Design, manufacture and performance evaluation of HTS electromagnets for the hybrid magnetic levitation system

Science.gov (United States)

Chu, S. Y.; Hwang, Y. J.; Choi, S.; Na, J. B.; Kim, Y. J.; Chang, K. S.; Bae, D. K.; Lee, C. Y.; Ko, T. K.

2011-11-01

A high speed electromagnetic suspension (EMS) maglev has emerged as the solution to speed limit problem that conventional high-speed railroad has. In the EMS maglev, small levitation gap needs uniform guide-way which leads to increase the construction cost. The large levitation gap can reduce the construction cost. However it is hard for normal conducting electromagnet to produce larger magneto-motive force (MMF) for generating levitation force as increased levitation gap. This is because normal conductors have limited rating current to their specific volume. Therefore, the superconducting electromagnet can be one of the solutions for producing both large levitation gap and sufficient MMF. The superconducting electromagnets have incomparably high allowable current density than what normal conductors have. In this paper, the prototype of high temperature superconducting (HTS) electromagnets were designed and manufactured applicable to hybrid electromagnetic suspension system (H-EMS). The H-EMS consists of control coils for levitation control and superconducting coils for producing MMF for levitation. The required MMF for generating given levitation force was calculated by both equations of ideal U-core magnet and magnetic field analysis using the finite element method (FEM). The HTS electromagnets were designed as double pancakes with Bi-2223/Ag tapes. Experiments to confirm its operating performance were performed in liquid nitrogen (LN2).

Design, manufacture and performance evaluation of HTS electromagnets for the hybrid magnetic levitation system

Energy Technology Data Exchange (ETDEWEB)

Chu, S.Y.; Hwang, Y.J.; Choi, S.; Na, J.B.; Kim, Y.J.; Chang, K.S. [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Bae, D.K. [Chungju National University, Chungju 380-702 (Korea, Republic of); Lee, C.Y. [Ultra High-Speed Train Research Department, Korea Railroad Research Institute, Uiwang-Si 437-757 (Korea, Republic of); Ko, T.K., E-mail: tkko@yonsei.ac.kr [School of Electrical and Electronic Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

2011-11-15

A high speed electromagnetic suspension (EMS) maglev has emerged as the solution to speed limit problem that conventional high-speed railroad has. In the EMS maglev, small levitation gap needs uniform guide-way which leads to increase the construction cost. The large levitation gap can reduce the construction cost. However it is hard for normal conducting electromagnet to produce larger magneto-motive force (MMF) for generating levitation force as increased levitation gap. This is because normal conductors have limited rating current to their specific volume. Therefore, the superconducting electromagnet can be one of the solutions for producing both large levitation gap and sufficient MMF. The superconducting electromagnets have incomparably high allowable current density than what normal conductors have. In this paper, the prototype of high temperature superconducting (HTS) electromagnets were designed and manufactured applicable to hybrid electromagnetic suspension system (H-EMS). The H-EMS consists of control coils for levitation control and superconducting coils for producing MMF for levitation. The required MMF for generating given levitation force was calculated by both equations of ideal U-core magnet and magnetic field analysis using the finite element method (FEM). The HTS electromagnets were designed as double pancakes with Bi-2223/Ag tapes. Experiments to confirm its operating performance were performed in liquid nitrogen (LN{sub 2}).

An isotropic suspension system for a biaxial accelerometer using electroplated thick metal with a HAR SU-8 mold

International Nuclear Information System (INIS)

Lee, Jin Seung; Lee, Seung S

2008-01-01

In this paper, a novel approach is developed to design an isotropic suspension system using thick metal freestanding micro-structures combining bulk micro-machining with electroplating based on a HAR SU-8 mold. An omega-shape isotropic suspension system composed of circular curved beams that have free switching of imaginary boundary conditions is proposed. This novel isotropic suspension design is not affected by geometric dimensional parameters and always achieves matching stiffness along the principle axes of elasticity. Using the finite element method, the isotropic suspension system was compared with an S-shaped meandering suspension system. In order to realize the suggested isotropic suspension system, a cost-effective fabrication process using electroplating with the SU-8 mold was developed to avoid expensive equipment and materials such as deep reactive-ion etching (DRIE) or a silicon-on-insulator (SOI) wafer. The fabricated isotropic suspension system was verified by electromagnetic actuation experiments. Finally, a biaxial accelerometer with isotropic suspension system was realized and tested using a vibration generator system. The proposed isotropic suspension system and the modified surface micro-machining technique based on electroplating with an SU-8 mold can contribute towards minimizing the system size, simplifying the system configuration, reducing the system price of and facilitating mass production of various types of low-cost sensors and actuators

Motion control of a large gap magnetic suspension system for microrobotic manipulation

Energy Technology Data Exchange (ETDEWEB)

Craig, David; Khamesee, Mir Behrad [Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario, N2L 3G1 (Canada)

2007-06-07

Magnetic suspension systems have shown a great deal of promise in the field of microrobotics. This paper discusses the performance of a new large gap magnetic suspension system developed by the researchers. The magnetic drive unit consists of six electromagnets attached to a soft iron pole piece and yoke. Levitation of an 11.19 g microrobot prototype is demonstrated for step, ramp and periodic input trajectories using PID control. The working envelope of the microrobot is 30 x 22 x 20 mm{sup 3}, with an RMS error on the order of 18 {mu}m in the vertical direction and 8 {mu}m in the horizontal direction. It is demonstrated that the levitated microrobot is able to track the desired trajectory precisely and that the system has potential application for micromanipulation.

Motion control of a large gap magnetic suspension system for microrobotic manipulation

International Nuclear Information System (INIS)

Craig, David; Khamesee, Mir Behrad

2007-01-01

Magnetic suspension systems have shown a great deal of promise in the field of microrobotics. This paper discusses the performance of a new large gap magnetic suspension system developed by the researchers. The magnetic drive unit consists of six electromagnets attached to a soft iron pole piece and yoke. Levitation of an 11.19 g microrobot prototype is demonstrated for step, ramp and periodic input trajectories using PID control. The working envelope of the microrobot is 30 x 22 x 20 mm 3 , with an RMS error on the order of 18 μm in the vertical direction and 8 μm in the horizontal direction. It is demonstrated that the levitated microrobot is able to track the desired trajectory precisely and that the system has potential application for micromanipulation

The Active Fractional Order Control for Maglev Suspension System

Directory of Open Access Journals (Sweden)

Peichang Yu

2015-01-01

Full Text Available Maglev suspension system is the core part of maglev train. In the practical application, the load uncertainties, inherent nonlinearity, and misalignment between sensors and actuators are the main issues that should be solved carefully. In order to design a suitable controller, the attention is paid to the fractional order controller. Firstly, the mathematical model of a single electromagnetic suspension unit is derived. Then, considering the limitation of the traditional PD controller adaptation, the fractional order controller is developed to obtain more excellent suspension specifications and robust performance. In reality, the nonlinearity affects the structure and the precision of the model after linearization, which will degrade the dynamic performance. So, a fractional order controller is addressed to eliminate the disturbance by adjusting the parameters which are added by the fractional order controller. Furthermore, the controller based on LQR is employed to compare with the fractional order controller. Finally, the performance of them is discussed by simulation. The results illustrated the validity of the fractional order controller.

Suspension tests on a larger scale. Report from the status seminar on magnetic suspension techniques. Testing of the electrodynamic system started

Energy Technology Data Exchange (ETDEWEB)

Rogg, D; Muckli, W

1976-07-01

A world record speed for electromagnetically suspended vehicles as well as successful suspension tests with forced-circulation cooled superconducting magnets were the outstanding success reports at the fifth status seminar 'Magnetic suspension techniques' on 31st March and 1st April in Bad Kissingen. The research work on magnetic suspension techniques in the railborne long-distance travel is supported by the Federal Ministry of Research and Technology (BMFT) within the frameworke of the programme 'Railway engineering - New technologies'.

Magnetic suspension characteristics of electromagnetic actuators

Science.gov (United States)

Rao, Dantam K.; Dill, J.; Zorzi, E.

1993-01-01

Electromagnetic actuators that use a current-carrying coil (which is placed in a magnetic field) to generate mechanical force are conceptually attractive components for active control of rotating shafts. In one concept that is being tested in the laboratory, the control forces from such actuators are applied on the flexibly supported bearing housings of the rotor. Development of this concept into a practical reality requires a clear and thorough understanding of the role of electromechanical parameters of these actuators in delivering the right amount of control force at the right phase into the rotor. The electromechanical parameters of the actuators investigated are the mass of the armature, stiffness of its suspension, electrical resistance, and inductance of the coils. Improper selection of these parameters can result in degradation in their performance, leading to mistuning between the actuator and the rotor. Through a simple analysis, it is shown that use of such mistuned actuators could result in sharp fluctuations in the phase of the control force delivered into the rotor around the critical speeds. These sharp fluctuations in phase, called 'Phase Glitches', are undesirable. Hence, future designs of controllers should take into account the undesirable mistuning effects between the actuator and the rotor caused by the phase glitches.

Four-Wheel Vehicle Suspension System

Science.gov (United States)

Bickler, Donald B.

1990-01-01

Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

Magnetic suspension and guidance of high speed vehicles. Final report

Energy Technology Data Exchange (ETDEWEB)

Alston, I A; Clark, J M; Hayden, J T

1972-12-01

Technical and economical assessments of magnetic suspensions for high speed vehicles and transport systems are reported. In these suspensions the suspending magnet takes the form of a powerful superconducting electromagnet that induces currents while it moves over conducting sheets or loops. A number of vehicle track designs are evaluated for operating cost effectiveness. It is shown that propulsion systems using power collected from the track are more expensive than those using power generated onboard the vehicle, and that the conducting sheet suspension is slightly more expensive than the null flux suspension.

Superconducting electromagnets for large wind tunnel magnetic suspension and balance systems

International Nuclear Information System (INIS)

Boom, R.W.; Abdelsalam, M.K.; Bakerek, K.

1985-01-01

This paper presents a new design study of a Magnetic Suspension and Balance System (MSBS) for airplane models in a large 8 ft x 8 ft wind tunnel. New developments in the design include: use of a superconducting solenoid as a model core instead of magnetized iron; combination of permanent magnet material in the model wings along with four race-track coils to produce the required roll torque; and mounting of all the magnets in an integral cold structure instead of in separate cryostats. Design of superconducting solenoid model cores and practical experience with a small-scale prototype are discussed

Techniques for extreme attitude suspension of a wind tunnel model in a magnetic suspension and balance system. Ph.D. Thesis

Science.gov (United States)

Parker, David Huw

1989-01-01

Although small scale magnetic suspension and balance systems (MSBSs) for wind tunnel use have been in existence for many years, they have not found general application in the production testing of flight vehicles. One reason for this is thought to lie in the relatively limited range of attitudes over which a wind tunnel model may be suspended. Modifications to a small MSBS to permit the suspension and control of axisymmetric models over angles of attack from less than zero to over ninety degrees are reported. Previous work has shown that existing arrangement of ten electromagnets was unable to generate one of the force components needed for control at extreme attitudes. Examination of possible solutions resulted in a simple alteration to rectify this deficiency. To generate the feedback signals to control the suspended model, an optical position sensing system using collimated laser beams and photodiode arrays was installed and tested. An analytical basis was developed for distributing the demands for force and moment needed for model stabilization amonge the electromagnets over the full attitude range. This was implemented by an MSBS control program able to continually adjust the distribution for the instantaneous incidence in accordance with prescheduled data. Results presented demonstrate rotations of models from zero to ninety degrees at rates up to ninety degrees per second, with pitching rates rising to several hundred degrees per second in response to step-change demands. A study of a design for a large MSBS suggests that such a system could be given the capability to control a model in six degrees of freedom over an unlimited angle of attack range.

49 CFR 570.8 - Suspension systems.

Science.gov (United States)

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Suspension systems. 570.8 Section 570.8 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or...

49 CFR 570.61 - Suspension system.

Science.gov (United States)

2010-10-01

... 49 Transportation 6 2010-10-01 2010-10-01 false Suspension system. 570.61 Section 570.61... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION VEHICLE IN USE INSPECTION STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.61 Suspension system. (a) Suspension condition. Ball joint seals shall not be cut...

Preliminary investigations of design philosophies and features applicable to large magnetic suspension and balance systems

Science.gov (United States)

Britcher, C. P.; Fortescue, P. W.; Allcock, G. A.; Goodyer, M. J.

1979-01-01

The technology which is required to allow the principles of magnetic suspension and balance systems (MSBS) to be applied to the high Reynolds number transonic testing of aircraft models is examined. A test facility is presented as comprising a pressurized transonic cryogenic wind tunnel, with the MSBS providing full six degree of freedom control. The electro-magnets which are superconducting and fed from quiet, bipolar power supplies are examined. A model control system having some self adaptive characteristics is discussed.

Electromagnetic Properties Analysis on Hybrid-driven System of Electromagnetic Motor

Science.gov (United States)

Zhao, Jingbo; Han, Bingyuan; Bei, Shaoyi

2018-01-01

The hybrid-driven system made of permanent-and electromagnets applied in the electromagnetic motor was analyzed, equivalent magnetic circuit was used to establish the mathematical models of hybrid-driven system, based on the models of hybrid-driven system, the air gap flux, air-gap magnetic flux density, electromagnetic force was proposed. Taking the air-gap magnetic flux density and electromagnetic force as main research object, the hybrid-driven system was researched. Electromagnetic properties of hybrid-driven system with different working current modes is studied preliminary. The results shown that analysis based on hybrid-driven system can improve the air-gap magnetic flux density and electromagnetic force more effectively and can also guarantee the output stability, the effectiveness and feasibility of the hybrid-driven system are verified, which proved theoretical basis for the design of hybrid-driven system.

Attractive and repulsive magnetic suspension systems overview

Science.gov (United States)

Cope, David B.; Fontana, Richard R.

1992-01-01

Magnetic suspension systems can be used in a wide variety of applications. The decision of whether to use an attractive or repulsive suspension system for a particular application is a fundamental one which must be made during the design process. As an aid to the designer, we compare and contrast attractive and repulsive magnetic suspension systems and indicate whether and under what conditions one or the other system is preferred.

Introducing Dual Suspension System in Road Vehicles

Directory of Open Access Journals (Sweden)

Imtiaz Hussain

2013-04-01

Full Text Available The main objective of suspension system is to reduce the motions of the vehicle body with respect to road disturbances. The conventional suspension systems in road vehicles use passive elements such as springs and dampers to suppress the vibrations induced by the irregularities in the road. But these conventional suspension systems can suppress vibrations to a certain limit. This paper presents a novel idea to improve the ride quality of roads vehicles without compromising vehicle?s stability. The paper proposes the use of primary and secondary suspension to suppress the vibrations more effectively.

49 CFR 393.207 - Suspension systems.

Science.gov (United States)

2010-10-01

... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2010-10-01 2010-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393...

Study on Dynamic Behaviour of Wishbone Suspension System

International Nuclear Information System (INIS)

Kamal, M; Rahman, M M

2012-01-01

This paper presents the characteristic model of the wishbone suspension system using the quarter car model approach. Suspension system in an automobile provides vehicle control and passenger comfort by providing isolation from road disturbances. This makes it essential that the detailed behavior of suspension should be known to optimize the performance. A kinetic study is performed using multi body system (MBS) analysis. The dirt road profile is considered as an applied loading. The spring constant, damping coefficient and sprung mass are studied on the performance of the suspension system. It can be observed that the spring constant is inversely related with time required to return to initial position and the amount of deformations. The damping ratio affects the suppression of spring oscillations, beyond a certain limit damping ration has the negligible effect. Sprung mass effected the equilibrium position of the suspension system with a small effect on its oscillation behavior. It is shown that the spring constant, damping ratio and sprung mass are significant parameters to design the suspension system. This study is essential for complete understanding of working of the suspension system and a future study with real geometries.

Analysis of Train Suspension System Using MR dampers

Science.gov (United States)

RamaSastry, DVA; Ramana, K. V.; Mohan Rao, N.; Siva Kumar, SVR; Priyanka, T. G. L.

2016-09-01

This paper deals with introducing MR dampers to the Train Suspension System for improving the ride comfort of the passengers. This type of suspension system comes under Semi-active suspension system which utilizes the properties of MR fluid to damp the vibrations. In case of high speed trains, the coach body is subjected to vibrations due to vertical displacement, yaw and pitch movements. When the body receives these disturbances from the ground,the transmission of vibrations to the passenger increases which affect the ride comfort. In this work, the equations of motion of suspension system are developed for both conventional passive system and semi-active system and are modelled in Matlab/Simulink and analysis has been carried out. The passive suspension system analysis shows that it is taking more time to damp the vibrations and at the same time the transmissibility of vibrations is more.Introducing MR dampers,vertical and angular displacements of the body are computed and compared. The results show that the introduction of MR dampers into the train suspension system improves ride comfort.

Introducing Dual Suspension System in Road Vehicles

OpenAIRE

Imtiaz Hussain; Jawaid Daudpoto; Ali Asghar Memon

2013-01-01

The main objective of suspension system is to reduce the motions of the vehicle body with respect to road disturbances. The conventional suspension systems in road vehicles use passive elements such as springs and dampers to suppress the vibrations induced by the irregularities in the road. But these conventional suspension systems can suppress vibrations to a certain limit. This paper presents a novel idea to improve the ride quality of roads vehicles without compromising vehicle?s stability...

Nonlinear Predictive Sliding Mode Control for Active Suspension System

Directory of Open Access Journals (Sweden)

Dazhuang Wang

2018-01-01

Full Text Available An active suspension system is important in meeting the requirements of the ride comfort and handling stability for vehicles. In this work, a nonlinear model of active suspension system and a corresponding nonlinear robust predictive sliding mode control are established for the control problem of active suspension. Firstly, a seven-degree-of-freedom active suspension model is established considering the nonlinear effects of springs and dampers; and secondly, the dynamic model is expanded in the time domain, and the corresponding predictive sliding mode control is established. The uncertainties in the controller are approximated by the fuzzy logic system, and the adaptive controller reduces the approximation error to increase the robustness of the control system. Finally, the simulation results show that the ride comfort and handling stability performance of the active suspension system is better than that of the passive suspension system and the Skyhook active suspension. Thus, the system can obviously improve the shock absorption performance of vehicles.

Development of A New Automotive Active Suspension System

Science.gov (United States)

Yousef Abdulhammed, Eng.; Eng. Hisham Elsherif, Dr, Prof.

2017-12-01

The main objective was to develop a smart new vehicle suspension system that minimizes the road irregularities impact on the driver, also to increase performance and stability of the vehicle at high speeds. The central idea is based on modifying the normal passive suspension system into a computer controller hydraulic actuated active suspension system simply by adding a new component such as a hydraulic cylinder on a normal passive system. The new suspension system is economical to be wildly used in consumer’s cars with low prices. The new added components was analytically tested and modeled according to different parameters. A new test rig was implemented to simulate a real quarter suspension system. The new suspension model was controlled by feedback controller according to the road conditions; the controller output controls the cylinder actuator to compensate the road oscillations and increases the vehicle stability for the passenger. Finally, to maximize the aerodynamics coefficients of the vehicle during high speeds by controlling the vehicle clearance level from the ground to achieve full stability, steering and fuel economy.

Design of a New Integrated Structure of the Active Suspension System and Emergency Lane Change Test

Science.gov (United States)

Zhao, Jing-bo; Liu, Hai-mei; Zhang, Lan-chun; Bei, Shao-yi

2017-09-01

An integrated structure of the active suspension system was proposed in order to solve the problem of the individual control of the height of the body or the adjustable damping of the active suspension system of the electric vehicle, which improve the vibration reduction performance of the vehicle. The air bag was used to replace the traditional spiral spring, and the traditional shock absorber was replaced by the damping adjustable shock absorber, and the control module received the body acceleration sensor and the horizontal height sensor signal. The system controlled adjustable damping coefficient of shock absorber through the height of the car body the output of the air pump relay and the height control valve and the output of the electromagnetic valve of the adjustable damping shock absorber, and the emergency lane change test was carried out under different modes of speed of 60km/h. The experimental results indicated that the damping value was greater, average roll angle, yaw angle and average vehicle lateral acceleration were small when vehicle body was in the state of emergency lane change, which verified the feasibility of the integrated control strategy and structure design of the active suspension system. The research has important theoretical research value and engineering application prospect for designing and controlling strategy of vehicle chassis integrated control system.

Experimental Evaluation of Mountain Bike Suspension Systems

Directory of Open Access Journals (Sweden)

J. Titlestad

2003-01-01

Full Text Available A significant distinction between competitive mountain bikes is whether they have a suspension system. Research studies indicate that a suspension system gives advantages, but it is difficult to quantify the benefits because they depend on so many variables, including the physiology and psychology of the cyclist, the roughness of the track and the design of the suspension system. A laboratory based test rig has been built that allows the number of variables in the system to be reduced and test conditions to be controlled. The test rig simulates regular impacts of the rear wheel with bumps in a rolling road. The physiological variables of oxygen consumption and heart rate were measured, together with speeds and forces at various points in the system. Physiological and mechanical test results both confirm a significant benefit in using a suspension system on the simulated rough track, with oxygen consumption reduced by around 30 % and power transmitted through the pedals reduced by 30 % to 60 %.

Intelligent systems of the vehicles’ suspension

Science.gov (United States)

Yurlin, D.

2018-02-01

The article is devoted to the current condition of car’s active suspension system. It presents the tendencies in development of the active systems of suspension system, adjustable elements incorporated in them and the companies succeeded in designing such systems. It also mirrors the problem of impact of active systems on car’s safety and their importance for the driver. Advantages and disadvantages of the most common types of active elements are being described, analyzed and compared. The author concludes about the perspectives of these systems’ development.

Optimal Vibration Control for Tracked Vehicle Suspension Systems

Directory of Open Access Journals (Sweden)

Yan-Jun Liang

2013-01-01

Full Text Available Technique of optimal vibration control with exponential decay rate and simulation for vehicle active suspension systems is developed. Mechanical model and dynamic system for a class of tracked vehicle suspension vibration control is established and the corresponding system of state space form is described. In order to prolong the working life of suspension system and improve ride comfort, based on the active suspension vibration control devices and using optimal control approach, an optimal vibration controller with exponential decay rate is designed. Numerical simulations are carried out, and the control effects of the ordinary optimal controller and the proposed controller are compared. Numerical simulation results illustrate the effectiveness of the proposed technique.

Characteristics of persistent-current mode of HTS coil on superconducting electromagnet

International Nuclear Information System (INIS)

Lee, C.Y.; Kim, J.; Han, Y.J.; Kang, B.; Chung, Y.D.; Yoon, Y.S.; Chu, S.Y.; Hwang, Y.J.; Jo, H.C.; Jang, J.Y.; Ko, T.K.

2011-01-01

The levitation gap of an electromagnetic suspension (EMS) system affects the current decay rate of superconducting electromagnet. The presence of iron core provides a significant benefit in the PCM performance of SC coil. The increased levitation gap of the EMS model with the SC-EM could negatively affect the design of SC-EM operated in PCM. This paper investigates the way in which the levitation gap of an electromagnetic suspension (EMS) system affects the current decay rate of superconducting electromagnet (SC-EM) operated in persistence-current mode (PCM). Using inductance analyzed from the magnetic circuit of an EMS model, the current decay rate caused by the variation in the levitation gap was simulated. In order to experimentally verify the simulation results, we fabricated a small-scale EMS model with SC coil operated in PCM and measured the current decay rates at different levitation gaps. The result showed that the presence of iron core provides a significant benefit in the PCM performance of SC coil, but the benefit decreased as the levitation gap increases. This study revealed that the increased levitation gap of the EMS model with the SC-EM could negatively affect the design of SC-EM operated in PCM.

System and technique for ultrasonic characterization of settling suspensions

Energy Technology Data Exchange (ETDEWEB)

Greenwood, Margaret S [Richland, WA; Panetta, Paul D [Richland, WA; Bamberger, Judith A [Richland, WA; Pappas, Richard A [Richland, WA

2006-11-28

A system for determining properties of settling suspensions includes a settling container, a mixer, and devices for ultrasonic interrogation transverse to the settling direction. A computer system controls operation of the mixer and the interrogation devices and records the response to the interrogating as a function of settling time, which is then used to determine suspension properties. Attenuation versus settling time for dilute suspensions, such as dilute wood pulp suspension, exhibits a peak at different settling times for suspensions having different properties, and the location of this peak is used as one mechanism for characterizing suspensions. Alternatively or in addition, a plurality of ultrasound receivers are arranged at different angles to a common transmitter to receive scattering responses at a variety of angles during particle settling. Angular differences in scattering as a function of settling time are also used to characterize the suspension.

A System for Electromagnetic Field Conversion

DEFF Research Database (Denmark)

2003-01-01

A system is provided for conversion of a first electromagnetic field into a desired second electromagnetic field, for example for coupling modes between waveguides or into microstructured waveguides. The system comprises a complex spatial electromagnetic field converter that is positioned...... for reception of at least a part of the first electromagnetic field and that is adapted for conversion of the received field into the desired electromagnetic field, and wherein at least one of the first and second fields matches a mode of a microstructured waveguide. It is an important advantage of the present...

Design of a suspension system and determining suspension parameters of a medium downforce small Formula type car

Directory of Open Access Journals (Sweden)

Biswal Sadjyot

2017-01-01

Full Text Available The focus of the paper is on designing a suspension system for a medium downforce small Formula type race car. The paper not only focusses on step by step design for a double wishbone type suspension but will also show the use and role of kinematics software in determining the optimized suspension of the car. The paper will also focus on the use of tire data in determining suspension parameters and the design of the double wishbone suspension. Various parameters, their design importance and the process to optimize them according to suspension design goals will be covered. The easiest and best ways to change the suspension parameters to get the best results will also be covered.

A universal suspension test rig for electrohydraulic active and passive automotive suspension system

Directory of Open Access Journals (Sweden)

Mahmoud Omar

2017-12-01

Full Text Available A fully active electro-hydraulic and passive automotive quarter car suspensions with their experimental test-rigs are designed and implemented. Investigation of the active performance compared against the passive is performed experimentally and numerically utilizing SIMULINK's Simscape library. Both systems are modeled as single-degree-of-freedom in order to simplify the validation process. Economic considerations were considered during the rig's implementation. The rig consists of two identical platforms fixed side by side allowing testing two independent suspensions simultaneously. Position sensors for sprung and unsprung masses on both platforms are installed. The road input is introduced by a cam and a roller follower mechanism driven by 1.12 kW single phase induction motor with speed reduction assembly. The active hydraulic cylinder was the most viable choice due to its high power-to-weight ratio. The active control is of the proportional-integral-differential (PID type. Though this technique is quite simple and not new, yet the emphasis of this paper is the engineering, design and implementation of the experimental setup and controller. A successful validation process is performed. Ride comfort significantly improved with active suspension, as shown by the results; 24.8% sprung mass vibration attenuation is achieved. The details of the developed system with the analytical and experimental results are presented. Keywords: Active suspension, Passive suspension, Servo, Hydraulic, Control, PID

Heliborne time domain electromagnetic system

International Nuclear Information System (INIS)

Bhattacharya, S.

2009-01-01

Atomic Minerals Directorate (AMD), are using heliborne and ground time domain electromagnetic (TDEM) system for the exploration of deep seated unconformity type uranium deposits. Uranium has been explored in various parts of the world like Athabasca basin using time domain electromagnetic system. AMD has identified some areas in India where such deposits are available. Apart from uranium exploration, the TDEM systems are used for the exploration of deep seated minerals like diamonds. Bhabha Atomic Research Centre (BARC) is involved in the indigenous design of the heliborne time domain system since this system is useful for DAE and also it has a scope of wide application. In this paper we discuss about the principle of time domain electromagnetic systems, their capabilities and the development and problems of such system for various other mineral exploration. (author)

15 CFR 2011.207 - Suspension of the certificate system.

Science.gov (United States)

2010-01-01

..., SYRUPS AND MOLASSES Specialty Sugar § 2011.207 Suspension of the certificate system. (a) Suspension. The.... Notice of such suspension and the effective date thereof shall be published in the Federal Register. (b... such reinstatement and the effective date thereof shall be published in the Federal Register. (c...

Design and analysis of an intelligent controller for active geometry suspension systems

Science.gov (United States)

Goodarzi, Avesta; Oloomi, Ehsan; Esmailzadeh, Ebrahim

2011-02-01

An active geometry suspension (AGS) system is a device to optimise suspension-related factors such as toe angle and roll centre height by controlling vehicle's suspension geometry. The suspension geometry could be changed through control of suspension mounting point's position. In this paper, analysis and control of an AGS system is addressed. First, the effects of suspension geometry change on roll centre height and toe angle are studied. Then, based on an analytical approach, the improvement of the vehicle's stability and handling due to the control of suspension geometry is investigated. In the next section, an eight-degree-of-freedom handling model of a sport utility vehicle equipped with an AGS system is introduced. Finally, a self-tuning proportional-integral controller has been designed, using the fuzzy control theory, to control the actuator that changes the geometry of the suspension system. The simulation results show that an AGS system can improve the handling and stability of the vehicle.

Realistic control considerations for electromagnetically levitated urban transit vehicles

Energy Technology Data Exchange (ETDEWEB)

Billing, J R

1976-04-01

A discussion is given of realistic control considerations of suspension dynamics and vehicle/guideway interaction for electromagnetically-levitated urban transit vehicles in the context of revenue applications. The emphasis is on safety, reliability, and maintainability rather than performance. An example urban transit system is described, and the following considerations of dynamics and control are examined: stability, magnet force requirements, magnet airgap requirements, vehicle ride, and component failures. It is shown that it is a formidable problem to ensure suspension stability under all conditions; that operation on curves is a critical magnet and control system design case; that operation of the magnets in the non-linear regime is unavoidable and that component failures will be a major problem. However, good vehicle ride is to be expected. It is concluded that magnetic levitation suspension technology requires substantial development effort before it can be considered suitable for revenue operation.

Electromagnetic interference in electrical systems of motor vehicles

Science.gov (United States)

Dziubiński, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

2016-09-01

Electronic ignition system affects the electronic equipment of the vehicle by electric and magnetic fields. The measurement of radio electromagnetic interference originating from the ignition system affecting the audiovisual test bench was carried out with a variable speed of the ignition system. The paper presents measurements of radio electromagnetic interference in automobiles. In order to determine the level of electromagnetic interference, the audiovisual test bench was equipped with a set of meters for power consumption and assessment of the level of electromagnetic interference. Measurements of the electromagnetic interference level within the audiovisual system were performed on an experimental test bench consisting of the ignition system, starting system and charging system with an alternator and regulator.

Research into the Effect of Supercapacitor Terminal Voltage on Regenerative Suspension Energy-Regeneration and Dynamic Performance

Directory of Open Access Journals (Sweden)

Ruochen Wang

2017-01-01

Full Text Available To study the effect of supercapacitor initial terminal voltage on the regenerative and semiactive suspension energy-regeneration and dynamic performance, firstly, the relationship between supercapacitor terminal voltage and linear motor electromagnetic damping force and that between supercapacitor terminal voltage and recycled energy by the supercapacitor in one single switching period were both analyzed. The result shows that the linear motor electromagnetic damping force is irrelevant to the supercapacitor terminal voltage, and the recycled energy by the supercapacitor reaches the maximum when initial terminal voltage of the supercapacitor equals output terminal voltage of the linear motor. Then, performances of system dynamics and energy-regeneration were studied as the supercapacitor initial terminal voltage varied in situations of B level and C level road. The result showed that recycled energy by the supercapacitor increased at first and then decreased while the dynamic performance had no obvious change. On the basis of previous study, a mode-switching control strategy of supercapacitor for the regenerative and semiactive suspension system was proposed, and the mode-switching rule was built. According to simulation and experiment results, the system energy-regeneration efficiency can be increased by utilizing the control strategy without influencing suspension dynamic performance, which is highly valuable to practical engineering.

Analysis of a front suspension system for UniART FSAE car using FEA

Science.gov (United States)

Zaidie, M. N. A.; Hashim, M. S. M.; Tasyrif, M.; Basha, M. H.; Ibrahim, I.; Kamaruddin, N. S.; Shahriman, A. B.

2017-10-01

In recent years, many research works from institutions that participated in Formula SAE had highlighted on suspension systems. The aim is to improve the system in term of performance and robustness. However, every suspension system for a racing car is tailored to the car itself. Thus, this paper proposes a new design for front suspension system for UniART FSAE car. The new design was than being compared to the previous suspension system for enhancement. The analysis covered in this paper based on several conditions such as braking, cornering and bumping condition and was carried out using finite element analysis. Each main component for the suspension system such as lower arm, upper arm and knuckle has been analysed in term of strength and performance. From the results, the proposed new design of the suspension system has improved in term of strength and performance compared to the previous suspension system.

A Kinematic, Kevlar(registered) Suspension System for an ADR

Science.gov (United States)

Voellmer, George M.; Jackson, Michael L.; Shirron, Peter J.; Tuttle, James G.

2003-01-01

The High Resolution Airborne Wideband Camera (HAWC) and the Submillimeter And Far Infrared Experiment (SAFIRE) will use identical Adiabatic Demagnetization Refrigerators (ADR) to cool their bolometer detectors to 200mK and 100mK, respectively. In order to minimize thermal loads on the salt pill, a Kevlar@ suspension system is used to hold it in place. An innovative, kinematic suspension system is presented. The suspension system is unique in that it consists or two parts that can be assembled and tensioned offline, and later bolted onto the salt pill. The resulting assembly constrains each degree of freedom only once, yielding a kinematic, tensile structure.

MEMS mass-spring-damper systems using an out-of-plane suspension scheme

KAUST Repository

Abdel Aziz, Ahmed Kamal Said; Sharaf, Abdel Hameed; Serry, Mohamed Yousef; Sedky, Sherif Salah

2014-01-01

MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

MEMS mass-spring-damper systems using an out-of-plane suspension scheme

KAUST Repository

Abdel Aziz, Ahmed Kamal Said

2014-02-04

MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) using an out-of-plane (or vertical) suspension scheme, wherein the suspensions are normal to the proof mass, are disclosed. Such out-of-plane suspension scheme helps such MEMS mass-spring-damper systems achieve inertial grade performance. Methods of fabricating out-of-plane suspensions in MEMS mass-spring-damper systems (including MEMS gyroscopes and accelerometers) are also disclosed.

15 CFR 2011.110 - Suspension of certificate system.

Science.gov (United States)

2010-01-01

..., SYRUPS AND MOLASSES Certificate of Quota Eligibility § 2011.110 Suspension of certificate system. (a... of such suspension and the effective date thereof shall be published in the Federal Register. (b... such reinstatement and the effective date thereof shall be published in the Federal Register. (c...

The electromagnetic and acoustic properties of smoke particulates

International Nuclear Information System (INIS)

Churches, D.K.

1999-10-01

The research work explores the Electromagnetic and Acoustic Properties of Smoke Particulates from real fires, and the initial development of an alternative method of smoke detection based on the study work. The research was entirely self-funded including the purchase of the experimental apparatus, test equipment and calibration to international standards. The study includes the properties of solid and liquid post combustion particulates in air suspension forming smoke plumes, and the associated fluid flow dynamics. As part of the study the electromagnetic and acoustic properties of smoke particulates, a somewhat unique detection method described as the ''Double Matrix Board System'' was developed and used. It was initially developed to assist in the electromagnetic study work, and was later modified to examine the acoustic properties. The published results of the research on the ''Double Matrix Board System'' and the details of the patent application for the device are included in the Appendices to the Thesis document. (author)

Computation of magnetic suspension of maglev systems using dynamic circuit theory

Science.gov (United States)

He, J. L.; Rote, D. M.; Coffey, H. T.

1992-01-01

Dynamic circuit theory is applied to several magnetic suspensions associated with maglev systems. These suspension systems are the loop-shaped coil guideway, the figure-eight-shaped null-flux coil guideway, and the continuous sheet guideway. Mathematical models, which can be used for the development of computer codes, are provided for each of these suspension systems. The differences and similarities of the models in using dynamic circuit theory are discussed in the paper. The paper emphasizes the transient and dynamic analysis and computer simulation of maglev systems. In general, the method discussed here can be applied to many electrodynamic suspension system design concepts. It is also suited for the computation of the performance of maglev propulsion systems. Numerical examples are presented in the paper.

Effect of the crone suspension control system on braking

Energy Technology Data Exchange (ETDEWEB)

Moreau, X.; Oustaloup, A. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique; Nouillant, C. [Bordeaux-1 Univ., Talence (France). Lab. d' Automatique et de Productique]|[DRIA-PSA Peugeot Citroen, Velizy - Villacoublay (France)

2001-07-01

Semi-active or active suspensions not only increase driving comfort, but also permit the control system to be switched over if required in order to improve the transmission of forces at the points of contact between tire and road surface by minimizing the dynamic wheel loads. It may also be possible to use these systems to control wheel load distribution and, thus, influence braking or steering performance by changing the distribution of normal forces between the front and rear axles. This article examines the effect of the CRONE suspension control system on braking. The central idea is to use continuously variable dampers and fast load levelling devices to distribute the normal forces of tire between the front and rear axles. The basis principle is explained using known dynamic properties of active suspension, vehicles and tires. The effect of active suspension on vehicle response during braking is then evaluated using computer simulations from a two-wheel vehicle model. (orig.)

A microsphere suspension model of metamaterial fluids

Directory of Open Access Journals (Sweden)

Qian Duan

2017-05-01

Full Text Available Drawing an analogy to the liquid phase of natural materials, we theoretically propose a microsphere suspension model to realize a metamaterial fluid with artificial electromagnetic indexes. By immersing high-ε, micrometer-sized dielectric spheres in a low-ε insulating oil, the structured fluid exhibits liquid-like properties from dispersing phase as well as the isotropic negative electromagnetic parameters caused by Mie resonances from dispersed microspheres. The work presented here will benefit the development of structured fluids toward metamaterials.

Adaptive tracking control for active suspension systems with non-ideal actuators

Science.gov (United States)

Pan, Huihui; Sun, Weichao; Jing, Xingjian; Gao, Huijun; Yao, Jianyong

2017-07-01

As a critical component of transportation vehicles, active suspension systems are instrumental in the improvement of ride comfort and maneuverability. However, practical active suspensions commonly suffer from parameter uncertainties (e.g., the variations of payload mass and suspension component parameters), external disturbances and especially the unknown non-ideal actuators (i.e., dead-zone and hysteresis nonlinearities), which always significantly deteriorate the control performance in practice. To overcome these issues, this paper synthesizes an adaptive tracking control strategy for vehicle suspension systems to achieve suspension performance improvements. The proposed control algorithm is formulated by developing a unified framework of non-ideal actuators rather than a separate way, which is a simple yet effective approach to remove the unexpected nonlinear effects. From the perspective of practical implementation, the advantages of the presented controller for active suspensions include that the assumptions on the measurable actuator outputs, the prior knowledge of nonlinear actuator parameters and the uncertain parameters within a known compact set are not required. Furthermore, the stability of the closed-loop suspension system is theoretically guaranteed by rigorous mathematical analysis. Finally, the effectiveness of the presented adaptive control scheme is confirmed using comparative numerical simulation validations.

Operational Modal Analysis and the Performance Assessment of Vehicle Suspension Systems

Directory of Open Access Journals (Sweden)

L. Soria

2012-01-01

Full Text Available Comfort, road holding and safety of passenger cars are mainly influenced by an appropriate design of suspension systems. Improvements of the dynamic behaviour can be achieved by implementing semi-active or active suspension systems. In these cases, the correct design of a well-performing suspension control strategy is of fundamental importance to obtain satisfying results. Operational Modal Analysis allows the experimental structural identification in those that are the real operating conditions: Moving from output-only data, leading to modal models linearised around the more interesting working points and, in the case of controlled systems, providing the needed information for the optimal design and verification of the controller performance. All these characters are needed for the experimental assessment of vehicle suspension systems. In the paper two suspension architectures are considered equipping the same car type. The former is a semi-active commercial system, the latter a novel prototypic active system. For the assessment of suspension performance, two different kinds of tests have been considered, proving ground tests on different road profiles and laboratory four poster rig tests. By OMA-processing the signals acquired in the different testing conditions and by comparing the results, it is shown how this tool can be effectively utilised to verify the operation and the performance of those systems, by only carrying out a simple, cost-effective road test.

A novel magnetic lead screw active suspension system for vehicles

DEFF Research Database (Denmark)

Berg, Nick Ilsø; Holm, Rasmus Koldborg; Rasmussen, Peter Omand

2014-01-01

This paper encompasses a detailed study of the redesign of a novel Magnetic Lead Screw (MLS) active suspension system for possible regeneration of the energy dispatched in the suspension system and active control of vehicle body movement. The MLS converts a low speed high force linear motion...... of a translator into a high speed low torque rotational motion of a rotor through helically shaped magnets. The paper describes the drawback of the first MLS prototype v1.0 developed for active suspension system, which lead to a new design of the MLS prototype named v1.5. Furthermore the paper introduces detailed...

Fuzzy-Skyhook Control for Active Suspension Systems Applied to a Full Vehicle Model

Directory of Open Access Journals (Sweden)

Aref M.A. Soliman

2012-04-01

Full Text Available Nowadays, most modern vehicles are equipped with controlled suspension systems for improving the vehicle ride comfort. Therefore, this paper is concerned with a theoretical study for the ride comfort performance of the vehicle. The theoretical investigation includes a suggestion of an active suspension system controller using fuzzy-skyhook control theory, which offers new opportunities for the improvement of vehicle ride performance. The ride comfort of the active suspension system has been evaluated using a 7 degree of freedom full vehicle mathematical model. The simulation results are presented in the time and frequency domain, also in terms of RMS values, and it’s shown that the proposed active suspension system with fuzzy-skyhook control improved the vehicle ride quality in terms of body acceleration, suspension working space and dynamic tyre load in comparison with the passive and skyhook suspension systems.

A new variable stiffness suspension system: passive case

Directory of Open Access Journals (Sweden)

O. M. Anubi

2013-02-01

Full Text Available This paper presents the design, analysis, and experimental validation of the passive case of a variable stiffness suspension system. The central concept is based on a recently designed variable stiffness mechanism. It consists of a horizontal control strut and a vertical strut. The main idea is to vary the load transfer ratio by moving the location of the point of attachment of the vertical strut to the car body. This movement is controlled passively using the horizontal strut. The system is analyzed using an L2-gain analysis based on the concept of energy dissipation. The analyses, simulation, and experimental results show that the variable stiffness suspension achieves better performance than the constant stiffness counterpart. The performance criteria used are; ride comfort, characterized by the car body acceleration, suspension deflection, and road holding, characterized by tire deflection.

Development of an Air Pneumatic Suspension System for Transtibial Prostheses

Directory of Open Access Journals (Sweden)

Gholamhossein Pirouzi

2014-09-01

Full Text Available The suspension system and socket fitting of artificial limbs have major roles and vital effects on the comfort, mobility, and satisfaction of amputees. This paper introduces a new pneumatic suspension system that overcomes the drawbacks of current suspension systems in donning and doffing, change in volume during daily activities, and pressure distribution in the socket-stump interface. An air pneumatic suspension system (APSS for total-contact sockets was designed and developed. Pistoning and pressure distribution in the socket-stump interface were tested for the new APSS. More than 95% of the area between each prosthetic socket and liner was measured using a Tekscan F-Scan pressure measurement which has developed matrix-based pressure sensing systems. The variance in pressure around the stump was 8.76 kPa. APSS exhibits less pressure concentration around the stump, improved pressure distribution, easy donning and doffing, adjustability to remain fitted to the socket during daily activities, and more adaptability to the changes in stump volume. The volume changes were adjusted by utility of air pressure sensor. The vertical displacement point and reliability of suspension were assessed using a photographic method. The optimum pressure in every level of loading weight was 55 kPa, and the maximum displacement was 6 mm when 90 N of weight was loaded.

Vibration control of an energy regenerative seat suspension with variable external resistance

Science.gov (United States)

Ning, Donghong; Sun, Shuaishuai; Du, Haiping; Li, Weihua; Zhang, Nong

2018-06-01

In this paper, an energy regenerative seat suspension with a variable external resistance is proposed and built, and a semi-active controller for its vibration control is also designed and validated. The energy regenerative seat suspension is built with a three-phase generator and a gear reducer, which are installed in the scissors structure centre of the seat suspension, and the vibration energy is directly harvested from the rotary movement of suspension's scissors structure. The electromagnetic torque of the semi-active seat suspension actuator is controlled by an external variable resistor. An integrated model including the seat suspension's kinematics and the generator is built and proven to match the test result very well. A simplified experimental phenomenon model is also built based on the test results for the controller design. A state feedback H∞ controller is proposed for the regenerative seat suspension's semi-active vibration control. The proposed regenerative seat suspension and its controller are validated with both simulations and experiments. A well-tuned passive seat suspension is applied to evaluate the regenerative seat's performance. Based on ISO 2631-1, the frequency-weighted root mean square (FW-RMS) acceleration of the proposed seat suspension has a 22.84% reduction when compared with the passive one, which indicates the improvement of ride comfort. At the same time, the generated RMS power is 1.21 W. The proposed regenerative seat suspension can greatly improve the driver's ride comfort and has the potential to be developed to a self-powered semi-active system.

A magnetic suspension system for measuring liquid density

Directory of Open Access Journals (Sweden)

Luz María Centeno González

2013-01-01

Full Text Available Density is a derived quantity of mass and length; it is defined as mass per volume unit and its SI unit is kg/m3. National metrology institutes have been designing and building their own magnetic suspension systems during the last 5 decades for making fluid density measurements; this has allowed them to carry out research into liquids and gases’ physical characteristics. This paper was aimed at designing and developing a magnetic suspension system for a magnetic balance used in determining liquid density to be used in CENAM’s metrology density laboratories.

Vibration Reduction System Using Magnetic Suspension Technology

Directory of Open Access Journals (Sweden)

Spychała Jarosław

2015-01-01

Full Text Available The article presents considerations concerning the construction of vibration reduction system using magnetic suspension technology. Presents the results of simulation, numerical and experimental the bearingless electric motor, for which successfully used this type of solution. Positive results of research and testing have become the basis for the development of the concept of building this type of active vibration reduction system , at the same time acting as a support for a technical object, which is a jet engine. Bearing failures are manifested by loss or distortion of their mass, which leads to a total destruction of the roller bearing, and thus reflected in the security. The article presents the concept of building active magnetic suspension to eliminate the bearing system of classical rolling bearing and replace it with magnetic bearing.

Two-Dimensional Fuzzy Sliding Mode Control of a Field-Sensed Magnetic Suspension System

Directory of Open Access Journals (Sweden)

Jen-Hsing Li

2014-01-01

Full Text Available This paper presents the two-dimensional fuzzy sliding mode control of a field-sensed magnetic suspension system. The fuzzy rules include both the sliding manifold and its derivative. The fuzzy sliding mode control has advantages of the sliding mode control and the fuzzy control rules are minimized. Magnetic suspension systems are nonlinear and inherently unstable systems. The two-dimensional fuzzy sliding mode control can stabilize the nonlinear systems globally and attenuate chatter effectively. It is adequate to be applied to magnetic suspension systems. New design circuits of magnetic suspension systems are proposed in this paper. ARM Cortex-M3 microcontroller is utilized as a digital controller. The implemented driver, sensor, and control circuits are simpler, more inexpensive, and effective. This apparatus is satisfactory for engineering education. In the hands-on experiments, the proposed control scheme markedly improves performances of the field-sensed magnetic suspension system.

Progress of magnetic-suspension systems and magnetic bearings in the USSR

International Nuclear Information System (INIS)

Kuzin, A.V.

1992-01-01

This paper traces the development and progress of magnetic suspension systems and magnetic bearings in the USSR. The paper describes magnetic bearings for turbomachines, magnetic suspension systems for vibration isolation, some special measuring devices, wind tunnels, and other applications. The design, principles of operation, and dynamic characteristics of the system are presented

Development of a non-piston MR suspension rod for variable mass systems

Science.gov (United States)

Deng, Huaxia; Han, Guanghui; Zhang, Jin; Wang, Mingxian; Ma, Mengchao; Zhong, Xiang; Yu, Liandong

2018-06-01

The semi-active suspension systems for variable mass systems require long work stroke and variable damping, while the currently piston structure limits the work stroke for the magnetorheological (MR) dampers. The main work of this paper is to design a semi-active non-piston MR (NPMR) suspension rod for the reduction of the vibration of an automatic impeller washing machine, which is a typical variable mass system. The designed suspension rod locates in the suspension system that links the internal tub to the washing machine cabinet. The NPMR suspension rod includes a MR part and a air part. The MR part can provide low initial damping force and the unlimited work stroke compared with the piston MR damper. The hysteretic response tests and vibration performance evaluation with different loadings are conducted to verify the dynamic performance for the designed rod. The measured damping force of the MR part varies from 5 to 20 N. Studies of dehydration mode experiments of the washing machine indicate that its vibration acceleration with the NPMR suspension rods can reduce to half of the original passive ones in certain conditions.

Neural control of magnetic suspension systems

Science.gov (United States)

Gray, W. Steven

1993-01-01

The purpose of this research program is to design, build and test (in cooperation with NASA personnel from the NASA Langley Research Center) neural controllers for two different small air-gap magnetic suspension systems. The general objective of the program is to study neural network architectures for the purpose of control in an experimental setting and to demonstrate the feasibility of the concept. The specific objectives of the research program are: (1) to demonstrate through simulation and experimentation the feasibility of using neural controllers to stabilize a nonlinear magnetic suspension system; (2) to investigate through simulation and experimentation the performance of neural controllers designs under various types of parametric and nonparametric uncertainty; (3) to investigate through simulation and experimentation various types of neural architectures for real-time control with respect to performance and complexity; and (4) to benchmark in an experimental setting the performance of neural controllers against other types of existing linear and nonlinear compensator designs. To date, the first one-dimensional, small air-gap magnetic suspension system has been built, tested and delivered to the NASA Langley Research Center. The device is currently being stabilized with a digital linear phase-lead controller. The neural controller hardware is under construction. Two different neural network paradigms are under consideration, one based on hidden layer feedforward networks trained via back propagation and one based on using Gaussian radial basis functions trained by analytical methods related to stability conditions. Some advanced nonlinear control algorithms using feedback linearization and sliding mode control are in simulation studies.

Narrow field electromagnetic sensor system and method

International Nuclear Information System (INIS)

McEwan, T.E.

1996-01-01

A narrow field electromagnetic sensor system and method of sensing a characteristic of an object provide the capability to realize a characteristic of an object such as density, thickness, or presence, for any desired coordinate position on the object. One application is imaging. The sensor can also be used as an obstruction detector or an electronic trip wire with a narrow field without the disadvantages of impaired performance when exposed to dirt, snow, rain, or sunlight. The sensor employs a transmitter for transmitting a sequence of electromagnetic signals in response to a transmit timing signal, a receiver for sampling only the initial direct RF path of the electromagnetic signal while excluding all other electromagnetic signals in response to a receive timing signal, and a signal processor for processing the sampled direct RF path electromagnetic signal and providing an indication of the characteristic of an object. Usually, the electromagnetic signal is a short RF burst and the obstruction must provide a substantially complete eclipse of the direct RF path. By employing time-of-flight techniques, a timing circuit controls the receiver to sample only the initial direct RF path of the electromagnetic signal while not sampling indirect path electromagnetic signals. The sensor system also incorporates circuitry for ultra-wideband spread spectrum operation that reduces interference to and from other RF services while allowing co-location of multiple electronic sensors without the need for frequency assignments. 12 figs

Magnetic suspension of a rotating system. Application to inertial flywheels

International Nuclear Information System (INIS)

Lemarquand, Guy

1984-01-01

The various possible magnetic suspension configurations compatible with rotating mechanical systems are defined from studies of the characteristics of different types of magnetic bearings. The results obtained are used in the design and realization of a magnetic suspension for an inertial flywheel. (author) [fr

Dynamics of Solid Body in Magnetic Suspension under Periodic Excitation

Directory of Open Access Journals (Sweden)

A. M. Gouskov

2017-01-01

Full Text Available The article studies dynamics of ferromagnetic body in hybrid magnetic suspension (HMS. The body is supposed to have one degree of freedom and a nonlinear magnetic force dependence on the current and displacement. The magnetic force induced in the HMS is divided into a passive component and an active one. Specifying the law of current variation in the coil allows us to generate nonlinear oscillations under electromagnet action. To provide periodic excitation the appropriate law of the current variation in the electromagnet coil is proposed. The mathematical model includes external periodic step-excitation. The equation of motion is formed. The scales of similarity are highlighted in the system, and the equation of motion is reduced to dimensionless form.The motion dynamics is studied numerically. The relaxation method was used to determine the periodic motions at different values of dimensionless frequency of the electromagnet excitation as well as to estimate the influence of other dimensionless parameters on the system dynamics. The amplitude-frequency curve analysis allows us to come to conclusion that the nature of system nonlinearity is rigid. Adding the external periodic step-excitation leads to the qualitative change in the nature of movement. This points to the occurrence of bifurcation.

Analysis of the Kinematics and Compliance of a Passive Suspension System using Adams Car

Directory of Open Access Journals (Sweden)

N. Ikhsan

2015-06-01

Full Text Available The experimental approach is usually used as the way to develop or modify a suspension system to obtain maximum ride comfort and handling characteristics. This approach is a time-consuming process, costly, and may not guarantee the optimum solution. Thus, to avoid this, a virtual vehicle suspension system is necessary. In this paper, a half-car body of an actual suspension system based on the PROTON WRM 44 P0-34 was modeled and simulated. In total, 10 components comprised each front McPherson strut and rear multilink suspension consisting of different joint types and a number of degrees of freedom. The model was developed by defining the location of the hard point or coordinate before specifying the component characteristics and joint type. The completed suspension model was simulated using the vertical parallel and vertical oppose movement test, the same tests conducted with the actual experimental parameter setup. The kinematics and compliance (K&C of the simulation is compared with the experimental data to verify the suspension model. The outcome from the simulation showed a verified virtual suspension system model with a very minimum percentage of error and different characteristics of the static performance of the suspension system when subjected to the test as explained further in the paper.

Magnetic suspension motorized spindle-cutting system dynamics analysis and vibration control review

Directory of Open Access Journals (Sweden)

Xiaoli QIAO

2016-10-01

Full Text Available The performance of high-speed spindle directly determines the development of high-end machine tools. The cutting system's dynamic characteristics and vibration control effect are inseparable with the performance of the spindle,which influence each other, synergistic effect together the cutting efficiency, the surface quality of the workpiece and tool life in machining process. So, the review status on magnetic suspension motorized spindle, magnetic suspension bearing-flexible rotor system dynamics modeling theory and status of active control technology of flexible magnetic suspension motorized spindle rotor vibration are studied, and the problems which present in the magnetic suspension flexible motorized spindle rotor systems are refined, and the development trend of magnetic levitation motorized spindle and the application prospect is forecasted.

Design and analysis of the SSC [Superconducting Super Collider] dipole magnet suspension system

International Nuclear Information System (INIS)

Nicol, T.H.; Niemann, R.C.; Gonczy, J.D.

1989-03-01

The design of the suspension system for Superconducting Super Collider (SSC) dipole magnets has been driven by rigorous thermal and structural requirements. The current system, designed to meet those requirements, represents a significant departure from previous superconducting magnet suspension system designs. This paper will present a summary of the design and analysis of the vertical and lateral suspension as well as the axial anchor system employed in SSC dipole magnets. 5 refs., 9 figs., 4 tabs

Optical demodulation system for digitally encoded suspension array in fluoroimmunoassay

Science.gov (United States)

He, Qinghua; Li, Dongmei; He, Yonghong; Guan, Tian; Zhang, Yilong; Shen, Zhiyuan; Chen, Xuejing; Liu, Siyu; Lu, Bangrong; Ji, Yanhong

2017-09-01

A laser-induced breakdown spectroscopy and fluorescence spectroscopy-coupled optical system is reported to demodulate digitally encoded suspension array in fluoroimmunoassay. It takes advantage of the plasma emissions of assembled elemental materials to digitally decode the suspension array, providing a more stable and accurate recognition to target biomolecules. By separating the decoding procedure of suspension array and adsorption quantity calculation of biomolecules into two independent channels, the cross talk between decoding and label signals in traditional methods had been successfully avoided, which promoted the accuracy of both processes and realized more sensitive quantitative detection of target biomolecules. We carried a multiplexed detection of several types of anti-IgG to verify the quantitative analysis performance of the system. A limit of detection of 1.48×10-10 M was achieved, demonstrating the detection sensitivity of the optical demodulation system.

Functional Based Adaptive and Fuzzy Sliding Controller for Non-Autonomous Active Suspension System

Science.gov (United States)

Huang, Shiuh-Jer; Chen, Hung-Yi

In this paper, an adaptive sliding controller is developed for controlling a vehicle active suspension system. The functional approximation technique is employed to substitute the unknown non-autonomous functions of the suspension system and release the model-based requirement of sliding mode control algorithm. In order to improve the control performance and reduce the implementation problem, a fuzzy strategy with online learning ability is added to compensate the functional approximation error. The update laws of the functional approximation coefficients and the fuzzy tuning parameters are derived from the Lyapunov theorem to guarantee the system stability. The proposed controller is implemented on a quarter-car hydraulic actuating active suspension system test-rig. The experimental results show that the proposed controller suppresses the oscillation amplitude of the suspension system effectively.

Electromagnetic fields in biological systems

National Research Council Canada - National Science Library

Lin, James C

2012-01-01

"Focusing on exposure, induced fields, and absorbed energy, this volume covers the interaction of electromagnetic fields and waves with biological systems, spanning static fields to terahertz waves...

Electromagnetic scattering theory

Science.gov (United States)

Bird, J. F.; Farrell, R. A.

1986-01-01

Electromagnetic scattering theory is discussed with emphasis on the general stochastic variational principle (SVP) and its applications. The stochastic version of the Schwinger-type variational principle is presented, and explicit expressions for its integrals are considered. Results are summarized for scalar wave scattering from a classic rough-surface model and for vector wave scattering from a random dielectric-body model. Also considered are the selection of trial functions and the variational improvement of the Kirchhoff short-wave approximation appropriate to large size-parameters. Other applications of vector field theory discussed include a general vision theory and the analysis of hydromagnetism induced by ocean motion across the geomagnetic field. Levitational force-torque in the magnetic suspension of the disturbance compensation system (DISCOS), now deployed in NOVA satellites, is also analyzed using the developed theory.

A comparison of optimal semi-active suspension systems regarding vehicle ride comfort

Science.gov (United States)

Koulocheris, Dimitrios; Papaioannou, Georgios; Chrysos, Emmanouil

2017-10-01

The aim of this work is to present a comparison of the main semi active suspension systems used in a passenger car, after having optimized the suspension systems of the vehicle model in respect with ride comfort and road holding. Thus, a half car model, equipped with controllable dampers, along with a seat and a driver was implemented. Semi-active suspensions have received a lot of attention since they seem to provide the best compromise between cost (energy consumption, actuators/sensors hardware) and performance in comparison with active and passive suspensions. In this work, the semi active suspension systems studied are comfort oriented and consist of (a) the two version of Skyhook control (two states skyhook and skyhook linear approximation damper), (b) the acceleration driven damper (ADD), (c) the power driven damper (PDD), (d) the combination of Skyhook and ADD (Mixed Skyhook-ADD) and (e) the combination of the two with the use of a sensor. The half car model equipped with the above suspension systems was excited by a road bump, and was optimized using genetic algorithms (GA) in respect with ride comfort and road holding. This study aims to highlight how the optimization of the vehicle model could lead to the best compromise between ride comfort and road holding, overcoming their well-known trade-off. The optimum results were compared with important performance metrics regarding the vehicle’s dynamic behaviour in general.

Decoupling Control Design for the Module Suspension Control System in Maglev Train

Directory of Open Access Journals (Sweden)

Guang He

2015-01-01

Full Text Available An engineering oriented decoupling control method for the module suspension system is proposed to solve the coupling issues of the two levitation units of the module in magnetic levitation (maglev train. According to the format of the system transfer matrix, a modified adjoint transfer matrix based decoupler is designed. Then, a compensated controller is obtained in the light of a desired close loop system performance. Optimization between the performance index and robustness index is also carried out to determine the controller parameters. However, due to the high orders and complexity of the obtained resultant controller, model reduction method is adopted to get a simplified controller with PID structure. Considering the modeling errors of the module suspension system as the uncertainties, experiments have been performed to obtain the weighting function of the system uncertainties. By using this, the robust stability of the decoupled module suspension control system is checked. Finally, the effectiveness of the proposed decoupling design method is validated by simulations and physical experiments. The results illustrate that the presented decoupling design can result in a satisfactory decoupling and better dynamic performance, especially promoting the reliability of the suspension control system in practical engineering application.

Use of MBS (ADAMS / CAR software in simulations of vehicle suspension systems

Directory of Open Access Journals (Sweden)

Łukasz KONIECZNY

2014-03-01

Full Text Available The results of the examination of a vehicle suspension system in the plate position are presented in the paper. The model vehicle is a Fiat Seicento with front independent suspension, McPherson type, with the steering system and with the semi-trailing arm in the rear suspension. Identification of the model was made by comparing the simulation results with the results from the test stand. A multibody model of the vehicle will be used in studies of the impact of shock absorber technical conditions on the dynamics of automotive vehicles.

A novel magnetic suspension cum linear actuator system for satellite cryo coolers

International Nuclear Information System (INIS)

Sivadasan, K.K.

1994-01-01

Stirling cycle cryogenic coolers have been widely used for device cooling in satellites. Various types of magnetic bearings and linear actuators find application in such systems. The most widely used configurations have two-axis-radially-active suspension stations placed at either ends of a reciprocating shaft in the compression and expansion sections. Separate or integral liner motors are provided in each section for axial shaft movement. It may be noted that such configurations are rather complicated and less reliable because of the presence of numerous electro-mechanical components, sensors and electronic servo channels. In this paper, a simple and reliable scheme is suggested which axially stabilizes and linearly perturbs the piston so that the need for a separate motor for axial actuation can be totally dispensed with. The piston is radially supported by passive repulsive bearings. In the axial direction, a servo actuator ''balances'' the piston and also actuates it bi-directionally. Implemented of this ''bearing cum motor theme,'' reduces the number of electromechanical and electronic components required to operate the system and hence minimizes the chances of system failure. Apart from this, the system's power consumption is reduced and efficiency is improved as electrical heating losses caused by quiescent-operating currents are removed and electromagnetic losses on the moving parts are minimized. The necessary system parameters have been derived using finite element analysis techniques. Finally, the proposed design is validated by computer-aided system simulation

Inductive-pulsed power supplying system for a betatron electromagnet

International Nuclear Information System (INIS)

Otrubyannikov, Yu.A.; Safronov, A.S.

1984-01-01

Circuit of producing quasitriangular current pulses designed for the pulsed power supply system of betatron electromagnet is described. Introduction of additional winding into electromagnet provides circuit galvanic isolation, artificial commutation of basic circuit thyristors and inductive power input to the winding during thyristor commutation. The considered system is used for excitation of betatron electromagnet up to 18 MeV. Magnetic field energy equals 1100 Y. The maximal voltage in energy storage capacitor - 4.8 kV. Current amplitude in basic winding - 335 A. The number of loops in basic winding equals 80, in additional one - 32. Current pulse duration in electromagnet-3.8 ms. The system provides operation with controlled current pulse frequency from 0 up to 150 Hz. The maximal consumption power - 18 kW

Time response analysis in suspension system design of a high-speed car

Science.gov (United States)

Pagwiwoko, Cosmas Pandit

2010-03-01

A land speed record vehicle is designed to run on a flat surface like salt lake where the wheels are normally made from solid metal with a special suspension system. The suspension is designed to provide a stable platform to keep the wheel treads on tract, to insulate the car and the driver from the surface irregularities and to take part of good handling properties. The surface condition of the lake beds is basically flat without undulations but with inconsistent surface textures and ridges. Spring with nonlinear rate is used with the reason that the resistance builds up roughly proportional to the aerodynamic download for keeping the height more nearly constant. The objective of the work is to produce an efficient method for assisting the design of suspension system. At the initial step, the stiffness and the damping constants are determined based on RMS optimization by following the optimization strategy i.e. to minimize the absolute acceleration respect to the relative displacement of the suspension. Power bond graph technique is then used to model the nonlinearity of the components i.e. spring and dashpot of the suspension system. This technique also enables to incorporate the interactions of dynamic response of the vehicle's body with aerodynamic flow as a result of the base excitation of the ground to the wheels. The simulation is conducted on the platform of Simulink-MATLAB and the interactions amongst the components within the system are observed in time domain to evaluate the effectiveness of the suspension.

Ride performance of a high speed rail vehicle using controlled semi active suspension system

Science.gov (United States)

Sharma, Sunil Kumar; Kumar, Anil

2017-05-01

The rail-wheel interaction in a rail vehicle running at high speed results in large amplitude vibration of carbody that deteriorates the ride comfort of travellers. The role of suspension system is crucial to provide an acceptable level of ride performance. In this context, an existing rail vehicle is modelled in vertical, pitch and roll motions of carbody and bogies. Additionally, nonlinear stiffness and damping parameters of passive suspension system are defined based on experimental data. In the secondary vertical suspension system, a magneto-rheological (MR) damper is included to improve the ride quality and comfort. The parameters of MR damper depend on the current, amplitude and frequency of excitations. At different running speeds, three semi-active suspension strategies with MR damper are analysed for periodic track irregularity and the resulting performance indices are juxtaposed with the nonlinear passive suspension system. The disturbance rejection and force tracking damper controller algorithms are applied to control the desired force of MR damper. This study reveals that the vertical vibrations of a vehicle can be reduced significantly by using the proposed semi-active suspension strategies. Moreover, it naturally results in improved ride quality and passenger’s comfort in comparison to the existing passive system.

An electromagnetic system for biosensors

NARCIS (Netherlands)

2008-01-01

The invention relates to an electromagnetic system for biosensors, in which the system can switch quickly between high magnetic gradients, without the need of movement of mech. elements. This is realized by two independent emu which are sepd. in the region of the pole shoes over a gap, in which a

Design analysis of formula student race car suspension system

Science.gov (United States)

Wirawan, Julian Wisnu; Ubaidillah, Aditra, Rama; Alnursyah, Rafli; Rahman, Rizki Abdul; Cahyono, Sukmaji Indro

2018-02-01

Design analysis of suspension especially for racecar suspension is very crucial to achieve maximum performance and handling. Suspension design may vary depending on the road terrain and the vehicle purpose itself, such as high speed or off-road vehicle. This paper focused on the suspension which used for racecar vehicle. The suspension type used was unequal double wishbone. This model is used because of its stability for high-speed usage compared to another kind of suspension. The suspension parameter was calculated to achieve desired performance. The result is the motion ratio of the designed suspension geometry. The obtained value of motion ratio was 1:2 for front suspension and 1:1 for the rear suspension. These calculation result the front suspension is still too soft, which the optimal motion ratio should be kept around 1:1 for better handling. This problem caused by the lack of space for suspension linkage.

System for detecting and processing abnormality in electromagnetic shielding

International Nuclear Information System (INIS)

Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

1991-01-01

The present invention relates to a system for detecting and processing an abnormality in electromagnetic shielding of an intelligent building which is constructed using an electromagnetic shielding material for the skeleton and openings such as windows and doorways so that the whole of the building is formed into an electromagnetic shielding structure. (author). 4 figs

Inertia Wheel on Low-Noise Active Magnetic Suspension

Science.gov (United States)

Carabelli, S.; Genta, G.; Silvagni, M.; Tonoli, A.

2002-01-01

precision in force measuring or vibration isolation which are required. Note that the stiffness of a magnetic suspension usually increases when it must compensate for a large static force and the increase of stiffness changes drastically the vibration isolation characteristics. It is also possible to support the rotor using a separate controlled electromagnet, but the latter will introduce disturbances which make impossible to evaluate the performances of the magnetic levitation system. Moreover, the sensitivity of the device to the operating conditions makes testing in conditions so different from the actual ones of very little significance. This is particularly true when accurate force measuring or vibration isolation is required or when low power consumption is one of the design specifications. Finally, if an external electromagnetic device is used for compensating for weight, its presence changes the stiffness of the system, to the point of altering drastically its stability characteristics. Parabolic flight is not a solution for this problem: the duration of low gravity conditions during parabolic flights is too short to perform significant experiments on magnetic suspension systems, particularly if the natural frequency of the suspension is very low as is typical of devices aimed at the isolation from low frequency vibrations. The environment in which parabolic flight testing is performed is also too rough for accurate testing. The availability of the space station changes deeply this situation: magnetic levitation systems built for space application can be tested in conditions which are very close to the operating ones. Although the space station environment is not vibrationally so clean as it would be necessary for some application, it is nevertheless far better than any simulated environment on the ground. The present paper deals with the design and construction of an engineering model of an inertia wheel on AMB. The aim of the project is to test the performance of

Muscle Activation during Push-Ups with Different Suspension Training Systems

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Joaquin Calatayud, Sebastien Borreani, Juan C. Colado, Fernando F Martín, Michael E. Rogers

2014-09-01

Full Text Available The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29 performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC. Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p < 0.001. Individually, the suspended push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation.

The modecleaner system and suspension aspects of GEO 600

CERN Document Server

Gossler, S; Freise, A; Grote, H; Lück, H B; McNamara, P; Plissi, M V; Robertson, D I; Robertson, N A; Skeldon, K D; Strain, K A; Torrie, C I; Ward, H; Willke, B; Hough, J; Danzmann, K

2002-01-01

GEO 600 uses two 8 m triangular ring cavities as a modecleaner system for the stabilization of the laser. To isolate the cavities with respect to the seismic noise the optical components are suspended as double pendulums. The resonances of these pendulums are damped by a local-control loop via magnet-coil actuators acting on the intermediate masses. The suspension scheme and the measured key data (i.e. finesse, linewidth, visibility, throughput and in-lock durations of the cavities, as well as the isolation performance and the resulting frequency stability) of the modecleaner system will be given in this paper. Furthermore an overview of the GEO 600 interferometer suspension will be given.

Optimization of damping in the passive automotive suspension system with using two quarter-car models

Science.gov (United States)

Lozia, Z.; Zdanowicz, P.

2016-09-01

The paper presents the optimization of damping in the passive suspension system of a motor vehicle moving rectilinearly with a constant speed on a road with rough surface of random irregularities, described according to the ISO classification. Two quarter-car 2DoF models, linear and non-linear, were used; in the latter, nonlinearities of spring characteristics of the suspension system and pneumatic tyres, sliding friction in the suspension system, and wheel lift-off were taken into account. The smoothing properties of vehicle tyres were represented in both models. The calculations were carried out for three roads of different quality, with simulating four vehicle speeds. Statistical measures of vertical vehicle body vibrations and of changes in the vertical tyre/road contact force were used as the criteria of system optimization and model comparison. The design suspension displacement limit was also taken into account. The optimum suspension damping coefficient was determined and the impact of undesirable sliding friction in the suspension system on the calculation results was estimated. The results obtained make it possible to evaluate the impact of the structure and complexity of the model used on the results of the optimization.

Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

Science.gov (United States)

Yan, Shuai; Sun, Weichao

2017-09-01

Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

Kineto-dynamic design optimisation for vehicle-specific seat-suspension systems

Science.gov (United States)

Shangguan, Wen-Bin; Shui, Yijie; Rakheja, Subhash

2017-11-01

Designs and analyses of seat-suspension systems are invariably performed considering effective vertical spring rate and damping properties, while neglecting important contributions due to kinematics of the widely used cross-linkage mechanism. In this study, a kineto-dynamic model of a seat-suspension is formulated to obtain relations for effective vertical suspension stiffness and damping characteristics as functions of those of the air spring and the hydraulic damper, respectively. The proposed relations are verified through simulations of the multi-body dynamic model of the cross-linkage seat-suspension in the ADAMS platform. The validity of the kineto-dynamic model is also demonstrated through comparisons of its vibration transmission response with the experimental data. The model is used to identify optimal air spring coordinates to attain nearly constant natural frequency of the suspension, irrespective of the seated body mass and seated height. A methodology is further proposed to identify optimal damping requirements for vehicle-specific suspension designs to achieve minimal seat effective amplitude transmissibility (SEAT) and vibration dose value (VDV) considering vibration spectra of different classes of earthmoving vehicles. The shock and vibration isolation performance potentials of the optimal designs are evaluated under selected vehicle vibration superimposed with shock motions. Results show that the vehicle-specific optimal designs could provide substantial reductions in the SEAT and VDV values for the vehicle classes considered.

A hybrid power system for unmanned aerial vehicle electromagnetic launcher

Science.gov (United States)

Wang, Zhiren; Wu, Jun; Huang, Shengjun

2018-06-01

According to the UAV electromagnetic catapult with fixed timing, a hybrid energy storage system consist with battery and super capacitor is designed, in order to reduce the volume and weight of the energy storage system. The battery is regarded as the energy storage device and the super capacitor as power release device. Firstly, the battery charges the super capacitor, and then the super capacitor supplies power to electromagnetic catapult separately. The strategy is using the Buck circuit to charge the super capacitor with constant current and using the Boost circuit to make super capacitor provide a stable voltage circuit for electromagnetic catapult. The Simulink simulation results show that the designed hybrid energy storage system can meet the requirements of electromagnetic catapult. Compared with the system powered by the battery alone, the proposed scheme can reduce the number of batteries, and greatly reduce the volume and weight of the energy storage system.

Modal and Dynamic Analysis of a Vehicle with Kinetic Dynamic Suspension System

Directory of Open Access Journals (Sweden)

Bangji Zhang

2016-01-01

Full Text Available A novel kinetic dynamic suspension (KDS system is presented for the cooperative control of the roll and warp motion modes of off-road vehicles. The proposed KDS system consists of two hydraulic cylinders acting on the antiroll bars. Hence, the antiroll bars are not completely replaced by the hydraulic system, but both systems are installed. In this paper, the vibration analysis in terms of natural frequencies of different motion modes in frequency domain for an off-road vehicle equipped with different configurable suspension systems is studied by using the modal analysis method. The dynamic responses of the vehicle with different configurable suspension systems are investigated under different road excitations and maneuvers. The results of the modal and dynamic analysis prove that the KDS system can reduce the roll and articulation motions of the off-road vehicle without adding extra bounce stiffness and deteriorating the ride comfort. Furthermore, the roll stiffness is increased and the warp stiffness is decreased by the KDS system, which could significantly enhance handing performance and off-road capability.

Multivectored Superficial Muscular Aponeurotic System Suspension for Facial Paralysis.

Science.gov (United States)

Leach, Garrison; Kurnik, Nicole; Joganic, Jessica; Joganic, Edward

2017-06-01

Facial paralysis is a devastating condition that may cause severe cosmetic and functional deformities. In this study we describe our technique for superficial muscular aponeurotic system (SMAS) suspension using barbed suture and compare the vectors of suspension in relation to the underlying musculature. This study also quantifies the improvements in postoperative symmetry using traditional anthropologic landmarks. The efficacy of this procedure for improving facial paralysis was determined by comparing anthropometric indices and using Procrustes distance between 4 groupings of homologous landmarks plotted on each patient's preoperative and postoperative photos. Geometric morphometrics was used to evaluate change in facial shape and improvement in symmetry postoperatively.To analyze the vector of suspension in relation to the underlying musculature, specific anthropologic landmarks were used to calculate the vector of the musculature in 3 facial hemispheres from cadaveric controls against the vector of repair in our patients. Ten patients were included in our study. Subjectively, great improvement in functional status was achieved. Geometric morphometric analysis demonstrated a statistically significant improvement in facial symmetry. Cadaveric dissection demonstrated that the suture should be placed in the SMAS in vectors parallel to the underlying musculature to achieve these results. There were no complications in our study to date. In conclusion, multivectored SMAS suture suspension is an effective method for restoring static suspension of the face after facial paralysis. This method has the benefit of producing quick, reliable results with improved function, low cost, and low morbidity.

A semi-active control suspension system for railway vehicles with magnetorheological fluid dampers

Science.gov (United States)

Wei, Xiukun; Zhu, Ming; Jia, Limin

2016-07-01

The high-speed train has achieved great progress in the last decades. It is one of the most important modes of transportation between cities. With the rapid development of the high-speed train, its safety issue is paid much more attention than ever before. To improve the stability of the vehicle with high speed, extra dampers (i.e. anti-hunting damper) are used in the traditional bogies with passive suspension system. However, the curving performance of the vehicle is undermined due to the extra lateral force generated by the dampers. The active suspension systems proposed in the last decades attempt to solve the vehicle steering issue. However, the active suspension systems need extra actuators driven by electrical power or hydraulic power. There are some implementation and even safety issues which are not easy to be overcome. In this paper, an innovative semi-active controlled lateral suspension system for railway vehicles is proposed. Four magnetorheological fluid dampers are fixed to the primary suspension system of each bogie. They are controlled by online controllers for enhancing the running stability on the straight track line on the one hand and further improving the curving performance by controlling the damper force on the other hand. Two control strategies are proposed in the light of the pure rolling concept. The effectiveness of the proposed strategies is demonstrated by SIMPACK and Matlab co-simulation for a full railway vehicle with two conventional bogies.

Online Adaptive Optimal Control of Vehicle Active Suspension Systems Using Single-Network Approximate Dynamic Programming

Directory of Open Access Journals (Sweden)

Zhi-Jun Fu

2017-01-01

Full Text Available In view of the performance requirements (e.g., ride comfort, road holding, and suspension space limitation for vehicle suspension systems, this paper proposes an adaptive optimal control method for quarter-car active suspension system by using the approximate dynamic programming approach (ADP. Online optimal control law is obtained by using a single adaptive critic NN to approximate the solution of the Hamilton-Jacobi-Bellman (HJB equation. Stability of the closed-loop system is proved by Lyapunov theory. Compared with the classic linear quadratic regulator (LQR approach, the proposed ADP-based adaptive optimal control method demonstrates improved performance in the presence of parametric uncertainties (e.g., sprung mass and unknown road displacement. Numerical simulation results of a sedan suspension system are presented to verify the effectiveness of the proposed control strategy.

Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

Science.gov (United States)

Rote, D.M.; He, J.; Johnson, L.R.

1994-01-04

A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

Science.gov (United States)

Rote, Donald M.; He, Jianliang; Johnson, Larry R.

1994-01-01

A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

Suspension system vibration analysis with regard to variable type ability to smooth road irregularities

Science.gov (United States)

Rykov, S. P.; Rykova, O. A.; Koval, V. S.; Makhno, D. E.; Fedotov, K. V.

2018-03-01

The paper aims to analyze vibrations of the dynamic system equivalent of the suspension system with regard to tyre ability to smooth road irregularities. The research is based on static dynamics for linear systems of automated control, methods of correlation, spectral and numerical analysis. Input of new data on the smoothing effect of the pneumatic tyre reflecting changes of a contact area between the wheel and road under vibrations of the suspension makes the system non-linear which requires using numerical analysis methods. Taking into account the variable smoothing ability of the tyre when calculating suspension vibrations, one can approximate calculation and experimental results and improve the constant smoothing ability of the tyre.

Vibration control of an MR vehicle suspension system considering both hysteretic behavior and parameter variation

International Nuclear Information System (INIS)

Choi, Seung-Bok; Seong, Min-Sang; Ha, Sung-Hoon

2009-01-01

This paper presents vibration control responses of a controllable magnetorheological (MR) suspension system considering the two most important characteristics of the system; the field-dependent hysteretic behavior of the MR damper and the parameter variation of the suspension. In order to achieve this goal, a cylindrical MR damper which is applicable to a middle-sized passenger car is designed and manufactured. After verifying the damping force controllability, the field-dependent hysteretic behavior of the MR damper is identified using the Preisach hysteresis model. The full-vehicle suspension model is then derived by considering vertical, pitch and roll motions. An H ∞ controller is designed by treating the sprung mass of the vehicle as a parameter variation and integrating it with the hysteretic compensator which produces additional control input. In order to demonstrate the effectiveness and robustness of the proposed control system, the hardware-in-the-loop simulation (HILS) methodology is adopted by integrating the suspension model with the proposed MR damper. Vibration control responses of the vehicle suspension system such as vertical acceleration are evaluated under both bump and random road conditions

Design and Optimization of Intelligent Service Robot Suspension System Using Dynamic Model

International Nuclear Information System (INIS)

Choi, Seong Hoon; Park, Tae Won; Lee, Soo Ho; Jung, Sung Pil; Jun, Kab Jin; Yoon, J. W.

2010-01-01

Recently, an intelligent service robot is being developed for use in guiding and providing information to visitors about the building at public institutions. The intelligent robot has a sensor at the bottom to recognize its location. Four wheels, which are arranged in the form of a lozenge, support the robot. This robot cannot be operated on uneven ground because its driving parts are attached to its main body that contains the important internal components. Continuous impact with the ground can change the precise positions of the components and weaken the connection between each structural part. In this paper, the design of the suspension system for such a robot is described. The dynamic model of the robot is created, and the driving characteristics of the robot with the designed suspension system are simulated. Additionally, the suspension system is optimized to reduce the impact for the robot components

Discrete-time sliding mode control for MR vehicle suspension system

Energy Technology Data Exchange (ETDEWEB)

Sohn, J W; Choi, S B [Smart Structures and Systems Laboratory, Department of Mechanical Engineering, Inha University, Incheon 402-751 (Korea, Republic of); Wereley, N M [Smart Structures Laboratory, Department of Aerospace Engineering, University of Maryland, College Park, MD 20742 (United States)], E-mail: seungbok@inha.ac.kr

2009-02-01

This paper presents control performance of a full-vehicle suspension system featuring magnetorheological (MR) dampers via a discrete-time sliding mode control algorithm (DSMC). A cylindrical MR damper is designed by incorporating Bingham model of the MR fluid and the field-dependent damping characteristics of the MR damper are evaluated. A full-vehicle suspension model installed with independent four MR dampers is constructed and the governing equations which include vertical, pitch and roll motion are derived. A discrete-time control model is established with considering system uncertainties and a discrete-time sliding mode controller which has inherent robustness to model uncertainty and external disturbance is formulated. Vibration control performances under bump excitation are evaluated and presented.

Discrete-time sliding mode control for MR vehicle suspension system

International Nuclear Information System (INIS)

Sohn, J W; Choi, S B; Wereley, N M

2009-01-01

This paper presents control performance of a full-vehicle suspension system featuring magnetorheological (MR) dampers via a discrete-time sliding mode control algorithm (DSMC). A cylindrical MR damper is designed by incorporating Bingham model of the MR fluid and the field-dependent damping characteristics of the MR damper are evaluated. A full-vehicle suspension model installed with independent four MR dampers is constructed and the governing equations which include vertical, pitch and roll motion are derived. A discrete-time control model is established with considering system uncertainties and a discrete-time sliding mode controller which has inherent robustness to model uncertainty and external disturbance is formulated. Vibration control performances under bump excitation are evaluated and presented.

Administrative license suspension: Does length of suspension matter?

Science.gov (United States)

Fell, James C; Scherer, Michael

2017-08-18

Administrative license revocation (ALR) laws, which provide that the license of a driver with a blood alcohol concentration at or over the illegal limit is subject to an immediate suspension by the state department of motor vehicles, are an example of a traffic law in which the sanction rapidly follows the offense. The power of ALR laws has been attributed to how swiftly the sanction is applied, but does the length of suspension matter? Our objectives were to (a) determine the relationship of the ALR suspension length to the prevalence of drinking drivers relative to sober drivers in fatal crashes and (b) estimate the extent to which the relationship is associated to the general deterrent effect compared to the specific deterrent effect of the law. Data comparing the impact of ALR law implementation and ALR law suspension periods were analyzed using structural equation modeling techniques on the ratio of drinking drivers to nondrinking drivers in fatal crashes from the Fatality Analysis Reporting System (FARS). States with an ALR law with a short suspension period (1-30 days) had a significantly lower drinking driver ratio than states with no ALR law. States with a suspension period of 91-180 days had significantly lower ratios than states with shorter suspension periods, while the three states with suspension lengths of 181 days or longer had significantly lower ratios than states with shorter suspension periods. The implementation of any ALR law was associated with a 13.1% decrease in the drinking/nondrinking driver fatal crash ratio but only a 1.8% decrease in the intoxicated/nonintoxicated fatal crash ratio. The ALR laws and suspension lengths had a significant general deterrent effect, but no specific deterrent effect. States might want to keep (or adopt) ALR laws for their general deterrent effects and pursue alternatives for specific deterrent effects. States with short ALR suspension periods should consider lengthening them to 91 days or longer.

Adaptive Control of Electromagnetic Suspension System by HOPF Bifurcation

Directory of Open Access Journals (Sweden)

Aming Hao

2013-01-01

Full Text Available EMS-type maglev system is essentially nonlinear and unstable. It is complicated to design a stable controller for maglev system which is under large-scale disturbance and parameter variance. Theory analysis expresses that this phenomenon corresponds to a HOPF bifurcation in mathematical model. An adaptive control law which adjusts the PID control parameters is given in this paper according to HOPF bifurcation theory. Through identification of the levitated mass, the controller adjusts the feedback coefficient to make the system far from the HOPF bifurcation point and maintain the stability of the maglev system. Simulation result indicates that adjusting proportion gain parameter using this method can extend the state stability range of maglev system and avoid the self-excited vibration efficiently.

Demonstration of a switchable damping system to allow low-noise operation of high-Q low-mass suspension systems

Science.gov (United States)

Hennig, Jan-Simon; Barr, Bryan W.; Bell, Angus S.; Cunningham, William; Danilishin, Stefan L.; Dupej, Peter; Gräf, Christian; Hough, James; Huttner, Sabina H.; Jones, Russell; Leavey, Sean S.; Pascucci, Daniela; Sinclair, Martin; Sorazu, Borja; Spencer, Andrew; Steinlechner, Sebastian; Strain, Kenneth A.; Wright, Jennifer; Zhang, Teng; Hild, Stefan

2017-12-01

Low-mass suspension systems with high-Q pendulum stages are used to enable quantum radiation pressure noise limited experiments. Utilizing multiple pendulum stages with vertical blade springs and materials with high-quality factors provides attenuation of seismic and thermal noise; however, damping of these high-Q pendulum systems in multiple degrees of freedom is essential for practical implementation. Viscous damping such as eddy-current damping can be employed, but it introduces displacement noise from force noise due to thermal fluctuations in the damping system. In this paper we demonstrate a passive damping system with adjustable damping strength as a solution for this problem that can be used for low-mass suspension systems without adding additional displacement noise in science mode. We show a reduction of the damping factor by a factor of 8 on a test suspension and provide a general optimization for this system.

Study of piezoelectric materials combined with electromagnetic design for bicycle harvesting system

Directory of Open Access Journals (Sweden)

Dyi-Cheng Chen

2016-04-01

Full Text Available Energy harvesting device involves capturing energy from the environment and it is increasingly crucial in the crisis of greenhouse effect nowadays. Equipping bicycles with many types of shock absorbers can enhance the riding comfort. Additionally, an embedded energy harvesting device will gain much benefit beyond the sports. This study applied the finite element method to analyze the components of nonlinear magnetic spring. The analytical simulations were conducted to analyze the electromagnetic effect in ANSYS©/Emag software. A model equipped with nonlinear magnetic springs was constructed to absorb the impact energy. Nevertheless, the piezoelectric components were used to capture the piezoelectric effect current caused by the compressive stress. A series of simulations were conducted, such as changing the diameter of the magnet, electric coil width, and the position of the coils. Moreover, with those finite element analysis data, the Taguchi method L9(34 orthogonal arrays were applied to determine the optimal parametric dimensions of the electromagnetic and piezoelectric assemblies for maximizing the captured kinetic energy and power transformation. The results could assist the suspension manufacturers to innovate their design for energy harvesting and impact absorbing.

Electromagnetic driving units for complex microrobotic systems

Science.gov (United States)

Michel, Frank; Ehrfeld, Wolfgang; Berg, Udo; Degen, Reinhard; Schmitz, Felix

1998-10-01

Electromagnetic actuators play an important role in macroscopic robotic systems. In combination with motion transformers, like reducing gear units, angular gears or spindle-screw drives, electromagnetic motors in large product lines ensure the rotational or linear motion of robot driving units and grippers while electromagnets drive valves or part conveyors. In this paper micro actuators and miniaturized motion transformers are introduced which allow a similar development in microrobotics. An electromagnetic motor and a planetary gear box, both with a diameter of 1.9 mm, are already commercially available from the cooperation partner of IMM, the company Dr. Fritz Faulhaber GmbH in Schonaich, Germany. In addition, a motor with a diameter of 2.4 mm is in development. The motors successfully drive an angular gear and a belt drive. A linear stage with a motion range of 7 mm and an overall size as small as 5 X 3.5 X 24 mm3 has been realized involving the motor, a stationary spur gear with zero backlash and a spindle-screw drive. By the use of these commercially available elements complex microrobots can be built up cost-efficiently and rapidly. Furthermore, a batch process has been developed to produce the coils of micro actuator arrays using lithographic techniques with SU-8 resin. In applying these components, the modular construction of complex microrobotic systems becomes feasible.

Robust finite-time tracking control for nonlinear suspension systems via disturbance compensation

Science.gov (United States)

Pan, Huihui; Jing, Xingjian; Sun, Weichao

2017-05-01

This paper focuses on the finite-time tracking control with external disturbance for active suspension systems. In order to compensate unknown disturbance efficiently, a disturbance compensator with finite-time convergence property is studied. By analyzing the discontinuous phenomenon of classical disturbance compensation techniques, this study presents a simple approach to construct a continuous compensator satisfying the finite-time disturbance rejection performance. According to the finite-time separation principle, the design procedures of the nominal controller for the suspension system without disturbance and the disturbance compensator can be implemented in a completely independent manner. Therefore, the overall control law for the closed-loop system is continuous, which offers some distinct advantages over the existing discontinuous ones. From the perspective of practical implementation, the continuous controller can avoid effectively the unexpected chattering in active suspension control. Comparative experimental results are presented and discussed to illustrate the advantage and effectiveness of the proposed control strategy.

[Influence of electromagnetic field on chosen parameters of thrombocytes' oxygen metabolism--in vitro research].

Science.gov (United States)

Jankowski, Wojciech; Henrykowska, Gabriela; Smigielski, Janusz; Pacholski, Krzysztof; Dziedziczak-Buczyńska, Maria; Kałka, Krzysztof; Buczyński, Andrzej

2008-06-01

Being a natural environmental factor, an electromagnetic field exists from the beginning of the life on Earth and it has an influence on maintenance of life processes. Natural electromagnetic fields affect day and year rhythms of plants, animals and humans. As a result of an electromagnetic field's activity, there occurs a disorder of blood platelets' function, which may, in consequence, lead to acute and chronic conditions dangerous to health and life. The aim of this work was to assess the influence, which a shape of an electromagnetic field of low frequency has on generating free radicals and enzymatic activity of superoxide dismutase in human blood platelets. Suspension of human blood platelets was subjected to activity of electromagnetic field of different shapes, frequency of 50 Hz and induction of 10 mT for 15 and 30 minutes. An electromagnetic field was generated with Helmholtz coils arranged on a bracket, inside of which test tubes with the blood platelets' suspension were put. Next, they were subjected to an activity of a specific electromagnetic field. The measurement of free radicals generation indicated an increase, in comparison with the initial values, after 15 minutes as well as 30 minutes of exposition, regardless of the electromagnetic field's shape, whereas the enzymatic activity of superoxide dismutase decreased, in comparison with the initial values, after 15 minutes as well as 30 minutes of exposition, regardless of the applied electromagnetic field's shape. Basing on obtained results, it may be stated that the level of generating free radicals as well as the level of enzymatic activity of superoxide dismutase in tested blood cells indicates significant dependence on an electromagnetic field's shape. The greatest changes have been observed during the activity of a rectangular and triangular pulse.

Sky-Hook Control and Kalman Filtering in Nonlinear Model of Tracked Vehicle Suspension System

Directory of Open Access Journals (Sweden)

Jurkiewicz Andrzej

2017-09-01

Full Text Available The essence of the undertaken topic is application of the continuous sky-hook control strategy and the Extended Kalman Filter as the state observer in the 2S1 tracked vehicle suspension system. The half-car model of this suspension system consists of seven logarithmic spiral springs and two magnetorheological dampers which has been described by the Bingham model. The applied continuous sky-hook control strategy considers nonlinear stiffness characteristic of the logarithmic spiral springs. The control is determined on estimates generated by the Extended Kalman Filter. Improve of ride comfort is verified by comparing simulation results, under the same driving conditions, of controlled and passive vehicle suspension systems.

Digital control of wind tunnel magnetic suspension and balance systems

Science.gov (United States)

Britcher, Colin P.; Goodyer, Michael J.; Eskins, Jonathan; Parker, David; Halford, Robert J.

1987-01-01

Digital controllers are being developed for wind tunnel magnetic suspension and balance systems, which in turn permit wind tunnel testing of aircraft models free from support interference. Hardware and software features of two existing digital control systems are reviewed. Some aspects of model position sensing and system calibration are also discussed.

Design and analysis of an electromagnetic turnout for the superconducting Maglev system

International Nuclear Information System (INIS)

Li, Y.J.; Dai, Q.; Zhang, Y.; Wang, H.; Chen, Z.; Sun, R.X.; Zheng, J.; Deng, C.Y.; Deng, Z.G.

2016-01-01

Highlights: • The switching principle of electromagnetic turnout for a Halbach-type magnetic rail was presented. • Shape design and optimization of the electromagnet for electromagnetic turnout were conducted. • Magnetic field distribution over the working area of electromagnetic turnout was analyzed. • Feasibility of the electromagnetic turnout was proved. - Abstract: Turnout is a crucial track junction device of the ground rail transportation system. For high temperature superconducting (HTS) Maglev system, the permanent magnet guideway (PMG) makes the strong magnetic force existing between rail segments, which may cause moving difficulties and increase the operation cost when switching a PMG. In this paper, a non-mechanical ‘Y’ shaped Halbach-type electromagnetic turnout was proposed. By replacing the PMs with electromagnets, the turnout can guide the maglev vehicle running into another PMG by simply controlling the current direction of electromagnets. The material and structure parameters of the electromagnets were optimized by simulation. The results show that the optimized electromagnet can keep the magnetic field above it as strong as the PMs’, meanwhile feasible for design and manufacture. This work provides valuable references for the future design in non-mechanical PMG turnout.

Design and analysis of an electromagnetic turnout for the superconducting Maglev system

Energy Technology Data Exchange (ETDEWEB)

Li, Y.J. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); School of Information Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Dai, Q. [School of Information Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Zhang, Y. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Wang, H.; Chen, Z. [School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Sun, R.X.; Zheng, J. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); Deng, C.Y. [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China); School of Information Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Deng, Z.G., E-mail: deng@swjtu.cn [Applied Superconductivity Laboratory, State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031 (China)

2016-09-15

Highlights: • The switching principle of electromagnetic turnout for a Halbach-type magnetic rail was presented. • Shape design and optimization of the electromagnet for electromagnetic turnout were conducted. • Magnetic field distribution over the working area of electromagnetic turnout was analyzed. • Feasibility of the electromagnetic turnout was proved. - Abstract: Turnout is a crucial track junction device of the ground rail transportation system. For high temperature superconducting (HTS) Maglev system, the permanent magnet guideway (PMG) makes the strong magnetic force existing between rail segments, which may cause moving difficulties and increase the operation cost when switching a PMG. In this paper, a non-mechanical ‘Y’ shaped Halbach-type electromagnetic turnout was proposed. By replacing the PMs with electromagnets, the turnout can guide the maglev vehicle running into another PMG by simply controlling the current direction of electromagnets. The material and structure parameters of the electromagnets were optimized by simulation. The results show that the optimized electromagnet can keep the magnetic field above it as strong as the PMs’, meanwhile feasible for design and manufacture. This work provides valuable references for the future design in non-mechanical PMG turnout.

22 CFR 208.110 - What is the purpose of the nonprocurement debarment and suspension system?

Science.gov (United States)

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false What is the purpose of the nonprocurement debarment and suspension system? 208.110 Section 208.110 Foreign Relations AGENCY FOR INTERNATIONAL... the nonprocurement debarment and suspension system? (a) To protect the public interest, the Federal...

Performance Testing of Suspension Plasma Sprayed Thermal Barrier Coatings Produced with Varied Suspension Parameters

Directory of Open Access Journals (Sweden)

Nicholas Curry

2015-07-01

Full Text Available Suspension plasma spraying has become an emerging technology for the production of thermal barrier coatings for the gas turbine industry. Presently, though commercial systems for coating production are available, coatings remain in the development stage. Suitable suspension parameters for coating production remain an outstanding question and the influence of suspension properties on the final coatings is not well known. For this study, a number of suspensions were produced with varied solid loadings, powder size distributions and solvents. Suspensions were sprayed onto superalloy substrates coated with high velocity air fuel (HVAF -sprayed bond coats. Plasma spray parameters were selected to generate columnar structures based on previous experiments and were maintained at constant to discover the influence of the suspension behavior on coating microstructures. Testing of the produced thermal barrier coating (TBC systems has included thermal cyclic fatigue testing and thermal conductivity analysis. Pore size distribution has been characterized by mercury infiltration porosimetry. Results show a strong influence of suspension viscosity and surface tension on the microstructure of the produced coatings.

Compressible Fluid Suspension Performance Testing

National Research Council Canada - National Science Library

Hoogterp, Francis

2003-01-01

... compressible fluid suspension system that was designed and installed on the vehicle by DTI. The purpose of the tests was to evaluate the possible performance benefits of the compressible fluid suspension system...

Study on irradiation effects of nucleus electromagnetic pulse on single chip computer system

International Nuclear Information System (INIS)

Hou Minsheng; Liu Shanghe; Wang Shuping

2001-01-01

Intense electromagnetic pulse, namely nucleus electromagnetic pulse (NEMP), lightning electromagnetic pulse (LEMP) and high power microwave (HPM), can disturb and destroy the single chip computer system. To study this issue, the authors made irradiation experiments by NEMPs generated by gigahertz transversal electromagnetic (GTEM) Cell. The experiments show that shutdown, restarting, communication errors of the single chip microcomputer system would occur when it was irradiated by the NEMPs. Based on the experiments, the cause on the effects on the single chip microcomputer system is discussed

Process for washing electromagnetic filters

International Nuclear Information System (INIS)

Guittet, Maurice; Treille, Pierre.

1980-01-01

This process concerns the washing of an electro-magnetic filter used, inter alia, for filtering the drain-off waters of nuclear power station steam generators, by means of a washing water used in closed circuit and freed, after each cleaning, of the solids in suspension it contains, by settlement of these solids. This invention enables the volume of water to be evaporated to be divided by 50, thereby providing a solid assurance of better safety, apart from a very significant saving [fr

An analysis of the electromagnetic field in multi-polar linear induction system

International Nuclear Information System (INIS)

Chervenkova, Todorka; Chervenkov, Atanas

2002-01-01

In this paper a new method for determination of the electromagnetic field vectors in a multi-polar linear induction system (LIS) is described. The analysis of the electromagnetic field has been done by four dimensional electromagnetic potentials in conjunction with theory of the magnetic loops . The electromagnetic field vectors are determined in the Minkovski's space as elements of the Maxwell's tensor. The results obtained are compared with those got from the analysis made by the finite elements method (FEM).With the method represented in this paper one can determine the electromagnetic field vectors in the multi-polar linear induction system using four-dimensional potential. A priority of this method is the obtaining of analytical results for the electromagnetic field vectors. These results are also valid for linear media. The dependencies are valid also at high speeds of movement. The results of the investigated linear induction system are comparable to those got by the finite elements method. The investigations may be continued in the determination of other characteristics such as drag force, levitation force, etc. The method proposed in this paper for an analysis of linear induction system can be used for optimization calculations. (Author)

Optimization of Front Axle Suspension System of Articulated Dump Truck

DEFF Research Database (Denmark)

Langer, Thomas Heegaard; Christensen, Brian B.; Mouritsen, Ole Ø.

2010-01-01

that has been subjected to comfort improvement is a two axle articulated dump truck. The comfort has been in terms of whole body vibration exposure and the overall improvement has been made possible by adding front axle suspension. However, a hydraulic stabilizing system between the tractor and trailer...... to evaluate the whole body vibrations. By use of a multibody simulation model of the dump truck the whole body vibration exposure has been computed using the predefined work cycle as model input. The design parameters comprise the components of the hydraulic subsystem of the suspension, i.e., the size...

Multiobjective Robust Design of the Double Wishbone Suspension System Based on Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Xianfu Cheng

2014-01-01

Full Text Available The performance of the suspension system is one of the most important factors in the vehicle design. For the double wishbone suspension system, the conventional deterministic optimization does not consider any deviations of design parameters, so design sensitivity analysis and robust optimization design are proposed. In this study, the design parameters of the robust optimization are the positions of the key points, and the random factors are the uncertainties in manufacturing. A simplified model of the double wishbone suspension is established by software ADAMS. The sensitivity analysis is utilized to determine main design variables. Then, the simulation experiment is arranged and the Latin hypercube design is adopted to find the initial points. The Kriging model is employed for fitting the mean and variance of the quality characteristics according to the simulation results. Further, a particle swarm optimization method based on simple PSO is applied and the tradeoff between the mean and deviation of performance is made to solve the robust optimization problem of the double wishbone suspension system.

Multiobjective Robust Design of the Double Wishbone Suspension System Based on Particle Swarm Optimization

Science.gov (United States)

Lin, Yuqun

2014-01-01

The performance of the suspension system is one of the most important factors in the vehicle design. For the double wishbone suspension system, the conventional deterministic optimization does not consider any deviations of design parameters, so design sensitivity analysis and robust optimization design are proposed. In this study, the design parameters of the robust optimization are the positions of the key points, and the random factors are the uncertainties in manufacturing. A simplified model of the double wishbone suspension is established by software ADAMS. The sensitivity analysis is utilized to determine main design variables. Then, the simulation experiment is arranged and the Latin hypercube design is adopted to find the initial points. The Kriging model is employed for fitting the mean and variance of the quality characteristics according to the simulation results. Further, a particle swarm optimization method based on simple PSO is applied and the tradeoff between the mean and deviation of performance is made to solve the robust optimization problem of the double wishbone suspension system. PMID:24683334

Multiobjective robust design of the double wishbone suspension system based on particle swarm optimization.

Science.gov (United States)

Cheng, Xianfu; Lin, Yuqun

2014-01-01

The performance of the suspension system is one of the most important factors in the vehicle design. For the double wishbone suspension system, the conventional deterministic optimization does not consider any deviations of design parameters, so design sensitivity analysis and robust optimization design are proposed. In this study, the design parameters of the robust optimization are the positions of the key points, and the random factors are the uncertainties in manufacturing. A simplified model of the double wishbone suspension is established by software ADAMS. The sensitivity analysis is utilized to determine main design variables. Then, the simulation experiment is arranged and the Latin hypercube design is adopted to find the initial points. The Kriging model is employed for fitting the mean and variance of the quality characteristics according to the simulation results. Further, a particle swarm optimization method based on simple PSO is applied and the tradeoff between the mean and deviation of performance is made to solve the robust optimization problem of the double wishbone suspension system.

EDDYTRAN program system for eddy current, electromagnetic force and structural analysis

International Nuclear Information System (INIS)

Kameari, A.; Nikura, S.

1983-01-01

A computer program system (EDDYTRAN), which is applicable to torus structures of magnetic fusion devices, has been developed to calculate the eddy current, electromagnetic force and structural analysis. The program system is designed to perform the following functions sequentially: 1) generation of model mesh and other data such as electromagnetic and mechanical properties of finite elements and boundary conditions, 2) calculations of eddy currents and electromagnetic forces, 3) transformation of the resultant force to load data fit to the structural analysis program, 4) structural analysis and 5) post-processing of the results. The EDDYTRAN utilizes the EDDYCUFF (EDDY CUrrent, magnetic Field and electromagnetic Force) program and the NASTRAN (NASA STRuctural ANalysis) program. Here, the EDDYCUFF program which has been developed by the authors is a generalized computer program to calculate transient eddy currents, resultant magnetic fields and electromagnetic forces in the conductive components. This paper describes the outline of the EDDYTRAN program system and preliminary results obtained through the application to the Tokamak reactor design which was performed for the Japan Atomic Energy Research Institute

Muscle Activation during Push-Ups with Different Suspension Training Systems.

Science.gov (United States)

Calatayud, Joaquin; Borreani, Sebastien; Colado, Juan C; Martín, Fernando F; Rogers, Michael E; Behm, David G; Andersen, Lars L

2014-09-01

The purpose of this study was to analyze upper extremity and core muscle activation when performing push-ups with different suspension devices. Young fit male university students (n = 29) performed 3 push-ups each with 4 different suspension systems. Push-up speed was controlled using a metronome and testing order was randomized. Average amplitude of the electromyographic root mean square of Triceps Brachii, Upper Trapezius, Anterior Deltoid, Clavicular Pectoralis, Rectus Abdominis, Rectus Femoris, and Lumbar Erector Spinae was recorded. Electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC). Electromyographic data were analyzed with repeated-measures analysis of variance with a Bonferroni post hoc. Based upon global arithmetic mean of all muscles analyzed, the suspended push-up with a pulley system provided the greatest activity (37.76% of MVIC; p push-up with a pulley system also provided the greatest triceps brachii, upper trapezius, rectus femoris and erector lumbar spinae muscle activation. In contrast, more stable conditions seem more appropriate for pectoralis major and anterior deltoid muscles. Independent of the type of design, all suspension systems were especially effective training tools for reaching high levels of rectus abdominis activation. Key PointsCompared with standard push-ups on the floor, suspended push-ups increase core muscle activation.A one-anchor system with a pulley is the best option to increase TRICEP, TRAPS, LUMB and FEM muscle activity.More stable conditions such as the standard push-up or a parallel band system provide greater increases in DELT and PEC muscle activation.A suspended push-up is an effective method to achieve high muscle activity levels in the ABS.

DC electrostatic gyro suspension system for the Gravity Probe B experiment

Science.gov (United States)

Wu, Chang-Huei

1994-12-01

The Gravity Probe B experiment is a satellite-based experiment primarily designed to test two aspects of Einstein's General Theory of Relativity by observing the spin axis drift of near-perfect gyroscopes in a 650-km circular polar orbit. The goal of this experiment is to measure the drift angles to an accuracy of 0.3 milli-arcsec after one year in orbit. As a result, electrostatically suspended free-spinning gyroscopes operating at a very low temperature became the final choice for their ultra-low Newtonian torque-induced drift rate. The Conventional AC current-driven suspension system faces two fundamental difficulties for ground gyro testing. Field emission causes rotor charging and arcing with an imperfect electrode or rotor surfaces because the electric field intensity needed to support a solid rotor in the 1-g field is more than 107 V/m. The system not only becomes unstable at a high rotor charge, which can be more than 500 volts, but may also lose control in case of arcing. Both the high voltage AC suspension signal and the high frequency (1 MHz) signal for rotor position sensing interfere with the superconducting SQUID magnetometer for spin axis readout through inductive coupling. These problems were resolved by using DC voltage to generate a suspension force and a low frequency position sensor. In addition to the Input/Output linearization algorithm developed to remove the system nonlinearity for global stability and dynamic performance, we also minimized the electric field intensity to reduce rotor charging. Experimental results verified the desired global stability and satisfactory dynamic performance. The problem of rotor charging is virtually eliminated. More importantly, the DC system is compatible with the SQUID readout system in the Science Mission configuration. Consequently, experiments in low magnetic field at a sub-micro-gauss level for SQUID design verification and trapped flux distribution study were finally realizable in ground environment

Performance Tests on the Electromagnet of Secondary CRA Gripper System of the PGSFR

International Nuclear Information System (INIS)

Lee, Jae Han; Kim, Sung Kyun

2016-01-01

The system automatically releases the control rod assembly (CRA) around the set temperature in an emergency condition of the reactor, and then drops the CRA by gravity without any external control signals and any actuating power. This paper describes the design of a passive shutdown system consisted of a thermal expansion device and an electromagnet. The electromagnet design concept for gripping and releasing the secondary control rod assembly is also suggested, and the several functional tests of the electromagnet are performed in the high temperature environment condition, and the test results are presented. The application feasibility of the electromagnet of a passive shutdown system was verified based on several test results in point of view of the electromagnetic force and the response time. In future, the thermal expansion device system integrated with this electromagnet will be verified. The electromagnet trigger-off time was tested for the several cases in Table 4 using the same method. The average response time is 0.184 seconds in the case of using SS410 material as an armature, while the 2.25Cr-1Mo material as an armature has a response time of 0.16 seconds as shown in Figure 6. The final acceptability of the electromagnetic response time data obtained by these tests will be evaluated with CRA drop test results because the control rod drop time should be within 1 - 2 seconds including the electromagnetic response time

Preview based control of suspension systems for commercial vehicles

NARCIS (Netherlands)

Muijderman, J.H.E.A.; Kok, J.J.; Huisman, R.G.M.; Veldpaus, F.E.; van Heck, J.G.A.M.

1999-01-01

An active suspension with preview is developed for the rear axle of a commercial vehicle. The obtained improvements are promising and justify further investigation of the more feasible semi-active suspensions with preview. The inherent non-linearity of semi-active suspensions with switching shock

Modeling of MEMS piezoelectric energy harvesters using electromagnetic and power system theories

KAUST Repository

Ahmad, Mahmoud Al; Alshareef, Husam N.; Elshurafa, Amro M.; Salama, Khaled N.

2012-01-01

-to-electrical analogy, electromagnetic theory, and power system theory is developed. The mechanical-to-electrical analogy and power system theory allow the derivation of an equivalent input impedance expression for the network, whereas electromagnetic transmission line

Engineering Electromagnetics

International Nuclear Information System (INIS)

Kim, Se Yun

2009-01-01

This book deals with engineering electromagnetics. It contains seven chapters, which treats understanding of engineering electromagnetics such as magnet and electron spin, current and a magnetic field and an electromagnetic wave, Essential tool for engineering electromagnetics on rector and scalar, rectangular coordinate system and curl vector, electrostatic field with coulomb rule and method of electric images, Biot-Savart law, Ampere law and magnetic force, Maxwell equation and an electromagnetic wave and reflection and penetration of electromagnetic plane wave.

Entropy and Entanglement of the Electromagnetically Induced Transparency System

Institute of Scientific and Technical Information of China (English)

LIU Xiao-Juan; FANG Mao-Fa; ZHOU Qing-Ping

2004-01-01

@@ We study the entropy and the entanglement of an electromagnetically induced transparency system. The quantum entanglement between the atom and the two quantized laser fields is discussed by using quantum reduced entropy and that between the two quantized laser fields by using quantum relative entropy. We also examine whether influences of EIT on entropy and quantum entanglement of the system considered occur or not. Our results show that the minimum value of the atomic reduced entropy may be regarded as an entropy criterion on the electromagnetically induced transparency occurring.

Nonlinear Robust Observer-Based Fault Detection for Networked Suspension Control System of Maglev Train

Directory of Open Access Journals (Sweden)

Yun Li

2013-01-01

Full Text Available A fault detection approach based on nonlinear robust observer is designed for the networked suspension control system of Maglev train with random induced time delay. First, considering random bounded time-delay and external disturbance, the nonlinear model of the networked suspension control system is established. Then, a nonlinear robust observer is designed using the input of the suspension gap. And the estimate error is proved to be bounded with arbitrary precision by adopting an appropriate parameter. When sensor faults happen, the residual between the real states and the observer outputs indicates which kind of sensor failures occurs. Finally, simulation results using the actual parameters of CMS-04 maglev train indicate that the proposed method is effective for maglev train.

Stability of miniature electromagnetic tracking systems

International Nuclear Information System (INIS)

Schicho, Kurt; Figl, Michael; Donat, Markus; Birkfellner, Wolfgang; Seemann, Rudolf; Wagner, Arne; Bergmann, Helmar; Ewers, Rolf

2005-01-01

This study aims at a comparative evaluation of two recently introduced electromagnetic tracking systems under reproducible simulated operating-room (OR) conditions: the recently launched Medtronic StealthStation TM Treon-EM TM and the NDI Aurora TM . We investigate if and to what extent these systems provide improved performance and stability in the presence of surgical instruments as possible sources of distortions compared with earlier reports on electromagnetic tracking technology. To investigate possible distortions under pseudo-realistic OR conditions, a large Langenbeck hook, a dental drill with its handle and an ultrasonic (US) scanhead are fixed on a special measurement rack at variable distances from the navigation sensor. The position measurements made by the Treon-EM TM were least affected by the presence of the instruments. The lengths of the mean deviation vectors were 0.21 mm for the Langenbeck hook, 0.23 mm for the drill with handle and 0.56 mm for the US scanhead. The Aurora TM was influenced by the three sources of distortion to a higher degree. A mean deviation vector of 1.44 mm length was observed in the vicinity of the Langenbeck hook, 0.53 mm length with the drill and 2.37 mm due to the US scanhead. The maximum of the root mean squared error (RMSE) for all coordinates in the presence of the Langenbeck hook was 0.3 mm for the Treon TM and 2.1 mm for the Aurora TM ; the drill caused a maximum RMSE of 0.2 mm with the Treon TM and 1.2 mm with the Aurora TM . In the presence of the US scanhead, the maximum RMSE was 1.4 mm for the Treon TM and 5.1 mm for the Aurora TM . The new generation of electromagnetic tracking systems has significantly improved compared to common systems that were available in the middle of the 1990s and has reached a high level of technical development. We conclude that, in general, both systems are suitable for routine clinical application

Design and test of a novel magnetic lead screw for active suspension system in a vehicle

DEFF Research Database (Denmark)

Berg, Nick Ilsø; Holm, Rasmus Koldborg; Rasmussen, Peter Omand

2014-01-01

. Furthermore the Magnetic Lead Screw is introduced and its benefits when used with an active suspension system are discussed. Based on a model of a quarter car, the design specifications for the MLS active suspension system are found, which leads to a design study. The design study investigates the relation...

A comparison of helicopter-borne electromagnetic systems for hydrogeologic studies

Science.gov (United States)

Bedrosian, Paul A.; Schamper, Cyril; Auken, Esben

2016-01-01

The increased application of airborne electromagnetic surveys to hydrogeological studies is driving a demand for data that can consistently be inverted for accurate subsurface resistivity structure from the near surface to depths of several hundred metres. We present an evaluation of three commercial airborne electromagnetic systems over two test blocks in western Nebraska, USA. The selected test blocks are representative of shallow and deep alluvial aquifer systems with low groundwater salinity and an electrically conductive base of aquifer. The aquifer units show significant lithologic heterogeneity and include both modern and ancient river systems. We compared the various data sets to one another and inverted resistivity models to borehole lithology and to ground geophysical models. We find distinct differences among the airborne electromagnetic systems as regards the spatial resolution of models, the depth of investigation, and the ability to recover near-surface resistivity variations. We further identify systematic biases in some data sets, which we attribute to incomplete or inexact calibration or compensation procedures.

An integrated model for interaction of electromagnetic fields with biological systems

International Nuclear Information System (INIS)

Apollonio, F.; Liberti, M.; Cavagnaro, M.; D'Inzeo, G.; Tarricone, L.

1999-01-01

In this work is described a methodology for evaluation of interaction of high frequency electromagnetic field. Biological systems via connection of many macroscopic models. In particular the analysis of neuronal membrane exposed to electromagnetic fields [it

Design and analysis of an electromagnetic turnout for the superconducting Maglev system

Science.gov (United States)

Li, Y. J.; Dai, Q.; Zhang, Y.; Wang, H.; Chen, Z.; Sun, R. X.; Zheng, J.; Deng, C. Y.; Deng, Z. G.

2016-09-01

Turnout is a crucial track junction device of the ground rail transportation system. For high temperature superconducting (HTS) Maglev system, the permanent magnet guideway (PMG) makes the strong magnetic force existing between rail segments, which may cause moving difficulties and increase the operation cost when switching a PMG. In this paper, a non-mechanical 'Y' shaped Halbach-type electromagnetic turnout was proposed. By replacing the PMs with electromagnets, the turnout can guide the maglev vehicle running into another PMG by simply controlling the current direction of electromagnets. The material and structure parameters of the electromagnets were optimized by simulation. The results show that the optimized electromagnet can keep the magnetic field above it as strong as the PMs', meanwhile feasible for design and manufacture. This work provides valuable references for the future design in non-mechanical PMG turnout.

Adaptive suspension strategy for a double wishbone suspension through camber and toe optimization

Directory of Open Access Journals (Sweden)

C. Kavitha

2018-02-01

Full Text Available A suspension system is responsible for the safety of vehicle during its manoeuvre. It serves the dual purpose of providing stability to the vehicle while providing a comfortable ride quality to the occupants. Recent trends in suspension system have focused on improving comfort and handling of vehicles while keeping the cost, space and feasibility of manufacturing in the constraint. This paper proposes a method for improving handling characteristics of a vehicle by controlling camber and toe angle using variable length arms in an adaptive manner. In order to study the effect of dynamic characteristics of the suspension system, a simulation study has been done in this work. A quarter car physical model with double wishbone suspension geometry is modelled in SolidWorks. It is then imported and simulated using SimMechanics platform in MATLAB. The output characteristics of the passive system (without variable length arms were validated on MSC ADAMS software. The adaptive system intends to improve vehicle handling characteristics by controlling the camber and toe angles. This is accomplished by two telescopic arms with an actuator which changes the camber and toe angle of the wheel dynamically to deliver best possible traction and manoeuvrability. Two PID controllers are employed to trigger the actuators based on the camber and toe angle from the sensors for reducing the error existing between the actual and desired value. The arms are driven by actuators in a closed loop feedback manner with help of a separate control system. Comparison between active and passive systems is carried out by analysing graphs of various parameters obtained from MATLAB simulation. From the results, it is observed that there is a reduction of 58% in the camber and 96% in toe gain. Hence, the system provides the scope of considerable adaptive strategy in controlling dynamic characteristics of the suspension system.

A new pneumatic suspension system with independent stiffness and ride height tuning capabilities

Science.gov (United States)

Yin, Zhihong; Khajepour, Amir; Cao, Dongpu; Ebrahimi, Babak; Guo, Konghui

2012-12-01

This paper introduces a new pneumatic spring for vehicle suspension systems, allowing independent tuning of stiffness and ride height according to different vehicle operating conditions and driver preferences. The proposed pneumatic spring comprises a double-acting pneumatic cylinder, two accumulators and a tuning subsystem. This paper presents a detailed description of the pneumatic spring and its working principle. The mathematical model is established based on principles of thermo and fluid dynamics. An experimental setup has been designed and fabricated for testing and evaluating the proposed pneumatic spring. The analytical and experimental results confirm the capability of the new pneumatic spring system for independent tuning of stiffness and ride height. The mathematical model is verified and the capabilities of the pneumatic spring are further proved. It is concluded that this new pneumatic spring provides a more flexible suspension design alternative for meeting various conflicting suspension requirements for ride comfort and performance.

Electromagnetically induced transparency in an open multilevel system

International Nuclear Information System (INIS)

Li Tian; Lu Meiju; Weinstein, Jonathan D.

2011-01-01

Electromagnetically induced transparency in a multilevel system is investigated in 173 Yb. The level structure investigated is ''open'' in that the light that gives rise to the transparency also resonantly couples the atoms to excited states which do not exhibit electromagnetically induced transparency. The resulting reduction of transparency is investigated experimentally and theoretically. It is found that, while the transparency is poor in certain regimes, it can be made to perform arbitrarily well in the limit of a large intensity imbalance between the optical fields.

Three-dimensional Locomotion and Drilling Microrobot Using Electromagnetic Actuation System

International Nuclear Information System (INIS)

Li, Girl; Choi, Hyun Chul; Cha, Kyoung Rae; Jeong, Se Mi; Park, Jong Oh; Park, Suk Ho

2011-01-01

In this study, a novel electromagnetic microrobot system with locomotion and drilling functions in three dimensional space was developed. Because of size limitations, the microrobot does not have actuator, battery, and controller. Therefore, an electromagnetic actuation (EMA) system was used to drive the robot. The proposed EMA system consists of three rectangular Helmholtz coil pairs in x-, y- and z-axes and a Maxwell coil pair in the z-axis. The magnetic field generated in the EMA coil system could be controlled by the input current of the EMA coil. Finally, through various experiments, the locomotion and drilling performances of the proposed EMA microrobot system were verified

Three-dimensional Locomotion and Drilling Microrobot Using Electromagnetic Actuation System

Energy Technology Data Exchange (ETDEWEB)

Li, Girl; Choi, Hyun Chul; Cha, Kyoung Rae; Jeong, Se Mi; Park, Jong Oh; Park, Suk Ho [Chonnam National University, Gwangju (Korea, Republic of)

2011-12-15

In this study, a novel electromagnetic microrobot system with locomotion and drilling functions in three dimensional space was developed. Because of size limitations, the microrobot does not have actuator, battery, and controller. Therefore, an electromagnetic actuation (EMA) system was used to drive the robot. The proposed EMA system consists of three rectangular Helmholtz coil pairs in x-, y- and z-axes and a Maxwell coil pair in the z-axis. The magnetic field generated in the EMA coil system could be controlled by the input current of the EMA coil. Finally, through various experiments, the locomotion and drilling performances of the proposed EMA microrobot system were verified.

A resonant electromagnetic vibration energy harvester for intelligent wireless sensor systems

Energy Technology Data Exchange (ETDEWEB)

Qiu, Jing, E-mail: jingqiu@cqu.edu.cn; Wen, Yumei; Li, Ping; Liu, Xin; Chen, Hengjia; Yang, Jin [Sensors and Instruments Research Center, College of Optoelectronic Engineering, Chongqing University, Chongqing 400044 (China)

2015-05-07

Vibration energy harvesting is now receiving more interest as a means for powering intelligent wireless sensor systems. In this paper, a resonant electromagnetic vibration energy harvester (VEH) employing double cantilever to convert low-frequency vibration energy into electrical energy is presented. The VEH is made up of two cantilever beams, a coil, and magnetic circuits. The electric output performances of the proposed electromagnetic VEH have been investigated. With the enhancement of turns number N, the optimum peak power of electromagnetic VEH increases sharply and the resonance frequency deceases gradually. When the vibration acceleration is 0.5 g, we obtain the optimum output voltage and power of 9.04 V and 50.8 mW at frequency of 14.9 Hz, respectively. In a word, the prototype device was successfully developed and the experimental results exhibit a great enhancement in the output power and bandwidth compared with other traditional electromagnetic VEHs. Remarkably, the proposed resonant electromagnetic VEH have great potential for applying in intelligent wireless sensor systems.

High-gradient electromagnetic separator with continuous slurry extraction

International Nuclear Information System (INIS)

Dolle, L.

1986-04-01

This kind of separator is operating without matrix in a cascade arrangement of conventional electromagnets. It is most suitable for continuous extraction of paramagnetic particulate solids in liquid suspensions. The water-cooled coils are supported by an iron-yoke with an adjustable air-gap. A one-stage device of laboratory size has been worked out in order to achieve measurements of the magnetic field intensities distributions. Then efficiency measurements were first carried out with a reference magnetite particles suspension in water, without sludge bleeding. As representatives of paramagnetic solids, manganese dioxide, copper oxide and a ruthenium oxide colloid in water are chosen, at concentrations ranging from 100 to 2000 ppm. Efficiencies were measured with continuous and periodical sludge bleedings. Results of such measurements are discussed

Study of Electromagnetic Fields on Cellular Systems Study of Electromagnetic Fields on Cellular Systems

Directory of Open Access Journals (Sweden)

Sergio Solorio-Meza

2012-02-01

Full Text Available Durante las últimas décadas, el interés por explicar el efecto de la radiación no ionizante, como es el caso de los campos electromagnéticos (CEM sobre sistemas celulares ha aumentado considerablemente. En este artículo se describe la interacción que existe entre los CEM y sistemas biológicos. Se discute el efecto de la estimulación electromagnética a diferentes frecuencias e intensidades en cultivos celulares. Resultados preliminares al estimular células de neuroblastomas SK-NSH con campos electromagnéticos de extra baja frecuencia (CEM-EBF, CEM que van del rango de 3 a 30 Hz, indican que se induce un estrés celularque se refleja en variaciones en la expresión de proteínas respecto al grupo de células no estimuladas. En particular, la expresión de las proteínas muestra que los CEM-EBF producen cambios en las proteínas presentes en condiciones normales o basales en las células, es decir, aparecen nuevas proteínas o existe un aumento en la cantidad de ellas.In the last decades the interest to study the effect of non-ionizing radiation, such as the electromagnetic fields (EMF on cellular systems has increased. In this article the interaction between EMF and biological systems is described. An analysis of the effect of the electromagnetic stimulation at different frequencies and intensities on cell cultures is performed. Preliminary results show that the stimulation with extremely low frequency electromagnetic fields (ELF-EMF, EMF from 3 to 30 Hz, on the cellular line of neuroblastomaSK-NSH induces cellular stress. This is reflected by a variation in the proteins expression in comparison with the group of cells no stimulated. In particular, the proteins expression shows that the ELF-EMF produce changes in the current proteins in normal or basal conditionsin the cells, that is, new proteins appear or there is evidence of an increasing in theamount of them.

Electromagnetic wave matching device

International Nuclear Information System (INIS)

Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.

1997-01-01

The present invention provides an electromagnetic wave matching capable of reducing a cost for the transmission system in a system of using electromagnetic waves for plasma heating of a thermonuclear reactor. Namely, incident electromagnetic waves are reflected by using a plurality of phase correction mirrors. The reflected electromagnetic waves are connected to an external transmission system through an exit. The phase correction mirrors have such a shape to receive a plurality of beam-like electromagnetic waves and output electromagnetic waves by the number different from the number of the received electromagnetic wave beams having a predetermined distribution. Further, at least two of the phase correction mirrors have such a shape to change the phase of the electromagnetic waves beams incident to the reflection surface of the phase correction mirrors by a predetermined amount corresponding to the position of the reflection surface. Then, the cost for transmission system can greatly be reduced. (I.S.)

Design and Optimization of Annular Flow Electromagnetic Measurement System for Drilling Engineering

Directory of Open Access Journals (Sweden)

Liang Ge

2018-01-01

Full Text Available Using the downhole annular flow measurement system to get real-time information of downhole annular flow is the core and foundation of downhole microflux control drilling technology. The research work of electromagnetic flowmeter in recent years creates a challenge to the design of downhole annular flow measurement. This paper proposes a design and optimization of annular flow electromagnetic measurement system for drilling engineering based on the finite element method. Firstly, the annular flow measuring and optimization principle are described. Secondly, a simulation model of an annular flow electromagnetic measurement system with two pairs of coil is built based on the fundamental equation of electromagnetic flowmeter by COMSOL. Thirdly, simulations of the structure of excitation system of the measurement system are carried out, and simulations of the size of the electrode’s radius are also carried out based on the optimized structure, and then all the simulation results are analyzed to evaluate the optimization effect based on the evaluation indexes. The simulation results show that optimized shapes of the excitation system and electrode size can yield a better performance in the annular flow measurement.

[Effects of extremely low frequency electromagnetic radiation on cardiovascular system of workers].

Science.gov (United States)

Zhao, Long-yu; Song, Chun-xiao; Yu, Duo; Liu, Xiao-liang; Guo, Jian-qiu; Wang, Chuan; Ding, Yuan-wei; Zhou, Hong-xia; Ma, Shu-mei; Liu, Xiao-dong; Liu, Xin

2012-03-01

To observe the exposure levels of extremely low frequency electromagnetic fields in workplaces and to analyze the effects of extremely low frequency electromagnetic radiation on cardiovascular system of occupationally exposed people. Intensity of electromagnetic fields in two workplaces (control and exposure groups) was detected with EFA-300 frequency electromagnetic field strength tester, and intensity of the noise was detected with AWA5610D integral sound level. The information of health physical indicators of 188 controls and 642 occupationally exposed workers was collected. Data were analyzed by SPSS17.0 statistic software. The intensity of electric fields and the magnetic fields in exposure groups was significantly higher than that in control group (P 0.05). The results of physical examination showed that the abnormal rates of HCY, ALT, AST, GGT, ECG in the exposure group were significantly higher than those in control group (P 0.05). Exposure to extremely low frequency electromagnetic radiation may have some effects on the cardiovascular system of workers.

Wireless system controlling of electromagnetic wave distribution in nuclear power plant use

International Nuclear Information System (INIS)

Kuroda, Hidehiko; Kume, Naoto; Oshima, Tomomi; Takakura, Kei; Oda, Naotaka; Hasegawa, Takeshi; Odanaka, Shigeru

2017-01-01

Recently, wireless technologies have rapidly spread by cellular phones, smartphones and tablet devices. Wireless systems in the nuclear power plant are expected to bring various advantages such as shortening of the inspection time, online monitoring, remote control and cable reduction, etc. However, wireless systems have hardly applied to the nuclear power plant, from the point of security and electromagnetic interference (EMI). We propose a new wireless system controlling automatically electromagnetic wave distribution. In our wireless system, the transmitter / receiver modules automatically measure the wave strength and adjust the power and directivity of the wave, resulting in wireless communication only in target zones, i.e. non-influence to safety-related instruments and non-leakage of information. We will present the algorithm of the electromagnetic wave controlling and experimental results about the proposed system. (author)

An efficient recursive least square-based condition monitoring approach for a rail vehicle suspension system

Science.gov (United States)

Liu, X. Y.; Alfi, S.; Bruni, S.

2016-06-01

A model-based condition monitoring strategy for the railway vehicle suspension is proposed in this paper. This approach is based on recursive least square (RLS) algorithm focusing on the deterministic 'input-output' model. RLS has Kalman filtering feature and is able to identify the unknown parameters from a noisy dynamic system by memorising the correlation properties of variables. The identification of suspension parameter is achieved by machine learning of the relationship between excitation and response in a vehicle dynamic system. A fault detection method for the vertical primary suspension is illustrated as an instance of this condition monitoring scheme. Simulation results from the rail vehicle dynamics software 'ADTreS' are utilised as 'virtual measurements' considering a trailer car of Italian ETR500 high-speed train. The field test data from an E464 locomotive are also employed to validate the feasibility of this strategy for the real application. Results of the parameter identification performed indicate that estimated suspension parameters are consistent or approximate with the reference values. These results provide the supporting evidence that this fault diagnosis technique is capable of paving the way for the future vehicle condition monitoring system.

Design and characterization of an electromagnetic energy harvester for vehicle suspensions

International Nuclear Information System (INIS)

Zuo, Lei; Scully, Brian; Shestani, Jurgen; Zhou, Yu

2010-01-01

During the everyday usage of an automobile, only 10–16% of the fuel energy is used to drive the car—to overcome the resistance from road friction and air drag. One important loss is the dissipation of vibration energy by shock absorbers in the vehicle suspension under the excitation of road irregularity and vehicle acceleration or deceleration. In this paper we design, characterize and test a retrofit regenerative shock absorber which can efficiently recover the vibration energy in a compact space. Rare-earth permanent magnets and high permeable magnetic loops are used to configure a four-phase linear generator with increased efficiency and reduced weight. The finite element method is used to analyze the magnetic field and guide the design optimization. A theoretical model is created to analytically characterize the waveforms and regenerated power of the harvester at various vibration amplitudes, frequencies, equilibrium positions and design parameters. It was found that the waveform and RMS voltage of the individual coils will depend on the equilibrium position but the total energy will not. Experimental studies of a 1:2 scale prototype are conducted and the results agree very well with the theoretical predictions. Such a regenerative shock absorber will be able to harvest 16–64 W power at 0.25–0.5 m s −1 RMS suspension velocity

Electromagnetically shielded building

Energy Technology Data Exchange (ETDEWEB)

Takahashi, T; Nakamura, M; Yabana, Y; Ishikawa, T; Nagata, K

1992-04-21

This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs.

Electromagnetically shielded building

International Nuclear Information System (INIS)

Takahashi, T.; Nakamura, M.; Yabana, Y.; Ishikawa, T.; Nagata, K.

1992-01-01

This invention relates to a building having an electromagnetic shield structure well-suited for application to an information network system utilizing electromagnetic waves, and more particularly to an electromagnetically shielded building for enhancing the electromagnetic shielding performance of an external wall. 6 figs

The Design and Simulation of the Modular Vehicle Air Suspension Height Control System Based on ECAS

Directory of Open Access Journals (Sweden)

Yang Peigang

2014-02-01

Full Text Available Based on ECAS, this paper intended to develop a modular air suspension height control system with WABCO4728800010 two-position three way solenoid valves and Free scale MC9S12D64 microprocessor as its core components. And a simulation test was conducted in MATLAB/Simulink environment. The air suspension height control strategy of this system was divided into four modules: start control module, dynamic adjustment module, manual adjustment module and errors adjustment module, which were controlled by module select switch. Simulation tests indicated that the air suspension height control strategy is featured by its logical control accuracy and debug convenience, and the modular design greatly reduced the system complexity and software development cycle and costs as well.

Adaptive neural networks control for camera stabilization with active suspension system

Directory of Open Access Journals (Sweden)

Feng Zhao

2015-08-01

Full Text Available The camera always suffers from image instability on the moving vehicle due to unintentional vibrations caused by road roughness. This article presents an adaptive neural network approach mixed with linear quadratic regulator control for a quarter-car active suspension system to stabilize the image captured area of the camera. An active suspension system provides extra force through the actuator which allows it to suppress vertical vibration of sprung mass. First, to deal with the road disturbance and the system uncertainties, radial basis function neural network is proposed to construct the map between the state error and the compensation component, which can correct the optimal state-feedback control law. The weights matrix of radial basis function neural network is adaptively tuned online. Then, the closed-loop stability and asymptotic convergence performance is guaranteed by Lyapunov analysis. Finally, the simulation results demonstrate that the proposed controller effectively suppresses the vibration of the camera and enhances the stabilization of the entire camera, where different excitations are considered to validate the system performance.

Immunizing digital systems against electromagnetic interference

International Nuclear Information System (INIS)

Ewing, P.D.; Korsah, K.; Antonescu, C.

1993-01-01

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Second, a test and evaluation program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate test limits to ensure that the circuit or system under test meets the recommended guidelines. Test and evaluation should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation problems associated with EMI will be greatly reduced

Immunizing digital systems against electromagnetic interference

International Nuclear Information System (INIS)

Ewing, P.D.; Korsah, K.; Antonescu, C.

1993-01-01

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Secondly, a test and evaluation program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate test limits to ensure that the circuit or system under test meets the recommended guidelines. Test and evaluation should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation problems associated with EMI will be greatly reduced

Simulation study of localization of electromagnetic waves in two-dimensional random dipolar systems

International Nuclear Information System (INIS)

Wang, Ken Kang-Hsin; Ye Zhen

2003-01-01

We study the propagation and scattering of electromagnetic waves by random arrays of dipolar cylinders in a uniform medium. A set of self-consistent equations, incorporating all orders of multiple scattering of the electromagnetic waves, is derived from first principles and then solved numerically for electromagnetic fields. For certain ranges of frequencies, spatially localized electromagnetic waves appear in such a simple but realistic disordered system. Dependence of localization on the frequency, radiation damping, and filling factor is shown. The spatial behavior of the total, coherent, and diffusive waves is explored in detail, and found to comply with a physical intuitive picture. A phase diagram characterizing localization is presented, in agreement with previous investigations on other systems

Simulation study of localization of electromagnetic waves in two-dimensional random dipolar systems.

Science.gov (United States)

Wang, Ken Kang-Hsin; Ye, Zhen

2003-12-01

We study the propagation and scattering of electromagnetic waves by random arrays of dipolar cylinders in a uniform medium. A set of self-consistent equations, incorporating all orders of multiple scattering of the electromagnetic waves, is derived from first principles and then solved numerically for electromagnetic fields. For certain ranges of frequencies, spatially localized electromagnetic waves appear in such a simple but realistic disordered system. Dependence of localization on the frequency, radiation damping, and filling factor is shown. The spatial behavior of the total, coherent, and diffusive waves is explored in detail, and found to comply with a physical intuitive picture. A phase diagram characterizing localization is presented, in agreement with previous investigations on other systems.

Electromagnetic drive of the control and protection system of a nuclear reactor

International Nuclear Information System (INIS)

Zav'yalova, G.I.

1983-01-01

The design and operating principle of an electromagnetic drive with a linear synchronous reaction motor are described. At the present time, electromagnetic control mechanisms using linear electric motors are finding increasingly widespread application as drives for the control and protection system of nuclear reactors. In these drives there is a functional mergence of the electromagnetic mechanism with the final control element; these drives, therefore, have advantages over electromechanical drives

VETEM -- a very early time electromagnetic system -- year 2

International Nuclear Information System (INIS)

Pellerin, L.; Pfeifer, M.C.; Labson, V.F.

1996-01-01

In electrically conductive conditions common in environmental characterization studies the minimum depth of investigation for traditional electromagnetic (EM) sounding techniques is roughly 5 meters, while ground penetrating radar (GPR) systems often investigate no more than the top meter or so when clay minerals are present in the soil. Bridging this gap is essential to the characterization of buried waste, contaminant plumes, and other environmental and hydrogeological targets located in the shallow subsurface. The Very Early Time Electromagnetic (VETEM) system is designed to ascertain the conductivity and dielectric properties of the shallow subsurface in conductive terrain. Hence, the one-dimensional (1-D) and three-dimensional (3-D) numerical modeling algorithms, developed in the first year of the project, contain the full solution to the EM problem including both displacement and conduction currents. The VETEM system fills a gap between EM and GPR, but all three methods are necessary to successfully image the shallow subsurface. To achieve the goal of fully 3-D subsurface imaging, the VETEM project is hosting the Electromagnetic Integrated Demonstration (EMID) at the Idaho National Engineering Laboratory's Cold Test Pit (INEL's CTP). Over a dozen EM systems will acquire data over the same survey area for interpretation in conjunction with the VETEM team. The prototype time-domain instrument employs a magnetic dipole transmitter and receiver and operates from 10 nano-second to a micro-second. The USGS high frequency sounder (HFS), which served as the VETEM proof-of-concept, uses the same antenna geometry as the time-domain instrument and acquires data from 30 kHz to 30 MHz. The first VETEM survey was recently conducted at the INEL's CTP as a part of the EMID. The electromagnetic migration technique is being investigated for interpretation of the VETEM data

Fast Turn-off Mine Transient Electromagnetic Transmitter System

Directory of Open Access Journals (Sweden)

ZHENG Xiao-Liang

2014-05-01

Full Text Available For solving problems such as short turn-off time, high linear degree of falling edge, measurement of turn-off time and influence of primary signals for transient electromagnetic transmitter, and restrictions because of the environmental conditions of underground coal mine, this thesis aims at designing a new transient electromagnetic transmitter system suitable for coal mine. Supported by damping absorption circuit, such system applies small volume, sectional transmitting coil, with features of short turn-off time, high linear degree of current falling edge. It uses the transmitter monitoring circuit, which accurately measures turn-off time and simultaneously records the current value changes after turn-off, thus to eliminate the influence of primary field as well as to restore earlier secondary field signals for reference and finally to improve the ability to detect the shallow structure. It turns out that the new system has a shorter turn-off time, a higher linear degree of current falling and more accurate data record of turn-off current.

Model predictive control of an air suspension system with damping multi-mode switching damper based on hybrid model

Science.gov (United States)

Sun, Xiaoqiang; Yuan, Chaochun; Cai, Yingfeng; Wang, Shaohua; Chen, Long

2017-09-01

This paper presents the hybrid modeling and the model predictive control of an air suspension system with damping multi-mode switching damper. Unlike traditional damper with continuously adjustable damping, in this study, a new damper with four discrete damping modes is applied to vehicle semi-active air suspension. The new damper can achieve different damping modes by just controlling the on-off statuses of two solenoid valves, which makes its damping adjustment more efficient and more reliable. However, since the damping mode switching induces different modes of operation, the air suspension system with the new damper poses challenging hybrid control problem. To model both the continuous/discrete dynamics and the switching between different damping modes, the framework of mixed logical dynamical (MLD) systems is used to establish the system hybrid model. Based on the resulting hybrid dynamical model, the system control problem is recast as a model predictive control (MPC) problem, which allows us to optimize the switching sequences of the damping modes by taking into account the suspension performance requirements. Numerical simulations results demonstrate the efficacy of the proposed control method finally.

Electromagnetic compatibility of tools and automated process control systems of NPP units

International Nuclear Information System (INIS)

Alpeev, A.S.

1994-01-01

Problems of electromagnetic compatibility of automated process control subsystems in NPP units are discussed. It is emphasized, that at the stage of development of request for proposal for each APC subsystem special attention should be paid to electromagnetic situation in specific room and requirements to the quality of functions performed by the system. Besides, requirements to electromagnetic compatibility tests at the work stations should be formulated, and mock-ups of the subsystems should be tested

Suspension for the low frequency facility

CERN Document Server

Cella, G; Di Virgilio, A; Gaddi, A; Viceré, A

2000-01-01

We introduce the working principles of the VIRGO Low Frequency Facility (LFF), whose main aim is the measurement of the thermal noise in the VIRGO suspension system. We evaluate the displacement thermal noise of a mirror, which is an intermediate element of a double pendulum suspension system. This double pendulum will be suspended to the last stage of a VIRGO Super-Attenuator (SA), the prototype VIRGO suspension system being tested at the Pisa section of INFN. In the proposed configuration, we evaluate the spectrum of the thermal noise for different choices of the parameters: based on this study, we comment on the future directions to be undertaken in the LFF experiment.

T-S Fuzzy Model Based Control Strategy for the Networked Suspension Control System of Maglev Train

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Guang He

2015-01-01

Full Text Available The control problem for the networked suspension control system of maglev train with random induced time delay and packet dropouts is investigated. First, Takagi-Sugeno (T-S fuzzy models are utilized to represent the discrete-time nonlinear networked suspension control system, and the parameters uncertainties of the nonlinear model have also been taken into account. The controllers take the form of parallel distributed compensation. Then, a sufficient condition for the stability of the networked suspension control system is derived. Based on the criteria, the state feedback fuzzy controllers are obtained, and the controller gains can be computed by using MATLAB LMI Toolbox directly. Finally, both the numerical simulations and physical experiments on the full-scale single bogie of CMS-04 maglev train have been accomplished to demonstrate the effectiveness of this proposed method.

Establishment of Aquilaria malaccensis Callus, cell suspension and adventitious root systems

International Nuclear Information System (INIS)

Norazlina Noordin; Rusli Ibrahim

2010-01-01

Aquilaria malaccensis is a tropical forest tree from the family Thymelaeaceae, an endangered forest species and was listed in CITES since 1995. Locally known as Pokok Karas, this tree produces agar wood or gaharu, a highly valuable, resinous and fragrant forest product. Karas has been highly recognized for its vast medicinal values and gaharu has been widely use for perfumery, incense and religious purposes. The phyto chemical studies of agar wood showed that Sesqui terpenoid and Phenyl ethy chromone derivatives are the principal compounds that have anti allergic and anti microbe activities. Cell and organ culture systems provide large scale production of biomass and offers feasibilities for the production of secondary metabolites. This paper describes the work done for establishing reproducible systems for callus initiation and production of cell suspension cultures as well as production of adventitious roots that will later be amenable for the production of secondary metabolites of A. malaccensis. Hence, further manipulation with Methyl Jasmonate, a chemical elicitor could be done to induce secondary metabolites using callus, cell suspension and adventitious roots systems. (author)

Electromagnetic compatibility design and cabling system rules

International Nuclear Information System (INIS)

Raimbourg, J.

2009-01-01

This report is devoted to establish EMC (Electromagnetic Compatibility) design and cabling system rules. It is intended for hardware designers in charge of designing electronic maps or integrating existing materials into a comprehensive system. It is a practical guide. The rules described in this document do not require enhanced knowledge of advanced mathematical or physical concepts. The key point is to understand phenomena with a pragmatic approach to highlight the design and protection rules. (author)

A Study on the Influence of Electromagnetic Radiation on Nervous System

Directory of Open Access Journals (Sweden)

Dong Xinlin

2015-01-01

Full Text Available Being applied widely, electromagnetic wave is closely related with our life. But this material has brought pollutions to the environment as well as influences on functions of organisms. In order to explore the influence of electromagnetic radiation on nervous system, this paper takes adult mice on 35th day as research objects, designs a water maze experiment and explores features of escaping latency of mice in the control group and in the group with radiation. In this research, methods of building a GHz TEM cell and a simulation model of mouse head with AutoCAD 2010 and XFDTD are provided, verifying that the simulation model meets the needs of the experiment. It concludes that the electromagnetic radiation causes memory deterioration of mice, and exerts its certain influence on nervous system.

Effects of chronic exposure to electromagnetic waves on the auditory system.

Science.gov (United States)

Özgür, Abdulkadir; Tümkaya, Levent; Terzi, Suat; Kalkan, Yıldıray; Erdivanlı, Özlem Çelebi; Dursun, Engin

2015-08-01

The results support that chronic electromagnetic field exposure may cause damage by leading to neuronal degeneration of the auditory system. Numerous researches have been done about the risks of exposure to the electromagnetic fields that occur during the use of these devices, especially the effects on hearing. The aim of this study is to evaluate the effects of the electromagnetic waves emitted by the mobile phones through the electrophysiological and histological methods. Twelve adult Wistar albino rats were included in the study. The rats were divided into two groups of six rats. The study group was exposed to the electromagnetic waves over a period of 30 days. The control group was not given any exposure to the electromagnetic fields. After the completion of the electromagnetic wave application, the auditory brainstem responses of both groups were recorded under anesthesia. The degeneration of cochlear nuclei was graded by two different histologists, both of whom were blinded to group information. The histopathologic and immunohistochemical analysis showed neuronal degeneration signs, such as increased vacuolization in the cochlear nucleus, pyknotic cell appearance, and edema in the group exposed to the electromagnetic fields compared to the control group. The average latency of wave in the ABR was similar in both groups (p > 0.05).

Analyses of electromagnetic and piezoelectric systems for efficient vibration energy harvesting

Science.gov (United States)

Hadas, Z.; Smilek, J.; Rubes, O.

2017-05-01

The paper deals with analyses and evaluation of vibration energy harvesting systems which are based on electromagnetic and piezoelectric physical principles off electro-mechanical conversion. Energy harvesting systems are associated with wireless sensors and a monitoring of engineering objects. The most of engineering objects operate with unwanted mechanical vibrations. However, vibrations could provide an ambient source of energy which is converted into useful electricity. The use of electromagnetic and piezoelectric vibration energy harvesters is analyzed in this paper. Thee evaluated output power is used for a choice of the efficient system with respect to the character of vibrations and thee required power output.

ELECTROMAGNETIC SAFETY OF ELECTRIC TRANSPORT SYSTEMS: MAIN SOURCES AND PARAMETERS OF MAGNETIC FIELDS

Directory of Open Access Journals (Sweden)

N. G. Ptitsyna

2013-03-01

Full Text Available Magnetic fields produced by electric drive vehicles may break electromagnetic safety. For electromagnetic safety and electromagnetic compatibility knowledge about characteristics and sources of magnetic fields in the electric transport is necessary. The article deals with analysis of available data about magnetic fields in electric cars and comparison with results of our measurements carried out in the other types of electrified transport systems.

Electromagnetic Coupling of Ocean Flow with the Earth System

Directory of Open Access Journals (Sweden)

Robert Tyler

2015-01-01

Full Text Available The ocean is electromagnetically coupled with the Earth System. This results in momentum transfer, as well as a participation by the ocean in the _ observable electric and magnetic fields. The coupling is typically quite weak and quantitative analyses indicate that many of these connections may be discounted when considering the transfer of momentum. But because of systematic effects there are also cases where an immediate discount is not justified and electromagnetic transfer of ocean momentum should remain within the realm of consideration. For practical considerations, even if the coupling is weak these effects are phenomenologically important because the electric and magnetic fields associated with this coupling offer an observational means for inferring the ocean flow. While in situ measurements of the electric field have long been used to measure ocean transport, new opportunities for remote sensing ocean flow through ground and space magnetic observatories are now being considered. In this article a brief update of the status of these observational methods is given. Extending beyond these established elements of the _ electromagnetic involvement, an attempt is made to provide a quantitative discussion of lesser considered elements of the _ electromagnetic coupling with the mantle and fluid core.

An Ultra-low Frequency Modal Testing Suspension System for High Precision Air Pressure Control

Directory of Open Access Journals (Sweden)

Qiaoling YUAN

2014-05-01

Full Text Available As a resolution for air pressure control challenges in ultra-low frequency modal testing suspension systems, an incremental PID control algorithm with dead band is applied to achieve high-precision pressure control. We also develop a set of independent hardware and software systems for high-precision pressure control solutions. Taking control system versatility, scalability, reliability, and other aspects into considerations, a two-level communication employing Ethernet and CAN bus, is adopted to complete such tasks as data exchange between the IPC, the main board and the control board ,and the pressure control. Furthermore, we build a single set of ultra-low frequency modal testing suspension system and complete pressure control experiments, which achieve the desired results and thus confirm that the high-precision pressure control subsystem is reasonable and reliable.

V-TECS Guide for Auto Mechanics: Suspension Systems, Brakes and Steering.

Science.gov (United States)

Moore, Charles G.; And Others

The materials in this document are an extension of a catalog of occupational duties, tasks, and performance objectives relevant to maintaining automotive suspension systems, brakes, and steering mechanisms. This document provides the following for each occupational task within each duty: (1) a standard of performance; (2) the conditions under…

Study on the adjustment capability of the excitation system located inside superconducting machine electromagnetic shield

Science.gov (United States)

Xia, D.; Xia, Z.

2017-12-01

The ability for the excitation system to adjust quickly plays a very important role in maintaining the normal operation of superconducting machines and power systems. However, the eddy currents in the electromagnetic shield of superconducting machines hinder the exciting magnetic field change and weaken the adjustment capability of the excitation system. To analyze this problem, a finite element calculation model for the transient electromagnetic field with moving parts is established. The effects of three different electromagnetic shields on the exciting magnetic field are analyzed using finite element method. The results show that the electromagnetic shield hinders the field changes significantly, the better its conductivity, the greater the effect on the superconducting machine excitation.

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXI, I--MAINTAINING THE AIR SYSTEM--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING REAR END SUSPENSION.

Science.gov (United States)

Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM AND REAR AXLE SUSPENSION USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) AIR INDUCTION AND EXHAUST SYSTEM, (2) VALVE MECHANISM, (3) TROUBLESHOOTING THE AIR SYSTEM, (4) PURPOSE OF VEHICLE SUSPENSION, (5) TANDEM…

Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles.

Science.gov (United States)

Abid, Haider J; Chen, Jie; Nassar, Ameen A

2015-01-01

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

Mirror suspension system for the TAMA SAS

CERN Document Server

Takamori, A; Bertolini, A; Cella, G; DeSalvo, R; Fukushima, M; Iida, Y; Jacquier, F; Kawamura, S; Marka, S; Nishi, Y; Numata, K; Sannibale, V; Somiya, K; Takahashi, R; Tariq, H; Tsubono, K; Ugas, J; Viboud, N; Yamamoto, H; Yoda, T; Wang Chen Yang

2002-01-01

Several R and D programmes are ongoing to develop the next generation of interferometric gravitational wave detectors providing the superior sensitivity desired for refined astronomical observations. In order to obtain a wide observation band at low frequencies, the optics need to be isolated from the seismic noise. The TAMA SAS (seismic attenuation system) has been developed within an international collaboration between TAMA, LIGO, and some European institutes, with the main objective of achieving sufficient low-frequency seismic attenuation (-180 dB at 10 HZ). The system suppresses seismic noise well below the other noise levels starting at very low frequencies above 10 Hz. It also includes an active inertial damping system to decrease the residual motion of the optics enough to allow a stable operation of the interferometer. The TAMA SAS also comprises a sophisticated mirror suspension subsystem (SUS). The SUS provides support for the optics and vibration isolation complementing the SAS performance. The SU...

Electromagnetic wave matching device

International Nuclear Information System (INIS)

Hirata, Yosuke; Mitsunaka, Yoshika; Hayashi, Ken-ichi; Ito, Yasuyuki.

1997-01-01

The present invention provides a matching device capable of increasing an efficiency of combining beams of electromagnetic waves outputted from an output window of a gyrotron which is expected for plasma heating of a thermonuclear reactor and an electromagnetic wave transmission system as high as possible. Namely, an electromagnetic wave matching device reflects beams of electromagnetic waves incident from an inlet by a plurality of phase correction mirrors and combines them to an external transmission system through an exit. In this case, the phase correction mirrors change the phase of the beams of electromagnetic waves incident to the phase correction mirrors by a predetermined amount corresponding to the position of the reflection mirrors. Then, the beams of electromagnetic waves outputted, for example, from a gyrotron can properly be shaped as desired for the intensity and the phase. As a result, combination efficiency with the transmission system can be increased. (I.S.)

FxLMS Method for Suppressing In-Wheel Switched Reluctance Motor Vertical Force Based on Vehicle Active Suspension System

Directory of Open Access Journals (Sweden)

Yan-yang Wang

2014-01-01

Full Text Available The vibration of SRM obtains less attention for in-wheel motor applications according to the present research works. In this paper, the vertical component of SRM unbalanced radial force, which is named as SRM vertical force, is taken into account in suspension performance for in-wheel motor driven electric vehicles (IWM-EV. The analysis results suggest that SRM vertical force has a great effect on suspension performance. The direct cause for this phenomenon is that SRM vertical force is directly exerted on the wheel, which will result in great variation in tyre dynamic load and the tyre will easily jump off the ground. Furthermore, the frequency of SRM vertical force is broad which covers the suspension resonance frequencies. So it is easy to arouse suspension resonance and greatly damage suspension performance. Aiming at the new problem, FxLMS (filtered-X least mean square controller is proposed to improve suspension performance. The FxLMS controller is based on active suspension system which can generate the controllable force to suppress the vibration caused by SRM vertical force. The conclusion shows that it is effective to take advantage of active suspensions to reduce the effect of SRM vertical force on suspension performance.

The effects of suction and pin/lock suspension systems on transtibial amputees' gait performance.

Directory of Open Access Journals (Sweden)

Hossein Gholizadeh

Full Text Available BACKGROUND: The suction sockets that are commonly prescribed for transtibial amputees are believed to provide a better suspension than the pin/lock systems. Nevertheless, their effect on amputees' gait performance has not yet been fully investigated. The main intention of this study was to understand the potential effects of the Seal-in (suction and the Dermo (pin/lock suspension systems on amputees' gait performance. METHODOLOGY/PRINCIPAL FINDINGS: Ten unilateral transtibial amputees participated in this prospective study, and two prostheses were fabricated for each of them. A three-dimensional motion analysis system was used to evaluate the temporal-spatial, kinematics and kinetics variables during normal walking. We also asked the participants to complete some part of Prosthesis Evaluation Questionnaire (PEQ regarding their satisfaction and problems with both systems. The results revealed that there was more symmetry in temporal-spatial parameters between the prosthetic and sound limbs using the suction system. However, the difference between two systems was not significant (p<0.05. Evaluation of kinetic data and the subjects' feedback showed that the participants had more confidence using the suction socket and the sockets were more fit for walking. Nevertheless, the participants had more complaints with this system due to the difficulty in donning and doffing. CONCLUSION: It can be concluded that even though the suction socket could create better suspension, fit, and gait performance, overall satisfaction was higher with the pin/lock system due to easy donning and doffing of the prosthesis. TRIAL REGISTRATION: irct.ir IRCT2014012816395N1.

76 FR 41855 - Columbus Geographic Systems (GIS) Ltd.; Order of Suspension of Trading

Science.gov (United States)

2011-07-15

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Columbus Geographic Systems (GIS) Ltd.; Order of Suspension of Trading July 13, 2011. It appears to the Securities and Exchange Commission that... Systems (GIS) Ltd. because it has not filed any periodic reports since the period ended June 30, 2008. The...

Optimal design of a for middle-low-speed maglev trains

Science.gov (United States)

Xiao, Song; Zhang, Kunlun; Liu, Guoqing; Jing, Yongzhi; Sykulski, Jan K.

2018-04-01

A middle-low-speed maglev train is supported by an electromagnetic force between the suspension electromagnet (EM) and the steel rail and is driven by a linear induction motor. The capability of the suspension system has a direct bearing on safety and the technical and economic performance of the train. This paper focuses on the dependence of the electromagnetic force on the structural configuration of the EM with the purpose of improving performance of a conventional EM. Finally, a novel configuration is proposed of a hybrid suspension magnet, which combines permanent magnets and coils, in order to increase the suspension force while reducing the suspension power loss.

Optimal design of a for middle-low-speed maglev trains

Directory of Open Access Journals (Sweden)

Xiao Song

2018-04-01

Full Text Available A middle-low-speed maglev train is supported by an electromagnetic force between the suspension electromagnet (EM and the steel rail and is driven by a linear induction motor. The capability of the suspension system has a direct bearing on safety and the technical and economic performance of the train. This paper focuses on the dependence of the electromagnetic force on the structural configuration of the EM with the purpose of improving performance of a conventional EM. Finally, a novel configuration is proposed of a hybrid suspension magnet, which combines permanent magnets and coils, in order to increase the suspension force while reducing the suspension power loss.

Magnetic Suspension Technology Workshop

International Nuclear Information System (INIS)

Keckler, C.R.; Groom, N.J.; Britcher, C.P.

1993-01-01

In order to identify the state of magnetic suspension technology in such areas as rotating systems, pointing of experiments or subsystems, payload isolation, and superconducting materials, a workshop on Magnetic Suspension Technology was held at the Langley Research Center in Hampton, Virginia, on 2-4 Feb. 1988. The workshop included five technical sessions in which a total of 24 papers were presented. The technical sessions covered the areas of pointing, isolation, and measurement, rotating systems, modeling and control, and superconductors. A list of attendees is provided. Separate abstracts have been prepared for articles from this report

Three-axial evaluation of whole-body vibration in agricultural telehandlers: The effects of an active cab-suspension system.

Science.gov (United States)

Caffaro, Federica; Preti, Christian; Micheletti Cremasco, Margherita; Cavallo, Eugenio

2017-10-01

Agricultural and earth-moving machinery operators are particularly exposed to whole-body vibration (WBV), which has severe effects on health and affects comfort and performance. Few studies have investigated vibrational safety and comfort issues in telescopic handlers. These vehicles are widespread in many off-road applications-such as construction, agriculture, and mining-used to handle loads and to lift persons and equipment. This study investigated the effects of an active hydro-pneumatic cab-suspension system fitted to a telehandler on a driver's vibration exposure along the x-, y-, and z-axes, through both objective and subjective assessments. Sixteen healthy professional telehandler drivers took part in the study. Objective measurements were acquired at the operator's seat, and subjective ratings were taken while participants drove the telehandler with either a deactivated or activated suspension system at 12 kph on an ISO 5008 smooth track. The results showed that the activation of the cab-suspension system reduced the root-mean-square acceleration along the x- and z-axes (p =.038 and p =.000, respectively). Moreover, the frequency analysis showed a reduction in the acceleration along the z-axis in the range of 2-25 Hz (p suspension systems are discussed.

Macrostructure of smectite-water systems. Influence of anionic poly-electrolytes on the organisation of montmorillonite suspensions

International Nuclear Information System (INIS)

Morvan, Mikel

1993-01-01

In its first part, this research thesis reports a bibliographical study which aimed at highlighting the main aspects of smectite swelling, discusses the organisation of smectite suspension, and briefly presents the knowledge on clay-polymer mixtures. Then, the author describes the method he used to characterise clay suspensions (relaxation, MNR, osmometric techniques, small-angle X-ray diffraction), and theoretical elements required to interpret results. He addresses more particularly the organisation of smectite-water systems with either a natural smectite (montmorillonite) or a synthetic one (laponite) which have different geometries. The last part addresses the interactions between a montmorillonite suspension and sodium polyacrylates. The author, based on the use of small-angle X-ray diffraction and the measurement of the polyelectrolyte osmotic pressure, proposes a new interpretation of the action mechanism of an anionic polyelectrolyte of low molecular mass within a montmorillonite suspension

Applied Electromagnetics

Energy Technology Data Exchange (ETDEWEB)

Yamashita, H; Marinova, I; Cingoski, V [eds.

2002-07-01

These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics.

Applied Electromagnetics

International Nuclear Information System (INIS)

Yamashita, H.; Marinova, I.; Cingoski, V.

2002-01-01

These proceedings contain papers relating to the 3rd Japanese-Bulgarian-Macedonian Joint Seminar on Applied Electromagnetics. Included are the following groups: Numerical Methods I; Electrical and Mechanical System Analysis and Simulations; Inverse Problems and Optimizations; Software Methodology; Numerical Methods II; Applied Electromagnetics

Radiating Frohlich system as a model of cellular electromagnetism

Czech Academy of Sciences Publication Activity Database

Šrobár, Fedor

2015-01-01

Roč. 34, č. 4 (2015), s. 355-360 ISSN 1536-8378 Institutional support: RVO:67985882 Keywords : electromagnetic radiation * Fröhlich systems * cell physiology Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.208, year: 2015

Hysteresis-induced bifurcation and chaos in a magneto-rheological suspension system under external excitation

International Nuclear Information System (INIS)

Zhang Hailong; Zhang Ning; Wang Enrong; Min Fuhong

2016-01-01

The magneto-rheological damper (MRD) is a promising device used in vehicle semi-active suspension systems, for its continuous adjustable damping output. However, the innate nonlinear hysteresis characteristic of MRD may cause the nonlinear behaviors. In this work, a two-degree-of-freedom (2-DOF) MR suspension system was established first, by employing the modified Bouc–Wen force–velocity (F–v) hysteretic model. The nonlinear dynamic response of the system was investigated under the external excitation of single-frequency harmonic and bandwidth-limited stochastic road surface. The largest Lyapunov exponent (LLE) was used to detect the chaotic area of the frequency and amplitude of harmonic excitation, and the bifurcation diagrams, time histories, phase portraits, and power spectrum density (PSD) diagrams were used to reveal the dynamic evolution process in detail. Moreover, the LLE and Kolmogorov entropy (K entropy) were used to identify whether the system response was random or chaotic under stochastic road surface. The results demonstrated that the complex dynamical behaviors occur under different external excitation conditions. The oscillating mechanism of alternating periodic oscillations, quasi-periodic oscillations, and chaotic oscillations was observed in detail. The chaotic regions revealed that chaotic motions may appear in conditions of mid-low frequency and large amplitude, as well as small amplitude and all frequency. The obtained parameter regions where the chaotic motions may appear are useful for design of structural parameters of the vibration isolation, and the optimization of control strategy for MR suspension system. (paper)

Linear viscoelastic properties of aging suspensions

NARCIS (Netherlands)

Purnomo, E.H.; Purnomo, E.H; van den Ende, Henricus T.M.; Mellema, J.; Mugele, Friedrich Gunther

2006-01-01

We have examined the linear viscoelastic behavior of poly-N-isopropylacrylamide (PNIPAM) microgel suspensions in order to obtain insight in the aging processes in these densely packed suspensions at various temperatures below the volume transition temperature. The system is found to display a strong

Development of the Nissan hydraulic active suspension. Nissan yuatsu active suspension no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Kawarasaki, y.; Fukunaga, Y.; Hasegawa, S.; Okuyama, Y.; Omura, I.; Takahashi, K.; Abe, S.; Tsuruta, E. (Nissan Motor Co. Ltd., Tokyo (Japan))

1989-12-25

A hydraulic active suspension system, Nissan original product, was developed and mass produced for the first time in the world. The system incorporates a sufficient power source, a high accuracy sensor and a high response device for continuous and intended vehicle control and at the same time delivers high levels of ride comfort and driving performance. The suspension system has four innovative features: skyhook damping, active roll and pitching control, a frequency-dependent damping mechanism, and active steering characteristics control. Under all road and operating conditions, the system actively suppresses vehicle attitude changes and unnecessary movement, and also gently absorbs inputs from the road. This epoch-making system provides a dramatic improvement in vehicle performance, and has been adopted in the Infiniti Q45 luxury sedan. 2 refs., 20 figs., 4 tabs.

Gravitational radiation from electromagnetic systems

International Nuclear Information System (INIS)

Nikishov, A.I.; Ritus, V.I.

1989-01-01

It is shown that the spectrum of gravitational radiation of a charge e with mass m, undergoing finite motion in an electromagnetic field, smoothly varying in the neighborhood of the orbit over a region of the order of the radius of curvature, differs in the ultrarelativistic limit from the spectrum of the charge's electromagnetic radiation. The difference consists of the frequency-independent coefficient 4πGm 2 Λ 2 /e 2 , where Λ is of the order of the Lorentz factor of the charge and depends on the direction of the wave vector and on the behavior of the field in the above-indicated region. For a plane-wave external field the gravitational and electromagnetic spectra are strictly proportional to each other for arbitrary velocities of the charge. Localization of the external forces near the orbit violates this proportionality of the spectra and weakens the gravitational radiation by an amount of the order of the square of the Lorentz factor

Calculation of electromagnetic force in electromagnetic forming process of metal sheet

International Nuclear Information System (INIS)

Xu Da; Liu Xuesong; Fang Kun; Fang Hongyuan

2010-01-01

Electromagnetic forming (EMF) is a forming process that relies on the inductive electromagnetic force to deform metallic workpiece at high speed. Calculation of the electromagnetic force is essential to understand the EMF process. However, accurate calculation requires complex numerical solution, in which the coupling between the electromagnetic process and the deformation of workpiece needs be considered. In this paper, an appropriate formula has been developed to calculate the electromagnetic force in metal work-piece in the sheet EMF process. The effects of the geometric size of coil, the material properties, and the parameters of discharge circuit on electromagnetic force are taken into consideration. Through the formula, the electromagnetic force at different time and in different positions of the workpiece can be predicted. The calculated electromagnetic force and magnetic field are in good agreement with the numerical and experimental results. The accurate prediction of the electromagnetic force provides an insight into the physical process of the EMF and a powerful tool to design optimum EMF systems.

Adaptive Neural-Sliding Mode Control of Active Suspension System for Camera Stabilization

Directory of Open Access Journals (Sweden)

Feng Zhao

2015-01-01

Full Text Available The camera always suffers from image instability on the moving vehicle due to the unintentional vibrations caused by road roughness. This paper presents a novel adaptive neural network based on sliding mode control strategy to stabilize the image captured area of the camera. The purpose is to suppress vertical displacement of sprung mass with the application of active suspension system. Since the active suspension system has nonlinear and time varying characteristics, adaptive neural network (ANN is proposed to make the controller robustness against systematic uncertainties, which release the model-based requirement of the sliding model control, and the weighting matrix is adjusted online according to Lyapunov function. The control system consists of two loops. The outer loop is a position controller designed with sliding mode strategy, while the PID controller in the inner loop is to track the desired force. The closed loop stability and asymptotic convergence performance can be guaranteed on the basis of the Lyapunov stability theory. Finally, the simulation results show that the employed controller effectively suppresses the vibration of the camera and enhances the stabilization of the entire camera, where different excitations are considered to validate the system performance.

Principles and techniques of radiation hardening. Volume 3. Electromagnetic pulse (EMP) and system generated EMP

International Nuclear Information System (INIS)

Rudie, N.J.

1976-01-01

The three-volume book is intended to serve as a review of the effects of thermonuclear explosion induced radiation (x-rays, gamma rays, and beta particles) and the resulting electromagnetic pulse (EMP). Volume 3 deals with the following topics: selected fundamentals of electromagnetic theory; EMP induced currents on antennas and cables; the EMP response of electronics; EMP hardening; EMP testing; injection currents; internal electromagnetic pulse (IEMP); replacement currents; and system generated electromagnetic pulse (SGEMP) hardening

41 CFR 105-74.670 - Suspension.

Science.gov (United States)

2010-07-01

... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Suspension. 105-74.670 Section 105-74.670 Public Contracts and Property Management Federal Property Management Regulations System...-GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 105-74.670 Suspension...

Solution or suspension - Does it matter for lipid based systems?

DEFF Research Database (Denmark)

Larsen, A T; Holm, R; Müllertz, A

2017-01-01

In this study, the potential of co-administering an aqueous suspension with a placebo lipid vehicle, i.e. chase dosing, was investigated in rats relative to the aqueous suspension alone or a solution of the drug in the lipid vehicle. The lipid investigated in the present study was Labrafil M2125CS...... and three evaluated poorly soluble model compounds, danazol, cinnarizine and halofantrine. For cinnarizine and danazol the oral bioavailability in rats after chase dosing or dosing the compound dissolved in Labrafil M21515CS was similar and significantly higher than for the aqueous suspension....... For halofantrine the chase dosed group had a tendency towards a low bioavailability relative to the Labrafil M2125CS solution, but still a significant higher bioavailability relative to the aqueous suspension. This could be due to factors such as a slower dissolution rate in the intestinal phase of halofantrine...

Sparse symmetric preconditioners for dense linear systems in electromagnetism

NARCIS (Netherlands)

Carpentieri, Bruno; Duff, Iain S.; Giraud, Luc; Monga Made, M. Magolu

2004-01-01

We consider symmetric preconditioning strategies for the iterative solution of dense complex symmetric non-Hermitian systems arising in computational electromagnetics. In particular, we report on the numerical behaviour of the classical incomplete Cholesky factorization as well as some of its recent

A remote monitoring system of environmental electromagnetic field in magnetic confinement fusion test facilities

International Nuclear Information System (INIS)

Tanaka, Masahiro; Uda, Tatsuhiko; Takami, Shigeyuki; Wang, Jianqing; Fujiwara, Osamu

2010-01-01

A remote, continuous environmental electromagnetic field monitoring system for use in magnetic confinement fusion test facilities is developed. Using this system, both the static magnetic field and the high frequency electromagnetic field could be measured. The required frequency range of the measurement system is from 25 to 100 MHz for the ICRF (Ion Cyclotron Range of Frequencies) heating system. The outputs from the measurement instruments are measured simultaneously by custom-built software using a laptop-type personal computer connected to a local area network. In this way, the electromagnetic field strength could be monitored from a control room located about 200 m from the fusion device building. Examples of measurement data from the vicinity of a high-frequency generator and amplifier and the leakage static magnetic field from a fusion test device are presented. (author)

Nonlinear Dynamics Analysis of the Semiactive Suspension System with Magneto-Rheological Damper

Directory of Open Access Journals (Sweden)

Hailong Zhang

2015-01-01

Full Text Available This paper examines dynamical behavior of a nonlinear oscillator which models a quarter-car forced by the road profile. The magneto-rheological (MR suspension system has been established, by employing the modified Bouc-Wen force-velocity (F-v model of magneto-rheological damper (MRD. The possibility of chaotic motions in MR suspension is discovered by employing the method of nonlinear stability analysis. With the bifurcation diagrams and corresponding Lyapunov exponent (LE spectrum diagrams detected through numerical calculation, we can observe the complex dynamical behaviors and oscillating mechanism of alternating periodic oscillations, quasiperiodic oscillations, and chaotic oscillations with different profiles of road excitation, as well as the dynamical evolutions to chaos through period-doubling bifurcations, saddle-node bifurcations, and reverse period-doubling bifurcations.

A Semiactive and Adaptive Hybrid Control System for a Tracked Vehicle Hydropneumatic Suspension Based on Disturbance Identification

Directory of Open Access Journals (Sweden)

Shousong Han

2017-01-01

Full Text Available The riding conditions for a high-speed tracked vehicle are quite complex. To enhance the adaptability of suspension systems to different riding conditions, a semiactive and self-adaptive hybrid control strategy based on disturbance velocity and frequency identification was proposed. A mathematical model of the semiactive, self-adaptive hybrid suspension control system, along with a performance evaluation function, was established. Based on a two-degree-of-freedom (DOF suspension system, the kinematic relations and frequency zero-crossing detection method were defined, and expressions for the disturbance velocity and disturbance frequency of the road were obtained. Optimal scheduling of the semiactive hybrid damping control gain (csky, cground, chybrid and self-adaptive control gain (cv under different disturbances were realized by exploiting the particle swarm multiobjective optimization algorithm. An experimental study using a carefully designed test rig was performed under a number of typical riding conditions of tracked vehicles, and the results showed that the proposed control strategy is capable of accurately recognizing different disturbances, shifting between control modes (semiactive/self-adaptive, and scheduling the damping control gain according to the disturbance identification outcomes; hence, the proposed strategy could achieve a good trade-off between ride comfort and ride safety and efficiently increase the overall performance of the suspension under various riding conditions.

Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles

OpenAIRE

Abid, Haider J.; Chen, Jie; Nassar, Ameen A.

2015-01-01

This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, l...

A transgenic plant cell-suspension system for expression of epitopes on chimeric Bamboo mosaic virus particles.

Science.gov (United States)

Muthamilselvan, Thangarasu; Lee, Chin-Wei; Cho, Yu-Hsin; Wu, Feng-Chao; Hu, Chung-Chi; Liang, Yu-Chuan; Lin, Na-Sheng; Hsu, Yau-Heiu

2016-01-01

We describe a novel strategy to produce vaccine antigens using a plant cell-suspension culture system in lieu of the conventional bacterial or animal cell-culture systems. We generated transgenic cell-suspension cultures from Nicotiana benthamiana leaves carrying wild-type or chimeric Bamboo mosaic virus (BaMV) expression constructs encoding the viral protein 1 (VP1) epitope of foot-and-mouth disease virus (FMDV). Antigens accumulated to high levels in BdT38 and BdT19 transgenic cell lines co-expressing silencing suppressor protein P38 or P19. BaMV chimeric virus particles (CVPs) were subsequently purified from the respective cell lines (1.5 and 2.1 mg CVPs/20 g fresh weight of suspended biomass, respectively), and the resulting CVPs displayed VP1 epitope on the surfaces. Guinea pigs vaccinated with purified CVPs produced humoral antibodies. This study represents an important advance in the large-scale production of immunopeptide vaccines in a cost-effective manner using a plant cell-suspension culture system. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

An approach for multi-objective optimization of vehicle suspension system

Science.gov (United States)

Koulocheris, D.; Papaioannou, G.; Christodoulou, D.

2017-10-01

In this paper, a half car model of with nonlinear suspension systems is selected in order to study the vertical vibrations and optimize its suspension system with respect to ride comfort and road holding. A road bump was used as road profile. At first, the optimization problem is solved with the use of Genetic Algorithms with respect to 6 optimization targets. Then the k - ɛ optimization method was implemented to locate one optimum solution. Furthermore, an alternative approach is presented in this work: the previous optimization targets are separated in main and supplementary ones, depending on their importance in the analysis. The supplementary targets are not crucial to the optimization but they could enhance the main objectives. Thus, the problem was solved again using Genetic Algorithms with respect to the 3 main targets of the optimization. Having obtained the Pareto set of solutions, the k - ɛ optimality method was implemented for the 3 main targets and the supplementary ones, evaluated by the simulation of the vehicle model. The results of both cases are presented and discussed in terms of convergence of the optimization and computational time. The optimum solutions acquired from both cases are compared based on performance metrics as well.

Research on magnetorheological damper suspension with permanent magnet and magnetic valve based on developed FOA-optimal control algorithm

Energy Technology Data Exchange (ETDEWEB)

Xiao, Ping; Gao, Hong [Anhui Polytechnic University, Wuhu (China); Niu, Limin [Anhui University of Technology, Maanshan (China)

2017-07-15

Due to the fail safe problem, it was difficult for the existing Magnetorheological damper (MD) to be widely applied in automotive suspensions. Therefore, permanent magnets and magnetic valves were introduced to existing MDs so that fail safe problem could be solved by the magnets and damping force could be adjusted easily by the magnetic valve. Thus, a new Magnetorheological damper with permanent magnet and magnetic valve (MDPMMV) was developed and MDPMMV suspension was studied. First of all, mechanical structure of existing magnetorheological damper applied in automobile suspensions was redesigned, comprising a permanent magnet and a magnetic valve. In addition, prediction model of damping force was built based on electromagnetics theory and Bingham model. Experimental research was onducted on the newly designed damper and goodness of fit between experiment results and simulated ones by models was high. On this basis, a quarter suspension model was built. Then, fruit Fly optimization algorithm (FOA)-optimal control algorithm suitable for automobile suspension was designed based on developing normal FOA. Finally, simulation experiments and bench tests with input surface of pulse road and B road were carried out and the results indicated that working erformance of MDPMMV suspension based on FOA-optimal control algorithm was good.

Active Control of Suspension Bridges

DEFF Research Database (Denmark)

Thoft-Christensen, Palle

In this paper some recent research on active control of very long suspension bridges, is presented. The presentation is based on research work at Aalborg University, Denmark. The active control system is based on movable flaps attached to the bridge girder. Wind load on bridges with or without...... flaps attached to the girder is briefly presented. A simple active control system is discussed. Results from wind tunnel experiments with a bridge section show that flaps can be used effectively to control bridge girder vibrations. Flutter conditions for suspension bridges with and without flaps...

Final Report: Model interacting particle systems for simulation and macroscopic description of particulate suspensions

Energy Technology Data Exchange (ETDEWEB)

Peter J. Mucha

2007-08-30

Suspensions of solid particles in liquids appear in numerous applications, from environmental settings like river silt, to industrial systems of solids transport and water treatment, and biological flows such as blood flow. Despite their importance, much remains unexplained about these complicated systems. Mucha's research aims to improve understanding of basic properties of suspensions through a program of simulating model interacting particle systems with critical evaluation of proposed continuum equations, in close collaboration with experimentalists. Natural to this approach, the original proposal centered around collaboration with studies already conducted in various experimental groups. However, as was detailed in the 2004 progress report, following the first year of this award, a number of the questions from the original proposal were necessarily redirected towards other specific goals because of changes in the research programs of the proposed experimental collaborators. Nevertheless, the modified project goals and the results that followed from those goals maintain close alignment with the main themes of the original proposal, improving efficient simulation and macroscopic modeling of sedimenting and colloidal suspensions. In particular, the main investigations covered under this award have included: (1) Sedimentation instabilities, including the sedimentation analogue of the Rayleigh-Taylor instability (for heavy, particle-laden fluid over lighter, clear fluid). (2) Ageing dynamics of colloidal suspensions at concentrations above the glass transition, using simplified interactions. (3) Stochastic reconstruction of velocity-field dependence for particle image velocimetry (PIV). (4) Stochastic modeling of the near-wall bias in 'nano-PIV'. (5) Distributed Lagrange multiplier simulation of the 'internal splash' of a particle falling through a stable stratified interface. (6) Fundamental study of velocity fluctuations in sedimentation

Analysis of Structural and Material Aspects of Selected Elements of a Hydropneumatic Suspension System in a Passenger Car

Directory of Open Access Journals (Sweden)

Konieczny Ł.

2016-03-01

Full Text Available The article addresses results of analyses of design solutions and materials commonly used in gas springs for hydropneumatic suspension systems. The authors have discussed main advantages resulting from application of such a design solution in passenger car suspension systems. Fundamental correlations defining the parameters characterising a gas spring with constant gas mass have been referred to. Also materials used in the manufacture of selected gas spring elements have been described

Amplitude control of the track-induced self-excited vibration for a maglev system.

Science.gov (United States)

Zhou, Danfeng; Li, Jie; Zhang, Kun

2014-09-01

The Electromagnet Suspension (EMS) maglev train uses controlled electromagnetic forces to achieve suspension, and self-excited vibration may occur due to the flexibility of the track. In this article, the harmonic balance method is applied to investigate the amplitude of the self-excited vibration, and it is found that the amplitude of the vibration depends on the voltage of the power supplier. Based on this observation, a vibration amplitude control method, which controls the amplitude of the vibration by adjusting the voltage of the power supplier, is proposed to attenuate the vibration. A PI controller is designed to control the amplitude of the vibration at a given level. The effectiveness of this method shows a good prospect for its application to commercial maglev systems. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Nonlinear Coupling Characteristics Analysis of Integrated System of Electromagnetic Brake and Frictional Brake of Car

Directory of Open Access Journals (Sweden)

Ren He

2015-01-01

Full Text Available Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and conducts the contrastive analysis on the dynamic characteristics based on this mathematical model. Meanwhile, the accuracy of the nonlinear coupling mathematical model proposed above is verified on the hardware in the loop simulation platform, and nonlinear coupling characteristics of the integrated system are also analyzed through experiments.

Simulation of disturbance rejection control of half-car active suspension system using active disturbance rejection control with decoupling transformation

Science.gov (United States)

Hasbullah, Faried; Faris, Waleed F.

2017-12-01

In recent years, Active Disturbance Rejection Control (ADRC) has become a popular control alternative due to its easy applicability and robustness to varying processes. In this article, ADRC with input decoupling transformation (ADRC-IDT) is proposed to improve ride comfort of a vehicle with an active suspension system using half-car model. The ride performance of the ADRC-IDT is evaluated and compared with decentralized ADRC control as well as the passive system. Simulation results show that both ADRC and ADRC-IDT manage to appreciably reduce body accelerations and able to cope well with varying conditions typically encountered in an active suspension system. Also, it is sufficient to control only the body motions with both active controllers to improve ride comfort while maintaining good road holding and small suspension working space.

Differential Evolution-Based PID Control of Nonlinear Full-Car Electrohydraulic Suspensions

Directory of Open Access Journals (Sweden)

Jimoh O. Pedro

2013-01-01

Full Text Available This paper presents a differential-evolution- (DE- optimized, independent multiloop proportional-integral-derivative (PID controller design for full-car nonlinear, electrohydraulic suspension systems. The multiloop PID control stabilises the actuator via force feedback and also improves the system performance. Controller gains are computed using manual tuning and through DE optimization to minimise a performance index, which addresses suspension travel, road holding, vehicle handling, ride comfort, and power consumption constraints. Simulation results showed superior performance of the DE-optimized PID-controlled active vehicle suspension system (AVSS over the manually tuned PID-controlled AVSS and the passive vehicle suspension system (PVSS.

Coherent scattering of electromagnetic radiation by a polarized particle system

International Nuclear Information System (INIS)

Agre, M.Ya.; Rapoport, L.P.

1996-01-01

The paper deals with the development of the theory of coherent scattering of electromagnetic waves by a polarized atom or molecular system. Peculiarities of the angular distribution and polarization peculiarities of scattered radiation are discussed

A broadband electromagnetic UT system

International Nuclear Information System (INIS)

Repplinger, W.; Salzburger, H.J.

1985-01-01

An ultrasonic testing system based on contactless electromagnetic acoustic (E.M.A.) transduction has been developed by which broadband ultrasonic pulses are excited. This system overcomes disadvantages of usual E.M.A. transducers with meanderlike coil configuration, namely the excitation of narrowband pulses and the symmetrical radiation pattern. By dividing up a meanderlike coil into single elements and a time-delayed firing of the elements, whereby the time delay is given by the distance of the elements and the phase velocity of the wave propagating along the surface, the ultrasonic pulse radiated in one preferred direction becomes broadband by constructive interference. The signals radiated in the opposite direction do no more interfere. Its amplitude is smaller than that of the other direction, so that the transducer becomes uni-directional. This technique can be applied for the excitation of all dispersionless waves (bulk waves and guided waves)

Electromagnetic radiation and nonlinear energy flow in an electron beam-plasma system

Science.gov (United States)

Whelan, D. A.; Stenzel, R. L.

1985-01-01

It is shown that the unstable electron-plasma waves of a beam-plasma system can generate electromagnetic radiation in a uniform plasma. The generation mechanism is a scattering of the unstable electron plasma waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local plasma frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable plasma wave region. The frequency spectrum shows negligible intensity near the second harmonic of the plasma frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local plasma frequency and observed downstream where the wave frequency is near the harmonic of the plasma frequency.

Analysis of Driving Safety Criteria Based on National Regulations for the Suspension Systems of NGVs

Directory of Open Access Journals (Sweden)

Ronald Mauricio Martinod

2015-01-01

Full Text Available The work analyses the technical evaluation process of the suspension system for vehicles that have been adapted to natural-gas-fuelled engines from power light-duty gasoline, and diesel vehicles; this evaluation is done through a mechanical review established by national regulations. The development of this analysis is focused on establishing the relationship between the natural-gas-fuelled equipment and the dynamic effect caused by the extra-weight, according to two measuring criteria that determine the safety and driving comfort, these are: (i tire-road adhesion index; and (ii tire excitation phase angle. The paper also proposes new elements that can be added to the current national regulations and that are currently applied to assess the suspension of natural gas vehicles, recorded using a test standard benchmark for the evaluation of the suspension.

Analysis of the fields emitted by mobile communication systems in terms of electromagnetic security

International Nuclear Information System (INIS)

Kerimov, E.A.; Abdullayeva, T.M.; Bayramova, Sh.A.; Mardakhayev, A.V.; Khidirov, A.Sh.

2009-01-01

The main technical characteristics of digital communication systems of cellular bond are analyzed in this paper.The peculiarities of the electromagnetic fields near the antenna of digital communication systems of cellular bond with frequency, time and code interleaving of subscriber channels.It is shown that it is necessary to pay attention to relative broadbandness of digital signal spectrum on antenna radiation characteristics at carrying out of works on electromagnetic monitoring

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers

Energy Technology Data Exchange (ETDEWEB)

Luo, Xiongbiao, E-mail: xiongbiao.luo@gmail.com [Robarts Research Institute, Western University, London, Ontario N6A 5K8 (Canada)

2014-06-15

Purpose: Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. Methods: The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model was designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. Results: The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0–10 min{sup −1}. The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. Conclusions: An

A bronchoscopic navigation system using bronchoscope center calibration for accurate registration of electromagnetic tracker and CT volume without markers

International Nuclear Information System (INIS)

Luo, Xiongbiao

2014-01-01

Purpose: Various bronchoscopic navigation systems are developed for diagnosis, staging, and treatment of lung and bronchus cancers. To construct electromagnetically navigated bronchoscopy systems, registration of preoperative images and an electromagnetic tracker must be performed. This paper proposes a new marker-free registration method, which uses the centerlines of the bronchial tree and the center of a bronchoscope tip where an electromagnetic sensor is attached, to align preoperative images and electromagnetic tracker systems. Methods: The chest computed tomography (CT) volume (preoperative images) was segmented to extract the bronchial centerlines. An electromagnetic sensor was fixed at the bronchoscope tip surface. A model was designed and printed using a 3D printer to calibrate the relationship between the fixed sensor and the bronchoscope tip center. For each sensor measurement that includes sensor position and orientation information, its corresponding bronchoscope tip center position was calculated. By minimizing the distance between each bronchoscope tip center position and the bronchial centerlines, the spatial alignment of the electromagnetic tracker system and the CT volume was determined. After obtaining the spatial alignment, an electromagnetic navigation bronchoscopy system was established to real-timely track or locate a bronchoscope inside the bronchial tree during bronchoscopic examinations. Results: The electromagnetic navigation bronchoscopy system was validated on a dynamic bronchial phantom that can simulate respiratory motion with a breath rate range of 0–10 min −1 . The fiducial and target registration errors of this navigation system were evaluated. The average fiducial registration error was reduced from 8.7 to 6.6 mm. The average target registration error, which indicates all tracked or navigated bronchoscope position accuracy, was much reduced from 6.8 to 4.5 mm compared to previous registration methods. Conclusions: An

Pair-correlations in swimmer suspensions

Science.gov (United States)

Nambiar, Sankalp; Subramanian, Ganesh

2017-11-01

Suspensions of rear-actuated swimming microorganisms, such as E.coli, exhibit several interesting phenomena including spontaneous pattern formation above a critical concentration, novel rheological properties, shear-induced concentration banding etc. Explanations based on mean-field theory are only qualitative, since interactions between swimmers are important for typical experimental concentrations. We analytically characterize the hydrodynamic pair-interactions in a quiescent suspension of slender straight swimmers. The pair-correlation, calculated at leading order by integrating the swimmer velocity disturbances along straight trajectories, decays as 1/r2 for r >> L (L being the swimmer size). This allows us to characterize both polar and nematic correlations in an interacting swimmer suspension. In the absence of correlations, the velocity covariance asymptotes from a constant for r > L, the latter being characteristic of a suspension of non-interacting point force-dipoles. On including correlations, the slow decay of the pair-orientation correlation leads to an additional contribution to the velocity covariance that diverges logarithmically with system size.

Optimization of Automotive Suspension System by Design of Experiments: A Nonderivative Method

Directory of Open Access Journals (Sweden)

Anirban C. Mitra

2016-01-01

Full Text Available A lot of health issues like low back pain, digestive disorders, and musculoskeletal disorders are caused as a result of the whole body vibrations induced by automobiles. This paper is concerned with the enhancement and optimization of suspension performance by using factorial methods of Design of Experiments, a nonderivative method. It focuses on the optimization of ride comfort and determining the parameters which affect the suspension behavior significantly as per the guidelines stated in ISO 2631-1:1997 standards. A quarter car test rig integrated with a LabVIEW based data acquisition system was developed to understand the real time behavior of a vehicle. In the pilot experiment, only three primary suspension parameters, that is, spring-stiffness, damping, and sprung mass, were considered and the full factorial method was implemented for the purpose of optimization. But the regression analysis of the data obtained rendered a very low goodness of fit which indicated that other parameters are likely to influence the response. Subsequently, steering geometry angles, camber and toe and tire pressure, were included in the design. Fractional factorial method with six factors was implemented to optimize ride comfort. The resultant optimum combination was then verified on the test rig with high correlation.

A 16 MJ compact pulsed power system for electromagnetic launch

Science.gov (United States)

Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

2015-07-01

This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.

Mirror suspension system for the TAMA SAS

International Nuclear Information System (INIS)

Takamori, Akiteru; Ando, Masaki; Bertolini, Alessandro; Cella, Giancarlo; DeSalvo, Riccardo; Fukushima, Mitsuhiro; Iida, Yukiyoshi; Jacquier, Florian; Kawamura, Seiji; Marka, Szabolcs; Nishi, Yuhiko; Numata, Kenji; Sannibale, Virginio; Somiya, Kentaro; Takahashi, Ryutaro; Tariq, Hareem; Tsubono, Kimio; Ugas, Jose; Viboud, Nicolas; Yamamoto, Hiroaki; Yoda, Tatsuo; Wang Chenyang

2002-01-01

Several R and D programmes are ongoing to develop the next generation of interferometric gravitational wave detectors providing the superior sensitivity desired for refined astronomical observations. In order to obtain a wide observation band at low frequencies, the optics need to be isolated from the seismic noise. The TAMA SAS (seismic attenuation system) has been developed within an international collaboration between TAMA, LIGO, and some European institutes, with the main objective of achieving sufficient low-frequency seismic attenuation (-180 dB at 10 HZ). The system suppresses seismic noise well below the other noise levels starting at very low frequencies above 10 Hz. It also includes an active inertial damping system to decrease the residual motion of the optics enough to allow a stable operation of the interferometer. The TAMA SAS also comprises a sophisticated mirror suspension subsystem (SUS). The SUS provides support for the optics and vibration isolation complementing the SAS performance. The SUS is equipped with a totally passive magnetic damper to suppress internal resonances without degrading the thermal noise performance. In this paper we discuss the SUS details and present prototype results

Electromagnetic form factors of composite systems

International Nuclear Information System (INIS)

Nowak, E.J.

1978-01-01

Electromagnetic form factors are examined for a spin-zero, two-body composite system with emphasis on the case of small momentum transfer and/or deep (relativistic) binding. Perturbation theory calculations are first performed using spin-zero and then spin-one-half constituents. A dispersion representation of the bound-state vertex function is conjectured first for scalar and then for fermion constituents. Then a relativistic effective range approximation (RERA) is developed for each case and applied to the calculation of the electromagnetic form factor. The approach is applied to the study of the charge radii of the K 0 and K + mesons. The K/sub l3/ form factor is calculated in the fermion constituent RERA model, and restrictions are imposed on the model parameters from available experimental data. With these restrictions the limits 0.24fm less than or equal to √[abs. value ( 2 >/sub K 0 /)] less than or equal to = 0.36fm and 0.66fm less than or equal to = √( 2 >/sub K + /) less than or equal to 0.79fm are obtained for the kaon charge radii, and -.22 less than or equal to xi less than or equal to -.13 is found for the ratio of the neutral to charged kaon charge radius squared

Study of electromagnetic interference on quench detecting system of HTS current leads for EAST

International Nuclear Information System (INIS)

Hu, Yanlan; Li, Jiangang; Ji, Zhenshan; Zhu, C.M.; Zhen, L.G.; Xiao, Y.Z.

2013-01-01

Highlights: • EAST HTS superconducting magnet system shall be operating in a very noisy environment. • Voltage taps will have a lot of inductive voltage induced on them which makes quench detection very difficult. • The noise comes from the coupling between rapid pulsed poloidal coils, and radiation coupling interference associated with EAST heating systems;. • A series of related electromagnetic compatibility simulation tests have been carried out. • Electromagnetic noises are well restrained by choosing proper anti-interference means. -- Abstract: High temperature superconducting (HTS) material B-2223/Ag-Au has been used for EAST poloidal field (PF) coil current leads for reducing construction and operation cost of cryogenic system. The quench propagation velocity of HTS superconducting material is several orders of magnitude lower than that of normal low temperature current leads. It is difficult to detect weak signal of quench which is easily influenced by strong electromagnetic interference (EMI). In this paper, the sources of EMI from quench detecting system of high temperature current leads have been introduced. And we have chosen reasonable methods for good transformation and protection on the basis of electromagnetic compatibility simulation diagnosis experiments. Recent experimental results showed that the restraint of EMI has been achieved and has met the requirements of experiment

Absorption of electromagnetic field energy by superfluid system of atoms with electric dipole moment

International Nuclear Information System (INIS)

Poluektov, Yu.M.

2014-01-01

The modified Gross-Pitaevskii equation which takes into account relaxation and interaction with alternating electromagnetic field is used to consider the absorption of electromagnetic field energy by a superfluid system on the assumption that the atoms has intrinsic dipole moment. It is shown that the absorption may be of a resonant behavior only if the dispersion curves of the electromagnetic wave and the excitations of the superfluid system intersect. It is remarkable that such a situation is possible if the superfluid system has a branch of excitations with the energy gap at low momenta. The experiments on absorption of microwaves in superfluid helium are interpreted as evidence of existence of such gap excitations. A possible modification of the excitation spectrum of superfluid helium in the presence of excitation branch with energy gap is dis-cussed qualitatively

Electromagnetic Systems Effects Database (EMSED). AERO 90, Phase II User's Manual

National Research Council Canada - National Science Library

Sawires, Kalim

1998-01-01

The Electromagnetic Systems Effects Database (EMSED), also called AIRBASE, is a training guide for users not familiar with the AIRBASE database and its operating platform, the Macintosh computer (Mac...

Effect of Electromagnetic Fields on Transfer Processes in Heterogeneous Systems

Czech Academy of Sciences Publication Activity Database

Levdansky, V.V.; Kim, H. Y.; Kim, H. C.; Smolík, Jiří; Moravec, Pavel

2001-01-01

Roč. 44, č. 5 (2001), s. 1065-1071 ISSN 0017-9310 Institutional research plan: CEZ:AV0Z4072921 Keywords : electromagnetic field * transfer processes * heterogeneous system Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.240, year: 2001

Electrochemical analysis in a liposome suspension using lapachol as a hydrophobic electro active species.

Science.gov (United States)

Okumura, Noriko; Wakamatsu, Shiori; Uno, Bunji

2014-01-01

This study demonstrated that the electro-chemical analysis of hydrophobic quinones can be performed in liposome suspension systems. We prepared and analyzed liposome suspensions containing lapachol, which is a quinone-based anti-tumor activity compound. In this suspension system, a simple one redox couple of lapachol is observed. These results are quite different from those obtained in organic solvents. In addition, the pH dependence of redox behaviors of lapachol could be observed in multilamellar vesicle (MLV) suspension system. This MLV suspension system method may approximate the electrochemical behavior of hydrophobic compounds in aqueous conditions. A benefit of this liposome suspension system for electrochemical analysis is that it enables to observe water-insoluble compounds without using organic solvents.

Slow flow solutions and chaos control in an electromagnetic seismometer system

International Nuclear Information System (INIS)

Lazzouni, S.A.; Siewe Siewe, M.; Moukam Kakmeni, F.M.; Bowong, S.

2005-05-01

We study in this paper the dynamics and chaos control of a nonlinear electromagnetic seismometer system consisting of an extended Duffing electrical oscillator magnetically coupled with a natural Duffing mechanical oscillator. The singular perturbation method is used to find slow solutions. Some bifurcation structures and the variation of the corresponding Lyapunov exponent are obtained. Transitions from a regular behavior to chaotic orbits are seen to occur for large amplitudes of the external excitation. We also examine the application of a simple adaptive damping feedback controller to eliminate the chaotic behavior in a controlled extended Duffing system. The main idea is to regulate the chaotic motion of the electromagnetic seismometer system around less complex attractors, such as equilibrium points and periodic orbits. The effectiveness and efficiency of the proposed feedback control strategy is illustrated by means of numerical simulations. (author)

Electromagnetic compatibility (EMC) design guidelines for I and C systems for nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Hwang, In Koo; Lee, Dong Young; Cha, Kyung Ho; Park, Joo Hyun; Lee, Ki Young [Korea Atomic Energy Research Institute, Taejeon (Korea)

2002-02-01

This report describes the research results on Electromagnetic Compatibility technologies for I and C(Instrumentation and Control) systems for nuclear power plants. As the nuclear industries are adopting the digital equipment rather than the conventional analog type equipment for safety I and C systems as well as non-safety systems of nuclear power plants(NPPs), it is necessary to secure compatibility against EMI(electromagnetic interference) for the digital safety I and C systems. EMI qualification, identified as a regulatory compliance item by US NRC and Korean regulatory body, should be performed in accordance with appropriate standards, because the electromagnetic environment is regarded as one of the environmental factors possible to affect the safety functions. As a technical guide on this EMI issue, this report includes description of code and standards scheme, EMI qualification methods, noise reduction strategies, and survey on noise levels in nuclear power plants. 29 refs., 72 figs., 5 tabs. (Author)

On the Benefits of Semi-Active Suspensions with Inerters

Directory of Open Access Journals (Sweden)

Xin-Jie Zhang

2012-01-01

Full Text Available Inerters have become a hot topic in recent years especially in vehicle, train, building suspension systems, etc. Eight different layouts of suspensions were analyzed with a quarter-car model in this paper. Dimensionless root mean square (RMS responses of the sprung mass vertical acceleration, the suspension travel, and the tire deflection are derived which were used to evaluate the performance of the quarter-car model. The behaviour of semi-active suspensions with inerters using Groundhook, Skyhook, and Hybrid control has been evaluated and compared to the performance of passive suspensions with inerters. Sensitivity analysis was applied to the development of a high performance semi-active suspension with an inerter. Numerical simulations indicate that a semi-active suspension with an inerter has much better performance than the passive suspension with an inerter, especially with the Hybrid control method, which has the best compromise between comfort and road holding quality.

Torsional asymmetry in suspension bridge systems

Czech Academy of Sciences Publication Activity Database

Malík, Josef

2015-01-01

Roč. 60, č. 6 (2015), s. 677-701 ISSN 0862-7940 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : suspension bridge * Hamilton principle * vertical and torsional oscillation * uniqueness * existence Subject RIV: BA - General Mathematics Impact factor: 0.507, year: 2015 http://link.springer.com/article/10.1007%2Fs10492-015-0117-3

Comparative analysis of the operation efficiency of the continuous and relay control systems of a multi-axle wheeled vehicle suspension

Science.gov (United States)

Zhileykin, M. M.; Kotiev, G. O.; Nagatsev, M. V.

2018-02-01

In order to improve the efficiency of the multi-axle wheeled vehicles (MWV) automotive engineers are increasing their cruising speed. One of the promising ways to improve ride comfort of the MWV is the development of the dynamic active suspension systems and control laws for such systems. Here, by the dynamic control systems we mean the systems operating in real time mode and using current (instantaneous) values of the state variables. The aim of the work is to develop the MWV suspension optimal control laws that would reduce vibrations on the driver’s seat at kinematic excitation. The authors have developed the optimal control laws for damping the oscillations of the MWV body. The developed laws allow reduction of the vibrations on the driver’s seat and increase in the maximum speed of the vehicle. The laws are characterized in that they allow generating the control inputs in real time mode. The authors have demonstrated the efficiency of the proposed control laws by means of mathematical simulation of the MWV driving over unpaved road with kinematic excitation. The proposed optimal control laws can be used in the MWV suspension control systems with magnetorheological shock absorbers or controlled hydropneumatic springs. Further evolution of the research line can be the development of the energy-efficient MWV suspension control systems with continuous control input on the vehicle body.

Electromagnetic Compatibility Design of the Computer Circuits

Science.gov (United States)

Zitai, Hong

2018-02-01

Computers and the Internet have gradually penetrated into every aspect of people’s daily work. But with the improvement of electronic equipment as well as electrical system, the electromagnetic environment becomes much more complex. Electromagnetic interference has become an important factor to hinder the normal operation of electronic equipment. In order to analyse the computer circuit compatible with the electromagnetic compatibility, this paper starts from the computer electromagnetic and the conception of electromagnetic compatibility. And then, through the analysis of the main circuit and system of computer electromagnetic compatibility problems, we can design the computer circuits in term of electromagnetic compatibility. Finally, the basic contents and methods of EMC test are expounded in order to ensure the electromagnetic compatibility of equipment.

Hysteresis-induced bifurcation and chaos in a magneto-rheological suspension system under external excitation

Science.gov (United States)

Hailong, Zhang; Enrong, Wang; Fuhong, Min; Ning, Zhang

2016-03-01

The magneto-rheological damper (MRD) is a promising device used in vehicle semi-active suspension systems, for its continuous adjustable damping output. However, the innate nonlinear hysteresis characteristic of MRD may cause the nonlinear behaviors. In this work, a two-degree-of-freedom (2-DOF) MR suspension system was established first, by employing the modified Bouc-Wen force-velocity (F-v) hysteretic model. The nonlinear dynamic response of the system was investigated under the external excitation of single-frequency harmonic and bandwidth-limited stochastic road surface. The largest Lyapunov exponent (LLE) was used to detect the chaotic area of the frequency and amplitude of harmonic excitation, and the bifurcation diagrams, time histories, phase portraits, and power spectrum density (PSD) diagrams were used to reveal the dynamic evolution process in detail. Moreover, the LLE and Kolmogorov entropy (K entropy) were used to identify whether the system response was random or chaotic under stochastic road surface. The results demonstrated that the complex dynamical behaviors occur under different external excitation conditions. The oscillating mechanism of alternating periodic oscillations, quasi-periodic oscillations, and chaotic oscillations was observed in detail. The chaotic regions revealed that chaotic motions may appear in conditions of mid-low frequency and large amplitude, as well as small amplitude and all frequency. The obtained parameter regions where the chaotic motions may appear are useful for design of structural parameters of the vibration isolation, and the optimization of control strategy for MR suspension system. Projects supported by the National Natural Science Foundation of China (Grant Nos. 51475246, 51277098, and 51075215), the Research Innovation Program for College Graduates of Jiangsu Province China (Grant No. KYLX15 0725), and the Natural Science Foundation of Jiangsu Province of China (Grant No. BK20131402).

Dynamics and Control of a Chaotic Electromagnetic System

OpenAIRE

Shun-Chang Chang

2012-01-01

In this paper, different nonlinear dynamics analysis techniques are employed to unveil the rich nonlinear phenomena of the electromagnetic system. In particular, bifurcation diagrams, time responses, phase portraits, Poincare maps, power spectrum analysis, and the construction of basins of attraction are all powerful and effective tools for nonlinear dynamics problems. We also employ the method of Lyapunov exponents to show the occurrence of chaotic motion and to verify those numerical simula...

Compact vibration isolation and suspension for Australian International Gravitational Observatory: Local control system

Science.gov (United States)

Dumas, Jean-Charles; Barriga, Pablo; Zhao, Chunnong; Ju, Li; Blair, David G.

2009-11-01

High performance vibration isolators are required for ground based gravitational wave detectors. To attain very high performance at low frequencies we have developed multistage isolators for the proposed Australian International Gravitational Observatory detector in Australia. New concepts in vibration isolation including self-damping, Euler springs, LaCoste springs, Roberts linkages, and double preisolation require novel sensors and actuators. Double preisolation enables internal feedback to be used to suppress low frequency seismic noise. Multidegree of freedom control systems are required to attain high performance. Here we describe the control components and control systems used to control all degrees of freedom. Feedback forces are injected at the preisolation stages and at the penultimate suspension stage. There is no direct actuation on test masses. A digital local control system hosted on a digital signal processor maintains alignment and position, corrects drifts, and damps the low frequency linear and torsional modes without exciting the very high Q-factor test mass suspension. The control system maintains an optical cavity locked to a laser with a high duty cycle even in the absence of an autoalignment system. An accompanying paper presents the mechanics of the system, and the optical cavity used to determine isolation performance. A feedback method is presented, which is expected to improve the residual motion at 1 Hz by more than one order of magnitude.

Compact vibration isolation and suspension for Australian International Gravitational Observatory: local control system.

Science.gov (United States)

Dumas, Jean-Charles; Barriga, Pablo; Zhao, Chunnong; Ju, Li; Blair, David G

2009-11-01

High performance vibration isolators are required for ground based gravitational wave detectors. To attain very high performance at low frequencies we have developed multistage isolators for the proposed Australian International Gravitational Observatory detector in Australia. New concepts in vibration isolation including self-damping, Euler springs, LaCoste springs, Roberts linkages, and double preisolation require novel sensors and actuators. Double preisolation enables internal feedback to be used to suppress low frequency seismic noise. Multidegree of freedom control systems are required to attain high performance. Here we describe the control components and control systems used to control all degrees of freedom. Feedback forces are injected at the preisolation stages and at the penultimate suspension stage. There is no direct actuation on test masses. A digital local control system hosted on a digital signal processor maintains alignment and position, corrects drifts, and damps the low frequency linear and torsional modes without exciting the very high Q-factor test mass suspension. The control system maintains an optical cavity locked to a laser with a high duty cycle even in the absence of an autoalignment system. An accompanying paper presents the mechanics of the system, and the optical cavity used to determine isolation performance. A feedback method is presented, which is expected to improve the residual motion at 1 Hz by more than one order of magnitude.

Metamaterial inspired electromagnetic applications role of intelligent systems

CERN Document Server

2017-01-01

This book focuses on the role of soft-computing-based electromagnetic computational engines in design and optimization of a wide range of electromagnetic applications. In addition to the theoretical background of metamaterials and soft-computing techniques, the book discusses novel electromagnetic applications such as tensor analysis for invisibility cloaking, metamaterial structures for cloaking applications, broadband radar absorbers, and antennas. The book will prove to be a valuable resource for academics and professionals, as well as military researchers working in the area of metamaterials.

Observation of electromagnetically induced Talbot effect in an atomic system

Science.gov (United States)

Zhang, Zhaoyang; Liu, Xing; Zhang, Dan; Sheng, Jiteng; Zhang, Yiqi; Zhang, Yanpeng; Xiao, Min

2018-01-01

The electromagnetically induced Talbot effect (EITE) resulting from the repeated self-reconstruction of a spatially intensity-modulated probe field is experimentally demonstrated in a three-level atomic configuration. The probe beam is launched into an optically induced lattice (established by the interference of two coupling fields) inside a rubidium vapor cell and is diffracted by the electromagnetically induced grating that was formed. The diffraction pattern repeats itself at the planes of integer multiple Talbot lengths. In addition, a fractional EITE is also investigated. The experimental observations agree well with the theoretical predictions. This investigation may potentially pave the way for studying the nonlinear and quantum dynamical features that have been predicted for established periodic optical systems.

Lagrange formalism for a system of several fluids interacting electromagnetically

International Nuclear Information System (INIS)

Vuillemin, M.

1964-01-01

After giving the Lagrange expression for a conducting fluid in an external electromagnetic field, the author shows that a Lagrange expression exists for describing the evolution of a system of interacting fluids obtained by adding the Lagrange expression of each fluid.to that of the electromagnetic field. By variation are obtained the fluid movement equation coupled to the Maxwell equations. It is shown that the study of small movements around a stationary state can be deduced from the Lagrange equation expanded to the second power order of the perturbation. It is then possible to deduce the normal mode equations and the study the stability by examining the modes which are marginally stable. (author) [fr

Modeling of MEMS piezoelectric energy harvesters using electromagnetic and power system theories

International Nuclear Information System (INIS)

Ahmad, Mahmoud Al; Alshareef, H N; Elshurafa, Amro M; Salama, Khaled N

2011-01-01

This work proposes a novel methodology for estimating the power output of piezoelectric generators. An analytical model that estimates for the first time the loss ratio and output power of piezoelectric generators based on the direct mechanical-to-electrical analogy, electromagnetic theory, and power system theory is developed. The mechanical-to-electrical analogy and power system theory allow the derivation of an equivalent input impedance expression for the network, whereas electromagnetic transmission line theory allows deduction of the equivalent electromechanical loss of the piezoelectric generator. By knowing the mechanical input power and the loss of the network, calculation of the output power of the piezoelectric device becomes a straightforward procedure. Experimental results based on published data are also presented to validate the analytical solution. In order to fully benefit from the well-established electromagnetic transmission line and electric circuit theories, further analyses on the resonant frequency, bandwidth, and sensitivity are presented. Compared to the conventional modeling methods currently being adopted in the literature, the proposed method provides significant additional information that is crucial for enhanced device operation and quick performance optimization

Electromagnetic fields in small systems from a multiphase transport model

Science.gov (United States)

Zhao, Xin-Li; Ma, Yu-Gang; Ma, Guo-Liang

2018-02-01

We calculate the electromagnetic fields generated in small systems by using a multiphase transport (AMPT) model. Compared to A +A collisions, we find that the absolute electric and magnetic fields are not small in p +Au and d +Au collisions at energies available at the BNL Relativistic Heavy Ion Collider and in p +Pb collisions at energies available at the CERN Large Hadron Collider. We study the centrality dependencies and the spatial distributions of electromagnetic fields. We further investigate the azimuthal fluctuations of the magnetic field and its correlation with the fluctuating geometry using event-by-event simulations. We find that the azimuthal correlation 〈" close="〉cos(ϕα+ϕβ-2 ΨRP)〉">cos2 (ΨB-Ψ2) between the magnetic field direction and the second-harmonic participant plane is almost zero in small systems with high multiplicities, but not in those with low multiplicities. This indicates that the charge azimuthal correlation is not a valid probe to study the chiral magnetic effect (CME) in small systems with high multiplicities. However, we suggest searching for possible CME effects in small systems with low multiplicities.

Determination of Weight Suspension Rigidity in the Transport-Erector Aggregates

Directory of Open Access Journals (Sweden)

V. A. Zverev

2016-01-01

Full Text Available The aim is to determine weight suspension rigidity in aggregates designed to perform technological transport-erector operations at the miscellaneous launch complexes.We consider the weight suspension comprising the following distinctive structural components: the executive weight-lowering mechanism, polyspast mechanism, rope, traverse, and rods. A created structural dynamic model of suspension allowed us to define weight suspension rigidity. Within the framework of design analysis of a dynamic model we determined the rigidity of its structural units, i.e. traverse, rope, and polyspast.Known analytical relationships were used to calculate the rope rigidity. To determine rigidity of polyspast and traverse have been created special models based on the finite element method. For each model deformation in the specific points under the test load have been defined. Data obtained were used to determine trigidity of traverses and polyspast, and also rigidity of suspension in total. The rigidity models of polispast mechanism and traverse have been developed and calculated using the software complex "Zenit-95".As the research results, the paper presents a dynamic model of the weight suspension of the transport-erector aggregate, the finite element models of the polispast mechanism and traverse, an algorithm for determining the weight suspension rigidity and relevant analytical relationships.Independent calculation of weight suspension rigidity enables us to simplify further dynamic calculation of the aggregate-weight system because it allows attaining a simpler model of the aggregate-weight system that uses the weight suspension model as an element of equivalent rigidity. Despite this simplification the model allows us to determine correctly weight movement parameters and overloads in the aggregate-weight system in the process of technical operations.

Electromagnetic Signal Feedback Control for Proximity Detection Systems

Science.gov (United States)

Smith, Adam K.

Coal is the most abundant fossil fuel in the United States and remains an essential source of energy. While more than half of coal production comes from surface mining, nearly twice as many workers are employed by underground operations. One of the key pieces of equipment used in underground coal mining is the continuous mining machine. These large and powerful machines are operated in confined spaces by remote control. Since 1984, 40 mine workers in the U. S. have been killed when struck or pinned by a continuous mining machine. It is estimated that a majority of these accidents could have been prevented with the application of proximity detection systems. While proximity detection systems can significantly increase safety around a continuous mining machine, there are some system limitations. Commercially available proximity warning systems for continuous mining machines use magnetic field generators to detect workers and establish safe work areas around the machines. Several environmental factors, however, can influence and distort the magnetic fields. To minimize these effects, a control system has been developed using electromagnetic field strength and generator current to stabilize and control field drift induced by internal and external environmental factors. A laboratory test set-up was built using a ferrite-core magnetic field generator to produce a stable magnetic field. Previous work based on a field-invariant magnetic flux density model, which generically describes the electromagnetic field, is expanded upon. The analytically established transferable shell-based flux density distribution model is used to experimentally validate the control system. By controlling the current input to the ferrite-core generator, a more reliable and consistent magnetic field is produced. Implementation of this technology will improve accuracy and performance of existing commercial proximity detection systems. These research results will help reduce the risk of traumatic

Electromagnetic ultrasonic guided waves

CERN Document Server

Huang, Songling; Li, Weibin; Wang, Qing

2016-01-01

This book introduces the fundamental theory of electromagnetic ultrasonic guided waves, together with its applications. It includes the dispersion characteristics and matching theory of guided waves; the mechanism of production and theoretical model of electromagnetic ultrasonic guided waves; the effect mechanism between guided waves and defects; the simulation method for the entire process of electromagnetic ultrasonic guided wave propagation; electromagnetic ultrasonic thickness measurement; pipeline axial guided wave defect detection; and electromagnetic ultrasonic guided wave detection of gas pipeline cracks. This theory and findings on applications draw on the author’s intensive research over the past eight years. The book can be used for nondestructive testing technology and as an engineering reference work. The specific implementation of the electromagnetic ultrasonic guided wave system presented here will also be of value for other nondestructive test developers.

Hybrid superconducting magnetic suspensions

International Nuclear Information System (INIS)

Tixador, P.; Hiebel, P.; Brunet, Y.; Chaud, X.; Gautier-Picard, P.

1996-01-01

Superconductors, especially high T c ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO

The minimization of the extraneous electromagnetic fields of an inductive power transfer system

International Nuclear Information System (INIS)

McLean, James; Sutton, Robert

2013-01-01

The efficiency of inductive wireless power transfer (IPT) systems has been extensively studied. However, the electromagnetic compatibility of such systems is at least as important as the efficiency and has received much less attention. We consider the net magnetic dipole moment of the system as a figure of merit. That is, we seek to minimize the magnitude of the net dipole moment in order to minimize both the near magnetic fields and the radiated power. A 20 kHz, 3.3 kW, IPT system, representative of typical wireless vehicular battery charging systems, is considered and it is seen that one particular value of load impedance minimizes the net dipole moment while another, distinct, value maximizes efficiency. Thus, efficiency must be traded off, at least to some extent, in order to minimize extraneous electromagnetic fields.

Electromagnetic calibration system for sub-micronewton torsional thrust stand

Science.gov (United States)

Lam, J. K.; Koay, S. C.; Cheah, K. H.

2017-12-01

It is critical for a micropropulsion system to be evaluated. Thrust stands are widely recognised as the instrument to complete such tasks. This paper presents the development of an alternative electromagnetic calibration technique for thrust stands. Utilising the commercially made voice coils and permanent magnets, the proposed system is able to generate repeatable and also consistent steady-state calibration forces at over four orders of magnitude (30 - 23000 μN). The system is then used to calibrate a custom-designed torsional thrust stand, where its inherent ability in ease of setup is well demonstrated.

Suspension-thermal noise in spring–antispring systems for future gravitational-wave detectors

Science.gov (United States)

Harms, Jan; Mow-Lowry, Conor M.

2018-01-01

Spring–antispring systems have been investigated in the context of low-frequency seismic isolation in high-precision optical experiments. These systems provide the possibility to tune the fundamental resonance frequency to, in principle, arbitrarily low values, and at the same time maintain a compact design. It was argued though that thermal noise in spring–antispring systems would not be as small as one may naively expect from lowering the fundamental resonance frequency. In this paper, we present calculations of suspension-thermal noise for spring–antispring systems potentially relevant in future gravitational-wave detectors, i.e. the beam-balance tiltmeter, and the Roberts linkage. We find a concise expression of the suspension-thermal noise spectrum, which assumes a form very similar to the well-known expression for a simple pendulum. For systems such as the Roberts linkage foreseen as passive seismic isolation, we find that while they can provide strong seismic isolation due to a very low fundamental resonance frequency, their thermal noise is determined by the dimension of the system and is insensitive to fine-tunings of the geometry that can strongly influence the resonance frequency. By analogy, i.e. formal similarity of the equations of motion, this is true for all horizontal mechanical isolation systems with spring–antispring dynamics. This imposes strict requirements on mechanical spring–antispring systems for seismic isolation in potential future low-frequency gravitational-wave detectors as we discuss for the four main concepts, atom-interferometric, superconducting, torsion-bars, and conventional laser interferometer, and generally suggests that thermal noise needs to be evaluated carefully for high-precision experiments implementing spring–antispring dynamics.

3D modeling design and engineering analysis of automotive suspension beam

Directory of Open Access Journals (Sweden)

Ju Zhi Lan

2016-01-01

Full Text Available Automotive suspension is an important device for transmission and torque. The main parameters and dimensions of 40 tons of heavy duty truck spring suspension system are designed in the paper. According to the data, the 3D modeling and virtual assembly of the leaf spring suspension are carried out by using parametric design. Structural stress of spring suspension is analyzed which can provide a guide and basis for the design of the leaf spring suspension.

Evaluation of indeterminacy of initial data for cad system of electric engine suspension

Science.gov (United States)

Antipin, D. Ya; Izmerov, O. V.; Shorokhov, S. G.; Nadtochey, D. G.

2018-03-01

The research of the variants of the suspension of the traction electric motor of diesel locomotives was performed. It was found that the method of designing the suspension does not take into consideration the possible changes of the characteristics of the parts in operation conditions. Variants of the suspension design were proposed and patented, which provide the work reliability despite the operating conditions.

DESIGN AN INTELLIGENT CONTROLLER FOR FULL VEHICLE NONLINEAR ACTIVE SUSPENSION SYSTEMS

OpenAIRE

Aldair, A. A.; Wang, W. J.

2011-01-01

The main objective of designed the controller for a vehicle suspension system is to reduce the discomfort sensed by passengers which arises from road roughness and to increase the ride handling associated with the pitching and rolling movements. This necessitates a very fast and accurate controller to meet as much control objectives, as possible. Therefore, this paper deals with an artificial intelligence Neuro-Fuzzy (NF) technique to design a robust controller to meet the control objectives....

Nanomechanical electric and electromagnetic field sensor

Science.gov (United States)

Datskos, Panagiotis George; Lavrik, Nickolay

2015-03-24

The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

Superconducting magnet suspensions in high speed ground transport

Energy Technology Data Exchange (ETDEWEB)

Alston, I A

1973-08-01

A technical and economic definition of high speed ground transport systems using magnetic suspensions is given. The full range of common superconducting suspensions and of propulsions are covered with designs produced for speeds ranging from 100 m/s (225 miles/hr) to 250 m/s (560 mile/hr). Technical descriptions of the vehicles, their suspensions, propulsions and tracks are given in some detail and operating costs are presented for all the systems together with details of the breakdown of costs and the capital costs involved. The design assumptions, the costing procedure and a cost sensitivity study are presented. It is concluded that the systems are technically feasible; that they are suited to existing duorail track for low speed running and that, in these circumstances, they would be economically viable over many routes.

Addressing the susceptibility of digital systems to electromagnetic interference

International Nuclear Information System (INIS)

Ewing, P.D.; Korsah, K.; Antonescu, C.

1993-01-01

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Second, a verification and validation (V ampersand V) program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate acceptance should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation susceptibility attributable to EMI will be greatly reduced

Active and semi-active control of suspension systems for commercial vehicles based on preview

NARCIS (Netherlands)

Kok, J.J.; van Heck, J.G.A.M.; Muijderman, J.H.E.A.; Veldpaus, F.E.

1997-01-01

The performance of a vehicle axle/wheel suspension system is primarily determined by the comfort of the occupants, the required working space, the handling properties and, for commercial vehicles in particular, the dynamic tire forces and the load on the chassis components and on the cargo. General

Electromagnetic pulse research on electric power systems: Program summary and recommendations. Power Systems Technology Program

Energy Technology Data Exchange (ETDEWEB)

Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. [Oak Ridge National Lab., TN (United States); Tesche, F.M. [Tesche (F.M.), Dallas, TX (United States); Vance, E.F. [Vance (E.F.), Fort Worth, TX (United States)

1993-01-01

A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation`s power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation`s electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

Electromagnetic pulse research on electric power systems: Program summary and recommendations

Energy Technology Data Exchange (ETDEWEB)

Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. (Oak Ridge National Lab., TN (United States)); Tesche, F.M. (Tesche (F.M.), Dallas, TX (United States)); Vance, E.F. (Vance (E.F.), Fort Worth, TX (United States))

1993-01-01

A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation's power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation's electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

A multiobjective ? control strategy for energy harvesting in regenerative vehicle suspension systems

Science.gov (United States)

Casavola, Alessandro; Di Iorio, Fabio; Tedesco, Francesco

2018-04-01

A significant amount of energy induced by road unevenness and vehicle roll and pitch motions is usually dissipated by conventional shock-absorbers. In this paper, a novel active multiobjective ? control design methodology is proposed which explicitly includes, besides the usual control objectives on ride comfort, road handling and suspension stroke, the amount of energy to be harvested as an additional, though conflicting, control objective and allows the designer to directly trade-off among them depending on the application. An electromechanical regenerative suspension system is considered where the viscous damper is replaced by a linear electrical motor which is actively governed. It is shown that the proposed control law is able to achieve remarkable improvements on the amount of the harvested energy with respect to passive or semi-active control strategies while maintaining the other objectives at acceptable levels. Simulative studies undertaken via CarSim are also reported that confirm the potentiality and flexibility of the proposed control design strategy.

Latency and distortion of electromagnetic trackers for augmented reality systems

CERN Document Server

Himberg, Henry

2014-01-01

Augmented reality (AR) systems are often used to superimpose virtual objects or information on a scene to improve situational awareness. Delays in the display system or inaccurate registration of objects destroy the sense of immersion a user experiences when using AR systems. AC electromagnetic trackers are ideal for these applications when combined with head orientation prediction to compensate for display system delays. Unfortunately, these trackers do not perform well in environments that contain conductive or ferrous materials due to magnetic field distortion without expensive calibration

Design of Immune-Algorithm-Based Adaptive Fuzzy Controllers for Active Suspension Systems

Directory of Open Access Journals (Sweden)

Ming-Yuan Shieh

2014-04-01

Full Text Available The aim of this paper is to integrate the artificial immune systems and adaptive fuzzy control for the automobile suspension system, which is regarded as a multiobjective optimization problem. Moreover, the fuzzy control rules and membership controls are then introduced for identification and memorization. It leads fast convergence in the search process. Afterwards, by using the diversity of the antibody group, trapping into local optimum can be avoided, and the system possesses a global search capacity and a faster local search for finding a global optimal solution. Experimental results show that the artificial immune system with the recognition and memory functions allows the system to rapidly converge and search for the global optimal approximate solutions.

Design of LQG Controller for Active Suspension without Considering Road Input Signals

Directory of Open Access Journals (Sweden)

Hui Pang

2017-01-01

Full Text Available As the road conditions are completely unknown in the design of a suspension controller, an improved linear quadratic and Gaussian distributed (LQG controller is proposed for active suspension system without considering road input signals. The main purpose is to optimize the vehicle body acceleration, pitching angular acceleration, displacement of suspension system, and tire dynamic deflection comprehensively. Meanwhile, it will extend the applicability of the LQG controller. Firstly, the half-vehicle and road input mathematical models of an active suspension system are established, with the weight coefficients of each evaluating indicator optimized by using genetic algorithm (GA. Then, a simulation model is built in Matlab/Simulink environment. Finally, a comparison of simulation is conducted to illustrate that the proposed LQG controller can obtain the better comprehensive performance of vehicle suspension system and improve riding comfort and handling safety compared to the conventional one.

A precise electromagnetic field model useful for development of microwave imaging systems

DEFF Research Database (Denmark)

Chaber, Bartosz; Mohr, Johan Jacob

2016-01-01

was created in an iterative fashion in order to determine how much details are needed to make it reliable, while keeping it efficient.Findings - The authors found that the commercial software seems like a viable platform for developing electromagnetic solvers. The resulting computer model is easy to prepare......Purpose - The paper describes a fast forward electromagnetic model built with help of commercial software. The purpose of this paper is to create an efficient and robust electromagnetic field model that could be easily plugged into a working microwave imaging system. The secondary purpose...... is to evaluate advantages and disadvantages of such a commercial packages for creating such a model.Design/methodology/approach - In this paper the authors decided to build the model using COMSOL Multiphysics software suite, ultimately comparing its result to measurements of a real device. The numerical model...

Addressing the susceptibility of digital systems to electromagnetic interference

International Nuclear Information System (INIS)

Ewing, P.D.; Korsah, K.; Antonescu, C.

1993-01-01

This paper discusses the development of the technical basis for acceptance criteria applicable to the immunization of digital systems against electromagnetic interference (EMI). The work is sponsored by the US Nuclear Regulatory Commission and stems from the safety-related issues that need to be addressed as a result of the application of digital instrumentation and control systems in nuclear power plants. Designers of digital circuits are incorporating increasingly higher clock frequencies and lower logic level voltages, thereby leading to potentially greater susceptibility of spurious interference being misinterpreted as legitimate logic. Development of the technical basis for acceptance criteria to apply to these digital systems centers around establishing good engineering practices to ensure that sufficient levels of electromagnetic compatibility (EMC) are maintained between the nuclear power plant's electronic and electromechanical systems. First, good EMC design and installation practices are needed to control the emissions from interference sources and thereby their impact on other nearby circuits and systems. Second, a verification and validation (V ampersand V) program is needed to outline the EMI tests to be performed, the associated test methods to be followed, and adequate acceptance criteria to ensure that the circuit or system under test meets the recommended guidelines. V ampersand V should be followed by periodic maintenance to assess whether the recommended EMI control practices continue to be adhered to as part of the routine operation of the nuclear power plant. By following these steps, the probability of encountering safety-related instrumentation susceptibility attributable to EMI will be greatly reduced

Fast breeder reactor electromagnetic pump

International Nuclear Information System (INIS)

Araseki, Hideo; Murakami, Takahiro

2008-01-01

Main pumps circulating sodium in the FBR type reactor have been mechanical types, not electromagnetic pumps. Electromagnetic pump of 1-2 m 3 /min has been used as an auxiliary pump. Large sized electromagnetic pumps such as several hundred m 3 /min have not been commercialized due to technical difficulties with electromagnetic instability and pressure pulsations. This article explained electromagnetic and fluid equations and magnetic Reynolds number related with electromagnetic pumps and numerical analysis of instability characteristics and pressure pulsations and then described applications of the results to FBR system. Magnetic Reynolds number must be chosen less than one with appropriate operating frequency and optimum slip of 0.2-0.4. (T. Tanaka)

Feasibility Study of the Electromagnetic Damper for Cable Structures Using Real-Time Hybrid Simulation.

Science.gov (United States)

Jung, Ho-Yeon; Kim, In-Ho; Jung, Hyung-Jo

2017-10-31

Cable structure is a major component of long-span bridges, such as cable-stayed and suspension bridges, and it transfers the main loads of bridges to the pylons. As these cable structures are exposed to continuous external loads, such as vehicle and wind loads, vibration control and continuous monitoring of the cable are required. In this study, an electromagnetic (EM) damper was designed and fabricated for vibration control and monitoring of the cable structure. EM dampers, also called regenerative dampers, consist of permanent magnets and coils. The electromagnetic force due to the relative motion between the coil and the permanent magnet can be used to control the vibration of the structure. The electrical energy can be used as a power source for the monitoring system. The effects of the design parameters of the damper were numerically analyzed and the damper was fabricated. The characteristics of the damper were analyzed with various external load changes. Finally, the vibration-control and energy-harvesting performances of the cable structure were evaluated through a hybrid simulation. The vibration-control and energy-harvesting performances for various loads were analyzed and the applicability to the cable structure of the EM damper was evaluated.

Estimation of Road Loads and Vibration Transmissibility of Torsion Bar Suspension System in a Tracked Vehicle

Science.gov (United States)

Gagneza, G. P. S.; Chandramohan, Sujatha

2018-05-01

Designing the suspension system of a tracked combat vehicle (CV) is really challenging as it has to satisfy conflicting requirements of good ride comfort, vehicle handling and stability characteristics. Many studies in this field have been reported in literature and it has been found that torsion bars satisfy the designer's conflicting requirements of good ride and handling and thus have reserved a place for themselves as the most widely used suspension system for military track vehicles. Therefore, it is imperative to evaluate the effectiveness of the torsion bar under dynamic conditions of undulating terrain and validating the same by correlating it with computer simulation results. Thus in the present work, the dynamic simulation of a 2N + 4 degrees of freedom (DOF) mathematical model has been carried out using MATLAB Simulink and the vibration levels were also measured experimentally on a 12 wheel stationed high mobility military tracked infantry combat vehicle (ICV BMP-II) traversing different terrain, that is, Aberdeen proving ground (APG) and Sinusoidal, at a constant vehicle speed. The dynamic force transmitted to the hull CG through the 12 torsion bar suspension systems was computed to be around 26,700 N and found to match the measured values. The vibration isolation of the torsion bar in bounce was found to be effective, with a transmissibility from the road wheel to the hull of about 0.6.

Microbial spoilage, instability risk of antacid suspension in the presence of commonly used preservative system.

Science.gov (United States)

Khan, Jamshaid Ali; Khan, Imran Ullah; Iqbal, Zafar; Nasir, Fazli; Muhammad, Salar; Hannan, Peer Abdul; Ullah, Irfan

2015-09-01

Manifestation of microbial spoilage of any product by bacteria and to assess the effectiveness of the anti-microbial preservatives (parabens) used for the prevention and stability purpose. The aim of the present work is to study the effectiveness of preservatives used in the antacid suspensions and to analyze the effect of microbial growth on the quality of respective antacid suspensions. Samples of various antacid suspensions were randomly collected from local market and Government hospital pharmacies. Three different antacid formulations were prepared in the laboratory. All the formulations were preliminarily evaluated on the basis of organoleptic characteristics, pH, viscosity and assay. Efficacy of the preservative system in suspension formulation was determined by inoculating the samples in its final container, with specific strains of bacteria i.e. Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538, taking samples from the inoculated preparation at specified intervals of time i.e. 0 time, 07 days, 14 days and 28 days, growing it on nutrient agar medium and colony forming units (CFUs) were scored by plate count. At the same time the samples were also subjected to qualitative and quantitative testing. The decrease in CFU and alteration in assay, pH and viscosity was observed in all the formulations except formulation M2 and F3 that showed stability throughout the study period.

Structural analysis of compression helical spring used in suspension system

Science.gov (United States)

Jain, Akshat; Misra, Sheelam; Jindal, Arun; Lakhian, Prateek

2017-07-01

The main aim of this work has to develop a helical spring for shock absorber used in suspension system which is designed to reduce shock impulse and liberate kinetic energy. In a vehicle, it increases comfort by decreasing amplitude of disturbances and it improves ride quality by absorbing and dissipating energy. When a vehicle is in motion on a road and strikes a bump, spring comes into action quickly. After compression, spring will attempt to come to its equilibrium state which is on level road. Helical springs can be made lighter with more strength by reducing number of coils and increasing the area. In this research work, a helical spring is modeled and analyzed to substitute the existing steel spring which is used in suspension. By using different materials, stress and deflection of helical spring can be varied. Comparability between existing spring and newly replaced spring is used to verify the results. For finding detailed stress distribution, finite element analysis is used to find stresses and deflection in both the helical springs. Finite element analysis is a method which is used to find proximate solutions of a physical problem defined in a finite domain. In this research work, modeling of spring is accomplished using Solid Works and analysis on Ansys.

Influence of Electric, Magnetic, and Electromagnetic Fields on the Circadian System: Current Stage of Knowledge

Science.gov (United States)

Żak, Arkadiusz

2014-01-01

One of the side effects of each electrical device work is the electromagnetic field generated near its workplace. All organisms, including humans, are exposed daily to the influence of different types of this field, characterized by various physical parameters. Therefore, it is important to accurately determine the effects of an electromagnetic field on the physiological and pathological processes occurring in cells, tissues, and organs. Numerous epidemiological and experimental data suggest that the extremely low frequency magnetic field generated by electrical transmission lines and electrically powered devices and the high frequencies electromagnetic radiation emitted by electronic devices have a potentially negative impact on the circadian system. On the other hand, several studies have found no influence of these fields on chronobiological parameters. According to the current state of knowledge, some previously proposed hypotheses, including one concerning the key role of melatonin secretion disruption in pathogenesis of electromagnetic field induced diseases, need to be revised. This paper reviews the data on the effect of electric, magnetic, and electromagnetic fields on melatonin and cortisol rhythms—two major markers of the circadian system as well as on sleep. It also provides the basic information about the nature, classification, parameters, and sources of these fields. PMID:25136557

Network synthesis and parameter optimization for vehicle suspension with inerter

Directory of Open Access Journals (Sweden)

Long Chen

2016-12-01

Full Text Available In order to design a comfortable-oriented vehicle suspension structure, the network synthesis method was utilized to transfer the problem into solving a timing robust control problem and determine the structure of “inerter–spring–damper” suspension. Bilinear Matrix Inequality was utilized to obtain the timing transfer function. Then, the transfer function of suspension system can be physically implemented by passive elements such as spring, damper, and inerter. By analyzing the sensitivity and quantum genetic algorithm, the optimized parameters of inerter–spring–damper suspension were determined. A quarter-car model was established. The performance of the inerter–spring–damper suspension was verified under random input. The simulation results manifested that the dynamic performance of the proposed suspension was enhanced in contrast with traditional suspension. The root mean square of vehicle body acceleration decreases by 18.9%. The inerter–spring–damper suspension can inhibit the vertical vibration within the frequency of 1–3 Hz effectively and enhance the performance of ride comfort significantly.

Basic Electromagnetism and Materials

CERN Document Server

Moliton, André

2007-01-01

Basic Electromagnetism and Materials is the product of many years of teaching basic and applied electromagnetism. This textbook can be used to teach electromagnetism to a wide range of undergraduate science majors in physics, electrical engineering or materials science. However, by making lesser demands on mathematical knowledge than competing texts, and by emphasizing electromagnetic properties of materials and their applications, this textbook is uniquely suited to students of materials science. Many competing texts focus on the study of propagation waves either in the microwave or optical domain, whereas Basic Electromagnetism and Materials covers the entire electromagnetic domain and the physical response of materials to these waves. Professor André Moliton is Director of the Unité de Microélectronique, Optoélectronique et Polymères (Université de Limoges, France), which brings together three groups studying the optoelectronics of molecular and polymer layers, micro-optoelectronic systems for teleco...

Modeling of MEMS piezoelectric energy harvesters using electromagnetic and power system theories

KAUST Repository

Ahmad, Mahmoud Al

2012-07-23

This work proposes a novel methodology for estimating the power output of piezoelectric generators. An analytical model that estimates for the first time the loss ratio and output power of piezoelectric generators based on the direct mechanical-to-electrical analogy, electromagnetic theory, and power system theory is developed. The mechanical-to-electrical analogy and power system theory allow the derivation of an equivalent input impedance expression for the network, whereas electromagnetic transmission line theory allows deduction of the equivalent electromechanical loss of the piezoelectric generator. By knowing the mechanical input power and the loss of the network, calculation of the output power of the piezoelectric device becomes a straightforward procedure. Experimental results based on published data are also presented to validate the analytical solution. In order to fully benefit from the well-established electromagnetic transmission line and electric circuit theories, further analyses on the resonant frequency, bandwidth, and sensitivity are presented. Compared to the conventional modeling methods currently being adopted in the literature, the proposed method provides significant additional information that is crucial for enhanced device operation and quick performance optimization. © 2011 IOP Publishing Ltd.

Effects of exposure to 2100 MHz GSM-like radiofrequency electromagnetic field on auditory system of rats

Directory of Open Access Journals (Sweden)

Metin Çeliker

Full Text Available Abstract Introduction: The use of mobile phones has become widespread in recent years. Although beneficial from the communication viewpoint, the electromagnetic fields generated by mobile phones may cause unwanted biological changes in the human body. Objective: In this study, we aimed to evaluate the effects of 2100 MHz Global System for Mobile communication (GSM-like electromagnetic field, generated by an electromagnetic fields generator, on the auditory system of rats by using electrophysiological, histopathologic and immunohistochemical methods. Methods: Fourteen adult Wistar albino rats were included in the study. The rats were divided randomly into two groups of seven rats each. The study group was exposed continuously for 30 days to a 2100 MHz electromagnetic fields with a signal level (power of 5.4 dBm (3.47 mW to simulate the talk mode on a mobile phone. The control group was not exposed to the aforementioned electromagnetic fields. After 30 days, the Auditory Brainstem Responses of both groups were recorded and the rats were sacrificed. The cochlear nuclei were evaluated by histopathologic and immunohistochemical methods. Results: The Auditory Brainstem Responses records of the two groups did not differ significantly. The histopathologic analysis showed increased degeneration signs in the study group (p = 0.007. In addition, immunohistochemical analysis revealed increased apoptotic index in the study group compared to that in the control group (p = 0.002. Conclusion: The results support that long-term exposure to a GSM-like 2100 MHz electromagnetic fields causes an increase in neuronal degeneration and apoptosis in the auditory system.

Rheology of dense suspensions of non colloidal particles

Science.gov (United States)

Guazzelli, Élisabeth

2017-06-01

Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing) and in natural phenomena (e.g. flows of slurries, debris, and lava). Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers) or non-Newtonian fluids that we will also address.

Establishment of sorghum cell suspension culture system for ...

African Journals Online (AJOL)

STORAGESEVER

2008-03-18

Mar 18, 2008 ... Additionally, sorghum cell suspension cultures have been initiated from the friable ... proteomics technologies. The field of proteomics is .... air dried at room temperature and resuspended in 2 ml of urea buffer [9 M urea, 2 M ...

Study on coupled shock absorber system using four electromagnetic dampers

International Nuclear Information System (INIS)

Fukumori, Y; Hayashi, R; Okano, H; Suda, Y; Nakano, K

2016-01-01

Recently, the electromagnetic damper, which is composed of an electric motor, a ball screw, and a nut, was proposed. The electromagnetic damper has high responsiveness, controllability, and energy saving performance. It has been reported that it improved ride comfort and drivability. In addition, the authors have proposed a coupling method of two electromagnetic dampers. The method enables the characteristics of bouncing and rolling or pitching motion of a vehicle to be tuned independently. In this study, the authors increase the number of coupling of electromagnetic dampers from two to four, and propose a method to couple four electromagnetic dampers. The proposed method enables the characteristics of bouncing, rolling and pitching motion of a vehicle to be tuned independently. Basic experiments using proposed circuit and motors and numerical simulations of an automobile equipped with the proposed coupling electromagnetic damper are carried out. The results indicate the proposed method is effective. (paper)

Understanding possible electromagnetic counterparts to loud gravitational wave events: Binary black hole effects on electromagnetic fields

International Nuclear Information System (INIS)

Palenzuela, Carlos; Lehner, Luis; Yoshida, Shin

2010-01-01

In addition to producing loud gravitational waves, the dynamics of a binary black hole system could induce emission of electromagnetic radiation by affecting the behavior of plasmas and electromagnetic fields in their vicinity. We study how the electromagnetic fields are affected by a pair of orbiting black holes through the merger. In particular, we show how the binary's dynamics induce a variability in possible electromagnetically induced emissions as well as an enhancement of electromagnetic fields during the late-merge and merger epochs. These time dependent features will likely leave their imprint in processes generating detectable emissions and can be exploited in the detection of electromagnetic counterparts of gravitational waves.

Vehicle lateral dynamics stabilization using active suspension

Directory of Open Access Journals (Sweden)

Drobný V.

2008-12-01

Full Text Available The paper deals with the investigation of active nonlinear suspension control in order to stabilize the lateral vehicle motion in similar way as systems like ESP do. The lateral stabilization of vehicle based on braking forces can be alternatively provided by the different setting of suspension forces. The basis of this control is the nonlinear property of the tyres. The vehicle has at least four wheels and it gives one or more redundant vertical forces that can be used for the different distribution of vertical suspension forces in such a way that resulting lateral and/or longitudinal forces create the required correction moment for lateral dynamic vehicle stabilization.

Study of electromagnetic noise influence on quench detection system under different discharge conditions for EAST

International Nuclear Information System (INIS)

Hu, Yanlan; Li, Jiangang; Shen, Biao; Lv, Huanyu; Xiao, Y.Z.

2013-01-01

Highlights: ► Reliable quench detection in EAST is a key issue for steady-state operation. ► The electromagnet noise interference associated with detection signals under different discharge conditions are evaluated. ► The effective measures have been realized on detection systems. ► Recently upgrade work has been done, especially for the optimization of ACS and false FSDS were reduced greatly. -- Abstract: EAST is the first Tokamak device whose toroidal and poloidal magnet are superconducting. The enormous magnetic field energy stored in the magnet system will transfer into thermal energy and cause the damage of superconducting magnet, if a quench happened. Therefore, reliable quench detection is a key issue for steady-state operation. In addition to electromagnetic noise from poloidal magnet fields and plasma current which will experience fast current ramp rate, radio frequency noise from heating system also have some interference on quench detection system to a certain degree. The most difficult point for quench detection system is required to have more detail evaluation on electromagnetic noise interference. Recently experiments have been carried out successfully in EAST device. The steady-state operation with 1 MA of plasma current and more than 100-s plasma duration has been obtained. In the paper, the electromagnetic noise interference on quench detection system under different discharge conditions are analyzed and relative process methods are also introduced. The technological experience and experimental data are significant for the constructing ITER and similar superconducting device have been mentioned which will supply significant technological experience and experimental data for constructing ITER and similar superconducting device

Research on the Countermeasures against Electromagnetic Interface in Power Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Bin; Kang, Young Suk; Choi, Hyo Yul; Cha, Ok Hyun [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Lee, Gi Chul; Le, Jae Bok; Ha, Tae Hyun; Kim, Suk Joo; Na, Dae Yul; Kim, Yong Ho; Jeong, Kyo Beom [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

1997-12-31

As the results of widespread use of microelectronics in electric power system, electric environment of power operation facilities in substation has become more weak and severe for surge voltages. Electromagnetic coupled overvoltage caused by HV bus switching operating lead to the malfunction or destruction of low voltage control circuit which mostly used signal. To scope with this transients overvoltage, it is necessary to be investigated transient source and propagation path and analysed its effects to low voltage circuit such as relay. This study is to analysis source of conducted EMP(electromagnetic pulse) on the low voltage control circuit and to acquits transient voltage waveforms, and to provide countermeasures against transient voltage, and EMP filtering method according to each EMP each type. With this, gradual improvement of EMI countermeasure will be achieved. (author). 49 refs., figs.

Research on the Countermeasures against Electromagnetic Interface in Power Systems

Energy Technology Data Exchange (ETDEWEB)

Lee, Won Bin; Kang, Young Suk; Choi, Hyo Yul; Cha, Ok Hyun [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Lee, Gi Chul; Le, Jae Bok; Ha, Tae Hyun; Kim, Suk Joo; Na, Dae Yul; Kim, Yong Ho; Jeong, Kyo Beom [Korea Electrotechnology Research Institute, Changwon (Korea, Republic of)

1996-12-31

As the results of widespread use of microelectronics in electric power system, electric environment of power operation facilities in substation has become more weak and severe for surge voltages. Electromagnetic coupled overvoltage caused by HV bus switching operating lead to the malfunction or destruction of low voltage control circuit which mostly used signal. To scope with this transients overvoltage, it is necessary to be investigated transient source and propagation path and analysed its effects to low voltage circuit such as relay. This study is to analysis source of conducted EMP(electromagnetic pulse) on the low voltage control circuit and to acquits transient voltage waveforms, and to provide countermeasures against transient voltage, and EMP filtering method according to each EMP each type. With this, gradual improvement of EMI countermeasure will be achieved. (author). 49 refs., figs.

Applications of Advanced Electromagnetics Components and Systems

CERN Document Server

Kouzaev, Guennadi A

2013-01-01

This text, directed to the microwave engineers and Master and PhD students, is on the use of electromagnetics to the development and design of advanced integrated components distinguished by their extended field of applications. The results of hundreds of authors scattered in numerous journals and conference proceedings are carefully reviewed and classed.  Several chapters are to refresh the knowledge of readers in advanced electromagnetics. New techniques are represented by compact electromagnetic–quantum equations which can be used in modeling of microwave-quantum integrated circuits of future In addition, a topological method to the boundary value problem analysis is considered with the results and examples.  One extended chapter is for the development and design of integrated components for extended bandwidth applications, and the technology and electromagnetic issues of silicon integrated transmission lines, transitions, filters, power dividers, directional couplers, etc are considered. Novel prospec...

Active Electromechanical Suspension System for Planetary Rovers, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Balcones Technologies, LLC proposes to adapt actively controlled suspension technology developed by The University of Texas at Austin Center for Electromechanics...

Limits on new forces coexisting with electromagnetism

International Nuclear Information System (INIS)

Kloor, H.; Fischbach, E.; Talmadge, C.; Greene, G.L.

1994-01-01

We consider the limits arising from different electromagnetic systems on the existence of a possible new electromagnetic analogue of the fifth force. Although such a force may have no intrinsic connection to electromagnetism (or gravity), its effects could be manifested through various anomalies in electromagnetic systems, for appropriate values of the coupling strength and range. Our work generalizes that of Bartlett and Loegl (who considered the case of a massive vector field coexisting with massless electrodynamics) to encompass a broad class of phenomenological interactions mediated by both scalar and vector exchanges. By combining data from both gravitational and electromagnetic systems, one can eventually set limits on a new force whose range λ extends from the subatomic scale (λ∼10 -15 m) to the astrophysical scale (λ∼10 12 m)

High-order FDTD methods for transverse electromagnetic systems in dispersive inhomogeneous media.

Science.gov (United States)

Zhao, Shan

2011-08-15

This Letter introduces a novel finite-difference time-domain (FDTD) formulation for solving transverse electromagnetic systems in dispersive media. Based on the auxiliary differential equation approach, the Debye dispersion model is coupled with Maxwell's equations to derive a supplementary ordinary differential equation for describing the regularity changes in electromagnetic fields at the dispersive interface. The resulting time-dependent jump conditions are rigorously enforced in the FDTD discretization by means of the matched interface and boundary scheme. High-order convergences are numerically achieved for the first time in the literature in the FDTD simulations of dispersive inhomogeneous media. © 2011 Optical Society of America

Electromagnetic Radiation Interface System and Method

National Research Council Canada - National Science Library

Steinbrecher, Donald H

2005-01-01

.... The termination section may comprise an electrical resistance for capturing substantially all the electromagnetic wave energy received by each respective bristle to thereby prevent reflections...

Compressed Air Production Using Vehicle Suspension

OpenAIRE

Ninad Arun Malpure; Sanket Nandlal Bhansali

2015-01-01

Abstract Generally compressed air is produced using different types of air compressors which consumes lot of electric energy and is noisy. In this paper an innovative idea is put forth for production of compressed air using movement of vehicle suspension which normal is wasted. The conversion of the force energy into the compressed air is carried out by the mechanism which consists of the vehicle suspension system hydraulic cylinder Non-return valve air compressor and air receiver. We are co...

Perturbing an electromagnetically induced transparency in a Λ system using a low-frequency driving field. II. Four-level system

International Nuclear Information System (INIS)

Wilson, E. A.; Manson, N. B.; Wei, C.

2005-01-01

The effect a perturbing field has on an electromagnetically induced transparency within a three-level Λ system is presented. The perturbing field is applied resonant between one of the lower levels of the Λ system and a fourth level. The electromagnetically induced transparency feature is split and this is measured experimentally for both single and bichromatic driving fields. In the single-driving-field case a density matrix treatment is shown to be in reasonable agreement with experiment and in both single and bichromatic cases the structure in the spectrum can be explained using a dressed-state analysis

Modeling and characterization of an electromagnetic system for the estimation of Frequency Response Function of spindle

Science.gov (United States)

Tlalolini, David; Ritou, Mathieu; Rabréau, Clément; Le Loch, Sébastien; Furet, Benoit

2018-05-01

The paper presents an electromagnetic system that has been developed to measure the quasi-static and dynamic behavior of machine-tool spindle, at different spindle speeds. This system consists in four Pulse Width Modulation amplifiers and four electromagnets to produce magnetic forces of ± 190 N for the static mode and ± 80 N for the dynamic mode up to 5 kHz. In order to measure the Frequency Response Function (FRF) of spindle, the applied force is required, which is a key issue. A dynamic force model is proposed in order to obtain the load from the measured current in the amplifiers. The model depends on the exciting frequency and on the magnetic characteristics of the system. The predicted force at high speed is validated with a specific experiment and the performance limits of the experimental device are investigated. The FRF obtained with the electromagnetic system is compared to a classical tap test measurement.

Electromagnetic support and/or guide system for levitating vehicles. Elektromagnetisches Trag- und/oder Fuehrungssystem fuer Schwebefahrzeuge

Energy Technology Data Exchange (ETDEWEB)

Breitling, U; Simon, K

1978-01-26

The invention refers to an electromagnetic support and/or guide system for levitating vehicles (MAGLEV system). These levitating vehicles can move along tracks with at least one fixed branch-off. The parts of the system on the vehicle are arranged symmetrically to the vehicle's longitudinal axis above or below the vehicle body. There are 2 parallel rows of magnets provided for each longitudinal side of the vehicle, where only one magnet can act on the track outside the branch-off, and both magnets can act alternately on the track within the branch-off. The purpose of the invention is to develop such a system so that interference forces on the core parts are avoided. According to the invention this is achieved by the first row of each parallel longitudinal row of electromagnets and the armature rails allocated to the first row having a different pole spacing from the second row of electromagnets of the parallel row concerned and the armature rails of the associated second row.

Crust formation in drying colloidal suspensions

KAUST Repository

Style, R. W.

2010-06-30

During the drying of colloidal suspensions, the desiccation process causes the suspension near the air interface to consolidate into a connected porous matrix or crust. Fluid transport in the porous medium is governed by Darcy\\'s law and the equations of poroelasticity, while the equations of colloid physics govern processes in the suspension. We derive new equations describing this process, including unique boundary conditions coupling the two regions, yielding a moving-boundary model of the concentration and stress profiles during drying. A solution is found for the steady-state growth of a nedimensional crust during constant evaporation rate from the surface. The solution is used to demonstrate the importance of the system boundary conditions on stress profiles and diffusivity in a drying crust. © 2011 The Royal Society.

Nanoscale/multilayer gradient materials for application in electromagnetic gun systems

Energy Technology Data Exchange (ETDEWEB)

Otooni, M.A. [Army Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ (United States); Brown, I.G.; Anders, S.; Wang, Z. [Lawrence Berkeley Lab., CA (United States)

1996-12-31

Analysis of fired rails from electromagnetic railguns indicates severe surface damage occurs due to high current arcing and tribological mismatch. The authors have explored the behavior of several nanoscale multilayered materials as possible routes to improve the thermomechanical properties of the rail and armature materials. Structures investigated include (i) Ti-Co alloy on Ta-Cu alloy on dlc (diamond-like carbon) on stainless steel; (ii) Ti-Co alloy on Ta-Cu alloy on dlc on Cu, (iii) Ti-Co alloy on Ta-Cu on Cu; and (iv) Ti-Co on Ta-Cu alloy on Al. The alloys were all 50:50 at% and film thicknesses were fin the range 400--1,000 {angstrom}. The films were formed using a repetitively pulsed vacuum arc plasma deposition method with substrate biasing- and IBAD-like techniques. The surfaces were characterized by scanning electron microscopy, transmission electron microscopy, Rutherford backscattering spectroscopy, optical microscopy, microhardness measurements, arc erosion resistance and scratch resistance tests. Preliminary results show improvement in the microhardness, arc erosion resistance and scratch resistance, most especially for the dlc-coated surfaces. This kind of multilayered approach to the fabrication of electromagnetic railgun and armature surfaces could be important for future advanced Electromagnetic EM Gun systems.

Rheology of dense suspensions of non colloidal particles

Directory of Open Access Journals (Sweden)

Guazzelli Élisabeth

2017-01-01

Full Text Available Dense suspensions are materials with broad applications both in industrial processes (e.g. waste disposal, concrete, drilling muds, metalworking chip transport, and food processing and in natural phenomena (e.g. flows of slurries, debris, and lava. Despite its long research history and its practical relevance, the mechanics of dense suspensions remain poorly understood. The major difficulty is that the grains interact both by hydrodynamic interactions through the liquid and by mechanical contact. These systems thus belong to an intermediate regime between pure suspensions and granular flows. We show that we can unify suspension and granular rheology under a common framework by transferring the frictional approach of dry granular media to wet suspensions of spherical particles. We also discuss non-Newtonian behavior such as normal-stress differences and shear-induced migration. Beyond the classical problem of dense suspension of hard spheres which is far from being completely resolved, there are also entirely novel avenues of study concerning more complex mixtures of particles and fluids such as those involving other types of particles (e.g. fibers or non-Newtonian fluids that we will also address.

Evaluating damping elements for two-stage suspension vehicles

Directory of Open Access Journals (Sweden)

Ronald M. Martinod R.

2012-01-01

Full Text Available The technical state of the damping elements for a vehicle having two-stage suspension was evaluated by using numerical models based on the multi-body system theory; a set of virtual tests used the eigenproblem mathematical method. A test was developed based on experimental modal analysis (EMA applied to a physical system as the basis for validating the numerical models. The study focused on evaluating vehicle dynamics to determine the influence of the dampers’ technical state in each suspension state.

Dynamic model and workspace analysis of novel incompletely restrained cable-suspension swing system driven by two cables

Directory of Open Access Journals (Sweden)

Naige Wang

2017-03-01

Full Text Available The incompletely restrained cable-suspension swing system driven by two cables is introduced in this article. Based on wrench of forces theory and Lagrange’s equation of first kind, the static and dynamics models of incompletely restrained cable-suspension swing system driven by two cables are established, respectively. In order to obtain an intuitive understanding of the trajectory analysis, a dynamics model consisting of governing equation and geometric constraint conditions which is a set of the mixed differential-algebraic equation in mathematics is established. A typical feedback controller and an inverse model were set up to estimate the driving function. The effective workspace, which is used to guarantee an efficient swing process, mostly depends on the geometrical shape rather than the volume itself which was calculated by trajectory analysis. In order to estimate system features and ensure a limited range of tension in underconstrained spatial cable system, the probable location of unbalanced loading was evaluated by pointwise evaluation techniques during normal work.

Multiobjective suspension control problem

NARCIS (Netherlands)

Jager, de A.G.

1995-01-01

The paper describes a (controller) design problem in the field of suspension systems for transport vehicles. A ten degrees-of-freedom model for a tractor-semitrailer vehicle is presented, using parameters derived from a real vehicle, which should be used for design and verification purposes. Road

Spectral analysis connected with suspension bridge systems

Czech Academy of Sciences Publication Activity Database

Malík, Josef

2016-01-01

Roč. 81, č. 1 (2016), s. 42-75 ISSN 0272-4960 R&D Projects: GA MŠk ED2.1.00/03.0082 Institutional support: RVO:68145535 Keywords : suspension bridge * vertical and torsional oscillation * eigenvalue * eigenvector * flutter Subject RIV: JM - Building Engineering Impact factor: 0.945, year: 2016 http://imamat.oxfordjournals.org/content/early/2015/09/16/imamat.hxv027.short?rss=1

Minimally invasive brow suspension for facial paralysis.

Science.gov (United States)

Costantino, Peter D; Hiltzik, David H; Moche, Jason; Preminger, Aviva

2003-01-01

To report a new technique for unilateral brow suspension for facial paralysis that is minimally invasive, limits supraciliary scar formation, does not require specialized endoscopic equipment or expertise, and has proved to be equal to direct brow suspension in durability and symmetry. Retrospective survey of a case series of 23 patients between January 1997 and December 2000. Metropolitan tertiary care center. Patients with head and neck tumors and brow ptosis caused by facial nerve paralysis. The results of the procedure were determined using the following 3-tier rating system: outstanding (excellent elevation and symmetry); acceptable (good elevation and fair symmetry); and unacceptable (loss of elevation). The results were considered outstanding in 12 patients, acceptable in 9 patients, and unacceptable in only 1 patient. One patient developed a hematoma, and 1 patient required a secondary adjustment. The technique has proved to be superior to standard brow suspension procedures with regard to scar formation and equal with respect to facial symmetry and suspension. These results have caused us to abandon direct brow suspension and to use this minimally invasive method in all cases of brow ptosis due to facial paralysis.

Particle interactions in concentrated suspensions

International Nuclear Information System (INIS)

Mondy, L.A.; Graham, A.L.; Abbott, J.R.; Brenner, H.

1993-01-01

An overview is presented of research that focuses on slow flows of suspensions in which colloidal and inertial effects are negligibly small. The authors describe nuclear magnetic resonance imaging experiments to quantitatively measure particle migration occurring in concentrated suspensions undergoing a flow with a nonuniform shear rate. These experiments address the issue of how the flow field affects the microstructure of suspensions. In order to understand the local viscosity in a suspension with such a flow-induced, spatially varying concentration, one must know how the viscosity of a homogeneous suspension depends on such variables as solids concentration and particle orientation. The authors suggest the technique of falling ball viscometry, using small balls, as a method to determine the effective viscosity of a suspension without affecting the original microstructure significantly. They also describe data from experiments in which the detailed fluctuations of a falling ball's velocity indicate the noncontinuum nature of the suspension and may lead to more insights into the effects of suspension microstructure on macroscopic properties. Finally, they briefly describe other experiments that can be performed in quiescent suspensions (in contrast to the use of conventional shear rotational viscometers) in order to learn more about boundary effects in concentrated suspensions

Measurement and control systems for an imaging electromagnetic flow metre.

Science.gov (United States)

Zhao, Y Y; Lucas, G; Leeungculsatien, T

2014-03-01

Electromagnetic flow metres based on the principles of Faraday's laws of induction have been used successfully in many industries. The conventional electromagnetic flow metre can measure the mean liquid velocity in axisymmetric single phase flows. However, in order to achieve velocity profile measurements in single phase flows with non-uniform velocity profiles, a novel imaging electromagnetic flow metre (IEF) has been developed which is described in this paper. The novel electromagnetic flow metre which is based on the 'weight value' theory to reconstruct velocity profiles is interfaced with a 'Microrobotics VM1' microcontroller as a stand-alone unit. The work undertaken in the paper demonstrates that an imaging electromagnetic flow metre for liquid velocity profile measurement is an instrument that is highly suited for control via a microcontroller. © 2013 ISA Published by ISA All rights reserved.

Novel annular flow electromagnetic measurement system for drilling engineering.

OpenAIRE

Ge, L.; Wei, G. H.; Wang, Q.; Hu, Z.; Li, J. L.

2017-01-01

Downhole micro-flux control drilling technology can effectively solve drilling accidents, such as kick and loss in narrow density window drilling scenarios. Using a downhole annular flow measurement system to obtain real-time information of downhole annular flow is the core and foundation of downhole micro-flux control drilling technology. The research work of electromagnetic flowmeters in recent years creates a challenge for downhole annular flow measurement. This paper proposes a new method...

Load-cell based characterization system for a "Violin-Mode" shadow-sensor in advanced LIGO suspensions

Science.gov (United States)

Lockerbie, N. A.; Tokmakov, K. V.

2016-07-01

The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre's holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

Electromagnetic Compatibility of Devices on Hybrid Electromagnetic Components

Science.gov (United States)

Konesev, S. G.; Khazieva, R. T.; Kirillov, R. V.; Gainutdinov, I. Z.; Kondratyev, E. Y.

2018-01-01

There is a general tendency to reduce the weight and dimensions, the consumption of conductive and electrical insulating materials, increase the reliability and energy efficiency of electrical devices. In recent years, designers have been actively developing devices based on hybrid electromagnetic components (HEMC) such as inductive-capacitive converters (ICC), voltages pulse generators (VPG), secondary power supplies (SPS), capacitive storage devices (CSD), induction heating systems (IHS). Sources of power supplies of similar electrical devices contain, as a rule, links of increased frequency and function in key (pulse) modes, which leads to an increase in electromagnetic interference (EMI). Nonlinear and periodic (impulse) loads, non-sinusoidal (pulsation) of the electromotive force and nonlinearity of the internal parameters of the source and input circuits of consumers distort the shape of the input voltage lead to an increase in thermal losses from the higher harmonic currents, aging of the insulation, increase in the weight of the power supply filter units, resonance at higher harmonics. The most important task is to analyze the operation of electrotechnical devices based on HEMC from the point of view of creating EMIs and assessing their electromagnetic compatibility (EMC) with power supply systems (PSS). The article presents the results of research on the operation of an IHS, the operation principle of a secondary power supply source of which is based on the operation of a half-bridge autonomous inverter, the switching circuit of which is made in the form of a HEMC, called the «multifunctional integrated electromagnetic component»" (MIEC).

Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

Science.gov (United States)

Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

2017-07-01

According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable.

Electromagnetic Performance Calculation of HTS Linear Induction Motor for Rail Systems

International Nuclear Information System (INIS)

Liu, Bin; Fang, Jin; Cao, Junci; Chen, Jie; Shu, Hang; Sheng, Long

2017-01-01

According to a high temperature superconducting (HTS) linear induction motor (LIM) designed for rail systems, the influence of electromagnetic parameters and mechanical structure parameters on the electromagnetic horizontal thrust, vertical force of HTS LIM and the maximum vertical magnetic field of HTS windings are analyzed. Through the research on the vertical field of HTS windings, the development regularity of the HTS LIM maximum input current with different stator frequency and different thickness value of the secondary conductive plate is obtained. The theoretical results are of great significance to analyze the stability of HTS LIM. Finally, based on theory analysis, HTS LIM test platform was built and the experiment was carried out with load. The experimental results show that the theoretical analysis is correct and reasonable. (paper)

Inkjet printable nanosilver suspensions for enhanced sintering quality in rapid manufacturing

International Nuclear Information System (INIS)

Bai, John G; Creehan, Kevin D; Kuhn, Howard A

2007-01-01

Inkjet printable nanosilver suspensions were prepared by dispersing 30 nm silver particles into a water-based binder system to enhance the sintering quality in rapid manufacturing. During three-dimensional printing (3DP), the nanosilver suspensions were inkjet printed onto repetitively spread microsilver powder for selective joining. Since the nanosilver particles in the suspensions can be sintered at relatively low temperatures to bond the neighbouring microsilver powder, they were used to provide the continuous bonding strength of the manufacturing parts during the heat-up procedure of the sintering operation. Comparative study shows that the silver parts printed using the nanosilver suspension were significantly enhanced in sintering quality than those printed using the binder system, especially when the silver parts had thin or small features with high aspect ratios

Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

2009-01-01

be the cause of the viscosity reduction. The flow behavior of alumina particles in water and BECy is markedly different. Aqueous alumina suspensions are shear thinning at all alumina loadings and capable of 50 vol% loading before losing fluidity whereas BECy/alumina suspensions show Newtonian behavior up to 5 vol%, and above 5 vol% show shear thinning at all shear rates. Highly loaded suspensions (i.e. 20vol% alumina) exhibit shear thinning at low and moderate shear rates and shear thickening at higher shear rates. The maximum particle loading for a fluid suspension, in this case, appears to be about 20 vol%. The difference in the viscosity of these suspensions must be related to the solvent-particle interactions for each system. The reason is not exactly known, but there are some notable differences between BECy and water. Water molecules are {approx}0.28 nm in length and highly hydrogen bonded with a low viscosity (1 mPa's) whereas in the cyanate ester (BECy) system, the solvent molecule is about 1.2 nm, in the largest dimension, with surfaces of varied charge distribution throughout the molecule. The viscosity of the monomer is also reasonably low for organic polymer precursor, about 7 mPa's. Nanoparticles in water tend to agglomerate and form flocs which are broken with the shear force applied during viscosity measurement. The particle-particle interaction is very important in this system. In BECy, the particles appear to be well dispersed and not as interactive. The solvent-particle interaction appears to be most important. It is not known exactly how the alumina particles interact with the monomer, but NMR suggests hydrogen bonding. These hydrogen bonds between the particle and monomer could very well affect the viscosity. A conclusion that can be reached in this work is that the presence of hydroxyl groups on the surface of the alumina particles is significant and seems to affect the interactions between other particles and the solvent. Thus, the

Development of a simulation model of semi-active suspension for monorail

Science.gov (United States)

Hasnan, K.; Didane, D. H.; Kamarudin, M. A.; Bakhsh, Qadir; Abdulmalik, R. E.

2016-11-01

The new Kuala Lumpur Monorail Fleet Expansion Project (KLMFEP) uses semiactive technology in its suspension system. It is recognized that the suspension system influences the ride quality. Thus, among the way to further improve the ride quality is by fine- tuning the semi-active suspension system on the new KL Monorail. The semi-active suspension for the monorail specifically in terms of improving ride quality could be exploited further. Hence a simulation model which will act as a platform to test the design of a complete suspension system particularly to investigate the ride comfort performance is required. MSC Adams software was considered as the tool to develop the simulation platform, where all parameters and data are represented by mathematical equations; whereas the new KL Monorail being the reference model. In the simulation, the model went through step disturbance on the guideway for stability and ride comfort analysis. The model has shown positive results where the monorail is in stable condition as an outcome from stability analysis. The model also scores a Rating 1 classification in ISO 2631 Ride Comfort performance which is very comfortable as an overall outcome from ride comfort analysis. The model is also adjustable, flexibile and understandable by the engineers within the field for the purpose of further development.

Robustness analysis of bogie suspension components Pareto optimised values

Science.gov (United States)

Mousavi Bideleh, Seyed Milad

2017-08-01

Bogie suspension system of high speed trains can significantly affect vehicle performance. Multiobjective optimisation problems are often formulated and solved to find the Pareto optimised values of the suspension components and improve cost efficiency in railway operations from different perspectives. Uncertainties in the design parameters of suspension system can negatively influence the dynamics behaviour of railway vehicles. In this regard, robustness analysis of a bogie dynamics response with respect to uncertainties in the suspension design parameters is considered. A one-car railway vehicle model with 50 degrees of freedom and wear/comfort Pareto optimised values of bogie suspension components is chosen for the analysis. Longitudinal and lateral primary stiffnesses, longitudinal and vertical secondary stiffnesses, as well as yaw damping are considered as five design parameters. The effects of parameter uncertainties on wear, ride comfort, track shift force, stability, and risk of derailment are studied by varying the design parameters around their respective Pareto optimised values according to a lognormal distribution with different coefficient of variations (COVs). The robustness analysis is carried out based on the maximum entropy concept. The multiplicative dimensional reduction method is utilised to simplify the calculation of fractional moments and improve the computational efficiency. The results showed that the dynamics response of the vehicle with wear/comfort Pareto optimised values of bogie suspension is robust against uncertainties in the design parameters and the probability of failure is small for parameter uncertainties with COV up to 0.1.

All-optical modulation based on electromagnetically induced transparency

International Nuclear Information System (INIS)

Fountoulakis, Antonios; Terzis, Andreas F.; Paspalakis, Emmanuel

2010-01-01

We numerically investigate the implementation of all-optical absorption modulation of electromagnetic pulses by a medium that exhibits electromagnetically induced transparency. The quantum system is modelled as a three-level Λ-type system that interacts with two electromagnetic pulses, a probe pulse and a coupling pulse. The dynamics of the system is described by the coupled Maxwell-density matrix equations, and we explore the dependence of the optical modulation efficiency on the parameters of the system.

Structures, systems and methods for harvesting energy from electromagnetic radiation

Science.gov (United States)

Novack, Steven D [Idaho Falls, ID; Kotter, Dale K [Shelley, ID; Pinhero, Patrick J [Columbia, MO

2011-12-06

Methods, devices and systems for harvesting energy from electromagnetic radiation are provided including harvesting energy from electromagnetic radiation. In one embodiment, a device includes a substrate and one or more resonance elements disposed in or on the substrate. The resonance elements are configured to have a resonant frequency, for example, in at least one of the infrared, near-infrared and visible light spectra. A layer of conductive material may be disposed over a portion of the substrate to form a ground plane. An optical resonance gap or stand-off layer may be formed between the resonance elements and the ground plane. The optical resonance gap extends a distance between the resonance elements and the layer of conductive material approximately one-quarter wavelength of a wavelength of the at least one resonance element's resonant frequency. At least one energy transfer element may be associated with the at least one resonance element.

Geometric nonlinear analysis of self-anchored cable-stayed suspension bridges.

Science.gov (United States)

Hui-Li, Wang; Yan-Bin, Tan; Si-Feng, Qin; Zhe, Zhang

2013-01-01

Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

Geometric Nonlinear Analysis of Self-Anchored Cable-Stayed Suspension Bridges

Directory of Open Access Journals (Sweden)

Wang Hui-Li

2013-01-01

Full Text Available Geometric nonlinearity of self-anchored cable-stayed suspension bridges is studied in this paper. The repercussion of shrinkage and creep of concrete, rise-to-span ratio, and girder camber on the system is discussed. A self-anchored cable-stayed suspension bridge with a main span of 800 m is analyzed with linear theory, second-order theory, and nonlinear theory, respectively. In the condition of various rise-to-span ratios and girder cambers, the moments and displacements of both the girder and the pylon under live load are acquired. Based on the results it is derived that the second-order theory can be adopted to analyze a self-anchored cable-stayed suspension bridge with a main span of 800 m, and the error is less than 6%. The shrinkage and creep of concrete impose a conspicuous impact on the structure. And it outmatches suspension bridges for system stiffness. As the rise-to-span ratio increases, the axial forces of the main cable and the girder decline. The system stiffness rises with the girder camber being employed.

Krylov subspace method with communication avoiding technique for linear system obtained from electromagnetic analysis

International Nuclear Information System (INIS)

Ikuno, Soichiro; Chen, Gong; Yamamoto, Susumu; Itoh, Taku; Abe, Kuniyoshi; Nakamura, Hiroaki

2016-01-01

Krylov subspace method and the variable preconditioned Krylov subspace method with communication avoiding technique for a linear system obtained from electromagnetic analysis are numerically investigated. In the k−skip Krylov method, the inner product calculations are expanded by Krylov basis, and the inner product calculations are transformed to the scholar operations. k−skip CG method is applied for the inner-loop solver of Variable Preconditioned Krylov subspace methods, and the converged solution of electromagnetic problem is obtained using the method. (author)

Interactions between electromagnetic fields and matter

CERN Document Server

Steiner, Karl-Heinz

2013-01-01

Interactions between Electromagnetic Fields and Matter deals with the principles and methods that can amplify electromagnetic fields from very low levels of signals. This book discusses how electromagnetic fields can be produced, amplified, modulated, or rectified from very low levels to enable these for application in communication systems. This text also describes the properties of matter and some phenomenological considerations to the reactions of matter when an action of external fields results in a polarization of the particle system and changes the bonding forces existing in the matter.

Motion stability of high-speed maglev systems in consideration of aerodynamic effects: a study of a single magnetic suspension system

Science.gov (United States)

Wu, Han; Zeng, Xiao-Hui; Yu, Yang

2017-12-01

In this study, the intrinsic mechanism of aerodynamic effects on the motion stability of a high-speed maglev system was investigated. The concept of a critical speed for maglev vehicles considering the aerodynamic effect is proposed. The study was carried out based on a single magnetic suspension system, which is convenient for proposing relevant concepts and obtaining explicit expressions. This study shows that the motion stability of the suspension system is closely related to the vehicle speed when aerodynamic effects are considered. With increases of the vehicle speed, the stability behavior of the system changes. At a certain vehicle speed, the stability of the system reaches a critical state, followed by instability. The speed corresponding to the critical state is the critical speed. Analysis reveals that when the system reaches the critical state, it takes two forms, with two critical speeds, and thus two expressions for the critical speed are obtained. The conditions of the existence of the critical speed were determined, and the effects of the control parameters and the lift coefficient on the critical speed were analyzed by numerical analysis. The results show that the first critical speed appears when the aerodynamic force is upward, and the second critical speed appears when the aerodynamic force is downward. Moreover, both critical speeds decrease with the increase of the lift coefficient.

Feasibility Study of the Electromagnetic Damper for Cable Structures Using Real-Time Hybrid Simulation

Directory of Open Access Journals (Sweden)

Ho-Yeon Jung

2017-10-01

Full Text Available Cable structure is a major component of long-span bridges, such as cable-stayed and suspension bridges, and it transfers the main loads of bridges to the pylons. As these cable structures are exposed to continuous external loads, such as vehicle and wind loads, vibration control and continuous monitoring of the cable are required. In this study, an electromagnetic (EM damper was designed and fabricated for vibration control and monitoring of the cable structure. EM dampers, also called regenerative dampers, consist of permanent magnets and coils. The electromagnetic force due to the relative motion between the coil and the permanent magnet can be used to control the vibration of the structure. The electrical energy can be used as a power source for the monitoring system. The effects of the design parameters of the damper were numerically analyzed and the damper was fabricated. The characteristics of the damper were analyzed with various external load changes. Finally, the vibration-control and energy-harvesting performances of the cable structure were evaluated through a hybrid simulation. The vibration-control and energy-harvesting performances for various loads were analyzed and the applicability to the cable structure of the EM damper was evaluated.

Robust non-fragile finite-frequency H∞ static output-feedback control for active suspension systems

Science.gov (United States)

Wang, Gang; Chen, Changzheng; Yu, Shenbo

2017-07-01

This paper deals with the problem of non-fragile H∞ static output-feedback control of vehicle active suspension systems with finite-frequency constraint. The control objective is to improve ride comfort within the given frequency range and ensure the hard constraints in the time-domain. Moreover, in order to enhance the robustness of the controller, the control gain perturbation is also considered in controller synthesis. Firstly, a new non-fragile H∞ finite-frequency control condition is established by using generalized Kalman-Yakubovich-Popov (GKYP) lemma. Secondly, the static output-feedback control gain is directly derived by using a non-iteration algorithm. Different from the existing iteration LMI results, the static output-feedback design is simple and less conservative. Finally, the proposed control algorithm is applied to a quarter-car active suspension model with actuator dynamics, numerical results are made to show the effectiveness and merits of the proposed method.

Electromagnetic Compatibility (EMC) and Noise Background Testing for Double Chooz PMT System

International Nuclear Information System (INIS)

Cepero, J. R.; Encabo Fernandez, F. J.; Pepe, I.; Verdugo, A.

2009-01-01

The Double Chooz PMT system is a HV/signal splitter. In this report is presented an electromagnetic compatibility and background noise testing for the Double Chooz PMT system. It was possible to proceed the EMC testing on different grounding configurations of PMT splitter due to its special PCB design, endowed of jumping points and a metal box ground electrode. (Author)

Electromagnetic Compatibility (EMC) and Noise Background Testing for Double Chooz PMT System

Energy Technology Data Exchange (ETDEWEB)

Cepero, J. R.; Encabo Fernandez, F. J.; Pepe, I.; Verdugo, A.

2009-05-21

The Double Chooz PMT system is a HV/signal splitter. In this report is presented an electromagnetic compatibility and background noise testing for the Double Chooz PMT system. It was possible to proceed the EMC testing on different grounding configurations of PMT splitter due to its special PCB design, endowed of jumping points and a metal box ground electrode. (Author)

Investigating high-concentration monoclonal antibody powder suspension in nonaqueous suspension vehicles for subcutaneous injection.

Science.gov (United States)

Bowen, Mayumi; Armstrong, Nick; Maa, Yuh-Fun

2012-12-01

Developing high-concentration monoclonal antibody (mAb) liquid formulations for subcutaneous (s.c.) administration is challenging because increased viscosity makes injection difficult. To overcome this obstacle, we investigated a nonaqueous powder suspension approach. Three IgG1 mAbs were spray dried and suspended at different concentrations in Miglyol® 840, benzyl benzoate, or ethyl lactate. Suspensions were characterized for viscosity, particle size, and syringeability; physical stability was visually inspected. Suspensions generally outperformed liquid solutions for injectability despite higher viscosity at the same mAb concentrations. Powder formulations and properties had little effect on viscosity or injectability. Ethyl lactate suspensions had lowest viscosity (Miglyol® 840 improved overall performance in high mAb concentration suspensions. This study demonstrated the viability of high mAb concentration (>300 mg/mL) in suspension formulations for s.c. administration. Copyright © 2012 Wiley Periodicals, Inc.

Separation of Cadmium in Printing Industrial Liquid Waste by Electromagnetic Plating System

International Nuclear Information System (INIS)

Prayitno

2007-01-01

To prevent incidence of environmental contamination and its effect to society health and other mortal, poisonous and dangerous substance waste have to be managed peculiarly by minimizing or eliminating the nature of its danger. Various processing have been developed to degrade the waste rate for example sorption, flotation, flocculation, etc., but the yield of the degradation of metal rate can not fulfill permanent standard quality of liquid waste. Because of the reason explained before, its important to make a new breakthrough as one of final phase processing alternative named reductant electromagnetic plating. Waste to be degraded in this research is cadmium. In fact cadmium represent the foregain metal for human and is not require at all in human body for metabolism process. Though plenty of cadmium exploited, but during for centuries it caused the food poisoned because this metal insoluble in organic acid. Separation of cadmium rate with electromagnetic plating influenced by time process, concentration, current strength, and type of electrode plate. Result of research indicate that the optimum time processing if using plate of copper electrode is during 30 minute and using plate of aluminium electrode is during 20 minute. Optimum of strong current that used in process of electromagnetic plating is only 0.8 Ampere and concentration effective is 5 mg / L. The most effective type of electrode plate for reducing cadmium from waste by using electromagnetic plating is aluminium. Appliance of electromagnetic plating system is very compatible used for the reduction of cadmium and others metal for feed concentration (1 - 5) mg/L .at the price efficiency of reduction is (95 - 98) %, standard quality of liquid waste is (0.05 - 1) mg/L. (author)

Application of microwave cell system in calibration of electromagnetic field meters

International Nuclear Information System (INIS)

Abu-Kassem, I.

2012-11-01

The aim of this work is to improve radiation measurements of electromagnetic field (EMF) through realizing tests and calibrations of measurement devices by intercomparison within the microwaves (MW) range according to EMF wave cell properties. Actually, the calibration facility in electromagnetic field is not available in Syria; therefore, realizing an experimental system for electromagnetic field radiometer calibration is very important at national level. This study showed the possibility of using EMF wave cell in intercomparison of electromagnetic field radiometers in order to achieve a direct calibration via standard radiometer. The EMF wave cell properties were studied and the homogeneity of its EMF was tested using the EF Cube probe. Results showed that the field homogeneity inside the cell is good and the variation of electric field strength, within the comparison position, is less than 10% of measured values. It was recognized that the probe form and dimensions influence the comparison results; and measurement results showed that it's possible to achieve comparison in the working domain of EMF wave cell (10 - 3000 MHz) with a relative deviation of result values between 10% and 30% according to the measurement device and frequency range. Development of comparison process in order to obtain accurate results needs to improve mechanical supports of tested probes and to introduce a correction factor related to studied probe form and dimensions. From another side, it is better to carry out measurements at frequencies around the central frequency, and not close to frequency range borders, of the EMF wave cell working frequency domain. (author)

Characteristic parameters of electromagnetic signals from a human heart system

International Nuclear Information System (INIS)

Liu Xin-Yuan; Wang Yin; Zhang Su-Ming; Gao Hong-Lei; Pei Liu-Qing; Dai Yuan-Dong

2011-01-01

The electromagnetic field of a human heart system is a bioelectromagnetic field. Electrocardiography (ECG) and magnetocardiography (MCG) are both carriers of electromagnetic information about the cardiac system, and they are nonstationary signals. In this study, ECG and MCG data from healthy subjects are acquired; the MCG data are captured using a high-T c radio frequency superconducting quantum interference device (HTc rf SQUIDs) and the QRS complexes in these data are analysed by the evolutionary spectrum analysis method. The results show that the quality factor Q and the central frequency f z of the QRS complex evolutionary spectrum are the characteristic parameters (CHPs) of ECG and MCG in the time—frequency domain. The confidence intervals of the mean values of the CHPs are estimated by the Student t distribution method in mathematical statistics. We believe that there are threshold ranges of the mean values of Q and f z for healthy subjects. We have postulated the following criterion: if the mean values of CHPs are in the proper ranges, the cardiac system is in a normal condition and it possesses the capability of homeostasis. In contrast, if the mean values of the CHPs do not lie in the proper ranges, the homeostasis of the cardiac system is lacking and some cardiac disease may follow. The results and procedure of MCG CHPs in the study afford a technological route for the application of HTc rf SQUIDs in cardiology. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Suspension trauma; Le traumatisme de suspension

Energy Technology Data Exchange (ETDEWEB)

Trudel, S. [Le Centre de sante et de services sociaux du rocher Perce, Chandler, PQ (Canada)

2010-07-01

This presentation discussed the precautions that should be taken to avoid falls from wind turbines or transmission towers. Suspension trauma was explained by a medical doctor in terms of physiology and the body's normal circulation and the elements that disturb normal physiology when in suspension. The trauma occurs following a fall, which carries the risk of 1or more disorders, such as massive hemorrhage, high cardiac pulse, and constriction of blood vessels. Nausea, vertigo, cardiac arrhythmia and sweating occur 15 to 20 minutes following the fall. The presentation emphasized the importance of having qualified personnel at the site and wearing proper harnesses and equipment that supports the neck. figs.

Liquid crystalline phases in suspensions of pigments in non-polar solvents

Science.gov (United States)

Klein, Susanne; Richardson, Robert M.; Eremin, Alexey

We will discuss colloid suspensions of pigments and compare their electro-optic properties with those of traditional dyed low molecular weight liquid crystal systems. There are several potential advantages of colloidal suspensions over low molecular weight liquid crystal systems: a very high contrast because of the high orientational order parameter of suspensions of rod shaped nano-particles, the excellent light fastness of pigments as compared to dyes and high colour saturations resulting from the high loading of the colour stuff. Although a weak `single-particle' electro-optic response can be observed in dilute suspensions, the response is very much enhanced when the concentration of the particles is sufficient to lead to a nematic phase. Excellent stability of suspensions is beneficial for experimental observation and reproducibility, but it is a fundamental necessity for display applications. We therefore discuss a method to achieve long term stability of dispersed pigments and the reasons for its success. Small angle X-ray scattering was used to determine the orientational order parameter of the suspensions as a function of concentration and the dynamic response to an applied electric field. Optical properties were investigated for a wide range of pigment concentrations. Electro-optical phenomena, such as field-induced birefringence and switching, were characterised. In addition, mixtures of pigment suspensions with small amounts of ferrofluids show promise as future magneto-optical materials.

5 MJ flywheel based on bulk HTS magnetic suspension

Science.gov (United States)

Poltavets, V.; Kovalev, K.; Ilyasov, R.; Glazunov, A.; Maevsky, V.; Verzbitsky, L.; Akhmadyshev, V.; Shikov, A.

2014-05-01

Nowadays the flywheel energy storage systems (FES) are developed intensively as uninterruptible power supply (UPS) devices for on-land and transport (especially airborne) applications worldwide. This work is devoted to the FES with magnetic suspension on the base of bulk HTS YBCO elements and permanent magnets. The developed FES is intended to be used as UPS in Russian atomic industry in case of an emergency. For the successful design of the FES the following questions should be solved: design of the motor/generator, design of the rotor (flywheel), design of the bearing system, design of the control system and system of power load matching, design of the cooling system. The developed small-scale FES with the stored energy 0.5 MJ was used to solve these basic questions. The elaborated FES consists of the synchronous electric machine with permanent magnets, the solid flywheel with axial magnetic suspension on the base of YBCO bulks and permanent magnets, the system of control and power load matching, and the system of liquid nitrogen cooling. The results of theoretical modeling of different schematics of magnetic suspension and experimental investigations of the constructed FES are presented. The design of the future full-scale FES with the stored energy ~5 MJ and output power up to 100 kW is described. The test results of the flywheel rotor and HTS magnetic suspension of 5 MJ FES are presented. This work is done under support of Rosatom within the frames of Russian Project "Superconducting Industry"

Adaptive magnetorheological seat suspension for the expeditionary fighting vehicle

International Nuclear Information System (INIS)

Hiemenz, G J; Hu, W; Wereley, N M

2009-01-01

The Expeditionary Fighting Vehicle (EFV) is an amphibious vehicle designed to operate through harsh conditions and at much higher speeds than its predecessors. These unique capabilities and broadly varying operational conditions lead to a complex design and human factors scenario for the forward seating positions that cannot be solved using conventional passive seat suspension systems. Injurious shock loads transmitted to the occupants when traversing over water in high sea states and/or at high speeds, as well as harmful shock and vibration transmitted to the occupants when the vehicle is travelling over land, pose a threat to occupant health and significantly limit mission duration. In this study, a semi-active magnetorheological (MR) seat suspension is developed which adapts to broadly varying operational conditions, as well as occupant weight, to provide optimal protection of EFV occupants. It is shown that this MR seat suspension system will reduce the shock and vibration transmitted to the occupant by up to 33% and 65%, respectively, as compared to the existing passive suspension.

Adaptive magnetorheological seat suspension for the expeditionary fighting vehicle

Energy Technology Data Exchange (ETDEWEB)

Hiemenz, G J [Techno-Sciences, Inc., 11750 Beltsville Dr. Ste. 300, Beltsville, MD 20705 (United States); Hu, W; Wereley, N M [Aerospace Engineering, University of Maryland, College Park, MD 20712 (United States)], E-mail: greg@technosci.com, E-mail: wereley@umd.edu

2009-02-01

The Expeditionary Fighting Vehicle (EFV) is an amphibious vehicle designed to operate through harsh conditions and at much higher speeds than its predecessors. These unique capabilities and broadly varying operational conditions lead to a complex design and human factors scenario for the forward seating positions that cannot be solved using conventional passive seat suspension systems. Injurious shock loads transmitted to the occupants when traversing over water in high sea states and/or at high speeds, as well as harmful shock and vibration transmitted to the occupants when the vehicle is travelling over land, pose a threat to occupant health and significantly limit mission duration. In this study, a semi-active magnetorheological (MR) seat suspension is developed which adapts to broadly varying operational conditions, as well as occupant weight, to provide optimal protection of EFV occupants. It is shown that this MR seat suspension system will reduce the shock and vibration transmitted to the occupant by up to 33% and 65%, respectively, as compared to the existing passive suspension.

Covariant electromagnetic field lines

Science.gov (United States)

Hadad, Y.; Cohen, E.; Kaminer, I.; Elitzur, A. C.

2017-08-01

Faraday introduced electric field lines as a powerful tool for understanding the electric force, and these field lines are still used today in classrooms and textbooks teaching the basics of electromagnetism within the electrostatic limit. However, despite attempts at generalizing this concept beyond the electrostatic limit, such a fully relativistic field line theory still appears to be missing. In this work, we propose such a theory and define covariant electromagnetic field lines that naturally extend electric field lines to relativistic systems and general electromagnetic fields. We derive a closed-form formula for the field lines curvature in the vicinity of a charge, and show that it is related to the world line of the charge. This demonstrates how the kinematics of a charge can be derived from the geometry of the electromagnetic field lines. Such a theory may also provide new tools in modeling and analyzing electromagnetic phenomena, and may entail new insights regarding long-standing problems such as radiation-reaction and self-force. In particular, the electromagnetic field lines curvature has the attractive property of being non-singular everywhere, thus eliminating all self-field singularities without using renormalization techniques.

Electromagnetic aquametry electromagnetic wave interaction with water and moist substances

CERN Document Server

Kupfer, Klaus

2006-01-01

This book covers all aspects of Electromagnetic Aquametry. It summarizes the wide area of metrology and its applications in electromagnetic sensing of moist materials. The physical properties of water in various degrees of binding interacting with electromagnetic fields is presented by model systems. The book describes measurement methods and sensors in the frequency domain, TDR-techniques for environmental problems, methods and sensors for quality assessment of biological substances, and nuclear magnetic resonance techniques. Environmental sciences, as well as civil and geoengineering, fossil fuels, food and pharmaceutical science are the main fields of application. A very wide frequency sprectrum is used for dielectric measurement methods, but the microwave range is clearly dominant. Multiparameter methods as well as methods of principal components and artificial neural networks for density independent measurements are described.

Nuclear structure investigations with electromagnetic probes

International Nuclear Information System (INIS)

Drechsel, D.

1987-01-01

This paper is related to the study of electromagnetic interactions, current of hadronic systems, deep inelastic scattering, quasifree scattering, low energy theorems and electromagnetic reactions above pion threshold. (A.C.A.S.) [pt

Weakly sheared active suspensions: hydrodynamics, stability, and rheology.

Science.gov (United States)

Cui, Zhenlu

2011-03-01

We present a kinetic model for flowing active suspensions and analyze the behavior of a suspension subjected to a weak steady shear. Asymptotic solutions are sought in Deborah number expansions. At the leading order, we explore the steady states and perform their stability analysis. We predict the rheology of active systems including an activity thickening or thinning behavior of the apparent viscosity and a negative apparent viscosity depending on the particle type, flow alignment, and the anchoring conditions, which can be tested on bacterial suspensions. We find remarkable dualities that show that flow-aligning rodlike contractile (extensile) particles are dynamically and rheologically equivalent to flow-aligning discoid extensile (contractile) particles for both tangential and homeotropic anchoring conditions. Another key prediction of this work is the role of the concentration of active suspensions in controlling the rheological behavior: the apparent viscosity may decrease with the increase of the concentration.

Coupling Mechanism and Decoupled Suspension Control Model of a Half Car

Directory of Open Access Journals (Sweden)

Hailong Zhang

2016-01-01

Full Text Available A structure decoupling control strategy of half-car suspension is proposed to fully decouple the system into independent front and rear quarter-car suspensions in this paper. The coupling mechanism of half-car suspension is firstly revealed and formulated with coupled damping force (CDF in a linear function. Moreover, a novel dual dampers-based controllable quarter-car suspension structure is proposed to realize the independent control of pitch and vertical motions of the half car, in which a newly added controllable damper is suggested to be installed between the lower control arm and connection rod in conventional quarter-car suspension structure. The suggested damper constantly regulates the half-car pitch motion posture in a smooth and steady operation condition meantime achieving the expected completely structure decoupled control of the half-car suspension, by compensating the evolved CDF.

Broadband electromagnetic environments simulator (EMES)

International Nuclear Information System (INIS)

Pollard, N.

1977-01-01

A new test facility has been developed by Sandia Laboratories for determining the effects of electromagnetic environments on systems and components. The facility is capable of producing uniform, vertically polarized, continuous wave (CW) and pulsed fields over the frequency range of dc to 10 GHz. This broadband capability addresses the electromagnetic radiation (EMR) threat and is ideally suited to computer controlled sweeping and data acquisition. EMES is also capable of producing uniform transient fields having the wave shape and magnitude characteristic of a nuclear electromagnetic pulse (EMP) and near lightning. The design consists of a truncated, triplate, rectangular coaxial transmission line. The spacing between the flat center conductor and the ground planes is 4 meters. The line is terminated in its characteristic impedance of 50 ohms. At frequencies below the first resonance of the facility it behaves as a typical coaxial system. Above resonance, a wall of electromagnetic absorbing material provides a nonreflecting termination. Thus, EMES essentially combines the elements of a transmission line and an anechoic chamber. It will not radiate electromagnetic energy into the surrounding area because it is a shielded transmission line

Vibration Energy Harvesting on Vehicle Suspension Using Rotary and Linear Electromagnetic Generator

Directory of Open Access Journals (Sweden)

Arif Indro Sultoni

2013-04-01

Full Text Available In this paper, we discuss comparation of vehicle vibration energy harvesting between rotary and linear electromagnetic generator. We construct the two model of energy harvester mechanism and then analyze both of energy absorbtion and vehicle comfortability. Furthermore, we analyze both of energy absorbtion and vehicle comfortability. Vehicle is modeled as quarter car. Rotarty generator harvests 2.5 x 10-4 Watt. The other hand, linear generator has viscous characteristic and capable to generates 90 Watts with 12 Volt power supply for 0.03 m amplitude of bumpy road input. Linear generator reduces oscillation with 1.2 sec settling time. It is more comfort than the angular which has 3 sec in settling time. With unnevenees road input, mean power of this generator is 64 Watt.

Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

Energy Technology Data Exchange (ETDEWEB)

Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

1983-02-01

This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants.

Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

International Nuclear Information System (INIS)

Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

1983-02-01

This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants

A microwave window for K band electromagnetic systems

DEFF Research Database (Denmark)

Rybalko, Oleksandr

2017-01-01

This article proposes a solution for microwave window at K band. Properties of the window such as performance (transparency) at microwave frequencies, dimensions, and mounting place are discussed. The dimensions of the window were optimized in a full-wave simulator. To verify the design...... and simulation results the prototype of the window is realized by implementing into transition section and tested experimentally. The microwave window provides low return loss |S11| below −30 dB, low insertion loss |S21| below −0.5 dB and can be used for electromagnetic systems where vacuum sealing is required...

Progress of Maglev-linear vehicles in the Federal Republic of Germany

Energy Technology Data Exchange (ETDEWEB)

Hartmann, P

1988-04-01

This paper describes a research and development programme on the technology of track-guided transport systems. The delimitation of the operational ranges between advanced wheel-on-rail systems and the electromagnetic suspension system and the development history of the magnetic suspension system, both state of the work and future developments are discussed.

ELASTO-KINEMATIC COMPUTATIONAL MODEL OF SUSPENSION WITH FLEXIBLE SUPPORTING ELEMENTS

Directory of Open Access Journals (Sweden)

Tomáš Vrána

2016-04-01

Full Text Available This paper analyzes the impact of flexibility of individual supporting elements of independent suspension on its elasto-kinematic characteristics. The toe and camber angle are the geometric parameters of the suspension, which waveforms and their changes under the action of vertical, longitudinal and transverse forces affect the stability of the vehicle. To study these dependencies, the computational multibody system (MBS model of axle suspension in the system HyperWorks is created. There are implemented Finite-Element-Method (FEM models reflecting the flexibility of the main supporting elements. These are subframe, the longitudinal arms, transverse arms and knuckle. Flexible models are developed using Component Mode Synthesis (CMS by Craig-Bampton. The model further comprises force elements, such as helical springs, shock absorbers with a stop of the wheel and the anti-roll bar. Rubber-metal bushings are modeled flexibly, using nonlinear deformation characteristics. Simulation results are validated by experimental measurements of geometric parameters of real suspension.

A magneto rheological hybrid damper for railway vehicles suspensions

Directory of Open Access Journals (Sweden)

Gheorghe GHITA

2012-09-01

Full Text Available High speed railway vehicles features a specific lateral oscillation resulting from the coupled lateral displacement and yaw of the wheelset which leads to a sinusoid movement of the wheelset along the track, transferred to the entire vehicle. The amplitude of this oscillation is strongly dependant on vehicle’s velocity. Over a certain value, namely the critical speed, the instability phenomenon so-called hunting occurs. To raise the vehicle’s critical speed different designs of the suspension all leading to a much stiffer vehicle can be envisaged. Different simulations prove that a stiffer central suspension will decrease the passenger’s comfort in terms of lateral accelerations of the carboy. The authors propose a semi-active magneto rheological suspension to improve the vehicle’s comfort at high speeds. The suspension has as executive elements hybrid magneto rheological dampers operating under sequential control strategy type balance logic. Using an original mathematical model for the lateral dynamics of the vehicle the responses of the system with passive and semi-active suspensions are simulated. It is shown that the semi-active suspension can improve the vehicle performances.

Electromagnetic compatibility of nuclear power plants

International Nuclear Information System (INIS)

Cabayan, H.S.

1983-01-01

Lately, there has been a mounting concern about the electromagnetic compatibility of nuclear-power-plant systems mainly because of the effects due to the nuclear electromagnetic pulse, and also because of the introduction of more-sophisticated and, therefore, more-susceptible solid-state devices into the plants. Questions have been raised about the adequacy of solid-state-device protection against plant electromagnetic-interference sources and transients due to the nuclear electromagnetic pulse. In this paper, the author briefly reviews the environment, and the coupling, susceptibility, and vulnerability assessment issues of commercial nuclear power plants

Fiducial-Based Translational Localization Accuracy of Electromagnetic Tracking System and On-Board Kilovoltage Imaging System

International Nuclear Information System (INIS)

Santanam, Lakshmi; Malinowski, Kathleen; Hubenshmidt, James; Dimmer, Steve; Mayse, Martin L.; Bradley, Jeffrey; Chaudhari, Amir; Lechleiter, Kirsten; Goddu, Sree Krishna Murty; Esthappan, Jacqueline; Mutic, Sasa; Low, Daniel A.; Parikh, Parag

2008-01-01

Purpose: The Calypso medical four-dimensional localization system uses AC electromagnetics, which do not require ionizing radiation, for accurate, real-time tumor tracking. This investigation compared the static and dynamic tracking accuracy of this system to that of an on-board imaging kilovoltage X-ray system for concurrent use of the two systems. Methods and Materials: The localization accuracies of a kilovoltage imaging system and a continuous electromagnetic tracking system were compared. Using an in-house developed four-dimensional stage, quality-assurance fixture containing three radiofrequency transponders was positioned at a series of static locations and then moved through the ellipsoidal and nonuniform continuous paths. The transponder positions were tracked concurrently by the Calypso system. For static localization, the transponders were localized using portal images and digitally reconstructed radiographs by commercial matching software. For dynamic localization, the transponders were fluoroscopically imaged, and their positions were determined retrospectively using custom-written image processing programs. The localization data sets were synchronized with and compared to the known quality assurance fixture positions. The experiment was repeated to retrospectively track three transponders implanted in a canine lung. Results: The root mean square error of the on-board imaging and Calypso systems was 0.1 cm and 0.0 cm, respectively, for static localization, 0.22 mm and 0.33 mm for dynamic phantom positioning, and 0.42 mm for the canine study. Conclusion: The results showed that both localization systems provide submillimeter accuracy. The Calypso and on-board imaging tracking systems offer distinct sets of advantages and, given their compatibility, patients could benefit from the complementary nature of the two systems when used concurrently

Suspension, a Wake-Up Call: Rural Educators' Attitudes toward Suspension.

Science.gov (United States)

Henderson, Joan; Friedland, Billie

Data from the West Virginia Department of Education reveals that from September 1991 to January 1992, school districts reported 18,915 out-of-school suspensions involving 12,997 students. In 1995, the West Virginia State Legislature enacted the Safe Schools Act, which specifically mandates suspension for no less than 12 consecutive months for…

Electromagnetic forces on type-II superconducting rotating cylinders

International Nuclear Information System (INIS)

Saif, A.G.; Refai, T.F.; El-Sabagh, M.A.

1995-01-01

Analytical solutions of the electromagnetic fields are presented for a system composed of an infinitely long superconducting cylinder rotating about its axis and placed parallel to two infinitely long normal conducting wires. Both wires carry the same alternating current. From the obtained electromagnetic fields the electromagnetic power loss on the cylinder surface, electromagnetic forces due to induced currents, electromagnetic torque, and the work opposing the rotation of the cylinder are calculated. (orig.)

Qualification criteria verification for aisi-4340 steel suspension lug

International Nuclear Information System (INIS)

Riaz, M.A.; Alam, M.

2005-01-01

All external loads carried underneath an aircraft are mounted onto it through mechanism generally known as suspension system. The externally mounted attachments like bombs, missiles and fuel tanks etc. experience enormous aerodynamic and inertial forces in the flights. These forces are transferred to the interface point of suspension system, known as 'Suspension Lug'. Thus lugs are considered critical component and have extremely stringent qualification criteria standards used in the aviation industry in USA, Europe, Russia, etc. Different standards prevail in different parts of the world about qualification and testing of these lugs. As Pakistan is entering into aviation industry, therefore there is a need to fulfill the requirements of these standards, to suit Pakistani environment. The suspension lug under study is 2000 Ibs. load class made from AISI-4340 Steel having good mechanical properties as per required standard. The manufacturing processes included forging, machining and vacuum heat treatment. The prototypes of suspension lugs were manufactured in the local industry and subjected to the required mechanical tests such as tensile testing at 5 to 35 degree angles. Impact testing at cryogenic temperatures of -50 to -70 degree C, and breaking load testing were performed. The acceptable results were obtained and mechanical testing for qualification of lugs was finalized and standardized. The options were compared with practical viability, utilization of product and cost effectiveness. (author)

Load-cell based characterization system for a “Violin-Mode” shadow-sensor in advanced LIGO suspensions

Energy Technology Data Exchange (ETDEWEB)

Lockerbie, N. A.; Tokmakov, K. V. [SUPA (Scottish Universities Physics Alliance) Department of Physics, University of Strathclyde, 107 Rottenrow, Glasgow G4 0NG (United Kingdom)

2016-07-15

The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre’s holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

Load-cell based characterization system for a “Violin-Mode” shadow-sensor in advanced LIGO suspensions

International Nuclear Information System (INIS)

Lockerbie, N. A.; Tokmakov, K. V.

2016-01-01

The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre’s holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

Electromagnetic topology: Characterization of internal electromagnetic coupling

Science.gov (United States)

Parmantier, J. P.; Aparicio, J. P.; Faure, F.

1991-01-01

The main principles are presented of a method dealing with the resolution of electromagnetic internal problems: Electromagnetic Topology. A very interesting way is to generalize the multiconductor transmission line network theory to the basic equation of the Electromagnetic Topology: the BLT equation. This generalization is illustrated by the treatment of an aperture as a four port junction. Analytical and experimental derivations of the scattering parameters are presented. These concepts are used to study the electromagnetic coupling in a scale model of an aircraft, and can be seen as a convenient means to test internal electromagnetic interference.

Evaluation of electromagnetic interference environment of the instrumentation and control systems in nuclear power units

Energy Technology Data Exchange (ETDEWEB)

Min, Moon-Gi; Lee, Jae-Ki; Ji, Yeong-Haw; Jo, Sung-Han [Korea Hydro & Nuclear Power Co., Ltd., 1312-70 Yuesong-daero, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Kim, Hee-Je, E-mail: heeje@pusan.ac.kr [Pusan National University, 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, Busan 609-735 (Korea, Republic of)

2015-04-15

Highlights: • We surveyed the electromagnetic emissions at the location of I&C systems. • We assessed the electromagnetic levels on reactor types from thirteen nuclear plants. • We evaluated the margin between plant emission limits and the highest composite levels. • We presented the formula of radiated susceptibility test levels to non-safety-related I&C systems. - Abstract: The electromagnetic interference (EMI) generated from sources in power units can interfere with digital Instrument and Control (I&C) systems. When EMI is emitted with conducted and radiated noise, it interferes with the signals of the I&C systems. Since the digital I&C systems are efficient and competitively priced, the analogue I&C systems have been upgraded and replaced with digital I&C systems, but these systems have less EMI immunity. When safety-related I&C systems are installed in the units, the verification of equipment EMI should not be done in site-specific tests but in test facilities. There are needs to do the overall site-specific EMI assessment of I&C systems depending on the reactor types from thirteen operating units. This study evaluated the margin between plant emission limits and the highest composite plant emissions of the EMI. When the non-safety-related I&C equipment or systems are placed in the units, there are no individual test levels of the radiated electrical field. If need be, the level should comply with the test levels of the radiated electrical field on the safety-related I&C systems. This paper presents the test levels of radiated electrical fields to non-safety-related I&C equipment or systems.

Simulation Research on Vehicle Active Suspension Controller Based on G1 Method

Science.gov (United States)

Li, Gen; Li, Hang; Zhang, Shuaiyang; Luo, Qiuhui

2017-09-01

Based on the order relation analysis method (G1 method), the optimal linear controller of vehicle active suspension is designed. The system of the main and passive suspension of the single wheel vehicle is modeled and the system input signal model is determined. Secondly, the system motion state space equation is established by the kinetic knowledge and the optimal linear controller design is completed with the optimal control theory. The weighting coefficient of the performance index coefficients of the main passive suspension is determined by the relational analysis method. Finally, the model is simulated in Simulink. The simulation results show that: the optimal weight value is determined by using the sequence relation analysis method under the condition of given road conditions, and the vehicle acceleration, suspension stroke and tire motion displacement are optimized to improve the comprehensive performance of the vehicle, and the active control is controlled within the requirements.

Electromagnetic reverberation chambers

CERN Document Server

Besnier, Philippe

2013-01-01

Dedicated to a complete presentation on all aspects of reverberation chambers, this book provides the physical principles behind these test systems in a very progressive manner. The detailed panorama of parameters governing the operation of electromagnetic reverberation chambers details various applications such as radiated immunity, emissivity, and shielding efficiency experiments.In addition, the reader is provided with the elements of electromagnetic theory and statistics required to take full advantage of the basic operational rules of reverberation chambers, including calibration proc

Requirements and analysis of electromagnetic compatibility of safety-related instrumentation and control system in nuclear power plants

International Nuclear Information System (INIS)

Liu Sujuan

2002-01-01

The state-of-the-art instrumentation and control system and the influence of their application to the electromagnetic compatibility is analyzed. Based on the present situation of nuclear safety in China and relevant experiences from other countries, the author tries to probe into the requirements and test methods about how safety-related instrument and control system to accommodate electromagnetic interference, radio-frequency interference and power surges in the environments of nuclear power plant so as to develop Chinese safety standards

A portable high-efficiency electromagnetic energy harvesting system using supercapacitors for renewable energy applications in railroads

International Nuclear Information System (INIS)

Zhang, Xingtian; Zhang, Zutao; Pan, Hongye; Salman, Waleed; Yuan, Yanping; Liu, Yujie

2016-01-01

Graphical abstract: In this study, we develop a portable high-efficiency electromagnetic energy harvesting system with supercapacitors that converts the energy of track vibrations into electricity. The generated electricity is stored in the supercapacitors and used in remote areas for safety facilities or in standby power supplies for rail-side equipment. The proposed system consists of a mechanical transmission and a rectifier. Acting as the energy input and transmission, Gears and a rack amplify the small vibrations of the track, and one-way bearings enhance efficiency by transforming bidirectional motion to unidirectional rotation. Supercapacitors are used in the energy harvesting system for the first time. The supercapacitors permit the storage of energy from rapidly changing transient currents and a steady power supply for external loads. The proposed system is demonstrated through dynamic simulations, which show the rapid response of the system. An efficiency of 55.5% is demonstrated in bench tests, verifying that the proposed electromagnetic energy harvesting system is effective and practical in renewable energy applications for railroads. - Highlights: • A frequently ignored source of energy, railroad track vibrations, is harvested. • A novel conversion mechanism is designed to maximize efficiency. • Supercapacitors are included in the electromagnetic energy harvesting system. • A portable design is proposed for wider application. - Abstract: As the demand for alternative sources of energy has increased, harvesting abundant environmental energy such as vibration energy including track vibrations in railway systems has attracted greater attention. In this study, we develop a portable high-efficiency electromagnetic energy harvesting system with supercapacitors that converts the energy of track vibrations into electricity. The generated electricity is stored in the supercapacitors and used in remote areas for safety facilities or in standby power

Discriminating electromagnetic radiation based on angle of incidence

Science.gov (United States)

Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.

2015-06-16

The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.

Wheeled Vehicle Drive Lines, Axles, and Suspension Systems. Military Curriculum Materials for Vocational and Technical Education.

Science.gov (United States)

Army Ordnance Center and School, Aberdeen Proving Ground, MD.

This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle drive lines, axles, and suspension systems. It provides the basic…

An efficient sensitivity analysis method for modified geometry of Macpherson suspension based on Pearson correlation coefficient

Science.gov (United States)

Shojaeefard, Mohammad Hasan; Khalkhali, Abolfazl; Yarmohammadisatri, Sadegh

2017-06-01

The main purpose of this paper is to propose a new method for designing Macpherson suspension, based on the Sobol indices in terms of Pearson correlation which determines the importance of each member on the behaviour of vehicle suspension. The formulation of dynamic analysis of Macpherson suspension system is developed using the suspension members as the modified links in order to achieve the desired kinematic behaviour. The mechanical system is replaced with an equivalent constrained links and then kinematic laws are utilised to obtain a new modified geometry of Macpherson suspension. The equivalent mechanism of Macpherson suspension increased the speed of analysis and reduced its complexity. The ADAMS/CAR software is utilised to simulate a full vehicle, Renault Logan car, in order to analyse the accuracy of modified geometry model. An experimental 4-poster test rig is considered for validating both ADAMS/CAR simulation and analytical geometry model. Pearson correlation coefficient is applied to analyse the sensitivity of each suspension member according to vehicle objective functions such as sprung mass acceleration, etc. Besides this matter, the estimation of Pearson correlation coefficient between variables is analysed in this method. It is understood that the Pearson correlation coefficient is an efficient method for analysing the vehicle suspension which leads to a better design of Macpherson suspension system.

The Electromechanical Low-Power Active Suspension: Modeling, Control, and Prototype Testing

NARCIS (Netherlands)

Evers, W.J.E.; Teerhuis, A.P.; Knaap, van der A.C.M.; Besselink, I.J.M.; Nijmeijer, H.

2011-01-01

The high energy consumption of market-ready active suspension systems is the limiting factor in the competition with semi-active devices. The variable geometry active suspension is an alternative with a significantly lower power consumption. However, previous designs suffer from packaging problems,

The electromechanical low-power active suspension: modeling, control, and prototype testing

NARCIS (Netherlands)

Evers, W.J.; Teerhuis, A.P.; Knaap, A. van der; Besselink, I.; Nijmeijer, H.

2011-01-01

The high energy consumption of market-ready active suspension systems is the limiting factor in the competition with semi-active devices. The variable geometry active suspension is an alternative with a significantly lower power consumption. However, previous designs suffer from packaging problems,

Structural observation of long-span suspension bridges for safety assessment: implementation of an optical displacement measurement system

International Nuclear Information System (INIS)

Martins, L Lages; Ribeiro, A Silva; Rebordão, J M

2015-01-01

This paper addresses the implementation of an optical displacement measurement system in the observation scenario of a long-span suspension bridge and its contribution for structural safety assessment. The metrological background required for quality assurance of the measurements is described, namely, the system's intrinsic parameterization and integration in the SI dimensional traceability chain by calibration, including its measurement uncertainty assessment

[National system of protection against electromagnetic fields 0 Hz-300 GHz in the light of current legal regulations].

Science.gov (United States)

Aniołczyk, Halina

2006-01-01

Exposure to electromagnetic fields (EMF) occurs when man is exposed to the effect of electric, magnetic and electromagnetic fields and contact currents different from those resulting from physiological processes in the organism or other natural phenomena. In Poland, the system of protection against EMF has been functioning for over 35 years. In 2001, when the Minister of Labor and Social Policy issued the regulation introducing the maximum admissible intensities (MAI) for electromagnetic fields and radiation within the range of 0 Hz-300 GHz, the system was directed mainly towards evaluation of exposure to EMF occurring in the occupational environment. The system is linked via MAI values with human protection in the natural environment. In this paper, the background, principles and the range of the national system of protection against EMF and its monitoring are presented. The project of implementation of EU directives, following Poland's accession to the European Union is also discussed.

Controllable damping of high-Q violin modes in fused silica suspension fibers

Science.gov (United States)

Dmitriev, A. V.; Mescheriakov, S. D.; Tokmakov, K. V.; Mitrofanov, V. P.

2010-01-01

Fused silica fiber suspension of the test masses will be used in the interferometric gravitational wave detectors of the next generation. This allows a significant reduction of losses in the suspension and thermal noise associated with the suspension. Unfortunately, unwanted violin modes may be accidentally excited in the suspension fibers. The Q-factor of the violin modes also exceeds 108. They have a ring-down time that is too long and may complicate the stable control of the interferometer. Results of the investigation of a violin mode active damping system are described. An original sensor and actuator were especially developed to realize the effective coupling of a thin, optically transparent, non-conducting fused silica fiber with an electric circuit. The damping system allowed the changing of the violin mode's damping rate over a wide range.

Chain Dynamics in Magnetorheological Suspensions

Science.gov (United States)

Gast, A. P.; Furst, E. M.

1999-01-01

Magnetorheological (MR) suspensions are composed of colloidal particles which acquire dipole moments when subjected to an external magnetic field. At sufficient field strengths and concentrations, the dipolar particles rapidly aggregate to form long chains. Subsequent lateral cross-linking of the dipolar chains is responsible for a rapid liquid-to-solid-like rheological transition. The unique, magnetically-activated rheological properties of MR suspensions make them ideal for interfacing mechanical systems to electronic controls. Additionally, the ability to experimentally probe colloidal suspensions interacting through tunable anisotropic potentials is of fundamental interest. Our current experimental work has focused on understanding the fluctuations of dipolar chains. It has been proposed by Halsey and Toor (HT) that the strong Landau-Peierls thermal fluctuations of dipolar chains could be responsible for long-range attractions between chains. Such interactions will govern the long-time relaxation of MR suspensions. We have synthesized monodisperse neutrally buoyant MR suspensions by density matching stabilized ferrofluid emulsion droplets with D2O. This allows us to probe the dynamics of the dipolar chains using light scattering without gravitational, interfacial, and polydispersity effects to resolve the short-wavelength dynamics of the dipolar chains. We used diffusing wave spectroscopy to measure these dynamics. The particle displacements at short times that show an independence to the field strength, but at long times exhibit a constrained, sub-diffusive motion that slows as the dipole strength is increased. The experiments are in good qualitative agreement with Brownian dynamics simulations of dipolar chains. Although there have been several important and detailed studies of the structure and interactions in MR suspensions, there has not been conclusive evidence that supports or contradicts the HT model prediction that long-range interactions exist between

Electromagnetic compatibility design and cabling system rules; Regles de conception et de cablage des systemes electroniques

Energy Technology Data Exchange (ETDEWEB)

Raimbourg, J.

2009-07-01

This report is devoted to establish EMC (Electromagnetic Compatibility) design and cabling system rules. It is intended for hardware designers in charge of designing electronic maps or integrating existing materials into a comprehensive system. It is a practical guide. The rules described in this document do not require enhanced knowledge of advanced mathematical or physical concepts. The key point is to understand phenomena with a pragmatic approach to highlight the design and protection rules. (author)

Integration of uniform design and quantum-behaved particle swarm optimization to the robust design for a railway vehicle suspension system under different wheel conicities and wheel rolling radii

Science.gov (United States)

Cheng, Yung-Chang; Lee, Cheng-Kang

2017-10-01

This paper proposes a systematic method, integrating the uniform design (UD) of experiments and quantum-behaved particle swarm optimization (QPSO), to solve the problem of a robust design for a railway vehicle suspension system. Based on the new nonlinear creep model derived from combining Hertz contact theory, Kalker's linear theory and a heuristic nonlinear creep model, the modeling and dynamic analysis of a 24 degree-of-freedom railway vehicle system were investigated. The Lyapunov indirect method was used to examine the effects of suspension parameters, wheel conicities and wheel rolling radii on critical hunting speeds. Generally, the critical hunting speeds of a vehicle system resulting from worn wheels with different wheel rolling radii are lower than those of a vehicle system having original wheels without different wheel rolling radii. Because of worn wheels, the critical hunting speed of a running railway vehicle substantially declines over the long term. For safety reasons, it is necessary to design the suspension system parameters to increase the robustness of the system and decrease the sensitive of wheel noises. By applying UD and QPSO, the nominal-the-best signal-to-noise ratio of the system was increased from -48.17 to -34.05 dB. The rate of improvement was 29.31%. This study has demonstrated that the integration of UD and QPSO can successfully reveal the optimal solution of suspension parameters for solving the robust design problem of a railway vehicle suspension system.

Analysis of vibroprotection characteristics of pneumatic relaxation seat suspension with capability of vibration energy recuperation

Directory of Open Access Journals (Sweden)

Lyashenko Mikhail

2017-01-01

Full Text Available This paper proposes mechanism and control algorithm for pneumatic relaxation system of suspension with vibration energy recuperation applied to standard vehicle operator seat (“Sibeko” company. Mathematical model of the seat pneumatic relaxation suspension with two additional air volumes was created. Pneumatic motor – recuperator activated by means of air flow from the one additional volume to another is installed in air piping between additional volumes. Computational research was made in Matlab/Simulink. Amplitude-frequency characteristics of transmission coefficient for standard and proposed suspensions were plotted for preliminary evaluation of vibration protection properties of seat suspension. Performed comparative analysis of amplitude-frequency characteristics shows that noticeable improvement of vibration protection properties of pneumatic relaxation suspension system with vibration energy recuperation in comparison with standard system both in region of resonance disturbances and in above-resonance region. Main ways for further improvement of vibration protection properties of proposed system were marked out.

Electromagnetic wave analogue of electronic diode

OpenAIRE

Shadrivov, Ilya V.; Powell, David A.; Kivshar, Yuri S.; Fedotov, Vassili A.; Zheludev, Nikolay I.

2010-01-01

An electronic diode is a nonlinear semiconductor circuit component that allows conduction of electrical current in one direction only. A component with similar functionality for electromagnetic waves, an electromagnetic isolator, is based on the Faraday effect of the polarization state rotation and is also a key component of optical and microwave systems. Here we demonstrate a chiral electromagnetic diode, which is a direct analogue of an electronic diode: its functionality is underpinned by ...

Electromagnetic radiation from beam-plasma instabilities

International Nuclear Information System (INIS)

Stenzel, R.L.; Whelan, D.A.

1982-01-01

This chapter investigates the mechanism by which unstable electrostatic waves of an electron-beam plasma system are converted into observed electromagnetic waves. Electromagnetic radiation arises from both natural beam-plasma systems (e.g., type III solar bursts and kilometric radiation), and from man-made electron beams injected from rockets and spacecraft. A pulsed magnetized discharge plasma is produced with a 1 m diam. oxide-coated cathode and the discussed experiment is performed in the quiescent afterglow. The primary beam-plasma instability involves the excitation of electrostatic plasma waves. Electromagnetic radiation from the beam-plasma system is observed with microwave antennas outside the plasma (all probes removed) or with coax-fed dipoles which can be inserted radially and axially into the plasma. The physical process of mode coupling by which electromagnetic radiation is generated in an electrostatic beam-plasma instability is identified. The results are relevant to beam injection experiments from rockets or satellites into space plasmas. The limited penetration of the beam current into the plasma due to instabilities is demonstrated

A Systems-Based Risk Assessment Framework for Intentional Electromagnetic Interference (IEMI) on Critical Infrastructures.

Science.gov (United States)

Oakes, Benjamin Donald; Mattsson, Lars-Göran; Näsman, Per; Glazunov, Andrés Alayón

2018-01-03

Modern infrastructures are becoming increasingly dependent on electronic systems, leaving them more vulnerable to electrical surges or electromagnetic interference. Electromagnetic disturbances appear in nature, e.g., lightning and solar wind; however, they may also be generated by man-made technology to maliciously damage or disturb electronic equipment. This article presents a systematic risk assessment framework for identifying possible, consequential, and plausible intentional electromagnetic interference (IEMI) attacks on an arbitrary distribution network infrastructure. In the absence of available data on IEMI occurrences, we find that a systems-based risk assessment is more useful than a probabilistic approach. We therefore modify the often applied definition of risk, i.e., a set of triplets containing scenario, probability, and consequence, to a set of quadruplets: scenario, resource requirements, plausibility, and consequence. Probability is "replaced" by resource requirements and plausibility, where the former is the minimum amount and type of equipment necessary to successfully carry out an attack scenario and the latter is a subjective assessment of the extent of the existence of attackers who possess the motivation, knowledge, and resources necessary to carry out the scenario. We apply the concept of intrusion areas and classify electromagnetic source technology according to key attributes. Worst-case scenarios are identified for different quantities of attacker resources. The most plausible and consequential of these are deemed the most important scenarios and should provide useful decision support in a countermeasures effort. Finally, an example of the proposed risk assessment framework, based on notional data, is provided on a hypothetical water distribution network. © 2017 Society for Risk Analysis.

Converting Existing Copper Wire Firing System to a Fiber Optically Controlled Firing System for Electromagnetic Pulsed Power Experiments

Science.gov (United States)

2017-12-19

Pulsed Power Experiments by Robert Borys Jr Weapons and Materials Research Directorate, ARL Colby Adams Bowhead Total Enterprise Solutions...ARL-TN-0863 ● DEC 2017 US Army Research Laboratory Converting Existing Copper Wire Firing System to a Fiber-Optically Controlled...Firing System for Electromagnetic Pulsed Power Experiments by Robert Borys Jr and Colby Adams Approved for public release

Rheological and thermal properties of suspensions of microcapsules containing phase change materials.

Science.gov (United States)

Cao, Vinh Duy; Salas-Bringas, Carlos; Schüller, Reidar Barfod; Szczotok, Anna M; Hiorth, Marianne; Carmona, Manuel; Rodriguez, Juan F; Kjøniksen, Anna-Lena

2018-01-01

The thermal and rheological properties of suspensions of microencapsulated phase change materials (MPCM) in glycerol were investigated. When the microcapsule concentration is raised, the heat storage capacity of the suspensions becomes higher and a slight decline in the thermal conductivity of the suspensions is observed. The temperature-dependent shear-thinning behaviour of the suspensions was found to be strongly affected by non-encapsulated phase change materials (PCM). Accordingly, the rheological properties of the MPCM suspensions could be described by the Cross model below the PCM melting point while a power law model best described the data above the PCM melting point. The MPCM suspensions are interesting for energy storage and heat transfer applications. However, the non-encapsulated PCM contributes to the agglomeration of the microcapsules, which can lead to higher pumping consumption and clogging of piping systems.

Microfluidic Fabrication Solutions for Tailor-Designed Fiber Suspensions

Directory of Open Access Journals (Sweden)

Helene Berthet

2016-11-01

Full Text Available Fibers are widely used in different industrial processes, for example in paper manufacturing or lost circulation problems in the oil industry. Recently, interest towards the use of fibers at the microscale has grown, driven by research in bio-medical applications or drug delivery systems. Microfluidic systems are not only directly relevant for lab-on-chip applications, but have also proven to be good model systems to tackle fundamental questions about the flow of fiber suspensions. It has therefore become necessary to provide fiber-like particles with an excellent control of their properties. We present here two complementary in situ methods to fabricate controlled micro-fibers allowing for an embedded fabrication and flow-on-a-chip platform. The first one, based on a photo-lithography principle, can be used to make isolated fibers and dilute fiber suspensions at specific locations of interest inside a microchannel. The self-assembly property of super-paramagnetic colloids is the principle of the second fabrication method, which enables the fabrication of concentrated suspensions of more flexible fibers. We propose a flow gallery with several examples of fiber flow illustrating the two methods’ capabilities and a range of recent laminar flow results.

Visualization of particle trajectories in time-varying electromagnetic fields by CAVE-type virtual reality system

International Nuclear Information System (INIS)

Ohno, Nobuaki; Ohtani, Hiroaki; Horiuchi, Ritoku; Matsuoka, Daisuke

2012-01-01

The particle kinetic effects play an important role in breaking the frozen-in condition and exciting collisionless magnetic reconnection in high temperature plasmas. Because this effect is originating from a complex thermal motion near reconnection point, it is very important to examine particle trajectories using scientific visualization technique, especially in the presence of plasma instability. We developed interactive visualization environment for the particle trajectories in time-varying electromagnetic fields in the CAVE-type virtual reality system based on VFIVE, which is interactive visualization software for the CAVE system. From the analysis of ion trajectories using the particle simulation data, it was found that time-varying electromagnetic fields around the reconnection region accelerate ions toward the downstream region. (author)

Anechoic Chamber test of the Electromagnetic Measurement System ground test unit

Science.gov (United States)

Stevenson, L. E.; Scott, L. D.; Oakes, E. T.

1987-04-01

The Electromagnetic Measurement System (EMMS) will acquire data on electromagnetic (EM) environments at key weapon locations on various aircraft certified for nuclear weapons. The high-frequency ground unit of the EMMS consists of an instrumented B61 bomb case that will measure (with current probes) the localized current density resulting from an applied EM field. For this portion of the EMMS, the first system test was performed in the Anechoic Chamber Facility at Sandia National Laboratories, Albuquerque, New Mexico. The EMMS pod was subjected to EM radiation at microwave frequencies of 1, 3, and 10 GHz. At each frequency, the EMMS pod was rotated at many positions relative to the microwave source so that the individual current probes were exposed to a direct line-of-sight illumination. The variations between the measured and calculated electric fields for the current probes with direct illumination by the EM source are within a few db. The results obtained from the anechoic test were better than expected and verify that the high frequency ground portion of the EMMS will accurately measure the EM environments for which it was designed.

Roll and pitch independently tuned interconnected suspension: modelling and dynamic analysis

Science.gov (United States)

Xu, Guangzhong; Zhang, Nong; Roser, Holger M.

2015-12-01

In this paper, a roll and pitch independently tuned hydraulically interconnected passive suspension is presented. Due to decoupling of vibration modes and the improved lateral and longitudinal stability, the stiffness of individual suspension spring can be reduced for improving ride comfort and road grip. A generalised 14 degree-of-freedom nonlinear vehicle model with anti-roll bars is established to investigate the vehicle ride and handling dynamic responses. The nonlinear fluidic model of the hydraulically interconnected suspension is developed and integrated with the full vehicle model to investigate the anti-roll and anti-pitch characteristics. Time domain analysis of the vehicle model with the proposed suspension is conducted under different road excitations and steering/braking manoeuvres. The dynamic responses are compared with conventional suspensions to demonstrate the potential of enhanced ride and handling performance. The results illustrate the model-decoupling property of the hydraulically interconnected system. The anti-roll and anti-pitch performance could be tuned independently by the interconnected systems. With the improved anti-roll and anti-pitch characteristics, the bounce stiffness and ride damping can be optimised for better ride comfort and tyre grip.

Gauge theory of weak, electromagnetic and dual electromagnetic interactions

International Nuclear Information System (INIS)

Soln, J.

1980-01-01

An SU 2 x U 1 algebra, in addition to the ordinary electric charge, also establishes the existence of the dual electric charge. This is taken as an indication of the existence of dual electromagnetic interactions in nature. Here, the unification of weak, electromagnetic and dual electromagnetic interactions is performed. The Yang-Mills-type group which contains the electromagnetic, dual electromagnetic and weak currents is SUsub(L,2) x U 1 x U' 1 . The masses of vector mesons are generated through the Higgs-Kibble mechanism. A simple consistency requirement suggests that dual electromagnetism and ordinary electromagnetism have the same strengths, leading the theory to a rather good agreement with experiments. (author)

A simple route to prepare stable hydroxyapatite nanoparticles suspension

International Nuclear Information System (INIS)

Han Yingchao; Wang Xinyu; Li Shipu

2009-01-01

A simple ultrasound assisted precipitation method with addition of glycosaminoglycans (GAGs) is proposed to prepare stable hydroxyapatite (HAP) nanoparticles suspension from the mixture of Ca(H 2 PO 4 ) 2 solution and Ca(OH) 2 solution. The product was characterized by XRD, FT-IR, TEM, HRTEM and particle size, and zeta potential analyzer. TEM observation shows that the suspension is composed of 10-20 nm x 20-50 nm short rod-like and 10-30 nm similar spherical HAP nanoparticles. The number-averaged particle size of stable suspension is about 30 nm between 11.6 and 110.5 nm and the zeta potential is -60.9 mV. The increase of stability of HAP nanoparticles suspension mainly depends on the electrostatic effect and steric effect of GAGs. The HAP nanoparticles can be easily transported into the cancer cells and exhibit good potential as gene or drug carrier system.

Characteristics of electromagnetic forces of a single winding EDS MAGLEV system

Energy Technology Data Exchange (ETDEWEB)

Hong, Soon Heum [Korea High Speed Rail Construction Authority (Korea, Republic of); Cha, Guee Soo [Seoul National University (Korea, Republic of); Hahn, Song Yop [Soonchunhyang University (Korea, Republic of)

1995-07-01

This paper describes the characteristics of electromagnetic forces of Combined superconducting maglev system. Generation of the levitation, the propulsion and the guidance force by a single coil is proved by the phasor analysis. It is also shown that double-layered configuration has better characteristics in efficiency, pulsation of the forces and drag ration than single-layered configuration. (author). 3 refs., 7 figs., 1 tab.

Controllable damping of high-Q violin modes in fused silica suspension fibers

Energy Technology Data Exchange (ETDEWEB)

Dmitriev, A V; Mescheriakov, S D; Mitrofanov, V P [Faculty of Physics, Moscow State University, Moscow 119991 (Russian Federation); Tokmakov, K V, E-mail: dmitriev@hbar.phys.msu.r, E-mail: mitr@hbar.phys.msu.r [Present address: Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

2010-01-21

Fused silica fiber suspension of the test masses will be used in the interferometric gravitational wave detectors of the next generation. This allows a significant reduction of losses in the suspension and thermal noise associated with the suspension. Unfortunately, unwanted violin modes may be accidentally excited in the suspension fibers. The Q-factor of the violin modes also exceeds 10{sup 8}. They have a ring-down time that is too long and may complicate the stable control of the interferometer. Results of the investigation of a violin mode active damping system are described. An original sensor and actuator were especially developed to realize the effective coupling of a thin, optically transparent, non-conducting fused silica fiber with an electric circuit. The damping system allowed the changing of the violin mode's damping rate over a wide range.

Controllable damping of high-Q violin modes in fused silica suspension fibers

International Nuclear Information System (INIS)

Dmitriev, A V; Mescheriakov, S D; Mitrofanov, V P; Tokmakov, K V

2010-01-01

Fused silica fiber suspension of the test masses will be used in the interferometric gravitational wave detectors of the next generation. This allows a significant reduction of losses in the suspension and thermal noise associated with the suspension. Unfortunately, unwanted violin modes may be accidentally excited in the suspension fibers. The Q-factor of the violin modes also exceeds 10 8 . They have a ring-down time that is too long and may complicate the stable control of the interferometer. Results of the investigation of a violin mode active damping system are described. An original sensor and actuator were especially developed to realize the effective coupling of a thin, optically transparent, non-conducting fused silica fiber with an electric circuit. The damping system allowed the changing of the violin mode's damping rate over a wide range.

A monitor for the laboratory evaluation of control integrity in digital control systems operating in harsh electromagnetic environments

Science.gov (United States)

Belcastro, Celeste M.; Fischl, Robert; Kam, Moshe

1992-01-01

This paper presents a strategy for dynamically monitoring digital controllers in the laboratory for susceptibility to electromagnetic disturbances that compromise control integrity. The integrity of digital control systems operating in harsh electromagnetic environments can be compromised by upsets caused by induced transient electrical signals. Digital system upset is a functional error mode that involves no component damage, can occur simultaneously in all channels of a redundant control computer, and is software dependent. The motivation for this work is the need to develop tools and techniques that can be used in the laboratory to validate and/or certify critical aircraft controllers operating in electromagnetically adverse environments that result from lightning, high-intensity radiated fields (HIRF), and nuclear electromagnetic pulses (NEMP). The detection strategy presented in this paper provides dynamic monitoring of a given control computer for degraded functional integrity resulting from redundancy management errors, control calculation errors, and control correctness/effectiveness errors. In particular, this paper discusses the use of Kalman filtering, data fusion, and statistical decision theory in monitoring a given digital controller for control calculation errors.

One-Quarter-Car Active SuspensionModel Verification

Directory of Open Access Journals (Sweden)

Hyniova Katerina

2017-01-01

Full Text Available Suspension system influences both the comfort and safety of the passengers. In the paper, energy recuperation and management in automotive suspension systems with linear electric motors that are controlled by a designed H∞ controller to generate a variable mechanical force for a car damper is presented. Vehicle shock absorbers in which forces are generated in response to feedback signals by active elements obviously offer increased design flexibility compared to the conventional suspensions with passive elements (springs and dampers. The main advantage of the proposed solution that uses a linear AC motor is the possibility to generate desired forces acting between the unsprung (wheel and sprung (one-quarter of the car body mass masses of the car, providing good insulation of the car sprung mass from the road surface roughness and load disturbances. As shown in the paper, under certain circumstances linear motors as actuators enable to transform mechanical energy of the vertical car vibrations to electrical energy, accumulate it, and use it when needed. Energy flow control enables to reduce or even eliminate the demands on the external power source. In particular, the paper is focused on experiments with active shock absorber that has been taken on the designed test bed and the way we developed an appropriate input signal for the test bed that as real road disturbance acts upon the vibration absorber and the obtained results are evaluated at the end. Another important point the active suspension design should satisfy is energy supply control that is made via standard controller modification, and which allows changing amount of energy required by the system. Functionality of the designed controller modification was verified taking various experiments on the experiment stand as mentioned in the paper.

Low-frequency electromagnetic radiation field interaction with cerebral nervous MT

International Nuclear Information System (INIS)

Gao Feng; Zhou Yi; Xiao Detao; Zhang Dengyu

2009-01-01

We investigate the interaction characteristics and mechanism of electromagnetic radiation field and cerebral nervous system. When the electromagnetic radiation is non-ionization low-frequency electromagnetic field, the two-state physical system in the cytoskeletal microtubule (MT) can be quantized. The state of information bits in cerebral neurons system is described by density matrix, and the system dynamics equation is established and solved. It indicates that when the brain is exposed to non-ionization low-frequency electromagnetic field, the density matrix non-opposite angle element of cerebral nervous qubit will never be zero, its quantum coherence characteristic can keep well, and the brain function will also be not damaged. (authors)

Study on Electromagnetic Interference of high-speed railway EMU

OpenAIRE

CHENG Qiang; LIU Jin-jiang; CHENG Ning

2013-01-01

Electromagnetic radiation generated by pantograph-catenaries detachment is one of the inevitable problems with the development of high-speed railway this paper is focusing on the generating mechanism and characteristics of electromagnetic noise caused by pantograph-catenaries system. Based on previous research, we build an integrated model of catenaries and locomotive system, and study the electromagnetic disturbance characteristics using software FEKO． The simulation experiment results in th...

Asystole following Reintubation during Suspension Laryngoscopy

Directory of Open Access Journals (Sweden)

Sheryl H. Glassman

2012-01-01

Full Text Available Transient increase in heart rate and mean arterial pressure commonly occur during manipulation of the airway via direct laryngoscopy. This phenomenon is understood to be due to a sympathetic nervous system reflex causing an increase in plasma catecholamines. Rarely, severe bradycardia and possible asystole can occur following laryngoscopy. One previous report described asystole during suspension laryngoscopy after uneventful direct laryngoscopy. Here we report a case of asystole occurring at the time of reinsertion and cuff inflation of an endotracheal tube in a patient who had been hemodynamically stable during initial direct laryngoscopy and the ensuing suspension laryngoscopy. The asystole was immediately recognized and successful cardiopulmonary resuscitation was performed with the patient returning to baseline sinus rhythm. Cardiac arrest following laryngoscopy is rare. This case highlights the importance of continued vigilance even after the initial manipulations of the airway by both direct laryngoscopy and suspension laryngoscopy are to be performed. Identifying patients who may benefit from premedication with a vagolytic drug may prevent adversity. Preoperative heart rate analysis can identify patients with strong vagal tone.

Tribology of swollen starch granule suspensions from maize and potato.

Science.gov (United States)

Zhang, Bin; Selway, Nichola; Shelat, Kinnari J; Dhital, Sushil; Stokes, Jason R; Gidley, Michael J

2017-01-02

The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Mathematical models for suspension bridges nonlinear structural instability

CERN Document Server

Gazzola, Filippo

2015-01-01

This work provides a detailed and up-to-the-minute survey of the various stability problems that can affect suspension bridges. In order to deduce some experimental data and rules on the behavior of suspension bridges, a number of historical events are first described, in the course of which several questions concerning their stability naturally arise. The book then surveys conventional mathematical models for suspension bridges and suggests new nonlinear alternatives, which can potentially supply answers to some stability questions. New explanations are also provided, based on the nonlinear structural behavior of bridges. All the models and responses presented in the book employ the theory of differential equations and dynamical systems in the broader sense, demonstrating that methods from nonlinear analysis can allow us to determine the thresholds of instability.

Electromagnetic Coupling Between High Intensity LHC Beams and the Synchrotron Radiation Monitor Light Extraction System

CERN Document Server

Andreazza, W; Bravin, E; Caspers, F; Garlasch`e, M; Gras, J; Goldblatt, A; Lefevre, T; Jones, R; Metral, E; Nosych, A; Roncarolo_, F; Salvant, B; Trad, G; Veness, R; Vollinger, C; Wendt, M

2013-01-01

The CERN LHC is equipped with two Synchrotron Radiation Monitor (BSRT) systems used to characterise transverse and longitudinal beam distributions. Since the end of the 2011 LHC run the light extraction system, based on a retractable mirror, has suffered deformation and mechanical failure that is correlated to the increase in beam intensity. Temperature probes have associated these observations to a strong heating of the mirror support with a dependence on the longitudinal bunch length and shape, indicating the origin as electromagnetic coupling between the beam and the structure. This paper combines all this information with the aim of characterising and improving the system in view of its upgrade during the current LHC shutdown. Beam-based observations are presented along with electromagnetic and thermomechanical simulations and complemented by laboratory measurements, including the study of the RF properties of different mirror bulk and coating materials.

Electromagnetic Waves

DEFF Research Database (Denmark)

This book is dedicated to various aspects of electromagnetic wave theory and its applications in science and technology. The covered topics include the fundamental physics of electromagnetic waves, theory of electromagnetic wave propagation and scattering, methods of computational analysis......, material characterization, electromagnetic properties of plasma, analysis and applications of periodic structures and waveguide components, etc....

Evaluating Suspension Formulations of Theophylline Cocrystals With Artificial Sweeteners.

Science.gov (United States)

Aitipamula, Srinivasulu; Wong, Annie B H; Kanaujia, Parijat

2018-02-01

Pharmaceutical cocrystals have garnered significant interest as potential solids to address issues associated with formulation development of drug substances. However, studies concerning the understanding of formulation behavior of cocrystals are still at the nascent stage. We present results of our attempts to evaluate suspension formulations of cocrystals of an antiasthmatic drug, theophylline, with 2 artificial sweeteners. Stability, solubility, drug release, and taste of the suspension formulations were evaluated. Suspension that contained cocrystal with acesulfame showed higher drug release rate, while a cocrystal with saccharin showed a significant reduction in drug release rate. The cocrystal with saccharin was found stable in suspension for over 9 weeks at accelerated test condition; in contrast, the cocrystal with acesulfame was found unstable. Taste analysis using an electronic taste-sensing system revealed improved sweetness of the suspension formulations with cocrystals. Theophylline has a narrow therapeutic index with a short half-life which necessitates frequent dosing. This adversely impacts patient compliance and enhances risk of gastrointestinal and cardiovascular adverse effects. The greater thermodynamic stability, sweetness, and sustained drug release of the suspension formulation of theophylline-saccharin could offer an alternative solution to the short half-life of theophylline and make it a promising formulation for treating asthmatic pediatric and geriatric patients. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Compressed Air Production Using Vehicle Suspension

Directory of Open Access Journals (Sweden)

Ninad Arun Malpure

2015-08-01

Full Text Available Abstract Generally compressed air is produced using different types of air compressors which consumes lot of electric energy and is noisy. In this paper an innovative idea is put forth for production of compressed air using movement of vehicle suspension which normal is wasted. The conversion of the force energy into the compressed air is carried out by the mechanism which consists of the vehicle suspension system hydraulic cylinder Non-return valve air compressor and air receiver. We are collecting air in the cylinder and store this energy into the tank by simply driving the vehicle. This method is non-conventional as no fuel input is required and is least polluting.

Ultra-Wideband, Short Pulse Electromagnetics 9

CERN Document Server

Rachidi, Farhad; Kaelin, Armin; Sabath, Frank; UWB SP 9

2010-01-01

Ultra-wideband (UWB), short-pulse (SP) electromagnetics are now being used for an increasingly wide variety of applications, including collision avoidance radar, concealed object detection, and communications. Notable progress in UWB and SP technologies has been achieved by investigations of their theoretical bases and improvements in solid-state manufacturing, computers, and digitizers. UWB radar systems are also being used for mine clearing, oil pipeline inspections, archeology, geology, and electronic effects testing. Ultra-wideband Short-Pulse Electromagnetics 9 presents selected papers of deep technical content and high scientific quality from the UWB-SP9 Conference, which was held from July 21-25, 2008, in Lausanne, Switzerland. The wide-ranging coverage includes contributions on electromagnetic theory, time-domain computational techniques, modeling, antennas, pulsed-power, UWB interactions, radar systems, UWB communications, and broadband systems and components. This book serves as a state-of-the-art r...

Stability of an extemporaneously compounded minoxidil oral suspension.