the time-domain algorithm, both considered analytically and illustrated in the simplest parallel-plate geometry.

Coulomb's Electrical Measurements. Experiment No. 14.

Science.gov (United States)

Devons, Samuel

Presented is information related to the life and work of Charles Coulomb as well as detailed notes of his measurements of the distribution of electricity on conductors. The two methods that he used (the large torsion balance, and the timing of "force" oscillations) are described. (SA)

Control of forced vibrations of mechanical structures by an electromagnetic controller with a permanent magnet

DEFF Research Database (Denmark)

Stein, George Juraj; Darula, Radoslav; Sorokin, Sergey

2012-01-01

A theoretical analysis of an electromagnetic vibration controller is presented. The analyzed device consists of a pot-type iron core with a coil and a permanent magnet as a source of constant magnetic flux. The magnetic circuit is closed by a yoke, excited by an external harmonic mechanical force....... The so generated magnetic flux variation induces alternating voltage in the electric circuit, which is dissipated in a shunt resistor. The induced current driven through the coil generates magnetic force, which damps the excitation force and changes the damped natural frequency of the oscillatory system....... Due to the hysteretic effects in the magnetic material the internal losses influence the overall system’s performance. A mathematical model of the force balance in the oscillatory system is derived in a simplified, linearised form. The electric as well as mechanical system is modelled using lumped...

Forced Vibration Analysis for a FGPM Cylindrical Shell

Directory of Open Access Journals (Sweden)

Hong-Liang Dai

2013-01-01

Full Text Available This article presents an analytical study for forced vibration of a cylindrical shell which is composed of a functionally graded piezoelectric material (FGPM. The cylindrical shell is assumed to have two-constituent material distributions through the thickness of the structure, and material properties of the cylindrical shell are assumed to vary according to a power-law distribution in terms of the volume fractions for constituent materials, the exact solution for the forced vibration problem is presented. Numerical results are presented to show the effect of electric excitation, thermal load, mechanical load and volume exponent on the static and force vibration of the FGPM cylindrical shell. The goal of this investigation is to optimize the FGPM cylindrical shell in engineering, also the present solution can be used in the forced vibration analysis of cylindrical smart elements.

Electric rail gun application to space propulsion

International Nuclear Information System (INIS)

Barber, J.P.

1979-01-01

The paper examines the possibility of using the DC electric gun principles as a space vehicle propulsion system, capable of producing intermediate thrust levels. The application of an electromagnetic launch technique, called the DC electric rail gun, to the space propulsion concept of O'Neill, is examined. It is determined that the DC electric rail gun offers very high projectile accelerations and a very significant potential for reducing the size and mass of a reaction motor for space application. A detailed description of rail gun principles is given and some simple expressions for the accelerating force, gun impedance, power supply requirements, and system performance are discussed

Noether symmetries of discrete mechanico–electrical systems

International Nuclear Information System (INIS)

Fu Jingli; Xie Fengping; Chen Benyong

2008-01-01

This paper focuses on studying Noether symmetries and conservation laws of the discrete mechanico-electrical systems with the nonconservative and the dissipative forces. Based on the invariance of discrete Hamilton action of the systems under the infinitesimal transformation with respect to the generalized coordinates, the generalized electrical quantities and time, it presents the discrete analogue of variational principle, the discrete analogue of Lagrange–Maxwell equations, the discrete analogue of Noether theorems for Lagrange–Maxwell and Lagrange mechanico-electrical systems. Also, the discrete Noether operator identity and the discrete Noether-type conservation laws are obtained for these systems. An actual example is given to illustrate these results. (general)

Optimal Allocation of Thermal-Electric Decoupling Systems Based on the National Economy by an Improved Conjugate Gradient Method

Directory of Open Access Journals (Sweden)

Shuang Rong

2015-12-01

Full Text Available Aiming to relieve the large amount of wind power curtailment during the heating period in the North China region, a thermal-electric decoupling (TED approach is proposed to both bring down the constraint of forced power output of combined heat and power plants and increase the electric load level during valley load times that assist the power grid in consuming more wind power. The operating principles of the thermal-electric decoupling approach is described, the mathematical model of its profits is developed, the constraint conditions of its operation are listed, also, an improved parallel conjugate gradient is utilized to bypass the saddle problem and accelerate the optimal speed. Numerical simulations are implemented and reveal an optimal allocation of TED which with a rated power of 280 MW and 185 MWh heat storage capacity are possible. This allocation of TED could bring approximately 16.9 billion Yuan of economic profit and consume more than 80% of the surplus wind energy which would be curtailed without the participation of TED. The results in this article verify the effectiveness of this method that could provide a referential guidance for thermal-electric decoupling system allocation in practice.

Hydrogeological characterisation using cross-borehole ground penetration radar and electrical resistivity tomography

DEFF Research Database (Denmark)

Zibar, Majken Caroline Looms

2007-01-01

was characterized by ~30 m thick unsaturated zone consisting mainly of sands of varying coarseness. Following an instrumentation of 16 boreholes two geophysical methods (cross-borehole ground penetrating radar and electrical resistivity tomography) were applied during natural precipitation and forced infiltration...... properties of the subsurface. On the other hand, volumetric moisture content variations of up to 5% were observed during a 20-day long forced infiltration experiment. The cross-borehole electrical resistance tomography and ground penetrating radar data collected during this experiment were subsequently....... The methods provided estimates of soil moisture content and electrical resistivity variations among 12 m deep boreholes located 5 – 7 m apart. The moisture content change following natural precipitation was observed to be practically negligible, providing minimal information to constrain the dynamic...

Casimir forces and geometry

International Nuclear Information System (INIS)

Buescher, R.

2005-01-01

Casimir interactions are interactions induced by quantum vacuum fluctuations and thermal fluctuations of the electromagnetic field. Using a path integral quantization for the gauge field, an effective Gaussian action will be derived which is the starting point to compute Casimir forces between macroscopic objects analytically and numerically. No assumptions about the independence of the material and shape dependent contributions to the interaction are made. We study the limit of flat surfaces in further detail and obtain a concise derivation of Lifshitz' theory of molecular forces. For the case of ideally conducting boundaries, the Gaussian action will be calculated explicitly. Both limiting cases are also discussed within the framework of a scalar field quantization approach, which is applicable for translationally invariant geometries. We develop a non-perturbative approach to calculate the Casimir interaction from the Gaussian action for periodically deformed and ideally conducting objects numerically. The obtained results reveal two different scaling regimes for the Casimir force as a function of the distance between the objects, their deformation wavelength and -amplitude. The results confirm that the interaction is non-additive, especially in the presence of strong geometric deformations. Furthermore, the numerical approach is extended to calculate lateral Casimir forces. The results are consistent with the results of the proximity-force approximation for large deformation wavelengths. A qualitatively different behaviour between the normal and lateral force is revealed. We also establish a relation between the boundary induced change of the of the density of states for the scalar Helmholtz equation and the Casimir interaction using the path integral method. For statically deformed boundaries, this relation can be expressed as a novel trace formula, which is formally similar to the so-called Krein-Friedel-Lloyd formula. While the latter formula describes the

The Electromagnetic Force between Two Moving Charges

Science.gov (United States)

Minkin, Leonid; Shapovalov, Alexander S.

2018-01-01

A simple model of parallel motion of two point charges and the subsequent analysis of the electromagnetic field transformation invariant quantity are considered. It is shown that ignoring the coupling of electric and magnetic fields, as is done in some introductory physics books, can lead to miscalculations of the force between moving charges.…

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

Energy Technology Data Exchange (ETDEWEB)

Jiang, Xiaohong; Huang, Xiaowei; Zhang, Jiajia; Lu, Zhijuan; Wang, Hua; Du, Zuliang, E-mail: zld@henu.edu.cn [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng, 475004 (China)

2016-07-15

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.

Electric utility deregulation - A nuclear opportunity

International Nuclear Information System (INIS)

DeMella, J.R.

2002-01-01

The implications of electric deregulation are and will continue to be pervasive and significant. Not only will the fundamental monopoly regulatory concepts of managing electric utilities change but deregulation will have a profound and dramatic impact on the way electric generating plants are managed and operated. In the past, under the various approaches to financial regulation, the economic benefits normally attributed to competition or that would have otherwise been derived from competitive or open market forces, were assumed to be embodied in and inherent to the various processes, methods and principles of financial oversight of utility companies by regional, state and municipal regulatory authorities. Traditionally, under the various forms of regulated monopolies, a utility company, in exchange for an exclusive franchise to produce and sell electricity in a particular region, was obligated to provide an adequate supply to all consumers wanting it, at a price that was 'just and reasonable'. The determination of adequate supply and reasonable price was a matter of interpretation by utility companies and their regulators. In essence, the ultimate economic benefits, normally attributed to price equilibrium, in balance with supply, demand and other market forces, were expected to be achieved through a complex, political process of financial regulatory oversight, in which utility companies were usually reimbursed for all annual expenses or their 'cost of service' and additionally allowed to earn a 'reasonable' rate of return on plant investments. The result was often escalating electric prices, over supplies of electric capacity, by justifying unnecessarily high reserve margins based on long planning horizons (typically 20 years or greater) with extrapolated demand requirements that were generally in excess of what actually occurred over time. Although the regulatory process varied from country or country and region-to-region, the fundamental principles, which

Experimental and theoretical analysis of a hybrid solar thermoelectric generator with forced convection cooling

Science.gov (United States)

Sundarraj, Pradeepkumar; Taylor, Robert A.; Banerjee, Debosmita; Maity, Dipak; Sinha Roy, Susanta

2017-01-01

Hybrid solar thermoelectric generators (HSTEGs) have garnered significant research attention recently due to their potential ability to cogenerate heat and electricity. In this paper, theoretical and experimental investigations of the electrical and thermal performance of a HSTEG system are reported. In order to validate the theoretical model, a laboratory scale HSTEG system (based on forced convection cooling) is developed. The HSTEG consists of six thermoelectric generator modules, an electrical heater, and a stainless steel cooling block. Our experimental analysis shows that the HSTEG is capable of producing a maximum electrical power output of 4.7 W, an electrical efficiency of 1.2% and thermal efficiency of 61% for an average temperature difference of 92 °C across the TEG modules with a heater power input of 382 W. These experimental results of the HSTEG system are found to be in good agreement with the theoretical prediction. This experimental/theoretical analysis can also serve as a guide for evaluating the performance of the HSTEG system with forced convection cooling.

Looking hard at the electroweak force

International Nuclear Information System (INIS)

Baur, Ulrich; Errede, Steven; Mueller, Thomas

1995-01-01

While recent experiments have beautifully confirmed many of the predictions of the electroweak unification of electromagnetism and the weak nuclear force, some direct consequences of the electroweak symmetry involve special properties of the three force carriers - the electrically charged W and neutral Z carrying the weak force and the photon of electromagnetism. These special properties have yet to be measured accurately. In the electroweak picture these force carriers (vector bosons) can interact with each other. These properties are 'non-abelian' - they are dependent on the order in which they are applied. [Most operations can be applied in any order, for example simple arithmetic: 6x(3+2) = (6x3)+(6x2). These are 'abelian'. An example of a non-abelian operator is the logarithm: log(x+y) does not equal log(x) + log(y).] Summarizing the current theoretical and experimental understanding of these self-interactions, and discussing the prospects of measuring them in future experiments, was the purpose of the ''International Symposium on Vector Boson Self-Interactions'' held earlier this year at UCLA, the first meeting entirely devoted to this topic. Progress in measuring the selfcouplings of vector bosons has been fueled recently by the CDF and DO Collaborations at Fermilab's protonantiproton collider. Using data from vector boson pair production, these studies are extracting information on the WW-photon, WWZ and ZZphoton interactions, as well as the magnetic and electric quadrupole moments of the W boson. At UCLA, Hiro Aihara (Berkeley) and Theresa Fuess (Argonne) summarized the CDF and DO results from the 1992-93 run. Information on potential ZZ-gamma interactions can also be gained from single photon production at CERN's LEP electronpositron collider, as detailed by Peter Maettig (Bonn), and from rare B meson decays, reviewed by Steve Playfer (Syracuse)

Hyperexcitability to electrical stimulation and accelerated muscle fatiguability of taut bands in rats.

Science.gov (United States)

Wang, Yong-Hui; Yin, Ming-Jing; Fan, Zhen-Zhen; Arendt-Nielsen, Lars; Ge, Hong-You; Yue, Shou-Wei

2014-04-01

Myofascial trigger points contribute significantly to musculoskeletal pain and motor dysfunction and may be associated with accelerated muscle fatiguability. The aim of this study was to investigate the electrically induced force and fatigue characteristics of muscle taut bands in rats. Muscle taut bands were dissected out and subjected to trains of electrical stimulation. The electrical threshold intensity for muscle contraction and maximum contraction force (MCF), electrical intensity dependent fatigue and electrical frequency dependent fatigue characteristics were assessed in three different sessions (n=10 each) and compared with non-taut bands in the biceps femoris muscle. The threshold intensity for muscle contraction and MCF at the 10th, 15th and 20th intensity dependent fatigue stimuli of taut bands were significantly lower than those of non-taut bands (all pbands were significantly lower than those at the 1st and 5th stimuli (all pbands than for non-taut bands (both pband itself was more excitable to electrical stimulation and significantly less fatigue resistant than normal muscle fibres.

Electricity market in Croatia according to the new energy laws

International Nuclear Information System (INIS)

Prelec, L.; Tomasic-Skevin, S.; Blagajac, S.; Dokmanovic, B.

2005-01-01

This paper presents laws and regulations related to the electricity market, with emphasis on changes introduced after the package of energy laws had been adopted in 2001. The paper gives an overview of by-laws, which are about to enter into force or are in final preparation stage, creating conditions for eligible customers to change supplier and freely negotiate electricity price. The paper also presents electricity market model in Croatia as well as procedure of supplier change. (author)

Cantilever-based optical interfacial force microscope in liquid using an optical-fiber tip

Directory of Open Access Journals (Sweden)

Byung I. Kim

2013-03-01

Full Text Available We developed a novel cantilever-based optical interfacial force microscope (COIFM to study molecular interaction in liquid environments. The force sensor was created by attaching a chemically etched optical-fiber tip to the force sensor with UV epoxy, and characterized by imaging on a calibration grid. The performance of the COIFM was then demonstrated by measuring the force between two oxidized silicon surfaces in 1 mM KCl as a function of distance. The result was consistent with previously reported electrical double layer forces, suggesting that a COIFM using an optical-fiber tip is capable of measuring force in a liquid environment.

The feasibility of using the 25MW super near boiling nuclear reactor (SNB25) to provide thermal and electrical energy for a large Canadian Forces base in the Canadian Arctic

Energy Technology Data Exchange (ETDEWEB)

Paquette, S.; Bonin, H.W.; Baskin, M.; Bowen, K.; Switzer, Z., E-mail: Stephane.Paquette@rmc.ca [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada)

2014-07-01

A feasibility study of a power plant using the Super Near Boiling 25 MWt (SNB25) nuclear reactor as a heat source and capable of supporting the electrical and thermal requirements for a base the size of Canadian Forces Base (CFB) Kingston in the Arctic was carried out. Such a power plant would allow the Canadian Armed Forces (CAF) to have a self-sustaining operational base in the Arctic to conduct Search and Rescue (SAR) and sovereignty missions. The thermal and electrical requirements for a base the size of CFB Kingston are determined to be 31.63 MWt and 7.16 MWe, respectively. Using the Heating Degree Days (HDD) approach to account for temperature differences between Southern Ontario and the Arctic, a base the size of CFB Kingston in the Arctic would require 75.16 MWt to operate. A chemical engineering software program, UniSim, was used to simulate the energy cycle of the base which consisted of a district heating loop to provide hot water and an Organic Rankine Cycle (ORC) using n-pentane as the working fluid to provide the electrical energy. The UniSim simulations determined that the cycle would use six shell and tube heat exchangers, two axial gas turbines coupled to generators, and twelve centrifugal pumps, in addition to a group of five SNB25 reactors that could provide 25.03 MWt and 2.63 MWe to a base in the Arctic with energy requirements about a third of those of CFB Kingston. The design foresees redundancy which is essential to safe operation in the Arctic. (author)

Dynamic fracture mechanics with electromagnetic force and its application to fracture toughness and testing

International Nuclear Information System (INIS)

Yagawa, G.; Yoshimura, S.

1986-01-01

This study is concerned with the application of the electromagnetic force to the determination of the dynamic fracture toughness of materials. Taken is an edge-cracked specimen which carries a transient electric current I and is simply supported in a uniform and steady magnetic field B. As a result of their interaction, the dynamic electromagnetic force occurs in the whole body of the specimen, which is then deformed to fracture in the opening mode of cracking. For the evaluation of dynamic fracture toughness, the extended J integral with the effects of the electromagnetic force and inertia is calculated using the dynamic finite-element method. To determine the dynamic crack-initiation point in the experiment, the electric potential method is used in the case of brittle fracture, and the electric potential and the J-R curve methods in the case of ductile fracture, respectively. Using these techniques, the dynamic fracture toughness values of nuclear pressure vessel steel A508 class 3 are evaluated over a wide temperature range. (author)

Theoretical Studying the Cyclic Loading of Electric Drive Parts of the Stand duo-160

Directory of Open Access Journals (Sweden)

A. A. Maltsev

2015-01-01

Full Text Available An electric drive of work rolls of the single-stand rolling mill duo-160 located in the laboratory of Bauman Moscow State Technical University (BMSTU is selected as an object of the theoretical study. After the work rolls have gripped the work-piece the torsional vibrations occur in the drive; a 5-mass dynamic model is built to determine their forms and frequencies. Equations of torsionalvibration movement of masses with time are based on the Lagrange equations of type II. The paper identifies intrinsic moments of inertia and angular stiffness of parts and units of the electric drive. The graphs of the moments of elastic forces are built taking into consideration the dampers and backlashes. A revealed transition process has shown that given amplitudes of the cyclic shear stresses arising in dangerous section of the most loaded top spindle do not exceed the limit of its endurance in this section. In case of excess revealed, it would lead to accumulation of fatigue damage in the spindle metal and to formation of fatigue crack that most probably would appear near the shaft surface rather than in the metal mass. With further using the electric drive this micro-crack would be gradually evolved into macro-crack, the working cross-sectional area of the shaft would be reduced so that there would be a spindle failure and on the surface of a fatigue fracture of its shaft a strongly marked crack growth zone and a completely broken zone would be observed.

Asia electricity study

International Nuclear Information System (INIS)

Priddle, R.

1997-01-01

Electricity demand in Asia has grown and continues to grow rapidly. Over 40 per cent of the world's growth in electricity output up to 2010 is expected to come from China and East and South Asia. The need to build the additional production capacity to meet demand is the driving force behind the major structural and institutional changes that are presently transforming the electricity sectors throughout the region. The Asia Electricity Study looks in detail at the current and future role of the electricity sectors in Indonesia, the Philippines and Thailand. It analyses existing and planned electricity policies in areas such as financing regulation, environment and end-use efficiency. To build the region's power infrastructure will require large investments, well beyond what governments or multilateral lending institutions can provide. Consequently, mobilizing private sector participation in the process is vital. Independent Power Producers (IPPs) are being allowed to enter what has, until recently, been a government-dominated field. State-owned utilities are being corporatized and/or privatized to improve their competitiveness. Developing the regulatory environment to match the changes taking place is a key challenge. The significant expansion of generation capacity in Asia will have implications well beyond the region. Changes in energy trade volumes and patterns, caused by the need to obtain fuel for power stations, will have an impact on the energy security of Asia and the world as a whole Similarly, fuel and technology choices will have important consequences for both the regional and global environment. (author)

Analysis of the tractive force pattern on a knot by force measurement during laparoscopic knot tying.

Science.gov (United States)

Takayasu, Kenta; Yoshida, Kenji; Kinoshita, Hidefumi; Yoshimoto, Syunsuke; Oshiro, Osamu; Matsuda, Tadashi

2017-07-19

Quantifying surgical skills assists novice surgeons when learning operative techniques. We measured the interaction force at a ligation point and clarified the features of the force pattern among surgeons with different skill levels during laparoscopic knot tying. Forty-four surgeons were divided into three groups based on experience: 13 novice (0-5 years), 16 intermediate (6-15 years), and 15 expert (16-30 years). To assess the tractive force direction and volume during knot tying, we used a sensor that measures six force-torque values (x-axis: Fx, y-axis: Fy, z-axis: Fz, and xy-axis: Fxy) attached to a slit Penrose drain. All participants completed one double knot and five single knot sequences. We recorded completion time, force volume (FV), maximum force (MF), time over 1.5 N, duration of non-zero force, and percentage time when vertical force exceeded horizontal force (PTz). There was a significant difference between groups for completion time (p = 0.007); FV (total: p = 0.002; Fx: p = 0.004, Fy: p = 0.007, Fxy: p = 0.004, Fz: p force (p = 0.029); and PTz (p force pattern at the ligation point during suturing by surgeons with three levels of experience using a force measurement system. We revealed that both force volume and force direction differed depending on surgeons' skill level during knot tying. Copyright © 2017. Published by Elsevier Inc.

Charge-Spot Model for Electrostatic Forces in Simulation of Fine Particulates

Science.gov (United States)

Walton, Otis R.; Johnson, Scott M.

2010-01-01

The charge-spot technique for modeling the static electric forces acting between charged fine particles entails treating electric charges on individual particles as small sets of discrete point charges, located near their surfaces. This is in contrast to existing models, which assume a single charge per particle. The charge-spot technique more accurately describes the forces, torques, and moments that act on triboelectrically charged particles, especially image-charge forces acting near conducting surfaces. The discrete element method (DEM) simulation uses a truncation range to limit the number of near-neighbor charge spots via a shifted and truncated potential Coulomb interaction. The model can be readily adapted to account for induced dipoles in uncharged particles (and thus dielectrophoretic forces) by allowing two charge spots of opposite signs to be created in response to an external electric field. To account for virtual overlap during contacts, the model can be set to automatically scale down the effective charge in proportion to the amount of virtual overlap of the charge spots. This can be accomplished by mimicking the behavior of two real overlapping spherical charge clouds, or with other approximate forms. The charge-spot method much more closely resembles real non-uniform surface charge distributions that result from tribocharging than simpler approaches, which just assign a single total charge to a particle. With the charge-spot model, a single particle may have a zero net charge, but still have both positive and negative charge spots, which could produce substantial forces on the particle when it is close to other charges, when it is in an external electric field, or when near a conducting surface. Since the charge-spot model can contain any number of charges per particle, can be used with only one or two charge spots per particle for simulating charging from solar wind bombardment, or with several charge spots for simulating triboelectric charging

Effect of electrical field on the quantized vortices in He II

International Nuclear Information System (INIS)

Natsik, V.D.

2007-01-01

Electrical polarization and interaction of quantized vortices with electrical field in superfluid Bose fluid are studied. Two types of the vortices polarization are considered; both of them are caused by action of centrifugal forces upon the fluid atoms at their azimuthal motion around the vortex line. Firstly, atoms obtain dipole moments (internal polarization when external polarization when external field is absent) and a nonuniform symmetrical distribution of the polarization density arises; at that, a vortex has no integral dipole moment but each element of the vortex line bears a quadrupole moment. Secondly, action of the centrifugal forces leads to a nonuniform distribution of the atomic density around the vortex line; therefore, the polarization density of the fluid in the external electrical field is also nonuniform in the vicinity of this line and each isolated element of the vortex line obtains dipole moment proportional to the field magnitude (inductive polarization). Analytical expressions for the polarization density around the straight and circular vortex lines are obtained and the effective dipole and quadrupole moments of the vortices are determined. A distribution of the ponderomotive forces acting on the superfluid fluid with quantized vortices in the external electrical field has been analyzed and the caused by field additives to the energy of the straight and circular vortices are found. Numerical estimations of the effects considered are given for He II

Aspirations and expectations: public views on electricity supply in Ontario, Canada. Paper no. IGEC-1-038

Energy Technology Data Exchange (ETDEWEB)

Rowlands, I.H. [Univ. of Waterloo, Dept. of Environment and Resource Studies, Faculty of Environmental Studies, Waterloo, Ontario (Canada)]. E-mail: irowland@fes.uwaterloo.ca; Parker, P. [Univ. of Waterloo, Dept. of Geography, Faculty of Environmental Studies, Waterloo, Ontario (Canada)]. E-mail: pparker@fes.uwaterloo.ca

2005-07-01

It is increasingly being recognised that electricity is a key public policy issue. No longer the domain of monopoly players shielded from public scrutiny, the growing restructuring of electricity supply systems around the world has increased public involvement in electricity decisions. Accordingly, it is becoming more and more important for policy-makers to have a clear understanding of their citizens' priorities regarding electricity supply issues. This paper examines public attitudes in a major Canadian metropolitan area (Waterloo Region) by analysing the results of over 1,000 surveys on a range of energy and environment issues. Regarding the present arrangements for electricity supply in Ontario, most respondents were not able to identify the resource most used (nuclear power), but instead thought that the resource that has the longest history in the province's electricity system (hydropower) dominated the supply system. Regarding future resource options, while respondents clearly expressed their preference for green electricity, particularly the so-called 'new' renewables (solar and wind power), respondents also felt that the prospects for more traditional resources - particularly, nuclear, hydropower and natural gas - remained higher. Further analyses reveal that two demographic factors (gender and age) and three attitudinal factors (perceived consumer effectiveness, liberalism and ecological concern) help predict those likely to be more optimistic and/or enthusiastic about green electricity. While the empirical material in this paper is taken from the Canadian province of Ontario, key conclusions and broader lessons are more widely applicable. Every community undergoing electricity restructuring of any kind is forced to consider public views to a greater extent. Indeed, prospects for greater use of green electricity in electricity supply systems are contingent upon a greater understanding of citizen views of the same. (author)

Aspirations and expectations: public views on electricity supply in Ontario, Canada. Paper no. IGEC-1-038

International Nuclear Information System (INIS)

Rowlands, I.H.; Parker, P.

2005-01-01

It is increasingly being recognised that electricity is a key public policy issue. No longer the domain of monopoly players shielded from public scrutiny, the growing restructuring of electricity supply systems around the world has increased public involvement in electricity decisions. Accordingly, it is becoming more and more important for policy-makers to have a clear understanding of their citizens' priorities regarding electricity supply issues. This paper examines public attitudes in a major Canadian metropolitan area (Waterloo Region) by analysing the results of over 1,000 surveys on a range of energy and environment issues. Regarding the present arrangements for electricity supply in Ontario, most respondents were not able to identify the resource most used (nuclear power), but instead thought that the resource that has the longest history in the province's electricity system (hydropower) dominated the supply system. Regarding future resource options, while respondents clearly expressed their preference for green electricity, particularly the so-called 'new' renewables (solar and wind power), respondents also felt that the prospects for more traditional resources - particularly, nuclear, hydropower and natural gas - remained higher. Further analyses reveal that two demographic factors (gender and age) and three attitudinal factors (perceived consumer effectiveness, liberalism and ecological concern) help predict those likely to be more optimistic and/or enthusiastic about green electricity. While the empirical material in this paper is taken from the Canadian province of Ontario, key conclusions and broader lessons are more widely applicable. Every community undergoing electricity restructuring of any kind is forced to consider public views to a greater extent. Indeed, prospects for greater use of green electricity in electricity supply systems are contingent upon a greater understanding of citizen views of the same. (author)

Observation of linear I-V curves on vertical GaAs nanowires with atomic force microscope

Science.gov (United States)

Geydt, P.; Alekseev, P. A.; Dunaevskiy, M.; Lähderanta, E.; Haggrén, T.; Kakko, J.-P.; Lipsanen, H.

2015-12-01

In this work we demonstrate the possibility of studying the current-voltage characteristics for single vertically standing semiconductor nanowires on standard AFM equipped by current measuring module in PeakForce Tapping mode. On the basis of research of eight different samples of p-doped GaAs nanowires grown on different GaAs substrates, peculiar electrical effects were revealed. It was found how covering of substrate surface by SiOx layer increases the current, as well as phosphorous passivation of the grown nanowires. Elimination of the Schottky barrier between golden cap and the top parts of nanowires was observed. It was additionally studied that charge accumulation on the shell of single nanowires affects its resistivity and causes the hysteresis loops on I-V curves.

Effects of Constant and Doublet Frequency Electrical Stimulation Patterns on Force Production of Knee Extensor Muscles.

Directory of Open Access Journals (Sweden)

Carole Cometti

Full Text Available This study compared knee extensors' neuromuscular fatigue in response to two 30-minute stimulation patterns: constant frequency train (CFT and doublet frequency train (DFT. Fifteen men underwent two separate sessions corresponding to each pattern. Measurements included torque evoked by each contraction and maximal voluntary contractions (MVC measured before and immediately after the stimulation sessions. In addition, activation level and torque evoked during doublets (Pd and tetanic contractions at 80-Hz (P80 and 20-Hz (P20 were determined in six subjects. Results indicated greater mean torque during the DFT stimulation session as compared with CFT. But, no difference was obtained between the two stimulation patterns for MVC and evoked torque decreases. Measurements conducted in the subgroup depicted a significant reduction of Pd, P20 and P80. Statistical analyses also revealed bigger P20 immediate reductions after CFT than after DFT. We concluded that DFT could be a useful stimulation pattern to produce and maintain greater force with quite similar fatigue than CFT.

High current capacity electrical connector

International Nuclear Information System (INIS)

Bettis, E.S.; Watts, H.L.

1976-01-01

An electrical connector is provided for coupling high current capacity electrical conductors such as copper busses or the like. The connector is arranged in a ''sandwiched'' configuration in which a conductor plate contacts the busses along major surfaces clamped between two stainless steel backing plates. The conductor plate is provided with contact buttons in a spaced array such that the caps of the buttons extend above the conductor plate surface to contact the busses. When clamping bolts provided through openings in the sandwiched arrangement are tightened, Belleville springs provided under the rim of each button cap are compressed and resiliently force the caps into contact with the busses' contacting surfaces to maintain a predetermined electrical contact area provided by the button cap tops. The contact area does not change with changing thermal or mechanical stresses applied to the coupled conductors

Workspace Safe Operation of a Force- or Impedance-Controlled Robot

Science.gov (United States)

Abdallah, Muhammad E. (Inventor); Hargrave, Brian (Inventor); Yamokoski, John D. (Inventor); Strawser, Philip A. (Inventor)

2013-01-01

A method of controlling a robotic manipulator of a force- or impedance-controlled robot within an unstructured workspace includes imposing a saturation limit on a static force applied by the manipulator to its surrounding environment, and may include determining a contact force between the manipulator and an object in the unstructured workspace, and executing a dynamic reflex when the contact force exceeds a threshold to thereby alleviate an inertial impulse not addressed by the saturation limited static force. The method may include calculating a required reflex torque to be imparted by a joint actuator to a robotic joint. A robotic system includes a robotic manipulator having an unstructured workspace and a controller that is electrically connected to the manipulator, and which controls the manipulator using force- or impedance-based commands. The controller, which is also disclosed herein, automatically imposes the saturation limit and may execute the dynamic reflex noted above.

Continuous theta-burst stimulation to primary motor cortex reveals asymmetric compensation for sensory attenuation in bimanual repetitive force production.

Science.gov (United States)

Therrien, Amanda S; Lyons, James; Balasubramaniam, Ramesh

2013-08-01

Studies of fingertip force production have shown that self-produced forces are perceived as weaker than externally generated forces. This is due to mechanisms of sensory reafference where the comparison between predicted and actual sensory feedback results in attenuated perceptions of self-generated forces. Without an external reference to calibrate attenuated performance judgments, a compensatory overproduction of force is exhibited. It remains unclear whether the force overproduction seen in the absence of visual reference stimuli differs when forces are produced bimanually. We studied performance of two versions of a bimanual sequential force production task compared with each hand performing the task unimanually. When the task goal was shared, force series produced by each hand in bimanual conditions were found to be uncorrelated. When the bimanual task required each hand to reach a target force level, we found asymmetries in the degree of force overproduction between the hands following visual feedback removal. Unilateral continuous theta-burst stimulation of the left primary motor cortex yielded a selective reduction of force overproduction in the hand contralateral to stimulation by disrupting sensory reafference processes. While variability was lower in bimanual trials when the task goal was shared, this influence of hand condition disappeared when the target force level was to be reached by each hand simultaneously. Our findings strengthen the notion that force control in bimanual action is less tightly coupled than other mechanisms of bimanual motor control and show that this effector specificity may be extended to the processing and compensation for mechanisms of sensory reafference.

Effect of radial electric field inhomogeneity on anomalous cross field plasma flux in Heliotron/Torsatron

International Nuclear Information System (INIS)

Yamagishi, Tomejiro; Sanuki, Heiji.

1996-01-01

Anomalous cross field plasma fluxes induced by the electric field fluctuations has been evaluated in a rotating plasma with shear flow in a helical system. The anomalous ion flux is evaluated by the contribution from ion curvature drift resonance continuum in the test particle model. The radial electric field induces the Doppler frequency shift which disappears in the frequency integrated anomalous flux. The inhomogeneity of the electric field (shear flow effect), however, induces a new force term in the flux. The curvature drift resonance also induces a new force term '/ which, however, did not make large influence in the ion flux in the CHS configuration. The shear flow term in the flux combined with the electric field in neoclassical flux reduces to a first order differential equation which governs the radial profile of the electric field. Numerical results indicate that the shear flow effect is important for the anomalous cross field flux and for determination of the radial electric field particularly in the peripheral region. (author)

Artifact-free dynamic atomic force microscopy reveals monotonic dissipation for a simple confined liquid

Science.gov (United States)

Kaggwa, G. B.; Kilpatrick, J. I.; Sader, J. E.; Jarvis, S. P.

2008-07-01

We present definitive interaction measurements of a simple confined liquid (octamethylcyclotetrasiloxane) using artifact-free frequency modulation atomic force microscopy. We use existing theory to decouple the conservative and dissipative components of the interaction, for a known phase offset from resonance (90° phase shift), that has been deliberately introduced into the experiment. Further we show the qualitative influence on the conservative and dissipative components of the interaction of a phase error deliberately introduced into the measurement, highlighting that artifacts, such as oscillatory dissipation, can be readily observed when the phase error is not compensated for in the force analysis.

On Noether symmetries and form invariance of mechanico-electrical systems

International Nuclear Information System (INIS)

Fu Jingli; Chen Liqun

2004-01-01

This Letter focuses on form invariance and Noether symmetries of mechanico-electrical systems. Based on the invariance of Hamiltonian actions for mechanico-electrical systems under the infinitesimal transformation of the coordinates, the electric quantities and the time, the authors present the Noether symmetry transformation, the Noether quasi-symmetry transformation, the generalized Noether quasi-symmetry transformation and the general Killing equations of Lagrange mechanico-electrical systems and Lagrange-Maxwell mechanico-electrical systems. Using the invariance of the differential equations, satisfied by physical quantities, such as Lagrangian, non-potential general forces, under the infinitesimal transformation, the authors propose the definition and criterions of the form invariance for mechanico-electrical systems. The Letter also demonstrates connection between the Noether symmetries and the form invariance of mechanico-electrical systems. An example is designed to illustrate these results

Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Fukuma, Takeshi [Frontier Science Organization, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Mostaert, Anika S; Jarvis, Suzanne P [Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Republic of Ireland (Ireland); Serpell, Louise C [Department of Biochemistry, University of Sussex, John Maynard Building, Falmer BN1 9QG (United Kingdom)], E-mail: fukuma@staff.kanazawa-u.ac.jp, E-mail: Anika.Mostaert@ucd.ie, E-mail: L.C.Serpell@sussex.ac.uk, E-mail: Suzi.Jarvis@ucd.ie

2008-09-24

We have investigated the surface structure of islet amyloid polypeptide (IAPP) fibrils and {alpha}-synuclein protofibrils in liquid by means of frequency modulation atomic force microscopy (FM-AFM). Angstroem-resolution FM-AFM imaging of isolated macromolecules in liquid is demonstrated for the first time. Individual {beta}-strands aligned perpendicular to the fibril axis with a spacing of 0.5 nm are resolved in FM-AFM images, which confirms cross-{beta} structure of IAPP fibrils in real space. FM-AFM images also reveal the existence of 4 nm periodic domains along the axis of IAPP fibrils. Stripe features with 0.5 nm spacing are also found in images of {alpha}-synuclein protofibrils. However, in contrast to the case for IAPP fibrils, the stripes are oriented 30 deg. from the axis, suggesting the possibility of {beta}-strand alignment in protofibrils different from that in mature fibrils or the regular arrangement of thioflavin T molecules present during the fibril preparation aligned at the surface of the protofibrils.

Revealing molecular-level surface structure of amyloid fibrils in liquid by means of frequency modulation atomic force microscopy

International Nuclear Information System (INIS)

Fukuma, Takeshi; Mostaert, Anika S; Jarvis, Suzanne P; Serpell, Louise C

2008-01-01

We have investigated the surface structure of islet amyloid polypeptide (IAPP) fibrils and α-synuclein protofibrils in liquid by means of frequency modulation atomic force microscopy (FM-AFM). Angstroem-resolution FM-AFM imaging of isolated macromolecules in liquid is demonstrated for the first time. Individual β-strands aligned perpendicular to the fibril axis with a spacing of 0.5 nm are resolved in FM-AFM images, which confirms cross-β structure of IAPP fibrils in real space. FM-AFM images also reveal the existence of 4 nm periodic domains along the axis of IAPP fibrils. Stripe features with 0.5 nm spacing are also found in images of α-synuclein protofibrils. However, in contrast to the case for IAPP fibrils, the stripes are oriented 30 deg. from the axis, suggesting the possibility of β-strand alignment in protofibrils different from that in mature fibrils or the regular arrangement of thioflavin T molecules present during the fibril preparation aligned at the surface of the protofibrils

Fabrication of high-aspect-ratio microstructures using dielectrophoresis-electrocapillary force-driven UV-imprinting

International Nuclear Information System (INIS)

Li, Xiangming; Shao, Jinyou; Tian, Hongmiao; Ding, Yucheng; Li, Xiangmeng

2011-01-01

We propose a novel method for fabricating high-aspect-ratio micro-/nano-structures by dielectrophoresis-electrocapillary force (DEP-ECF)-driven UV-imprinting. The force of DEP-ECF, acting on an air–liquid interface and an air–liquid–solid three-phase contact line, is generated by applying voltage between an electrically conductive mold and a substrate, and tends to pull the dielectric liquid (a UV-curable pre-polymer) into the mold micro-cavities. The existence of DEP-ECF is explained theoretically and demonstrated experimentally by the electrically induced reduction of the contact angle. Furthermore, DEP-ECF is proven to play a critical role in forcing the polymer to fill into the mold cavities by the real-time observation of the dynamic filling process. Using the DEP-ECF-driven UV-imprinting process, high-aspect-ratio polymer micro-/nano-structures (more than 10:1) are fabricated with high consistency. This patterning method can overcome the drawbacks of the mechanically induced mold deformation and position shift in conventional imprinting lithography and maximize the pattern uniformity which is usually poor in capillary force lithography

U. S. Naval Forces, Vietnam Monthly Historical Supplement for March 1968

Science.gov (United States)

1968-08-29

2> - ~ CONFIDENTIAL 62 . . . . . . . . .. . . . . 0 CONFIDENTIAL north of the Mekong River. The concept of the operation called for the 3/60th...Ranh Bay, the two admirals were also briefed on MARKET TIME concepts and operations at the Coastal Surveillance Force headquarters. CONFIDN’TITS 6...but unexploded round in - chamber) 1 C-4 plastique , cases 20 Electrical blasting caps, type 4 200 Electrical blasting cape, type 3 200 Soviet blasting

Atomic force microscopy and nanoindentation investigation of polydimethylsiloxane elastomeric substrate compliancy for various sputtered thin film morphologies.

Science.gov (United States)

Maji, Debashis; Das, Soumen

2018-03-01

Crack free electrically continuous metal thin films over soft elastomeric substrates play an integral part in realization of modern day flexible bioelectronics and biosensors. Under nonoptimized deposition conditions, delamination, and/or cracking of the top film as well as the underlying soft substrate hinders optimal performance of these devices. Hence it is very important to understand and control not only the various deposition factors like power, time, or deposition pressure but also investigate the various interfacial physics playing a critical role in assuring thin film adhesion and substrate compliancy. In the present study, various nanomechanical information of the underlying substrate, namely, crack profile, average roughness, Young's modulus, and adhesion force were studied for uncracked and cracked polydimethylsiloxane (PDMS) surfaces along with pristine and conventional plasma treated PDMS samples as control. Quantification of the above parameters were done using three-dimensional surface profiler, scanning electron microscopy, nanoindentation, and atomic force microscopy techniques to elucidate the modulus range, average roughness, and adhesion force. Comparative analysis with control revealed remarkable similarity between increased modulus values, increased surface roughness, and reduced adhesion force accounting for reduced substrate compliancy and resulting in film cracking or buckling which are critical for development of various bioflexible devices. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 725-737, 2018. © 2017 Wiley Periodicals, Inc.

Electricity Generation Characteristics of Energy-Harvesting System with Piezoelectric Element Using Mechanical-Acoustic Coupling

Directory of Open Access Journals (Sweden)

Hirotarou Tsuchiya

2016-01-01

Full Text Available This paper describes the electricity generation characteristics of a new energy-harvesting system with piezoelectric elements. The proposed system is composed of a rigid cylinder and thin plates at both ends. The piezoelectric elements are installed at the centers of both plates, and one side of each plate is subjected to a harmonic point force. In this system, vibration energy is converted into electrical energy via electromechanical coupling between the plate vibration and piezoelectric effect. In addition, the plate vibration excited by the point force induces a self-sustained vibration at the other plate via mechanical-acoustic coupling between the plate vibrations and an internal sound field into the cylindrical enclosure. Therefore, the electricity generation characteristics should be considered as an electromechanical-acoustic coupling problem. The characteristics are estimated theoretically and experimentally from the electric power in the electricity generation, the mechanical power supplied to the plate, and the electricity generation efficiency that is derived from the ratio of both power. In particular, the electricity generation efficiency is one of the most appropriate factors to evaluate a performance of electricity generation systems. Thus, the effect of mechanical-acoustic coupling is principally evaluated by examining the electricity generation efficiency.

Vibration Prediction Method of Electric Machines by using Experimental Transfer Function and Magnetostatic Finite Element Analysis

International Nuclear Information System (INIS)

Saito, A; Kuroishi, M; Nakai, H

2016-01-01

This paper concerns the noise and structural vibration caused by rotating electric machines. Special attention is given to the magnetic-force induced vibration response of interior-permanent magnet machines. In general, to accurately predict and control the vibration response caused by the electric machines, it is inevitable to model not only the magnetic force induced by the fluctuation of magnetic fields, but also the structural dynamic characteristics of the electric machines and surrounding structural components. However, due to complicated boundary conditions and material properties of the components, such as laminated magnetic cores and varnished windings, it has been a challenge to compute accurate vibration response caused by the electric machines even after their physical models are available. In this paper, we propose a highly-accurate vibration prediction method that couples experimentally-obtained discrete structural transfer functions and numerically-obtained distributed magnetic-forces. The proposed vibration synthesis methodology has been applied to predict vibration responses of an interior permanent magnet machine. The results show that the predicted vibration response of the electric machine agrees very well with the measured vibration response for several load conditions, for wide frequency ranges. (paper)

A General Overview of Electric Road Vehicles

International Nuclear Information System (INIS)

Lamblin, Veronique

2018-01-01

In July 2017 Nicolas Hulot, the French Minister of Ecological and Inclusive Transition, presented a climate plan featuring an end to electricity generation from coal by 2022, a reduction in the nuclear component of electricity supply by one third, a total ban on the sale of petrol or diesel cars by 2040 and an incentive scheme designed gradually to remove polluting vehicles from the roads. Other European partners are following suit and promoting the spread of electric vehicles (Norway, Germany, Netherlands etc.). Yet is this the panacea that will meet the targets for greenhouse gas reduction in the battle against climate change? Futuribles examines the question in this issue with two articles: the first of these by Pierre Bonnaure, above, assesses the forces driving the spread of electric cars and the impediments to that process; this second article by Veronique Lamblin offers a general over - view of electric road vehicles (passenger cars, heavy good vehicles, bicycles etc.) throughout the world. (author)

Electric Currents along Astrophysical Jets

Directory of Open Access Journals (Sweden)

Ioannis Contopoulos

2017-10-01

Full Text Available Astrophysical black holes and their surrounding accretion disks are believed to be threaded by grand design helical magnetic fields. There is strong theoretical evidence that the main driver of their winds and jets is the Lorentz force generated by these fields and their associated electric currents. Several researchers have reported direct evidence for large scale electric currents along astrophysical jets. Quite unexpectedly, their directions are not random as would have been the case if the magnetic field were generated by a magnetohydrodynamic dynamo. Instead, in all kpc-scale detections, the inferred electric currents are found to flow away from the galactic nucleus. This unexpected break of symmetry suggests that a battery mechanism is operating around the central black hole. In the present article, we summarize observational evidence for the existence of large scale electric currents and their associated grand design helical magnetic fields in kpc-scale astrophysical jets. We also present recent results of general relativistic radiation magnetohydrodynamic simulations which show the action of the Cosmic Battery in the vicinity of astrophysical black holes.

Electricity and the Canadian economy

International Nuclear Information System (INIS)

Melvin, J.G.

1981-10-01

Electricity consumption in Canada bore a fixed relationship to real Gross National Product (GNP) throughout the period 1961 to 1979, with an annual growth rate equal to 1.275 times GNP growth rate. Data for the Province of Ontario reveal a similar correlation, but suggest an accelerated demand relative to Gross Provincial Product since 1973, perhaps due to cost-induced substitution of electricity for oil. Electricity demand growth and economic expansion are seen to be mutually reinforcing. High and low values are estimated for future growth rates of population and per-capita GNP. Combined with appropriate rates of oil substitution, these yield projections of electricity demand growth to the end of the century. Electricity demand is likely to grow at close to the traditional rate of 7% per annum unless economic stagnation continues, population growth is minimal, and electricity fails to substitute for oil on a significant scale

Silicon Nano fabrication by Atomic Force Microscopy-Based Mechanical Processing

International Nuclear Information System (INIS)

Miyake, Sh.; Wang, M.; Kim, J.

2014-01-01

This paper reviews silicon nano fabrication processes using atomic force microscopy (AFM). In particular, it summarizes recent results obtained in our research group regarding AFM-based silicon nano fabrication through mechanochemical local oxidation by diamond tip sliding, as well as mechanical, electrical, and electromechanical processing using an electrically conductive diamond tip. Microscopic three-dimensional manufacturing mainly relies on etching, deposition, and lithography. Therefore, a special emphasis was placed on nano mechanical processes, mechanochemical reaction by potassium hydroxide solution etching, and mechanical and electrical approaches. Several important surface characterization techniques consisting of scanning tunneling microscopy and related techniques, such as scanning probe microscopy and AFM, were also discussed.

Nanostructure and force spectroscopy analysis of human peripheral blood CD4+ T cells using atomic force microscopy

International Nuclear Information System (INIS)

Hu Mingqian; Wang Jiongkun; Cai Jiye; Wu Yangzhe; Wang Xiaoping

2008-01-01

To date, nanoscale imaging of the morphological changes and adhesion force of CD4 + T cells during in vitro activation remains largely unreported. In this study, we used atomic force microscopy (AFM) to study the morphological changes and specific binding forces in resting and activated human peripheral blood CD4 + T cells. The AFM images revealed that the volume of activated CD4 + T cells increased and the ultrastructure of these cells also became complex. Using a functionalized AFM tip, the strength of the specific binding force of the CD4 antigen-antibody interaction was found to be approximately three times that of the unspecific force. The adhesion forces were not randomly distributed over the surface of a single activated CD4 + T cell, indicated that the CD4 molecules concentrated into nanodomains. The magnitude of the adhesion force of the CD4 antigen-antibody interaction did not change markedly with the activation time. Multiple bonds involved in the CD4 antigen-antibody interaction were measured at different activation times. These results suggest that the adhesion force involved in the CD4 antigen-antibody interaction is highly selective and of high affinity

Nanostructure and force spectroscopy analysis of human peripheral blood CD4+ T cells using atomic force microscopy.

Science.gov (United States)

Hu, Mingqian; Wang, Jiongkun; Cai, Jiye; Wu, Yangzhe; Wang, Xiaoping

2008-09-12

To date, nanoscale imaging of the morphological changes and adhesion force of CD4(+) T cells during in vitro activation remains largely unreported. In this study, we used atomic force microscopy (AFM) to study the morphological changes and specific binding forces in resting and activated human peripheral blood CD4(+) T cells. The AFM images revealed that the volume of activated CD4(+) T cells increased and the ultrastructure of these cells also became complex. Using a functionalized AFM tip, the strength of the specific binding force of the CD4 antigen-antibody interaction was found to be approximately three times that of the unspecific force. The adhesion forces were not randomly distributed over the surface of a single activated CD4(+) T cell, indicated that the CD4 molecules concentrated into nanodomains. The magnitude of the adhesion force of the CD4 antigen-antibody interaction did not change markedly with the activation time. Multiple bonds involved in the CD4 antigen-antibody interaction were measured at different activation times. These results suggest that the adhesion force involved in the CD4 antigen-antibody interaction is highly selective and of high affinity.

Canada's first competitive electricity market: the Alberta experience

International Nuclear Information System (INIS)

McMaster, D.

1997-01-01

The restructuring of the electric power industry as experienced in the province of Alberta was discussed. Alberta's electric industry structure today is comprised of a power pool and open access transmission. The forces for change, the evolution of the new structure, the new Electric Utilities Act that defined restructuring, features of the restructured industry, the organization and functions of the Alberta Power Pool and the Transmission Administrator, the day-to-day functioning of the Power Pool, the price setting mechanism, access to the transmission system, the legislated financial hedges, the timeline for the retirement of the existing generation system, and anticipated future developments were described

Effects of High-Latitude Forcing Uncertainty on the Low-Latitude and Midlatitude Ionosphere

Science.gov (United States)

Pedatella, N. M.; Lu, G.; Richmond, A. D.

2018-01-01

Ensemble simulations are performed using the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM) in order to understand the role of high-latitude forcing uncertainty on the low-latitude and midlatitude ionosphere response to the April 2010 geomagnetic storm. The ensemble is generated by perturbing either the high-latitude electric potential or auroral energy flux in the assimilative mapping for ionosphere electrodynamics (AMIE). Simulations with perturbed high-latitude electric potential result in substantial intraensemble variability in the low-latitude and midlatitude ionosphere response to the geomagnetic storm, and the ensemble standard deviation for the change in NmF2 reaches 50-100% of the mean change. Such large intraensemble variability is not seen when perturbing the auroral energy flux. In this case, the effects of the forcing uncertainty are primarily confined to high latitudes. We therefore conclude that the specification of high-latitude electric fields is an important source of uncertainty when modeling the low-latitude and midlatitude ionosphere response to a geomagnetic storm. A multiple linear regression analysis of the results indicates that uncertainty in the storm time changes in the equatorial electric fields, neutral winds, and neutral composition can all contribute to the uncertainty in the ionosphere electron density. The results of the present study provide insight into the possible uncertainty in simulations of the low-latitude and midlatitude ionosphere response to geomagnetic storms due to imperfect knowledge of the high-latitude forcing.

THE ANALISYS OF RAILWAY MULTI MOTORS ELECTRICAL DRIVE DYNAMIC

Directory of Open Access Journals (Sweden)

V. I. Khilmon

2015-01-01

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

Localization and force analysis at the single virus particle level using atomic force microscopy

International Nuclear Information System (INIS)

Liu, Chih-Hao; Horng, Jim-Tong; Chang, Jeng-Shian; Hsieh, Chung-Fan; Tseng, You-Chen; Lin, Shiming

2012-01-01

Highlights: ► Localization of single virus particle. ► Force measurements. ► Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

Quantum degeneracy in atomic point contacts revealed by chemical force and conductance

Czech Academy of Sciences Publication Activity Database

Sugimoto, Y.; Ondráček, Martin; Abe, M.; Pou, P.; Morita, S.; Perez, R.; Flores, F.; Jelínek, Pavel

2013-01-01

Roč. 111, č. 10 (2013), "106803-1"-"106803-5" ISSN 0031-9007 R&D Projects: GA ČR(CZ) GPP204/11/P578 Grant - others:GA AV ČR(CZ) M100101207 Institutional support: RVO:68378271 Keywords : scanning tunneling microscopy * atomic force microscopy * degenerate states * silicon surface * dangling bonds Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.728, year: 2013

Distributed force simulation for arbitrarily shaped IPMC actuators

International Nuclear Information System (INIS)

Martinez, M; Lumia, R

2013-01-01

This paper presents a simulation model that predicts the force output of arbitrarily shaped ionic polymer–metal composite (IPMC) actuators. Theoretical and experimental force measurements are compared for a triangular IPMC actuator with a tip length of 11 mm. The results show that the simulated tip force is within 80% of the experimentally determined value. Simulated electrical results for an artificial shark pectoral fin and a 7 mm × 17 mm actuator are also presented. In each case, the voltage is shown to decrease exponentially from the input point. The results of an ion migration simulation for a 180 μm cubic element of Nafion are presented for both a constant 2 V input and a 2 V 0.25 Hz sine signal. Finally, the simulated deformation of an IPMC shark fin is shown. (paper)

Forces and energy dissipation in inhomogeneous non-equilibrium superconductors

International Nuclear Information System (INIS)

Poluehktov, Yu.M.; Slezov, V.V.

1987-01-01

The phenomenological theory of volume forces and dissipation processes in inhomogeneous non-equilibrium superconductors near temperature transition from the normal to superconducting state is constructed. The approach is based on application of dynamic equations of superconductivity formulated on the basis of the Lagrangian formalism. These equations are generalized the Ginzburg-Landau theory in the nonstationary non-equilibrium case for ''foul'' superconductors. The value estimations of volume forces arising in inhomogeneities during relaxation of an order parameter and when the electrical field is penetrated into the superconductor, are given

Interfacial forces in aqueous media

CERN Document Server

van Oss, Carel J

2006-01-01

Thoroughly revised and reorganized, the second edition of Interfacial Forces in Aqueous Media examines the role of polar interfacial and noncovalent interactions among biological and nonbiological macromolecules as well as biopolymers, particles, surfaces, cells, and both polar and apolar polymers. The book encompasses Lifshitz-van der Waals and electrical double layer interactions, as well as Lewis acid-base interactions between colloidal entities in polar liquids such as water. New in this Edition: Four previously unpublished chapters comprising a new section on interfacial propertie

Modeling and boundary force control of microcantilevers utilized in atomic force microscopy for cellular imaging and characterization

Science.gov (United States)

Eslami, Sohrab

This dissertation undertakes the theoretical and experimental developments microcantilevers utilized in Atomic Force Microscopy (AFM) with applications to cellular imaging and characterization. The capability of revealing the inhomogeneties or interior of ultra-small materials has been of most interest to many researchers. However, the fundamental concept of signal and image formation remains unexplored and not fully understood. For his, a semi-empirical nonlinear force model is proposed to show that virtual frequency generation, regarded as the simplest synthesized subsurface probe, occurs optimally when the force is tuned to the van der Waals form. This is the first-time observation of a novel theoretical dynamic multi-frequency force microscopy that has not been already reported. Owing to the broad applications of microcantilevers in the nanoscale imaging and microscopic techniques, there is an essential feeling to study and propose a comprehensive model of such systems. Therefore, in the theoretical part of this dissertation, a distributed-parameters representation modeling of the microcantilever along with a general interaction force comprising of two attractive and repulsive components with general amplitude and power terms is studied. This model is investigated in a general 2D Cartesian coordinate to consider the motions of the probe with a tip mass. There is an excitation at the microcantilever's base such that the end of the beam is subject to the proposed general force. These forces are very sensitive to the amplitude and power terms of these parts; on the other hand, atomic intermolecular force is a function of the distance such that this distance itself is also a function of the interaction force that will result in a nonlinear implicit equation. From a parametric study in the probe-sample excitation, it is shown that the predicted behavior of the generated difference-frequency oscillation amplitude agrees well with experimental measurements. Following

Study on electrical defects level in single layer two-dimensional Ta2O5

Science.gov (United States)

Dahai, Li; Xiongfei, Song; Linfeng, Hu; Ziyi, Wang; Rongjun, Zhang; Liangyao, Chen; David, Wei Zhang; Peng, Zhou

2016-04-01

Two-dimensional atomic-layered material is a recent research focus, and single layer Ta2O5 used as gate dielectric in field-effect transistors is obtained via assemblies of Ta2O5 nanosheets. However, the electrical performance is seriously affected by electronic defects existing in Ta2O5. Therefore, spectroscopic ellipsometry is used to calculate the transition energies and corresponding probabilities for two different charged oxygen vacancies, whose existence is revealed by x-ray photoelectron spectroscopy analysis. Spectroscopic ellipsometry fitting also calculates the thickness of single layer Ta2O5, exhibiting good agreement with atomic force microscopy measurement. Nondestructive and noncontact spectroscopic ellipsometry is appropriate for detecting the electrical defects level of single layer Ta2O5. Project supported by the National Natural Science Foundation of China (Grant Nos. 11174058 and 61376093), the Fund from Shanghai Municipal Science and Technology Commission (Grant No. 13QA1400400), the National Science and Technology Major Project, China (Grant No. 2011ZX02707), and the Innovation Program of Shanghai Municipal Education Commission (Grant No. 12ZZ010).

Shape-dependent orientation of thermophoretic forces in microsystems

KAUST Repository

Li, Qi

2013-09-24

It is generally acknowledged that the direction of the thermophoretic force acting on microparticles is largely determined by the imposed temperature gradient, and the shape of the microparticle has little influence on its direction. We show that one type of thermophoretic force, emerged due to the advent of microfabrication techniques, is highly sensitive to object shape, and it is feasible to tune force orientation via proper shape design. We reveal the underlying mechanism by an asymptotic analysis of the Boltzmann equation and point out the reason why the classical thermophoretic force is insensitive to the particle shape, but the force in microsystems is. The discovered phenomenon could find its applications in methods for microparticle manipulation and separation.

Shape-dependent orientation of thermophoretic forces in microsystems

KAUST Repository

Li, Qi; Liang, Tengfei; Ye, Wenjing

2013-01-01

It is generally acknowledged that the direction of the thermophoretic force acting on microparticles is largely determined by the imposed temperature gradient, and the shape of the microparticle has little influence on its direction. We show that one type of thermophoretic force, emerged due to the advent of microfabrication techniques, is highly sensitive to object shape, and it is feasible to tune force orientation via proper shape design. We reveal the underlying mechanism by an asymptotic analysis of the Boltzmann equation and point out the reason why the classical thermophoretic force is insensitive to the particle shape, but the force in microsystems is. The discovered phenomenon could find its applications in methods for microparticle manipulation and separation.

Sprag solenoid brake. [development and operations of electrically controlled brake

Science.gov (United States)

Dane, D. H. (Inventor)

1974-01-01

The development and characteristics of an electrically operated brake are discussed. The action of the brake depends on energizing a solenoid which causes internally spaced sprockets to contact the inner surface of the housing. A spring forces the control member to move to the braking position when the electrical function is interrupted. A diagram of the device is provided and detailed operating principles are explained.

Structural, chemical and electrical characterisation of conductive graphene-polymer composite films

Energy Technology Data Exchange (ETDEWEB)

Brennan, Barry; Spencer, Steve J.; Belsey, Natalie A. [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom); Faris, Tsegie [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Cronin, Harry [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Advanced Technology Institute (ATI), University of Surrey, Guildford, GU2 7XH (United Kingdom); Silva, S. Ravi P. [Advanced Technology Institute (ATI), University of Surrey, Guildford, GU2 7XH (United Kingdom); Sainsbury, Toby; Gilmore, Ian S. [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom); Stoeva, Zlatka [DZP Technologies Ltd., Future Business Centre, Cambridge, CB4 2HY (United Kingdom); Pollard, Andrew J., E-mail: andrew.pollard@npl.co.uk [National Physical Laboratory, Teddington, TW11 0LW (United Kingdom)

2017-05-01

Graphical abstract: Secondary Ion Mass Spectrometry (SIMS) imaging of the dispersion of graphene within graphene-polymer composites using the Na{sup +} signal. - Highlights: • Relation of properties of graphene flakes with electrical properties of composite. • Standardised characterisation method for structural properties of graphene flakes. • Structural and chemical characterisation of commercial graphene flakes. • ToF-SIMS used to determine dispersion of graphene in polymer. - Abstract: Graphene poly-acrylic and PEDOT:PSS nanocomposite films were produced using two alternative commercial graphene powders to explore how the graphene flake dimensions and chemical composition affected the electrical performance of the film. A range of analytical techniques, including scanning electron microscopy (SEM), atomic force microscopy (AFM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS), were employed to systematically analyse the initial graphene materials as well as the nanocomposite films. Electrical measurements indicated that the sheet resistance of the films was affected by the properties of the graphene flakes used. To further explore the composition of the films, ToF-SIMS mapping was employed and provided a direct means to elucidate the nature of the graphene dispersion in the films and to correlate this with the electrical analysis. These results reveal important implications for how the dispersion of the graphene material in films produced from printable inks can be affected by the type of graphene powder used and the corresponding effect on electrical performance of the nanocomposites. This work provides direct evidence for how accurate and comparable characterisation of the graphene material is required for real-world graphene materials to develop graphene enabled films and proposes a measurement protocol for comparing graphene materials that can be used for international

Transition from steady to periodic liquid-metal magnetohydrodynamic flow in a sliding electrical contact

Science.gov (United States)

Talmage, Gita; Walker, John S.; Brown, Samuel H.; Sondergaard, Neal A.

1993-09-01

In homopolar motors and generators, large dc electric currents pass through the sliding electrical contacts between rotating copper disks (rotors) and static copper surfaces shrouding the rotor tips (stators). A liquid metal in the small radial gap between the rotor tip and concentric stator surface can provide a low-resistance, low-drag electrical contact. Since there is a strong magnetic field in the region of the electrical contacts, there are large electromagnetic body forces on the liquid metal. The primary, azimuthal motion consists of simple Couette flow, plus an electromagnetically driven flow with large extremes of the azimuthal velocity near the rotor corners. The secondary flow involves the radial and axial velocity components, is driven by the centrifugal force associated with the primary flow, and is opposed by the electromagnetic body force, so that the circulation varies inversely as the square of the magnetic-field strength. Three flow regimes are identified as the angular velocity Ω of the rotor is increased. For small Ω, the primary flow is decoupled from the secondary flow. As Ω increases, the secondary flow begins to convect the azimuthal-velocity peaks radially outward, which in turn changes the centrifugal force driving the secondary flow. At some critical value of Ω, the flow becomes periodic through the coupling of the primary and secondary flows. The azimuthal-velocity peaks begin to move radially in and out with an accompanying oscillation in the secondary-flow strength.

Electrical Stimulation of Artificial Heart Muscle: a look into the electrophysiological and genetic implications

Science.gov (United States)

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

2016-01-01

Development of tissue-engineered hearts for treatment of myocardial infarction or biological pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. In order to further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histological observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHM. Improvements in electrophysiology within the AHM was noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHM. Genes expressing key electrophysiological and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHM capable of replacing damaged heart tissue in either a contractile or electrophysiological capacity. Optimized AHM can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis. PMID:28459744

Electrical Stimulation of Artificial Heart Muscle: A Look Into the Electrophysiologic and Genetic Implications.

Science.gov (United States)

Mohamed, Mohamed A; Islas, Jose F; Schwartz, Robert J; Birla, Ravi K

Development of tissue-engineered hearts for treatment of myocardial infarction or biologic pacemakers has been hindered by the production of mostly arrhythmic or in-synergistic constructs. Electrical stimulation (ES) of these constructs has been shown to produce tissues with greater twitch force and better adrenergic response. To further our understanding of the mechanisms underlying the effect of ES, we fabricated a bioreactor capable of delivering continuous or intermittent waveforms of various types to multiple constructs simultaneously. In this study, we examined the effect of an intermittent biphasic square wave on our artificial heart muscle (AHM) composed of neonatal rat cardiac cells and fibrin gel. Twitch forces, spontaneous contraction rates, biopotentials, gene expression profiles, and histologic observations were examined for the ES protocol over a 12 day culture period. We demonstrate improved consistency between samples for twitch force and contraction rate, and higher normalized twitch force amplitudes for electrically stimulated AHMs. Improvements in electrophysiology within the AHM were noted by higher conduction velocities and lower latency in electrical response for electrically stimulated AHMs. Genes expressing key electrophysiologic and structural markers peaked at days 6 and 8 of culture, only a few days after the initiation of ES. These results may be used for optimization strategies to establish protocols for producing AHMs capable of replacing damaged heart tissue in either a contractile or electrophysiologic capacity. Optimized AHMs can lead to alternative treatments to heart failure and alleviate the limited donor supply crisis.

Control of colloids with gravity, temperature gradients, and electric fields

CERN Document Server

Sullivan, M; Harrison, C; Austin, R H; Megens, M; Hollingsworth, A; Russel, W B; Cheng Zhen; Mason, T; Chaikin, P M

2003-01-01

We have used a variety of different applied fields to control the density, growth, and structure of colloidal crystals. Gravity exerts a body force proportional to the buoyant mass and in equilibrium produces a height-dependent concentration profile. A similar body force can be obtained with electric fields on charged particles (electrophoresis), a temperature gradient on all particles, or an electric field gradient on uncharged particles (dielectrophoresis). The last is particularly interesting since its magnitude and sign can be changed by tuning the applied frequency. We study these effects in bulk (making 'dielectrophoretic bottles' or traps), to control concentration profiles during nucleation and growth and near surfaces. We also study control of non-spherical and optically anisotropic particles with the light field from laser tweezers.

Control of colloids with gravity, temperature gradients, and electric fields

Energy Technology Data Exchange (ETDEWEB)

Sullivan, Matt [Department of Physics, Princeton University, Princeton, NJ (United States); Zhao Kun [Department of Physics, Princeton University, Princeton, NJ (United States); Harrison, Christopher [Department of Physics, Princeton University, Princeton, NJ (United States); Austin, Robert H [Department of Physics, Princeton University, Princeton, NJ (United States); Megens, Mischa [Department of Physics, Princeton University, Princeton, NJ (United States); Hollingsworth, Andrew [Department of Chemical Engineering, Princeton University, Princeton, NJ (United States); Russel, William B [Department of Chemical Engineering, Princeton University, Princeton, NJ (United States); Cheng Zhengdong [ExxonMobil Research, Annandale, NJ (United States); Mason, Thomas [ExxonMobil Research, Annandale, NJ (United States); Chaikin, P M [Department of Physics, Princeton University, Princeton, NJ (United States)

2003-01-15

We have used a variety of different applied fields to control the density, growth, and structure of colloidal crystals. Gravity exerts a body force proportional to the buoyant mass and in equilibrium produces a height-dependent concentration profile. A similar body force can be obtained with electric fields on charged particles (electrophoresis), a temperature gradient on all particles, or an electric field gradient on uncharged particles (dielectrophoresis). The last is particularly interesting since its magnitude and sign can be changed by tuning the applied frequency. We study these effects in bulk (making 'dielectrophoretic bottles' or traps), to control concentration profiles during nucleation and growth and near surfaces. We also study control of non-spherical and optically anisotropic particles with the light field from laser tweezers.

Hybrid-electric propulsion for automotive and aviation applications

OpenAIRE

Friedrich, C; Robertson, Paul Andrew

2014-01-01

In parallel with the automotive industry, hybrid-electric propulsion is becoming a viable alternative propulsion technology for the aviation sector and reveals potential advantages including fuel savings, lower pollution, and reduced noise emission. Hybrid-electric propulsion systems can take advantage of the synergy between two technologies by utilizing both internal combustion engines and electric motors together, each operating at their respective optimum conditions...

The charged component of the vacuum field as the source of electric ...

African Journals Online (AJOL)

The formula is derived for the electric force inside a uniformly charged spherical body, as well as for the Coulomb force between the charged bodies from the standpoint of the model of the vacuum field with charged particles. The parameters of the fluxes of charged particles are estimated, including the energy density, ...

Examination of biogenic selenium-containing nanosystems based on polyelectrolyte complexes by atomic force, Kelvin probe force and electron microscopy methods

Energy Technology Data Exchange (ETDEWEB)

Sukhanova, T. E., E-mail: tat-sukhanova@mail.ru; Vylegzhanina, M. E.; Valueva, S. V.; Volkov, A. Ya.; Kutin, A. A. [Institute of Macromolecular Compounds RAS, 199004 Bolshoy Pr., 31, St.-Petersburg (Russian Federation); Temiryazeva, M. P.; Temiryazev, A. G. [Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch) Russian Academy of Sciences, Fryazino, Moscow region, 141190 (Russian Federation)

2016-06-17

The morphology and electrical properties of biogenic selenium-containing nanosystems based on polyelectrolyte complexes (PECs) were examined using AFM, Kelvin Probe Force and electron microscopy methods. It has been found, that prepared nanostructures significantly differed in their morphological types and parameters. In particular, multilayers capsules can be produced via varying synthesis conditions, especially, the selenium–PEC mass ratio ν. At the “special point” (ν = 0.1), filled and hollow nano- and microcapsules are formed in the system. The multilayer character of the capsules walls is visible in the phase images. Kelvin Probe Force images showed the inhomogeneity of potential distribution in capsules and outside them.

Research on Grinding and Polishing Force Control of Compliant Flange

Directory of Open Access Journals (Sweden)

Li Chuang

2015-01-01

Full Text Available The automation of the grinding and polishing process is important to improve the production efficiency of the part surfaces. In this paper, a new compliant flange mounted on the end of the industrial robots for the robotic grinding and polishing force control is developed. With regard to the non-linear and time-varying problem of the contact force, the mathematical model of the new force control system was presented and the fuzzy PID control strategy was used to drive the proposed system. Especially, the air spring and electric proportional valve is studied to establish the model. The simulation results show that the selected control strategy has quick response and good robustness, which satisfies the real-time requirements of the grinding and polishing force control in processing.

Principle and Basic Characteristics of Variable-Magnetic-Force Memory Motors

Science.gov (United States)

Sakai, Kazuto; Yuki, Kazuaki; Hashiba, Yutaka; Takahashi, Norio; Yasui, Kazuya; Kovudhikulrungsri, Lilit

A reduction in the power consumed by motors is required for energy saving in the case of electrical appliances and electric vehicles (EV). The motors used for operating these apparatus operate at variable speeds. Further, the motors operate with small load in stationary mode and with large load in start-up mode. A permanent magnet motor can operate at the rated power with a high efficiency. However, the efficiency is lower at small load or high speed because the large constant magnetic force results in substantial core loss. Furthermore, the flux-weakening current that depresses voltage at high speed leads to significant copper loss. Therefore, we have developed a new technique for controlling the magnetic force of permanent magnet on the basis of the load or speed of the motor. In this paper, we propose the novel motor that can vary magnetic flux and we clarify the principle.

Investigation of index finger triggering force using a cadaver experiment: Effects of trigger grip span, contact location, and internal tendon force.

Science.gov (United States)

Chang, Joonho; Freivalds, Andris; Sharkey, Neil A; Kong, Yong-Ku; Mike Kim, H; Sung, Kiseok; Kim, Dae-Min; Jung, Kihyo

2017-11-01

A cadaver study was conducted to investigate the effects of triggering conditions (trigger grip span, contact location, and internal tendon force) on index finger triggering force and the force efficiency of involved tendons. Eight right human cadaveric hands were employed, and a motion simulator was built to secure and control the specimens. Index finger triggering forces were investigated as a function of different internal tendon forces (flexor digitorum profundus + flexor digitorum superficialis = 40, 70, and 100 N), trigger grip spans (40, 50, and 60 mm), and contact locations between the index finger and a trigger. Triggering forces significantly increased when internal tendon forces increased from 40 to 100 N. Also, trigger grip spans and contact locations had significant effects on triggering forces; maximum triggering forces were found at a 50 mm span and the most proximal contact location. The results revealed that only 10-30% of internal tendon forces were converted to their external triggering forces. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of Novel Lateral Tire Force Sensors to Vehicle Parameter Estimation of Electric Vehicles.

Science.gov (United States)

Nam, Kanghyun

2015-11-11

This article presents methods for estimating lateral vehicle velocity and tire cornering stiffness, which are key parameters in vehicle dynamics control, using lateral tire force measurements. Lateral tire forces acting on each tire are directly measured by load-sensing hub bearings that were invented and further developed by NSK Ltd. For estimating the lateral vehicle velocity, tire force models considering lateral load transfer effects are used, and a recursive least square algorithm is adapted to identify the lateral vehicle velocity as an unknown parameter. Using the estimated lateral vehicle velocity, tire cornering stiffness, which is an important tire parameter dominating the vehicle's cornering responses, is estimated. For the practical implementation, the cornering stiffness estimation algorithm based on a simple bicycle model is developed and discussed. Finally, proposed estimation algorithms were evaluated using experimental test data.

Field Measurements of Heating Efficiency of Electric Forced-Air Furnaces in Six Manufactured Homes.

Energy Technology Data Exchange (ETDEWEB)

Davis, Bob; Palmiter, Larry S.; Siegel, Jeff

1994-07-26

This report presents the results of field measurements of heating efficiency for six manufactured homes in the Pacific Northwest heated with electric forced-air systems. This is the first in a series of regional and national efforts to measure in detail the heating efficiency of manufactured homes. Only six homes were included in this study because of budgetary constraints; therefore this is not a representative sample. These investigations do provide some useful information on the heating efficiency of these homes. Useful comparisons can be drawn between these study homes and site-built heating efficiencies measured with a similar protocol. The protocol used to test these homes is very similar to another Ecotope protocol used in the study conducted in 1992 and 1993 for the Bonneville Power Administration to test the heating efficiency of 24 homes. This protocol combined real-time power measurements of furnace energy usage with energy usage during co-heat periods. Accessory data such as house and duct tightness measurements and tracer gas measurements were used to describe these homes and their heating system efficiency. Ensuring that manufactured housing is constructed in an energy and resource efficient manner is of increasing concern to manufactured home builders and consumers. No comparable work has been done to measure the heating system efficiency of MCS manufactured homes, although some co-heat tests have been performed on manufactured homes heated with natural gas to validate HUD thermal standards. It is expected that later in 1994 more research of this kind will be conducted, and perhaps a less costly and less time-consuming method for testing efficiencies will be develops.

On the electrical contact and long-term behavior of compression-type connections with conventional and high-temperature conductor ropes with low sag

International Nuclear Information System (INIS)

Hildmann, Christian

2016-01-01

In Germany and in Europe it is due to the ''Energiewende'' necessary to transmit more electrical energy with existing overhead transmission lines. One possible technical solution to reach this aim is the use of high temperature low sag conductors (HTLS-conductors). Compared to the common Aluminium Conductor Steel Reinforced (ACSR), HTLS-conductors have higher rated currents and rated temperatures. Thus the electrical connections for HTLS-conductors are stressed to higher temperatures too. These components are most important for the safe and reliable operation of an overhead transmission line. Besides other connection technologies, hexagonal compression connections with ordinary transmission line conductors have proven themselves since decades. From the literature, mostly empirical studies with electrical tests for compression connections are known. The electrical contact behaviour, i.e. the quality of the electrical contact after assembly, of these connections has been investigated insufficiently. This work presents and enhances an electrical model of compression connections, so that the electrical contact behaviour can be determined more accurate. Based on this, principal considerations on the current distribution in the compression connection and its influence on the connection resistance are presented. As a result from the theoretical and the experimental work, recommendations for the design of hexagonal compression connections for transmission line conductors were developed. Furthermore it is known from the functional principle of compression type connections, that the electrical contact behaviour can be influenced from their form fit, force fit and cold welding. In particular the forces in compression connections have been calculated up to now by approximation. The known analytical calculations simplify the geometry and material behaviour and do not consider the correct mechanical load during assembly. For these reasons the joining process

Functional evaluation of artificial skeletal muscle tissue constructs fabricated by a magnetic force-based tissue engineering technique.

Science.gov (United States)

Yamamoto, Yasunori; Ito, Akira; Fujita, Hideaki; Nagamori, Eiji; Kawabe, Yoshinori; Kamihira, Masamichi

2011-01-01

Skeletal muscle tissue engineering is currently applied in a variety of research fields, including regenerative medicine, drug screening, and bioactuator development, all of which require the fabrication of biomimic and functional skeletal muscle tissues. In the present study, magnetite cationic liposomes were used to magnetically label C2C12 myoblast cells for the construction of three-dimensional artificial skeletal muscle tissues by an applied magnetic force. Skeletal muscle functions, such as biochemical and contractile properties, were evaluated for the artificial tissue constructs. Histological studies revealed that elongated and multinucleated myotubes were observed within the tissue. Expression of muscle-specific markers, such as myogenin, myosin heavy chain and tropomyosin, were detected in the tissue constructs by western blot analysis. Further, creatine kinase activity increased during differentiation. In response to electric pulses, the artificial tissue constructs contracted to generate a physical force (the maximum twitch force, 33.2 μN [1.06 mN/mm2]). Rheobase and chronaxie of the tissue were determined as 4.45 V and 0.72 ms, respectively. These results indicate that the artificial skeletal muscle tissue constructs fabricated in this study were physiologically functional and the data obtained for the evaluation of their functional properties may provide useful information for future skeletal muscle tissue engineering studies.

Army Energy Initiatives Task Force Industry Summit (portfolio)

Science.gov (United States)

2011-11-03

IY Q N’ZWrt• r Q N’ZWarte US Army Kw•J•I•Io. Atoll. R•public of Monhollltl.nd• fotta..a..,.,., Puerto Rico a (11Jf:!;!6£1) Assistant...Turbine Engines Vehicle connected microgrid to provide assured power Low Speed Electric Vehicles 11 Vehicle Power Energy Initiatives Task Force

Spectral force analysis using atomic force microscopy reveals the importance of surface heterogeneity in bacterial and colloid adhesion to engineered surfaces.

Science.gov (United States)

Ma, Huilian; Winslow, Charles J; Logan, Bruce E

2008-04-01

Coatings developed to reduce biofouling of engineered surfaces do not always perform as expected based on their native properties. One reason is that a relatively small number of highly adhesive sites, or the heterogeneity of the coated surface, may control the overall response of the system to initial bacterial deposition. It is shown here using an approach we call spectral force analysis (SFA), based on force volume imaging of the surface with atomic force microscopy, that the behavior of surfaces and coatings can be better understood relative to bacterial adhesion. The application of vapor deposited TiO(2) metal oxide increased bacterial and colloid adhesion, but coating the surface with silica oxide reduced adhesion in a manner consistent with SFA based on analysis of the "stickiest" sites. Application of a TiO(2)-based paint to a surface produced a relatively non-fouling surface. Addition of a hydrophilic layer coating to this surface should have decreased fouling. However, it was observed that this coating actually increased fouling. Using SFA it was shown that the reason for the increased adhesion of bacteria and particles to the hydrophilic layer was that the surface produced by this coating was highly heterogeneous, resulting in a small number of sites that created a stickier surface. These results show that while it is important to manufacture surfaces with coatings that are relatively non-adhesive to bacteria, it is also essential that these coatings have a highly uniform surface chemistry.

Econometric Modeling: An Application to the Demand for Electricity ...

African Journals Online (AJOL)

The empirical results show an inverse relationship between real appliance purchase price, the real per capita income and the demand for electricity. Also the rate of population growth rate as a proxy for electricity consumers appears to be insignificant. This reveals the clear fact that the demand for electricity is greater than ...

Mathematical modeling and calculation of forced resonant vibrations of composite electromechanical system

OpenAIRE

Ластівка, Іван Олексійович

2014-01-01

Resonant vibrations of composite electromechanical symmetric three-element system “metal plate - piezoceramic cylindrical panels” are considered. Forced vibrations are made under the influence of external alternating electric field, supplied to the electrodes of piezoceramic segments of cylindrical panels, previously polarized in the tangential direction.Based on the improved theory, such as the S.P. Timoshenko’s, the system of differential equations of forced vibrations of the system, taking...

Countermovement jump height: gender and sport-specific differences in the force-time variables.

Science.gov (United States)

Laffaye, Guillaume; Wagner, Phillip P; Tombleson, Tom I L

2014-04-01

The goal of this study was to assess (a) the eccentric rate of force development, the concentric force, and selected time variables on vertical performance during countermovement jump, (b) the existence of gender differences in these variables, and (c) the sport-specific differences. The sample was composed of 189 males and 84 females, all elite athletes involved in college and professional sports (primarily football, basketball, baseball, and volleyball). The subjects performed a series of 6 countermovement jumps on a force plate (500 Hz). Average eccentric rate of force development (ECC-RFD), total time (TIME), eccentric time (ECC-T), Ratio between eccentric and total time (ECC-T:T) and average force (CON-F) were extracted from force-time curves and the vertical jumping performance, measured by impulse momentum. Results show that CON-F (r = 0.57; p differ between both sexes (p differ, showing a similar temporal structure. The best way to jump high is to increase CON-F and ECC-RFD thus minimizing the ECC-T. Principal component analysis (PCA) accounted for 76.8% of the JH variance and revealed that JH is predicted by a temporal and a force component. Furthermore, the PCA comparison made among athletes revealed sport-specific signatures: volleyball players revealed a temporal-prevailing profile, a weak-force with large ECC-T:T for basketball players and explosive and powerful profiles for football and baseball players.

Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 1: formative years, naturphilosophie, and galvanism.

Science.gov (United States)

Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

2013-01-01

During the 1790s, Alexander von Humboldt (1769-1859), who showed an early interest in many facets of natural philosophy and natural history, delved into the controversial subject of galvanism and animal electricity, hoping to shed light on the basic nature of the nerve force. He was motivated by his broad worldview, the experiments of Luigi Galvani, who favored animal electricity in more than a few specialized fishes, and the thinking of Alessandro Volta, who accepted specialized fish electricity but was not willing to generalize to other animals, thinking Galvani's frog experiments flawed by his use of metals. Differing from many German Naturphilosophen, who shunned "violent" experiments, the newest instruments, and detailed measurement, Humboldt conducted thousands of galvanic experiments on animals and animal parts, as well as many on his own body, some of which caused him great pain. He interpreted his results as supporting some but not all of the claims made by both Galvani and Volta. Notably, because of certain negative findings and phenomenological differences, he remained skeptical about the intrinsic animal force being qualitatively identical to true electricity. Hence, he referred to a "galvanic force," not animal electricity, in his letters and publications, a theoretical position he would abandon with Volta's help early in the new century.

Hysteresis Compensation of Piezoresistive Carbon Nanotube/Polydimethylsiloxane Composite-Based Force Sensors

Directory of Open Access Journals (Sweden)

Ji-Sik Kim

2017-01-01

Full Text Available This paper provides a preliminary study on the hysteresis compensation of a piezoresistive silicon-based polymer composite, poly(dimethylsiloxane dispersed with carbon nanotubes (CNTs, to demonstrate its feasibility as a conductive composite (i.e., a force-sensitive resistor for force sensors. In this study, the potential use of the nanotube/polydimethylsiloxane (CNT/PDMS as a force sensor is evaluated for the first time. The experimental results show that the electrical resistance of the CNT/PDMS composite changes in response to sinusoidal loading and static compressive load. The compensated output based on the Duhem hysteresis model shows a linear relationship. This simple hysteresis model can compensate for the nonlinear frequency-dependent hysteresis phenomenon when a dynamic sinusoidal force input is applied.

Magnetic field sensor based on the Ampere's force using dual-polarization DBR fiber laser

Science.gov (United States)

Yao, Shuang; Zhang, Yang; Guan, Baiou

2015-08-01

A novel magnetic field sensor using distributed Bragg reflector (DBR) fiber laser by Ampere's force effect is proposed and experimentally demonstrated. The key sensing element, that is the dual-polarization DBR fiber laser, is fixed on the middle part of two copper plates which carry the current. Ampere's force is applied onto the coppers due to an external magnetic field generated by a DC solenoid. Thus, the lateral force from the coppers is converted to a corresponding beat frequency signal shift produced by the DBR laser. The electric current sensing is also realized by the same configuration and same principle simultaneously in an intuitive manner. Good agreement between the theory calculation and the experimental results is obtained, which shows a good linearity. This sensor's sensitivity to the magnetic field and to the electric current finally reaches ~258.92 kHz/mT and ~1.08727 MHz/A, respectively.

Hull, Mechanical & Electrical (HM &E) Roadmap: Revolutionizing Naval Warfare and Achieving Energy Security

Science.gov (United States)

2012-01-01

Further, recent economic studies have employed full-cost accounting methods ( Kaplan 2011) to estimate the costs force projection in the Persian...Type 45 Destroyer with an IPS and the Type 23 Frigate powered by the Combined Diesel- Electric and Gas Turbine (CODLAG) architecture provides an...Ammunition Ship and the Combined Diesel- Electric or Gas Turbine (CODLOG) (also known as hybrid gas- turbine -electric drive) aboard the USS MAKIN ISLAND

Oscillations of oblate drop between heterogeneous plates under uniform electric field

Science.gov (United States)

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

2018-01-01

The forced oscillations of the incompressible fluid drop under the action of the uniform electric field are considered. In equilibrium, the drop has the form of a circular cylinder bounded axially by the parallel solid planes; the contact angle is right. An incompressible fluid of different density surrounds the drop. The external electric field acts as an external force that causes motion of the contact line. In order to describe this contact line motion, the modified Hocking boundary condition is applied: the velocity of the contact line is proportional to the deviation of the contact angle and the speed of the fast relaxation processes, whose frequency is proportional to twice the frequency of the electric field. The case of heterogeneous plates is investigated. We assume that the Hocking parameter depends on the polar angle in this case. The function describing the change in the coefficient of the interaction between the plate and the fluid (the contact line) is expanded in a series of the Laplace operator eigenfunctions.

Measured long-range repulsive Casimir-Lifshitz forces.

Science.gov (United States)

Munday, J N; Capasso, Federico; Parsegian, V Adrian

2009-01-08

Quantum fluctuations create intermolecular forces that pervade macroscopic bodies. At molecular separations of a few nanometres or less, these interactions are the familiar van der Waals forces. However, as recognized in the theories of Casimir, Polder and Lifshitz, at larger distances and between macroscopic condensed media they reveal retardation effects associated with the finite speed of light. Although these long-range forces exist within all matter, only attractive interactions have so far been measured between material bodies. Here we show experimentally that, in accord with theoretical prediction, the sign of the force can be changed from attractive to repulsive by suitable choice of interacting materials immersed in a fluid. The measured repulsive interaction is found to be weaker than the attractive. However, in both cases the magnitude of the force increases with decreasing surface separation. Repulsive Casimir-Lifshitz forces could allow quantum levitation of objects in a fluid and lead to a new class of switchable nanoscale devices with ultra-low static friction.

Electrical properties of multilayer (DLC-TiC) films produced by pulsed laser deposition

Science.gov (United States)

Alawajji, Raad A.; Kannarpady, Ganesh K.; Nima, Zeid A.; Kelly, Nigel; Watanabe, Fumiya; Biris, Alexandru S.

2018-04-01

In this work, pulsed laser deposition was used to produce a multilayer diamond like carbon (ML (DLC-TiC)) thin film. The ML (DLC-TiC) films were deposited on Si (100) and glass substrates at various substrate temperatures in the range of 20-450 °C. Raman spectroscopy, x-ray photoelectron spectroscopy (XPS), and atomic force microscopy were utilized to characterize the prepared films. Raman analysis revealed that as the substrate temperature increased, the G-peak position shifted to a higher raman shift and the full width at half maximum of the G and D bands decreased. XPS analysis indicated a decrease in sp3/sp2 ratio and an increase in Ti-C bond intensity when the substrate temperature was increased. Additionally, the surface roughness of ML (DLC-TiC) filmswas affected by the type and temperature of the substrate. The electrical measurement results indicated that the electrical resistivity of the ML (DLC-TiC) film deposited on Si and glass substrates showed the same behavior-the resistivity decreased when substrate temperature increased. Furthermore, the ML (DLC-TiC) films deposited on silicon showed lower electrical resistivity, dropping from 8.39E-4 Ω-cm to 5.00E-4 Ω-cm, and, similarly, the films on the glass substrate displayed a drop in electrical resistivity from 1.8E-2 Ω-cm to 1.2E-3 Ω-cm. These enhanced electrical properties indicate that the ML (DLC-TiC) films have widespread potential as transducers for biosensors in biological research; electrochemical electrodes, because these films can be chemically modified; biocompatible coatings for medicals tools; and more.

Application of Novel Lateral Tire Force Sensors to Vehicle Parameter Estimation of Electric Vehicles

Directory of Open Access Journals (Sweden)

Kanghyun Nam

2015-11-01

Full Text Available This article presents methods for estimating lateral vehicle velocity and tire cornering stiffness, which are key parameters in vehicle dynamics control, using lateral tire force measurements. Lateral tire forces acting on each tire are directly measured by load-sensing hub bearings that were invented and further developed by NSK Ltd. For estimating the lateral vehicle velocity, tire force models considering lateral load transfer effects are used, and a recursive least square algorithm is adapted to identify the lateral vehicle velocity as an unknown parameter. Using the estimated lateral vehicle velocity, tire cornering stiffness, which is an important tire parameter dominating the vehicle’s cornering responses, is estimated. For the practical implementation, the cornering stiffness estimation algorithm based on a simple bicycle model is developed and discussed. Finally, proposed estimation algorithms were evaluated using experimental test data.

Electric fields in the magnetosphere

International Nuclear Information System (INIS)

Falthammar, C.G.

1989-01-01

Electric field measurements on the satellites GEOS-1, GEOS-2, ISEE-1, and Viking have extended the empirical knowledge of electric fields in space so as to include the outer regions of the magnetosphere. While the measurements confirm some of the theoretically expected properties of the electric fields, they also reveal unexpected features and a high degree of complexity and variability. The existence of a magnetospheric dawn-to-dusk electric field, as expected on the basis of extrapolation from low altitude measurements, is confirmed in an average sense. However, the actual field exhibits large spatial and temporal variations, including strong fields of inductive origin. At the magnetopause, the average (dawn-to-dusk directed) tangential electric field component is typically obscured by irregular fluctuations of larger amplitude. The magnetic-field aligned component of the electric field, which is of particular importance for ionosphere-magnetosphere coupling and for auroral acceleration, is even now very difficult to measure directly. However, the data from electric field measurements provide further support for the conclusion, based on a variety of evidence, that a non-vanishing magnetic-field aligned electric field exists in the auroral acceleration region

Localization and force analysis at the single virus particle level using atomic force microscopy

Energy Technology Data Exchange (ETDEWEB)

Liu, Chih-Hao [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Horng, Jim-Tong [Department of Biochemistry, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan (China); Chang, Jeng-Shian [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Hsieh, Chung-Fan [Graduate Institute of Biomedical Sciences, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China); Tseng, You-Chen [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Lin, Shiming, E-mail: til@ntu.edu.tw [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Optoelectronic Biomedicine, College of Medicine, Nation Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan (China)

2012-01-06

Highlights: Black-Right-Pointing-Pointer Localization of single virus particle. Black-Right-Pointing-Pointer Force measurements. Black-Right-Pointing-Pointer Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

Gyrokinetic electron acceleration in the force-free corona with anomalous resistivity

OpenAIRE

Arzner, Kaspar; Vlahos, Loukas

2006-01-01

We numerically explore electron acceleration and coronal heating by dissipative electric fields. Electrons are traced in linear force-free magnetic fields extrapolated from SOHO/MDI magnetograms, endowed with anomalous resistivity ($\\eta$) in localized dissipation regions where the magnetic twist $\

Development of a Carbon Nanotube-Based Touchscreen Capable of Multi-Touch and Multi-Force Sensing

Directory of Open Access Journals (Sweden)

Wonhyo Kim

2015-11-01

Full Text Available A force sensing touchscreen, which detects touch point and touch force simultaneously by sensing a change in electric capacitance, was designed and fabricated. It was made with single-walled carbon nanotubes (SWCNTs which have better mechanical and chemical characteristics than the indium-tin-oxide transparent electrodes used in most contemporary touchscreen devices. The SWCNTs, with a transmittance of about 85% and electric conductivity of 400 Ω per square; were coated and patterned on glass and polyethyleneterephthalate (PET film substrates. The constructed force sensing touchscreen has a total size and thickness of 62 mm × 100 mm × 1.4 mm, and is composed of 11 driving line and 19 receiving line channels. The gap between the channels was designed to be 20 µm, taking visibility into consideration, and patterned by a photolithography and plasma etching processes. The mutual capacitance formed by the upper and lower transparent electrodes was initially about 2.8 pF and, on applying a 500 gf force with a 3 mm diameter tip, it showed a 25% capacitance variation. Furthermore, the touchscreen can detect multiple touches and forces simultaneously and is unaffected by touch material characteristics, such as conductance or non-conductance.

Development of a Carbon Nanotube-Based Touchscreen Capable of Multi-Touch and Multi-Force Sensing.

Science.gov (United States)

Kim, Wonhyo; Oh, Haekwan; Kwak, Yeonhwa; Park, Kwangbum; Ju, Byeong-Kwon; Kim, Kunnyun

2015-11-13

A force sensing touchscreen, which detects touch point and touch force simultaneously by sensing a change in electric capacitance, was designed and fabricated. It was made with single-walled carbon nanotubes (SWCNTs) which have better mechanical and chemical characteristics than the indium-tin-oxide transparent electrodes used in most contemporary touchscreen devices. The SWCNTs, with a transmittance of about 85% and electric conductivity of 400 Ω per square; were coated and patterned on glass and polyethyleneterephthalate (PET) film substrates. The constructed force sensing touchscreen has a total size and thickness of 62 mm × 100 mm × 1.4 mm, and is composed of 11 driving line and 19 receiving line channels. The gap between the channels was designed to be 20 µm, taking visibility into consideration, and patterned by a photolithography and plasma etching processes. The mutual capacitance formed by the upper and lower transparent electrodes was initially about 2.8 pF and, on applying a 500 gf force with a 3 mm diameter tip, it showed a 25% capacitance variation. Furthermore, the touchscreen can detect multiple touches and forces simultaneously and is unaffected by touch material characteristics, such as conductance or non-conductance.

Proof of Concept: Model Based Bionic Muscle with Hyperbolic Force-Velocity Relation

Directory of Open Access Journals (Sweden)

D. F. B. Haeufle

2012-01-01

Full Text Available Recently, the hyperbolic Hill-type force-velocity relation was derived from basic physical components. It was shown that a contractile element CE consisting of a mechanical energy source (active element AE, a parallel damper element (PDE, and a serial element (SE exhibits operating points with hyperbolic force-velocity dependency. In this paper, a technical proof of this concept was presented. AE and PDE were implemented as electric motors, SE as a mechanical spring. The force-velocity relation of this artificial CE was determined in quick release experiments. The CE exhibited hyperbolic force-velocity dependency. This proof of concept can be seen as a well-founded starting point for the development of Hill-type artificial muscles.

Performance of Cableless Magnetic In-Piping Actuator Capable of High-Speed Movement by Means of Inertial Force

Directory of Open Access Journals (Sweden)

Hiroyuki Yaguchi

2011-01-01

Full Text Available The present paper proposes a novel cableless magnetic actuator with a new propulsion module that exhibits a very high thrusting force. This actuator contains an electrical inverter that directly transforms DC from button batteries into AC. The electrical DC-AC inverter incorporates a mass-spring system, a reed switch, and a curved permanent magnet that switches under an electromagnetic force. The actuator is moved by the inertial force of the mass-spring system due to mechanical resonance energy. The experimental results show that the actuator is able to move upward at a speed of 19.7 mm/s when using 10 button batteries when pulling a 20 g load mass. This cableless magnetic actuator has several possible applications, including narrow pipe inspection and maintenance.

Electrical current leakage and open-core threading dislocations in AlGaN-based deep ultraviolet light-emitting diodes

International Nuclear Information System (INIS)

Moseley, Michael; Allerman, Andrew; Crawford, Mary; Wierer, Jonathan J.; Smith, Michael; Biedermann, Laura

2014-01-01

Electrical current transport through leakage paths in AlGaN-based deep ultraviolet (DUV) light-emitting diodes (LEDs) and their effect on LED performance are investigated. Open-core threading dislocations, or nanopipes, are found to conduct current through nominally insulating Al 0.7 Ga 0.3 N layers and limit the performance of DUV-LEDs. A defect-sensitive phosphoric acid etch reveals these open-core threading dislocations in the form of large, micron-scale hexagonal etch pits visible with optical microscopy, while closed-core screw-, edge-, and mixed-type threading dislocations are represented by smaller and more numerous nanometer-scale pits visible by atomic-force microscopy. The electrical and optical performances of DUV-LEDs fabricated on similar Si-doped Al 0.7 Ga 0.3 N templates are found to have a strong correlation to the density of these nanopipes, despite their small fraction (<0.1% in this study) of the total density of threading dislocations

Force estimation from ensembles of Golgi tendon organs

Science.gov (United States)

Mileusnic, M. P.; Loeb, G. E.

2009-06-01

Golgi tendon organs (GTOs) located in the skeletal muscles provide the central nervous system with information about muscle tension. The ensemble firing of all GTO receptors in the muscle has been hypothesized to represent a reliable measure of the whole muscle force but the precision and accuracy of that information are largely unknown because it is impossible to record activity simultaneously from all GTOs in a muscle. In this study, we combined a new mathematical model of force sampling and transduction in individual GTOs with various models of motor unit (MU) organization and recruitment simulating various normal, pathological and neural prosthetic conditions. Our study suggests that in the intact muscle the ensemble GTO activity accurately encodes force information according to a nonlinear, monotonic relationship that has its steepest slope for low force levels and tends to saturate at the highest force levels. The relationship between the aggregate GTO activity and whole muscle tension under some pathological conditions is similar to one seen in the intact muscle during rapidly modulated, phasic excitation of the motor pool (typical for many natural movements) but quite different when the muscle is activated slowly or held at a given force level. Substantial deviations were also observed during simulated functional electrical stimulation.

Improved Parameters for the Martini Coarse-Grained Protein Force Field

NARCIS (Netherlands)

de Jong, Djurre H.; Singh, Gurpreet; Bennett, W. F. Drew; Arnarez, Clement; Wassenaar, Tsjerk A.; Schafer, Lars V.; Periole, Xavier; Tieleman, D. Peter; Marrink, Siewert J.

The Martini coarse-grained force field has been successfully used for simulating a wide range of (bio)molecular systems. Recent progress in our ability to test the model against fully atomistic force fields, however, has revealed some shortcomings. Most notable, phenylalanine and proline were too

New South Wales' new electricity transmission authority

International Nuclear Information System (INIS)

Fahey, J.

1995-01-01

The latest milestone in electricity reform in NSW was the formation of a new statutory authority, the Electricity Transmission Authority (ETA), to take over and operate the transmission assets of Pacific Power, formerly the New South Wales Electricity Commission. The ETA will be operational from 1 February 1995, in time for the proposed commencement of a national electricity market on 1 July 1995. The forces of competition are being used to improve the efficiency of the industry, to empower consumers with greater choice and to open up new opportunities for private-sector participation in the industry. Potentially commercial activities such as coal mines have been separated from the operational arm of Pacific Power so that they have to compete with the private sector in supplying power stations. Significant reductions have been made in the price of electricity to reduce existing cross-subsidizations so that commercial and industrial customers gain the biggest benefits. The new ETA will pay dividends to the NSW government, as private companies pay dividends to their shareholders, and it will be subject to the federal tax-equivalent regime. 2 photos

Muscle spindle thixotropy affects force perception through afferent-induced facilitation of the motor pathways as revealed by the Kohnstamm effect.

Science.gov (United States)

Monjo, Florian; Forestier, Nicolas

2018-04-01

This study was designed to explore the effects of intrafusal thixotropy, a property affecting muscle spindle sensitivity, on the sense of force. For this purpose, psychophysical measurements of force perception were performed using an isometric force matching paradigm of elbow flexors consisting of matching different force magnitudes (5, 10 and 20% of subjects' maximal voluntary force). We investigated participants' capacity to match these forces after their indicator arm had undergone voluntary isometric conditioning contractions known to alter spindle thixotropy, i.e., contractions performed at long ('hold long') or short muscle lengths ('hold short'). In parallel, their reference arm was conditioned at the intermediate muscle length ('hold-test') at which the matchings were performed. The thixotropy hypothesis predicts that estimation errors should only be observed at low force levels (up to 10% of the maximal voluntary force) with overestimation of the forces produced following 'hold short' conditioning and underestimation following 'hold long' conditioning. We found the complete opposite, especially following 'hold-short' conditioning where subjects underestimated the force they generated with similar relative error magnitudes across force levels. In a second experiment, we tested the hypothesis that estimation errors depended on the degree of afferent-induced facilitation using the Kohnstamm phenomenon as a probe of motor pathway excitability. Because the stronger post-effects were observed following 'hold-short' conditioning, it appears that the conditioning-induced excitation of spindle afferents leads to force misjudgments by introducing a decoupling between the central effort and the cortical motor outputs.

Electrostatic forces on grains near asteroids and comets

Directory of Open Access Journals (Sweden)

Hartzell Christine

2017-01-01

Full Text Available Dust on and near the surface of small planetary bodies (e.g. asteroids, the Moon, Mars’ moons is subject to gravity, cohesion and electrostatic forces. Due to the very low gravity on small bodies, the behavior of small dust grains is driven by non-gravitational forces. Recent work by Scheeres et al. has shown that cohesion, specifically van der Waals force, is significant for grains on asteroids. In addition to van der Waals cohesion, dust grains also experience electrostatic forces, arising from their interaction with each other (through tribocharging and the solar wind plasma (which produces both grain charging and an external electric field. Electrostatic forces influence both the interactions of grains on the surface of small bodies as well as the dynamics of grains in the plasma sheath above the surface. While tribocharging between identical dielectric grains remains poorly understood, we have recently expanded an existing charge transfer model to consider continuous size distributions of grains and are planning an experiment to test the charge predictions produced. Additionally, we will present predictions of the size of dust grains that are capable of detaching from the surface of small bodies.

Variational integrators for electric circuits

International Nuclear Information System (INIS)

Ober-Blöbaum, Sina; Tao, Molei; Cheng, Mulin; Owhadi, Houman; Marsden, Jerrold E.

2013-01-01

In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator

Dynamic steering beams for efficient force measurement in optical manipulation

Institute of Scientific and Technical Information of China (English)

Xiaocong Yuan; Yuquan Zhang; Rui Cao; Xing Zhao; Jing Bu; Siwei Zhu

2011-01-01

@@ An efficient and inexpensive method that uses a glass plate mounted onto a motorized rotating stage as a beam-steering device for the generation of dynamic optical traps is reported.Force analysis reveals that there are drag and trapping forces imposed on the bead in the opposite directions, respectively, in a viscous medium.The trapped bead will be rotated following the beam's motion before it reaches the critical escape velocity when the drag force is equal to the optical trapping force.The equilibrium condition facilitates the experimental measurement of the drag force with potential extensions to the determination of the viscosity of the medium or the refractive index of the bead.The proposed technique can easily be integrated into conventional optical microscopic systems with minimum modifications.%An efficient and inexpensive method that uses a glass plate mounted onto a motorized rotating stage as a beam-steering device for the generation of dynamic optical traps is reported. Force analysis reveals that there are drag and trapping forces imposed on the bead in the opposite directions, respectively, in a viscous medium. The trapped bead will be rotated following the beam's motion before it reaches the critical escape velocity when the drag force is equal to the optical trapping force. The equilibrium condition facilitates the experimental measurement of the drag force with potential extensions to the determination of the viscosity of the medium or the refractive index of the bead. The proposed technique can easily be integrated into conventional optical microscopic systems with minimum modifications.

Direct observation of the leakage current in epitaxial diamond Schottky barrier devices by conductive-probe atomic force microscopy and Raman imaging

Science.gov (United States)

Alvarez, J.; Boutchich, M.; Kleider, J. P.; Teraji, T.; Koide, Y.

2014-09-01

The origin of the high leakage current measured in several vertical-type diamond Schottky devices is conjointly investigated by conducting probe atomic force microscopy and confocal micro-Raman/photoluminescence imaging analysis. Local areas characterized by a strong decrease of the local resistance (5-6 orders of magnitude drop) with respect to their close surrounding have been identified in several different regions of the sample surface. The same local areas, also referenced as electrical hot-spots, reveal a slightly constrained diamond lattice and three dominant Raman bands in the low-wavenumber region (590, 914 and 1040 cm-1). These latter bands are usually assigned to the vibrational modes involving boron impurities and its possible complexes that can electrically act as traps for charge carriers. Local current-voltage measurements performed at the hot-spots point out a trap-filled-limited current as the main conduction mechanism favouring the leakage current in the Schottky devices.

Direct observation of the leakage current in epitaxial diamond Schottky barrier devices by conductive-probe atomic force microscopy and Raman imaging

International Nuclear Information System (INIS)

Alvarez, J; Boutchich, M; Kleider, J P; Teraji, T; Koide, Y

2014-01-01

The origin of the high leakage current measured in several vertical-type diamond Schottky devices is conjointly investigated by conducting probe atomic force microscopy and confocal micro-Raman/photoluminescence imaging analysis. Local areas characterized by a strong decrease of the local resistance (5–6 orders of magnitude drop) with respect to their close surrounding have been identified in several different regions of the sample surface. The same local areas, also referenced as electrical hot-spots, reveal a slightly constrained diamond lattice and three dominant Raman bands in the low-wavenumber region (590, 914 and 1040 cm −1 ). These latter bands are usually assigned to the vibrational modes involving boron impurities and its possible complexes that can electrically act as traps for charge carriers. Local current–voltage measurements performed at the hot-spots point out a trap-filled-limited current as the main conduction mechanism favouring the leakage current in the Schottky devices. (paper)

Direct numerical simulation of MHD flow with electrically conducting wall

International Nuclear Information System (INIS)

Satake, S.; Kunugi, T.; Naito, N.; Sagara, A.

2006-01-01

The 2D vortex problem and 3D turbulent channel flow are treated numerically to assess the effect of electrically conducting walls on turbulent MHD flow. As a first approximation, the twin vortex pair is considered as a model of a turbulent eddy near the wall. As the eddy approaches and collides with the wall, a high value electrical potential is induced inside the wall. The Lorentz force, associated with the potential distribution, reduces the velocity gradient in the near-wall region. When considering a fully developed turbulent channel flow, a high electrical conductivity wall was chosen to emphasize the effect of electromagnetic coupling between the wall and the flow. The analysis was performed using DNS. The results are compared with a non-MHD flow and MHD flow in the insulated channel. The mean velocity within the logarithmic region in the case of the electrically conducting wall is slightly higher than that in the non-conducting wall case. Thus, the drag is smaller compared to that in the non-conducting wall case due to a reduction of the Reynolds stress in the near wall region through the Lorentz force. This mechanism is explained via reduction of the production term in the Reynolds shear stress budget

High-Fidelity Simulations of Electrically-Charged Atomizing Diesel-Type Jets

Science.gov (United States)

Gaillard, Benoit; Owkes, Mark; van Poppel, Bret

2015-11-01

Combustion of liquid fuels accounts for over a third of the energy usage today. Improving efficiency of combustion systems is critical to meet the energy needs while limiting environmental impacts. Additionally, a shift away from traditional fossil fuels to bio-derived alternatives requires fuel injection systems that can atomize fuels with a wide range of properties. In this work, the potential benefits of electrically-charged atomization is investigated using numerical simulations. Particularly, the electrostatic forces on the hydrodynamic jet are quantified and the impact of the forces is analyzed by comparing simulations of Diesel-type jets at realistic flow conditions. The simulations are performed using a state-of-the-art numerical framework that globally conserves mass, momentum, and the electric charge density even at the gas-liquid interface where discontinuities exist.

Bilateral Electrical Cataract: A Case Report

Directory of Open Access Journals (Sweden)

Selçuk Sızmaz

2011-06-01

Full Text Available To present a rare complication, such as bilateral cataracts, in a man who sustained a high-voltage electrical injury. A 35- year-old man was admitted with a complaint of decrease in visual acuity. He had a history of a contact with a power line carrying 30.000 volts of electricity while working at a construction site. Examination at a burn center revealed second-degree facial, neck and left foot burns. One month later, the patient underwent amputation of fourth and fifth toes of his left foot. During the next 6 months, he noted decreasing vision in both eyes. Ocular examination 1 year after the accident revealed that the patient’s visual acuity had deteriorated to 1/10 in both eyes. The cornea on the left eye showed superficial punctate opacities. The lenses in both eyes had anterior subcapsular cortical lens opacities and posterior subcapsular opacities. Uncomplicated bilateral phacoemulsification surgery with intraocular lens implantation was performed and the patient’s visual acuity returned to 10/10 in both eyes. We noted that the fundus remained normal in both eyes. Electrical cataracts are still a serious potential complication that may occur after electrical injury. Awareness of this by burn team members is important for providing optimal treatment to those who have suffered an electrical injury. (Turk J Ophthalmol 2011; 41: 197-9

The Predominance of Electric Transport in Synaptic Transmission

OpenAIRE

Hamid Reza Noori

2008-01-01

The quantitative description of the motion of neurotransmitters in the synaptic cleft appears to be one of the most difficult problems in the modeling of synapses. Here we show in contradiction to the common view, that this process is merely governed by electric transport than diffusion forces.

Discovery Mondays - The particle physicist's best friend: electricity

CERN Document Server

2005-01-01

One of CERN's electrical substations, at Prévessin. Electricity is one of CERN's closest allies. Without it, none of the physicists' extraordinary instruments would work. It is electricity that will guide and accelerate particles around the 27-km ring of the world's most powerful accelerator, the LHC. In the giant magnets inside the experiments electricity is also used to produce a magnetic field 200,000 times greater than the Earth's own magnetic field. Inside the detectors, the resulting magnetic force is used to bend the trajectories of the particles, allowing them to be identified and helping us gain a better understanding of what has happened at the heart of the collisions. Understanding how magnetic fields are produced inside the ATLAS experiment is one of several themes on the programme of the next Discovery Monday. And for a close-up view of operations, we'll also be taking you on a visit to the electricity substation at Meyrin. Come and meet CERN's best friend - electricity. Join us at the Micro...

Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

Directory of Open Access Journals (Sweden)

Miriam Jaafar

2011-09-01

Full Text Available The most outstanding feature of scanning force microscopy (SFM is its capability to detect various different short and long range interactions. In particular, magnetic force microscopy (MFM is used to characterize the domain configuration in ferromagnetic materials such as thin films grown by physical techniques or ferromagnetic nanostructures. It is a usual procedure to separate the topography and the magnetic signal by scanning at a lift distance of 25–50 nm such that the long range tip–sample interactions dominate. Nowadays, MFM is becoming a valuable technique to detect weak magnetic fields arising from low dimensional complex systems such as organic nanomagnets, superparamagnetic nanoparticles, carbon-based materials, etc. In all these cases, the magnetic nanocomponents and the substrate supporting them present quite different electronic behavior, i.e., they exhibit large surface potential differences causing heterogeneous electrostatic interaction between the tip and the sample that could be interpreted as a magnetic interaction. To distinguish clearly the origin of the tip–sample forces we propose to use a combination of Kelvin probe force microscopy (KPFM and MFM. The KPFM technique allows us to compensate in real time the electrostatic forces between the tip and the sample by minimizing the electrostatic contribution to the frequency shift signal. This is a great challenge in samples with low magnetic moment. In this work we studied an array of Co nanostructures that exhibit high electrostatic interaction with the MFM tip. Thanks to the use of the KPFM/MFM system we were able to separate the electric and magnetic interactions between the tip and the sample.

The Röntgen interaction and forces on dipoles in time-modulated optical fields

Science.gov (United States)

Sonnleitner, Matthias; Barnett, Stephen M.

2017-12-01

The Röntgen term is an often neglected contribution to the interaction between an atom and an electromagnetic field in the electric dipole approximation. In this work we discuss how this interaction term leads to a difference between the kinetic and canonical momentum of an atom which, in turn, leads to surprising radiation forces acting on the atom. We use a number of examples to explore the main features of this interaction, namely forces acting against the expected dipole force or accelerations perpendicular to the beam propagation axis.

Improving Energy Security for Air Force Installations

Science.gov (United States)

2015-09-01

equipment, and habitat destruction from general construction (DoE, “ Wind Turbine Interactions with Birds , Bats, and Their Habitats,” pgs 2-4). Another...utility-resource-efficiency>, accessed 16 December 2014. Department of Energy, Wind Turbine Interactions with Birds , Bats, and Their Habitats... Wind power is a mature technology, with wind turbines first being used for electricity in the late 19th century. The Air Force operates two wind

Cavity opto-electromechanical system combining strong electrical actuation with ultrasensitive transduction

OpenAIRE

McRae, Terry G.; Lee, Kwan H.; Harris, Glen I.; Knittel, Joachim; Bowen, Warwick P.

2010-01-01

A cavity opto-electromechanical system is reported which combines the ultrasensitive transduction of cavity optomechanical systems with the electrical actuation of nanoelectromechanical systems. Ultrasensitive mechanical transduction is achieved via opto-mechanical coupling. Electrical gradient forces as large as 0.40 $\\mu$N are realized, facilitating strong actuation with ultralow dissipation. A scanning probe microscope is implemented, capable of characterizing the mechanical modes. The int...

Secondary School Students' Misconceptions about Simple Electric Circuits

Science.gov (United States)

Küçüközer, Hüseyin; Kocakülah, Sabri

2007-01-01

The aim of this study is to reveal secondary school students' misconceptions about simple electric circuits and to define whether specific misconceptions peculiar to Turkish students exist within those identified. Data were obtained with a conceptual understanding test for simple electric circuits and semi-structured interviews. Conceptual…

Effects of tensor forces in nuclei

International Nuclear Information System (INIS)

Tanihata, Isao

2013-01-01

Recent studies of nuclei far from the stability line have revealed drastic changes in nuclear orbitals and reported the appearance of new magic numbers and the disappearance of magic numbers observed at the stability line. One of the important reasons for such changes is considered to be because of the effect of tensor forces on nuclear structure. Although the role of tensor forces in binding very light nuclei such as deuterons and 4 He has been known, direct experimental evidence for the effect on nuclear structure is scarce. In this paper, I review known effects of tensor forces in nuclei and then discuss the recently raised question of s–p wave mixing in a halo nucleus of 11 Li. Following these reviews, the development of a new experiment to see the high-momentum components due to the tensor forces is discussed and some of the new data are presented. (paper)

Small-scale electric generators for arctic applications

International Nuclear Information System (INIS)

Lamp, T.R.

1995-01-01

Forest fires that have endangered remote US Air Force sites equipped with radioisotope thermoelectric generators (RTGs) has prompted the assessment of power generating systems as substitutes for RTGs in small scale (10--120 watt) applications. A team of scientists and engineers of the US Air Forces' Wright Laboratory conductd an assessment of electrical power technologies for use by the Air Force in remote, harsh environments. The surprisingly high logistics costs of operating fossil fuel generators resulted in the extension of the assessment to non-RTG sites. The candidate power sources must operate unattended for long periods at a high level of operational reliability. Selection of the optimum power generation technology is complicated and heavily driven by the severe operating environment and compounded by the remoteness of the location. It is these site-related characteristics, more than any other, that drive the selection of a safe and economical power source for Arctic applications. A number of proven power generation technologies were evaluated. The assessment concluded that RGTs are clearly the safest, most reliable, and most economical approach to supplying electrical power for remote, difficult to assess locations. The assessment also indicated that the logistics costs associated with combustion driven generator systems could be substantially reduced through the use of conversion technologies which have been previously developed for space power applications. copyright 1995 American Institute of Physics

Development of dust removal system using static electricity for fusion experimental reactors

Energy Technology Data Exchange (ETDEWEB)

Onozuka, Masanori; Ueda, Yasutoshi; Oda, Yasushi; Takahashi, Kenji [Mitsubishi Heavy Industries Ltd., Tokyo (Japan); Seki, Yasushi; Aoki, Isao; Ueda, Shuzo; Kurihara, Ryoichi

1997-11-01

Tests to collect and transport metallic and non-metallic dust particles have been conducted using static electricity in a vacuum environment to investigate the applicability of a static electricity dust removal system for fusion experimental reactors. The dust particles are charged by electrostatic induction, floated and collected due to the Coulomb force generated by the AC electric field. They are then transported due to the gradient force induced by the electric curtain of the non-uniform travelling-wave electric field. Using a fully insulated electrode with a single-phase AC voltage up to 15 kV, aluminum and carbon dust were successfully collected. The highest collection rates for the aluminum and carbon dust were around 30 and 2 g/min, respectively. The linear-type electrodes, using as high as 22 kV of the three-phase AC voltage, transported aluminum dust up to an angle of 60deg. Applying a guide electrode to the linear-type electrode, the transportation rate was approximately doubled and almost constant at every angle, including a 90deg angle. The system transported aluminum dust up to the rate of 13 g/min. The influence of the 0.15 T magnetic field on the dust collection and transportation efficiencies was found to be negligible. (author)

Development of dust removal system using static electricity for fusion experimental reactors

International Nuclear Information System (INIS)

Onozuka, Masanori; Ueda, Yasutoshi; Oda, Yasushi; Takahashi, Kenji; Seki, Yasushi; Aoki, Isao; Ueda, Shuzo; Kurihara, Ryoichi.

1997-01-01

Tests to collect and transport metallic and non-metallic dust particles have been conducted using static electricity in a vacuum environment to investigate the applicability of a static electricity dust removal system for fusion experimental reactors. The dust particles are charged by electrostatic induction, floated and collected due to the Coulomb force generated by the AC electric field. They are then transported due to the gradient force induced by the electric curtain of the non-uniform travelling-wave electric field. Using a fully insulated electrode with a single-phase AC voltage up to 15 kV, aluminum and carbon dust were successfully collected. The highest collection rates for the aluminum and carbon dust were around 30 and 2 g/min, respectively. The linear-type electrodes, using as high as 22 kV of the three-phase AC voltage, transported aluminum dust up to an angle of 60deg. Applying a guide electrode to the linear-type electrode, the transportation rate was approximately doubled and almost constant at every angle, including a 90deg angle. The system transported aluminum dust up to the rate of 13 g/min. The influence of the 0.15 T magnetic field on the dust collection and transportation efficiencies was found to be negligible. (author)

Bio-inspired ciliary force sensor for robotic platforms

KAUST Repository

Ribeiro, Pedro; Khan, Mohammed Asadullah; Alfadhel, Ahmed; Kosel, Jü rgen; Franco, Fernando; Cardoso, Susana; Bernardino, Alexandre; Schmitz, Alexander; Santos-Victor, Jose; Jamone, Lorenzo