Recommended Practices for the Safe Design and Operation of Flywheels

Energy Technology Data Exchange (ETDEWEB)

Bender, Donald Arthur [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-12-01

Flywheel energy storage systems are in use globally in increasing numbers . No codes pertaining specifically to flywheel energy storage exist. A number of industrial incidents have occurred. This protocol recommends a technical basis for safe flywheel de sign and operation for consideration by flywheel developers, users of flywheel systems and standards setting organizations.

The New Structure Design and Analysis of Energy Storage of Flywheel of Split Rotor

Directory of Open Access Journals (Sweden)

Peng Xu

2015-02-01

Full Text Available The braking of the rail transit train consumes a great quantity of energy, and the thermal energy produced in the process of braking can affect the normal operation of the transit train. Thus recycling the braking energy becomes a research hotspot of urban rail train. This paper made an overall analysis of regenerative braking process, the rationale, and the main features and then put forward the optimizing the structure of the composite flywheel concept and design calculation method. This paper also designs a new flywheel structure which can be applied on urban rail operating system. The new flywheel structure should be checked by finite element method and the radius of the rotor should be defined under the condition of meeting the requirements of carbon fiber material strength. Meanwhile, compared with the solid flywheel under the same condition, analysis shows that the maximum rotary inertia of the new flywheel and the quality energy density increased, and the discharge depth also perks up.

Operating characteristics of a 0.87 kW-hr flywheel energy storage module

Science.gov (United States)

Loewenthal, S. H.; Scibbe, H. W.; Parker, R. D.; Zaretsky, E. V.

1985-01-01

Discussion is given of the design and loss characteristics of 0.87 kW-hr (peak) flywheel energy storage module suitable for aerospace and automotive applications. The maraging steel flywheel rotor, a 46-cm- (18-in-) diameter, 58-kg (128-lb) tapered disk, delivers 0.65 kW-hr of usable energy between operating speeds of 10,000 and 20,000 rpm. The rotor is supported by 20- and 25-mm bore diameter, deep-groove ball bearings, lubricated by a self-replenishing wick type lubrication system. To reduce aerodynamic losses, the rotor housing was evacuated to vacuum levels from 40 to 200 millitorr. Dynamic rotor instabilities uncovered during testing necessitated the use of an elastometric-bearing damper to limit shaft excursions. Spindown losses from bearing, seal, and aerodynamic drag at 50 millitorr typically ranged from 64 to 193 W at 10,000 and 20,000 rpm, respectively. Discharge efficiency of the flywheel system exceeded 96 percent at torque levels greater than 21 percent of rated torque.

Tilted-ring modelling of disk galaxies : Anomalous gas

NARCIS (Netherlands)

Jozsa, G. I. G.; Niemczyk, C.; Klein, U.; Oosterloo, T. A.

We report our ongoing work on kinematical modelling of HI in disk galaxies. We employ our new software TiRiFiC (Tilted-Ring-Fitting-Code) in order to derive tilted-ring models by fitting artificial HI data cubes to observed ones in an automated process. With this technique we derive very reliable

High speed superconducting flywheel system for energy storage

Science.gov (United States)

Bornemann, H. J.; Urban, C.; Boegler, P.; Ritter, T.; Zaitsev, O.; Weber, K.; Rietschel, H.

1994-12-01

A prototype of a flywheel system with auto stable high temperature superconducting bearings was built and tested. The bearings offered good vertical and lateral stability. A metallic flywheel disk, ø 190 mm x 30 mm, was safely rotated at speeds up to 15000 rpm. The disk was driven by a 3 phase synchronous homopolar motor/generator. Maximum energy capacity was 3.8 Wh, maximum power was 1.5 KW. The dynamic behavior of the prototype was tested, characterized and evaluated with respect to axial and lateral stiffness, decay torques (bearing drag), vibrational modes and critical speeds. The bearings supports a maximum weight of 65 N at zero gap, axial and lateral stiffness at 1 mm gap were 440 N/cm and 130 N/cm, respectively. Spin down experiments were performed to investigate the energy efficiency of the system. The decay rate was found to depend upon background pressure in the vacuum chamber and upon the gap width in the bearing. At a background pressure of 5x10 -4 Torr, the coefficient of friction (drag-to-lift ratio) was measured to be 0.000009 at low speeds for 6 mm gap width in the bearing. Our results indicate that further refinement of this technology will allow operation of higly efficient superconducting flywheels in the kWh range.

A Multi-ringed, Modestly Inclined Protoplanetary Disk around AA Tau

Energy Technology Data Exchange (ETDEWEB)

Loomis, Ryan A.; Öberg, Karin I.; Andrews, Sean M.; MacGregor, Meredith A., E-mail: rloomis@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

2017-05-01

AA Tau is the archetype for a class of stars with a peculiar periodic photometric variability thought to be related to a warped inner disk structure with a nearly edge-on viewing geometry. We present high resolution (∼0.″2) ALMA observations of the 0.87 and 1.3 mm dust continuum emission from the disk around AA Tau. These data reveal an evenly spaced three-ringed emission structure, with distinct peaks at 0.″34, 0.″66, and 0.″99, all viewed at a modest inclination of 59.°1 ± 0.°3 (decidedly not edge-on). In addition to this ringed substructure, we find non-axisymmetric features, including a “bridge” of emission that connects opposite sides of the innermost ring. We speculate on the nature of this “bridge” in light of accompanying observations of HCO{sup +} and {sup 13}CO ( J = 3–2) line emission. The HCO{sup +} emission is bright interior to the innermost dust ring, with a projected velocity field that appears rotated with respect to the resolved disk geometry, indicating the presence of a warp or inward radial flow. We suggest that the continuum bridge and HCO{sup +} line kinematics could originate from gap-crossing accretion streams, which may be responsible for the long-duration dimming of optical light from AA Tau.

A Multi-ringed, Modestly Inclined Protoplanetary Disk around AA Tau

International Nuclear Information System (INIS)

Loomis, Ryan A.; Öberg, Karin I.; Andrews, Sean M.; MacGregor, Meredith A.

2017-01-01

AA Tau is the archetype for a class of stars with a peculiar periodic photometric variability thought to be related to a warped inner disk structure with a nearly edge-on viewing geometry. We present high resolution (∼0.″2) ALMA observations of the 0.87 and 1.3 mm dust continuum emission from the disk around AA Tau. These data reveal an evenly spaced three-ringed emission structure, with distinct peaks at 0.″34, 0.″66, and 0.″99, all viewed at a modest inclination of 59.°1 ± 0.°3 (decidedly not edge-on). In addition to this ringed substructure, we find non-axisymmetric features, including a “bridge” of emission that connects opposite sides of the innermost ring. We speculate on the nature of this “bridge” in light of accompanying observations of HCO + and 13 CO ( J = 3–2) line emission. The HCO + emission is bright interior to the innermost dust ring, with a projected velocity field that appears rotated with respect to the resolved disk geometry, indicating the presence of a warp or inward radial flow. We suggest that the continuum bridge and HCO + line kinematics could originate from gap-crossing accretion streams, which may be responsible for the long-duration dimming of optical light from AA Tau.

Superconducting bearings in flywheels

Energy Technology Data Exchange (ETDEWEB)

Coombs, T.A.; Campbell, A.M.; Ganney, I.; Lo, W. [Cambridge Univ. (United Kingdom). Interdisciplinary Research Centre in Superconductivity (IRC); Twardowski, T. [International Energy Systems, Chester High Road, Neston, South Wirral (United Kingdom); Dawson, B. [British Nuclear Fuels, Capenhurst, South Wirral (United Kingdom)

1998-05-01

Investigations are being carried out into the use of superconducting magnetic bearings to levitate energy storage flywheels. In a planned program of work, Cambridge University are aiming to produce a practical bearing system for Pirouette(TM). The Pirouette(TM) system is designed to provide 5 kWh of recoverable energy which is currently recoverable at a rate of 5 kW (future revisions will provide up to 50 kW). IES (a British Nuclear Fuels subsidiary) the owners of the Pirouette(TM) machine have supplied Cambridge with a flywheel. This flywheel weighs >40 kg and is being levitated using an Evershed-type arrangement in which the superconductor is being used to stabilize the interaction between two magnets. To date we have demonstrated stable levitation in static and low speed tests in a rig designed for low speeds of rotation in air. A second rig which is currently under construction at BNFL will run in vacuum at speeds of up to 50 (orig.) 5 refs.

RESOLVED CO GAS INTERIOR TO THE DUST RINGS OF THE HD 141569 DISK

Energy Technology Data Exchange (ETDEWEB)

Flaherty, Kevin M.; Hughes, A. Meredith; Zachary, Julia [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); Andrews, Sean M.; Qi, Chunhua; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Boley, Aaron C.; White, Jacob A. [Department of Physics and Astronomy, University of British Columbia, Vancouver BC (Canada); Harney, Will [Department of Physics and Astronomy, Union College, Schenectady, NY (United States)

2016-02-10

The disk around HD 141569 is one of a handful of systems whose weak infrared emission is consistent with a debris disk, but still has a significant reservoir of gas. Here we report spatially resolved millimeter observations of the CO(3-2) and CO(1-0) emission as seen with the Submillimeter Array and CARMA. We find that the excitation temperature for CO is lower than expected from cospatial blackbody grains, similar to previous observations of analogous systems, and derive a gas mass that lies between that of gas-rich primordial disks and gas-poor debris disks. The data also indicate a large inner hole in the CO gas distribution and an outer radius that lies interior to the outer scattered light rings. This spatial distribution, with the dust rings just outside the gaseous disk, is consistent with the expected interactions between gas and dust in an optically thin disk. This indicates that gas can have a significant effect on the location of the dust within debris disks.

Composite flywheel development completion report, May 1--September 30, 1976

Energy Technology Data Exchange (ETDEWEB)

Huddleston, R. L.; Kelly, J. J.; Knight, C. E.

1977-05-01

The program to design, fabricate, and performance test a prototype, vehicular-sized, composite flywheel is described. The overall program scope encompasses development of both the flywheel and its containment; however, the FY 1976-1976T objective was directed toward development of the flywheel and testing it in existing facilities. The development effort was successful, leading to successful testing of a flywheel design which demonstrated an energy density performance of 10.1 Wh/lb during spin testing. The initial application selected for development of the composite flywheel was the heat engine/flywheel hybrid propulsion system for a vehicle. This application was selected by the ERDA Advanced Physical Methods Branch staff because of its high potential for conservation of petroleum fuel in both the near and far-term time frames. Other applications, such as utility load leveling, represent potential areas for significant energy savings but require more extensive development programs and funding resources. Successful development of a high-performance, composite, vehicular flywheel represents one step along the development path leading toward larger, higher-energy storage flywheel applications.

Flywheels: Mobile applications

Science.gov (United States)

Rabenhorst, D. W.

1981-06-01

The characteristics of modern flywheel energy storage systems uniquely qualify the flywheel for use in a variety of road vehicles, off road vehicles and rail vehicles. About sixty studies and vehicle demonstration programs in a dozen countries indicate that future such flywheel powered vehicles will have improved performance, reduced energy and fuel consumption and reduced life cycle cost. Flywheel capabilities and mobile applications were reviewed.

Power system for tokamak fusion experiments. Motor generator with flywheel effect

International Nuclear Information System (INIS)

Miyachi, Kengo

1997-01-01

JT-60 requires an enormous electric power pulse about 1,300 MVA periodically for its plasma initiation, containment and heating. JT-60 could not receive all electric power from a commercial line for plasma experiment except about 160 MVA because the 275 kV commercial line has some limitations. Therefore JT-60 needs huge electric power sources. The power supply system of JT-60 has 3 motor generators (MG). The total capacity of MG is 1,115 MVA that consists of a toroidal MG (TMG), poloidal MG (PMG) and Heating power supply MG (HMG), and each MG has a huge flywheel effect. For example, TMG has a 4.02 GJ energy yield that consists of 6 disk flywheel. The total weight of flywheel of TMG is 650 ton. This report describes the structure, operating system, and maintenance history of 3 types of MG. (author)

Analysis of the energy capacity of rim-spoke composite flywheels

International Nuclear Information System (INIS)

Moorlat, P.A.; Portnov, G.G.

1986-01-01

The rim-spoke flywheel consisting of a rim, connected to the hub by spokes encompassing the rim periphery, is one of the most promising types of energy accumulators. For the rational design of rim-spoke flywheels, the authors investigate the dependence of their mass energy capacity and their volume energy capacity; the limit speed on the geometric parameters of the flywheel and the properties of the composites used in making the rim and the spokes are also examined. It is shown through various programs, worked out for analyzing the energy capacity of rim-spoke flywheels, that they can substantially facilitate the designing of such flywheels according to specified requirements that their operational characteristics have to meet

Optimum design of flywheel energy storage system using superconducting magnetic bearings

Energy Technology Data Exchange (ETDEWEB)

Lee, Soo Hun; Lee, Jeung Gun; Kim, Jong Soo [Ajou University, Suwon (Korea, Republic of)

1997-07-01

Electricity demands changes by as much as 30% over a 12-hour period and results in significant costs for utilities as power output get adjusted to meet these changes. The purpose of High-Temperature Superconducting Flywheel Energy Storage System (HTS FES) is to store unused nighttime electricity until it is needed during the daytime. The HTS FES is designed by using flywheel shape function with uniform stress. Natural frequencies and natural modes are estimated by using Finite Element Analysis and correlated with the experimental results. By performing a vibration test, the stiffness and the damping ratio of the flux line, the flux pinning phenomenon are measured Using the modal parameters of each component and the measured stiffness, damping coefficient, the IDEAS System Dynamics Analysis is performed and frequency response function(FRF) of the joined system is obtained. The effect of tangential torque on flywheel has been studied using cantilever shaft with rotor at free end. To obtain the equation of motion, the Lagrange`s equation and the assumed-mode method are used. As a admissible function, a free vibration mode of clamped-free beam is used. The eigenvalues are computed and the stability boundaries are obtained. 19 refs., 33 figs. (author)

Lightweight flywheel containment

Science.gov (United States)

Smith, James R.

2004-06-29

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

JET flywheel generators

International Nuclear Information System (INIS)

Huart, M.; Sonnerup, L.

1986-01-01

Two large vertical shaft flywheel generators each provides the JET device with peak power up to 400 MW and energy up to 2600 MJ per pulse to induce and confine the multi-mega-ampere plasma current. The integrated rotor flywheel consists of a 650 tonne/10 m diameter rim carrying the poles of the machine. The energy is stored kinetically during a 9 min interval of acceleration from half-speed to full-speed and then released during a 20 s long deceleration. A design life of 100 000 cycles at full energy rating was specified. The mechanical design and construction of the generators is reviewed. Particular attention is paid to the assessment of the stresses and fatigue life of the rotor system, its dynamic behaviour (rim movement, critical speed and balancing) and on the performance in operation of the large thrust bearing. (author)

Safety in unlimited power supply. Method and means of parallel operation of flywheel aggregates. [parallel operation of flywheel machines

Energy Technology Data Exchange (ETDEWEB)

Krause, E [Struever (A.) K.G., Hamburg (Germany, F.R.)

1975-11-01

A special type of Diesel emergency generator sets, i.e., with flywheel machines is described. Construction and operation of a flywheel machine are described and reasons are given for a possible or necessary parallel operation. The basic requirements for parallel operation are explained and the intrinsic operation is described. Special designs are also presented.

DISCOVERY OF AN EDGE-ON DEBRIS DISK WITH A DUST RING AND AN OUTER DISK WING-TILT ASYMMETRY

International Nuclear Information System (INIS)

Kasper, Markus; Apai, Dániel; Wagner, Kevin; Robberto, Massimo

2015-01-01

Using Very Large Telescope/SPHERE near-infrared dual-band imaging and integral field spectroscopy, we discovered an edge-on debris disk around the 17 Myr old A-type member of the Scorpius–Centaurus OB association HD 110058. The edge-on disk can be traced to about 0.″6 or 65 AU projected separation. In its northern and southern wings, the disk shows at all wavelengths two prominent, bright, and symmetrically placed knots at 0.″3 or 32 AU from the star. We interpret these knots as a ring of planetesimals whose collisions may produce most of the dust observed in the disk. We find no evidence for a bow in the disk, but we identify a pair of symmetric, hooklike features in both wings. Based on similar features in the Beta Pictoris disk, we propose that this wing-tilt asymmetry traces either an outer planetesimal belt that is inclined with respect to the disk midplane or radiation-pressure-driven dust blown out from a yet unseen inner belt that is inclined with respect to the disk midplane. The misaligned inner or outer disk may be a result of interaction with a yet unseen planet. Overall, the disk geometry resembles the nearby disk around Beta Pictoris, albeit seen at smaller radial scales

Development of superconductor application technology - Flywheel energy storage system using superconducting magnetic bearing

Energy Technology Data Exchange (ETDEWEB)

Lee, Soo Hun; Oh, Hueng Kuk; Yun, Keyng Reyl; Lee, Jeung Kun [Ahju University, Suwon (Korea, Republic of)

1996-06-01

Electricity must be used simultaneously with its generation. Existing storage methods either are dependent on special geography, are too expensive,= or are too inefficient. Electricity demand changes by as much as 30% over a 12-hour period and result in significant costs for utilities as power output get adjusted to meet these changes. The purpose of HTS FES is to store unused nighttime electricity until it is needed during the daytime. If every element of a rotating flywheel is stressed to a prescribed allowable value, the flywheel material will clearly be used in most efficient manner. The uniformlt stressed flywheel is about 25% stronger than a flat disk. The gap between superconductor and permanent magnet was 1.85 mm, and using bearing connector with the values, joining superconductor to permanent magnet Using bolt connector, joining permanent magnet to flywheel. Joined system is excited by exciting function that magnitude is 1, range is 0 up to 4000 HZ. 3 rd and 4 th natural frequency, 1857 HZ and 2340 HZ, in X direction and 2 nd natural frequency, 28.57 HZ, are avoided to prevent resonance. 15 refs., 11 tabs., 53 figs. (author)

Flywheels for Low-Speed Kinetic Energy Storage Systems

Energy Technology Data Exchange (ETDEWEB)

Portnov, G.; Cruz, I.; Arias, F.; Fiffe, R. P.

2003-07-01

A brief overview of different steel disc-type flywheels is presented. It contents the analysis of relationship between stress-state and kinetic energy of rotating body, comparison of the main characteristics of flywheels and description of their optimization procedures. It is shown that profiles of the discs calculated on a basis of plane stress-state assumption may be considered only as a starting point for its further improvement using 3-D approach. The aim of the review is to provide a designer for a insight into problem of shaping of steel flywheels. (Author) 19 refs.

AN ASSESSMENT OF FLYWHEEL HIGH POWER ENERGY STORAGE TECHNOLOGY FOR HYBRID VEHICLES

Energy Technology Data Exchange (ETDEWEB)

Hansen, James Gerald [ORNL

2012-02-01

An assessment has been conducted for the DOE Vehicle Technologies Program to determine the state of the art of advanced flywheel high power energy storage systems to meet hybrid vehicle needs for high power energy storage and energy/power management. Flywheel systems can be implemented with either an electrical or a mechanical powertrain. The assessment elaborates upon flywheel rotor design issues of stress, materials and aspect ratio. Twelve organizations that produce flywheel systems submitted specifications for flywheel energy storage systems to meet minimum energy and power requirements for both light-duty and heavy-duty hybrid applications of interest to DOE. The most extensive experience operating flywheel high power energy storage systems in heavy-duty and light-duty hybrid vehicles is in Europe. Recent advances in Europe in a number of vehicle racing venues and also in road car advanced evaluations are discussed. As a frame of reference, nominal weight and specific power for non-energy storage components of Toyota hybrid electric vehicles are summarized. The most effective utilization of flywheels is in providing high power while providing just enough energy storage to accomplish the power assist mission effectively. Flywheels are shown to meet or exceed the USABC power related goals (discharge power, regenerative power, specific power, power density, weight and volume) for HEV and EV batteries and ultracapacitors. The greatest technical challenge facing the developer of vehicular flywheel systems remains the issue of safety and containment. Flywheel safety issues must be addressed during the design and testing phases to ensure that production flywheel systems can be operated with adequately low risk.

Design of magnetic flywheel control for performance improvement of fuel cells used in vehicles

International Nuclear Information System (INIS)

Huang, Chung-Neng; Chen, Yui-Sung

2017-01-01

Because hydrogen can be extracted naturally and stored for a long time, different types of fuel cells have been developed to generate clean power, particularly for use in vehicles. However, the power demand of a running vehicle leads to unstable and irregular loading of fuel cells. This not only reduces fuel cell lifespan and efficiency but also affects driving safety when the slow output response cannot satisfy an abrupt increase in power demand. Magnetic flywheels with characteristics such as high energy density, high-speed charging ability, and low loss have been extensively used in Formula One cars. This study developed a hybrid powertrain in which a magnetic flywheel system (MFS) is integrated with the fuel cells to solve the aforementioned problems. Moreover, an auto-tuning proportional–integral–derivative (PID) controller based on the controls of a multiple adaptive neuro-fuzzy interference system and particle swarm optimization was designed for MFS control. Furthermore, MATLAB/Simulink simulations considering an FTP-75 urban driving cycle were conducted, and a variability improvement of approximately 27.3% in fuel cell output was achieved. - Highlights: • A hybrid powertrain integrating the magnetic flywheel and fuel cells is proposed. • An auto-tuning PID controller is designed for MFS control. • The MIMO-ANFIS and PSO based optimal control is realized. • A 27.3% improvement in the output variability of fuel cell is achieved under control.

Bearingless AC Homopolar Machine Design and Control for Distributed Flywheel Energy Storage

Science.gov (United States)

Severson, Eric Loren

The increasing ownership of electric vehicles, in-home solar and wind generation, and wider penetration of renewable energies onto the power grid has created a need for grid-based energy storage to provide energy-neutral services. These services include frequency regulation, which requires short response-times, high power ramping capabilities, and several charge cycles over the course of one day; and diurnal load-/generation-following services to offset the inherent mismatch between renewable generation and the power grid's load profile, which requires low self-discharge so that a reasonable efficiency is obtained over a 24 hour storage interval. To realize the maximum benefits of energy storage, the technology should be modular and have minimum geographic constraints, so that it is easily scalable according to local demands. Furthermore, the technology must be economically viable to participate in the energy markets. There is currently no storage technology that is able to simultaneously meet all of these needs. This dissertation focuses on developing a new energy storage device based on flywheel technology to meet these needs. It is shown that the bearingless ac homopolar machine can be used to overcome key obstacles in flywheel technology, namely: unacceptable self-discharge and overall system cost and complexity. Bearingless machines combine the functionality of a magnetic bearing and a motor/generator into a single electromechanical device. Design of these machines is particularly challenging due to cross-coupling effects and trade-offs between motor and magnetic bearing capabilities. The bearingless ac homopolar machine adds to these design challenges due to its 3D flux paths requiring computationally expensive 3D finite element analysis. At the time this dissertation was started, bearingless ac homopolar machines were a highly immature technology. This dissertation advances the state-of-the-art of these machines through research contributions in the areas of

Flywheels for Low-Speed Kinetic Energy Storage Systems

International Nuclear Information System (INIS)

Portnov, G.; Cruz, I.; Arias, F.; Fiffe, R. P.

2003-01-01

A brief overview of different steel disc-type flywheels is presented. It contents the analysis of relationship between stress-state and kinetic energy of rotating body, comparison of the main characteristics of flywheels and description of their optimization procedures. It is shown that pro files of the discs calculated on a basis of plane stress-state assumption may be considered only as a starting point for its further improvement using 3-D approach. The aim of the review is to provide a designer for a insight into problem of shaping of steel flywheels. (Author) 19 refs

The calculation of energy storage flywheels of fiber composites with electric energy converter

Energy Technology Data Exchange (ETDEWEB)

Canders, W R

1982-01-01

The computation and the design of energy storage flywheels with electromechanical energy converters are considered in the present study. The most important stress parameters for flywheels of unidirectional laminate are determined, and criteria for the dimensioning of the flywheel are presented, taking into account centrifugal and compressive stresses. The required high speed of the flywheel is the dominating factor, which has to be considered also in the design of the driving engine for the storage device. The computation of the design characteristics of an outside-rotor motor with permanent-magnet excitation as an integral component of the storage device is discussed. The significance of the obtained results is illustrated with the aid of design examples and an application example in the area of vehicular technology.

Skating crossovers on a motorized flywheel: a preliminary experimental design to test effect on speed and on crossovers.

Science.gov (United States)

Smith, Aynsley M; Krause, David A; Stuart, Michael J; Montelpare, William J; Sorenson, Matthew C; Link, Andrew A; Gaz, Daniel V; Twardowski, Casey P; Larson, Dirk R; Stuart, Michael B

2013-12-01

Ice hockey requires frequent skater crossovers to execute turns. Our investigation aimed to determine the effectiveness of training crossovers on a motorized, polyethylene high-resistance flywheel. We hypothesized that high school hockey players training on the flywheel would perform as well as their peers training on ice. Participants were 23 male high-school hockey players (age 15-19 years). The study used an experimental prospective design to compare players who trained for 9 sessions on the 22-foot flywheel with players who trained for 9 sessions on a similarly sized on-ice circle. Both groups were compared with control subjects who were randomly selected from the same participant pool as those training on ice. All players were tested before and after their 3-week training regimens, and control subjects were asked to not practice crossovers between testing. Group 1 trained in a hockey training facility housing the flywheel, and group 2 trained in the ice hockey arena where testing occurred. Primary outcome measures tested in both directions were: (a) speed (time in seconds) required to skate crossovers for 3 laps of a marked face-off circle, (b) cadence of skating crossovers on the similarly sized circles, and (c) a repeat interval speed test, which measures anaerobic power. No significant changes were found between groups in on-ice testing before and after training. Among the group 1 players, 7 of 8 believed they benefited from flywheel training. Group 2 players, who trained on ice, did not improve performance significantly over group 1 players. Despite the fact that no significant on-ice changes in performance were observed in objective measures, players who trained on the flywheel subjectively reported that the flywheel is an effective cost-effective alternative to training on ice. This is a relevant finding when placed in context with limited availability of on-ice training.

Flywheel Charge/Discharge Control Developed

Science.gov (United States)

Beach, Raymond.F.; Kenny, Barbara H.

2001-01-01

A control algorithm developed at the NASA Glenn Research Center will allow a flywheel energy storage system to interface with the electrical bus of a space power system. The controller allows the flywheel to operate in both charge and discharge modes. Charge mode is used to store additional energy generated by the solar arrays on the spacecraft during insolation. During charge mode, the flywheel spins up to store the additional electrical energy as rotational mechanical energy. Discharge mode is used during eclipse when the flywheel provides the power to the spacecraft. During discharge mode, the flywheel spins down to release the stored rotational energy.

Advantage of superconducting bearing in a commercial flywheel system

Energy Technology Data Exchange (ETDEWEB)

Viznichenko, R; Velichko, A V; Hong, Z; Coombs, T A [Department of Engineering, University of Cambridge, Cambridge CB2 1PZ (United Kingdom)], E-mail: tac1000@cam.ac.uk

2008-02-01

The use of a superconducting magnetic bearing in an Urenco Power Technologies (UPT) 100kW flywheel is being studied. The dynamics of a conventional flywheel energy storage system have been studied at low frequencies. We show that the main design consideration is overcoming drag friction losses and parasitic resonances. We propose an original superconducting magnetic bearing design and improved cryogenic motor cooling to increase stability and decrease energy losses in the system.

Flywheel Energy Storage for Automotive Applications

Directory of Open Access Journals (Sweden)

Magnus Hedlund

2015-09-01

Full Text Available A review of flywheel energy storage technology was made, with a special focus on the progress in automotive applications. We found that there are at least 26 university research groups and 27 companies contributing to flywheel technology development. Flywheels are seen to excel in high-power applications, placing them closer in functionality to supercapacitors than to batteries. Examples of flywheels optimized for vehicular applications were found with a specific power of 5.5 kW/kg and a specific energy of 3.5 Wh/kg. Another flywheel system had 3.15 kW/kg and 6.4 Wh/kg, which can be compared to a state-of-the-art supercapacitor vehicular system with 1.7 kW/kg and 2.3 Wh/kg, respectively. Flywheel energy storage is reaching maturity, with 500 flywheel power buffer systems being deployed for London buses (resulting in fuel savings of over 20%, 400 flywheels in operation for grid frequency regulation and many hundreds more installed for uninterruptible power supply (UPS applications. The industry estimates the mass-production cost of a specific consumer-car flywheel system to be 2000 USD. For regular cars, this system has been shown to save 35% fuel in the U.S. Federal Test Procedure (FTP drive cycle.

Pump Coastdown with the Submerged Flywheel

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hyun-Gi; Seo, KyoungWoo; Kim, Seong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Many research reactors are generally designed as open pool types in consideration of the heat removal of the nuclear fuels, reactor operation and accessibility. Reactor structure assembly is generally placed at the pool bottom as shown in Fig. 1. Primary cooling system pump circulates the coolant from the reactor structure to the heat exchanger in order to continuously remove the heat generated from the reactor core in the research reactor as shown in Fig. 1. The secondary cooling system releases the transferred heat to the atmosphere by the cooling tower. Coastdown flow rate of the primary cooling system pump with the submerged flywheel are calculated analytically in case of the accident situation. Coastdown flow rate is maintained until almost 80 sec when the pump stops normally. But, coastdown flow rate is rapidly decreased when the flywheel is submerged because of the friction load on the flywheel surface.

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"

Flywheel and power unit

Energy Technology Data Exchange (ETDEWEB)

Seeley, R.W.

1992-10-28

A power unit, e.g. for an electrically driven vehicle, incorporates a flywheel for storing kinetic energy and a battery for storing electrical energy. The battery is incorporated as a substantial part of the rotating mass of the flywheel. Preferably the unit further includes an electrical machine being a motor or generator or machine operable either as a motor or a generator for transferring energy between the battery and the flywheel and/or for the input or output of rotary energy therefrom or thereto. The motor may be used for powering the flywheel and may also operate in a regenerative mode for recharging the unit on de-acceleration of the vehicle. The unit of the invention may also be utilized as an electrical stored power source, e.g. wind or water driven. (author)

Application of flywheel energy storage for heavy haul locomotives

International Nuclear Information System (INIS)

Spiryagin, Maksym; Wolfs, Peter; Szanto, Frank; Sun, Yan Quan; Cole, Colin; Nielsen, Dwayne

2015-01-01

Highlights: • A novel design for heavy haul locomotive equipped with a flywheel energy storage system is proposed. • The integrated intelligent traction control system was developed. • A flywheel energy storage system has been tested through a simulation process. • The developed hybrid system was verified using an existing heavy haul railway route. • Fuel efficiency analysis confirms advantages of the hybrid design. - Abstract: At the present time, trains in heavy haul operations are typically hauled by several diesel-electric locomotives coupled in a multiple unit. This paper studies the case of a typical consist of three Co–Co diesel-electric locomotives, and considers replacing one unit with an alternative version, with the same design parameters, except that the diesel-electric plant is replaced with flywheel energy storage equipment. The intelligent traction and energy control system installed in this unit is integrated into the multiple-unit control to allow redistribution of the power between all units. In order to verify the proposed design, a three-stage investigation has been performed as described in this paper. The initial stage studies a possible configuration of the flywheel energy storage system by detailed modelling of the proposed intelligent traction and energy control system. The second stage includes the investigation and estimation of possible energy flows using a longitudinal train dynamics simulation. The final stage compares the conventional and the proposed locomotive configurations considering two parameters: fuel efficiency and emissions reduction.

Stationary flywheel energy storage

Energy Technology Data Exchange (ETDEWEB)

Gilhaus, A; Hau, E; Gassner, G; Huss, G; Schauberger, H

1981-01-01

The aim of this system study is to find out industrial applications of stationary flywheel energy accumulators. The economic value for the consumer and the effects on the power supply grid are investigated. Up to now, stationary flywheel energy accumulators have only been used in a small range. The main reason for thinking of the application in a wider range was the hope that those could be used economically for lowering the maximum output demand of the power supply grid. The possible savings in energy costs, however, proved to be too small for paying back the investment costs. Further benefits are necessary for advantageous application. As to overall economy, compensation of short time maximum power output seems to be more favorable at the power stations. An additional possibility for energy storage by flywheels is given where otherwise lost energy can be used effectively, according to the successful brake energy storage in vehicles. Under this aspect the future use of flywheels in wind-power-plants seems to be promising. Attractive savings of energy can be obtained by introducing modern flywheel technology for emergency power supply units which are employed for instance in telecommunication systems. Especially the application for emergency power supply, in power stations and in combustion with wind energy converters need further investigation.

Improved flywheel materials :

Energy Technology Data Exchange (ETDEWEB)

Boyle, Timothy J.; Bell, Nelson S; Ehlen, Mark Andrew; Anderson, Benjamin John; Miller, William Kenneth

2013-09-01

As alternative energy generating devices (i.e., solar, wind, etc) are added onto the electrical energy grid (AC grid), irregularities in the available electricity due to natural occurrences (i.e., clouds reducing solar input or wind burst increasing wind powered turbines) will be dramatically increased. Due to their almost instantaneous response, modern flywheel-based energy storage devices can act a mechanical mechanism to regulate the AC grid; however, improved spin speeds will be required to meet the necessary energy levels to balance these green energy variances. Focusing on composite flywheels, we have investigated methods for improving the spin speeds based on materials needs. The so-called composite flywheels are composed of carbon fiber (C-fiber), glass fiber, and a glue (resin) to hold them together. For this effort, we have focused on the addition of fillers to the resin in order to improve its properties. Based on the high loads required for standard meso-sized fillers, this project investigated the utility of ceramic nanofillers since they can be added at very low load levels due to their high surface area. The impact that TiO2 nanowires had on the final strength of the flywheel material was determined by a three-point-bend test. The results of the introduction of nanomaterials demonstrated an increase in strength of the flywheels C-fiber-resin moiety, with an upper limit of a 30% increase being reported. An analysis of the economic impact concerning the utilization of the nanowires was undertaken and after accounting for new-technology and additional production costs, return on improved-nanocomposite investment was approximated at 4-6% per year over the 20-year expected service life. Further, it was determined based on the 30% improvement in strength, this change may enable a 20-30% reduction in flywheel energy storage cost ($/kW-h).

Modelling and optimization of a permanent-magnet machine in a flywheel

NARCIS (Netherlands)

Holm, S.R.

2003-01-01

This thesis describes the derivation of an analytical model for the design and optimization of a permanent-magnet machine for use in an energy storage flywheel. A prototype of this flywheel is to be used as the peak-power unit in a hybrid electric city bus. The thesis starts by showing the

Concept of a modified flywheel for megajoule storage and pulse conditioning

International Nuclear Information System (INIS)

Leung, T.T.

1991-01-01

This paper introduces the concept of a flywheel with a variable moment of inertia for electromagnetic launch (EML). A flywheel is among the best energy density storage devices. The modified flywheel will further improve upon the energy density and efficiency. Coupled to a pulse-duty generator, it could produce a near-square pulse or other desirable pulse shapes. The mount of energy, its rate, and its switching all could be controlled prior to electric energy conversion. The modified flywheel is structured with masses movable along radial paths. Potential energy is stored with respect to mass position and kinetic energy with respect to spin. This mass positioning provides a means to control the rate of energy discharge. Control with spring-loaded weight--the design presented here--would have near constant spin output

Flywheels Would Compensate for Rotor Imbalance

Science.gov (United States)

Hrastar, J. A. S.

1982-01-01

Spinning flywheels within rotor can null imbalance forces in rotor. Flywheels axes are perpendicular to each other and to rotor axis. Feedback signals from accelerometers or strain gages in platform control flywheel speeds and rotation directions. Concept should be useful for compensating rotating bodies on Earth. For example, may be applied to large industrial centrifuge, particularly if balance changes during operation.

TESTING THE HYPOTHESIS THAT METHANOL MASER RINGS TRACE CIRCUMSTELLAR DISKS: HIGH-RESOLUTION NEAR-INFRARED AND MID-INFRARED IMAGING

International Nuclear Information System (INIS)

De Buizer, James M.; Bartkiewicz, Anna; Szymczak, Marian

2012-01-01

Milliarcsecond very long baseline interferometry maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around forming high-mass stars. We aimed to test this hypothesis by imaging these regions in the near- and mid-infrared at high spatial resolution and compare the observed emission to the expected infrared morphologies as inferred from the geometries of the maser rings. In the near-infrared we used the Gemini North adaptive optics system of ALTAIR/NIRI, while in the mid-infrared we used the combination of the Gemini South instrument T-ReCS and super-resolution techniques. Resultant images had a resolution of ∼150 mas in both the near-infrared and mid-infrared. We discuss the expected distribution of circumstellar material around young and massive accreting (proto)stars and what infrared emission geometries would be expected for the different maser ring orientations under the assumption that the masers are coming from within circumstellar disks. Based upon the observed infrared emission geometries for the four targets in our sample and the results of spectral energy distribution modeling of the massive young stellar objects associated with the maser rings, we do not find compelling evidence in support of the hypothesis that methanol masers rings reside in circumstellar disks.

Experimental Evaluation of Superconductor Flywheel Energy Storage System with Hybrid Type Active Magnetic Bearing

International Nuclear Information System (INIS)

Lee, J. P.; Kim, H. G.; Han, S. C.

2012-01-01

In this paper, we designed Active Magnetic Bearing (AMB) for large scale Superconductor Flywheel Energy Storage System (SFESS) and PD controller for AMB. And we experimentally evaluated SFESS including hybrid type AMB. The radial AMB was designed to provide force slew rate that was sufficient for the unbalance disturbances at the maximum operating speed. The thrust AMB is a hybrid type where a permanent magnet carries the weight of the flywheel and an electromagnetic actuator generates the dynamic control force. We evaluated the design performance of the manufactured AMB through comparison of FEM analysis and the results of experimental force measurement. In order to obtain gains of PD controller and design a notch filter, the system identification was performed through measuring frequency response including dynamics for the AMBs, a power amp and a sensor using a sine swept test method after levitating the flywheel. Through measuring the current input of the AMBs and the orbit of a flywheel according to rotational speed, we verified excellent control performance of the AMBs with small amount current for the large scale SFESS.

Report on results 1998. Research and development on high-temperature superconducting flywheel power storage (system design/evaluation (comparative assessment/information collection)); 1998 nendo seika hokokusho. Koon chodendo flywheel denryoku chozo kenkyu kaihatsu (system sekkei, hyoka (hikaku kento, joho shushu))

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

For the purpose of evaluating the basic characteristics of high-temperature superconducting magnetic bearings (SBM), a system model is designed, experimentally manufactured and tested, which is embodied in the design/evaluation of a large-scale system, with an investigation carried out for the introduction of the system into an electrical power system. In this framework, an examination and research were conducted for the system design technology on which each component technology in the system structure can be applied consistently in the system. In the comparative assessment of various flywheel power storage systems, the specifications and achievements were compared in the component elements of the flywheel systems developed in Europe, America and Japan through the literature studies and the field survey, with examination performed towards the future development. As a result, it was found that, in America, bearings were all SMB's without control. Boeing's objective for the development is 10kWh or so in view of convenience for transportation and is prone to arrange it in numbers. Further, investigations were made in literature and documents on the domestic and international trend of development of high-temperature superconducting flywheel systems, elucidating the details of the development. (NEDO)

Multi-cell disk-and-ring tapered structure for compact RF linacs

Energy Technology Data Exchange (ETDEWEB)

Smirnov, A.V.; Boucher, S.; Kutsaev, S. [RadiaBeam Systems LLC, 1713 Stewart Street, Santa Monica, CA 90404, US (United States); Hartzell, J. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); Savin, E. [RadiaBeam Technologies, LLC, 1717 Stewart Street, Santa Monica, CA 90404, US (United States); National Research Nuclear University “MEPhI”, Moscow 115409 (Russian Federation)

2016-09-11

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

Multi-cell disk-and-ring tapered structure for compact RF linacs

International Nuclear Information System (INIS)

Smirnov, A.V.; Boucher, S.; Kutsaev, S.; Hartzell, J.; Savin, E.

2016-01-01

A tubular disk-and-ring, tapered accelerating structure for small electron linacs and MicroLinacs is considered. It consists of metal and dielectric elements inserted into a metallic tube to eliminate multi-cell, multi-step brazing. The structure enables a wide range of phase velocities (including non-relativistic), a wide bandwidth allowing large number of cells (for standing wave mode) or short filling time (for traveling wave mode), combination of compensated and purely π-mode cells, alternative periodic focusing built-in to the RF structure (the disks), and combining of RF and vacuum windows. RF and accelerating performance of such a long structure having up to four dozens cells is analyzed. Some of beam dynamics, thermal, and vacuum aspects of the structure and MicroLinac performance are considered as well.

On the Formation of Multiple Concentric Rings and Gaps in Protoplanetary Disks

Science.gov (United States)

Bae, Jaehan; Zhu, Zhaohuan; Hartmann, Lee

2017-12-01

As spiral waves driven by a planet in a gaseous disk steepen into a shock, they deposit angular momentum, opening a gap in the disk. This has been well studied using both linear theory and numerical simulations, but so far only for the primary spiral arm: the one directly attached to the planet. Using 2D hydrodynamic simulations, we show that the secondary and tertiary arms driven by a planet can also open gaps as they steepen into shocks. The depths of the secondary/tertiary gaps in surface density grow with time in a low-viscosity disk (α =5× {10}-5), so even low-mass planets (e.g., super-Earth or mini-Neptune-mass) embedded in the disk can open multiple observable gaps, provided that sufficient time has passed. Applying our results to the HL Tau disk, we show that a single 30 Earth-mass planet embedded in the ring at 68.8 au (B5) can reasonably well reproduce the positions of the two major gaps at 13.2 and 32.3 au (D1 and D2), and roughly reproduce two other major gaps at 64.2 and 74.7 au (D5 and D6) seen in the mm continuum. The positions of secondary/tertiary gaps are found to be sensitive to the planetary mass and the disk temperature profile, so with accurate observational measurements of the temperature structure, the positions of multiple gaps can be used to constrain the mass of the planet. We also comment on the gaps seen in the TW Hya and HD 163296 disk.

Flywheel in an all-electric propulsion system

Energy Technology Data Exchange (ETDEWEB)

Lundin, Johan

2011-07-01

Energy storage is a crucial condition for both transportation purposes and for the use of electricity. Flywheels can be used as actual energy storage but also as power handling device. Their high power capacity compared to other means of storing electric energy makes them very convenient for smoothing power transients. These occur frequently in vehicles but also in the electric grid. In both these areas there is a lot to gain by reducing the power transients and irregularities. The research conducted at Uppsala Univ. and described in this thesis is focused on an all-electric propulsion system based on an electric flywheel with double stator windings. The flywheel is inserted in between the main energy storage (assumed to be a battery) and the traction motor in an electric vehicle. This system has been evaluated by simulations in a Matlab model, comparing two otherwise identical drivelines, one with and one without a flywheel. The flywheel is shown to have several advantages for an all-electric propulsion system for a vehicle. The maximum power from the battery decreases more than ten times as the flywheel absorbs and supplies all the high power fluxes occurring at acceleration and braking. The battery delivers a low and almost constant power to the flywheel. The amount of batteries needed de- creases whereas the battery lifetime and efficiency increases. Another benefit the flywheel configuration brings is a higher energy efficiency and hence less need for cooling. The model has also been used to evaluate the flywheel functionality for an electric grid application. The power from renewable intermittent energy sources such as wave, wind and current power can be smoothened by the fly- wheel, making these energy sources more efficient and thereby competitive with a remaining high power quality in the electric grid

Superconducting bearings for flywheel applications

Energy Technology Data Exchange (ETDEWEB)

Abrahamsen, Asger Bech

2001-05-01

A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found on the applications of superconducting bearings in flywheels. (au)

A Motor/Generator for Flywheel Energy Storage System Levitated by Bulk Superconductor

Energy Technology Data Exchange (ETDEWEB)

Koh, C.S.; Yeon, J.U.; Jeoung, H.M.; Choi, J.H. [Chungbuk National University (Korea); Lee, H.J; Hong, G.W. [Korea Atomic Energy Research Institute (Korea)

2000-06-01

The energy storage systems are being widely researched for the high quality of the electric power. The FES(flywheel energy storage system)is especially, on the center of the research because it does not make any pollution and its life is long. The FES converts the electrical energy into the mechanical kinetic energy of the flywheel and reconverts the mechanical energy into the electrical energy, In order to store as much energy as possible, the flywheel is supposed to be rotated with very high speed. The motor/generator of the FES should be high efficient at high speed, and generate constant torque with respect to the rotation. In this paper, a motor/generator employing a Halbach array of permanent magnets is designed and constructed to meet the requirements, and its characteristics are examined. The magnetic field is analysed by using the magnetic surface charge method. The armature winding is designed for the harmonic components to be minimized by using the FFT. The sinusoidal currents for the motor driving are generated by the hysteresis current controller. A sample superconducting flywheel energy storage system is constructed with a duralumin flywheel which has a maximum rotating speed of 40,000[rpm] and a stored energy of 240[Wh] and its validity is examined through the experiment. (author). 15 refs., 17 figs., 2 tabs.

A coaxial ring-sidearm power extraction design

International Nuclear Information System (INIS)

Ben-Menahem, S.; Yu, D.

1996-01-01

We report a successful klystron power extraction design, in which a TEM coaxial mode is transmitted into TE10 mode of a WR90 rectangular waveguide at 11.42 GHz, with very little TEM reflection and almost vanishing asymmetric (TEM → TE11, or monopole to dipole) reflectance. Our coupler consists of a ring (disk) around the coaxial waveguide, and a coax-WR90 sidearm junction. The methods used in the design are numerical simulation, performed on the MAFIA3 T3 time- domain module and on the High Frequency Structure Simulator, and analytical treatment to guide the numerical runs. The demerit parameters (dipole reflectance and TEM reflection) can be reduced as much as desired (to zero in principle), the only limitation being computer run time and memory. Results are accurate to a few percent

Research on Adaptive Dual-Mode Switch Control Strategy for Vehicle Maglev Flywheel Battery

Directory of Open Access Journals (Sweden)

Hui Gao

2015-01-01

Full Text Available Because of the jamming signal is real-time changeable and control algorithm cannot timely tracking control flywheel rotor, this paper takes vehicle maglev flywheel battery as the research object. One kind of dual-model control strategy is developed based on the analysis of the vibration response impact of the flywheel battery control system. In view of the complex foundation vibration problems of electric vehicles, the nonlinear dynamic simulation model of vehicle maglev flywheel battery is solved. Through analyzing the nonlinear vibration response characteristics, one kind of dual-mode adaptive hybrid control strategy based on H∞ control and unbalance displacement feed-forward compensation control is presented and a real-time switch controller is designed. The reliable hybrid control is implemented, and the stability in the process of real-time switch is solved. The results of this project can provide important basic theory support for the research of vehicle maglev flywheel battery control system.

The influence of flywheel micro vibration on space camera and vibration suppression

Science.gov (United States)

Li, Lin; Tan, Luyang; Kong, Lin; Wang, Dong; Yang, Hongbo

2018-02-01

Studied the impact of flywheel micro vibration on a high resolution optical satellite that space-borne integrated. By testing the flywheel micro vibration with six-component test bench, the flywheel disturbance data is acquired. The finite element model of the satellite was established and the unit force/torque were applied at the flywheel mounting position to obtain the micro vibration data of the camera. Integrated analysis of the data of the two parts showed that the influence of flywheel micro vibration on the camera is mainly concentrated around 60-80 Hz and 170-230 Hz, the largest angular displacement of the secondary mirror along the optical axis direction is 0.04″ and the maximum angular displacement vertical to optical axis is 0.032″. After the design and installation of vibration isolator, the maximum angular displacement of the secondary mirror is 0.011″, the decay rate of root mean square value of the angular displacement is more than 50% and the maximum is 96.78%. The whole satellite was suspended to simulate the boundary condition on orbit; the imaging experiment results show that the image motion caused by the flywheel micro vibrationis less than 0.1 pixel after installing the vibration isolator.

Flywheel-battery hydrid: a new concept for vehicle propulsion

International Nuclear Information System (INIS)

Anon.

1976-01-01

A new concept was examined for powering the automobile: a flywheel-battery hybrid that can be developed for near-term use from currently available lead-acid batteries and state-of-the-art flywheel designs. To illustrate the concept, a calculation is given of the range and performance of the hybrid power system in a typical commute vehicle, and the results are compared to the measured range and performance of an all-battery vehicle. This comparison shows improved performance and a twofold urban-range increase for the hybrid over the all-battery power system

Report on results 1998. Research and development on high-temperature superconducting flywheel power storage (system design/evaluation (comparative assessment/information collection)); 1998 nendo seika hokokusho. Koon chodendo flywheel denryoku chozo kenkyu kaihatsu (system sekkei, hyoka (hikaku kento, joho shushu))

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

For the purpose of evaluating the basic characteristics of high-temperature superconducting magnetic bearings (SBM), a system model is designed, experimentally manufactured and tested, which is embodied in the design/evaluation of a large-scale system, with an investigation carried out for the introduction of the system into an electrical power system. In this framework, an examination and research were conducted for the system design technology on which each component technology in the system structure can be applied consistently in the system. In the comparative assessment of various flywheel power storage systems, the specifications and achievements were compared in the component elements of the flywheel systems developed in Europe, America and Japan through the literature studies and the field survey, with examination performed towards the future development. As a result, it was found that, in America, bearings were all SMB's without control. Boeing's objective for the development is 10kWh or so in view of convenience for transportation and is prone to arrange it in numbers. Further, investigations were made in literature and documents on the domestic and international trend of development of high-temperature superconducting flywheel systems, elucidating the details of the development. (NEDO)

Terfenol-D/Pb(Zr,Ti)O{sub 3} disk-ring multiferroic heterostructures coupled through normal stresses

Energy Technology Data Exchange (ETDEWEB)

Li, Lei; Chen, Xiang Ming [Zhejiang University, Laboratory of Dielectric Materials, Department of Materials Science and Engineering, Hangzhou (China)

2010-03-15

Disk-ring multiferroic heterostructures composed of Terfenol-D and Pb(Zr,Ti)O{sub 3} (PZT) were prepared and characterized, for which the ferromagnetic and ferroelectric phases were coupled through normal stresses instead of the shear stresses that acted in most of the previous multiferroic heterostructures. High low-frequency magnetoelectric coefficients of 0.10-0.75 V cm{sup -1} Oe{sup -1} were attained for the disk-ring heterostructures, which indicated the strong magnetoelectric coupling. Moreover, a symmetrical resonant peak was observed for dE{sub 3}/dH{sub 3} in the frequency range of 1-200 kHz, while another weak peak with asymmetrical shape also existed at a lower frequency for dE{sub 3}/dH{sub 1}, which was due to the combination of two vibration modes. (orig.)

A Resolved and Asymmetric Ring of PAHs within the Young Circumstellar Disk of IRS 48

Energy Technology Data Exchange (ETDEWEB)

Schworer, Guillaume; Lacour, Sylvestre; Du Foresto, Vincent Coudé [LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité (France); Huélamo, Nuria [Dpto. Astrofísica, Centro de Astrobiología (INTA-CSIC), ESAC Campus, P.O. Box 78, E-28691, Villanueva de la Cañada (Spain); Pinte, Christophe; Chauvin, Gaël [Univ. Grenoble Alpes, IPAG, F-38000 Grenoble, France CNRS, IPAG, F-38000 Grenoble (France); Ehrenreich, David [Observatoire de l’Université de Genève, 51 chemin des Maillettes, 1290 Versoix (Switzerland); Girard, Julien [European Southern Observatory, Alonso de Cordova 3107, Casilla 19001 Vitacura, Santiago 19 (Chile); Tuthill, Peter [Sydney Institute for Astronomy, School of Physics, The University of Sydney, NSW 2006 (Australia)

2017-06-20

For one decade, the spectral type and age of the ρ Oph object IRS-48 were subject to debate and mystery. Modeling its disk with mid-infrared to millimeter observations led to various explanations to account for the complex intricacy of dust holes and gas-depleted regions. We present multi-epoch high-angular-resolution interferometric near-infrared data of spatially resolved emissions in the first 15 au of IRS-48, known to have very strong polycyclic aromatic hydrocarbon (PAH) emissions within this dust-depleted region. We make use of new Sparse-Aperture-Masking data to instruct a revised radiative-transfer model, where spectral energy distribution fluxes and interferometry are jointly fitted. Neutral and ionized PAH, very small grains (VSG), and classical silicates are incorporated into the model; new stellar parameters and extinction laws are explored. A bright (42 L {sub ⊙}) and hence large (2.5 R {sub ⊙}) central star with A {sub v} = 12.5 mag and R {sub v} = 6.5 requires less near-infrared excess: the inner-most disk at ≈1 au is incompatible with the interferometric data. The revised stellar parameters place this system on a 4 Myr evolutionary track, four times younger than the previous estimations, which is in better agreement with the surrounding ρ Oph region and disk-lifetime observations. The disk-structure solution converges to a classical-grain outer disk from 55 au combined with an unsettled and fully resolved VSG and PAH ring, between 11 and 26 au. We find two overluminosities in the PAH ring at color-temperatures consistent with the radiative transfer simulations; one follows a Keplerian circular orbit at 14 au. We show a depletion of a factor of ≈5 of classical dust grains up to 0.3 mm compared to very small particles: the IRS-48 disk is nearly void of dust grains in the first 55 au. A 3.5 M {sub Jup} planet on a 40 au orbit can qualitatively explain the new disk structure.

The New Structure Design and Analysis of Energy Storage of Flywheel of Split Rotor

OpenAIRE

Peng Xu; Wei Wang; Jin Yan; Shaoyang Han

2015-01-01

The braking of the rail transit train consumes a great quantity of energy, and the thermal energy produced in the process of braking can affect the normal operation of the transit train. Thus recycling the braking energy becomes a research hotspot of urban rail train. This paper made an overall analysis of regenerative braking process, the rationale, and the main features and then put forward the optimizing the structure of the composite flywheel concept and design calculation method. This pa...

Flywheel system using wire-wound rotor

Science.gov (United States)

Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

2016-06-07

A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

Battery Recharging Issue for a Two-Power-Level Flywheel System

Directory of Open Access Journals (Sweden)

Janaína Gonçalves de Oliveira

2010-01-01

Full Text Available A novel battery recharging system for an all-electric driveline comprising a flywheel with a permanent magnet double wound synchronous machine (motor/generator is presented. The double winding enables two voltage levels and two different power levels. This topology supersedes other all-electric drivelines. The battery operates in a low-power regime supplying the average power whereas the flywheel delivers and absorbs power peaks, which are up to a higher order of magnitude. The topology presents new challenges for the power conversion system, which is the focus of this investigation. The main challenge is the control of the power flow to the battery when the vehicle is parked despite the decay of the flywheel machine voltage; which is dependent on its charge state, that is, rotational speed. The design and simulation of an unidirectional DC/DC buck/boost converter for a variable rotational speed flywheel is presented. Conventional power electronic converters are used in a new application, which can maintain a constant current or voltage on the battery side. Successful PI current control has been implemented and simulated, together with the complete closed loop system.

Circumstellar and circumplanetary disks

Science.gov (United States)

Chiang, Eugene

2000-11-01

This thesis studies disks in three astrophysical contexts: (1)protoplanetary disks; (2)the Edgeworth-Kuiper Belt; and (3)planetary rings. We derive hydrostatic, radiative equilibrium models of passive protoplanetary disks surrounding T Tauri and Herbig Ae/Be stars. Each disk is encased by an optically thin layer of superheated dust grains. This layer is responsible for up to ~70% of the disk luminosity at wavelengths between ~5 and 60 μm. The heated disk flares and absorbs more stellar radiation at a given stellocentric distance than a flat disk would. Spectral energy distributions are computed and found to compare favorably with the observed flattish infrared excesses of several young stellar objects. Spectral features from dust grains in the superheated layer appear in emission if the disk is viewed nearly face-on. We present the results of a pencil-beam survey of the Kuiper Belt using the Keck 10-m telescope. Two new objects are discovered. Data from all surveys are pooled to construct the luminosity function from mR = 20 to 27. The cumulative number of objects per square degree, Σ(surface area but the largest bodies contain most of the mass. To order-of-magnitude, 0.2 M⊕ and 1 × 1010 comet progenitors lie between 30 and 50 AU. The classical Kuiper Belt appears truncated at a distance of 50 AU. We propose that rigid precession of narrow eccentric planetary rings surrounding Uranus and Saturn is maintained by a balance of forces due to ring self- gravity, planetary oblateness, and interparticle collisions. Collisional impulses play an especially dramatic role near ring edges. Pressure-induced accelerations are maximal near edges because there (1)velocity dispersions are enhanced by resonant satellite perturbations, and (2)the surface density declines steeply. Remarkably, collisional forces felt by material in the last ~100 m of a ~10 km wide ring can increase equilibrium masses up to a factor of ~100. New ring surface densities are derived which accord with

A Static Burst Test for Composite Flywheel Rotors

Science.gov (United States)

Hartl, Stefan; Schulz, Alexander; Sima, Harald; Koch, Thomas; Kaltenbacher, Manfred

2016-06-01

High efficient and safe flywheels are an interesting technology for decentralized energy storage. To ensure all safety aspects, a static test method for a controlled initiation of a burst event for composite flywheel rotors is presented with nearly the same stress distribution as in the dynamic case, rotating with maximum speed. In addition to failure prediction using different maximum stress criteria and a safety factor, a set of tensile and compressive tests is carried out to identify the parameters of the used carbon fiber reinforced plastics (CFRP) material. The static finite element (FE) simulation results of the flywheel static burst test (FSBT) compare well to the quasistatic FE-simulation results of the flywheel rotor using inertia loads. Furthermore, it is demonstrated that the presented method is a very good controllable and observable possibility to test a high speed flywheel energy storage system (FESS) rotor in a static way. Thereby, a much more expensive and dangerous dynamic spin up test with possible uncertainties can be substituted.

Ultrasonic Resonance Spectroscopy of Composite Rims for Flywheel Rotors

Science.gov (United States)

Harmon, Laura M.; Baaklini, George Y.

2002-01-01

Flywheel energy storage devices comprising multilayered composite rotor systems are being studied extensively for utilization in the International Space Station. These composite material systems were investigated with a recently developed ultrasonic resonance spectroscopy technique. The ultrasonic system employs a continuous swept-sine waveform and performs a fast Fourier transform (FFT) on the frequency response spectrum. In addition, the system is capable of equalizing the amount of energy at each frequency. Equalization of the frequency spectrum, along with interpretation of the second FFT, aids in the evaluation of the fundamental frequency. The frequency responses from multilayered material samples, with and without known defects, were analyzed to assess the capabilities and limitations of this nondestructive evaluation technique for material characterization and defect detection. Amplitude and frequency changes were studied from ultrasonic responses of thick composite rings and a multiring composite rim. A composite ring varying in thickness was evaluated to investigate the full thickness resonance. The frequency response characteristics from naturally occurring voids in a composite ring were investigated. Ultrasonic responses were compared from regions with and without machined voids in a composite ring and a multiring composite rim. Finally, ultrasonic responses from the multiring composite rim were compared before and after proof spin testing to 63,000 rpm.

RINGED SUBSTRUCTURE AND A GAP AT 1 au IN THE NEAREST PROTOPLANETARY DISK

Energy Technology Data Exchange (ETDEWEB)

Andrews, Sean M.; Wilner, David J.; Bai, Xue-Ning; Öberg, Karin I.; Ricci, Luca [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Zhu, Zhaohuan [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Birnstiel, Tilman [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Carpenter, John M. [Joint ALMA Observatory (JAO), Alonso de Cordova 3107, Vitacura-Santiago de Chile (Chile); Pérez, Laura M. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Hughes, A. Meredith [Department of Astronomy, Wesleyan University, Van Vleck Observatory, 96 Foss Hill Drive, Middletown, CT 06457 (United States); Isella, Andrea, E-mail: sandrews@cfa.harvard.edu [Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, TX 77005 (United States)

2016-04-01

We present long baseline Atacama Large Millimeter/submillimeter Array (ALMA) observations of the 870 μm continuum emission from the nearest gas-rich protoplanetary disk, around TW Hya, that trace millimeter-sized particles down to spatial scales as small as 1 au (20 mas). These data reveal a series of concentric ring-shaped substructures in the form of bright zones and narrow dark annuli (1–6 au) with modest contrasts (5%–30%). We associate these features with concentrations of solids that have had their inward radial drift slowed or stopped, presumably at local gas pressure maxima. No significant non-axisymmetric structures are detected. Some of the observed features occur near temperatures that may be associated with the condensation fronts of major volatile species, but the relatively small brightness contrasts may also be a consequence of magnetized disk evolution (the so-called zonal flows). Other features, particularly a narrow dark annulus located only 1 au from the star, could indicate interactions between the disk and young planets. These data signal that ordered substructures on ∼au scales can be common, fundamental factors in disk evolution and that high-resolution microwave imaging can help characterize them during the epoch of planet formation.

Analisa Variable Moment of Inertia (VMI Flywheel pada Hydro-Shock Absorber Kendaraan

Directory of Open Access Journals (Sweden)

Hasbulah Zarkasy

2017-01-01

Full Text Available Flywheel selama ini dimanfaatkan untuk menyimpan energi mekanik pada mesin, membuat mesin berputar dengan lebih lembut. Prinsip kerja dari flywheel adalah dengan memanfaatkan momen inersia. Baru-baru ini dilakukan penelitian lebih lanjut mengenai pemanfaatan dari flywheel, yakni pada sistem suspense, akan tetapi selama ini penelitian yang dilakukan terbatas pada flywheel dengan momen inersia yang konstan (Constant Moment of Inertia. Kali ini akan dilakukan penelitian mengenai Variable Moment of Inertia Flywhel atau dengan kata lain flywheel yang momen inersianya berubah-ubah. Flywheel ini terdiri dari dua bagian utama, yakni flywheel berongga dan slider yang dapat bergerak bebas di sepanjang guide track. Percobaan bertujuan untuk mengetahui bagaimana karakteristik gaya redam dari VMI Flywheel. Juga akan dianalisa seperti apa respon dinamis dari slider selama flywheel berputar. Selain itu respon dinamis kendaraan saat VMI Flywheel ini dipasangkan juga dianalisa. Hasil yang didapat menunjukkan bahwa variasi massa slider berpengaruh terhadap gaya redam yang dihasilkan oleh VMI Flywheel. Semakin besar massa slider, gaya redam yang muncul juga semakin besar. Faktor frekuensi input juga berpengaruh, sebab semakin besar frekuensi input yang pada shock absorber, gaya redam yang timbul juga membesar. Perpindahan yang dialami oleh slider juga tergantung pada jenis massa slider tersebut. Semakin besar massa slider, perpindahan yang dialami juga akan semakin besar. Performa VMI Flywheel secara umum pada frekuensi rendah. Sedangkan pada frekuensi tinggi, performa VMI Flywheel cenderung tidak bagus dan menyebabkan kendaraan tidak nyaman.

Flywheel for a 167 MVA surge power motor-generator set

International Nuclear Information System (INIS)

Mertens, H.

1975-01-01

Flywheels to be subjected to major speed fluctuations are designed on the basis of both the usual strength analysis and fracture mechanics considerations, and the testing and operating instructions have to allow for this. Appropriate test units are used to determine the fracture toughness of the material. Residual stresses are measured and extensive ultrasonic and magnetic particle tests performed to enable the permissible number of stress cycles to be predicted. The article deals with these problems by reference to the flywheel of a 167 MVA surge power motor-generator set for the Max Planck Insitute for Plasma Physics in Garching. (orig.) [de

Study of flywheel energy storage for space stations

Science.gov (United States)

Gross, S.

1984-01-01

The potential of flywheel systems for space stations using the Space Operations Center (SOC) as a point of reference is discussed. Comparisons with batteries and regenerative fuel cells are made. In the flywheel energy storage concept, energy is stored in the form of rotational kinetic energy using a spinning wheel. Energy is extracted from the flywheel using an attached electrical generator; energy is provided to spin the flywheel by a motor, which operates during sunlight using solar array power. The motor and the generator may or may not be the same device. Flywheel energy storage systems have a very good potential for use in space stations. This system can be superior to alkaline secondary batteries and regenerable fuel cells in most of the areas that are important in spacecraft applications. Of special impotance relative to batteries, are high energy density (lighter weight), longer cycle and operating life, and high efficiency which minimizes the amount of orbital makeup fuel required. In addition, flywheel systems have a long shelf life, give a precise state of charge indication, have modest thermal control needs, are capable of multiple discharges per orbit, have simple ground handling needs, and have the potential for very high discharge rate. Major disadvantages are noted.

Durability of filament-wound composite flywheel rotors

Science.gov (United States)

Koyanagi, Jun

2012-02-01

This paper predicts the durability of two types of flywheels, one assumes to fail in the radial direction and the other assumes to fail in the circumferential direction. The flywheel failing in the radial direction is a conventional filament-wound composite flywheel and the one failing in the circumferential direction is a tailor-made type. The durability of the former is predicted by Micromechanics of Failure (MMF) (Ha et al. in J. Compos. Mater. 42:1873-1875, 2008), employing time-dependent matrix strength, and that of the latter is predicted by Simultaneous Fiber Failure (SFF) (Koyanagi et al. in J. Compos. Mater. 43:1901-1914, 2009), employing identical time-dependent matrix strength. The predicted durability of the latter is much greater than that of the former, depending on the interface strength. This study suggests that a relatively weak interface is necessary for high-durability composite flywheel fabrication.

Effects of Material Properties on the Total Stored Energy of a Hybrid Flywheel Rotor

Energy Technology Data Exchange (ETDEWEB)

Ha, S.K.; Yoon, Y.B. [Hanyang University, Seoul (Korea); Han, S.C. [Korea Electric Power Research Institute, Taejon (Korea)

2000-05-01

A numerical method based on an assumption of a generalized plane strain (GPS) state is presented for calculating the stress and strength ratio distributions of the rotating composite flywheel rotor of varying material properties in the radial direction. The rotor is divided into many rings and each ring has constant material properties. All the rings are assumed to expand and have the same axial strain. A three-dimensional finite element method is then used to verify the accuracy of the present method for various height ratios and ply angles. This method gives a better solution for most of the rotors than other methods of a plane stress or plane strain state. After verification, the effects of material properties on the total stored energy (TSE) of the composite flywheel rotor are investigated. For this purpose, the material properties of the rotor, i.e., circumferential and radial Youngs moduli, ply angles and mass densities, are expressed by power functions of the radius and the rotor is analyzed. The analysis shows that TSE can be most effectively increased by changing the circumferential Youngs moduli along the radius, which amounts to over 300% of TSE of the constant material properties. The variation of ply angles along the radius can increase TSE by about 30% at most. The method of changing the mass densities along the radius could be also effective but its effects are not so noticeable in the rotor where the circumferential stiffness is properly arranged. (author). 24 refs., 7 figs.

Interaction Region Design for a Ring-Ring LHeC

CERN Document Server

Thompson, L N S; Bernard, N R; Fitterer, M; Holzer, B; Klein, M; Kostka, P

2011-01-01

tively low energy and moderately high intensity provides high luminosity TeV-scale e-p collisions at one of the LHC interaction points, running simultaneously with existing experiments. Two designs are studied; an electron ring situated in the LHC tunnel, and an electron linac. The focus of this paper is on the ring design. Designing an e-p machine presents interesting accelerator physics and design challenges, particularly when considering the interaction region. These include coupled optics, beam separation and unconventional mini-beta focusing schemes. Designs are constrained by an array of interdependent factors, including beam-beam interaction, detector dimensions and acceptance, luminosity and synchrotron radiation. Methods of addressing these complex issues are discussed. The current designs for the LHeC Ring-Ring interaction region and long straight section are presented and discussed, in the context of the project goals and design challenges encountered. Future developments and work are also discusse...

Rings of Molecular Line Emission in the Disk Orbiting the Young, Close Binary V4046 Sgr

Science.gov (United States)

Dickson-Vandervelde, Dorothy; Kastner, Joel H.; Qi, C.; Forveille, Thierry; Hily-Blant, Pierre; Oberg, Karin; Wilner, David; Andrews, Sean; Gorti, Uma; Rapson, Valerie; Sacco, Germano; Principe, David

2018-01-01

We present analysis of a suite of subarcsecond ALMA Band 6 (1.1 - 1.4 mm) molecular line images of the circumbinary, protoplanetary disk orbiting V4046 Sgr. The ~20 Myr-old V4046 Sgr system, which lies a mere ~73 pc from Earth, consists of a close (separation ~10 Rsun) pair of roughly solar-mass stars that are orbited by a gas-rich crcumbinary disk extending to ~350 AU in radius. The ALMA images reveal that the molecules CO and HCN and their isotopologues display centrally peaked surface brightness morphologies, whereas the cyanide group molecules (HC3N, CH3CN), deuterated molecules (DCN, DCO+), hydrocarbons (as traced by C2H), and potential CO ice line tracers (N2H+, and H2CO) appear as a sequence of sharp and diffuse rings of increasing radii. The characteristic sizes of these molecular emission rings, which range from ~25 to >100 AU in radius, are evident in radial emission-line surface brightness profiles extracted from the deprojected disk images. We find that emission from 13CO emission transitions from optically thin to thick within ~50 AU, whereas C18O emission remains optically thin within this radius. We summarize the insight into the physical and chemical processes within this evolved protoplanetary disk that can be obtained from comparisons of the various emission-line morphologies with each other and with that of the continuum (large-grain) emission on size scales of tens of AU.This research is supported by NASA Exoplanets program grant NNX16AB43G to RIT

Superconductor bearings, flywheels and transportation

International Nuclear Information System (INIS)

Werfel, F N; Floegel-Delor, U; Rothfeld, R; Riedel, T; Goebel, B; Wippich, D; Schirrmeister, P

2012-01-01

This paper describes the present status of high temperature superconductors (HTS) and of bulk superconducting magnet devices, their use in bearings, in flywheel energy storage systems (FESS) and linear transport magnetic levitation (Maglev) systems. We report and review the concepts of multi-seeded REBCO bulk superconductor fabrication. The multi-grain bulks increase the averaged trapped magnetic flux density up to 40% compared to single-grain assembly in large-scale applications. HTS magnetic bearings with permanent magnet (PM) excitation were studied and scaled up to maximum forces of 10 kN axially and 4.5 kN radially. We examine the technology of the high-gradient magnetic bearing concept and verify it experimentally. A large HTS bearing is tested for stabilizing a 600 kg rotor of a 5 kWh/250 kW flywheel system. The flywheel rotor tests show the requirement for additional damping. Our compact flywheel system is compared with similar HTS–FESS projects. A small-scale compact YBCO bearing with in situ Stirling cryocooler is constructed and investigated for mobile applications. Next we show a successfully developed modular linear Maglev system for magnetic train operation. Each module levitates 0.25t at 10 mm distance during one-day operation without refilling LN 2 . More than 30 vacuum cryostats containing multi-seeded YBCO blocks are fabricated and are tested now in Germany, China and Brazil.

A Shaftless Magnetically Levitated Multifunctional Spacecraft Flywheel Storage System

Science.gov (United States)

Stevens, Ken; Thornton, Richard; Clark, Tracy; Beaman, Bob G.; Dennehy, Neil; Day, John H. (Technical Monitor)

2002-01-01

Presently many types of spacecraft use a Spacecraft Attitude Control System (ACS) with momentum wheels for steering and electrochemical batteries to provide electrical power for the eclipse period of the spacecraft orbit. Future spacecraft will use Flywheels for combined use in ACS and Energy Storage. This can be done by using multiple wheels and varying the differential speed for ACS and varying the average speed for energy storage and recovery. Technology in these areas has improved since the 1990s so it is now feasible for flywheel systems to emerge from the laboratory for spacecraft use. This paper describes a new flywheel system that can be used for both ACS and energy storage. Some of the possible advantages of a flywheel system are: lower total mass and volume, higher efficiency, less thermal impact, improved satellite integration schedule and complexity, simplified satellite orbital operations, longer life with lower risk, less pointing jitter, and greater capability for high-rate slews. In short, they have the potential to enable new types of missions and provide lower cost. Two basic types of flywheel configurations are the Flywheel Energy Storage System (FESS) and the Integrated Power and Attitude Control System (IPACS).

Study of Mn dissolution from LiMn{sub 2}O{sub 4} spinel electrodes using rotating ring-disk collection experiments

Energy Technology Data Exchange (ETDEWEB)

Wang, Li-Fang; Ou, Chin-Ching; Striebel, Kathryn A.; Chen, Jenn-Shing

2003-07-01

The goal of this research was to measure Mn dissolution from a thin porous spinel LiMn{sub 2}O{sub 4} electrode by rotating ring-disk collection experiments. The amount of Mn dissolution from the spinel LiMn{sub 2}O{sub 4} electrode under various conditions was detected by potential step chronoamperometry. The concentration of dissolved Mn was found to increase with increasing cycle numbers and elevated temperature. The dissolved Mn was not dependent on disk rotation speed, which indicated that the Mn dissolution from the disk was under reaction control. The in situ monitoring of Mn dissolution from the spinel was carried out under various conditions. The ring currents exhibited maxima corresponding to the end-of-charge (EOC) and end-of-discharge (EOD), with the largest peak at EOC. The results suggest that the dissolution of Mn from spinel LiMn{sub 2}O{sub 4} occurs during charge/discharge cycling, especially in a charged state (at >4.1 V) and in a discharged state (at <3.1 V). The largest peak at EOC demonstrated that Mn dissolution took place mainly at the top of charge. At elevated temperatures, the ring cathodic currents were larger due to the increase of Mn dissolution rate.

Electromechanical characteristics of piezoelectric ceramic transformers in radial vibration composed of concentric piezoelectric ceramic disk and ring

International Nuclear Information System (INIS)

Lin, Shuyu; Hu, Jing; Fu, Zhiqiang

2013-01-01

A new type of piezoelectric ceramic transformer in radial vibration is presented. The piezoelectric transformer consists of a pairing of a concentric piezoelectric ceramic circular disk and ring. The inner piezoelectric ceramic disk is axially polarized and the outer piezoelectric ring is radially polarized. Based on the plane stress theory, the exact analytical theory for the piezoelectric transformer is developed and its electromechanical equivalent circuit is introduced. The resonance/anti-resonance frequency equations of the transformer are obtained and the relationship between the resonance/anti-resonance frequency, the effective electromechanical coupling coefficient and the geometrical dimensions of the piezoelectric transformer is analyzed. The dependency of the voltage transformation ratio on the frequency is obtained. To verify the analytical theory, a numerical method is used to simulate the electromechanical characteristics of the piezoelectric transformer. It is shown that the analytical resonance/anti-resonance frequencies are in good agreement with the numerical results. (paper)

Quadriceps muscle use in the flywheel and barbell squat.

Science.gov (United States)

Norrbrand, Lena; Tous-Fajardo, Julio; Vargas, Roberto; Tesch, Per A

2011-01-01

Resistance exercise has been proposed as an aid to counteract quadriceps muscle atrophy in astronauts during extended missions in orbit. While space authorities have advocated the squat exercise should be prescribed, no exercise system suitable for in-flight use has been validated with regard to quadriceps muscle use. We compared muscle involvement in the terrestrial "gold standard" squat using free weights and a nongravity dependent flywheel resistance exercise device designed for use in space. The subjects were 10 strength-trained men who performed 5 sets of 10 repetitions using the barbell squat (BS; 10 repetition maximum) or flywheel squat (FS; each repetition maximal), respectively. Functional magnetic resonance imaging (MRI) and surface electromyography (EMG) techniques assessed quadriceps muscle use. Exercise-induced contrast shift of MR images was measured by means of transverse relaxation time (T2). EMG root mean square (RMS) was measured during concentric (CON) and eccentric (ECC) actions and normalized to EMG RMS determined during maximal voluntary contraction. The quadriceps muscle group showed greater exercise-induced T2 increase following FS compared with BS. Among individual muscles, the rectus femoris displayed greater T2 increase with FS (+24 +/- 14%) than BS (+8 +/- 4%). Normalized quadriceps EMG showed no difference across exercise modes. Collectively, the results of this study suggest that quadriceps muscle use in the squat is comparable, if not greater, with flywheel compared with free weight resistance exercise. Data appear to provide support for use of flywheel squat resistance exercise as a countermeasures adjunct during spaceflight.

Flywheel energy storage; Schwungmassenspeicher

Energy Technology Data Exchange (ETDEWEB)

Bornemann, H.J. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany)

1996-12-31

Energy storages may be chemical systems such as batteries, thermal systems such as hot-water tanks, electromagnetic systems such as capacitors and coils, or mechanical systems such as pumped storage power systems or flywheel energy storages. In flywheel energy storages the energy is stored in the centrifugal mass in the form of kinetic energy. This energy can be converted to electricity via a motor/generator unit and made available to the consumer. The introduction of magnetic bearings has greatly enhanced the potential of flywheel energy storages. As there is no contact between the moving parts of magnetic bearings, this technology provides a means of circumventing the engineering and operational problems involved in the we of conventional bearings (ball, roller, plain, and gas bearings). The advantages of modern flywheel energy storages over conventional accumulators are an at least thousandfold longer service life, low losses during long-time storage, greater power output in the case of short-time storage, and commendable environmental benignity. (orig./HW) [Deutsch] Als Enegiespeicher kommen chemische Systeme, z.B. Batterien, thermische Systeme, z.B. Warmwassertanks, elektromagnetische Systeme, z.B. Kondensatoren und Spulen, sowie mechanische Systeme, z.B. Pumpspeicherwerke und Schwungmassenspeicher in Frage. In einem Schwungmassenspeicher wird Energie in Form von kinetischer Energie in der Schwungmasse gespeichert. Ueber eine Moter/Generator Einheit wird diese Energie in elektrischen Strom umgewandelt und dem Verbraucher zugefuehrt. Mit der Einfuehrung von magnetischen Lagern konnte die Leistungsfaehigkeit von Schwungmassenspeichern erheblich gesteigert werden. Da in einem Magnetlager keine Beruehrung zwischen sich bewegenden Teilen besteht, wird ein Grossteil der mit dem Einsatz konventioneller Lager (Kugel- und Rollenlager, Gleitlager und Gaslager) verbundenen ingenieurtechnischen und betriebstechnischen Probleme vermieden. Die Vorteile von modernen

HNC IN PROTOPLANETARY DISKS

International Nuclear Information System (INIS)

Graninger, Dawn; Öberg, Karin I.; Qi, Chunhua; Kastner, Joel

2015-01-01

The distributions and abundances of small organics in protoplanetary disks are potentially powerful probes of disk physics and chemistry. HNC is a common probe of dense interstellar regions and the target of this study. We use the Submillimeter Array (SMA) to observe HNC 3–2 toward the protoplanetary disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296. HNC is detected toward both disks, constituting the first spatially resolved observations of HNC in disks. We also present SMA observations of HCN 3–2 and IRAM 30 m observations of HCN and HNC 1–0 toward HD 163296. The disk-averaged HNC/HCN emission ratio is 0.1–0.2 toward both disks. Toward TW Hya, the HNC emission is confined to a ring. The varying HNC abundance in the TW Hya disk demonstrates that HNC chemistry is strongly linked to the disk physical structure. In particular, the inner rim of the HNC ring can be explained by efficient destruction of HNC at elevated temperatures, similar to what is observed in the ISM. However, to realize the full potential of HNC as a disk tracer requires a combination of high SNR spatially resolved observations of HNC and HCN and disk-specific HNC chemical modeling

HNC IN PROTOPLANETARY DISKS

Energy Technology Data Exchange (ETDEWEB)

Graninger, Dawn; Öberg, Karin I.; Qi, Chunhua [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Kastner, Joel, E-mail: dgraninger@cfa.harvard.edu [Center for Imaging Science, School of Physics and Astronomy, and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States)

2015-07-01

The distributions and abundances of small organics in protoplanetary disks are potentially powerful probes of disk physics and chemistry. HNC is a common probe of dense interstellar regions and the target of this study. We use the Submillimeter Array (SMA) to observe HNC 3–2 toward the protoplanetary disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296. HNC is detected toward both disks, constituting the first spatially resolved observations of HNC in disks. We also present SMA observations of HCN 3–2 and IRAM 30 m observations of HCN and HNC 1–0 toward HD 163296. The disk-averaged HNC/HCN emission ratio is 0.1–0.2 toward both disks. Toward TW Hya, the HNC emission is confined to a ring. The varying HNC abundance in the TW Hya disk demonstrates that HNC chemistry is strongly linked to the disk physical structure. In particular, the inner rim of the HNC ring can be explained by efficient destruction of HNC at elevated temperatures, similar to what is observed in the ISM. However, to realize the full potential of HNC as a disk tracer requires a combination of high SNR spatially resolved observations of HNC and HCN and disk-specific HNC chemical modeling.

Kinematics analysis of vertical magnetic suspension energy storage flywheel rotor under transient rotational speed

Science.gov (United States)

Ren, Zhengyi; Huang, Tong; Feng, Jiajia; Zhou, Yuanwei

2018-05-01

In this paper, a 600Wh vertical maglev energy storage flywheel rotor system is taken as a model. The motion equation of a rigid rotor considering the gyroscopic effect and the center of mass offset is obtained by the centroid theorem, and the experimental verification is carried out. Using the state variable method, the Matlab software was used to program and simulate the radial displacement and radial electromagnetic force of the rotor system at each speed. The results show that the established system model is in accordance with the designed 600Wh vertical maglev energy storage flywheel model. The results of the simulation analysis are helpful to further understand the dynamic nature of the flywheel rotor at different transient speeds.

Start It up: Flywheel Energy Storage Efficiency

Science.gov (United States)

Dunn, Michelle

2011-01-01

The purpose of this project was to construct and test an off-grid photovoltaic (PV) system in which the power from a solar array could be stored in a rechargeable battery and a flywheel motor generator assembly. The mechanical flywheel energy storage system would in turn effectively power a 12-volt DC appliance. The voltage and current of…

Optimal energy management for a flywheel-based hybrid vehicle

NARCIS (Netherlands)

Berkel, van K.; Hofman, T.; Vroemen, B.G.; Steinbuch, M.

2011-01-01

This paper presents the modeling and design of an optimal Energy Management Strategy (EMS) for a flywheel-based hybrid vehicle, that does not use any electrical motor/generator, or a battery, for its hybrid functionalities. The hybrid drive train consists of only low-cost components, such as a

Enhanced Control for a Direct-driven Permanent Synchronous Generator Wind-power Generation System with Flywheel Energy Storage Unit Under Unbalanced Grid Fault

DEFF Research Database (Denmark)

Yao, Jun; Zhou, Te; Hu, Weihao

2015-01-01

This article presents an enhanced control strategy for a direct-driven permanent synchronous generator based wind-power generation system with a flywheel energy storage unit. The behaviors of the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit under......, the DC-link voltage oscillations can be effectively suppressed during the unbalanced grid fault by controlling the flywheel energy storage unit. Furthermore, a proportional–integral-resonant controller is designed for the flywheel motor to eliminate the oscillations in the DC-link voltage. Finally......, the proposed coordinated control strategy for the direct-driven permanent magnet synchronous generator system with a flywheel energy storage unit has been validated by the simulation results of a 1-MW direct-driven permanent magnet synchronous generator wind power generation system with a flywheel energy...

Comparison of joint kinetics during free weight and flywheel resistance exercise.

Science.gov (United States)

Chiu, Loren Z F; Salem, George J

2006-08-01

The most common modality for resistance exercise is free weight resistance. Alternative methods of providing external resistance have been investigated, in particular for use in microgravity environments such as space flight. One alternative modality is flywheel inertial resistance, which generates resistance as a function of the mass, distribution of mass, and angular acceleration of the flywheel. The purpose of this investigation was to characterize net joint kinetics of multijoint exercises performed with a flywheel inertial resistance device in comparison to free weights. Eleven trained men and women performed the front squat, lunge, and push press on separate days with free weight or flywheel resistance, while instrumented for biomechanical analysis. Front squats performed with flywheel resistance required greater contribution of the hip and ankle, and less contribution of the knee, compared to free weight. Push presses performed with flywheel resistance had similar impulse requirements at the knee compared to free weight, but greater impulse requirement at the hip and ankle. As used in this investigation, flywheel inertial resistance increases the demand on the hip extensors and ankle plantarflexors and decreases the mechanical demand on the knee extensors for lower extremity exercises such as the front squat and lunge. Exercises involving dynamic lower and upper extremity actions, such as the push press, may benefit from flywheel inertial resistance, due to the increased mechanical demand on the knee extensors.

Imaging a Central Ionized Component, a Narrow Ring, and the CO Snowline in the Multigapped Disk of HD 169142

Energy Technology Data Exchange (ETDEWEB)

Macías, Enrique; Anglada, Guillem; Osorio, Mayra; Gómez, José F. [Instituto de Astrofísica de Andalucía (CSIC) Glorieta de la Astronomía s/n E-18008 Granada (Spain); Torrelles, José M. [Institut de Ciències de l’Espai (CSIC) and Institut de Ciències del Cosmos (UB)/IEEC, Can Magrans S/N, Cerdanyola del Vallès, Barcelona (Spain); Carrasco-González, Carlos; Rodríguez, Luis F.; Sierra, Anibal, E-mail: emacias@bu.edu [Instituto de Radioastronomía y Astrofísica UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán (Mexico)

2017-04-01

We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the millimeter emission of this disk with the highest angular resolution so far (0.″12 × 0.″09, or 14 au × 11 au, at 7 mm). Our 7 and 9 mm images show a narrow ring of emission at a radius of ∼25 au tracing the outer edge of the inner gap. This ring presents an asymmetric morphology that could be produced by dynamical interactions between the disk and forming planets. Additionally, the azimuthally averaged radial intensity profiles of the 7 and 9 mm images confirm the presence of the previously reported gap at ∼45 au and reveal a new gap at ∼85 au. We analyzed archival DCO{sup +}(3–2) and C{sup 18}O(2–1) ALMA observations, showing that the CO snowline is located very close to this third outer gap. This suggests that growth and accumulation of large dust grains close to the CO snowline could be the mechanism responsible for this proposed outer gap. Finally, a compact source of emission is detected at 7 mm, 9 mm, and 3 cm toward the center of the disk. Its flux density and spectral index indicate that it is dominated by free–free emission from ionized gas, which could be associated with the photoionization of the inner disk, an independent object, or an ionized jet.

Imaging a Central Ionized Component, a Narrow Ring, and the CO Snowline in the Multigapped Disk of HD 169142

International Nuclear Information System (INIS)

Macías, Enrique; Anglada, Guillem; Osorio, Mayra; Gómez, José F.; Torrelles, José M.; Carrasco-González, Carlos; Rodríguez, Luis F.; Sierra, Anibal

2017-01-01

We report Very Large Array observations at 7 mm, 9 mm, and 3 cm toward the pre-transitional disk of the Herbig Ae star HD 169142. These observations have allowed us to study the millimeter emission of this disk with the highest angular resolution so far (0.″12 × 0.″09, or 14 au × 11 au, at 7 mm). Our 7 and 9 mm images show a narrow ring of emission at a radius of ∼25 au tracing the outer edge of the inner gap. This ring presents an asymmetric morphology that could be produced by dynamical interactions between the disk and forming planets. Additionally, the azimuthally averaged radial intensity profiles of the 7 and 9 mm images confirm the presence of the previously reported gap at ∼45 au and reveal a new gap at ∼85 au. We analyzed archival DCO + (3–2) and C 18 O(2–1) ALMA observations, showing that the CO snowline is located very close to this third outer gap. This suggests that growth and accumulation of large dust grains close to the CO snowline could be the mechanism responsible for this proposed outer gap. Finally, a compact source of emission is detected at 7 mm, 9 mm, and 3 cm toward the center of the disk. Its flux density and spectral index indicate that it is dominated by free–free emission from ionized gas, which could be associated with the photoionization of the inner disk, an independent object, or an ionized jet.

Research and development of a superconducting flywheel power storage system in fiscal 1998. Research and development of rotation control technology; 1998 nendo koon chodendo flywheel denryoku chozo kenkyu kaihatsu. Kaiten seigyo no kenkyu kaihatsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

Element technology research was performed on 'rotation control' aimed at practical application of a 10-MW class high-temperature superconducting flywheel power storage system. As part of the research, researches were carried out on small-size and middle-size models, low-loss control type magnetic bearing, and large-size models. For the small-size model, as a result of performing performance tests on the protective bearing by using a testing machine, it was revealed that the model is free of problems in the test for up to 5000 rpm. For the middle-size model, fabrication and installation were completed on a middle-size rotation control testing equipment having CFRP-made flywheel with a diameter of 1 m. In the control type bearing, as a result of adopting a homo-polar type magnetic pole, the rotation loss was reduced to about 1/5 of that of a hetero-polar type. The amount is about 75 W (12000 rpm) when the bias current is 1.5 A. Concept design was implemented on a 2-MWh flywheel bearing system supported with a high-temperature superconducting magnetic bearing as a full-size flywheel. The CFRP-made flywheel has a diameter of 4 m, and a circumferential velocity of 1200 m. (NEDO)

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

Dynamical analysis of a flywheel-superconducting bearing with a moving magnet support

International Nuclear Information System (INIS)

Sivrioglu, Selim; Nonami, Kenzo

2003-01-01

A lateral stiffness improvement approach based on a moving magnet support is developed to reduce the vibration of a flywheel rotor-high temperature superconductor (HTS) bearing. A flywheel rotor levitated with an HTS bearing is modelled and then analysed with a moving stator magnet placed above the rotor. A dynamic support principle is introduced based on moving the stator magnet in anti-phase with the rotor displacement for small variations. A complete dynamical equation of the flywheel rotor is derived including gyroscopic and imbalance effects. The simulation results showed that the dynamic support of the flywheel rotor with additional stator magnet movements decreases the vibration of the flywheel rotor considerably

Modeling collisions in circumstellar debris disks

Science.gov (United States)

Nesvold, Erika

2015-10-01

Observations of resolved debris disks show a spectacular variety of features and asymmetries, including inner cavities and gaps, inclined secondary disks or warps, and eccentric, sharp-edged rings. Embedded exoplanets could create many of these features via gravitational perturbations, which sculpt the disk directly and by generating planetesimal collisions. In this thesis, I present the Superparticle Model/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. I show that SMACK is stable to numerical viscosity and numerical heating over 107 yr, and that it can reproduce analytic models of disk evolution. As an example of the algorithm's capabilities, I use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit and demonstrate that differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring. To demonstrate SMACK's utility in studying debris disk physics, I apply SMACK to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (alpha = 2/7). I find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index alpha of the power law depends on the age of the system t relative to the collisional timescale t coll of the disk by alpha = 0.32(t/ tcoll)-0.04, with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion

Instantaneous flywheel torque of IC engine grey-box identification

Science.gov (United States)

Milašinović, A.; Knežević, D.; Milovanović, Z.; Škundrić, J.

2018-01-01

In this paper a mathematical model developed for the identification of excitation torque acting on the IC engine flywheel is presented. The excitation torque gained through internal combustion of the fuel in the IC engine is transmitted from the flywheel to the transmission. The torque is not constant but variable and is a function of the crank angle. The verification of the mathematical model was done on a 4-cylinder 4-stroke diesel engine for which the in-cylinder pressure was measured in one cylinder and the instantaneous angular speed of the crankshaft at its free end. The research was conducted on a hydraulic engine brake. Inertial forces of all rotational parts, from flywheel to the turbine wheel of the engine brake, are acting on the flywheel due to the nonuniform motion of the flywheel. It is known from the theory of turbomachinery that the torque on the hydraulic brake is a quadratic function of angular speed. Due to that and the variable angular speed of the turbine wheel of the engine brake, the torque during one engine cycle is also variable. The motivation for this research was the idea (intention) to determine the instantaneous torque acting on the flywheel as a function of the crank angle with a mathematical model without any measuring and based on this to determine the quality of work of specific cylinders of the multi-cylinder engine. The crankshaft was considered elastic and also its torsional vibrations were taken into account.

On the Optimally Controlled Hydrostatic Mechanical Drive in Case of Flywheel Acceleration

Directory of Open Access Journals (Sweden)

V. A. Korsunskii

2016-01-01

Full Text Available An improving dynamic quality of vehicles and enhanced fuel efficiency are gained thanks to the combined power system (CPS, comprising a main energy source - internal combustion engine (ICE with an attained level of the power source - and an auxiliary energy source, i.e. an energy storage device (a flywheel.To solve this problem was developed a mathematical model of CPS comprising internal combustion engine and flywheel energy storage (FES with stepless drive.The stepless drive of the flywheel is made to be hydrostatic mechanical to raise the system efficiency. To reduce the drive weight and simplify the control system in the hydraulic part of the flywheel drive is used only one hydraulic unit being controlled.The paper presents a kinematic diagram of the track-type vehicle equipped with the CPS that has a hydrostatic mechanical drive of the flywheel and a mechanical transmission.A mathematical model of the system comprising an ICE, hydrostatic mechanical drive, and FES with stepless drive has been developed. This mathematical model was used to study the influence of ICE and flywheel drive parameters on the dynamic characteristics of the system.The paper estimates the impact of flywheel energy consumption, pressure in the hydraulic system, and control parameter of hydrostatic mechanical drive on the charging time of FES.The obtained piecewise linear law to control the regulation parameter of the hydraulic unit allows us to minimize the charging time of the flywheel at the short-term stops and in the parking area of a tracked vehicle equipped with a CPS.The causes affecting the performance of ‘ICE – drive – flywheel’ system in the course of the flywheel acceleration are a restricted maximum power of the engine, as well as a limited generating capacity, and a maximum flywheel drive hydro-system pressure.The obtained results allow us to determine rational parameters of the flywheel and the laws of drive control to provide their further

An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies

Energy Technology Data Exchange (ETDEWEB)

Gao Hua [Department of Astronomy, School of Physics, Peking University, Beijing 100871 (China); Ho, Luis C. [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

2017-08-20

The development of two-dimensional (2D) bulge-to-disk decomposition techniques has shown their advantages over traditional one-dimensional (1D) techniques, especially for galaxies with non-axisymmetric features. However, the full potential of 2D techniques has yet to be fully exploited. Secondary morphological features in nearby disk galaxies, such as bars, lenses, rings, disk breaks, and spiral arms, are seldom accounted for in 2D image decompositions, even though some image-fitting codes, such as GALFIT, are capable of handling them. We present detailed, 2D multi-model and multi-component decomposition of high-quality R -band images of a representative sample of nearby disk galaxies selected from the Carnegie-Irvine Galaxy Survey, using the latest version of GALFIT. The sample consists of five barred and five unbarred galaxies, spanning Hubble types from S0 to Sc. Traditional 1D decomposition is also presented for comparison. In detailed case studies of the 10 galaxies, we successfully model the secondary morphological features. Through a comparison of best-fit parameters obtained from different input surface brightness models, we identify morphological features that significantly impact bulge measurements. We show that nuclear and inner lenses/rings and disk breaks must be properly taken into account to obtain accurate bulge parameters, whereas outer lenses/rings and spiral arms have a negligible effect. We provide an optimal strategy to measure bulge parameters of typical disk galaxies, as well as prescriptions to estimate realistic uncertainties of them, which will benefit subsequent decomposition of a larger galaxy sample.

An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies

Science.gov (United States)

Gao, Hua; Ho, Luis C.

2017-08-01

The development of two-dimensional (2D) bulge-to-disk decomposition techniques has shown their advantages over traditional one-dimensional (1D) techniques, especially for galaxies with non-axisymmetric features. However, the full potential of 2D techniques has yet to be fully exploited. Secondary morphological features in nearby disk galaxies, such as bars, lenses, rings, disk breaks, and spiral arms, are seldom accounted for in 2D image decompositions, even though some image-fitting codes, such as GALFIT, are capable of handling them. We present detailed, 2D multi-model and multi-component decomposition of high-quality R-band images of a representative sample of nearby disk galaxies selected from the Carnegie-Irvine Galaxy Survey, using the latest version of GALFIT. The sample consists of five barred and five unbarred galaxies, spanning Hubble types from S0 to Sc. Traditional 1D decomposition is also presented for comparison. In detailed case studies of the 10 galaxies, we successfully model the secondary morphological features. Through a comparison of best-fit parameters obtained from different input surface brightness models, we identify morphological features that significantly impact bulge measurements. We show that nuclear and inner lenses/rings and disk breaks must be properly taken into account to obtain accurate bulge parameters, whereas outer lenses/rings and spiral arms have a negligible effect. We provide an optimal strategy to measure bulge parameters of typical disk galaxies, as well as prescriptions to estimate realistic uncertainties of them, which will benefit subsequent decomposition of a larger galaxy sample.

An Optimal Strategy for Accurate Bulge-to-disk Decomposition of Disk Galaxies

International Nuclear Information System (INIS)

Gao Hua; Ho, Luis C.

2017-01-01

The development of two-dimensional (2D) bulge-to-disk decomposition techniques has shown their advantages over traditional one-dimensional (1D) techniques, especially for galaxies with non-axisymmetric features. However, the full potential of 2D techniques has yet to be fully exploited. Secondary morphological features in nearby disk galaxies, such as bars, lenses, rings, disk breaks, and spiral arms, are seldom accounted for in 2D image decompositions, even though some image-fitting codes, such as GALFIT, are capable of handling them. We present detailed, 2D multi-model and multi-component decomposition of high-quality R -band images of a representative sample of nearby disk galaxies selected from the Carnegie-Irvine Galaxy Survey, using the latest version of GALFIT. The sample consists of five barred and five unbarred galaxies, spanning Hubble types from S0 to Sc. Traditional 1D decomposition is also presented for comparison. In detailed case studies of the 10 galaxies, we successfully model the secondary morphological features. Through a comparison of best-fit parameters obtained from different input surface brightness models, we identify morphological features that significantly impact bulge measurements. We show that nuclear and inner lenses/rings and disk breaks must be properly taken into account to obtain accurate bulge parameters, whereas outer lenses/rings and spiral arms have a negligible effect. We provide an optimal strategy to measure bulge parameters of typical disk galaxies, as well as prescriptions to estimate realistic uncertainties of them, which will benefit subsequent decomposition of a larger galaxy sample.

Static Properties of Superconductor Journal Bearing Substator for Superconductor Flywheel Energy Storage System

International Nuclear Information System (INIS)

Park, B. J.; Jung, S. Y.; Lee, J. P.; Park, B. C.; Jeong, N. H.; Sung, T. H.; Han, Y. H.

2008-01-01

A Superconductor Flywheel Energy Storage System(SFES) mainly consists of a pair of non-contacting High Temperature Superconductor(HTS) bearings that provide very low frictional losses, a composite flywheel with high energy storage density. The HTS bearings, which offer dynamic stability without active control, are the key technology that distinguishes the SFES from other flywheel energy storage devices, and great effort is being put into developing this technology. The Superconductor Journal Bearing(SJB) mainly consists of HTS bulks and a stator, which holds the HTS bulks and also acts as a cold head. Static properties of HTS bearings provide data to solve problems which may occur easily in a running system. Since stiffness to counter vibration is the main parameter in designing an HTS bearing system, we investigate SJB magnetic force through static properties between the Permanent Magnet(PM) and HTS. We measure stiffness in static condition and the results are used to determine the optimal number of HTS bulks for a 100kWh SFES.

Performance enhanced design of chaos controller for the mechanical centrifugal flywheel governor system via adaptive dynamic surface control

Directory of Open Access Journals (Sweden)

Shaohua Luo

2016-09-01

Full Text Available This paper addresses chaos suppression of the mechanical centrifugal flywheel governor system with output constraint and fully unknown parameters via adaptive dynamic surface control. To have a certain understanding of chaotic nature of the mechanical centrifugal flywheel governor system and subsequently design its controller, the useful tools like the phase diagrams and corresponding time histories are employed. By using tangent barrier Lyapunov function, a dynamic surface control scheme with neural network and tracking differentiator is developed to transform chaos oscillation into regular motion and the output constraint rule is not broken in whole process. Plugging second-order tracking differentiator into chaos controller tackles the “explosion of complexity” of backstepping and improves the accuracy in contrast with the first-order filter. Meanwhile, Chebyshev neural network with adaptive law whose input only depends on a subset of Chebyshev polynomials is derived to learn the behavior of unknown dynamics. The boundedness of all signals of the closed-loop system is verified in stability analysis. Finally, the results of numerical simulations illustrate effectiveness and exhibit the superior performance of the proposed scheme by comparing with the existing ADSC method.

Grand-design Spiral Arms in a Young Forming Circumstellar Disk

Energy Technology Data Exchange (ETDEWEB)

Tomida, Kengo; Lin, Chia Hui [Department of Earth and Space Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Machida, Masahiro N. [Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University, Nishi-ku, Fukuoka 819-0395 (Japan); Hosokawa, Takashi [Department of Physics, Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan); Sakurai, Yuya, E-mail: tomida@vega.ess.sci.osaka-u.ac.jp [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan)

2017-01-20

We study formation and long-term evolution of a circumstellar disk in a collapsing molecular cloud core using a resistive magnetohydrodynamic simulation. While the formed circumstellar disk is initially small, it grows as accretion continues, and its radius becomes as large as 200 au toward the end of the Class-I phase. A pair of grand-design spiral arms form due to gravitational instability in the disk, and they transfer angular momentum in the highly resistive disk. Although the spiral arms disappear in a few rotations as expected in a classical theory, new spiral arms form recurrently as the disk, soon becoming unstable again by gas accretion. Such recurrent spiral arms persist throughout the Class-0 and I phases. We then perform synthetic observations and compare our model with a recent high-resolution observation of a young stellar object Elias 2–27, whose circumstellar disk has grand-design spiral arms. We find good agreement between our theoretical model and the observation. Our model suggests that the grand-design spiral arms around Elias 2–27 are consistent with material arms formed by gravitational instability. If such spiral arms commonly exist in young circumstellar disks, it implies that young circumstellar disks are considerably massive and gravitational instability is the key process of angular momentum transport.

Grand-design Spiral Arms in a Young Forming Circumstellar Disk

International Nuclear Information System (INIS)

Tomida, Kengo; Lin, Chia Hui; Machida, Masahiro N.; Hosokawa, Takashi; Sakurai, Yuya

2017-01-01

We study formation and long-term evolution of a circumstellar disk in a collapsing molecular cloud core using a resistive magnetohydrodynamic simulation. While the formed circumstellar disk is initially small, it grows as accretion continues, and its radius becomes as large as 200 au toward the end of the Class-I phase. A pair of grand-design spiral arms form due to gravitational instability in the disk, and they transfer angular momentum in the highly resistive disk. Although the spiral arms disappear in a few rotations as expected in a classical theory, new spiral arms form recurrently as the disk, soon becoming unstable again by gas accretion. Such recurrent spiral arms persist throughout the Class-0 and I phases. We then perform synthetic observations and compare our model with a recent high-resolution observation of a young stellar object Elias 2–27, whose circumstellar disk has grand-design spiral arms. We find good agreement between our theoretical model and the observation. Our model suggests that the grand-design spiral arms around Elias 2–27 are consistent with material arms formed by gravitational instability. If such spiral arms commonly exist in young circumstellar disks, it implies that young circumstellar disks are considerably massive and gravitational instability is the key process of angular momentum transport.

Report on the FY 1999 R and D on high temperature superconducting flywheel energy storage. System design/evaluation (Comparative study and information collection); 1999 nendo koon chodendo flywheel denryoku chozo kenkyu kaihatsu. System sekkei hyoka (hikaku kento, joho shushu)

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-05-01

Following the previous fiscal year, a flywheel technology survey committee by men of learning and experience was organized to make a comparative study on various flywheel energy storage systems. Concerning the list-making for checking each element of the high temperature superconducting flywheel system, characteristics and reasons for employment of the small model and medium model were outlined in terms of the system structure (structure in single unit, structure in more than one units), flywheel, bearing, electrically-driven generator, etc. Also about the system in which no superconducting magnetic bearing is used, the information is collected in Japan and abroad through internet, etc., to outline the system. Further, main results obtained in the project were made public in main international conferences or academic meetings such as EUCAS and ISOTC108. At the same time, visits were paid to research institutes such as Cambridge University in the U.K. for the purpose of supplementing the survey so far made, to investigate the recent trend of the research. (NEDO)

FLYWHEEL ENERGY STORAGE SYSTEMS WITH SUPERCONDUCTING BEARINGS FOR UTILITY APPLICATIONS

Energy Technology Data Exchange (ETDEWEB)

Dr. Michael Strasik; Mr. Arthur Day; Mr. Philip Johnson; Dr. John Hull

2007-10-26

This project’s mission was to achieve significant advances in the practical application of bulk high-temperature superconductor (HTS) materials to energy-storage systems. The ultimate product was planned as an operational prototype of a flywheel system on an HTS suspension. While the final prototype flywheel did not complete the final offsite demonstration phase of the program, invaluable lessons learned were captured on the laboratory demonstration units that will lead to the successful deployment of a future HTS-stabilized, composite-flywheel energy-storage system (FESS).

FLYWHEEL ENERGY STORAGE SYSTEMS WITH SUPERCONDUCTING BEARINGS FOR UTILITY APPLICATIONS

International Nuclear Information System (INIS)

Dr. Michael Strasik; Mr. Arthur Day; Mr. Philip Johnson; Dr. John Hull

2007-01-01

This project's mission was to achieve significant advances in the practical application of bulk high-temperature superconductor (HTS) materials to energy-storage systems. The ultimate product was planned as an operational prototype of a flywheel system on an HTS suspension. While the final prototype flywheel did not complete the final offsite demonstration phase of the program, invaluable lessons learned were captured on the laboratory demonstration units that will lead to the successful deployment of a future HTS-stabilized, composite-flywheel energy-storage system (FESS)

THE REDUCTION OF VIBRATIONS IN A CAR – THE PRINCIPLE OF PNEUMATIC DUAL MASS FLYWHEEL

Directory of Open Access Journals (Sweden)

Robert GREGA

2014-09-01

Full Text Available The dual-mass flywheel replaces the classic flywheel in such way that it is divided into two masses (the primary mass and the secondary mass, which are jointed together by means of a flexible interconnection. This kind of the flywheel solution enables to change resonance areas of the engine with regard to the engine dynamic behaviour what leads to a reduction of vibrations consequently. However, there is also a disadvantage of the dualmass flywheels. The disadvantage is its short-time durability. There was projected a new type of the dual-mass flywheel in the framework of our workplace in order to eliminate disadvantages of the present dual-mass flywheels, i.e. we projected the pneumatic dual-mass flywheel, taking into consideration our experiences obtained during investigation of vibrations.

Experimental Evaluation of a High Speed Flywheel for an Energy Cache System

Science.gov (United States)

Haruna, J.; Murai, K.; Itoh, J.; Yamada, N.; Hirano, Y.; Fujimori, T.; Homma, T.

2011-03-01

A flywheel energy cache system (FECS) is a mechanical battery that can charge/discharge electricity by converting it into the kinetic energy of a rotating flywheel, and vice versa. Compared to a chemical battery, a FECS has great advantages in durability and lifetime, especially in hot or cold environments. Design simulations of the FECS were carried out to clarify the effects of the composition and dimensions of the flywheel rotor on the charge/discharge performance. The rotation speed of a flywheel is limited by the strength of the materials from which it is constructed. Three materials, carbon fiber-reinforced polymer (CFRP), Cr-Mo steel, and a Mg alloy were examined with respect to the required weight and rotation speed for a 3 MJ (0.8 kWh) charging/discharging energy, which is suitable for an FECS operating with a 3-5 kW photovoltaic device in an ordinary home connected to a smart grid. The results demonstrate that, for a stationary 3 MJ FECS, Cr-Mo steel was the most cost-effective, but also the heaviest, Mg-alloy had a good balance of rotation speed and weight, which should result in reduced mechanical loss and enhanced durability and lifetime of the system, and CFRP should be used for applications requiring compactness and a higher energy density. Finally, a high-speed prototype FW was analyzed to evaluate its fundamental characteristics both under acceleration and in the steady state.

Experimental Evaluation of a High Speed Flywheel for an Energy Cache System

International Nuclear Information System (INIS)

Haruna, J; Itoh, J; Murai, K; Yamada, N; Hirano, Y; Homma, T; Fujimori, T

2011-01-01

A flywheel energy cache system (FECS) is a mechanical battery that can charge/discharge electricity by converting it into the kinetic energy of a rotating flywheel, and vice versa. Compared to a chemical battery, a FECS has great advantages in durability and lifetime, especially in hot or cold environments. Design simulations of the FECS were carried out to clarify the effects of the composition and dimensions of the flywheel rotor on the charge/discharge performance. The rotation speed of a flywheel is limited by the strength of the materials from which it is constructed. Three materials, carbon fiber-reinforced polymer (CFRP), Cr-Mo steel, and a Mg alloy were examined with respect to the required weight and rotation speed for a 3 MJ (0.8 kWh) charging/discharging energy, which is suitable for an FECS operating with a 3-5 kW photovoltaic device in an ordinary home connected to a smart grid. The results demonstrate that, for a stationary 3 MJ FECS, Cr-Mo steel was the most cost-effective, but also the heaviest, Mg-alloy had a good balance of rotation speed and weight, which should result in reduced mechanical loss and enhanced durability and lifetime of the system, and CFRP should be used for applications requiring compactness and a higher energy density. Finally, a high-speed prototype FW was analyzed to evaluate its fundamental characteristics both under acceleration and in the steady state.

Study of Servo Press with a Flywheel

Science.gov (United States)

Tso, Pei-Lum; Li, Cheng-Ho

The servo press with a flywheel is able to provide flexible motions with energy-saving merit, but its true potential has not been thoroughly studied and verified. In this paper, such the “hybrid-driven” servo press is focused on, and the stamping capacity and the energy distribution between the flywheel and the servomotor are investigated. The capacity is derived based on the principle of energy conservation, and a method of using a capacity percentage plane for evaluation is proposed. A case study is included to illustrate and interpret that the stamping capacity is highly dependent on the programmed punch motions, thus the capacity prediction is always necessary while applying this kind of servo press. The energy distribution is validated by blanking experiments, and the results indicate that the servomotor needs only to provide 15% to the flywheel torque, 12% of the total stamping energy. This validates that the servomotor power is significantly saved in comparison with conventional servo presses.

COMPARATIVE ANALYSIS OF ENERGY ACCUMULATION SYSTEMS AND DETERMINATION OF OPTIMAL APPLICATION AREAS FOR MODERN SUPER FLYWHEELS

Directory of Open Access Journals (Sweden)

M. A. Sokolov

2014-07-01

Full Text Available The paper presents a review and comparative analysis of late years native and foreign literature on various energy storage devices: state of the art designs, application experience in various technical fields. Comparative characteristics of energy storage devices are formulated: efficiency, quality and stability. Typical characteristics are shown for such devices as electrochemical batteries, super capacitors, pumped hydroelectric storage, power systems based on compressed air and superconducting magnetic energy storage systems. The advantages and prospects of high-speed super flywheels as means of energy accumulation in the form of rotational kinetic energy are shown. High output power of a super flywheels energy storage system gives the possibility to use it as a buffer source of peak power. It is shown that super flywheels have great life cycle (over 20 years and are environmental. A distinctive feature of these energy storage devices is their good scalability. It is demonstrated that super flywheels are especially effective in hybrid power systems that operate in a charge/discharge mode, and are used particularly in electric vehicles. The most important factors for space applications of the super flywheels are their modularity, high efficiency, no mechanical friction and long operating time without maintenance. Quick response to network disturbances and high power output can be used to maintain the desired power quality and overall network stability along with fulfilling energy accumulation needs.

Coasting characteristic of the flywheel system under anisotropy effect of bulk high temperature superconductors

Science.gov (United States)

Wu, J. F.; Li, Y.

2014-10-01

High-temperature superconductors (HTSCs) array with aligned growth section boundary (GSB) pattern (AGSBP) exhibits larger levitation force and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP) has been studied in maglev train application (Zheng et al., 2013). This result maybe helpful and support a new way for the HTS bearing design for flywheel systems. So, in this paper, we further examine this growth anisotropy effect on the maglev performance of flywheel system. Levitation force and coasting time were investigated from the point-view of HTS flywheel applications. The GS/GSB alignment of AGSBP bulk HTSCs produces larger levitation force than that of MGSBP, but the coasting time is shorter than that of MGSBP, that is to say, the electric magnetic drag force with AGSBP is larger than that of MGSBP. This result may also exist in the maglev guideline when the maglev train stops freely.

An Evershed type superconducting flywheel bearing

Energy Technology Data Exchange (ETDEWEB)

Cansiz, A.; Campbell, A.M.; Coombs, T.A

2003-07-15

The objective of this work is to develop a bearing using high temperature superconductors (HTSs) for use in an energy storage flywheel. The experimental apparatus includes a cylindrical rotor levitated with the Evershed design in which the majority of the levitation force is provided by a permanent magnet arrangement and the stabilization of the system is achieved by HTS elements. The design characteristics and dynamics of the bearing associated with the rotor part are presented. The instrumentation measures the out of balance force and magnetomechanical stiffness associated with the rotor. A study of the rotational losses was performed using free spin down experiments associated with magnetic field variation measurements. The results are consistent with the loss being caused by hysteresis in the superconductor due to magnet inhomogeneity.

Coasting characteristic of the flywheel system under anisotropy effect of bulk high temperature superconductors

International Nuclear Information System (INIS)

Wu, J.F.; Li, Y.

2014-01-01

Highlights: • Coasting time was investigated from the point-view of HTS flywheel applications. • The coasting time of aligned growth section boundary pattern (AGSBP) is shorter than that of MGSBP. • The electric magnetic drag force with AGSBP is larger than that of MGSBP. • This result may also exist in the maglev guideline when the maglev train stops freely. - Abstract: High-temperature superconductors (HTSCs) array with aligned growth section boundary (GSB) pattern (AGSBP) exhibits larger levitation force and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP) has been studied in maglev train application (Zheng et al., 2013). This result maybe helpful and support a new way for the HTS bearing design for flywheel systems. So, in this paper, we further examine this growth anisotropy effect on the maglev performance of flywheel system. Levitation force and coasting time were investigated from the point-view of HTS flywheel applications. The GS/GSB alignment of AGSBP bulk HTSCs produces larger levitation force than that of MGSBP, but the coasting time is shorter than that of MGSBP, that is to say, the electric magnetic drag force with AGSBP is larger than that of MGSBP. This result may also exist in the maglev guideline when the maglev train stops freely

Coasting characteristic of the flywheel system under anisotropy effect of bulk high temperature superconductors

Energy Technology Data Exchange (ETDEWEB)

Wu, J.F., E-mail: wujf@ciomp.ac.cn; Li, Y.

2014-10-15

Highlights: • Coasting time was investigated from the point-view of HTS flywheel applications. • The coasting time of aligned growth section boundary pattern (AGSBP) is shorter than that of MGSBP. • The electric magnetic drag force with AGSBP is larger than that of MGSBP. • This result may also exist in the maglev guideline when the maglev train stops freely. - Abstract: High-temperature superconductors (HTSCs) array with aligned growth section boundary (GSB) pattern (AGSBP) exhibits larger levitation force and suppression of levitation force decay above a permanent magnet guideway (PMG) compared with misaligned GSB pattern (MGSBP) has been studied in maglev train application (Zheng et al., 2013). This result maybe helpful and support a new way for the HTS bearing design for flywheel systems. So, in this paper, we further examine this growth anisotropy effect on the maglev performance of flywheel system. Levitation force and coasting time were investigated from the point-view of HTS flywheel applications. The GS/GSB alignment of AGSBP bulk HTSCs produces larger levitation force than that of MGSBP, but the coasting time is shorter than that of MGSBP, that is to say, the electric magnetic drag force with AGSBP is larger than that of MGSBP. This result may also exist in the maglev guideline when the maglev train stops freely.

Design and Optimization Method of a Two-Disk Rotor System

Science.gov (United States)

Huang, Jingjing; Zheng, Longxi; Mei, Qing

2016-04-01

An integrated analytical method based on multidisciplinary optimization software Isight and general finite element software ANSYS was proposed in this paper. Firstly, a two-disk rotor system was established and the mode, humorous response and transient response at acceleration condition were analyzed with ANSYS. The dynamic characteristics of the two-disk rotor system were achieved. On this basis, the two-disk rotor model was integrated to the multidisciplinary design optimization software Isight. According to the design of experiment (DOE) and the dynamic characteristics, the optimization variables, optimization objectives and constraints were confirmed. After that, the multi-objective design optimization of the transient process was carried out with three different global optimization algorithms including Evolutionary Optimization Algorithm, Multi-Island Genetic Algorithm and Pointer Automatic Optimizer. The optimum position of the two-disk rotor system was obtained at the specified constraints. Meanwhile, the accuracy and calculation numbers of different optimization algorithms were compared. The optimization results indicated that the rotor vibration reached the minimum value and the design efficiency and quality were improved by the multidisciplinary design optimization in the case of meeting the design requirements, which provided the reference to improve the design efficiency and reliability of the aero-engine rotor.

Comparison of central axis and jet ring coolant supply for turbine disk cooling on a SSME-HPOTP model

Science.gov (United States)

Kim, Y. W.; Metzger, D. E.

1992-01-01

The test facility, test methods and results are presented for an experimental study modeling the cooling of turbine disks in the blade attachment regions with multiple impinging jets, in a configuration simulating the disk cooling method employed on the Space Shuttle Main Engine oxygen turbopump. The study's objective was to provide a comparison of detailed local convection heat transfer rates obtained for a single center-supply of disk coolant with those obtained with the present flight configuration where disk coolant is supplied through an array of 19 jets located near the disk outer radius. Specially constructed disk models were used in a program designed to evaluate possible benefits and identify any possible detrimental effects involved in employing an alternate disk cooling scheme. The study involved the design, construction and testing of two full scale rotating model disks, one plane and smooth for baseline testing and the second contoured to the present flight configuration, together with the corresponding plane and contoured stator disks. Local heat transfer rates are determined from the color display of encapsulated liquid crystals coated on the disk in conjunction with use of a computer vision system. The test program was composed of a wide variety of disk speeds, flowrates, and geometrical configurations, including testing for the effects of disk boltheads and gas ingestion from the gas path region radially outboard of the disk-cavity.

Sulfite induced autoxidation of Cu(II/tetra/ penta and hexaglycine complexes: spectrophotometric and rotating-ring-disk glassy carbon electrode studies and analytical potentialities

Directory of Open Access Journals (Sweden)

Alipázaga Maria V.

2003-01-01

Full Text Available The oxidation of Cu(II complexes with tetra, penta and hexaglycine in borate buffer aqueous solution, by dissolved oxygen is strongly accelerated by sulfite. The formation of Cu(III complexes with maximum absorbances at 250 nm (e = 9000 mol-1 L cm-1 and 365 nm (e = 7120 mol-1 L cm-1 was also characterized by using rotating ring-disk voltammetry, whose anodic and cathodic components were observed in voltammograms recorded in solutions containing Cu(II. Voltammograms, obtained at various rotation speeds, showed that the Cu(III species electrochemically generated is not stable over the entire time window of the experiment and in solutions containing tetraglycine the overall limiting current is controlled by the kinetics of an equilibrium involving Cu(II species.The calculated first order rate constant of the decomposition was 4.37x10-3 s-1. Electrochemical experiments carried out in Cu(II solutions after the addition of relatively small amounts of sulfite demonstrated that the Cu(III species formed in the chemical reaction is the same as the one collected at the ring electrode when Cu(II is oxidized at the disk electrode in ring-disk voltammetry. The concentration of Cu(III complexes is proportional to the amount of added sulfite and the results indicated that indirect analytical methods for sulfite may be developed by means of spectrophotometric or amperometric detection of the chemically generated product.

Built and operation of three powerful AC pulse flywheel generator sets

International Nuclear Information System (INIS)

Wang Shujin; Li Huajun; Li Zhijian; Huang Zhaorong; Wang Xiaoping; Xu Lirong; Liu Xuemei; Bu Mingnan; Hu Haotian; Mao Weicheng

2006-10-01

Based on modification of the old pulse generator sets the new flywheel generator system has been developed. Now it is successfully used in supplying power to the HL-2A tokamak and meets the needs of HL-2A physical experiments. By far it is the most powerful pulse flywheel generator system on in-stalled gross capacity, energy storage and release in China today. In addition, the characteristic of the flywheel generator system is that each generator stator has two Y windings with 30 degree phase shift to avoid damaging the rotor due to rectifying load. (authors)

Damping ring designs and issues

International Nuclear Information System (INIS)

Wolski, Andrzej; Decking, Winfried

2003-01-01

The luminosity performance of a future linear collider (LC) will depend critically on the performance of the damping rings. The design luminosities of the current LC proposals require rings with very short damping times, large acceptance, low equilibrium emittance and high beam intensity. We discuss the design strategies for lattices achieving the goals of dynamical stability, examine the challenges for alignment and coupling correction, and consider a variety of collective effects that threaten to limit beam quality. We put the design goals in context by referring to the experience of operating facilities, and outline the further research and development that is needed

Design of Hierarchical Ring Networks Using Branch-and-Price

DEFF Research Database (Denmark)

Thomadsen, Tommy; Stidsen, Thomas K.

2004-01-01

-ring is designed connecting the metro-rings, minimizing fixed link establishment costs of the federal-ring. A branch-and-price algorithm is presented for the design of the bottom layer and it is suggested that existing methods are used for the design of the federal-ring. Computational results are given...

Superconducting bearings for flywheel applications

DEFF Research Database (Denmark)

Abrahamsen, A.B.

2001-01-01

A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

Structural integrity analysis of reactor coolant pump flywheel(I)

International Nuclear Information System (INIS)

Kim, Young Jin

1986-01-01

A reactor coolant pump flywheel is an important machine element to provide the necessary rotational inertia in the event of loss of power to the pumps. This paper attempts to assess the influence of keyways on flywheel stresses and fracture behaviour in detail. The finite element method was used to determine stresses near keyways, including residual stresses, and to establish stress intensity factors for keyway cracks for use in fracture mechanics assessments. (Author)

Electricity generating system. [Wind/diesel/flywheel system

Energy Technology Data Exchange (ETDEWEB)

Moody, R.L.

1992-02-05

An electricity generating system is described which includes a water tank with electric heating elements connected to the water cooling system of a diesel engine which is heated by excess output of the system. Power in excess of that required by a load which is generated by a wind turbine driven generator runs up a flywheel and further excess is absorbed in the tank. A fan associated with a radiator connected to the tank may be operated to dissipate further excess power. When the load requirements exceed the output of the generators linked to the wind turbine and the flywheel the engine operates a synchronous alternator. (author).

Investigating dust trapping in transition disks with millimeter-wave polarization

Science.gov (United States)

Pohl, A.; Kataoka, A.; Pinilla, P.; Dullemond, C. P.; Henning, Th.; Birnstiel, T.

2016-08-01

Context. Spatially resolved polarized (sub-)mm emission has been observed for example in the protoplanetary disk around HL Tau. Magnetically aligned grains are commonly interpreted as the source of polarization. However, self-scattering by large dust grains with a high enough albedo is another polarization mechanism, which is becoming a compelling method independent of the spectral index to constrain the dust grain size in protoplanetary disks. Aims: We study the dust polarization at mm wavelengths in the dust trapping scenario proposed for transition disks, when a giant planet opens a gap in the disk. We investigate the characteristic polarization patterns and their dependence on disk inclination, dust size evolution, planet position, and observing wavelength. Methods: We combine two-dimensional hydrodynamical simulations of planet-disk interactions with self-consistent dust growth models. These size-dependent dust density distributions are used for follow-up three-dimensional radiative transfer calculations to predict the polarization degree at ALMA bands due to scattered thermal emission. Results: Dust self-scattering has been proven to be a viable mechanism for producing polarized mm-wave radiation. We find that the polarization pattern of a disk with a planetary gap after 1 Myr of dust evolution shows a distinctive three-ring structure. Two narrow inner rings are located at the planet gap edges. A third wider ring of polarization is situated in the outer disk beyond 100 au. For increasing observing wavelengths, all three rings change their position slightly, where the innermost and outermost rings move inward. This distance is detectable when comparing the results at ALMA bands 3, 6, and 7. Within the highest polarized intensity regions the polarization vectors are oriented in the azimuthal direction. For an inclined disk there is an interplay between polarization originating from a flux gradient and inclination-induced quadrupole polarization. For

GyroVR: Simulating Inertia in Virtual Reality using Head Worn Flywheels

DEFF Research Database (Denmark)

Gugenheimer, Jan; Wolf, Dennis; Eiríksson, Eyþór Rúnar

2016-01-01

We present GyroVR, head worn flywheels designed to render inertia in Virtual Reality (VR. Motions such as flying, diving or floating in outer space generate kinesthetic forces onto our body which impede movement and are currently not represented in VR. We simulate those kinesthetic forces...... by attaching flywheels to the users head, leveraging the gyroscopic effect of resistance when changing the spinning axis of rotation. GyroVR is an ungrounded, wireless and self contained device allowing the user to freely move inside the virtual environment. The generic shape allows to attach it to different...... positions on the users body. We evaluated the impact of GyroVR onto different mounting positions on the head (back and front) in terms of immersion, enjoyment and simulator sickness. Our results show, that attaching GyroVR onto the users head (front of the Head Mounted Display (HMD)) resulted in the highest...

Design studies for the electron storage ring EUTERPE

Energy Technology Data Exchange (ETDEWEB)

Boling, Xi

1995-05-18

The 400 MeV electron storage ring EUTERPE is under construction at Eindhoven University of Technology. The ring is to be used as an experimental tool for accelerator physics studies and synchroton radiation applications. The main task of the current research work is the electron optical design of the ring. Lattice design is a basis for machine design as a whole. Design aspects regarding the basic lattice, based on single particle dynamics, include determination of the equilibrium beam size and bunch length, design of achromatic bending sections, selection of tune values, correction of chromaticity, and minimization of the natural emittance in the ring. The basic lattice designed for the EUTERPE ring has a high flexibility so that different electron optical modes can be realized easily. In low energy storage rings with a high beam current, collective effects can cause a significant change in the bunch length, the transverse emittance and the beam lifetime. In order to ensure a good optical performance for the ring, the choice of suitable parameters concerning the vacuum and RF system are essential as far as collective effects are concerned. An estimation of the collective effects in the ring is given. The injector for EUTERPE is a 75 MeV racetrack microtron which is injected from a 10 MeV linac. In order to get sufficient beam current in the ring, a special procedure of continuous injection with an adjustable locally shifted closed orbit has been presented. Details of the injection procedure and numerical simulations are given. (orig./HSI).

Design studies for the electron storage ring EUTERPE

International Nuclear Information System (INIS)

Xi Boling.

1995-01-01

The 400 MeV electron storage ring EUTERPE is under construction at Eindhoven University of Technology. The ring is to be used as an experimental tool for accelerator physics studies and synchroton radiation applications. The main task of the current research work is the electron optical design of the ring. Lattice design is a basis for machine design as a whole. Design aspects regarding the basic lattice, based on single particle dynamics, include determination of the equilibrium beam size and bunch length, design of achromatic bending sections, selection of tune values, correction of chromaticity, and minimization of the natural emittance in the ring. The basic lattice designed for the EUTERPE ring has a high flexibility so that different electron optical modes can be realized easily. In low energy storage rings with a high beam current, collective effects can cause a significant change in the bunch length, the transverse emittance and the beam lifetime. In order to ensure a good optical performance for the ring, the choice of suitable parameters concerning the vacuum and RF system are essential as far as collective effects are concerned. An estimation of the collective effects in the ring is given. The injector for EUTERPE is a 75 MeV racetrack microtron which is injected from a 10 MeV linac. In order to get sufficient beam current in the ring, a special procedure of continuous injection with an adjustable locally shifted closed orbit has been presented. Details of the injection procedure and numerical simulations are given. (orig./HSI)

Inverter Output Filter Effect on PWM Motor Drives of a Flywheel Energy Storage System

Science.gov (United States)

Santiago, Walter

2004-01-01

NASA Glenn Research Center (GRC) has been involved in the research and development of high speed flywheel systems for small satellite energy storage and attitude control applications. One research and development area has been the minimization of the switching noise produced by the pulsed width modulated (PWM) inverter that drives the flywheel permanent magnet motor/generator (PM M/G). This noise can interfere with the flywheel M/G hardware and the system avionics hampering the full speed performance of the flywheel system. One way to attenuate the inverter switching noise is by placing an AC filter at the three phase output terminals of the inverter with the filter neutral point connected to the DC link (DC bus) midpoint capacitors. The main benefit of using an AC filter in this fashion is the significant reduction of the inverter s high dv/dt switching and its harmonics components. Additionally, common mode (CM) and differential mode (DM) voltages caused by the inverter s high dv/dt switching are also reduced. Several topologies of AC filters have been implemented and compared. One AC filter topology consists of a two-stage R-L-C low pass filter. The other topology consists of the same two-stage R-L-C low pass filter with a series connected trap filter (an inductor and capacitor connected in parallel). This paper presents the analysis, design and experimental results of these AC filter topologies and the comparison between the no filter case and conventional AC filter.

Dynamics of a Flywheel Energy Storage System Supporting a Wind Turbine Generator in a Microgrid

Science.gov (United States)

Nair S, Gayathri; Senroy, Nilanjan

2016-02-01

Integration of an induction machine based flywheel energy storage system with a wind energy conversion system is implemented in this paper. The nonlinear and linearized models of the flywheel are studied, compared and a reduced order model of the same simulated to analyze the influence of the flywheel inertia and control in system response during a wind power change. A quantification of the relation between the inertia of the flywheel and the controller gain is obtained which allows the system to be considered as a reduced order model that is more controllable in nature. A microgrid setup comprising of the flywheel energy storage system, a two mass model of a DFIG based wind turbine generator and a reduced order model of a diesel generator is utilized to analyse the microgrid dynamics accurately in the event of frequency variations arising due to wind power change. The response of the microgrid with and without the flywheel is studied.

Effect of cathode porosity on the Lithium-air cell oxygen reduction reaction – A rotating ring-disk electrode investigation

International Nuclear Information System (INIS)

Seo, Jeongwook; Sankarasubramanian, Shrihari; Singh, Nikhilendra; Mizuno, Fuminori; Takechi, Kensuke; Prakash, Jai

2017-01-01

The kinetics of the oxygen reduction reaction (ORR) on the practical air cathode in a Lithium-air cell, which is conventionally composed of porous carbon with or without catalysts supported on it, was investigated. The mechanism and kinetics of the oxygen reduction reaction (ORR) was studied on a porous carbon electrode in an oxygen saturated solution of 0.1 M Lithium bis-trifluoromethanesulfonimide (LiTFSI) in Dimethoxyethane (DME) using cyclic voltammetery (CV) and the rotating ring-disk electrode (RRDE) technique. The oxygen reduction and evolution reactions were found to occur at similar potentials to those observed on a smooth, planar glassy carbon (GC) electrode. The effect of porosity and the resultant increase in surface area were readily observed in the increase in the transient time required for the intermediates to reach the ring and the much larger disk currents (compared to smooth, planar GC) recorded respectively. The RRDE data was analyzed using a kinetic model previously developed by us and the rate constants for the elementary reactions were calculated. The rates constant for the electrochemical reactions were found to be similar in magnitude to the rate constants calculated for smooth GC disks. The porosity of the electrode was found to decrease the rate of desorption of the intermediate and the product and delay their diffusion by shifting it from a Fickian regime in the electrolyte bulk to the Knudsen regime in the film pores. Thus, it is shown that the effect of the electrode porosity on the kinetics of the ORR is physical rather than electrochemical.

A Review of Flywheel Energy Storage System Technologies and Their Applications

Directory of Open Access Journals (Sweden)

Mustafa E. Amiryar

2017-03-01

Full Text Available Energy storage systems (ESS provide a means for improving the efficiency of electrical systems when there are imbalances between supply and demand. Additionally, they are a key element for improving the stability and quality of electrical networks. They add flexibility into the electrical system by mitigating the supply intermittency, recently made worse by an increased penetration of renewable generation. One energy storage technology now arousing great interest is the flywheel energy storage systems (FESS, since this technology can offer many advantages as an energy storage solution over the alternatives. Flywheels have attributes of a high cycle life, long operational life, high round-trip efficiency, high power density, low environmental impact, and can store megajoule (MJ levels of energy with no upper limit when configured in banks. This paper presents a critical review of FESS in regards to its main components and applications, an approach not captured in earlier reviews. Additionally, earlier reviews do not include the most recent literature in this fast-moving field. A description of the flywheel structure and its main components is provided, and different types of electric machines, power electronics converter topologies, and bearing systems for use in flywheel storage systems are discussed. The main applications of FESS are explained and commercially available flywheel prototypes for each application are described. The paper concludes with recommendations for future research.

Sub-Area. 2.5 Demonstration of Promising Energy Storage Technologies Project Type. Flywheel Energy Storage Demonstration Revision: V1.0

Energy Technology Data Exchange (ETDEWEB)

None, None

2015-12-30

In this program, Amber Kinetics designed, built, and tested a sub-­scale 5 kWh engineering prototype flywheel system. Applying lessons learned from the engineering prototype, Amber Kinetics then designed, built and tested full-­size, commercial-­scale 25 kWh flywheel systems. The systems underwent basic functional qualification testing before being installed, sequentially, at the company’s outdoor test site in Alameda, CA for full-­speed field-testing. The primary considerations in testing the prototype units were to demonstrate the functionality of the system, verify the frequencies of resonant modes, and quantify spinning losses and motor/generator efficiency.

Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites.

Science.gov (United States)

Nedim Ay, Ahmet; Konuk, Deniz; Zümreoglu-Karan, Birgul

2011-02-03

A new nanocomposite architecture is reported which combines prolate spheroidal hematite nanoparticles with drug-carrying layered double hydroxide [LDH] disks in a single structure. Spindle-shaped hematite nanoparticles with average length of 225 nm and width of 75 nm were obtained by thermal decomposition of hydrothermally synthesized hematite. The particles were first coated with Mg-Al-NO3-LDH shell and then subjected to anion exchange with salicylate ions. The resulting bio-nanohybrid displayed a close structural resemblance to that of the Ring Nebula. Scanning electron microscope and transmission electron microscopy images showed that the LDH disks are stacked around the equatorial part of the ellipsoid extending along the main axis. This geometry possesses great structural tunability as the composition of the LDH and the nature of the interlayer region can be tailored and lead to novel applications in areas ranging from functional materials to medicine by encapsulating various guest molecules.

Lattice design for the CEPC double ring scheme

Science.gov (United States)

Wang, Yiwei; Su, Feng; Bai, Sha; Zhang, Yuan; Bian, Tianjian; Wang, Dou; Yu, Chenghui; Gao, Jie

2018-01-01

A future Circular Electron Positron Collider (CEPC) has been proposed by China with the main goal of studying the Higgs boson. Its baseline design, chosen on the basis of its performance, is a double ring scheme; an alternative design is a partial double ring scheme which reduces the budget while maintaining an adequate performance. This paper will present the collider ring lattice design for the double ring scheme. The CEPC will also work as a W and a Z factory. For the W and Z modes, except in the RF region, compatible lattices were obtained by scaling down the magnet strength with energy.

Clean energy storage technology in the making: An innovation systems perspective on flywheel energy storage.

Science.gov (United States)

Wicki, Samuel; Hansen, Erik G

2017-09-20

The emergence and diffusion of green and sustainable technologies is full of obstacles and has therefore become an important area of research. We are interested in further understanding the dynamics between entrepreneurial experimentation, market formation, and institutional contexts, together playing a decisive role for successful diffusion of such technologies. Accordingly, we study these processes by adopting a technological innovation system perspective focusing on actors, networks, and institutions as well as the functions provided by them. Using a qualitative case study research design, we focus on the high-speed flywheel energy storage technology. As flywheels are based on a rotating mass allowing short-term storage of energy in kinetic form, they represent an environmentally-friendly alternative to electrochemical batteries and therefore can play an important role in sustainable energy transitions. Our contribution is threefold: First , regarding the flywheel energy storage technology, our findings reveal two subsystems and related markets in which development took different courses. In the automotive sector, flywheels are developing well as a braking energy recovery technology under the influence of two motors of innovation. In the electricity sector, they are stagnating at the stage of demonstration projects because of two important system weaknesses that counteract demand for storage. Second , we contribute to the theory of technological innovation systems by better understanding the internal dynamics between different functions of an innovation system as well as between the innovation system and its (external) contextual structures. Our third contribution is methodological. According to our best knowledge, we are the first to use system dynamics to (qualitatively) analyze and visualize dynamics between the diverse functions of innovation systems with the aim of enabling a better understanding of complex and iterative system processes. The paper also

Flywheel Challenge: HTS Magnetic Bearing

International Nuclear Information System (INIS)

Werfel, F N; Floegel-Delor, U; Riedel, T; Rothfeld, R; Wippich, D; Goebel, B

2006-01-01

A 200 mm cylindrical engineering prototype high temperature superconducting (HTS) was designed and fabricated. Measurements show that the 17 kg PM rotor can suspend safely 1000 kg in axial direction and 470 kg radially. The rationale for the bearing performance is to stabilize a 400 kg rotor of a new compact 5 kWh/280 kW flywheel energy storage system (COM - FESS). Measurements of the magnetic bearing force, stiffness and drag-torque are presented indicated the successful targeting a milestone in the HTS bearing technology. The influence of the PM configuration and the YBCO temperature on the bearing performance was experimentally studied, providing high-force or high-stiffness behaviour. The axial stiffness 5 kN/mm at 0.5 mm displacement is the highest value of a HTS bearing we know

Performance characteristics of solar-photovoltaic flywheel-storage systems

Science.gov (United States)

Jarvinen, P. O.; Brench, B. L.; Rasmussen, N. E.

A solar photovoltaic energy flywheel storage and conversion system for residential applications was tested. Performance and efficiency measurements were conducted on the system, which utilizes low loss magnetic bearings, maximum power point tracking of the photovoltaic array, integrated permanent magnet motor generator, and output power conditioning sections of either the stand alone cycloconverter or utility interactive inverter type. The overall in/out electrical storage efficiency of the flywheel system was measured along with the power transfer efficiencies of the individual components and the system spin down tare losses. The system compares favorably with systems which use batteries and inverters.

Report of fiscal 1997 R and D result on high temperature superconducting flywheel power storage. System design and evaluation (comparative study and information gathering); 1997 nendo koon chodendo flywheel denryoku chozo kenkyu kaihatsu seika hokokusho. System sekkei hyoka (hikaku kento, joho shushu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

Information gathering and comparative study were conducted for the purpose of putting to practical use a 10 MWh class high temperature superconducting flywheel power storage system. This paper explains the fiscal 1977 results. On various methods conceivable as a flywheel system, characteristics were extracted in such points as structure, shape, axial support system, generator motor, and protective system, and compared with the method being developed in the present project. Test items methods, etc., were studied for a small model system (0.5 kWh, {phi} 400 mm, 30,000 rpm) for the purpose of clarifying problems and ways in approaching a large system (10 MWh class) through various tests of the small one. The main test items were a free-run test, steady state rotation test and a heat-run test, and the main points to evaluate were oscillation characteristics and the control performance of AMB, flux creep and loss, for example. Investigation was conducted of a dummy flywheel experimental equipment and a highly efficient power converter with the object of contributing to the development of a flywheel equipment for daily load leveling. The research members visited seven major research organizations in Europe and gathered information. (NEDO)

Thirty year operational experience of the JET flywheel generators

Energy Technology Data Exchange (ETDEWEB)

Rendell, Daniel, E-mail: dan.rendell@ccfe.ac.uk; Shaw, Stephen R.; Pool, Peter J.; Oberlin-Harris, Colin

2015-10-15

Highlights: • The pony-motor rotor circuit's liquid resistor requires frequent maintenance. • A crowned profile on the thrust pads is desirable. • Both plug braking transformers have been replaced after flashovers occurred. • Two-plane balancing of one of the flywheel generators has improved vibration levels but also provided information to lead further investigations. • A half-life inspection on the flywheel generators has shown no major issues after 30 year of operating. - Abstract: The JET flywheel generator converters have operated since 1983 and for over 85,000 pulses. Problems with this plant are discussed, including corrosion, unbalanced flow and arcing within the liquid resistors; starting difficulties on both machines; and failure of the plug-braking transformers at energisiation. In 2012/13 two sets of thrust bearing pads have required refurbishment, a process which highlighted the importance of their profile. Extensive half-life inspections have shown that there are no serious problems with either generator.

MODELING DUST EMISSION OF HL TAU DISK BASED ON PLANET–DISK INTERACTIONS

International Nuclear Information System (INIS)

Jin, Sheng; Ji, Jianghui; Li, Shengtai; Li, Hui; Isella, Andrea

2016-01-01

We use extensive global two-dimensional hydrodynamic disk gas+dust simulations with embedded planets, coupled with three-dimensional radiative transfer calculations, to model the dust ring and gap structures in the HL Tau protoplanetary disk observed with the Atacama Large Millimeter/Submillimeter Array (ALMA). We include the self-gravity of disk gas and dust components and make reasonable choices of disk parameters, assuming an already settled dust distribution and no planet migration. We can obtain quite adequate fits to the observed dust emission using three planets with masses of 0.35, 0.17, and 0.26 M Jup at 13.1, 33.0, and 68.6 AU, respectively. Implications for the planet formation as well as the limitations of this scenario are discussed

FLYWHEEL BASED KINETIC ENERGY RECOVERY SYSTEMS (KERS) INTEGRATED IN VEHICLES

OpenAIRE

THOMAS MATHEWS; NISHANTH D

2013-01-01

Today, many hybrid electric vehicles have been developed in order to reduce the consumption of fossil fuels; unfortunately these vehicles require electrochemical batteries to store energy, with high costs as well as poor conversion efficiencies. By integrating flywheel hybrid systems, these drawbacks can be overcome and can potentially replace battery powered hybrid vehicles cost effectively. The paper will explain the engineering, mechanics of the flywheel system and it’s working in detail. ...

Predictions for shepherding planets in scattered light images of debris disks

International Nuclear Information System (INIS)

Rodigas, Timothy J.; Hinz, Philip M.; Malhotra, Renu

2014-01-01

Planets can affect debris disk structure by creating gaps, sharp edges, warps, and other potentially observable signatures. However, there is currently no simple way for observers to deduce a disk-shepherding planet's properties from the observed features of the disk. Here we present a single equation that relates a shepherding planet's maximum mass to the debris ring's observed width in scattered light, along with a procedure to estimate the planet's eccentricity and minimum semimajor axis. We accomplish this by performing dynamical N-body simulations of model systems containing a star, a single planet, and an exterior disk of parent bodies and dust grains to determine the resulting debris disk properties over a wide range of input parameters. We find that the relationship between planet mass and debris disk width is linear, with increasing planet mass producing broader debris rings. We apply our methods to five imaged debris rings to constrain the putative planet masses and orbits in each system. Observers can use our empirically derived equation as a guide for future direct imaging searches for planets in debris disk systems. In the fortuitous case of an imaged planet orbiting interior to an imaged disk, the planet's maximum mass can be estimated independent of atmospheric models.

Prolate spheroidal hematite particles equatorially belt with drug-carrying layered double hydroxide disks: Ring Nebula-like nanocomposites

Directory of Open Access Journals (Sweden)

Nedim Ay Ahmet

2011-01-01

Full Text Available Abstract A new nanocomposite architecture is reported which combines prolate spheroidal hematite nanoparticles with drug-carrying layered double hydroxide [LDH] disks in a single structure. Spindle-shaped hematite nanoparticles with average length of 225 nm and width of 75 nm were obtained by thermal decomposition of hydrothermally synthesized hematite. The particles were first coated with Mg-Al-NO3-LDH shell and then subjected to anion exchange with salicylate ions. The resulting bio-nanohybrid displayed a close structural resemblance to that of the Ring Nebula. Scanning electron microscope and transmission electron microscopy images showed that the LDH disks are stacked around the equatorial part of the ellipsoid extending along the main axis. This geometry possesses great structural tunability as the composition of the LDH and the nature of the interlayer region can be tailored and lead to novel applications in areas ranging from functional materials to medicine by encapsulating various guest molecules.

THE VLA VIEW OF THE HL TAU DISK: DISK MASS, GRAIN EVOLUTION, AND EARLY PLANET FORMATION

Energy Technology Data Exchange (ETDEWEB)

Carrasco-González, Carlos; Rodríguez, Luis F.; Galván-Madrid, Roberto [Instituto de Radioastronomía y Astrofísica UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán, México (Mexico); Henning, Thomas; Linz, Hendrik; Birnstiel, Til; Boekel, Roy van; Klahr, Hubert [Max-Planck-Institut für Astronomie Heidelberg, Königstuhl 17, D-69117 Heidelberg (Germany); Chandler, Claire J.; Pérez, Laura [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801-0387 (United States); Anglada, Guillem; Macias, Enrique; Osorio, Mayra [Instituto de Astrofísica de Andalucía (CSIC), Apartado 3004, E-18080 Granada (Spain); Flock, Mario [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Menten, Karl [Jansky Fellow of the National Radio Astronomy Observatory (United States); Testi, Leonardo [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching bei München (Germany); Torrelles, José M. [Institut de Ciències de l’Espai (CSIC-IEEC) and Institut de Ciències del Cosmos (UB-IEEC), Martí i Franquès 1, E-08028 Barcelona (Spain); Zhu, Zhaohuan, E-mail: c.carrasco@crya.unam.mx, E-mail: l.rodriguez@crya.unam.mx, E-mail: r.galvan@crya.unam.mx, E-mail: henning@mpia.de, E-mail: linz@mpia.de [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)

2016-04-10

The first long-baseline ALMA campaign resolved the disk around the young star HL Tau into a number of axisymmetric bright and dark rings. Despite the very young age of HL Tau, these structures have been interpreted as signatures for the presence of (proto)planets. The ALMA images triggered numerous theoretical studies based on disk–planet interactions, magnetically driven disk structures, and grain evolution. Of special interest are the inner parts of disks, where terrestrial planets are expected to form. However, the emission from these regions in HL Tau turned out to be optically thick at all ALMA wavelengths, preventing the derivation of surface density profiles and grain-size distributions. Here, we present the most sensitive images of HL Tau obtained to date with the Karl G. Jansky Very Large Array at 7.0 mm wavelength with a spatial resolution comparable to the ALMA images. At this long wavelength, the dust emission from HL Tau is optically thin, allowing a comprehensive study of the inner disk. We obtain a total disk dust mass of (1–3) × 10{sup −3} M {sub ⊙}, depending on the assumed opacity and disk temperature. Our optically thin data also indicate fast grain growth, fragmentation, and formation of dense clumps in the inner densest parts of the disk. Our results suggest that the HL Tau disk may be actually in a very early stage of planetary formation, with planets not already formed in the gaps but in the process of future formation in the bright rings.

THE VLA VIEW OF THE HL TAU DISK: DISK MASS, GRAIN EVOLUTION, AND EARLY PLANET FORMATION

International Nuclear Information System (INIS)

Carrasco-González, Carlos; Rodríguez, Luis F.; Galván-Madrid, Roberto; Henning, Thomas; Linz, Hendrik; Birnstiel, Til; Boekel, Roy van; Klahr, Hubert; Chandler, Claire J.; Pérez, Laura; Anglada, Guillem; Macias, Enrique; Osorio, Mayra; Flock, Mario; Menten, Karl; Testi, Leonardo; Torrelles, José M.; Zhu, Zhaohuan

2016-01-01

The first long-baseline ALMA campaign resolved the disk around the young star HL Tau into a number of axisymmetric bright and dark rings. Despite the very young age of HL Tau, these structures have been interpreted as signatures for the presence of (proto)planets. The ALMA images triggered numerous theoretical studies based on disk–planet interactions, magnetically driven disk structures, and grain evolution. Of special interest are the inner parts of disks, where terrestrial planets are expected to form. However, the emission from these regions in HL Tau turned out to be optically thick at all ALMA wavelengths, preventing the derivation of surface density profiles and grain-size distributions. Here, we present the most sensitive images of HL Tau obtained to date with the Karl G. Jansky Very Large Array at 7.0 mm wavelength with a spatial resolution comparable to the ALMA images. At this long wavelength, the dust emission from HL Tau is optically thin, allowing a comprehensive study of the inner disk. We obtain a total disk dust mass of (1–3) × 10 −3 M ⊙ , depending on the assumed opacity and disk temperature. Our optically thin data also indicate fast grain growth, fragmentation, and formation of dense clumps in the inner densest parts of the disk. Our results suggest that the HL Tau disk may be actually in a very early stage of planetary formation, with planets not already formed in the gaps but in the process of future formation in the bright rings

Does Flywheel Paradigm Training Improve Muscle Volume and Force? A Meta-Analysis.

Science.gov (United States)

Nuñez Sanchez, Francisco J; Sáez de Villarreal, Eduardo

2017-11-01

Núñez Sanchez, FJ and Sáez de Villarreal, E. Does flywheel paradigm training improve muscle volume and force? A meta-analysis. J Strength Cond Res 31(11): 3177-3186, 2017-Several studies have confirmed the efficacy of flywheel paradigm training for improving or benefiting muscle volume and force. A meta-analysis of 13 studies with a total of 18 effect sizes was performed to analyse the role of various factors on the effectiveness of flywheel paradigm training. The following inclusion criteria were employed for the analysis: (a) randomized studies; (b) high validity and reliability instruments; (c) published in a high quality peer-reviewed journal; (d) healthy participants; (e) studies where the eccentric programme were described; and (f) studies where increases in muscle volume and force were measured before and after training. Increases in muscle volume and force were noted through the use of flywheel systems during short periods of training. The increase in muscle mass appears was not influenced by the existence of eccentric overload during the exercise. The increase in force was significantly higher with the existence of eccentric overload during the exercise. The responses identified in this analysis are essential and should be considered by strength and conditioning professionals regarding the most appropriate dose response trends for flywheel paradigm systems to optimize the increase in muscle volume and force.

A PRIMER ON UNIFYING DEBRIS DISK MORPHOLOGIES

International Nuclear Information System (INIS)

Lee, Eve J.; Chiang, Eugene

2016-01-01

A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

A Primer on Unifying Debris Disk Morphologies

Science.gov (United States)

Lee, Eve J.; Chiang, Eugene

2016-08-01

A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

A PRIMER ON UNIFYING DEBRIS DISK MORPHOLOGIES

Energy Technology Data Exchange (ETDEWEB)

Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)

2016-08-20

A “minimum model” for debris disks consists of a narrow ring of parent bodies, secularly forced by a single planet on a possibly eccentric orbit, colliding to produce dust grains that are perturbed by stellar radiation pressure. We demonstrate how this minimum model can reproduce a wide variety of disk morphologies imaged in scattered starlight. Five broad categories of disk shape can be captured: “rings,” “needles,” “ships-and-wakes,” “bars,” and “moths (a.k.a. fans),” depending on the viewing geometry. Moths can also sport “double wings.” We explain the origin of morphological features from first principles, exploring the dependence on planet eccentricity, disk inclination dispersion, and the parent body orbital phases at which dust grains are born. A key determinant in disk appearance is the degree to which dust grain orbits are apsidally aligned. Our study of a simple steady-state (secularly relaxed) disk should serve as a reference for more detailed models tailored to individual systems. We use the intuition gained from our guidebook of disk morphologies to interpret, informally, the images of a number of real-world debris disks. These interpretations suggest that the farthest reaches of planetary systems are perturbed by eccentric planets, possibly just a few Earth masses each.

Development of flywheel systems on the basis of mechatronics. Ontwikkeling van vliegwielsysteem mechatronisch aangepakt

Energy Technology Data Exchange (ETDEWEB)

De Boer, A.

1992-05-01

Vehicles can save energy by storing the brake energy in a flywheel. So far flywheels in toys appear to be the only efficient applications. The Centre for Construction and Mechatronics (CCM) in Nuenen, Netherlands, however, is developing a flywheel system for city buses: EMAFER or Electro Mechanical Accumulator For Energy Reuse. Based on experiences with the first prototype, constructed in 1988, a second prototype will be constructed and mounted in a bus to be tested. 1 fig., 2 ills., 2 tabs.

Surface geometry of protoplanetary disks inferred from near-infrared imaging polarimetry

Energy Technology Data Exchange (ETDEWEB)

Takami, Michihiro; Hasegawa, Yasuhiro; Gu, Pin-Gao; Karr, Jennifer L.; Chapillon, Edwige; Tang, Ya-Wen [Institute of Astronomy and Astrophysics, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan, ROC (China); Muto, Takayuki [Division of Liberal Arts, Kogakuin University, 1-24-2, Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Dong, Ruobing [Nuclear Science Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Hashimoto, Jun [H. L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St. Norman, OK 73019 (United States); Kusakabe, Nobuyuki; Akiyama, Eiji; Kwon, Jungmi [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Itoh, Youchi [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, 407-2 Nishigaichi, Sayo, Sayo, Hyogo 679-5313 (Japan); Carson, Joseph [Department of Physics and Astronomy, College of Charleston, 58 Coming Street, Charleston, SC 29424 (United States); Follette, Katherine B. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Mayama, Satoshi [The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (SOKENDAI), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Sitko, Michael [Department of Physics, University of Cincinnati, Cincinnati, OH 45221 (United States); Janson, Markus [Astrophysics Research Center, Queen' s University Belfast, BT7 1NN (United Kingdom); Grady, Carol A. [Eureka Scientific, 2452 Delmer Suite 100, Oakland, CA 96402 (United States); Kudo, Tomoyuki, E-mail: hiro@asiaa.sinica.edu.tw [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); and others

2014-11-01

We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity (PI), disk inclination, assumed properties for dust scattering, and other reasonable approximations, we calculate a differential equation to derive the surface geometry. This equation is numerically integrated along the distance from the star at a given position angle. We show that, using these approximations, the local maxima in the PI distribution of spiral arms (SAO 206462, MWC 758) and rings (2MASS J16042165-2130284, PDS 70) are associated with local concave-up structures on the disk surface. We also show that the observed presence of an inner gap in scattered light still allows the possibility of a disk surface that is parallel to the light path from the star, or a disk that is shadowed by structures in the inner radii. Our analysis for rings does not show the presence of a vertical inner wall as often assumed in studies of disks with an inner gap. Finally, we summarize the implications of spiral and ring structures as potential signatures of ongoing planet formation.

Surface geometry of protoplanetary disks inferred from near-infrared imaging polarimetry

International Nuclear Information System (INIS)

Takami, Michihiro; Hasegawa, Yasuhiro; Gu, Pin-Gao; Karr, Jennifer L.; Chapillon, Edwige; Tang, Ya-Wen; Muto, Takayuki; Dong, Ruobing; Hashimoto, Jun; Kusakabe, Nobuyuki; Akiyama, Eiji; Kwon, Jungmi; Itoh, Youchi; Carson, Joseph; Follette, Katherine B.; Mayama, Satoshi; Sitko, Michael; Janson, Markus; Grady, Carol A.; Kudo, Tomoyuki

2014-01-01

We present a new method of analysis for determining the surface geometry of five protoplanetary disks observed with near-infrared imaging polarimetry using Subaru-HiCIAO. Using as inputs the observed distribution of polarized intensity (PI), disk inclination, assumed properties for dust scattering, and other reasonable approximations, we calculate a differential equation to derive the surface geometry. This equation is numerically integrated along the distance from the star at a given position angle. We show that, using these approximations, the local maxima in the PI distribution of spiral arms (SAO 206462, MWC 758) and rings (2MASS J16042165-2130284, PDS 70) are associated with local concave-up structures on the disk surface. We also show that the observed presence of an inner gap in scattered light still allows the possibility of a disk surface that is parallel to the light path from the star, or a disk that is shadowed by structures in the inner radii. Our analysis for rings does not show the presence of a vertical inner wall as often assumed in studies of disks with an inner gap. Finally, we summarize the implications of spiral and ring structures as potential signatures of ongoing planet formation.

Saturn Rings Origin: Quantum Trapping of Superconducting Iced Particles and Meissner Effect Lead to the Stable Rings System

Science.gov (United States)

Viktorovich Tchernyi, Vladimir

2018-06-01

Saturn Rings Origin: Quantum Trapping of Superconducting Iced Particles and Meissner Effect Lead to the Stable Rings System Vladimir V. Tchernyi (Cherny), Andrew Yu. Pospelov Modern Science Institute, SAIBR, Moscow, Russia. E-mail: chernyv@bk.ruAbstractIt is demonstrated how superconducting iced particles of the protoplanetary cloud of Saturn are coming to magnetic equator plane and create the stable enough rings disk. There are two steps. First, after appearance of the Saturn magnetic field due to Meissner phenomenon all particles orbits are moving to the magnetic equator plane. Finally they become distributed as rings and gaps like iron particles around magnet on laboratory table. And they are separated from each other by the magnetic field expelled from them. It takes up to few tens of thousands years with ten meters rings disk thickness. Second, due to their quantum trapping all particles become to be trapped within magnetic well at the magnetic equator plane due to Abrikosov vortex for superconductor. It works even when particles have small fraction of superconductor. During the rings evolution some contribution to the disk also could come from the collision-generated debris of the current moon and from the geysers like it happened due to magnetic coupling of Saturn and Enceladus. The rings are relict of the early days of the magnetic field of Saturn system.

Collisional dynamics of perturbed particle disks in the solar system

Science.gov (United States)

Roberts, W. W.; Stewart, G. R.

1987-01-01

Investigations of the collisional evolution of particulate disks subject to the gravitational perturbation of a more massive particle orbiting within the disk are underway. Both numerical N-body simulations using a novel collision algorithm and analytical kinetic theory are being employed to extend our understanding of perturbed disks in planetary rings and during the formation of the solar system. Particular problems proposed for investigation are: (1) The development and testing of general criteria for a small moonlet to clear a gap and produce observable morphological features in planetary rings; (2) The development of detailed models of collisional damping of the wavy edges observed on the Encke division of Saturn's A ring; and (3) The determination of the extent of runaway growth of the few largest planetesimals during the early stages of planetary accretion.

Stiffness Evaluation of High Temperature Superconductor Bearing Stiffness for 10 kWh Superconductor Flywheel Energy Storage System

International Nuclear Information System (INIS)

Park, B. J.; Jung, S. Y.; Lee, J. P.; Park, B. C.; Kim, C. H.; Han, S. C.; Du, S. G.; Han, Y. H.; Sung, T. H.

2009-01-01

A superconductor flywheel energy storage(SFES) system is mainly act an electro-mechanical battery which transfers mechanical energy into electrical form and vice versa. SFES system consists of a pair of non-contacting High Temperature Superconductor (HTS) bearings with a very low frictional loss. But it is essential to design an efficient HTS bearing considering with rotor dynamic properties through correct calculation of stiffness in order to support a huge composite flywheel rotor with high energy storage density. Static properties of HTS bearings provide data to solve problems which may occur easily in a running system. Since stiffness to counter vibration is the main parameter in designing an HTS bearing system, we investigate HTS bearing magnetic force through static properties between the Permanent Magnet(PM) and HTS. We measured axial / radial stiffness and found bearing stiffness can be easily changed by activated vibration direction between PM and HTS bulk. These results are used to determine the optimal design for a 10 kWh SFES.

Conceptual design of a moving-ring reactor

International Nuclear Information System (INIS)

Smith, A.C. Jr.; Ashworth, C.P.; Abreu, K.E.

1983-01-01

A design of a prototype Moving-Ring Reactor has been completed. The fusion fuel is confined in current-carrying rings of magnetically field-reversed plasma (''compact toroids''). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three ''burn stations''. Separator coils and a slight axial guide-field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for one third of the total burn time at each station. D-T- 3 He ice pellets refuel the rings at a rate which maintains constant radiated power. The first wall and tritium breeding blanket designs make credible use of helium cooling, SiC and Li 2 O to minimize structural radioactivity. ''Hands-on'' maintenance is possible on all reactor components outside the blanket. The first wall and blanket are designed to shut the reactor down passively in the event of a loss-of-coolant or loss-of-flow accident. Helium removes heat from the first wall, blanket and shield, and is used in a closed-cycle gas turbine to produce electricity. Energy residing in the plasma ring at the end of the burn is recovered via magnetic expansion. Electrostatic direct conversion is not used in this design. The reactor produces a constant net power of 99 MW(e). (author)

Test equipment for a flywheel energy storage system using a magnetic bearing composed of superconducting coils and superconducting bulks

International Nuclear Information System (INIS)

Ogata, M; Matsue, H; Yamashita, T; Hasegawa, H; Nagashima, K; Maeda, T; Matsuoka, T; Mukoyama, S; Shimizu, H; Horiuchi, S

2016-01-01

Energy storage systems are necessary for renewable energy sources such as solar power in order to stabilize their output power, which fluctuates widely depending on the weather. Since ‘flywheel energy storage systems’ (FWSSs) do not use chemical reactions, they do not deteriorate due to charge or discharge. This is an advantage of FWSSs in applications for renewable energy plants. A conventional FWSS has capacity limitation because of the mechanical bearings used to support the flywheel. Therefore, we have designed a superconducting magnetic bearing composed of a superconducting coil stator and a superconducting bulk rotor in order to solve this problem, and have experimentally manufactured a large scale FWSS with a capacity of 100 kWh and an output power of 300 kW. The superconducting magnetic bearing can levitate 4 tons and enables the flywheel to rotate smoothly. A performance confirmation test will be started soon. An overview of the superconducting FWSS is presented in this paper. (paper)

A compact electron storage ring design

International Nuclear Information System (INIS)

Swenson, C.A.

1992-01-01

Electron storage rings are sources of synchrotron radiation in the soft and hard parts of the x-ray spectrum. X-ray lithography is an ideal candidate technology for the production of microelectronic devices with sizes between 0.3-0.5 microns. Industrial x-ray lithography requires the x-ray source, which is the electron storage ring, to be as compact and reliable as possible. In this thesis the author reviews and develops the basic physical principles governing the design of compact electron synchrotrons for x-ray lithography. He explores the various aspects of lattice design for this application. He argues that the optimal storage ring design consists of a four fold symmetric cell lattice with two quadrupole families and 90 degrees zero gradient dipole magnets. It is demonstrated that radiation requirements for lithography and the use of zero gradient magnetic dipole fields constrains the lattice to four or more dipole magnets. The author develops a lattice design for x-ray lithography following this logic. He then develops a dipole magnet design for a machine using this lattice. Particle tracking data is integrated into the magnet design and used to optimize the end coil configurations of the magnets. The author then reviews the magnet's physical construction and measurement. He develops a cryogenic Hall probe mapping apparatus for this magnet and measure its excitation curves

PLANETARY CONSTRUCTION ZONES IN OCCULTATION: DISCOVERY OF AN EXTRASOLAR RING SYSTEM TRANSITING A YOUNG SUN-LIKE STAR AND FUTURE PROSPECTS FOR DETECTING ECLIPSES BY CIRCUMSECONDARY AND CIRCUMPLANETARY DISKS

Energy Technology Data Exchange (ETDEWEB)

Mamajek, Eric E.; Quillen, Alice C.; Pecaut, Mark J.; Moolekamp, Fred; Scott, Erin L. [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627-0171 (United States); Kenworthy, Matthew A. [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Cameron, Andrew Collier; Parley, Neil R. [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom)

2012-03-15

The large relative sizes of circumstellar and circumplanetary disks imply that they might be seen in eclipse in stellar light curves. We estimate that a survey of {approx}10{sup 4} young ({approx}10 million year old) post-accretion pre-main-sequence stars monitored for {approx}10 years should yield at least a few deep eclipses from circumplanetary disks and disks surrounding low-mass companion stars. We present photometric and spectroscopic data for a pre-main-sequence K5 star (1SWASP J140747.93-394542.6 = ASAS J140748-3945.7), a newly discovered {approx}0.9 M{sub Sun} member of the {approx}16 Myr old Upper Centaurus-Lupus subgroup of Sco-Cen at a kinematic distance of 128 {+-} 13 pc. This star exhibited a remarkably long, deep, and complex eclipse event centered on 2007 April 29 (as discovered in Super Wide Angle Search for Planets (SuperWASP) photometry, and with portions of the dimming confirmed by All Sky Automated Survey (ASAS) data). At least five multi-day dimming events of >0.5 mag are identified, with a >3.3 mag deep eclipse bracketed by two pairs of {approx}1 mag eclipses symmetrically occurring {+-}12 days and {+-}26 days before and after. Hence, significant dimming of the star was taking place on and off over at least a {approx}54 day period in 2007, and a strong >1 mag dimming event occurring over a {approx}12 day span. We place a firm lower limit on the period of 850 days (i.e., the orbital radius of the eclipser must be >1.7 AU and orbital velocity must be <22 km s{sup -1}). The shape of the light curve is similar to the lopsided eclipses of the Be star EE Cep. We suspect that this new star is being eclipsed by a low-mass object orbited by a dense inner disk, further girded by at least three dusty rings of optical depths near unity. Between these rings are at least two annuli of near-zero optical depth (i.e., gaps), possibly cleared out by planets or moons, depending on the nature of the secondary. For possible periods in the range 2.33-200 yr, the

Design, Fabrication, and Testing of the INSTAR [INertial STorage And Recovery] System: A Flywheel-based, High Power Energy Storage System for Improved Hybrid Vehicle Fuel Efficiency

OpenAIRE

Talancon, Daniel Raul

2015-01-01

This thesis describes the development of the INSTAR system: a high-power, cost-effective energy storage system designed to improve HEV regenerative braking capabilities by combining chemical batteries with an electromechanical flywheel. This combination allows the regenerative braking system in hybrid vehicles to recapture more available braking energy at a lower battery pack charging current, increasing vehicle energy efficiency while also potentially increasing battery life.A prototype flyw...

Fault detection of flywheel system based on clustering and principal component analysis

Directory of Open Access Journals (Sweden)

Wang Rixin

2015-12-01

Full Text Available Considering the nonlinear, multifunctional properties of double-flywheel with closed-loop control, a two-step method including clustering and principal component analysis is proposed to detect the two faults in the multifunctional flywheels. At the first step of the proposed algorithm, clustering is taken as feature recognition to check the instructions of “integrated power and attitude control” system, such as attitude control, energy storage or energy discharge. These commands will ask the flywheel system to work in different operation modes. Therefore, the relationship of parameters in different operations can define the cluster structure of training data. Ordering points to identify the clustering structure (OPTICS can automatically identify these clusters by the reachability-plot. K-means algorithm can divide the training data into the corresponding operations according to the reachability-plot. Finally, the last step of proposed model is used to define the relationship of parameters in each operation through the principal component analysis (PCA method. Compared with the PCA model, the proposed approach is capable of identifying the new clusters and learning the new behavior of incoming data. The simulation results show that it can effectively detect the faults in the multifunctional flywheels system.

Effect of the Shrink Fit and Mechanical Tolerance on Reactor Coolant Pump Flywheel Integrity Evaluation

Energy Technology Data Exchange (ETDEWEB)

Kim, Donghak [Korea KHNP Central Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Reactor coolant pump (RCP) flywheel should satisfy the RCP flywheel integrity criteria of the US NRC standard review plan (SRP) 5.4.1.1 and regulatory guide (RG) 1.14. Shrink-fit and rotational stresses should be calculated to evaluate the integrity. In this paper the effects of the shrink fit and mechanical tolerance on the RCP flywheel integrity evaluation are studied. The shrink fit should be determined by the joint release speed and the stresses in the flywheel will be increased by the shrink fit. The stress at the interface between the hub and the outer wheel shows the highest value. The effect of the mechanical tolerance should be considered for the stress evaluation. And the effect of the mechanical tolerance should be not considered to determine the joint release speed.

Effect of the Shrink Fit and Mechanical Tolerance on Reactor Coolant Pump Flywheel Integrity Evaluation

International Nuclear Information System (INIS)

Kim, Donghak

2015-01-01

Reactor coolant pump (RCP) flywheel should satisfy the RCP flywheel integrity criteria of the US NRC standard review plan (SRP) 5.4.1.1 and regulatory guide (RG) 1.14. Shrink-fit and rotational stresses should be calculated to evaluate the integrity. In this paper the effects of the shrink fit and mechanical tolerance on the RCP flywheel integrity evaluation are studied. The shrink fit should be determined by the joint release speed and the stresses in the flywheel will be increased by the shrink fit. The stress at the interface between the hub and the outer wheel shows the highest value. The effect of the mechanical tolerance should be considered for the stress evaluation. And the effect of the mechanical tolerance should be not considered to determine the joint release speed

Innovative opto-mechanical design of a laser head for compact thin-disk

Science.gov (United States)

Macúchová, Karolina; Smrž, Martin; Řeháková, Martina; Mocek, Tomáš

2016-11-01

We present recent progress in design of innovative versatile laser head for lasers based on thin-disk architecture which are being constructed at the HiLASE centre of the IOP in the Czech Republic. Concept of thin-disk laser technology allows construction of lasers providing excellent beam quality with high average output power and optical efficiency. Our newly designed thin-disk carrier and pump module comes from optical scheme consisting of a parabolic mirror and roof mirrors proposed in 90's. However, mechanical parts and a cooling system were in-house simplified and tailor-made to medium power lasers since no suitable setup was commercially available. Proposed opto-mechanical design is based on stable yet easily adjustable mechanics. The only water nozzle-cooled component is a room-temperature-operated thindisk mounted on a special cooling finger. Cooling of pump optics was replaced by heat conductive transfer from mirrors made of special Al alloy to a massive brass baseplate. Such mirrors are easy to manufacture and very cheap. Presented laser head was manufactured and tested in construction of Er and Yb doped disk lasers. Details of the latest design will be presented.

A design of a quasi-isochronous storage ring

International Nuclear Information System (INIS)

Lee, S.Y.; Trbojevic, D.

1993-07-01

Isochronous electron storage rings may offer advantages for future high luminosity meson factories. A Quasi-isochronous lattice based on the design principle of flexible γτ lattice is studied. The emittance and chromatic properties of such a lattice are studied. Applications of this design techniques for electron storage rings will be discussed

Interlayer toughening of fiber composite flywheel rotors

Science.gov (United States)

Groves, Scott E.; Deteresa, Steven J.

1998-01-01

An interlayer toughening mechanism to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0.degree. to 90.degree. to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles.

A NEW ALGORITHM FOR SELF-CONSISTENT THREE-DIMENSIONAL MODELING OF COLLISIONS IN DUSTY DEBRIS DISKS

International Nuclear Information System (INIS)

Stark, Christopher C.; Kuchner, Marc J.

2009-01-01

We present a new 'collisional grooming' algorithm that enables us to model images of debris disks where the collision time is less than the Poynting-Robertson (PR) time for the dominant grain size. Our algorithm uses the output of a collisionless disk simulation to iteratively solve the mass flux equation for the density distribution of a collisional disk containing planets in three dimensions. The algorithm can be run on a single processor in ∼1 hr. Our preliminary models of disks with resonant ring structures caused by terrestrial mass planets show that the collision rate for background particles in a ring structure is enhanced by a factor of a few compared to the rest of the disk, and that dust grains in or near resonance have even higher collision rates. We show how collisions can alter the morphology of a resonant ring structure by reducing the sharpness of a resonant ring's inner edge and by smearing out azimuthal structure. We implement a simple prescription for particle fragmentation and show how PR drag and fragmentation sort particles by size, producing smaller dust grains at smaller circumstellar distances. This mechanism could cause a disk to look different at different wavelengths, and may explain the warm component of dust interior to Fomalhaut's outer dust ring seen in the resolved 24 μm Spitzer image of this system.

One-dimensional disk model simulation for klystron design

International Nuclear Information System (INIS)

Yonezawa, H.; Okazaki, Y.

1984-05-01

In 1982, one of the authors (Okazaki), of Toshiba Corporation, wrote a one-dimensional, rigid-disk model computer program to serve as a reliable design tool for the 150 MW klystron development project. This is an introductory note for the users of this program. While reviewing the so-called disk programs presently available, hypotheses such as gridded interaction gaps, a linear relation between phase and position, and so on, were found. These hypotheses bring serious limitations and uncertainties into the computational results. JPNDISK was developed to eliminate these defects, to follow the equations of motion as rigorously as possible, and to obtain self-consistent solutions for the gap voltages and the electron motion. Although some inaccuracy may be present in the relativistic region, JPNDISK, in its present form, seems a most suitable tool for klystron design; it is both easy and inexpensive to use

Design Issues of the Pre-Compression Rings of Iter

Science.gov (United States)

Knaster, J.; Baker, W.; Bettinali, L.; Jong, C.; Mallick, K.; Nardi, C.; Rajainmaki, H.; Rossi, P.; Semeraro, L.

2010-04-01

The pre-compression system is the keystone of ITER. A centripetal force of ˜30 MN will be applied at cryogenic conditions on top and bottom of each TF coil. It will prevent the `breathing effect' caused by the bursting forces occurring during plasma operation that would affect the machine design life of 30000 cycles. Different alternatives have been studied throughout the years. There are two major design requirements limiting the engineering possibilities: 1) the limited available space and 2) the need to hamper eddy currents flowing in the structures. Six unidirectionally wound glass-fibre composite rings (˜5 m diameter and ˜300 mm cross section) are the final design choice. The rings will withstand the maximum hoop stresses machine operation. The present paper summarizes the pre-compression ring R&D carried out during several years. In particular, we will address the composite choice and mechanical characterization, assessment of creep or stress relaxation phenomena, sub-sized rings testing and the optimal ring fabrication processes that have led to the present final design.

Magnetic bearing flywheels for electric storage

Energy Technology Data Exchange (ETDEWEB)

Poubeau, P C

1981-01-01

A magnetic bearing flywheel was designed. In order to have a simple, reliable system, magnetic suspension with a single servoloop for one degree of freedom of the rotor was used, four other degrees of freedom being controlled passively and the sixth one, corresponding to the rotation axis. The motor that transfers electric energy to the rotor is of the ironless brushless dc type with electronic commutation. It is operated alternatively for accelerating the wheel and then as a generator for delivering the stored energy. The use of high stress composite materials in the rotor greatly increases the operational limits of this equipment. Key characteristics of kinetic energy storage are mentioned along with a wide range of applications. Besides energy storage for satellites, these include power smoothing for solar and wind energy systems as well as backup power supplies, e.g., for electric vehicles.

Colliding and merging galaxies. II. S0 galaxies with polar rings

International Nuclear Information System (INIS)

Schweizer, F.; Whitmore, B.D.; Rubin, V.C.

1983-01-01

We first present a detailed optical study of A0136-0801, a 16 1/2 -mag ''spindle'' galaxy girdled by a ring of gas, dust, and young stars. The spindle is a normal S0 disk seen nearly edge-on, as shown by its photometric profile and fast rotation (v/sub rot//sigma/sub v/ = 2.2); a prolate structure seems to be ruled out. The surrounding ring runs over the poles of this S0 disk and serves as a probe of the vertical potential. The ring motions suggest that a massive halo extends far beyond the S0 disk (out to 3R 25 ) and that this halo is more nearly spherical than flat. We then list 22 related galaxies and derive that a few percent of all field S0's possess near-polar rings or disks. We suggest that these structures are due to a second event, most likely the transfer of mass from a companion galaxy during a close encounter and occasionally also the merger of a companion. Although accretion occurs presumably at random angles, polar rings are favored statistically because of their slow differential precession and consequent longevity. Alternate evolutionary schemes are also discussed. Finally, we suggest that M82 may be forming a polar ring from former M81 material, and predict that the ''tilted bulge'' of UGC 7576 is an S0 disk seen nearly edge-on

[Hydrodynamics of disk artificial heart valves with different design characteristics].

Science.gov (United States)

Dobrova, N B; Zaretskiĭ, Iu V

1989-01-01

Bench tests for 38 models of artificial heart valves (AHV) with different design parameters allowed us to decide in favour of the valves with reduced eccentricity (compared to the serial AHV of the EMAHV type) according to its resistance in the constant flow. Out of the compatibility checks of the design parameters tested it was concluded that the disk did not make the complete calculated angle when rotated. The dependence of AHV resistance on the disk rotation angle showed that there is no necessity to increase that angle more than 70 degrees for the mitral valve and more than 75 degrees for the aortic AHV.

Scanning Ultrasonic Spectroscopy System Developed for the Inspection of Composite Flywheels

Science.gov (United States)

Martin, Richard E.; Baaklini, George Y.

2002-01-01

Composite flywheels are being considered as replacements for chemical batteries aboard the International Space Station. A flywheel stores energy in a spinning mass that can turn a generator to meet power demands. Because of the high rotational speeds of the spinning mass, extensive testing of the flywheel system must be performed prior to flight certification. With this goal in mind, a new scanning system has been developed at the NASA Glenn Research Center for the nondestructive inspection of composite flywheels and flywheel subcomponents. The system uses ultrasonic waves to excite a material and examines the response to detect and locate flaws and material variations. The ultrasonic spectroscopy system uses a transducer to send swept-frequency ultrasonic waves into a test material and then receives the returning signal with a second transducer. The received signal is then analyzed in the frequency domain using a fast Fourier transform. A second fast Fourier transform is performed to examine the spacing of the peaks in the frequency domain. The spacing of the peaks is related to the standing wave resonances that are present in the material because of the constructive and destructive interferences of the waves in the full material thickness as well as in individual layers within the material. Material variations and flaws are then identified by changes in the amplitudes and positions of the peaks in both the frequency and resonance spacing domains. This work, conducted under a grant through the Cleveland State University, extends the capabilities of an existing point-by-point ultrasonic spectroscopy system, thus allowing full-field automated inspection. Results of an ultrasonic spectroscopy scan of a plastic cylinder with intentionally seeded flaws. The result of an ultrasonic spectroscopy scan of a plastic cylinder used as a proof-of-concept specimen is shown. The cylinder contains a number of flat bottomed holes of various sizes and shapes. The scanning system

Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

Energy Technology Data Exchange (ETDEWEB)

Miller, John; Sibley, Lewis, B.; Wohlgemuth, John

1999-06-01

This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs.

Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

International Nuclear Information System (INIS)

Miller, John; Sibley Lewis, B.; Wohlgemuth, John

1999-01-01

This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs

Dynamics of dense particle disks

International Nuclear Information System (INIS)

Araki, S.; Tremaine, S.; Toronto Univ., Canada)

1986-01-01

The present investigation of mechanical equilibrium and collisional transport processes in dense, differentially rotating particle disks is based on the Enskog (1922) theory of dense, hard sphere gases, with the single exception that the spheres are inelastic. The viscous instability suggested as a source of Saturn B ring structure does not arise in the models presented, although the ring may be subject to a phase transition analogous to the liquid-solid transition observed in molecular dynamics simulations of elastic hard spheres. In such a case, the ring would alternately exhibit zero-shear, or solid, and high shear, or liquid, zones. 29 references

Electrifying the disk: a modular rotating platform for wireless power and data transmission for Lab on a disk application.

Science.gov (United States)

Höfflin, Jens; Torres Delgado, Saraí M; Suárez Sandoval, Fralett; Korvink, Jan G; Mager, Dario

2015-06-21

We present a design for wireless power transfer, via inductively coupled coils, to a spinning disk. The rectified and stabilised power feeds an Arduino-compatible microcontroller (μC) on the disc, which in turn drives and monitors various sensors and actuators. The platform, which has been conceived to flexibly prototype such systems, demonstrates the feasibility of a wireless power supply and the use of a μC circuit, for example for Lab-on-a-disk applications, thereby eliminating the need for cumbersome slip rings or batteries, and adding a cogent and new degree of freedom to the setup. The large number of sensors and actuators included demonstrate that a wide range of physical parameters can be easily monitored and altered. All devices are connected to the μC via an I(2)C bus, therefore can be easily exchanged or augmented by other devices in order to perform a specific task on the disk. The wireless power supply takes up little additional physical space and should work in conjunction with most existing Lab-on-a-disk platforms as a straightforward add-on, since it does not require modification of the rotation axis and can be readily adapted to specific geometrical requirements.

Design and Finite Element Analysis of a Novel Transverse Flux Permanent Magnet Disk Generator

DEFF Research Database (Denmark)

Hosseini, Seyedmohsen; Moghani, Javad Shokrollahi; Ershad, Nima Farrokhzad

2011-01-01

This paper presents a novel structure of a transverse flux permanent magnet disk generator. The proposed disk shape structure simplifies prototyping by using simple laminated steel sheets in comparison with previous transverse flux structures that employ bent laminations and soft magnetic...... composites. Also the proposed structure has a higher power factor than what has been reported previously for transverse flux permanent magnet structures. After introducing the transverse flux permanent magnet disk generator, the design process is explained and a small power generator is designed...

EARTH, MOON, SUN, AND CV ACCRETION DISKS

International Nuclear Information System (INIS)

Montgomery, M. M.

2009-01-01

Net tidal torque by the secondary on a misaligned accretion disk, like the net tidal torque by the Moon and the Sun on the equatorial bulge of the spinning and tilted Earth, is suggested by others to be a source to retrograde precession in non-magnetic, accreting cataclysmic variable (CV) dwarf novae (DN) systems that show negative superhumps in their light curves. We investigate this idea in this work. We generate a generic theoretical expression for retrograde precession in spinning disks that are misaligned with the orbital plane. Our generic theoretical expression matches that which describes the retrograde precession of Earths' equinoxes. By making appropriate assumptions, we reduce our generic theoretical expression to those generated by others, or to those used by others, to describe retrograde precession in protostellar, protoplanetary, X-ray binary, non-magnetic CV DN, quasar, and black hole systems. We find that spinning, tilted CV DN systems cannot be described by a precessing ring or by a precessing rigid disk. We find that differential rotation and effects on the disk by the accretion stream must be addressed. Our analysis indicates that the best description of a retrogradely precessing spinning, tilted, CV DN accretion disk is a differentially rotating, tilted disk with an attached rotating, tilted ring located near the innermost disk annuli. In agreement with the observations and numerical simulations by others, we find that our numerically simulated CV DN accretion disks retrogradely precess as a unit. Our final, reduced expression for retrograde precession agrees well with our numerical simulation results and with selective observational systems that seem to have main-sequence secondaries. Our results suggest that a major source to retrograde precession is tidal torques like that by the Moon and the Sun on the Earth. In addition, these tidal torques should be common to a variety of systems where one member is spinning and tilted, regardless if

STELLAR NUCLEI AND INNER POLAR DISKS IN LENTICULAR GALAXIES

Energy Technology Data Exchange (ETDEWEB)

Sil’chenko, Olga K., E-mail: olga@sai.msu.su [Sternberg Astronomical Institute, M.V. Lomonosov Moscow State University, Moscow, 119992 (Russian Federation); Isaac Newton Institute, Chile, Moscow Branch (Chile)

2016-09-01

I analyze statistics of the stellar population properties for stellar nuclei and bulges of nearby lenticular galaxies in different environments by using panoramic spectral data of the integral-field spectrograph SAURON retrieved from the open archive of the Isaac Newton Group. I also estimate the fraction of nearby lenticular galaxies having inner polar gaseous disks by exploring the volume-limited sample of early-type galaxies of the ATLAS-3D survey. By inspecting the two-dimensional velocity fields of the stellar and gaseous components with the running tilted-ring technique, I have found seven new cases of inner polar disks. Together with those, the frequency of inner polar disks in nearby S0 galaxies reaches 10%, which is much higher than the frequency of large-scale polar rings. Interestingly, the properties of the nuclear stellar populations in the inner polar ring hosts are statistically the same as those in the whole S0 sample, implying similar histories of multiple gas-accretion events from various directions.

STELLAR NUCLEI AND INNER POLAR DISKS IN LENTICULAR GALAXIES

International Nuclear Information System (INIS)

Sil’chenko, Olga K.

2016-01-01

I analyze statistics of the stellar population properties for stellar nuclei and bulges of nearby lenticular galaxies in different environments by using panoramic spectral data of the integral-field spectrograph SAURON retrieved from the open archive of the Isaac Newton Group. I also estimate the fraction of nearby lenticular galaxies having inner polar gaseous disks by exploring the volume-limited sample of early-type galaxies of the ATLAS-3D survey. By inspecting the two-dimensional velocity fields of the stellar and gaseous components with the running tilted-ring technique, I have found seven new cases of inner polar disks. Together with those, the frequency of inner polar disks in nearby S0 galaxies reaches 10%, which is much higher than the frequency of large-scale polar rings. Interestingly, the properties of the nuclear stellar populations in the inner polar ring hosts are statistically the same as those in the whole S0 sample, implying similar histories of multiple gas-accretion events from various directions.

SMACK: A New Algorithm for Modeling Collisions and Dynamics of Planetesimals in Debris Disks

Science.gov (United States)

Nesvold, Erika Rose; Kuchner, Marc J.; Rein, Hanno; Pan, Margaret

2013-01-01

We present the Superparticle Model/Algorithm for Collisions in Kuiper belts and debris disks (SMACK), a new method for simultaneously modeling, in 3-D, the collisional and dynamical evolution of planetesimals in a debris disk with planets. SMACK can simulate azimuthal asymmetries and how these asymmetries evolve over time. We show that SMACK is stable to numerical viscosity and numerical heating over 10(exp 7) yr, and that it can reproduce analytic models of disk evolution. We use SMACK to model the evolution of a debris ring containing a planet on an eccentric orbit. Differential precession creates a spiral structure as the ring evolves, but collisions subsequently break up the spiral, leaving a narrower eccentric ring.

The Fine Structure of Herman Rings

DEFF Research Database (Denmark)

Fagella, Nuria; Henriksen, Christian

2017-01-01

We study the geometric structure of the boundary of Herman rings in a model family of Blaschke products of degree 3 (up to quasiconformal deformation). Shishikura’s quasiconformal surgery relates the Herman ring to the Siegel disk of a quadratic polynomial. By studying the regularity properties...

A Flywheel Energy Storage System Based on a Doubly Fed Induction Machine and Battery for Microgrid Control

Directory of Open Access Journals (Sweden)

Thai-Thanh Nguyen

2015-06-01

Full Text Available Microgrids are eco-friendly power systems because they use renewable sources such as solar and wind power as the main power source. However, the stochastic nature of wind and solar power is a considerable challenge for the efficient operation of microgrids. Microgrid operations have to satisfy quality requirements in terms of the frequency and voltage. To overcome these problems, energy storage systems for short- and long-term storage are used with microgrids. Recently, the use of short-term energy storage systems such as flywheels has attracted significant interest as a potential solution to this problem. Conventional flywheel energy storage systems exhibit only one control mode during operation: either smoothing wind power control or frequency control. In this paper, we propose a new flywheel energy storage system based on a doubly fed induction machine and a battery for use with microgrids. The new flywheel energy storage system can be used not only to mitigate wind power fluctuations, but also to control the frequency as well as the voltage of the microgrid during islanded operation. The performance of the proposed flywheel energy storage system is investigated through various simulations using MATLAB/Simulink software. In addition, a conventional flywheel energy storage system based on a doubly fed induction machine is simulated and its performance compared with that of the proposed one.

Conceptual design of a moving-ring reactor

International Nuclear Information System (INIS)

Smith, A.C.; Carlson, G.A.; Ashworth, C.P.

1986-01-01

A design of a prototype moving-ring reactor was completed, and a development plan for a pilot reactor is outlined. The fusion fuel is confined in current-carrying rings of magnetically field-reversed plasma (''compact toroids''). The plasma rings, formed by a coaxial plasma gun, undergo adiabatic magnetic compression to ignition temperature while they are being injected into the reactor's burner section. The cylindrical burner chamber is divided into three ''burn stations.'' Separator coils and a slight axial guide field gradient are used to shuttle the ignited toroids rapidly from one burn station to the next, pausing for one-third of the total burn time at each station. Deuterium-tritium- 3 He ice pellets refuel the rings at a rate that maintains constant radiated power. The fusion power per ring is approx. =105.5 MW. The burn time to reach a fusion energy gain of Q = 30 is 5.9 s

Effect of design factors on surface temperature and wear in disk brakes

Science.gov (United States)

Santini, J. J.; Kennedy, F. E.; Ling, F. F.

1976-01-01

The temperatures, friction, wear and contact conditions that occur in high energy disk brakes are studied. Surface and near surface temperatures were monitored at various locations in a caliper disk brake during drag type testing, with friction coefficient and wear rates also being determined. The recorded transient temperature distributions in the friction pads and infrared photographs of the rotor disk surface both showed that contact at the friction surface was not uniform, with contact areas constantly shifting due to nonuniform thermal expansion and wear. The effect of external cooling and of design modifications on friction, wear and temperatures was also investigated. It was found that significant decreases in surface temperature and in wear rate can be achieved without a reduction in friction either by slotting the contacting face of the brake pad or by modifying the design of the pad support to improve pad compliance. Both design changes result in more uniform contact conditions on the friction surface.

Reactor coolant pump motors manufacturing capability and references

International Nuclear Information System (INIS)

Baudin, Patyrick

2008-01-01

Flywheel: - Main inertia of the RCP rotor: - 2 disks, shrunk to the upper side of the shaft, driven in rotation by 3 keys. - Material: rolling A533 grade B class 1 low alloy steel plates - Major inertia of the RCP rotor (Allows a slow shut down of the RCP). - Centered by the runner collar in normal operating conditions. - Designed to withstand over-speed of 1.25 x nominal rotating speed. - Easy periodic ultrasonic inspection without disassembly of the flywheel and/or removal of the motor. Anti-reverse rotation device: Prevents reverse rotation of shaft-line when RCP is stopped and others running. 5 forged pawls assembled on the flywheel outside diameter. Ratchet plate with shock absorbers and springs. Operation: Pawls are maintained lifted by centrifugal effect since N > 150 rpm. During RCP shut-down, as N < 150 rpm pawls drop on the ratchet plate prevents reverse-rotation due to reverse torque. Inertia effects are limited by shock-absorbers. Double thrust bearing 'Kings bury' type designed to support loads of about 60 tons 8 babbit ted steel shoes with temperature sensors, equalizing pads distribute equal axial load on each shoe, designed to withstand normal, transient and incidental loading conditions. Viscosity pump ensure continuous oil lubrication and oil circulation to cooler. Instrumentation: shoes temperature (167 .deg. F max). High pressure oil pump provides an oil film between runner and shoes before and during RCP start-up and shut-down. Secondary function: oil spray into the upper guide bearing. Characteristics: minimum oil injection pressure 610 psi. Upper guide bearing 8 babbit ted steel shoes. Preloaded shoes to improve the vibratory behavior. Lubricated by oil. Oil capacity: ± 240 gallons. Magnetic core made of high silicon steel sheets, insulated on both sides with 'ALKOPHOS' Stacks of sheets are periodically spaced by vent spacers Winding made of rectangular section copper bars, insulated with mica tape Vacuum impregnation with epoxy resin End

Reactor coolant pump motors manufacturing capability and references

Energy Technology Data Exchange (ETDEWEB)

Baudin, Patyrick [AREVA NP, Paris (France)

2008-04-15

Flywheel: - Main inertia of the RCP rotor: - 2 disks, shrunk to the upper side of the shaft, driven in rotation by 3 keys. - Material: rolling A533 grade B class 1 low alloy steel plates - Major inertia of the RCP rotor (Allows a slow shut down of the RCP). - Centered by the runner collar in normal operating conditions. - Designed to withstand over-speed of 1.25 x nominal rotating speed. - Easy periodic ultrasonic inspection without disassembly of the flywheel and/or removal of the motor. Anti-reverse rotation device: Prevents reverse rotation of shaft-line when RCP is stopped and others running. 5 forged pawls assembled on the flywheel outside diameter. Ratchet plate with shock absorbers and springs. Operation: Pawls are maintained lifted by centrifugal effect since N > 150 rpm. During RCP shut-down, as N < 150 rpm pawls drop on the ratchet plate prevents reverse-rotation due to reverse torque. Inertia effects are limited by shock-absorbers. Double thrust bearing 'Kings bury' type designed to support loads of about 60 tons 8 babbit ted steel shoes with temperature sensors, equalizing pads distribute equal axial load on each shoe, designed to withstand normal, transient and incidental loading conditions. Viscosity pump ensure continuous oil lubrication and oil circulation to cooler. Instrumentation: shoes temperature (167 .deg. F max). High pressure oil pump provides an oil film between runner and shoes before and during RCP start-up and shut-down. Secondary function: oil spray into the upper guide bearing. Characteristics: minimum oil injection pressure 610 psi. Upper guide bearing 8 babbit ted steel shoes. Preloaded shoes to improve the vibratory behavior. Lubricated by oil. Oil capacity: {+-} 240 gallons. Magnetic core made of high silicon steel sheets, insulated on both sides with 'ALKOPHOS' Stacks of sheets are periodically spaced by vent spacers Winding made of rectangular section copper bars, insulated with mica tape Vacuum impregnation

Performance Analysis of a Flywheel Energy Storage System

Directory of Open Access Journals (Sweden)

K. Ghedamsi

2008-06-01

Full Text Available The flywheel energy storage systems (FESSs are suitable for improving the quality of the electric power delivered by the wind generators and to help these generators to contribute to the ancillary services. In this paper, a flywheel energy storage system associated to a grid connected variable speed wind generation (VSWG scheme using a doubly fed induction generator (DFIG is investigated. Therefore, the dynamic behavior of a wind generator, including models of the wind turbine (aerodynamic, DFIG, matrix converter, converter control (algorithm of VENTURINI and power control is studied. This paper investigates also, the control method of the FESS with a classical squirrel-cage induction machine associated to a VSWG using back-to-back AC/AC converter. Simulation results of the dynamic models of the wind generator are presented, for different operating points, to show the good performance of the proposed system.

Accumulator ring design for the NSNS project

International Nuclear Information System (INIS)

Weng, W.T.; Alessi, J.; Beebe-Wang, J.

1997-01-01

The goal of the proposed National Spallation Neutron Source (NSNS) is to provide a short pulse proton beam of about 0.5 μs with average beam power of 1 MW. To achieve such purpose, a proton storage ring operated at 60 Hz with 1 x 10 14 protons per pulse at 1 GeV is required. The Accumulator Ring (AR) receives 1 msec long H - beam bunches of 28 mA from a 1 GeV linac. Scope and design performance goals of the AR are presented, other possible technological choices and design options considered, but not adopted, are also briefly reviewed

MUSE observations of the counter-rotating nuclear ring in NGC 7742

Science.gov (United States)

Martinsson, Thomas P. K.; Sarzi, Marc; Knapen, Johan H.; Coccato, Lodovico; Falcón-Barroso, Jesús; Elmegreen, Bruce G.; de Zeeuw, Tim

2018-04-01

Aims: We present results from MUSE observations of the nearly face-on disk galaxy NGC 7742. This galaxy hosts a spectacular nuclear ring of enhanced star formation, which is unusual in that it is hosted by a non-barred galaxy, and because this star formation is most likely fuelled by externally accreted gas that counter-rotates with respect to its main stellar body. Methods: We used the MUSE data to derive the star-formation history (SFH) and accurately measure the stellar and ionized-gas kinematics of NGC 7742 in its nuclear, bulge, ring, and disk regions. Results: We have mapped the previously known gas counter-rotation well outside the ring region and deduce the presence of a slightly warped inner disk, which is inclined at approximately 6° compared to the outer disk. The gas-disk inclination is well constrained from the kinematics; the derived inclination 13.7° ± 0.4° agrees well with that derived from photometry and from what one expects using the inverse Tully-Fisher relation. We find a prolonged SFH in the ring with stellar populations as old as 2-3 Gyr and an indication that the star formation triggered by the minor merger event was delayed in the disk compared to the ring. There are two separate stellar components: an old population that counter-rotates with the gas, and a young one, concentrated to the ring, that co-rotates with the gas. We recover the kinematics of the old stars from a two-component fit, and show that combining the old and young stellar populations results in the erroneous average velocity of nearly zero found from a one-component fit. Conclusions: The spatial resolution and field of view of MUSE allow us to establish the kinematics and SFH of the nuclear ring in NGC 7742. We show further evidence that this ring has its origin in a minor merger event, possibly 2-3 Gyr ago. Data used for the flux and kinematic maps (Figs. 1 and 3-5) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or

Experimental Performance Evaluation of a High Speed Permanent Magnet Synchronous Motor and Drive for a Flywheel Application at Different Frequencies

Science.gov (United States)

Nagorny, Aleksandr S.; Jansen, Ralph H.; Kankam, M. David

2007-01-01

This paper presents the results of an experimental performance characterization study of a high speed, permanent magnet motor/generator (M/G) and drive applied to a flywheel module. Unlike the conventional electric machine the flywheel M/G is not a separated unit; its stator and rotor are integrated into a flywheel assembly. The M/G rotor is mounted on a flywheel rotor, which is magnetically levitated and sealed within a vacuum chamber during the operation. Thus, it is not possible to test the M/G using direct load measurements with a dynamometer and torque transducer. Accordingly, a new in-situ testing method had to be developed. The paper describes a new flywheel M/G and drive performance evaluation technique, which allows the estimation of the losses, efficiency and power quality of the flywheel high speed permanent magnet M/G, while working in vacuum, over wide frequency and torque ranges. This method does not require any hardware modification nor any special addition to the test rig. This new measurement technique is useful for high-speed applications, when applying an external load is technically difficult.

Polarimetry and Flux Distribution in the Debris Disk Around HD 32297

Science.gov (United States)

Asensio-Torres, R.; Janson, M.; Hashimoto, J.; Thalmann, C.; Currie, T.; Buenzli,; Kudo, T.; Kuzuhara, M.; Kusakabe, N.; Akiyama, E.;

Research and development project for flywheel energy storage system using high-temperature superconducting magnetic bearing

International Nuclear Information System (INIS)

Shinagawa, Jiro; Ishikawa, Fumihiko

1996-01-01

Recent progress in the research and development of an yttrium-based oxide high-temperature superconductor has enabled the production of a large-diameter bulk with a strong flux-pinning force. A combination of this superconductor and a permanent magnet makes it feasible to fabricate a non-contact, non-controlled superconducting magnetic bearing with a very small rotational loss. Use of the superconducting magnetic bearing for a flywheel energy storage system may pave the way to the development of a new energy storage system that has great energy storage efficiency. >From relevant data measured with a miniature model of the high-temperature superconducting magnetic bearing, a conceptual design of an 8 MWh flywheel energy storage system was developed, using the new bearing which proved to be potentially capable of achieving a high energy storage efficiency of 84%. A 100 Wh-class experimental system was install that attained a high revolution rate of 17.000 rpm. (author)

Direct rotating ring-disk measurement of the sodium borohydride diffusion coefficient in sodium hydroxide solutions

Energy Technology Data Exchange (ETDEWEB)

Chatenet, M. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France)], E-mail: Marian.Chatenet@phelma.grenoble-inp.fr; Molina-Concha, M.B. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France); El-Kissi, N. [Laboratoire de Rheologie, UMR 5520 CNRS/Grenoble-INP/UJF, 1301 rue de la piscine, 38041 Grenoble Cedex 9 (France); Parrour, G.; Diard, J.-P. [Laboratoire d' Electrochimie et de Physico-chimie des Materiaux et des Interfaces, LEPMI, UMR 5631 CNRS/Grenoble-INP/UJF, 1130 rue de la piscine, BP75, 38402 Saint Martin d' Heres Cedex (France)

2009-07-15

This paper presents the experimental determination of the diffusion coefficient of borohydride anion and solution kinematic viscosity for a large panel of NaOH + NaBH{sub 4} electrolytic solutions relevant for use as anolyte in Direct Borohydride Fuel Cells (DBFC). The diffusion coefficients have been measured by the transit-time technique on gold rotating ring-disk electrodes, and verified using other classical techniques reported in the literature, namely the Levich method and Electrochemical Impedance Spectroscopy on a gold RDE, or chronoamperometry at a gold microdisk. The agreement between these methods is generally good. The diffusion coefficients measured from the RRDE technique are however ca. twice larger than those previously reported in the literature (e.g. ca. 3 x 10{sup -5} cm{sup 2} s{sup -1} in 1 M NaOH + 0.01 M NaBH{sub 4} at 25 deg. C in the present study vs. ca. 1.6 x 10{sup -5} cm{sup 2} s{sup -1} in 1 M NaOH + 0.02 M NaBH{sub 4} at 30 deg. C in the literature, as measured by chronoamperometry at a gold microsphere), which is thoroughly discussed. Our measurements using chronoamperometry at a gold microdisk showed that such technique can yield diffusion coefficient values below what expected. The origin of such finding is explained in the frame of the formation of both a film of boron-oxide(s) at the surface of the (static) gold microdisk and the generation of H{sub 2} bubbles at the electrode surface (as a result of the heterogeneous hydrolysis at Au), which alter the access to the electrode surface and thus prevents efficient measurements. Such film formation and H{sub 2} bubbles generation is not so much of an issue for rotating electrodes thanks to the convection of electrolyte which sweeps the electrode surface. In addition, should such film be present, the transit-time determination technique on a RRDE displays the advantage of not being very sensible to its presence: the parameter measured is the time taken by a perturbation generated the

Direct rotating ring-disk measurement of the sodium borohydride diffusion coefficient in sodium hydroxide solutions

International Nuclear Information System (INIS)

Chatenet, M.; Molina-Concha, M.B.; El-Kissi, N.; Parrour, G.; Diard, J.-P.

2009-01-01

This paper presents the experimental determination of the diffusion coefficient of borohydride anion and solution kinematic viscosity for a large panel of NaOH + NaBH 4 electrolytic solutions relevant for use as anolyte in Direct Borohydride Fuel Cells (DBFC). The diffusion coefficients have been measured by the transit-time technique on gold rotating ring-disk electrodes, and verified using other classical techniques reported in the literature, namely the Levich method and Electrochemical Impedance Spectroscopy on a gold RDE, or chronoamperometry at a gold microdisk. The agreement between these methods is generally good. The diffusion coefficients measured from the RRDE technique are however ca. twice larger than those previously reported in the literature (e.g. ca. 3 x 10 -5 cm 2 s -1 in 1 M NaOH + 0.01 M NaBH 4 at 25 deg. C in the present study vs. ca. 1.6 x 10 -5 cm 2 s -1 in 1 M NaOH + 0.02 M NaBH 4 at 30 deg. C in the literature, as measured by chronoamperometry at a gold microsphere), which is thoroughly discussed. Our measurements using chronoamperometry at a gold microdisk showed that such technique can yield diffusion coefficient values below what expected. The origin of such finding is explained in the frame of the formation of both a film of boron-oxide(s) at the surface of the (static) gold microdisk and the generation of H 2 bubbles at the electrode surface (as a result of the heterogeneous hydrolysis at Au), which alter the access to the electrode surface and thus prevents efficient measurements. Such film formation and H 2 bubbles generation is not so much of an issue for rotating electrodes thanks to the convection of electrolyte which sweeps the electrode surface. In addition, should such film be present, the transit-time determination technique on a RRDE displays the advantage of not being very sensible to its presence: the parameter measured is the time taken by a perturbation generated the disk to reach the ring trough a distance several orders

Benefits from flywheel energy storage for area regulation in California - demonstration results : a study for the DOE Energy Storage Systems program.

Energy Technology Data Exchange (ETDEWEB)

Eyer, James M. (Distributed Utility Associates, Livermore, CA)

2009-10-01

This report documents a high-level analysis of the benefit and cost for flywheel energy storage used to provide area regulation for the electricity supply and transmission system in California. Area regulation is an 'ancillary service' needed for a reliable and stable regional electricity grid. The analysis was based on results from a demonstration, in California, of flywheel energy storage developed by Beacon Power Corporation (the system's manufacturer). Demonstrated was flywheel storage systems ability to provide 'rapid-response' regulation. Flywheel storage output can be varied much more rapidly than the output from conventional regulation sources, making flywheels more attractive than conventional regulation resources. The performance of the flywheel storage system demonstrated was generally consistent with requirements for a possible new class of regulation resources - 'rapid-response' energy-storage-based regulation - in California. In short, it was demonstrated that Beacon Power Corporation's flywheel system follows a rapidly changing control signal (the ACE, which changes every four seconds). Based on the results and on expected plant cost and performance, the Beacon Power flywheel storage system has a good chance of being a financially viable regulation resource. Results indicate a benefit/cost ratio of 1.5 to 1.8 using what may be somewhat conservative assumptions. A benefit/cost ratio of one indicates that, based on the financial assumptions used, the investment's financial returns just meet the investors target.

Design of an adaptive finite-time controller for synchronization of two identical/different non-autonomous chaotic flywheel governor systems

International Nuclear Information System (INIS)

Aghababa Mohammad Pourmahmood

2012-01-01

The centrifugal flywheel governor (CFG) is a mechanical device that automatically controls the speed of an engine and avoids the damage caused by sudden change of load torque. It has been shown that this system exhibits very rich and complex dynamics such as chaos. This paper investigates the problem of robust finite-time synchronization of non-autonomous chaotic CFGs. The effects of unknown parameters, model uncertainties and external disturbances are fully taken into account. First, it is assumed that the parameters of both master and slave CFGs have the same value and a suitable adaptive finite-time controller is designed. Second, two CFGs are synchronized with the parameters of different values via a robust adaptive finite-time control approach. Finally, some numerical simulations are used to demonstrate the effectiveness and robustness of the proposed finite-time controllers. (general)

Status of the MEIC ion collider ring design

International Nuclear Information System (INIS)

Morozov, Vasiliy; Derbenev, Yaroslav; Harwood, Leigh; Hutton, Andrew; Lin, Fanglei; Pilat, Fulvia; Zhang, Yuhong; Cai, Yunhai; Nosochkov, Y. M.; Sullivan, Michael; Wang, M.-H.; Wienands, Uli; Gerity, James; Mann, Thomas; McIntyre, Peter; Pogue, Nathaniel; Sattarov, Akhdiyor

2015-09-01

We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated super-conducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

Status of the MEIC ion collider ring design

International Nuclear Information System (INIS)

Morozov, V. S.; Derbenev, Ya. S.; Harwood, L.; Hutton, A.; Lin, F.; Pilat, F.; Zhang, Y.; Cai, Y.; Nosochkov, Y. M.; Sullivan, M.; Wang, M-H; Wienands, U.; Gerity, J.; Mann, T.; McIntyre, P.; Pogue, N. J.; Satttarov, A.

2015-01-01

We present an update on the design of the ion collider ring of the Medium-energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The design is based on the use of super-ferric magnets. It provides the necessary momentum range of 8 to 100 GeV/c for protons and ions, matches the electron collider ring design using PEP-II components, fits readily on the JLab site, offers a straightforward path for a future full-energy upgrade by replacing the magnets with higher-field ones in the same tunnel, and is more cost effective than using presently available current-dominated superconducting magnets. We describe complete ion collider optics including an independently-designed modular detector region.

Robust design of head interconnect for hard disk drive

Science.gov (United States)

Gao, X. K.; Liu, Q. H.; Liu, Z. J.

2005-05-01

Design of head interconnect is one of the important issues for hard disk drives with higher data rate and storage capacity. The impedance of interconnect and electromagnetic coupling influence the quality level of data communication. Thus an insightful study on how the trace configuration affects the impedance and crosstalk is necessary. An effective design approach based on Taguchi's robust design method is employed therefore in an attempt to realize impedance matching and crosstalk minimization with the effects of uncontrollable sources taken into consideration.

Dual-Band Split-Ring Antenna Design for WLAN Applications

OpenAIRE

BAŞARAN, S. Cumhur; ERDEMLİ, Yunus E.

2014-01-01

A dual-band microstrip antenna based on split-ring elements is introduced for WLAN (2.4/5.2 GHz) applications. The proposed split-ring antenna (SRA) has a compact novel design which provides about 2% impedance-bandwidth without a need for additional matching network. Analysis and design of the proposed microstrip antenna is carried out by means of full-wave simulators based on the finite-element method.

SNS accumulator ring design and space charge considerations

International Nuclear Information System (INIS)

Weng, W.T.

1998-01-01

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5micros with average beam power of 1MW. To achieve such purpose, a proton storage ring operated at 60Hz with 1 x 10 14 protons per pulse at 1GeV is required. The Accumulator Ring (AR) receives 1msec long H - beam bunches of 28mA from a 1GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generation and beam collimation etc. is discussed

Collisional dynamics of perturbed particle disks in the solar system. Annual technical progress report

International Nuclear Information System (INIS)

Roberts, W.W.; Stewart, G.R.

1987-03-01

Investigations of the collisional evolution of particulate disks subject to the gravitational perturbation of a more massive particle orbiting within the disk are underway. Both numerical N-body simulations using a novel collision algorithm and analytical kinetic theory are being employed to extend our understanding of perturbed disks in planetary rings and during the formation of the solar system. Particular problems proposed for investigation are: (1) The development and testing of general criteria for a small moonlet to clear a gap and produce observable morphological features in planetary rings; (2) The development of detailed models of collisional damping of the wavy edges observed on the Encke division of Saturn's A ring; and (3) The determination of the extent of runaway growth of the few largest planetesimals during the early stages of planetary accretion

Contribution to design and to integrate a flywheel-based storage system in a test bench for electric vehicles with hybrid source; Contribution a la conception et a l'integration d'un accumulateur cinetique d'energie dans une plate-forme de test pour vehicules electriques a source hybride

Energy Technology Data Exchange (ETDEWEB)

Briat, O.

2002-11-01

This work deals with the design and the integration of a flywheel-based storage system in a test bench for EV with hybrid source. The flywheel used to supply/recover the peak power during acceleration/braking is associated to a battery which supplies the average power. The main goal is to prove the interest of such a sources hybridization for heavy duty EV. First, a simulation tool has been used for EV studies. Models have been validated thanks to on-board vehicle measurements. Then, a EV test bench has been designed on a reduced power scale. The representativeness of this experimental tool has allowed us to validate simulation models. A flywheel module has been integrated and associated to a battery in order to validate the hybridization principle. Experimental results have shown the performances of the battery power limitation and have proved the interest of a systematic regenerative braking on the battery. In these conditions, an increase of the vehicle payload can be expected. (author)

1977 flywheel technology symposium proceedings. [Fifty-two papers

Energy Technology Data Exchange (ETDEWEB)

Chang, G.C.; Stone, R.G. (eds.)

1978-03-01

Fifty-two papers, four paper abstracts, and four brief summaries of panel discussions are presented on flywheel energy storage technology. A separate abstract was prepared for each of 41 papers for inclusion in DOE Energy Research Abstracts (ERA). Eleven papers were processed previously for inclusion in the data base. (PMA)

Flywheel Energy Storage System Suspended by Hybrid Magnetic Bearing

Science.gov (United States)

Owusu-Ansah, Prince; Hu, Yefa; Misbawu, Adam

This work presents a prototype flywheel energy storage system (FESS) suspended by hybrid magnetic bearing (HMB) rotating at a speed of 20000rpm with a maximum storage power capacity of 30W with a maximum tip speed of 300m/s. The design presented is an improvement of most existing FESS, as the design incorporates a unique feature in that the upper and the lower rotor and stator core are tapered which enhances larger thrust and much lower radial force to be exerted on the system. Without any adverse effect being experienced by the model. The work also focuses on the description of developing a prototype FESS suspended by HMB using solid works as a basis of developing in the nearer future a more improved FESS suspended by HMB capable of injecting the ever increasing high energy demand situation in the 21st century and beyond.

Using simulation to aid trial design: Ring-vaccination trials.

Directory of Open Access Journals (Sweden)

Matt David Thomas Hitchings

2017-03-01

Full Text Available The 2014-6 West African Ebola epidemic highlights the need for rigorous, rapid clinical trial methods for vaccines. A challenge for trial design is making sample size calculations based on incidence within the trial, total vaccine effect, and intracluster correlation, when these parameters are uncertain in the presence of indirect effects of vaccination.We present a stochastic, compartmental model for a ring vaccination trial. After identification of an index case, a ring of contacts is recruited and either vaccinated immediately or after 21 days. The primary outcome of the trial is total vaccine effect, counting cases only from a pre-specified window in which the immediate arm is assumed to be fully protected and the delayed arm is not protected. Simulation results are used to calculate necessary sample size and estimated vaccine effect. Under baseline assumptions about vaccine properties, monthly incidence in unvaccinated rings and trial design, a standard sample-size calculation neglecting dynamic effects estimated that 7,100 participants would be needed to achieve 80% power to detect a difference in attack rate between arms, while incorporating dynamic considerations in the model increased the estimate to 8,900. This approach replaces assumptions about parameters at the ring level with assumptions about disease dynamics and vaccine characteristics at the individual level, so within this framework we were able to describe the sensitivity of the trial power and estimated effect to various parameters. We found that both of these quantities are sensitive to properties of the vaccine, to setting-specific parameters over which investigators have little control, and to parameters that are determined by the study design.Incorporating simulation into the trial design process can improve robustness of sample size calculations. For this specific trial design, vaccine effectiveness depends on properties of the ring vaccination design and on the

Disk brake design for cooling improvement using Computational Fluid Dynamics (CFD)

International Nuclear Information System (INIS)

Munisamy, Kannan M; Shafik, Ramel

2013-01-01

The car disk brake design is improved with two different blade designs compared to the baseline blade design. The two designs were simulated in Computational fluid dynamics (CFD) to obtain heat transfer properties such as Nusselt number and Heat transfer coefficient. The heat transfer property is compared against the baseline design. The improved shape has the highest heat transfer performance. The curved design is inferior to baseline design in heat transfer performance.

Disk brake design for cooling improvement using Computational Fluid Dynamics (CFD)

Science.gov (United States)

Munisamy, Kannan M.; Shafik, Ramel

2013-06-01

The car disk brake design is improved with two different blade designs compared to the baseline blade design. The two designs were simulated in Computational fluid dynamics (CFD) to obtain heat transfer properties such as Nusselt number and Heat transfer coefficient. The heat transfer property is compared against the baseline design. The improved shape has the highest heat transfer performance. The curved design is inferior to baseline design in heat transfer performance.

Design and jump phenomenon analysis of an eccentric ring energy harvester

International Nuclear Information System (INIS)

Wang, Yu-Jen; Chen, Chung-De

2013-01-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318–442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers. (paper)

Design and jump phenomenon analysis of an eccentric ring energy harvester

Science.gov (United States)

Wang, Yu-Jen; Chen, Chung-De

2013-10-01

This paper presents the development of a wheel-mounted eccentric ring energy harvester that is driven by centripetal and gravitational forces during wheel rotation. The natural frequency of the eccentric ring matches the wheel rotation frequency at any car speed because its character length is designed equal to the wheel radius. Consequently, the eccentric ring oscillates with a relatively large swing angle at the wheel speed to generate high levels of power. The nonlinear dynamic behavior of the eccentric ring is investigated to ensure that the proposed design produces steady swing angles, especially at high wheel speeds. Herein, the jump phenomenon of the dynamic motion of the eccentric ring is analyzed by using the Duffing equation and the linearization process. The discriminant value obtained from the analysis confirms that no jump phenomenon occurs at all wheel speeds if the eccentric ring is properly designed. In the experiment, the eccentric ring is integrated with magnets and a coil set to generate 318-442 μW at constant wheel speeds between 300 and 500 rpm. This shows that the proposed device is a potential power source for low-power wheel-mounted electronics, such as pressure sensors, accelerometers, and thermometers.

A possible mechanism to detect super-earth formation in protoplanetary disks

Science.gov (United States)

Dong, Ruobing; Chiang, Eugene; Li, Hui; Li, Shengtai

2017-06-01

Using combined gas+dust global hydrodynamics and radiative transfer simulations, we calculate the distribution of gas and sub-mm-sized dust in protoplanetary disks with a super-Earth at tens of AU, and examine observational signatures of such systems in resolved observations. We confirm previous results that in a typical disk with a low viscosity ($\\alpha\\lesssim10^{-4}$), a super-Earth is able to open two gaps at $\\sim$scale-height away around its orbit in $\\sim$mm-sized dust (St$\\sim$0.01), due to differential dust drift in a perturbed gas background. Additional rings and gaps may also be produced under certain conditions. These features, particularly a signature ``double-gap'' feature, can be detected in a Taurus target by ALMA in dust continuum under an angular resolution of $\\sim0\\arcsec.025$ with two hours of integration. The features are robust --- it can survive in a variety of background disk profiles, withstand modest planetary radial migration ($|r/\\dot{r}|\\sim$ a few Myr), and last for thousands of orbits. Multiple ring/gap systems observed by ALMA were typically modeled using multiple (Saturn-to-Jupiter sized) planets. Here, we argue that a single super-Earth in a low viscosity disk could produce multiple rings and gaps as well. By examining the prevalence of such features in nearby disks, upcoming high angular resolution ALMA surveys may infer how common super-Earth formation events are at tens of au.

SNS accumulator ring design and space charge considerations

Energy Technology Data Exchange (ETDEWEB)

Weng, W.T.

1998-08-01

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5 {micro}s with average beam power of 1 MW. To achieve such purpose, a proton storage ring operated at 60 Hz with 1 {times} 10{sup 14} protons per pulse at 1 GeV is required. The Accumulator Ring (AR) receives 1 msec long H{sup {minus}} beam bunches of 28 mA from a 1 GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1 mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generatino and beam collimation etc. is discussed.

SNS ACCUMULATOR RING DESIGN AND SPACE CHARGE CONSIDERATIONS

Energy Technology Data Exchange (ETDEWEB)

WENG,W.T.

1998-05-04

The goal of the proposed Spallation Neutron Source (SNS) is to provide a short pulse proton beam of about 0.5{micro}s with average beam power of 1MW. To achieve such purpose, a proton storage ring operated at 60Hz with 1 x 10{sup 14} protons per pulse at 1GeV is required. The Accumulator Ring (AR) receives 1msec long H{sup {minus}} beam bunches of 28mA from a 1GeV linac. Scope and design performance goals of the AR are presented. About 1,200 turns of charge exchange injection is needed to accumulate 1mA in the ring. After a brief description of the lattice design and machine performance parameters, space charge related issues, such as: tune shifts, stopband corrections, halo generation and beam collimation etc. is discussed.

Planet-driven Spiral Arms in Protoplanetary Disks. II. Implications

Science.gov (United States)

Bae, Jaehan; Zhu, Zhaohuan

2018-06-01

We examine whether various characteristics of planet-driven spiral arms can be used to constrain the masses of unseen planets and their positions within their disks. By carrying out two-dimensional hydrodynamic simulations varying planet mass and disk gas temperature, we find that a larger number of spiral arms form with a smaller planet mass and a lower disk temperature. A planet excites two or more spiral arms interior to its orbit for a range of disk temperatures characterized by the disk aspect ratio 0.04≤slant {(h/r)}p≤slant 0.15, whereas exterior to a planet’s orbit multiple spiral arms can form only in cold disks with {(h/r)}p≲ 0.06. Constraining the planet mass with the pitch angle of spiral arms requires accurate disk temperature measurements that might be challenging even with ALMA. However, the property that the pitch angle of planet-driven spiral arms decreases away from the planet can be a powerful diagnostic to determine whether the planet is located interior or exterior to the observed spirals. The arm-to-arm separations increase as a function of planet mass, consistent with previous studies; however, the exact slope depends on disk temperature as well as the radial location where the arm-to-arm separations are measured. We apply these diagnostics to the spiral arms seen in MWC 758 and Elias 2–27. As shown in Bae et al., planet-driven spiral arms can create concentric rings and gaps, which can produce a more dominant observable signature than spiral arms under certain circumstances. We discuss the observability of planet-driven spiral arms versus rings and gaps.

The short circumference damping ring design for the ILC

CERN Document Server

Korostelev, Maxim S; Kuriki, Masao; Kuroda, Shigeru; Naito, Takashi; Ross, Marc; Urakawa, Junji; Zimmermann, Frank

2005-01-01

The ILC damping ring tentative design is driven by the operational scenario of the main linac, the beam-dynamics demand of producing a stable and high-quality beam, the injection/extraction scheme and the kicker performance. In this paper, a short circumference damping ring design based on TME cells is described. The ring accommodates injection kickers which provide a flat top of 280 nsec and a 60 nsec rise and fall time and very fast strip-line kickers for beam extraction with a 2 nsec rise and fall time for 3-MHz operation. The potential impact of collective effects and the possible degradation of the dynamic aperture by nonlinear-wiggler fields are estimated.

Design for a practical, low-emittance damping ring

International Nuclear Information System (INIS)

Krejcik, P.

1988-01-01

The luminosity requirements for future high-energy linear colliders calls for very low emittances in the two beams. These low emittances can be achieved with damping rings, but, in order to reach the design goal of a factor 10 improvement over present day machines, great care must be taken in their design. This paper emphasizes the need to address simultaneously all of the factors which limit the operational emittance in the ring. Particularly since in standard designs there is a conflict between different design parameters which makes it difficult to extrapolate such designs to very low emittances. The approach chosen here is to resolve such conflicts by separating their design solutions. Wigglers are used predominantly in zero-dispersion regions to achieve the desired damping rate, whereas in the arcs high dispersion insertions are made in regions of zero curvature to allow for easier chromaticity control

Performance testing and economic analysis of a photovoltaic flywheel energy storage and conversion system

Energy Technology Data Exchange (ETDEWEB)

Hay, R. D.; Millner, A. R.; Jarvinen, P. O.

1980-01-01

A subscale prototype of a flywheel energy storage and conversion system for use with photovoltaic power systems of residential and intermediate load-center size has been designed, built and tested by MIT Lincoln Laboratory. System design, including details of such key components as magnetic bearings, motor generator, and power conditioning electronics, is described. Performance results of prototype testing are given and indicate that this system is the equal of or superior to battery-inverter systems for the same application. Results of cost and user-worth analysis show that residential systems are economically feasible in stand-alone and in some utility-interactive applications.

A New Offset Debris Ring around a Nearby Star Observed with the HST/STIS

Science.gov (United States)

Krist, John; Stapelfeldt, Karl; Bryden, Geoffrey

2011-01-01

We are conducting an HST/STIS coronagraphic imaging study of nearby stars that have Spitzer-measured infrared excesses indicating that they are surrounded by debris disks. Around one of the stars we have imaged a debris ring with a sharp inner edge and extending from about 165 AU to 250 AU. The ring center is offset from the star by -8 AU with a visually estimated intrinsic ellipticity of e-0.1 , suggestive of gravitational perturbation of the disk by a planet, like the Fomalhaut disk. Assuming a neutral disk color, the mean surface brightness of V=22.3 mag/square arcsec makes this the second faintest disk yet imaged in scattered light, second to HD 207129.

Filtering and Control of High Speed Motor Current in a Flywheel Energy Storage System

Science.gov (United States)

Kenny, Barbara H.; Santiago, Walter

2004-01-01

The NASA Glenn Research Center has been developing technology to enable the use of high speed flywheel energy storage units in future spacecraft for the last several years. An integral part of the flywheel unit is the three phase motor/generator that is used to accelerate and decelerate the flywheel. The motor/generator voltage is supplied from a pulse width modulated (PWM) inverter operating from a fixed DC voltage supply. The motor current is regulated through a closed loop current control that commands the necessary voltage from the inverter to achieve the desired current. The current regulation loop is the innermost control loop of the overall flywheel system and, as a result, must be fast and accurate over the entire operating speed range (20,000 to 60,000 rpm) of the flywheel. The voltage applied to the motor is a high frequency PWM version of the DC bus voltage that results in the commanded fundamental value plus higher order harmonics. Most of the harmonic content is at the switching frequency and above. The higher order harmonics cause a rapid change in voltage to be applied to the motor that can result in large voltage stresses across the motor windings. In addition, the high frequency content in the motor causes sensor noise in the magnetic bearings that leads to disturbances for the bearing control. To alleviate these problems, a filter is used to present a more sinusoidal voltage to the motor/generator. However, the filter adds additional dynamics and phase lag to the motor system that can interfere with the performance of the current regulator. This paper will discuss the tuning methodology and results for the motor/generator current regulator and the impact of the filter on the control. Results at speeds up to 50,000 rpm are presented.

A RING/DISK/OUTFLOW SYSTEM ASSOCIATED WITH W51 NORTH: A VERY MASSIVE STAR IN THE MAKING

International Nuclear Information System (INIS)

Zapata, Luis A.; Schilke, Peter; Menten, Karl; Ho, Paul T. P.; Rodriguez, Luis F.; Palau, Aina; Garrod, Robin T.

2009-01-01

Sensitive and high angular resolution (∼0.''4) SO 2 [22 2,20 → 22 1,21 ] and SiO[5 → 4] line and 1.3 and 7 mm continuum observations made with the Submillimeter Array (SMA) and the Very Large Array (VLA) toward the young massive cluster W51 IRS2 are presented. We report the presence of a large (of about 3000 AU) and massive (40 M sun ) dusty circumstellar disk and a hot gas molecular ring around a high-mass protostar or a compact small stellar system associated with W51 North. The simultaneous observations of the silicon monoxide molecule, an outflow gas tracer, further revealed a massive (200 M sun ) and collimated (∼14 0 ) outflow nearly perpendicular to the dusty and molecular structures suggesting thus the presence of a single very massive protostar with a bolometric luminosity on the order of 10 5 L sun . A molecular hybrid local thermodynamic equilibrium model of a Keplerian and infalling disk with an inner cavity and a central stellar mass of more than 60 M sun agrees well with the SO 2 [22 2,20 → 22 1,21 ] line observations. Finally, these results suggest that mechanisms, such as mergers of low- and intermediate-mass stars, might not be necessary for forming very massive stars.

A FODO racetrack ring for nuSTORM: design and optimization

Energy Technology Data Exchange (ETDEWEB)

Liu, A.; Bross, A.; Neuffer, D.

2017-07-01

The goal of nuSTORM is to provide well-defined neutrino beams for precise measurements of neutrino cross-sections and oscillations. The nuSTORM decay ring is a compact racetrack storage ring with a circumference of ~ 480 m that incorporates large aperture (60 cm diameter) magnets. There are many challenges in the design. In order to incorporate the Orbit Combination section (OCS), used for injecting the pion beam into the ring, a dispersion suppressor is needed adjacent to the OCS . Concurrently, in order to maximize the number of useful muon decays, strong bending dipoles are needed in the arcs to minimize the arc length. These dipoles create strong chromatic effects, which need to be corrected by nonlinear sextupole elements in the ring. In this paper, a FODO racetrack ring design and its optimization using sextupolar fields via both a Genetic Algorithm (GA) and a Simulated Annealing (SA) algorithm will be discussed.

Development of Disk Rover, wall-climbing robot using permanent magnet disk

International Nuclear Information System (INIS)

Hirose, Shigeo; Tsutsumitake; Hiroshi; Toyama, Ryousei; Kobayashi, Kengo.

1992-01-01

A new type of wall climbing robot, named Disk Rover, using permanent magnet disks are developed. The newly introduced permanent magnet disk is to rotate the magnet disk on the surface of wall with partly contacted posture. It allows to produce high magnetic attraction force compared with conventional permanent wheel which utilizes only a small portion of the magnet installed around the wheel. The optimum design of the magnetic wheel is done by using finit element method and it is shown that the magnetic attraction force vs. weight ratio can be designed about three times higher than conventional type magnet wheel. The developed Disk Rover is 25 kg in weight including controller and battery, about 685 mm in diameter, 239 mm in height and has a pair of permanent magnet disks. It is demonstrated by the experiments that the Disk Rover can move around on the surface of the wall quite smoothly by radio control and has payload of about its own weight. Several considerations are also done in order to surmount bead weld. (author)

Rings Research in the Next Decade

Science.gov (United States)

Burns, J. A.; Tiscareno, M. S.

2009-12-01

The study of planetary ring systems forms a key component of planetary science for several reasons: 1) The evolution and current states of planets and their satellites are affected in many ways by rings, while 2) conversely, properties of planets and moons and other solar system populations are revealed by their effects on rings; 3) highly structured and apparently delicate ring systems may be bellwethers, constraining various theories of the origin and evolution of their entire planetary system; and finally, 4) planetary rings provide an easily observable analogue to other astrophysical disk systems, enabling real “ground truth” results applicable to disks much more remote in space and/or time, including proto-planetary disks, circum-stellar disks, and even galaxies. Significant advances have been made in rings science in the past decade. The highest-priority rings research recommendations of the last Planetary Science Decadal Survey were to operate and extend the Cassini orbiter mission at Saturn; this has been done with tremendous success, accounting for much of the progress made on key science questions, as we will describe. Important progress in understanding the rings of Saturn and other planets has also come from Earth-based observational and theoretical work, again as prioritized by the last Decadal Survey. However, much important work remains to be done. At Saturn, the Cassini Solstice Mission must be brought to a successful completion. Priority should also be placed on sending spacecraft to Neptune and/or Uranus, now unvisited for more than 20 years. At Jupiter and Pluto, opportunities afforded by visiting spacecraft capable of studying rings should be exploited. On Earth, the need for continued research and analysis remains strong, including in-depth analysis of rings data already obtained, numerical and theoretical modeling work, laboratory analysis of materials and processes analogous to those found in the outer solar system, and continued Earth

Cabling design of booster and storage ring construction progress of TPS

International Nuclear Information System (INIS)

Wong, Y.-S.; Liu, K.-B.; Liu, C.-Y.; Wang, B.-S.

2017-01-01

The 2012 Taiwan Photon Source (TPS) cable construction project started after 10 months to complete the cable laying and installation of power supply. The circumference of the booster ring (BR) is 496.8 m, whereas that of the storage ring (SR) is 518.4 m. Beam current is set to 500 mA at 3.3 GeV. The paper on grounding systems discusses the design of the ground wire (< 0.2 Ω) with low impedance, power supply of the accelerator and cabling tray. The flow and size of the ground current are carefully evaluated to avoid grounded current from flowing everywhere, which causes interference problems. In the design of the TPS, special shielding will be established to isolate the effects of electromagnetic interference on the magnet and ground current. Booster ring dipoles are connected by a series of 54-magnet bending dipole; the cable size of its stranded wire measures 250 mm"2, with a total length of 5000 m. Booster ring and storage ring quadrupoles have 150 magnets; the cable size of their stranded wire is 250 mm"2, with a total length of 17000 m. Storage ring dipole consists of 48 magnets; the cable size of its stranded wire is 325 mm"2, with a total length of 6000 m. This study discusses the power supply cabling design of the storage ring and booster ring construction progress of TPS. The sections of this paper are divided into discussions of the construction of the control and instrument area, cabling layout of booster ring and storage ring, as well as the installation and commission machine. This study also discusses the use of a high-impedance meter to determine the effect of cabling insulation and TPS power supply machine on energy transfer to ensure the use of safe and correct magnet.

Design of a quasi-isochronous storage ring for THz light source

International Nuclear Information System (INIS)

Zhu Jiapeng; Xu Hongliang; Feng Guangyao; Lan Jieqin

2012-01-01

A quasi-isochronous storage ring is designed by manipulating lattice parameters to introduce a negative dispersion function to the dispersion section. This quasi-isochronous storage ring is designed for a THz synchrotron radiation source. The simulation of the optics function and beam emittance shows its feasibility, and the tracing result of particles indicates that the designed ring has a good particle dynamic aperture. In addition, a three-dimensional model of the vacuum chamber used for photon radiation in the quasi-isochronous mode is also designed. The eigenmodes of the chamber are simulated, and characteristic parameters such as quality factor, power loss and characteristic impedance are also calculated. The result shows that the vacuum chamber has little effect on the circulating beam. (authors)

Efficient energy transfer and increase of energy density of magnetically charged flywheels

International Nuclear Information System (INIS)

Hinterdorfer, T.

2014-01-01

Flywheel Energy Storage Systems represent an ecologically and economically sustainable technology for decentralized energy storage. Compared to other storage technologies such as e.g. chemical accumulators, they offer longer life cycles without performance degradation over time and usage and need almost no systematic maintenance. Further, they are made of environmentally friendly materials. By means of the driving torque of an electric motor, the flywheel is accelerated and thus electrical energy is transformed to kinetic energy. The stored energy can be transfered back by the load torque of a generator when needed. Modern flywheel energy storage applications use magnetic bearings to minimize selfdischarge. To avoid bearing forces due to rotor eccentricity an unbalance control strategy is used. However, this leads to an off-centered run of the electric machines rotor which in turn generates undesirable forces. A force-compensating operation of the electric machine will minimize the influence on the magnetic bearings in the planned control scheme, thus increasing their efficiency. Different concepts will be developed and compared to each other by means of simulations. Validation of the simulation models is carried out on a specially constructed test setup under defined conditions. In addition, the electrical machine will be integrated into the concept of redundancy of the flywheel. A bearingless operation increases the reliability and enables a safe shutdown of the application in case of malfunction of the magnetic bearings. High strength composite materials are used to achieve high speeds. Based on existing results from past research activities, a disc-shaped rotor is optimized first. To increase material utilization and to maximize energy density a topology optimization is performed. Evolutionary and gradient based optimization algorithms are used. Thereby the unused strength potential of the material is exploited in order to increase the economic efficiency of

Signatures of Young Planets in the Continuum Emission from Protostellar Disks

Science.gov (United States)

Isella, Andrea; Turner, Neal J.

2018-06-01

Many protostellar disks show central cavities, rings, or spiral arms likely caused by low-mass stellar or planetary companions, yet few such features are conclusively tied to bodies embedded in the disks. We note that even small features on the disk surface cast shadows, because the starlight grazes the surface. We therefore focus on accurately computing the disk thickness, which depends on its temperature. We present models with temperatures set by the balance between starlight heating and radiative cooling, which are also in vertical hydrostatic equilibrium. The planet has 20, 100, or 1000 M ⊕, ranging from barely enough to perturb the disk significantly, to clearing a deep tidal gap. The hydrostatic balance strikingly alters the appearance of the model disk. The outer walls of the planet-carved gap puff up under starlight heating, throwing a shadow across the disk beyond. The shadow appears in scattered light as a dark ring that could be mistaken for a gap opened by another more distant planet. The surface brightness contrast between outer wall and shadow for the 1000 M ⊕ planet is an order of magnitude greater than a model neglecting the temperature disturbances. The shadow is so deep that it largely hides the planet-launched outer arm of the spiral wave. Temperature gradients are such that outer low-mass planets undergoing orbital migration will converge within the shadow. Furthermore, the temperature perturbations affect the shape, size, and contrast of features at millimeter and centimeter wavelengths. Thus radiative heating and cooling are key to the appearance of protostellar disks with embedded planets.

Seco-B-Ring Steroidal Dienynes with Aromatic D Ring: Design, Synthesis and Biological Evaluation

Directory of Open Access Journals (Sweden)

Marcin Szybinski

2017-10-01

Full Text Available Continuing our structure-activity studies on the vitamin D analogs with the altered intercyclic seco-B-ring fragment, we designed compounds possessing dienyne system conjugated with the benzene D ring. Analysis of the literature data and the docking experiments seemed to indicate that the target compounds could mimic the ligands with a good affinity to the vitamin D receptor (VDR. Multi-step synthesis of the C/D-ring building block of the tetralone structure was achieved and its enol triflate was coupled with the known A-ring fragments, possessing conjugated enyne moiety, using Sonogashira protocol. The structures of the final products were confirmed by NMR, UV and mass spectroscopy. Their binding affinities for the full-length human VDR were determined and it was established that compound substituted at C-2 with exomethylene group showed significant binding to the receptor. This analog was also able to induce monocytic differentiation of HL-60 cells.

Structure and dynamics of ringed galaxies

International Nuclear Information System (INIS)

Buta, R.J.

1984-01-01

In many spiral and SO galaxies, single or multiple ring structures are visible in the disk. These inner rings (r), outer rings (R), and nuclear rings (nr) were investigated by means of morphology, photometry, and spectroscopy in order to provide basic data on a long neglected phenomenon. The metric properties of each ring are investigated and found to correlate with the structure of the parent galaxy. When properly calibrated, inner rings in barred (SB) systems can be used as geometric extragalactic distance indicators to distances in excess of 100 Mpc. Other statistics are presented that confirm previous indications that the rings have preferred shapes, relative sizes, and orientations with respect to bars. A survey is made of the less homogeneous non-barred (SA) ringed systems, and the causes of the inhomogeneity are isolated. It is shown that rings can be identified in multiple-ring SA systems that are exactly analogous to those in barred spirals

Non-linear development of secular gravitational instability in protoplanetary disks

Science.gov (United States)

Tominaga, Ryosuke T.; Inutsuka, Shu-ichiro; Takahashi, Sanemichi Z.

2018-01-01

We perform non-linear simulation of secular gravitational instability (GI) in protoplanetary disks, which has been proposed as a mechanism of planetesimal and multiple ring formation. Since the timescale of the growth of the secular GI is much longer than the Keplerian rotation period, we develop a new numerical scheme for a long-term calculation utilizing the concept of symplectic integration. With our new scheme, we first investigate the non-linear development of the secular GI in a disk without a pressure gradient in the initial state. We find that the surface density of dust increases by more than a factor of 100 while that of gas does not increase even by a factor of 2, which results in the formation of dust-dominated rings. A line mass of the dust ring tends to be very close to the critical line mass of a self-gravitating isothermal filament. Our results indicate that the non-linear growth of the secular GI provides a powerful mechanism to concentrate the dust. We also find that the dust ring formed via the non-linear growth of the secular GI migrates inward with a low velocity, which is driven by the self-gravity of the ring. We give a semi-analytical expression for the inward migration speed of the dusty ring.

Optics design of Intrabeam Scattering dominated damping rings

CERN Document Server

Antoniou, Fanouria; Papaphilippou, Ioannis

A e+/e- linear collider, the Compact Linear Collider (CLIC) is under design at CERN, aiming to explore the terascale particle physics regime. The collider has been optimized at 3 TeV center of mass energy and targets a luminosity of 1034 cm-2 s-1. In order to achieve this high luminosity, high intensity bunches with ultra low emittances, in all three planes, are required. The generation of ultra low emittance is achieved in the Damping Rings (DR) complex of the collider. The large input beam emittances, especially the ones coming from the positron source, and the requirement of ultra low emittance production in a fast repetition time of 20 ms, imply that the beam damping is done in two stages. Thus, a main-damping ring (DR) and a predamping ring (PDR) are needed, for each particle species. The high bunch brightness gives rise to several collective effects, with Intra-beam scattering (IBS) being the main limitation to the ultra-low emittance. This thesis elaborates the lattice design and non-linear optimizatio...

Ring and peg electrodes for minimally-Invasive and long-term sub-scalp EEG recordings.

Science.gov (United States)

Benovitski, Y B; Lai, A; McGowan, C C; Burns, O; Maxim, V; Nayagam, D A X; Millard, R; Rathbone, G D; le Chevoir, M A; Williams, R A; Grayden, D B; May, C N; Murphy, M; D'Souza, W J; Cook, M J; Williams, C E

2017-09-01

Minimally-invasive approaches are needed for long-term reliable Electroencephalography (EEG) recordings to assist with epilepsy diagnosis, investigation and more naturalistic monitoring. This study compared three methods for long-term implantation of sub-scalp EEG electrodes. Three types of electrodes (disk, ring, and peg) were fabricated from biocompatible materials and implanted under the scalp in five ambulatory ewes for 3months. Disk electrodes were inserted into sub-pericranial pockets. Ring electrodes were tunneled under the scalp. Peg electrodes were inserted into the skull, close to the dura. EEG was continuously monitored wirelessly. High resolution CT imaging, histopathology, and impedance measurements were used to assess the status of the electrodes at the end of the study. EEG amplitude was larger in the peg compared with the disk and ring electrodes (pEEG, mechanical stability, and lower chewing artifact. Whereas, ring electrode arrays tunneled under the scalp enable minimal surgical techniques to be used for implantation and removal. Copyright © 2017 Elsevier B.V. All rights reserved.

Velocity feedback control with a flywheel proof mass actuator

Science.gov (United States)

Kras, Aleksander; Gardonio, Paolo

2017-08-01

This paper presents four new proof mass actuators to be used in velocity feedback control systems for the control of vibrations of machines and flexible structures. A classical proof mass actuator is formed by a coil-magnet linear motor, with either the magnet or the armature-coil proof mass suspended on soft springs. This arrangement produces a net force effect at frequencies above the fundamental resonance frequency of the springs-proof mass system. Thus, it can be used to implement point velocity feedback loops, although the dynamic response and static deflection of the springs-proof mass system poses some stability and control performance limitations. The four proof mass actuators presented in this study include a flywheel element, which is used to augment the inertia effect of the suspended proof mass. The paper shows that the flywheel element modifies both the dynamic response and static deflection of the springs-proof mass system in such a way as the stability and control performance of velocity feedback loops using these actuators are significantly improved.

Direct method of design and stress analysis of rotating disks with temperature gradient

Science.gov (United States)

Manson, S S

1950-01-01

A method is presented for the determination of the contour of disks, typified by those of aircraft gas turbines, to incorporate arbitrary elastic-stress distributions resulting from either centrifugal or combined centrifugal and thermal effects. The specified stress may be radial, tangential, or any combination of the two. Use is made of the finite-difference approach in solving the stress equations, the amount of computation necessary in the evolution of a design being greatly reduced by the judicious selection of point stations by the aid of a design chart. Use of the charts and of a preselected schedule of point stations is also applied to the direct problem of finding the elastic and plastic stress distribution in disks of a given design, thereby effecting a great reduction in the amount of calculation. Illustrative examples are presented to show computational procedures in the determination of a new design and in analyzing an existing design for elastic stress and for stresses resulting from plastic flow.

Contribution to the study of perturbed planetary and protoplanetary disks

International Nuclear Information System (INIS)

Charnoz, Sebastien

2000-01-01

We studied some dynamical and photometric aspects of perturbed planetary and protoplanetary disks. In the first part of this work, using simple numerical models, the thermodynamic evolution of a colliding planetesimal disk perturbed by a giant planet core was studied. As soon as a giant planet embryo (- 15 earth masses) appears, a heat transfer is triggered in the disk, increasing strongly random velocities over a few astronomical units. The long term evolution of this transitory mechanism was investigated as well as its dependence to the perturber's mass. This is a generic mechanism that may have played an important role during the accretion of both terrestrial and giant planet embryos. Consequences concerning the origin of the Asteroid Belt are discussed, as well as the effect of fragmentation that could not been considered, because of numerical limitations. The second part of this work is a photometric study of Saturn's F ring, that is perturbed by its two nearby shepherding satellites. A 300 images data set, obtained at CFH telescope, was used. We put in evidence the presence of some elongated structures in the F ring, which origin is still a matter of debate. By combining our data set with some other spatial telescope images, new accurate orbital solutions for the F ring were derived, yielding a new radius of 140060 Angstroms ±60 km, that is 150 km smaller than the orbit derived in 1980-81. This may be the sign that the F ring suffered an important radial re-structuration during the last twenty years, which possible cause is also discussed. (author) [fr

Energy optimization for a wind DFIG with flywheel energy storage

Energy Technology Data Exchange (ETDEWEB)

Hamzaoui, Ihssen, E-mail: hamzaoui-ihssen2000@yahoo.fr [Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia 16111 Bab-Ezzouar (Algeria); Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Khemis Miliana, Ain Defla (Algeria); Bouchafaa, Farid, E-mail: fbouchafa@gmail.com [Laboratory of Instrumentation, Faculty of Electronics and Computer, University of Sciences and Technology Houari Boumediene, BP 32 El-Alia 16111 Bab-Ezzouar (Algeria)

2016-07-25

The type of distributed generation unit that is the subject of this paper relates to renewable energy sources, especially wind power. The wind generator used is based on a double fed induction Generator (DFIG). The stator of the DFIG is connected directly to the network and the rotor is connected to the network through the power converter with three levels. The objective of this work is to study the association a Flywheel Energy Storage System (FESS) in wind generator. This system is used to improve the quality of electricity provided by wind generator. It is composed of a flywheel; an induction machine (IM) and a power electronic converter. A maximum power tracking technique « Maximum Power Point Tracking » (MPPT) and a strategy for controlling the pitch angle is presented. The model of the complete system is developed in Matlab/Simulink environment / to analyze the results from simulation the integration of wind chain to networks.

Near-Infrared Imaging Polarimetry of Inner Region of GG Tau A Disk

Science.gov (United States)

Yang, Yi; Hashimoto, Jun; Hayashi, Saeko S.; Tamura, Motohide; Mayama, Satoshi; Rafikov, Roman; Akiyama, Eiji; Carson, Joseph C.; Janson, Markus; Kwon, Jungmi;

Stellar Winds and Dust Avalanches in the AU Mic Debris Disk

Energy Technology Data Exchange (ETDEWEB)

Chiang, Eugene; Fung, Jeffrey, E-mail: echiang@astro.berkeley.edu, E-mail: jeffrey.fung@berkeley.edu [Department of Astronomy, University of California at Berkeley, Campbell Hall, Berkeley, CA 94720-3411 (United States)

2017-10-10

We explain the fast-moving, ripple-like features in the edge-on debris disk orbiting the young M dwarf AU Mic. The bright features are clouds of submicron dust repelled by the host star’s wind. The clouds are produced by avalanches: radial outflows of dust that gain exponentially more mass as they shatter background disk particles in collisional chain reactions. The avalanches are triggered from a region a few au across—the “avalanche zone”—located on AU Mic’s primary “birth” ring at a true distance of ∼35 au from the star but at a projected distance more than a factor of 10 smaller: the avalanche zone sits directly along the line of sight to the star, on the side of the ring nearest Earth, launching clouds that disk rotation sends wholly to the southeast, as observed. The avalanche zone marks where the primary ring intersects a secondary ring of debris left by the catastrophic disruption of a progenitor up to Varuna in size, less than tens of thousands of years ago. Only where the rings intersect are particle collisions sufficiently violent to spawn the submicron dust needed to seed the avalanches. We show that this picture works quantitatively, reproducing the masses, sizes, and velocities of the observed escaping clouds. The Lorentz force exerted by the wind’s magnetic field, whose polarity reverses periodically according to the stellar magnetic cycle, promises to explain the observed vertical undulations. The timescale between avalanches, about 10 yr, might be set by time variability of the wind mass loss rate or, more speculatively, by some self-regulating limit cycle.

Development of a High-Fidelity Model for an Electrically Driven Energy Storage Flywheel Suitable for Small Scale Residential Applications

Directory of Open Access Journals (Sweden)

Mustafa E. Amiryar

2018-03-01

Full Text Available Energy storage systems (ESS are key elements that can be used to improve electrical system efficiency by contributing to balance of supply and demand. They provide a means for enhancing the power quality and stability of electrical systems. They can enhance electrical system flexibility by mitigating supply intermittency, which has recently become problematic, due to the increased penetration of renewable generation. Flywheel energy storage systems (FESS are a technology in which there is gathering interest due to a number of advantages offered over other storage solutions. These technical qualities attributed to flywheels include high power density, low environmental impact, long operational life, high round-trip efficiency and high cycle life. Furthermore, when configured in banks, they can store MJ levels of energy without any upper limit. Flywheels configured for grid connected operation are systems comprising of a mechanical part, the flywheel rotor, bearings and casings, and the electric drive part, inclusive of motor-generator (MG and power electronics. This contribution focusses on the modelling and simulation of a high inertia FESS for energy storage applications which has the potential for use in the residential sector in more challenging situations, a subject area in which there are few publications. The type of electrical machine employed is a permanent magnet synchronous motor (PMSM and this, along with the power electronics drive, is simulated in the MATLAB/Simulink environment. A brief description of the flywheel structure and applications are given as a means of providing context for the electrical modelling and simulation reported. The simulated results show that the system run-down losses are 5% per hour, with overall roundtrip efficiency of 88%. The flywheel speed and energy storage pattern comply with the torque variations, whilst the DC-bus voltage remains constant and stable within ±3% of the rated voltage, regardless of

Magnet design for a low-emittance storage ring

International Nuclear Information System (INIS)

Johansson, Martin; Anderberg, Bengt; Lindgren, Lars-Johan

2014-01-01

The magnet design of the MAX IV 3 GeV storage ring replaces the conventional support girder + discrete magnets scheme of previous third-generation light sources with a compact integrated design having several consecutive magnet elements precision-machined out of a common solid iron block. The MAX IV 3 GeV storage ring, currently under construction, pursues the goal of low electron beam emittance by using a multi-bend achromat magnet lattice, which is realised by having several consecutive magnet elements precision-machined out of a common solid iron block, 2.3–3.4 m long. With this magnet design solution, instead of having 1320 individual magnets, the MAX IV 3 GeV storage ring is built up using 140 integrated ‘magnet block’ units, containing all these magnet elements. Major features of this magnet block design are compactness, vibration stability and that the alignment of magnet elements within each unit is given by the mechanical accuracy of the CNC machining rather than individual field measurement and adjustment. This article presents practical engineering details of implementing this magnet design solution, and mechanical + magnetic field measurement results from the magnet production series. At the time of writing (spring 2014), the production series, which is totally outsourced to industry, is roughly half way through, with mechanical/magnetic QA conforming to specifications. It is the conclusion of the authors that the MAX IV magnet block concept, which has sometimes been described as new or innovative, is from a manufacturing point of view simply a collection of known mature production methods and measurement procedures, which can be executed at fixed cost with a low level of risk

On the experimental determination of the efficiency of piezoelectric impact-type energy harvesters using a rotational flywheel

International Nuclear Information System (INIS)

Janphuang, P; Lockhart, R; Briand, D; De Rooij, N F; Henein, S

2013-01-01

This paper demonstrates a novel methodology using a rotational flywheel to determine the energy conversion efficiency of the impact based piezoelectric energy harvesters. The influence of the impact speed and additional proof mass on the efficiency is presented here. In order to convert low frequency mechanical oscillations into usable electrical energy, a piezoelectric harvester is coupled to a rotating gear wheel driven by flywheel. The efficiency is determined from the ratio of the electrical energy generated by the harvester to the mechanical energy dissipated by the flywheel. The experimental results reveal that free vibrations of the harvester after plucking contribute significantly to the efficiency. The efficiency and output energy can be greatly improved by adding a proof mass to the harvester. Under certain conditions, the piezoelectric harvesters have an impact energy conversion efficiency of 1.2%

Structural valve deterioration in a starr-edwards mitral caged-disk valve prosthesis.

Science.gov (United States)

Aoyagi, Shigeaki; Tayama, Kei-Ichiro; Okazaki, Teiji; Shintani, Yusuke; Kono, Michitaka; Wada, Kumiko; Kosuga, Ken-Ichi; Mori, Ryusuke; Tanaka, Hiroyuki

2013-01-01

The durability of the Starr-Edwards (SE) mitral caged-disk valve, model 6520, is not clearly known, and structural valve deterioration in the SE disk valve is very rare. Replacement of the SE mitral disk valve was performed in 7 patients 23-40 years after implantation. Macroscopic examination of the removed disk valves showed no structural abnormalities in 3 patients, in whom the disk valves were removed at valves excised >36 years after implantation in 4 patients. Disk fracture, a longitudinal split in the disk along its circumference at the site of incorporation of the titanium ring, was detected in the valves removed 36 and 40 years after implantation, respectively, and many cracks were also observed on the outflow aspect of the disk removed 40 years after implantation. Disk fracture and localized disk wear were found in the SE mitral disk valves implanted >36 years previously. The present results suggest that SE mitral caged-disk valves implanted >20 years previously should be carefully followed up, and that those implanted >30 years previously should be electively replaced with modern prosthetic valves

Design for ANL 7 GeV storage ring vacuum system

International Nuclear Information System (INIS)

Wehrle, R.B.; Nielsen, R.W.

1988-01-01

The 7-GeV Advanced Photon Source (APS) design includes a storage ring having a 1060-m circumference with the capability of accommodating 34 insertion devices (ID) and their associated photon beam lines. An additional 35 photon lines can be provided from bending magnets. The vacuum system for the storage ring is designed to maintain a beam-on operating pressure of 1n Torr or less to achieve a positron beam lifetime of approximately 20 hours. The vacuum system and it's current developmental status are described

Audit: Automated Disk Investigation Toolkit

Directory of Open Access Journals (Sweden)

Umit Karabiyik

2014-09-01

Full Text Available Software tools designed for disk analysis play a critical role today in forensics investigations. However, these digital forensics tools are often difficult to use, usually task specific, and generally require professionally trained users with IT backgrounds. The relevant tools are also often open source requiring additional technical knowledge and proper configuration. This makes it difficult for investigators without some computer science background to easily conduct the needed disk analysis. In this paper, we present AUDIT, a novel automated disk investigation toolkit that supports investigations conducted by non-expert (in IT and disk technology and expert investigators. Our proof of concept design and implementation of AUDIT intelligently integrates open source tools and guides non-IT professionals while requiring minimal technical knowledge about the disk structures and file systems of the target disk image.

DSTATCOM with Flywheel Energy Storage System for wind energy applications: Control design and simulation

Energy Technology Data Exchange (ETDEWEB)

Suvire, G.O.; Mercado, P.E. [CONICET, Instituto de Energia Electrica, Universidad Nacional de San Juan, San Juan (Argentina)

2010-03-15

In this work, the use of a Distribution Static Synchronous Compensator (DSTATCOM) coupled with a Flywheel Energy Storage System (FESS) is proposed to mitigate problems introduced by wind generation in the electric system. A dynamic model of the DSTATCOM/FESS device is introduced and a multi-level control technique is proposed. This control technique presents one control mode for active power and two control modes for reactive power, power factor correction, and voltage control. Tests of dynamic response of the device are conducted, and performance characteristics are studied taking into consideration variations of power references. Moreover, the behaviour of the device is analyzed when combined with wind generation in the electric system. The results obtained demonstrate a good performance of the model developed and of the control technique proposed as well as a high effectiveness of the device to mitigate problems introduced by wind generation. (author)

Planetary ring systems properties, structures, and evolution

CERN Document Server

Murray, Carl D

2018-01-01

Planetary rings are among the most intriguing structures of our solar system and have fascinated generations of astronomers. Collating emerging knowledge in the field, this volume reviews our current understanding of ring systems with reference to the rings of Saturn, Uranus, Neptune, and more. Written by leading experts, the history of ring research and the basics of ring–particle orbits is followed by a review of the known planetary ring systems. All aspects of ring system science are described in detail, including specific dynamical processes, types of structures, thermal properties and their origins, and investigations using computer simulations and laboratory experiments. The concluding chapters discuss the prospects of future missions to planetary rings, the ways in which ring science informs and is informed by the study of other astrophysical disks, and a perspective on the field's future. Researchers of all levels will benefit from this thorough and engaging presentation.

THE PDS 66 CIRCUMSTELLAR DISK AS SEEN IN POLARIZED LIGHT WITH THE GEMINI PLANET IMAGER

International Nuclear Information System (INIS)

Wolff, Schuyler G.; Greenbaum, Alexandra Z.; Perrin, Marshall; Hines, Dean C.; Millar-Blanchaer, Maxwell A.; Nielsen, Eric L.; Wang, Jason; Dong, Ruobing; Duchêne, Gaspard; Graham, James R.; Kalas, Paul; Cardwell, Andrew; Chilcote, Jeffrey; Draper, Zachary H.; Fitzgerald, Michael P.; Hung, Li-Wei; Goodsell, Stephen J.; Grady, Carol A.; Hartung, Markus; Hibon, Pascale

2016-01-01

We present H- and K-band imaging polarimetry for the PDS 66 circumstellar disk obtained during the commissioning of the Gemini Planet Imager (GPI). Polarization images reveal a clear detection of the disk in to the 0.″12 inner working angle (IWA) in the H band, almost three times closer to the star than the previous Hubble Space Telescope (HST) observations with NICMOS and STIS (0.″35 effective IWA). The centro-symmetric polarization vectors confirm that the bright inner disk detection is due to circumstellar scattered light. A more diffuse disk extends to a bright outer ring centered at 80 AU. We discuss several physical mechanisms capable of producing the observed ring + gap structure. GPI data confirm enhanced scattering on the east side of the disk that is inferred to be nearer to us. We also detect a lateral asymmetry in the south possibly due to shadowing from material within the IWA. This likely corresponds to a temporally variable azimuthal asymmetry observed in HST/STIS coronagraphic imaging

THE PDS 66 CIRCUMSTELLAR DISK AS SEEN IN POLARIZED LIGHT WITH THE GEMINI PLANET IMAGER

Energy Technology Data Exchange (ETDEWEB)

Wolff, Schuyler G.; Greenbaum, Alexandra Z. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Perrin, Marshall; Hines, Dean C. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Millar-Blanchaer, Maxwell A. [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Nielsen, Eric L. [Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States); Wang, Jason; Dong, Ruobing; Duchêne, Gaspard; Graham, James R.; Kalas, Paul [Astronomy Department, University of California, Berkeley, Berkeley, CA 94720 (United States); Cardwell, Andrew [LBT Observatory, University of Arizona, 933 N. Cherry Avenue, Room 552, Tucson, AZ 85721 (United States); Chilcote, Jeffrey [Dunlap Institute for Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada); Draper, Zachary H. [University of Victoria, 3800 Finnerty Road, Victoria, BC V8P 5C2 (Canada); Fitzgerald, Michael P.; Hung, Li-Wei [Department of Physics and Astronomy, University of California, Los Angeles, 430 Portola Plaza, Los Angeles, CA 90095 (United States); Goodsell, Stephen J. [Gemini Observatory, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Hartung, Markus; Hibon, Pascale, E-mail: swolff9@jh.edu [Gemini Observatory, Casilla 603, La Serena (Chile); and others

2016-02-10

We present H- and K-band imaging polarimetry for the PDS 66 circumstellar disk obtained during the commissioning of the Gemini Planet Imager (GPI). Polarization images reveal a clear detection of the disk in to the 0.″12 inner working angle (IWA) in the H band, almost three times closer to the star than the previous Hubble Space Telescope (HST) observations with NICMOS and STIS (0.″35 effective IWA). The centro-symmetric polarization vectors confirm that the bright inner disk detection is due to circumstellar scattered light. A more diffuse disk extends to a bright outer ring centered at 80 AU. We discuss several physical mechanisms capable of producing the observed ring + gap structure. GPI data confirm enhanced scattering on the east side of the disk that is inferred to be nearer to us. We also detect a lateral asymmetry in the south possibly due to shadowing from material within the IWA. This likely corresponds to a temporally variable azimuthal asymmetry observed in HST/STIS coronagraphic imaging.

Dynamical Evolution of Ring-Satellite Systems

Science.gov (United States)

Ohtsuki, Keiji

2005-01-01

The goal of this research was to understand dynamical processes related to the evolution of size distribution of particles in planetary rings and application of theoretical results to explain features in the present rings of giant planets. We studied velocity evolution and accretion rates of ring particles in the Roche zone. We developed a new numerical code for the evolution of ring particle size distribution, which takes into account the above results for particle velocity evolution and accretion rates. We also studied radial diffusion rate of ring particles due to inelastic collisions and gravitational encounters. Many of these results can be also applied to dynamical evolution of a planetesimal disk. Finally, we studied rotation rates of moonlets and particles in planetary rings, which would influence the accretional evolution of these bodies. We describe our key accomplishments during the past three years in more detail in the following.

The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

International Nuclear Information System (INIS)

Podulka, W.J.; Greenly, J.B.; Anderson, D.E.; Glidden, S.C.; Hammer, D.A.; Omelchenko, Yu.A.; Sudan, R.N.

1996-01-01

The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10 17 protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs

The Cornell field-reversed ion ring experiment FIREX: experimental design and first results

Energy Technology Data Exchange (ETDEWEB)

Podulka, W J; Greenly, J B; Anderson, D E; Glidden, S C; Hammer, D A; Omelchenko, Yu A; Sudan, R N [Cornell Univ., Ithaca, NY (United States). Laboratory of Plasma Studies

1997-12-31

The goal of FIREX (Field-reversed Ion Ring EXperiment) is to produce a fully field-reversed ring with 1 MeV protons. Such a ring requires about (2-3) x 10{sup 17} protons, or 30-50 mC of charge. This charge is to be injected as an annular proton beam through a suitable magnetic cusp configuration to produce a compact ring. The critical design issues for the ion beam accelerator are described. First experimental results of ion diode operation indicate that the design is capable of producing the required beam parameters. (author). 4 figs., 4 refs.

IMAGING THE INNER AND OUTER GAPS OF THE PRE-TRANSITIONAL DISK OF HD 169142 AT 7 mm

Energy Technology Data Exchange (ETDEWEB)

Osorio, Mayra; Anglada, Guillem; Macías, Enrique; Gómez, José F.; Mayen-Gijon, Juan M. [Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, E-18008 Granada (Spain); Carrasco-González, Carlos; Rodríguez, Luis F.; D' Alessio, Paola [Centro de Radioastronomía y Astrofísica, UNAM, Apartado Postal 3-72 (Xangari), 58089 Morelia, Michoacán (Mexico); Torrelles, José M. [Institut de Ciències de l' Espai (CSIC)-Institut de Ciències del Cosmos (UB)/IEEC, Martí i Franquès 1, E-08028 Barcelona (Spain); Calvet, Nuria [Department of Astronomy, University of Michigan, 825 Dennison Building, 500 Church Street, Ann Arbor, MI 48109 (United States); Nagel, Erick [Departamento de Astronomía, Universidad de Guanajuato, Guanajuato, Gto 36240 (Mexico); Dent, William R. F. [ALMA SCO, Alonso de Córdova 3107, Vitacura, Santiago (Chile); Quanz, Sascha P.; Reggiani, Maddalena, E-mail: osorio@iaa.es [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)

2014-08-20

We present Very Large Array observations at 7 mm that trace the thermal emission of large dust grains in the HD 169142 protoplanetary disk. Our images show a ring of enhanced emission of radius ∼25-30 AU, whose inner region is devoid of detectable 7 mm emission. We interpret this ring as tracing the rim of an inner cavity or gap, possibly created by a planet or a substellar companion. The ring appears asymmetric, with the western part significantly brighter than the eastern one. This azimuthal asymmetry is reminiscent of the lopsided structures that are expected to be produced as a consequence of trapping of large dust grains. Our observations also reveal an outer annular gap at radii from ∼40 to ∼70 AU. Unlike other sources, the radii of the inner cavity, the ring, and the outer gap observed in the 7 mm images, which trace preferentially the distribution of large (millimeter/centimeter sized) dust grains, coincide with those obtained from a previous near-infrared polarimetric image, which traces scattered light from small (micron-sized) dust grains. We model the broadband spectral energy distribution and the 7 mm images to constrain the disk physical structure. From this modeling we infer the presence of a small (radius ∼0.6 AU) residual disk inside the central cavity, indicating that the HD 169142 disk is a pre-transitional disk. The distribution of dust in three annuli with gaps in between them suggests that the disk in HD 169142 is being disrupted by at least two planets or substellar objects.

Possible origin of Saturn's newly discovered outer ring

International Nuclear Information System (INIS)

Moehlmann, D.

1986-01-01

Within a planetogonic model the self-gravitationally caused formation of pre-planetary and pre-satellite rings from an earlier thin disk is reported. The theoretically derived orbital radii of these rings are compared with the orbital levels in the planetary system and the satellite systems of Jupiter, Saturn and Uranus. From this comparison it is concluded that at the radial position of Saturn's newly discovered outer ring an early pre-satellite ring of more or less evolved satellites could have existed. These satellites should have been disturbed in their evolution by the gravitation of the neighbouring massive satellite Titan. The comparison also may indicate similarities between the asteroidal belt and the newly discovered outer ring of Saturn

Some remarks on the design of HIF current multiplication rings

International Nuclear Information System (INIS)

Reich, K.H.

1983-12-01

The conceptual design of heavy ion fusion drivers has now reached a state, where the overall approach has become fairly clear. One design features an RF linac plus current and beam multiplication rings. The present remarks concern the assignment of multiturn injection, beam storage and bunching to an optimized number of rings and transport lines, as well as some criteria for their designs. The main parameter constraints are discussed, showing how they can be met, although there is little flexibility at the present stage of understanding and technology. A shortened version of this report is scheduled for presentation at the ''INS International Symposium on Heavy Ion Accelerators and Their Application to Inertial Fusion'' Tokyo, January 23-27 1984. (author)

Galaxies and Saturn's rings: Gravitational analogues of nonneutral plasmas

International Nuclear Information System (INIS)

Mark, J.W.K.

1985-01-01

Orbit and collective dynamics in disk galaxies and in Saturn's rings are gravitational analogues of those occurring in nonneutral plasmas. The interesting problems for such ''gravitational plasmas'' are analogous to single-disk studies of transverse dynamics in particle beams. Of particular interest are various orbit-resonances with spiral density and bending waves in these disks which are analogous to electrostatic waves in nonneutral beam plasmas. The background physics, terminology and results of astrophysical investigations in these fields are surveyed in this paper. 53 refs., 19 figs., 1 tab

Design of low energy ring(s)

CERN Document Server

Lachaize, Antoine

During the last two years, several upgrades of the initial baseline scenario were studied with the aim of increasing the average intensity of ion beams in the accelerator chain of the Beta Beam complex. This is the reason why the Rapid Cycling Synchrotron (RCS) specifications were reconsidered many times [1], [2], [3].General considerations on the optical design were presented at the Beta Beam Task Meetings held at CERN and at Saclay in 2005 [4]. More detailed beam optics studies were performed during the next months. Lattices, RF system parameters, multi-turn injection scheme, fast extraction, closed orbit correction and chromaticity correction systems were proposed for different versions of the RCS [5], [6], [7].Finally, the RCS specifications have stabilized in November 2006 after the fourth Beta Beam Task Meeting when it was decided to fix the maximum magnetic rigidity of ion beams to 14.47 T.m (3.5 GeV equivalent proton energy) and to adopt a ring physical radius of 40 m in order to facilitate injectio...

POLARIMETRY WITH THE GEMINI PLANET IMAGER: METHODS, PERFORMANCE AT FIRST LIGHT, AND THE CIRCUMSTELLAR RING AROUND HR 4796A

International Nuclear Information System (INIS)

Perrin, Marshall D.; Duchene, Gaspard; Graham, James R.; Kalas, Paul G.; Millar-Blanchaer, Max; Fitzgerald, Michael P.; Chilcote, Jeffrey; Wiktorowicz, Sloane J.; Dillon, Daren; Gavel, Donald; Macintosh, Bruce; Bauman, Brian; Cardwell, Andrew; Goodsell, Stephen; Hartung, Markus; Hibon, Pascale; De Rosa, Robert J.; Doyon, René; Dunn, Jennifer; Erikson, Darren

2015-01-01

We present the first results from the polarimetry mode of the Gemini Planet Imager (GPI), which uses a new integral field polarimetry architecture to provide high contrast linear polarimetry with minimal systematic biases between the orthogonal polarizations. We describe the design, data reduction methods, and performance of polarimetry with GPI. Point-spread function (PSF) subtraction via differential polarimetry suppresses unpolarized starlight by a factor of over 100, and provides sensitivity to circumstellar dust reaching the photon noise limit for these observations. In the case of the circumstellar disk around HR 4796A, GPI's advanced adaptive optics system reveals the disk clearly even prior to PSF subtraction. In polarized light, the disk is seen all the way in to its semi-minor axis for the first time. The disk exhibits surprisingly strong asymmetry in polarized intensity, with the west side ≳ 9 times brighter than the east side despite the fact that the east side is slightly brighter in total intensity. Based on a synthesis of the total and polarized intensities, we now believe that the west side is closer to us, contrary to most prior interpretations. Forward scattering by relatively large silicate dust particles leads to the strong polarized intensity on the west side, and the ring must be slightly optically thick in order to explain the lower brightness in total intensity there. These findings suggest that the ring is geometrically narrow and dynamically cold, perhaps shepherded by larger bodies in the same manner as Saturn's F ring

Design of delay insensitive circuits using multi-ring structures

DEFF Research Database (Denmark)

Sparsø, Jens; Staunstrup, Jørgen; Dantzer-Sørensen, Michael

1992-01-01

The design and VLSI implementation of a delay insensitive circuit that computes the inner product of two vec·tors is described. The circuit is based on an iterative serial-parallel multiplication algorithm. The design is based on a data flow approach using pipelines and rings that are combined...

Electron ring design for HERA, including spin-matching

International Nuclear Information System (INIS)

Skuja, A.; Hand, L.; Steffen, K.; Barber, D.

1984-01-01

A. Skuja has been working in collaboration with Professor Lou Hand in obtaining an optics for the electron ring at HERA that satisfies the usual constraints of an electron storage ring, but in addition allows longitudinal polarization in the interaction region without depolarizing the electron beam completely. This collaboration effort grew out of their work on a possible electron ring at Fermilab. When this project was degraded in priority at Fermilab, they turned their attention to the HERA project at DESY. The HERA project will have an electron ring of about 30 GeV e - (or e + ) incident on 800 GeV protons. Recently it has been decided that the collisions should be head on (0 0 crossing), although all previous designs had a crossing angle of the 2 beams of 20 mrad. Professors Hand and Skuja implemented a complete program in the last year and a half that could fit the usual Turis parameters as well as the so called 12 spin-matching conditions of Chao and Yukoya for all possible machine elements including solenoids. The program has the possibility of fully coupling vertical and horizontal motion using the usual eigenvalue method

Fermilab Recycler Ring: Technical design report. Revision 1.1

International Nuclear Information System (INIS)

Jackson, G.

1996-07-01

This report describes the technical design of the Fermilab Recycler Ring. The purpose of the Recycler is to augment the luminosity increase anticipated from the implementation of the Fermi III upgrade project, which has as its main component the Fermilab Main Injector construction project. The Recycler is a fixed 8 GeV kinetic energy storage ring. It is located in the Main Injector tunnel directly above the Main Injector beamline, near the ceiling. The construction schedule calls for the installation of the Recycler ring before the installation shutdown of the Main Injector. This aggressive construction schedule is made possible by the exclusive use of permanent magnets in the ring lattice, removing the need for expensive conventional iron/copper magnet construction along with the related power supplies, cooling water system, and electrical safety systems. The location, operating energy, and mode of construction are chosen to minimize operational impacts on both Fermilab's ongoing High Energy Physics program and the Main Injector construction project

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

Energy Technology Data Exchange (ETDEWEB)

Lee, Hansang, E-mail: hslee80@kiu.ac.kr [School of Railway and Electrical Engineering, Kyungil University, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jung, Seungmin [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of); Cho, Yoonsung [Department of Electric and Energy Engineering, Catholic University of Daegu, Hayang-eup, Gyeongsan-si, Gyeongsangbuk-do 712-702 (Korea, Republic of); Yoon, Donghee [Department of New and Renewable Energy, Kyungil University, Hayang-eup, Gyeongsangbuk-do 712-701 (Korea, Republic of); Jang, Gilsoo, E-mail: gjang@korea.ac.kr [School of Electrical Engineering, Korea University, Anam-dong, Seongbuk-gu, Seoul 136-712 (Korea, Republic of)

2013-11-15

Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

International Nuclear Information System (INIS)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-01-01

Highlights: •It is important to develop power and energy management system to save operating cost. •An 100 kWh of SFES is effective to decrease peak power and energy consumption. •Operation cost saving can be achieved using superconducting flywheel energy storage. -- Abstract: This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed

Wobbling The Galactic Disk with Bombardment of Satellite Galaxies

Science.gov (United States)

D'Onghia, Elena

We propose to assess the effect of impacts of large visible satellite galaxies on a disk, as well as the relevance of the continuing bombardment of the Galactic disk by dark matter clumps as predicted by the current cosmological framework that can wobble the disk, heating it and eventually exciting ragged spiral structures. In particular, we make detailed predictions for observable features such as spiral arms, rings and their associated stars in galactic disks and relate them to the physical processes that drive their formation and evolution in our Milky Way galaxy and nearby spirals. To do this, we will combine analytic methods and numerical simulations that allow us to calculate observables, which we will compare to present and forthcoming observations. Our methodology utilizes a combination of state of the art hydrodynamic simulations of galaxy evolution and multi- wavelength radiative transfer simulations. Our primary goals are: (1) To identify the physical processes that are responsible for spiral structure formation observed in our Milky Way and nearby disk galaxies, from the flocculent to grand- designed spiral galaxies and to provide observable signatures to be compared with data on nearby galaxies combining maps of 24 micron emission (Spitzer) and cold gas, CO (Heracles) and HI (THINGS). (2) To explore different morphologies of spiral galaxies: from the multi-armed galaxies to the Milky Way sized galaxies with few arms. (3) For a Milky Way disk we will assess the effect of impacts of substructures passing through the disk to origin the asymmetry in the number density of stars recently discovered from SDSS and SEGUE data and confirmed from RAVE data. We will also investigate the disk heating in the vertical plane due to the formation of vertical oscillations that are produced by the impact and migration of stars in the disk as consequence of the heating as compared to the classical stellar migration mechanism. (4) We will measure the spiral pattern speed

Revealing asymmetries in the HD 181327 debris disk: A recent massive collision or interstellar medium warping

Energy Technology Data Exchange (ETDEWEB)

Stark, Christopher C.; Kuchner, Marc J. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory, Code 667, Greenbelt, MD 20771 (United States); Schneider, Glenn [Steward Observatory, The University of Arizona, Tucson, AZ 85721 (United States); Weinberger, Alycia J. [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road NW, Washington, DC 20015 (United States); Debes, John H. [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Grady, Carol A. [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Jang-Condell, Hannah, E-mail: christopher.c.stark@nasa.gov [Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071 (United States)

2014-07-01

New multi-roll coronagraphic images of the HD 181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain. We detect large scale asymmetries in the disk, consistent with either the recent catastrophic disruption of a body with mass >1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.

Revealing Asymmetries in the HD 181327 Debris Disk: A Recent Massive Collision or Interstellar Medium Warping

Science.gov (United States)

Stark, Christopher C.; Schneider, Glenn; Weinberger, Alycia J.; Debes, John H.; Grady, Carol A.; Jang-Condell, Hannah; Kuchner, Marc J.

2014-07-01

New multi-roll coronagraphic images of the HD 181327 debris disk obtained using the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveal the debris ring in its entirety at high signal-to-noise ratio and unprecedented spatial resolution. We present and apply a new multi-roll image processing routine to identify and further remove quasi-static point-spread function-subtraction residuals and quantify systematic uncertainties. We also use a new iterative image deprojection technique to constrain the true disk geometry and aggressively remove any surface brightness asymmetries that can be explained without invoking dust density enhancements/deficits. The measured empirical scattering phase function for the disk is more forward scattering than previously thought and is not well-fit by a Henyey-Greenstein function. The empirical scattering phase function varies with stellocentric distance, consistent with the expected radiation pressured-induced size segregation exterior to the belt. Within the belt, the empirical scattering phase function contradicts unperturbed debris ring models, suggesting the presence of an unseen planet. The radial profile of the flux density is degenerate with a radially varying scattering phase function; therefore estimates of the ring's true width and edge slope may be highly uncertain. We detect large scale asymmetries in the disk, consistent with either the recent catastrophic disruption of a body with mass >1% the mass of Pluto, or disk warping due to strong interactions with the interstellar medium.

Fast disk array for image storage

Science.gov (United States)

Feng, Dan; Zhu, Zhichun; Jin, Hai; Zhang, Jiangling

1997-01-01

A fast disk array is designed for the large continuous image storage. It includes a high speed data architecture and the technology of data striping and organization on the disk array. The high speed data path which is constructed by two dual port RAM and some control circuit is configured to transfer data between a host system and a plurality of disk drives. The bandwidth can be more than 100 MB/s if the data path based on PCI (peripheral component interconnect). The organization of data stored on the disk array is similar to RAID 4. Data are striped on a plurality of disk, and each striping unit is equal to a track. I/O instructions are performed in parallel on the disk drives. An independent disk is used to store the parity information in the fast disk array architecture. By placing the parity generation circuit directly on the SCSI (or SCSI 2) bus, the parity information can be generated on the fly. It will affect little on the data writing in parallel on the other disks. The fast disk array architecture designed in the paper can meet the demands of the image storage.

Ultrasound diagnosis of cervical spine intervertebral disks hernia

International Nuclear Information System (INIS)

Abdullajev, R.Ya.; Gapchenko, V.V.; Ponomarenko, S.O.

2006-01-01

Forty-seven patients underwent ultrasonography followed by radiography, computed tomography (CT) or MRI. Due to its accessibility and safety for the patient ultrasonography allows not only to assess the presence and degree of the degenerative changes in the pulp ous nucleus and disk fibrous ring but also allows to observe the process dynamically

Probing the Cold Dust Emission in the AB Aur Disk: A Dust Trap in a Decaying Vortex?

Science.gov (United States)

Fuente, Asunción; Baruteau, Clément; Neri, Roberto; Carmona, Andrés; Agúndez, Marcelino; Goicoechea, Javier R; Bachiller, Rafael; Cernicharo, José; Berné, Olivier

2017-09-01

One serious challenge for planet formation is the rapid inward drift of pebble-sized dust particles in protoplanetary disks. Dust trapping at local maxima in the disk gas pressure has received much theoretical attention but still lacks observational support. The cold dust emission in the AB Aur disk forms an asymmetric ring at a radius of about 120 au, which is suggestive of dust trapping in a gas vortex. We present high spatial resolution (0".58×0".78 ≈ 80×110 au) NOEMA observations of the 1.12 mm and 2.22 mm dust continuum emission from the AB Aur disk. Significant azimuthal variations of the flux ratio at both wavelengths indicate a size segregation of the large dust particles along the ring. Our continuum images also show that the intensity variations along the ring are smaller at 2.22 mm than at 1.12 mm, contrary to what dust trapping models with a gas vortex have predicted. Our two-fluid (gas+dust) hydrodynamical simulations demonstrate that this feature is well explained if the gas vortex has started to decay due to turbulent diffusion, and dust particles are thus losing the azimuthal trapping on different timescales depending on their size. The comparison between our observations and simulations allows us to constrain the size distribution and the total mass of solid particles in the ring, which we find to be of the order of 30 Earth masses, enough to form future rocky planets.

Probing the Cold Dust Emission in the AB Aur Disk: A Dust Trap in a Decaying Vortex?

Energy Technology Data Exchange (ETDEWEB)

Fuente, Asunción; Bachiller, Rafael [Observatorio Astronómico Nacional (OAN, IGN), Apdo 112, E-28803 Alcalá de Henares (Spain); Baruteau, Clément; Carmona, Andrés; Berné, Olivier [IRAP, Université de Toulouse, CNRS, UPS, Toulouse (France); Neri, Roberto [Institut de Radioastronomie Millimétrique (IRAM), 300 rue de la Piscine, F-38406 Saint Martin d’Hères (France); Agúndez, Marcelino; Goicoechea, Javier R.; Cernicharo, José, E-mail: a.fuente@oan.es [Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC), E-28049 Cantoblanco, Madrid (Spain)

2017-09-01

One serious challenge for planet formation is the rapid inward drift of pebble-sized dust particles in protoplanetary disks. Dust trapping at local maxima in the disk gas pressure has received much theoretical attention but still lacks observational support. The cold dust emission in the AB Aur disk forms an asymmetric ring at a radius of about 120 au, which is suggestive of dust trapping in a gas vortex. We present high spatial resolution (0.″58 × 0.″78 ≈ 80 × 110 au) NOEMA observations of the 1.12 mm and 2.22 mm dust continuum emission from the AB Aur disk. Significant azimuthal variations of the flux ratio at both wavelengths indicate a size segregation of the large dust particles along the ring. Our continuum images also show that the intensity variations along the ring are smaller at 2.22 mm than at 1.12 mm, contrary to what dust trapping models with a gas vortex have predicted. Our two-fluid (gas+dust) hydrodynamical simulations demonstrate that this feature is well explained if the gas vortex has started to decay due to turbulent diffusion, and dust particles are thus losing the azimuthal trapping on different timescales depending on their size. The comparison between our observations and simulations allows us to constrain the size distribution and the total mass of solid particles in the ring, which we find to be of the order of 30 Earth masses, enough to form future rocky planets.

Planetary Rings

Science.gov (United States)

Nicholson, P. D.

2001-11-01

A revolution in the studies in planetary rings studies occurred in the period 1977--1981, with the serendipitous discovery of the narrow, dark rings of Uranus, the first Voyager images of the tenuous jovian ring system, and the many spectacular images returned during the twin Voyager flybys of Saturn. In subsequent years, ground-based stellar occultations, HST observations, and the Voyager flybys of Uranus (1986) and Neptune (1989), as well as a handful of Galileo images, provided much additional information. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings and their retinues of attendant satellites. Among the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the context of galactic disks), electromagnetic resonances, spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to collective instabilities, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto parent bodies. Perhaps most puzzling is Saturn's multi-stranded, clumpy F ring, which continues to defy a simple explanation 20 years after it was first glimpsed in grainy images taken by Pioneer 11. Voyager and HST images reveal a complex, probably chaotic, dynamical interaction between unseen parent bodies within this ring and its two shepherd satellites, Pandora and Prometheus. The work described here reflects contributions by Joe Burns, Jeff Cuzzi, Luke Dones, Dick French, Peter Goldreich, Colleen McGhee, Carolyn Porco, Mark Showalter, and Bruno Sicardy, as well as those of the author. This research has been supported by NASA's Planetary Geology and Geophysics program and the

Conceptual design of a linac-stretcher ring to obtain a 2-gev continuous electron beam

International Nuclear Information System (INIS)

Cho, Y.; Holt, R.J.; Jackson, H.E.; Khoe, T.K.; Mavrogenes, G.S.

1981-01-01

In order to obtain a high duty factor, >100 /mu/A 2-Gev electron beam, a linac-stretcher ring system was designed. The system is an attractive option because it draws heavily on the existing accelerator technology. The linac-stretcher ring consists of a 2-Gev SLAC-type pulsed linac which injects into a storage ring. In between linac pulses, the stored electron beam is to extract resonantly. This design differs from those discussed recently in several important respects. The storage ring includes an rf system whose purpose is to control the beam orbit and rate of extraction from the ring. With an rf system in the ring, the injection scheme consists of a few turns of synchronous transfers of beam between the linac and storage ring. 4 refs

Design parameters for a small storage ring optimized as an x-ray lithography source

International Nuclear Information System (INIS)

Grobman, W.D.

1983-01-01

This paper examines the design parameters for a ''compact storage ring'' which is matched well to x-ray lithographic requirements, but is as small as possible. This calculation uses a model of a lithographic system which obtains its input parameters from a technology of mask, resist and beam line based on the IBM program at the Brookhaven National Laboratory vacuum ultraviolet electron storage ring. Based on this lithographic system, we model exposure throughput as a function of storage ring parameters to understand which storage ring designs provide adequate but not excessive soft x-ray flux in the lithographically important region. Our scan of storage ring sources will cover a wide range of energies and magnetic fields, to permit consideration of superconducting as well as more standard strong- or weak-focusing designs. Furthermore, we will show that the results of the calculations presented here can be scaled in a simple way to cover a wide range of x-ray lithography system assumptions

Conceptual design of elliptical cavities for intensity and position sensitive beam measurements in storage rings

International Nuclear Information System (INIS)

Sanjari, M S; Chen, X; Hülsmann, P; Litvinov, Yu A; Nolden, F; Piotrowski, J; Steck, M; Stöhlker, Th

2015-01-01

Position sensitive beam monitors are indispensable for the beam diagnostics in storage rings. Apart from their applications in the measurements of beam parameters, they can be used in non-destructive in-ring decay studies of radioactive ion beams as well as enhancing precision in the isochronous mass measurement technique. In this work, we introduce a novel approach based on cavities with elliptical cross-section, in order to compensate the limitations of known designs for the application in ion storage rings. The design is aimed primarily for future heavy ion storage rings of the FAIR project. The conceptual design is discussed together with simulation results. (paper)

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1975-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting, This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (Auth.)

Preparation of thin actinide metal disks using a multiple disk casting technique

International Nuclear Information System (INIS)

Conner, W.V.

1976-01-01

A casting technique has been developed for preparing multiple actinide metal disks which have a minimum thickness of 0.006 inch. This technique was based on an injection casting procedure which utilizes the weight of a tantalum metal rod to force the molten metal into the mold cavity. Using the proper mold design and casting parameters, it has been possible to prepare ten 1/2 inch diameter neptunium or plutonium metal disks in a single casting. This casting technique is capable of producing disks which are very uniform. The average thickness of the disks from a typical casting will vary no more than 0.001 inch and the variation in the thickness of the individual disks will range from 0.0001 to 0.0005 inch. (author)

Design, modeling and testing of integrated ring extractor for high resolution electrohydrodynamic (EHD) 3D printing

International Nuclear Information System (INIS)

Han, Yiwei; Dong, Jingyan

2017-01-01

This paper presents an integrated ring extractor design in electrohydrodynamic (EHD) printing, which can overcome the standoff height limitation in the EHD printing process, and improve printing capability for 3D structures. Standoff height in the EHD printing will affect printing processes and limit the height of the printed structure when the ground electrode is placed under the substrate. In this work, we designed and integrated a ring electrode with the printing nozzle to achieve a self-working printer head, which can start and maintain the printing process without the involvement of the substrate. We applied a FEA method to model the electric field potential distribution and strength to direct the ring extractor design, which provides a similar printing capability with the system using substrate as the ground electrode. We verified the ring electrode design by experiments, and those results from the experiments demonstrated a good match with results from the FEA simulation. We have characterized the printing processes using the integrated ring extractor, and successfully applied this newly designed ring extractor to print polycaprolactone (PCL) 3D structures. (paper)

Storage ring design of the 8 GeV synchrotron radiation facility (SPring-8)

International Nuclear Information System (INIS)

Hara, M.; Bc, S.H.; Motonaga, S.

1990-01-01

In Japan, RIKEN (Institute of Physical and Chemical Research) and JAERI (Japan Atomic Energy Research Institute) have organized a joint design team and started a design study for an 8 GeV synchrotron radiation X-ray source. This paper outlines the status of the design study for the 8 GeV highly brilliant synchrotron radiation X-ray source ring named Super Photon Ring (SPring-8). The facility consists of a main storage ring, a full-energy injector booster synchrotron and a pre-injector 1 GeV linac. The injector linac and synchrotron are laid outside the storage ring because to permit the use of the linac and synchrotron not only as an injector but also as an electron or positron beam source. The purpose of the facility is to provide stable photon beams with high brilliance in the X-ray region. The energy of the stored electrons (positrons) is fixed at 8 GeV to fulfill the required condition using conventional type insertion devices. (N.K.)

Fusion component design for the moving-ring field-reversed mirror reactor

International Nuclear Information System (INIS)

Carlson, G.A.

1981-01-01

This partial report on the reactor design contains sections on the following: (1) burner section magnet system design, (2) plasma ring energy recovery, (3) vacuum system, (4) cryogenic system, (5) tritium flows and inventories, and (6) reactor design and layout

Dynamical Evolution of the Debris Disk after a Satellite Catastrophic Disruption around Saturn

International Nuclear Information System (INIS)

Hyodo, Ryuki; Charnoz, Sébastien

2017-01-01

The hypothesis of the recent origin of Saturn’s rings and its midsized moons is actively debated. It was suggested that a proto-Rhea and a proto-Dione might have collided recently, giving birth to the modern system of midsized moons. It has also been suggested that the rapid viscous spreading of the debris may have implanted mass inside Saturn’s Roche limit, giving birth to its modern ring system. However, this scenario has only been investigated in a very simplified way for the moment. This paper investigates it in detail to assess its plausibility by using N -body simulations and analytical arguments. When the debris disk is dominated by its largest remnant, N -body simulations show that the system quickly reaccretes into a single satellite without significant spreading. On the other hand, if the disk is composed of small particles, analytical arguments suggest that the disk experiences dynamical evolutions in three steps. The disk starts significantly excited after the impact and collisional damping dominates over the viscous spreading. After the system flattens, the system can become gravitationally unstable when particles are smaller than ∼100 m. However, the particles grow faster than spreading. Then, the system becomes gravitationally stable again and accretion continues at a slower pace, but spreading is inhibited. Therefore, the debris is expected to reaccrete into several large bodies. In conclusion, our results show that such a scenario may not form today’s ring system. In contrast, our results suggest that today’s midsized moons are likely reaccreted from such a catastrophic event.

Dynamical Evolution of the Debris Disk after a Satellite Catastrophic Disruption around Saturn

Energy Technology Data Exchange (ETDEWEB)

Hyodo, Ryuki [Earth-Life Science Institute/Tokyo Institute of Technology, 2-12-1 Tokyo (Japan); Charnoz, Sébastien [Institut de Physique du Globe, 75005 Paris (France)

2017-07-01

The hypothesis of the recent origin of Saturn’s rings and its midsized moons is actively debated. It was suggested that a proto-Rhea and a proto-Dione might have collided recently, giving birth to the modern system of midsized moons. It has also been suggested that the rapid viscous spreading of the debris may have implanted mass inside Saturn’s Roche limit, giving birth to its modern ring system. However, this scenario has only been investigated in a very simplified way for the moment. This paper investigates it in detail to assess its plausibility by using N -body simulations and analytical arguments. When the debris disk is dominated by its largest remnant, N -body simulations show that the system quickly reaccretes into a single satellite without significant spreading. On the other hand, if the disk is composed of small particles, analytical arguments suggest that the disk experiences dynamical evolutions in three steps. The disk starts significantly excited after the impact and collisional damping dominates over the viscous spreading. After the system flattens, the system can become gravitationally unstable when particles are smaller than ∼100 m. However, the particles grow faster than spreading. Then, the system becomes gravitationally stable again and accretion continues at a slower pace, but spreading is inhibited. Therefore, the debris is expected to reaccrete into several large bodies. In conclusion, our results show that such a scenario may not form today’s ring system. In contrast, our results suggest that today’s midsized moons are likely reaccreted from such a catastrophic event.

Ring wormholes via duality rotations

Directory of Open Access Journals (Sweden)

Gary W. Gibbons

2016-09-01

Full Text Available We apply duality rotations and complex transformations to the Schwarzschild metric to obtain wormhole geometries with two asymptotically flat regions connected by a throat. In the simplest case these are the well-known wormholes supported by phantom scalar field. Further duality rotations remove the scalar field to yield less well known vacuum metrics of the oblate Zipoy–Voorhees–Weyl class, which describe ring wormholes. The ring encircles the wormhole throat and can have any radius, whereas its tension is always negative and should be less than −c4/4G. If the tension reaches the maximal value, the geometry becomes exactly flat, but the topology remains non-trivial and corresponds to two copies of Minkowski space glued together along the disk encircled by the ring. The geodesics are straight lines, and those which traverse the ring get to the other universe. The ring therefore literally produces a hole in space. Such wormholes could perhaps be created by negative energies concentrated in toroidal volumes, for example by vacuum fluctuations.

SXLS storage ring design

International Nuclear Information System (INIS)

Anon.

1991-01-01

X-ray lithography has emerged as a strong candidate to meet the demands of ever finer linewidths on integrated circuits, particularly for linewidths less than .25 microns. Proximity printing X-ray lithography makes use of soft X-rays to shadow print an image of a mask onto a semiconductor wafer to produce integrated circuits. To generate the required X-rays in sufficient quantities to make commercial production viable, electron storage rings have been proposed as the soft X-ray sources. Existing storage rings have been used to do the initial development work and the success of these efforts has led the lithographers to request that new rings be constructed that are dedicated to X-ray lithography. As a result of a series of workshops held at BNL [10.3] which were attended by both semiconductor and accelerator scientists, the following set of zeroth order specifications' on the light and electron beam of a storage ring for X-ray lithography were developed: critical wavelength of light: λ c = 6 to 10 angstroms, white light power: P = 0.25 to 2.5 watts/mrad, horizontal collection angle per port: θ = 10 to 50 mrad, electron beam sizes: σ x ∼ σ y y ' < 1 mrad

Fundamental Design Principles of Linear Collider Damping Rings, with an Application to CLIC

CERN Document Server

Potier, J P

2000-01-01

Damping Rings for Linear Colliders have to produce very small normalised emittances at a high repetition rate. A previous paper presented analytical expressions for the equilibrium emittance of an arc cell as a function of the deflection angle per dipole. In addition, an expression for the lattice parameters providing the minimum emittance, and a strategy to stay close to this, were proposed. This analytical approach is extended to the detailed design of Damping Rings, taking into account the straight sections and the damping wigglers. Complete rings, including wiggler and injection insections, were modelled with the MAD [1] program, and their performance was found to be in good agreement with the analytical calculation. With such an approach it is shown that a Damping Ring corresponding to the Compact Linear Collider (CLIC) parameters at 0.5 and 1 TeV centre-of-mass energy, and tunable for two different sets of emittance and injection repetition rate, can be designed using the same ring layout.

[right] - DUST RING AROUND STAR OFFERS NEW CLUES INTO PLANET FORMATION

Science.gov (United States)

2002-01-01

A NASA Hubble Space Telescope false-color near infrared image of a novel type of structure seen in space - a dust ring around a star. Superficially resembling Saturn's rings -- but on a vastly larger scale -- the 'hula-hoop' around the star called HR 4796A offers new clues into the possible presence of young planets. The near-infrared light reflecting off the dust ring is about 1,000 times fainter than the illuminating central star. Astronomers used a coronagraphic camera on Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS), specifically designed to enable observations of very faint and low surface brightness objects in the close proximity to bright stars. Even with the coronagraph, the glare from HR 4796A overwhelms the much-fainter ring at distances less than about 4 billion miles (inside the blacked-out circle, centered on the star). Hubble's crisp view was able to resolve the ring, seen at lower resolution at longer wavelengths, in ground-based thermal infrared images, as a disk with some degree of central clearing. The ring has an angular radius of 1.05 arc seconds, equivalent to the apparent size of a dime seen more than 4 miles away. Unlike the extensive disks of dust seen around other young stars, the HR 4796A dust ring, 6.5 billion miles from the star, is tightly confined within a relatively narrow zone less than 17 Astronomical Units wide. An Astronomical Unit is the distance from the Earth to the Sun). For comparison, the ring width is approximately equal to the distance separating the orbits of Mars and Uranus in our own Solar System. All dust rings, whether around stars or planets, can only stay intact by some mechanism confining the dust, likely the gravitational tug of unseen planets. The image was taken on March 15, 1998, centered at a near infrared wavelength of 1.1 microns. The false-color corresponds to the ring's brightness (yellow is bright, purple is faint). The ring, which is undoubtedly circular, appears elliptical since

A superconducting thrust-bearing system for an energy storage flywheel

Energy Technology Data Exchange (ETDEWEB)

Coombs, T.A.; Cansiz, A.; Campbell, A.M. [IRC in Superconductivity, Cambridge (United Kingdom)

2002-05-01

We have constructed a bearing system for an energy storage flywheel. This bearing system uses a combination of permanent magnets and superconductors in an arrangement commonly termed as an Evershed bearing. In an Evershed system there are in fact two bearings which act in concert. In our system we have one bearing constructed entirely out of permanent magnets acting in attraction. This system bears the weight of the flywheel (43.6 kg) but would not, on its own, be stable. Stability is provided by a superconducting bearing which is formed by the interaction between the magnetic field of a permanent magnet sited on the rotor and superconductors on the stator. This overall arrangement is stable over a range of levitation heights and has been tested at rotation speeds of up to around 12 Hz (the maximum speed is dictated by the drive system not the bearing system). There is a sharp resonance peaking at between 2 and 3 Hz and spin down tests indicate that the equivalent coefficient of friction is of the order of 10{sup -5}. The rate of change of velocity is, however, not constant so the drag is clearly not solely frictional. The position of the resonance is dictated by the stiffness of the bearing relative to the mass of the flywheel but the amplitude of the resonance is dictated by the variation in magnitude of the magnetic field of the permanent magnets. Large magnets are (at present) fabricated in sections and this leads to a highly inhomogeneous field. The field has been smoothed by using a combination of iron which acts passively and copper which provides magnetic shielding due to the generation of eddy currents and therefore acts as an 'active' component. Calculations based on the spin down tests indicate that the resultant variation in field is of the order of 3% and measurements are being carried out to confirm this. (author)

Design, Prototyping, and Analysis of a Novel Modular Permanent Magnet Transverse Flux Disk Generator

DEFF Research Database (Denmark)

Hosseini, Seyedmohsen; Moghani, Javad Shokrollahi; Ershad, Nima Farrokhzad

2011-01-01

by circular flat shaped Nd-Fe-B permanent magnets. First, a typical low power generator is designed, and then partially optimized. The optimization objective is to find an inner radius which maximizes the power factor, the output power to mass ratio and the efficiency. The generator equivalent circuit......This paper presents the design, prototyping, and analysis of a novel modular transverse flux permanent magnet disk generator. The disk-shaped structure simplifies the construction procedure by using laminated steel sheets. To reduce output harmonics, the excitation of the generator is done...... parameters are computed by three dimensional finite element analyses. The simulation results show that the power factor of the proposed structure is considerably greater than the power factor previously reported for other transverse flux permanent magnet generator structures. To verify the simulation results...

Passive scalar transport mediated by laminar vortex rings

Energy Technology Data Exchange (ETDEWEB)

Hernández, R H; Rodríguez, G, E-mail: rohernan@ing.uchile.cl [LEAF-NL, Depto. Ingeniería Civil Mecánica, Universidad de Chile, Casilla 2777, Santiago (Chile)

2017-04-15

Numerical simulations were used to study the dynamics of a passive conserved scalar quantity entrained by a self-propelling viscous vortex ring. The transport and mixing process of the passive scalar variable were studied considering two initial scalar distributions: (i) The scalar substance was introduced into the ring during its formation, further focusing in the shedding into the wake of the ring; (ii) A disk-like scalar layer was placed in the ring’s path where the entrainment of the scalar substance into the ring bubble was studied as a function of the ring strength. In both cases, the scalar concentration inside the vortex bubble exhibits a steady decay with time. In the second case, it was shown that the entrained scalar mass grows with both the Reynolds number of the ring and the thickness of the scalar layer in the propagation direction. The ring can be viewed as a mechanism for scalar transportation along important distances. (paper)

The design of the Spectrometer Ring at the HIAF

Science.gov (United States)

Wu, B.; Yang, J. C.; Xia, J. W.; Yan, X. L.; Hu, X. J.; Mao, L. J.; Sheng, L. N.; Wu, J. X.; Yin, D. Y.; Chai, W. P.; Shen, G. D.; Ge, W. W.; Wang, G.; Zhao, H.; Ruan, S.; Ma, X. W.; Wang, M.; Litvinov, S.; Wen, W. Q.; Chen, X. C.; Chen, R. J.; Tang, M. T.; Wu, W.; Luo, C.; Zhao, T. C.; Shi, C. F.; Fu, X.; Liu, J.; Liang, L.

2018-02-01

The Spectrometer Ring (SRing) is an essential part of the High Intensity heavy-ion Accelerator Facility project (HIAF) in China. It is designed as a multi-functional experimental storage ring, which will be able to operate in three ion optical operation modes. The SRing will be used as a time-of-flight mass spectrometer for short-lived, especially neutron-rich nuclei. It will also be used to collect and cool Rare Isotope Beams (RIBs) or highly-charged stable ion beams for nuclear and atomic physics experiments. The design magnetic rigidity is in the range 1.5 to 15 Tm. The beam cooling system consists of stochastic cooling and electron cooling devices. With a help of an electron cooler, stored ions will be decelerated to a minimum energy of 30 MeV/u by RF cavities. The extraction system of the SRing will allow cooled ion beams to be extracted to an external target for further ion manipulations or reaction experiments. The general ion optics design and technical requirements of SRing subsystems are presented and discussed in this paper.

Electrical crosstalk in front-illuminated photodiode array with different guard ring designs for medical CT applications

International Nuclear Information System (INIS)

Ji Fan; Juntunen, Mikko; Hietanen, Iiro

2009-01-01

This paper presents electrical crosstalk studies on front-illuminated photodiode arrays for medical computed tomography (CT) applications. Crosstalk is an important factor to the system noise and image quality. The electrical crosstalk depends on silicon substrate properties and photodiode structures. The photodiode samples employed in this paper are planar processed on high-resistivity n-type silicon substrate, resulting in a p+/n-/n+ diode structure. Two types of guard ring structures are designed and applied to the same geometry of two-dimensional photodiode arrays. One structure is an n guard ring in the gap area between pixels, and the other structure is an additional p+ guard ring around each pixel together with the n guard ring. A 10 μm light spot with wavelength of 525 nm is used to scan across the surface of the photodiode array in the electrical crosstalk measurements. The electrical currents of two neighbor pixels are measured and the results are compared between two guard ring designs. The design with the p+ guard ring structure gives better electrical crosstalk suppression. Moreover, the measurement results show much smaller influence on surrounding pixels with the p+ guard ring structure in the case of disconnected pixel. Besides the electrical crosstalk, the light sensitivity within the gap area is also discussed between two guard ring designs.

Conceptual design of a linac-stretcher ring to obtain a 2-GeV continuous electron beam

International Nuclear Information System (INIS)

Cho, Y.; Holt, R.J.; Jackson, H.E.; Khoe, T.K.; Mavrogenes, G.S.

1981-01-01

In order to obtain a high duty factor, > 100 μA 2-GeV electron beam, we have designed a linac-stretcher ring system. The system is an attractive option because it draws heavily on the existing accelerator technology. The linac-stretcher ring consists of a 2-GeV SLAC-type pulsed linac which injects into a storage ring. In between linac pulses, the stored electron beam is to extract resonantly. This design differs from those discussed recently in several important respects. The storage ring includes an RF system whose purpose is to control the beam orbit and rate of extraction from the ring. With an RF system in the ring, the injection scheme consists of a few turns of synchronous transfers of beam between the linac and storage ring

Design of Piston Ring Friction Tester Apparatus

DEFF Research Database (Denmark)

Klit, Peder

2006-01-01

One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing the frictio......One of the major prerequisites for calculating piston ring friction is a good description of the tribological situation. Piston rings operate in three different lubrication regimes and the theoretical models should be capable to describe this. A very important condition for describing...... the frictional behavior of a piston ring correctly is knowledge about the amount of lubricant present. For piston rings the external load may be established by measuring the pressure distribution, i.e. the pressure drop in the piston ring package. Speed and temperature may also be established. The amount...... available is reflected in the friction absorbed in the bearing. The following properties will be measured: Oil fillm thickness - along liner (axial variation), oil film thickness - along piston ring (circumferential variation), piston tilt, temperature of piston rings and liner, pressure at piston lands...

Design of interdigital spiral and concentric capacitive sensors for materials evaluation

Science.gov (United States)

Chen, Tianming; Bowler, Nicola

2013-01-01

This paper describes the design of two circular coplanar interdigital sensors with i) a spiral interdigital configuration and ii) a concentric interdigital configuration for the nondestructive evaluation of multilayered dielectric structures. A numerical model accounting for sensor geometry, test-piece geometry and real permittivity, and metal electrode thickness has been developed to calculate the capacitance of the sensors when in contact with a planar test-piece comprising up to four layers. Compared with a disk-and-ring coplanar capacitive sensor developed previously, the interdigital configurations are predicted to have higher signal-to-noise ratio and better accuracy in materials characterization. The disk-and-ring configuration, on the other hand, possesses advantages such as deeper penetration depth and better immunity to lift-off variations.

Dust Density Distribution and Imaging Analysis of Different Ice Lines in Protoplanetary Disks

Energy Technology Data Exchange (ETDEWEB)

Pinilla, P. [Department of Astronomy/Steward Observatory, The University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Pohl, A. [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Stammler, S. M.; Birnstiel, T., E-mail: pinilla@email.arizona.edu [University Observatory, Faculty of Physics, Ludwig-Maximilians-Universität München, Scheinerstr. 1, D-81679 Münich (Germany)

2017-08-10

Recent high angular resolution observations of protoplanetary disks at different wavelengths have revealed several kinds of structures, including multiple bright and dark rings. Embedded planets are the most used explanation for such structures, but there are alternative models capable of shaping the dust in rings as it has been observed. We assume a disk around a Herbig star and investigate the effect that ice lines have on the dust evolution, following the growth, fragmentation, and dynamics of multiple dust size particles, covering from 1 μ m to 2 m sized objects. We use simplified prescriptions of the fragmentation velocity threshold, which is assumed to change radially at the location of one, two, or three ice lines. We assume changes at the radial location of main volatiles, specifically H{sub 2}O, CO{sub 2}, and NH{sub 3}. Radiative transfer calculations are done using the resulting dust density distributions in order to compare with current multiwavelength observations. We find that the structures in the dust density profiles and radial intensities at different wavelengths strongly depend on the disk viscosity. A clear gap of emission can be formed between ice lines and be surrounded by ring-like structures, in particular between the H{sub 2}O and CO{sub 2} (or CO). The gaps are expected to be shallower and narrower at millimeter emission than at near-infrared, opposite to model predictions of particle trapping. In our models, the total gas surface density is not expected to show strong variations, in contrast to other gap-forming scenarios such as embedded giant planets or radial variations of the disk viscosity.

Design of the SLC damping ring to linac transport lines

International Nuclear Information System (INIS)

Fieguth, T.H.; Murray, J.J.

1983-07-01

The first and second order optics for the damping ring to linac transport line are designed to preserve the damped transverse emittance while simultaneously compressing the bunch length of the beam to that length required for reinjection into the linac. This design, including provisions for future control of beam polarization, is described

Inspection of the Sizewll 'B' reactor coolant pump flywheels

International Nuclear Information System (INIS)

McNulty, A.L.; Cheshire, A.

1992-01-01

The Sizewell ''B'' safety case has categorised some primary circuit items as components for which failure is considered to be incredible. These Incredibility of Failure (IOF) components are particularly critical in their safety function, and specially stringent and all embracing provisions are made in their design, manufacture, inspection and operation. These provisions are such as to limit the probability of failure to levels which are so low that it does not have to be taken into account and no steps are necessary to control the consequences. The reactor coolant pump flywheel is considered to be an IOF component. Consequently there is a need for rigorous inspection during both manufacture and in service (ISI). The ISI requirement results in the need for an automated inspection. There is therefore a prerequisite to perform a Pre-Service Inspection (PSI) for baseline fingerprinting purposes. Furthermore there is a requirement that the inspection procedure, the inspection equipment and the operators are validated at the Inspection Validation Centre (IVC) of the AEA Technology laboratories at Risley. Development work is described. (author)

Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations

OpenAIRE

Flock, M.; Ruge, J. P.; Dzyurkevich, N.; Henning, Th.; Klahr, H.; Wolf, S.

2014-01-01

International audience; Aims. Recent observations by the Atacama Large Millimeter/submillimeter Array (ALMA) of disks around young stars revealed distinct asymmetries in the dust continuum emission. In this work we wish to study axisymmetric and non-axisymmetric structures that are generated by the magneto-rotational instability in the outer regions of protoplanetary disks. We combine the results of state-of-the-art numerical simulations with post-processing radiative transfer (RT) to generat...

Analysis of the Torque Ripples in Designing a Disk Type Brushless Direct Current Motor

Directory of Open Access Journals (Sweden)

A. V. Stepanov

2015-01-01

Full Text Available This paper investigates the torque ripples of disk-type low-power brushless direct current motor (BDCM with permanent magnets. In spite of numerous studies on designing of valve engines this issue is understudied as yet. The torque ripples cause noise and vibration and can significantly limit accuracy when used in instrumentation, computer technology.We consider a motor that includes a power unit consisting of a rotor and a stator. There are ferrite elements of sensor on the rotor, and the nonmagnetic disk, bonded to it, contains permanent magnets. The rotor is mounted on a rotating shaft. The stator consists of a steel casing and bonded to it non-magnetic, non-conductive disk with holes. In the disk holes from both sides are mounted armature coils. The armature winding consists of two sections each of which has 6 coils. Each adjacent coil in section has an opposite direction of winding. The coils are arranged circumferentially and are shifted relative to each other; the displacement angle between the coils of one section is equal to 2π/6 (rad. Sections are also shifted relative to each other; the angular shift is π/6 (rad. Sections are connected to the output terminals of the electronic switch. Sections of motor windings have the reverse full-wave power.The paper has investigated the steady operation at four-stroke switching and under constant load (torque. In this case, the electromagnetic torque and rotor speed are periodical functions of the rotor rotation angle. The dependencies of the averaged torque on the rotation speed have been obtained. The spectral distribution of the torque ripples at various rotor speeds of rotation has been calculated. The dependencies of the torque on the speed were studied both at constant speed and taking into account the uneven speed. Based on the research findings of disk type BDCM was computed a level of ripples amounted to 0.8 - 5%, which is quite acceptable for use in a drive. The results are useful for

The improved damping of superconductor bearings for 35 kWh superconductor flywheel energy storage system

International Nuclear Information System (INIS)

Han, Y.H.; Park, B.J.; Jung, S.Y.; Han, S.C.; Lee, W.R.; Bae, Y.C.

2013-01-01

Highlights: ► We made a 35 kWh superconductor flywheel energy storage system. ► The damping coefficient of the superconductor bearing was increased over 3000 N s/m. ► The source of damping was discussed. -- Abstract: A 35 kWh Superconductor Flywheel Energy Storage system (SFES) using hybrid bearing sets, which is composed of a high temperature superconductor (HTS) bearing and an active magnet damper (AMD), has been developed at KEPCO Research Institute (KEPRI). Damping is a source of energy loss but necessary for the stability of the flywheel system. We found that the damping of HTS bearings can be improved by thermal insulating bolts, which play a role of passive type external damper. To investigate the source of the increased damping, damping coefficients were measured with HTS bearings using insulating bolts made of three kinds of polymer materials. The damping coefficient was raised over 3000 N s/m in the case of PEEK bolts. The value was almost a quarter of the AMD. In this study, thermoelastic and Coulomb friction damping mechanisms are discussed. The main damping mechanism was the thermoelastic damping of the bolts themselves. And interfacial gap between the insulating bolt and metal chamber, which increased during the cooling process, was considered to be the cause of the anisotropic damping coefficients. Finally, the effects of the HTS bearings on the first critical speed are shown

CHEMICAL IMAGING OF THE CO SNOW LINE IN THE HD 163296 DISK

Energy Technology Data Exchange (ETDEWEB)

Qi, Chunhua; Öberg, Karin I.; Andrews, Sean M.; Wilner, David J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bergin, Edwin A. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Hughes, A. Meredith [Van Vleck Observatory, Astronomy Department, Wesleyan University, 96 Foss Hill Drive, Middletown, CT 06459 (United States); Hogherheijde, Michiel [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); D’Alessio, Paola [Centro de Radioastronomi´a y Astrofísica, Universidad Nacional Autónoma de México, 58089 Morelia, Michoacán, México (Mexico)

2015-11-10

The condensation fronts (snow lines) of H{sub 2}O, CO, and other abundant volatiles in the midplane of a protoplanetary disk affect several aspects of planet formation. Locating the CO snow line, where the CO gas column density is expected to drop substantially, based solely on CO emission profiles, is challenging. This has prompted an exploration of chemical signatures of CO freeze-out. We present ALMA Cycle 1 observations of the N{sub 2}H{sup +} J = 3−2 and DCO{sup +} J = 4−3 emission lines toward the disk around the Herbig Ae star HD 163296 at ∼0.″5 (60 AU) resolution, and evaluate their utility as tracers of the CO snow line location. The N{sub 2}H{sup +} emission is distributed in a ring with an inner radius at 90 AU, corresponding to a midplane temperature of 25 K. This result is consistent with a new analysis of optically thin C{sup 18}O data, which implies a sharp drop in CO abundance at 90 AU. Thus N{sub 2}H{sup +} appears to be a robust tracer of the midplane CO snow line. The DCO{sup +} emission also has a ring morphology, but neither the inner nor the outer radius coincide with the CO snow line location of 90 AU, indicative of a complex relationship between DCO{sup +} emission and CO freeze-out in the disk midplane. Compared to TW Hya, CO freezes out at a higher temperature in the disk around HD 163296 (25 versus 17 K in the TW Hya disk), perhaps due to different ice compositions. This highlights the importance of actually measuring the CO snow line location, rather than assuming a constant CO freeze-out temperature for all disks.

The dynamics of rings around small, irregular bodies

Science.gov (United States)

Sicardy, Bruno

2017-06-01

Stellar occultations revealed the presence of two dense rings around the Centaur object (10199) Chariklo (Braga-Ribas et al., Nature 508, 72, 2014). This is the first ring system discovered around an object that is not a giant planet, suggesting that rings may exist around numerous bodies in the solar system. Chariklo's rings roughly reside at the outer limit of the Roche zone of the body. Moreover, the main ring has sharp edges, which call for the presence of putative shepherd satellites. Those characteristics give an image of Chariklo's rings that are rather similar, in terms of dynamics, to those surrounding the gaseous planets.An important difference exists, however, between giant planets and small bodies: the formers are highly axisymmetric, while the latters can support mass anomalies (eg surface topographic features) or non-spherical shapes (eg an ellipsoidal figure of equilibrium) that involve masses, relative to the body itself, as large as 10-4-10-3.We investigate the effect of non-axisymmetric terms in the potential of the body upon a collisional debris disk that initially surrounds a small irregular body. We show that the corotation points being maxima of energy, dissipative collisions remove the particles from the corotation zone over short time scales (< 106 years). Moreover, the Lindblad resonances inside the corotation radius create torques that drive the particles onto the surface of the central body. Conversely, the outer Lindblad resonances push the disk material beyond the outer 3/2 and 2/1 Lindblad resonances.Taking as an example Chariklo's ring system, for which recent data have been obtained from stellar occultations, we show that the Lindblad resonant torques actuate over short time scales (< 106 years). This general picture offers a natural explanation of the presence of dense rings at the outer limit of Chariklo's Roche zone, and their absence closer to the body.The work leading to this results has received funding from the European

Calibration Device Designed for proof ring used in SCC Experiment

Science.gov (United States)

Hu, X. Y.; Kang, Z. Y.; Yu, Y. L.

2017-11-01

In this paper, a calibration device for proof ring used in SCC (Stress Corrosion Cracking) experiment was designed. A compact size loading device was developed to replace traditional force standard machine or a long screw nut. The deformation of the proof ring was measured by a CCD (Charge-Coupled Device) during the calibration instead of digital caliper or a dial gauge. The calibration device was verified at laboratory that the precision of force loading is ±0.1% and the precision of deformation measurement is ±0.002mm.

Flywheel Energy Storage Drive System for Wind Applications

Directory of Open Access Journals (Sweden)

Marius Constantin Georgescu

2014-09-01

Full Text Available This paper presents a wind small power plant with a Smart Storage Modular Structure (SSMS, as follows: a Short Time Storage Module (STSM based on a flywheel with Induction Motor (IM and a Medium/Long Time Storage Module (MLTSM based on a Vanadium Redox flow Battery (VRB. To control the speed and torque of the IM are used a nonlinear sensorless solution and a direct torque solution which have been compared. Now, the author proposes to replace the IM by a dc motor with permanent magnet energy injection. In this aim, are accomplished some laboratory tests.

The Karush–Kuhn–Tucker optimality conditions in minimum weight design of elastic rotating disks with variable thickness and density

Directory of Open Access Journals (Sweden)

Sanaz Jafari

2011-10-01

Full Text Available Rotating discs work mostly at high angular velocity. High speed results in large centrifugal forces in discs and induces large stresses and deformations. Minimizing weight of such disks yields various benefits such as low dead weights and lower costs. In order to attain a certain and reliable analysis, disk with variable thickness and density is considered. Semi-analytical solutions for the elastic stress distribution in rotating annular disks with uniform and variable thicknesses and densities are obtained under plane stress assumption by authors in previous works. The optimum disk profile for minimum weight design is achieved by the Karush–Kuhn–Tucker (KKT optimality conditions. Inequality constrain equation is used in optimization to make sure that maximum von Mises stress is always less than yielding strength of the material of the disk.

Characterization of sulfur deposition over the period of industrialization in Japan using sulfur isotope ratio in Japanese cedar tree rings taken from stumps.

Science.gov (United States)

Ishida, Takuya; Tayasu, Ichiro; Takenaka, Chisato

2015-07-01

We characterized the sulfur deposition history over the period of industrialization in Japan based on the sulfur isotope ratio (δ(34)S) in tree rings of Japanese cedar (Cryptomeria japonica D. Don) stumps. We analyzed and compared δ(34)S values in the rings from two types of disk samples from 170-year-old stumps that had been cut 5 years earlier (older forest stand) and from 40-year-old living trees (younger forest stand) in order to confirm the validity of using stump disks for δ(34)S analysis. No differences in δ(34)S values by age were found between the sample types, indicating that stump disks can be used for δ(34)S analysis. The δ(34)S profile in tree rings was significantly correlated with anthropogenic SO2 emissions in Japan (r = -0.76, p tree rings serve as a record of anthropogenic sulfur emissions. In addition, the values did not change largely from pre-industrialization to the 1940s (+4.2 to +6.1‰). The values before the 1940s are expected to reflect the background sulfur conditions in Japan and, thus, disks containing rings formed before the 1940s contain information about the natural environmental sulfur, which is useful for biogeochemical studies.

Moving ring field-reversed mirror blanket design considerations

International Nuclear Information System (INIS)

Wong, C.P.C.; Cheng, E.T.; Creedon, L.; Kessel, C.; Norman, J.; Schultz, K.R.

1981-01-01

A blanket design for the Moving Ring Field-Reversed Mirror Reactor (MRFRM) is presented in this paper. The design emphasis is placed on minimizing the induced radioactivities in the first-wall, blanket and shield. To this end, aluminum-alloy was selected as the reference structural material, giving dose rates two weeks after shutdown that are 3 to 4 orders of magnitude lower than comparable steel structures. The aluminum first-wall is water-cooled and thermally insulated from the high temperature SiC-clad Li 2 O tritium breeding zone. A local tritium breeding ratio of 1.05 was obtained for the design. The tritium is extracted from the Li 2 O by the use of a small dry helium purge stream through the SiC tubes. About 1 ppM hydrogen is added to the helium purge stream to enhance the tritium recovery rate. Helium at 28 atmospheres pressure is circulated through the blanket and shield, with an outlet temperature of 850 0 C, which is coupled with an existing small size closed-cycle gas turbine (CCGT) power conversion system. The spatial and temporal variations of the first-wall temperature caused by the translational movement of the plasma rings along the axis of the cylindrical reactor were evaluated. The after-heat cooling problems of the first-wall were also considered

Design of the compressor/stretcher ring of the Japanese Hadron Project

International Nuclear Information System (INIS)

Ohmori, C.; Noda, A.; Kimiya, Y.; Kihara, M.; Yamane, I.

1991-01-01

A possibility of adopting a racetrack-type design for the compressor/stretcher ring of the Japanese Hadron Project is described. This design has two long straight sections to enable to inject the H - beam and to produce a high β point for the slow extraction. (author)

Design of the compressor/stretcher ring of the Japanese Hadron Project

International Nuclear Information System (INIS)

Ohmori, C.; Noda, A.; Kamiya, Y.; Kihara, M.; Yamane, I.

1991-02-01

A possibility of adopting a racetrack-type design for the compressor/stretcher ring of the Japanese Hadron Project is described. This design has two long straight sections to enable to inject the H - beam and to produce a high β point for the slow extraction. (author)

Conceptual Design of ILC Damping Ring Wiggler Straight Vacuum System

International Nuclear Information System (INIS)

Marks, S.; Kennedy, K.; Plate, D.; Schlueter, R.D.; Zisman, M.

2007-01-01

The positron and electron damping rings for the International Linear Collider will contain long straight sections consisting of twenty wiggler/quadrupole pairs. The wigglers will be based upon the CESR superconducting design. There are a number of challenges associated with the design of the wiggler straight vacuum system, in particular, the absorption of photon power generated by the wigglers. This paper will present the overall conceptual design of the wiggler straight vacuum system developed for the ILC Reference Design Report. Particular emphasis will be placed on photon power load calculations and the absorber design

Saturn's Rings Edge-on

Science.gov (United States)

1995-01-01

In one of nature's most dramatic examples of 'now-you see-them, now-you-don't', NASA's Hubble Space Telescope captured Saturn on May 22, 1995 as the planet's magnificent ring system turned edge-on. This ring-plane crossing occurs approximately every 15 years when the Earth passes through Saturn's ring plane.For comparison, the top picture was taken by Hubble on December 1, 1994 and shows the rings in a more familiar configuration for Earth observers.The bottom picture was taken shortly before the ring plane crossing. The rings do not disappear completely because the edge of the rings reflects sunlight. The dark band across the middle of Saturn is the shadow of the rings cast on the planet (the Sun is almost 3 degrees above the ring plane.) The bright stripe directly above the ring shadow is caused by sunlight reflected off the rings onto Saturn's atmosphere. Two of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are, from left to right, Tethys (slightly above the ring plane) and Dione.This observation will be used to determine the time of ring-plane crossing and the thickness of the main rings and to search for as yet undiscovered satellites. Knowledge of the exact time of ring-plane crossing will lead to an improved determination of the rate at which Saturn 'wobbles' about its axis (polar precession).Both pictures were taken with Hubble's Wide Field Planetary Camera 2. The top image was taken in visible light. Saturn's disk appears different in the bottom image because a narrowband filter (which only lets through light that is not absorbed by methane gas in Saturn's atmosphere) was used to reduce the bright glare of the planet. Though Saturn is approximately 900 million miles away, Hubble can see details as small as 450 miles across.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and

Peak power reduction and energy efficiency improvement with the superconducting flywheel energy storage in electric railway system

Science.gov (United States)

Lee, Hansang; Jung, Seungmin; Cho, Yoonsung; Yoon, Donghee; Jang, Gilsoo

2013-11-01

This paper proposes an application of the 100 kWh superconducting flywheel energy storage systems to reduce the peak power of the electric railway system. The electric railway systems have high-power characteristics and large amount of regenerative energy during vehicles’ braking. The high-power characteristic makes operating cost high as the system should guarantee the secure capacity of electrical equipment and the low utilization rate of regenerative energy limits the significant energy efficiency improvement. In this paper, it had been proved that the peak power reduction and energy efficiency improvement can be achieved by using 100 kWh superconducting flywheel energy storage systems with the optimally controlled charging or discharging operations. Also, economic benefits had been assessed.

Design of all-optical flip-flop by using optical bistability in passive micro-rings

International Nuclear Information System (INIS)

Karimi, M.; Abolfazli, M. J.; Rouholamini Nejad, H.; Bahrampour, A.

2007-01-01

In this paper at first, Optical bistability in the micro ring resonators in the presence of Kerr and two-photon absorption effects is studied and also, attenuation in micro rings with these nonlinear effects is calculated. An all-optical R-S flip-flop is designed by using optical bistability. Conditions for SET and RESET signals are calculated and their dependences on the optical parameters of micro rings are investigated.

Modeling and Design Guidelines for P⁺ Guard Rings in Lightly Doped CMOS Substrates

DEFF Research Database (Denmark)

Shen, Ming; Mikkelsen, Jan H.; Zhang, Ke

2013-01-01

of ${rm P}^{+}$ guard rings in terms of S-parameters, which is useful for substrate noise mitigation in mixed-signal system-on-chips. Validation of the model has been done by both electromagnetic simulation and experimental results from guard rings implemented using a standard 0.18-$mu{rm m}$ CMOS process....... In addition, design guidelines have been drawn for minimizing the guard ring size while maintaining the noise suppression performance....

Distributed Cooperative Control of Multi Flywheel Energy Storage System for Electrical Vehicle Fast Charging Stations

DEFF Research Database (Denmark)

Sun, Bo; Dragicevic, Tomislav; Quintero, Juan Carlos Vasquez

2015-01-01

Plug-in electrical vehicles will play a critical role in future smart grid and sudden connection of electrical vehicles chargers may cause huge power-peaks with high slew-rates on grid. In order to cope with this issue, this paper applies a distributed cooperative control for fast charging station...... with dedicated paralleled flywheel-based energy storage system. The distributed DC-bus signaling method is employed in the power coordination of grid and flywheel converters, and a distributed secondary controller generates DC voltage correction term to adjust the local voltage set-point through a dynamic...... consensus based voltage observer by communicating with its neighbors. The control system can realize the power balancing and DC voltage regulation with low reliance on communications. Finally, real-time hardware-in-the-loop results have been reported in order to verify the feasibility of proposed approach....

ALMA REVEALS THE ANATOMY OF THE mm-SIZED DUST AND MOLECULAR GAS IN THE HD 97048 DISK

Energy Technology Data Exchange (ETDEWEB)

Walsh, Catherine; Maud, Luke T. [Leiden Observatory, Leiden University, P.O. Box 9531, 2300 RA Leiden (Netherlands); Juhász, Attila [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Meeus, Gwendolyn [Departamento de Física Teórica, Universidad Autonoma de Madrid, Campus Cantoblanco, E-28049 Madrid (Spain); Dent, William R. F. [Joint ALMA Observatory (JAO), Alonso de Córdova 3107, Vitacura, Santiago (Chile); Aikawa, Yuri [Center for Computer Sciences, University of Tsukuba, 305-8577 Tsukuba (Japan); Millar, Tom J. [School of Mathematics and Physics, Queen’s University Belfast, University Road, Belfast BT7 1NN (United Kingdom); Nomura, Hideko, E-mail: cwalsh@strw.leidenuniv.nl, E-mail: c.walsh1@leeds.ac.uk [Department of Earth and Planetary Science, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, 152-8551 Tokyo (Japan)

2016-11-10

Transitional disks show a lack of excess emission at infrared wavelengths due to a large dust cavity, that is often corroborated by spatially resolved observations at ∼ mm wavelengths. We present the first spatially resolved ∼ mm-wavelength images of the disk around the Herbig Ae/Be star, HD 97048. Scattered light images show that the disk extends to ≈640 au. ALMA data reveal a circular-symmetric dusty disk extending to ≈350 au, and a molecular disk traced in CO J = 3-2 emission, extending to ≈750 au. The CO emission arises from a flared layer with an opening angle ≈30°–40°. HD 97048 is another source for which the large (∼ mm-sized) dust grains are more centrally concentrated than the small (∼ μ m-sized) grains and molecular gas, likely due to radial drift. The images and visibility data modeling suggest a decrement in continuum emission within ≈50 au, consistent with the cavity size determined from mid-infrared imaging (34 ± 4 au). The extracted continuum intensity profiles show ring-like structures with peaks at ≈50, 150, and 300 au, with associated gaps at ≈100 and 250 au. This structure should be confirmed in higher-resolution images (FWHM ≈ 10–20 au). These data confirm the classification of HD 97048 as a transitional disk that also possesses multiple ring-like structures in the dust continuum emission. Additional data are required at multiple and well-separated frequencies to fully characterize the disk structure, and thereby constrain the mechanism(s) responsible for sculpting the HD 97048 disk.

ALMA Reveals the Anatomy of the mm-sized Dust and Molecular Gas in the HD 97048 Disk

Science.gov (United States)

Walsh, Catherine; Juhász, Attila; Meeus, Gwendolyn; Dent, William R. F.; Maud, Luke T.; Aikawa, Yuri; Millar, Tom J.; Nomura, Hideko

2016-11-01

Transitional disks show a lack of excess emission at infrared wavelengths due to a large dust cavity, that is often corroborated by spatially resolved observations at ˜ mm wavelengths. We present the first spatially resolved ˜ mm-wavelength images of the disk around the Herbig Ae/Be star, HD 97048. Scattered light images show that the disk extends to ≈640 au. ALMA data reveal a circular-symmetric dusty disk extending to ≈350 au, and a molecular disk traced in CO J = 3-2 emission, extending to ≈750 au. The CO emission arises from a flared layer with an opening angle ≈30°-40°. HD 97048 is another source for which the large (˜ mm-sized) dust grains are more centrally concentrated than the small (˜μm-sized) grains and molecular gas, likely due to radial drift. The images and visibility data modeling suggest a decrement in continuum emission within ≈50 au, consistent with the cavity size determined from mid-infrared imaging (34 ± 4 au). The extracted continuum intensity profiles show ring-like structures with peaks at ≈50, 150, and 300 au, with associated gaps at ≈100 and 250 au. This structure should be confirmed in higher-resolution images (FWHM ≈ 10-20 au). These data confirm the classification of HD 97048 as a transitional disk that also possesses multiple ring-like structures in the dust continuum emission. Additional data are required at multiple and well-separated frequencies to fully characterize the disk structure, and thereby constrain the mechanism(s) responsible for sculpting the HD 97048 disk.

ALMA REVEALS THE ANATOMY OF THE mm-SIZED DUST AND MOLECULAR GAS IN THE HD 97048 DISK

International Nuclear Information System (INIS)

Walsh, Catherine; Maud, Luke T.; Juhász, Attila; Meeus, Gwendolyn; Dent, William R. F.; Aikawa, Yuri; Millar, Tom J.; Nomura, Hideko

2016-01-01

Transitional disks show a lack of excess emission at infrared wavelengths due to a large dust cavity, that is often corroborated by spatially resolved observations at ∼ mm wavelengths. We present the first spatially resolved ∼ mm-wavelength images of the disk around the Herbig Ae/Be star, HD 97048. Scattered light images show that the disk extends to ≈640 au. ALMA data reveal a circular-symmetric dusty disk extending to ≈350 au, and a molecular disk traced in CO J = 3-2 emission, extending to ≈750 au. The CO emission arises from a flared layer with an opening angle ≈30°–40°. HD 97048 is another source for which the large (∼ mm-sized) dust grains are more centrally concentrated than the small (∼ μ m-sized) grains and molecular gas, likely due to radial drift. The images and visibility data modeling suggest a decrement in continuum emission within ≈50 au, consistent with the cavity size determined from mid-infrared imaging (34 ± 4 au). The extracted continuum intensity profiles show ring-like structures with peaks at ≈50, 150, and 300 au, with associated gaps at ≈100 and 250 au. This structure should be confirmed in higher-resolution images (FWHM ≈ 10–20 au). These data confirm the classification of HD 97048 as a transitional disk that also possesses multiple ring-like structures in the dust continuum emission. Additional data are required at multiple and well-separated frequencies to fully characterize the disk structure, and thereby constrain the mechanism(s) responsible for sculpting the HD 97048 disk.

Space-based Coronagraphic Imaging Polarimetry of the TW Hydrae Disk: Shedding New Light on Self-shadowing Effects

Science.gov (United States)

Poteet, Charles A.; Chen, Christine H.; Hines, Dean C.; Perrin, Marshall D.; Debes, John H.; Pueyo, Laurent; Schneider, Glenn; Mazoyer, Johan; Kolokolova, Ludmilla

2018-06-01

We present Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer coronagraphic imaging polarimetry of the TW Hydrae protoplanetary disk. These observations simultaneously measure the total and polarized intensity, allowing direct measurement of the polarization fraction across the disk. In accord with the self-shadowing hypothesis recently proposed by Debes et al., we find that the total and polarized intensity of the disk exhibits strong azimuthal asymmetries at projected distances consistent with the previously reported bright and dark ring-shaped structures (∼45–99 au). The sinusoidal-like variations possess a maximum brightness at position angles near ∼268°–300° and are up to ∼28% stronger in total intensity. Furthermore, significant radial and azimuthal variations are also detected in the polarization fraction of the disk. In particular, we find that regions of lower polarization fraction are associated with annuli of increased surface brightness, suggesting that the relative proportion of multiple-to-single scattering is greater along the ring and gap structures. Moreover, we find strong (∼20%) azimuthal variation in the polarization fraction along the shadowed region of the disk. Further investigation reveals that the azimuthal variation is not the result of disk flaring effects, but is instead from a decrease in the relative contribution of multiple-to-single scattering within the shadowed region. Employing a two-layer scattering surface, we hypothesize that the diminished contribution in multiple scattering may result from shadowing by an inclined inner disk, which prevents direct stellar light from reaching the optically thick underlying surface component.

The Interplay between Radiation Pressure and the Photoelectric Instability in Optically Thin Disks of Gas and Dust

Science.gov (United States)

Richert, Alexander J. W.; Lyra, Wladimir; Kuchner, Marc J.

2018-03-01

In optically thin disks, dust grains are photoelectrically stripped of electrons by starlight, heating nearby gas and possibly creating a dust clumping instability—the photoelectric instability (PeI)—that significantly alters global disk structure. In the current work, we use the Pencil Code to perform the first numerical models of the PeI that include stellar radiation pressure on dust grains in order to explore the parameter regime in which the instability operates. In some models with low gas and dust surface densities, we see a variety of dust structures, including sharp concentric rings. In the most gas- and dust-rich models, nonaxisymmetric clumps, arcs, and spiral arms emerge that represent dust surface density enhancements of factors of ∼5–20. In one high gas surface density model, we include a large, low-order gas viscosity and find that it observably smooths the structures that form in the gas and dust, suggesting that resolved images of a given disk may be useful for deriving constraints on the effective viscosity of its gas. Our models show that radiation pressure does not preclude the formation of complex structure from the PeI, but the qualitative manifestation of the PeI depends strongly on the parameters of the system. The PeI may provide an explanation for unusual disk morphologies, such as the moving blobs of the AU Mic disk, the asymmetric dust distribution of the 49 Ceti disk, and the rings and arcs found in the HD 141569A disk.

NASA Lunar and Meteorite Sample Disk Program

Science.gov (United States)

Foxworth, Suzanne

2017-01-01

The Lunar and Meteorite Sample Disk Program is designed for K-12 classroom educators who work in K-12 schools, museums, libraries, or planetariums. Educators have to be certified to borrow the Lunar and Meteorite Sample Disks by attending a NASA Certification Workshop provided by a NASA Authorized Sample Disk Certifier.

Design of a dual linear polarization antenna using split ring resonators at X-band

Science.gov (United States)

Ahmed, Sadiq; Chandra, Madhukar

2017-11-01

Dual linear polarization microstrip antenna configurations are very suitable for high-performance satellites, wireless communication and radar applications. This paper presents a new method to improve the co-cross polarization discrimination (XPD) for dual linear polarized microstrip antennas at 10 GHz. For this, three various configurations of a dual linear polarization antenna utilizing metamaterial unit cells are shown. In the first layout, the microstrip patch antenna is loaded with two pairs of spiral ring resonators, in the second model, a split ring resonator is placed between two microstrip feed lines, and in the third design, a complementary split ring resonators are etched in the ground plane. This work has two primary goals: the first is related to the addition of metamaterial unit cells to the antenna structure which permits compensation for an asymmetric current distribution flow on the microstrip antenna and thus yields a symmetrical current distribution on it. This compensation leads to an important enhancement in the XPD in comparison to a conventional dual linear polarized microstrip patch antenna. The simulation reveals an improvement of 7.9, 8.8, and 4 dB in the E and H planes for the three designs, respectively, in the XPD as compared to the conventional dual linear polarized patch antenna. The second objective of this paper is to present the characteristics and performances of the designs of the spiral ring resonator (S-RR), split ring resonator (SRR), and complementary split ring resonator (CSRR) metamaterial unit cells. The simulations are evaluated using the commercial full-wave simulator, Ansoft High-Frequency Structure Simulator (HFSS).

Magnet design for a low-emittance storage ring

Science.gov (United States)

Johansson, Martin; Anderberg, Bengt; Lindgren, Lars-Johan

2014-01-01

The MAX IV 3 GeV storage ring, currently under construction, pursues the goal of low electron beam emittance by using a multi-bend achromat magnet lattice, which is realised by having several consecutive magnet elements precision-machined out of a common solid iron block, 2.3–3.4 m long. With this magnet design solution, instead of having 1320 individual magnets, the MAX IV 3 GeV storage ring is built up using 140 integrated ‘magnet block’ units, containing all these magnet elements. Major features of this magnet block design are compactness, vibration stability and that the alignment of magnet elements within each unit is given by the mechanical accuracy of the CNC machining rather than individual field measurement and adjustment. This article presents practical engineering details of implementing this magnet design solution, and mechanical + magnetic field measurement results from the magnet production series. At the time of writing (spring 2014), the production series, which is totally outsourced to industry, is roughly half way through, with mechanical/magnetic QA conforming to specifications. It is the conclusion of the authors that the MAX IV magnet block concept, which has sometimes been described as new or innovative, is from a manufacturing point of view simply a collection of known mature production methods and measurement procedures, which can be executed at fixed cost with a low level of risk. PMID:25177980

TRANSIENT ANALYSIS OF WIND DIESEL POWER SYSTEM WITH FLYWHEEL ENERGY STORAGE

Directory of Open Access Journals (Sweden)

S. SUJITH

2017-10-01

Full Text Available Wind-Diesel Hybrid power generation is a viable alternative for generating continuous power to isolated power system areas which have inconsistent but potential wind power. The unpredictable nature of variable power from Wind generator to the system is compensated by Diesel generator, which supplies the deficit in generated power from wind to meet the instantaneous system load. However, one of the major challenges for such a system is the higher probability of transients in the form of wind and load fluctuations. This paper analyses the application of Flywheel Energy storage system (FESS to meet the transients during wind-speed and load fluctuations around high wind operation. The power system architecture, the distributed control mechanism governing the flow of power transfer and the modelling of major system components has been discussed and the system performances have been validated using MATLAB /Simulink software. Two cases of transient stages around the high wind system operation are discussed. The simulation results highlight the effective usage of FESS in reducing the peak overshoot of active power transients, smoothes the active power curves and helps in reducing the diesel consumption during the flywheel discharge period, without affecting the continuous power supply for meeting the instantaneous load demand.

Disk

NARCIS (Netherlands)

P.A. Boncz (Peter); L. Liu (Lei); M. Tamer Özsu

2008-01-01

htmlabstractIn disk storage, data is recorded on planar, round and rotating surfaces (disks, discs, or platters). A disk drive is a peripheral device of a computer system, connected by some communication medium to a disk controller. The disk controller is a chip, typically connected to the CPU of

Multi-Canister overpack necessity of the rupture disk

International Nuclear Information System (INIS)

SMITH, K.E.

1998-01-01

The Multi-Canister Overpack (MCO) rupture disk precludes the MCO from pressurization above the design limit during transport from the K Basins to the Cold Vacuum Drying (CVD) Facility and prior to connection of the CVD process piping. Removal of the rupture disk from the MCO design would: (a) result in unacceptable dose consequences in the event a thermal runaway accident occurred; (b) increase residual risk; and (c) remove a degree of specificity from the dose calculations. The potential cost savings of removing the rupture disk from the MCO design is offset by the cost of design modifications, changes to hazard analyses and safety analyses, and changes to existing documentation. Retaining the rupture disk mitigates the consequences of MCO overpressurization, and considering the overall economic impacts to the SNF Project, is the most cost effective approach

Conceptual Design Report. Antiproton - Proton Collider Upgrade 20 GeV Rings. Technical Components and Civil Construction May, 1988

Energy Technology Data Exchange (ETDEWEB)

None

1988-05-01

This report contains a description of the design and cost estimate of two new 20 GeV rings which will be required to support the upgrade of the Fermilab Collider with a luminosity goal of 5x10 ³¹ cm^-2s^-1. The new rings include an antiproton post-accumulator, denoted the Antiproton Super Booster (ASB), and a proton post-booster, denoted the Proton Super Booster (PSB). The siting of the rings is shown in Figure I-1. Both rings are capable of operation at 20 GeV, eliminating the need for ever again injecting beam into the Main Ring below transition, and significantly enhancing Main Ring performance. The Antiproton Super Booster is designed to accept and accumulate up to 4x10¹² antiprotons from the existing Antiproton Accumulator, and deliver them to the Main Ring at 20 GeV for acceleration and injection into the Collider. It is also designed to accept diluted antiprotons from the Main Ring at 20 GeV for recooling. The PSB accepts 8.9 GeV protons from the existing Booster and accelerates them to 20 GeV for injection into the Main Ring. The PSB is designed to operate at 5 Hz. The siting shown in Figure I-1 has the attractive feature that it removes all Main Ring injection hardware from the AO straight section, opening the possibility of installing a third proton-antiproton interaction region in the Tevatron Collider.

Modeling the HD 32297 Debris Disk With Far-Infrared Herschel Data

Science.gov (United States)

Donaldson, J.K.; Lebreton, J.; Roberge, A.; Augereau, J.-C.; Krivov, A. V.

2013-01-01

HD 32297 is a young A-star (approx. 30 Myr) 112 pc away with a bright edge-on debris disk that has been resolved in scattered light. We observed the HD 32297 debris disk in the far-infrared and sub-millimeter with the Herschel Space Observatory PACS and SPIRE instruments, populating the spectral energy distribution (SED) from 63 to 500 micron..We aimed to determine the composition of dust grains in the HD 32297 disk through SED modeling, using geometrical constraints from the resolved imaging to break the degeneracies inherent in SED modeling. We found the best fitting SED model has two components: an outer ring centered around 110 AU, seen in the scattered light images, and an inner disk near the habitable zone of the star. The outer disk appears to be composed of grains>2 micron consisting of silicates, carbonaceous material, and water ice with an abundance ratio of 1:2:3 respectively and 90% porosity. These grains appear consistent with cometary grains, implying the underlying planetesimal population is dominated by comet-like bodies. We also discuss the 3.7 sigma detection of [C ii] emission at 158 micron with the Herschel PACS instrument, making HD 32297 one of only a handful of debris disks with circumstellar gas detected

Development and verification of a reciprocating test rig designed for investigation of piston ring tribology

DEFF Research Database (Denmark)

Pedersen, Michael Torben; Imran, Tajammal; Klit, Peder

2009-01-01

This paper describes the development and verification of a reciprocating test rig, which was designed to study the piston ring tribology. A crank mechanism is used to generate a reciprocating motion for a moving plate, which acts as the liner. A stationary block acting as the ring package is loaded......, which is suitable for the study of piston ring tribology....

Long-lived Dust Asymmetries at Dead Zone Edges in Protoplanetary Disks

Energy Technology Data Exchange (ETDEWEB)

Miranda, Ryan [Cornell Center for Astrophysics and Planetary Science, Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Li, Hui; Li, Shengtai; Jin, Sheng, E-mail: rjm456@cornell.edu [Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2017-02-01

A number of transition disks exhibit significant azimuthal asymmetries in thermal dust emission. One possible origin for these asymmetries is dust trapping in vortices formed at the edges of dead zones. We carry out high-resolution, two-dimensional hydrodynamic simulations of this scenario, including the effects of dust feedback. We find that, although feedback weakens the vortices and slows down the process of dust accumulation, the dust distribution in the disk can nonetheless remain asymmetric for many thousands of orbits. We show that even after 10{sup 4} orbits, or 2.5 Myr when scaled to the parameters of Oph IRS 48 (a significant fraction of its age), the dust is not dispersed into an axisymmetric ring, in contrast to the case of a vortex formed by a planet. This is because accumulation of mass at the dead zone edge constantly replenishes the vortex, preventing it from being fully destroyed. We produce synthetic dust emission images using our simulation results. We find that multiple small clumps of dust may be distributed azimuthally. These clumps, if not resolved from one another, appear as a single large feature. A defining characteristic of a disk with a dead zone edge is that an asymmetric feature is accompanied by a ring of dust located about twice as far from the central star.

A Virtual Tool for Minimum Cost Design of a Wind Turbine Tower with Ring Stiffeners

Directory of Open Access Journals (Sweden)

Fatih Karpat

2013-07-01

Full Text Available Currently, renewable energy resources are becoming more important to reduce greenhouse gas emissions and increase energy efficiency. Researchers have focused on all components of wind turbines to increase reliability and minimize cost. In this paper, a procedure including a cost analysis method and a particle swarm optimization algorithm has been presented to efficiently design low cost steel wind turbine towers. A virtual tool is developed in MATLAB for the cost optimization of wind turbine steel towers with ring stiffeners using a particle swarm optimization algorithm. A wind turbine tower optimization problem in the literature is solved using the developed computer program. In the optimization procedure the optimization results match very well with the optimization results obtained previously. The wall thickness of the shell segments and the dimensions of the ring stiffeners are selected as the design variables, and the limits of the local buckling for the flat ring stiffeners, the local shell buckling limit, the panel ring buckling limit and the limitation of the frequency are considered the design constraints. Numerical examples are presented to understand the impacts of the design variables on the total cost of the wind turbine tower.

Element analysis and radioactivity measurement within a wood disk by neutron activation analysis

International Nuclear Information System (INIS)

Hayashi, Y.; Ikeue, N.; Tanoi, K.; Tange, T.; Yagi, H.; Nakanishi, T.M.

2003-01-01

16 elements and the radioactivity of 210 Pb in a wood disk, across the annual rings have been analyzed to find out a promising tool for dendrochronology (chronology of wood) both for a Japanese wood, Cryptomeria japonica, and for an Indonesian rain forest wood, Alstonia, which does not form annual rings because of the relatively constant climate of the rain forest. As a result, only Mg concentration showed similar, smooth decreasing tendency in both wood species. The smooth change of the Mg concentration across the annual rings along with the growth suggested the possibility of the Mg concentration determination as a promising dendrochronological tool. (author)

Four giga joule flywheel motor-generator for JT-60 toroidal field coil power supply system

International Nuclear Information System (INIS)

Matsukawa, T.; Kanke, M.; Shimada, R.; Yoshida, Y.; Yamashita, K.; Nakayama, T.

1986-01-01

A fusion test reactor often needs motor-generators as a power source in order to reduce disturbances to utility lines. The toroidal field coil power supply system of JT-60 also adopted a motor-generator for this purpose. The motor-generator started operation in April, 1985 at Japan Atomic Energy Research Institute together with the whole system. The motor-generator has several special features both electrically and mechanically. One electrical feature is that it is used as a pulse source of large current and power for periodic short-time duty. A mechanical feature is that a large flywheel is directly coupled to the motor-generator shaft and operated intermittently and at high speed. Therefore detailed investigations were carried out concerning constitution, characteristics as well as the coordination with the system performance. This paper describes the outlines of the flywheel motor-generator and discusses several topics

BEAM-LOSS DRIVEN DESIGN OPTIMIZATION FOR THE SPALLATION NEUTRON SOURCE (SNS) RING.

Energy Technology Data Exchange (ETDEWEB)

WEI,J.; BEEBE-WANG,J.; BLASKIEWICZ,M.; CAMERON,P.; DANBY,G.; GARDNER,C.J.; JACKSON,J.; LEE,Y.Y.; LUDEWIG,H.; MALITSKY,N.; RAPARIA,D.; TSOUPAS,N.; WENG,W.T.; ZHANG,S.Y.

1999-03-29

This paper summarizes three-stage design optimization for the Spallation Neutron Source (SNS) ring: linear machine design (lattice, aperture, injection, magnet field errors and misalignment), beam core manipulation (painting, space charge, instabilities, RF requirements), and beam halo consideration (collimation, envelope variation, e-p issues etc.).

Beam-Loss Driven Design Optimization for the Spallation Neutron Source (SNS) Ring

International Nuclear Information System (INIS)

Wei, J.

1999-01-01

This paper summarizes three-state design optimization for the Spallation Neutron Source (SNS) ring: linear machine design (lattice, aperture, injection, magnet field errors and misalignment), beam core manipulation (painting, space charge, instabilities, RF requirements), and beam halo consideration (collimation, envelope variation, e-p issues etc.)

A Low-Energy Ring Lattice Design

International Nuclear Information System (INIS)

Cai, Yunhai

2002-01-01

The PEP-N project at SLAC [1] consists of a Very Low-Energy small electron Ring (VLER) that will collide with the low-energy 3.1 GeV positron beam (LER) of PEP-II, producing center-of-mass energies between the 1.1 GeV and the J/ψ. The beams will collide head-on and will be separated in the detector magnetic field which is part of the Interaction Region [2]. The IP β functions were chosen such as to optimize both luminosity and beam-beam tune shifts, while keeping the LER tune shifts small. This paper describes the lattice design of the VLER for the ''baseline'' at 500 MeV

Solid-state disk amplifiers for fusion-laser systems

Energy Technology Data Exchange (ETDEWEB)

Martin, W.E.; Trenholme, J.B.; Linford, G.J.; Yarema, S.M.; Hurley, C.A.

1981-09-01

We review the design, performance, and operation of large-aperture (10 to 46 cm) solid-state disk amplifiers for use in laser systems. We present design data, prototype tests, simulations, and projections for conventional cylindrical pump-geometry amplifiers and rectangular pump-geometry disk amplifiers. The design of amplifiers for the Nova laser system is discussed.

Design of the WNR proton storage ring lattice

International Nuclear Information System (INIS)

Cooper, R.K.; Lawrence, G.P.

1977-01-01

The Weapons Neutron Research Facility, now approaching operational status, is a pulsed neutron time-of-flight facility utilizing bursts of 800 MeV protons from the LAMPF linac. The protons strike a heavy metal target and produce a broad energy spectrum of neutrons via spallation reactions. Ideally the width of the proton pulse should approach a delta function in order to achieve good neutron energy resolution. Practically, the shortest pulse that can be employed in the facility is that produced by a single LAMPF micropulse, which, at design current, contains approximately 5 x 10 8 protons. With the addition of a storage ring capable of accumulating many micropulses, this intensity can be increased, as can the repetition rate. Moreover, by storing an unbunched beam, a low repetition rate, very intense proton burst can be generated. This latter mode of usage allows neutron time-of-flight studies using large neutron targets, for which pulse lengths of the order of several hundred nanoseconds are suitable. The primary goals of the ring are reported: (i) to increase the intensity of the burst to 10 11 protons while retaining a short pulse length; (ii) to increase the repetition rate of the bursts by at least a factor of six; and (iii) to store as many particles as possible, uniformly distributed around the ring

Electrochemical Batteries: Flywheels for temporary energy storage; Baterias electromecanicas: volantes de inercia para el almacenamiento temporal de energia

Energy Technology Data Exchange (ETDEWEB)

Pena Alzola, R.; Sebastian Fernandez, R.

2008-07-01

In the Electromechanical batteries (EMB) a flywheel stores mechanical energy that interchanges in form of electrical energy by means of an electrical machine with a bidirectional power converter. EMB are suitable whenever numerous charge and recharge cycles (hundred of thousands) are needed with medium to high power (kW to MW) during short periods (seconds). The materials of the flywheel, the type of the electrical machine, the type of the bearings and the atmosphere inside the housing determine the energy efficiency of the EMB. EMB are commercially available with more than a dozen of manufacturers. Amongst the applications of BEM are: uninterrupted power supplies, hybrid power systems, power grids feeding trains, hybrid vehicles and space satellites. (Author) 15 refs.

Bearing design for flywheel energy storage using high-TC superconductors

Science.gov (United States)

Hull, John R.; Mulcahy, Thomas M.

2000-01-01

A high temperature superconductor material bearing system (38) This system (38) includes a rotor (50) having a ring permanent magnet (60), a plurality of permanent magnets (16, 20 and 70) for interacting to generate levitation forces for the system (38). This group of magnets are a push/pull bearing (75). A high temperature superconductor structure (30) interacts with the ting permanent magnet (60) to provide stabilizing forces for the system (38).

Two-Level Control for Fast Electrical Vehicle Charging Stations with Multi Flywheel Energy Storage System

DEFF Research Database (Denmark)

SUN, BO; Dragicevic, Tomislav; Vasquez, Juan Carlos

2015-01-01

This paper applies a hierarchical control for a fast charging station (FCS) composed of paralleled PWM rectifier and dedicated paralleled multiple flywheel energy storage systems (FESSs), in order to mitigate peak power shock on grid caused by sudden connection of electrical vehicle (EV) chargers...

Modeling of the hydrogen maser disk in MWC 349

Science.gov (United States)

Ponomarev, Victor O.; Smith, Howard A.; Strelnitski, Vladimir S.

1994-04-01

Maser amplification in a Keplerian circumstellar disk seen edge on-the idea put forward by Gordon (1992), Martin-Pintado, & Serabyn (1992), and Thum, Martin-Pintado, & Bachiller (1992) to explain the millimeter hydrogen recombination lines in MWC 349-is further justified and developed here. The double-peaked (vs. possible triple-peaked) form of the observed spectra is explained by the reduced emission from the inner portion of the disk, the portion responsible for the central ('zero velocity') component of a triple-peaked spectrum. Radial gradient of electron density and/or free-free absorption within the disk are identified as the probable causes of this central 'hole' in the disk and of its opacity. We calculate a set of synthetic maser spectra radiated by a homogeneous Keplerian ring seen edge-on and compare them to the H30-alpha observations of Thum et al., averaged over about 1000 days. We used a simple graphical procedure to solve an inverse problem and deduced the probable values of some basic disk and maser parameters. We find that the maser is essentially unsaturated, and that the most probable values of electron temperature. Doppler width of the microturbulence, and electron density, all averaged along the amplification path are, correspondingly, Te less than or equal to 11,000 K, Vmicro less than or equal to 14 km/s, ne approx. = (3 +/- 2) x 107/cu cm. The model shows that radiation at every frequency within the spectrum arises in a monochromatic 'hot spot.' The maximum optical depth within the 'hot spot' producing radiation at the spectral peak maximum is taumax approx. = 6 +/- 1; the effective width of the masing ring is approx. = 0.4-0.7 times its outer diameter; the size of the 'hot spot' responsible for the radiation at the spectral peak frequency is approx. = 0.2-0.3 times the distance between the two 'hot spots' corresponding to two peaks. An important derivation of our model is the dynamical mass of the central star, M* approx. = 26 solar masses

Saturn’s ring temperatures at equinox

Science.gov (United States)

Spilker, Linda J.; Ferrari, C.; Morishima, R.

2013-10-01

Modeling the thermal emission of Saturn's rings is challenging due to the numerous heating sources as well as the structural properties of the disk and of the particles that are closely related. At equinox, however, the main rings are externally heated by Saturn alone and the problem is somewhat simplified. We test the abilities of our current models to reproduce the temperatures observed with the Cassini CIRS instrument around equinox in August 2009. A simple semi-analytic model which includes mutual shadowing effects can mostly explain the radial profile of the equinox ring temperatures, except the model predicts lower temperatures than those observed for the A ring. The temperature variation at a given saturnocentric radius is primarily caused by observational geometry variations relative to Saturn. The observed temperature increases with decreasing Saturn-ring-observer angle. In addition, we found evidence that the leading hemispheres of particles are warmer than the trailing hemispheres at least for the C ring and probably for the A and B rings as well. This is explained if some fraction of particles has spin rates lower than the synchronous rotation rate as predicted by N-body simulations. The spin model for a monolayer ring (Ferrari, C., Leyrat, C., 2006, Astron. Astrophys. 447, 745-760) can fit the temperature variations with spacecraft longitude observed in the C ring with currently known thermal properties and a mixing of slow and fast rotators. The multilayer model (Morishima, R., Salo, H., Ohtsuki, K., 2009, Icarus 201, 634-654) can reproduce the temperatures of the B and C rings but gives A ring temperatures that are significantly lower than those observed as does the simple semi-analytic model. More advanced models which take into account self-gravity wakes may explain the A ring temperature behavior.

1998 Annual Study Report. Research and development of power storage by high-temperature superconducting flywheels (research and development of permanent magnet); 1998 nendo seika hokokusho. Koon chodendo flywheel denryoku chozo kenkyu kaihatsu (eikyu jishaku no kenkyu kaihatsu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

The permanent magnets have been investigated and developed, for eventual commercialization of a 10 MWh power storage system by high-temperature superconducting flywheel. The permanent magnet rotors have been already developed in the previous years using a praseodymium-based magnet (Pr magnet) and neodymium-based sintered magnet (Nd sintered magnet), and the target rotational speed of 30,000 rpm has been attained. For development of the magnetic circuit to produce a stronger and smoother magnetic field, magnetic flux density of the Nd sintered magnet is measured. It shows a lower magnetic flux irregularity than the Pd magnet, but there is still room for further improvement. For development of large-size permanent magnet fabrication techniques, it is confirmed that the large-size Nd sintered magnet can be easily magnetized by partial magnetizing, as is the case with the Pr magnet. In this year, the irregular magnetic flux is three-dimensionally simulated, based on the results obtained in the previous years, to find that the simulated results are in good agreement with the observed ones. The measures to solve the problems are also investigated. It is also confirmed that the large-size ring magnet can be easily magnetized by partial magnetization. (NEDO)

The V0 detector is two disks of counters in both sides of the interaction point.

CERN Multimedia

Grossiord, Jean-Yves

2006-01-01

The V0 detector is two disks of counters in both sides of the interaction point. Here is the V0C disk to be fixed on the front face of the muon spectrometer absorber. It is made of 48 scintillating elements coupled to two wavelength fibre layers which emit and guide the light up to connrctors arounda case made of Carbon fibre plates. The light going out of connectors is collected by an optical fibre bundle and transmitted at 3 metres to photo-multipliers which convert light to electrical signal. The elements are set in the case following 2 small rings of 8 counters and 2 large rings of 16 counters grouped two by two. 32 channels of detection distributed around the LHC beam pipe constitute thus the detector

Double Ring Antenna Design for MIMO Application in Mobile Terminals

DEFF Research Database (Denmark)

Zhao, Kun; Zhang, Shuai; Ying, Zhinong

2015-01-01

In this paper, We present a MIMO bezel antenna design composed by a seamless double metal ring structure. The MIMO antenna mainly operates in the loop mode and can cover the majority of globe cellular bands. Good efficiencies (>-4dB) and a low envelope correlation coefficient (<0.5) are achieved,...

Report of the eRHIC Ring-Ring Working Group

Energy Technology Data Exchange (ETDEWEB)

Aschenauer, E. C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Berg, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blaskiewicz, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brennan, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fedotov, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Litvinenko, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Montag, C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Palmer, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Parker, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Peggs, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ranjbar, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tepikian, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Willeke, F. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-10-13

This report evaluates the ring-ring option for eRHIC as a lower risk alternative to the linac-ring option. The reduced risk goes along with a reduced initial luminosity performance. However, a luminosity upgrade path is kept open. This upgrade path consists of two branches, with the ultimate upgrade being either a ring-ring or a linac-ring scheme. The linac-ring upgrade could be almost identical to the proposed linac-ring scheme, which is based on an ERL in the RHIC tunnel. This linac-ring version has been studied in great detail over the past ten years, and its significant risks are known. On the other hand, no detailed work on an ultimate performance ring-ring scenario has been performed yet, other than the development of a consistent parameter set. Pursuing the ring-ring upgrade path introduces high risks and requires significant design work that is beyond the scope of this report.

Axial magnetic field produced by axially and radially magnetized permanent rings

International Nuclear Information System (INIS)

Peng, Q.L.; McMurry, S.M.; Coey, J.M.D.

2004-01-01

Axial magnetic fields produced by axially and radially magnetized permanent magnet rings were studied. First, the axial magnetic field produced by a current loop is introduced, from which the axial field generated by an infinitely thin solenoid and by an infinitely thin current disk can be derived. Then the axial fields produced by axially and by radially magnetized permanent magnet rings can be obtained. An analytic formula for the axial fields produced by two axially magnetized rings is given. A permanent magnet with a high axial gradient field is fabricated, the measured results agree with the theoretical calculation very well. As an example, the axial periodic field produced by an arrangement of alternating axially and radially magnetized rings has been discussed

Short-time action electric generators to power physical devices

International Nuclear Information System (INIS)

Glebov, I.A.; Kasharskij, Eh.G.; Rutberg, F.G.; Khutoretskij, G.M.

1982-01-01

Requirements to be met by power-supply sources of the native electrophysical facilities have been analyzed and trends in designing foreign electric machine units of short-time action have been considered. Specifications of a generator, manufactured in the form of synchronous bipolar turbogenerator with an all-forged rotor with indirect air cooling of the rotor and stator windings are presented. Front parts of the stator winding are additionally fixed using glass-textolite rings, brackets and gaskets. A flywheel, manufactured in the form of all-forged steel cylinder is joined directly with the generator rotor by means of a half-coupling. An acceleration asynchronous engine with a phase rotor of 4 MW nominal capacity is located on the opposite side of the flywheel. The generator peak power is 242 MVxA; power factor = 0.9; energy transferred to the load 5per 1 pulse =00 MJ; the flywheel weight 81 t

First design for the optics of the decay ring for the beta-beams

International Nuclear Information System (INIS)

Chance, A.; Payet, J.

2006-03-01

The aim of the beta-beams is to produce pure electronic neutrino and anti-neutrino highly energetic beams, coming from beta radioactive disintegration decay of the 18 Ne 10+ and 6 He 2+ , directed to experiment situated in the Frejus tunnel. The high ion intensities are stored in a ring, until the ions decay. The losses due to the decay of the radioactive ions are compensated with regular injections. These should be done in presence of the circulating beam. The new ions are injected at a different energy from the stored beam energy, the design of the ring must enable this type of injection and accept the injected and stored beams. In this note, we will focus on the study of the design of such a ring at the first and second orders. We have reached the constraint on the dispersion in the injection section: a horizontal dispersion superior to 10 m with β x = 20 m. We have put sextupoles in the arcs to correct the chromaticity. In the same time, we have compensated the third order resonances to have a large enough dynamic aperture. So the decay ring accepts injected and stored beams. In a top-down approach, the high stored intensities impose to take into account the space charge effects. However, due to the merging, the beam blows up after each injection in the longitudinal space charge, which imposes to include a momentum collimation section in the decay ring

8-inch IBM floppy disk

CERN Multimedia

1971-01-01

The 8-inch floppy disk was a magnetic storage disk for the data introduced commercially by IBM in 1971. It was designed by an IBM team as an inexpensive way to load data into the IBM System / 370. Plus it was a read-only bare disk containing 80 KB of data. The first read-write version was introduced in 1972 by Memorex and could contain 175 KB on 50 tracks (with 8 sectors per track). Other improvements have led to various coatings and increased capacities. Finally, it was surpassed by the mini diskette of 5.25 inches introduced in 1976.

A double-superconducting axial bearing system for an energy storage flywheel model

Science.gov (United States)

Deng, Z.; Lin, Q.; Ma, G.; Zheng, J.; Zhang, Y.; Wang, S.; Wang, J.

2008-02-01

The bulk high temperature superconductors (HTSCs) with unique flux-pinning property have been applied to fabricate two superconducting axial bearings for an energy storage flywheel model. The two superconducting axial bearings are respectively fixed at two ends of the vertical rotational shaft, whose stator is composed of seven melt-textured YBa2Cu3O7-x (YBCO) bulks with diameter of 30 mm, height of 18 mm and rotor is made of three cylindrical axial-magnetized NdFeB permanent magnets (PM) by superposition with diameter of 63 mm, height of 27 mm. The experimental results show the total levitation and lateral force produced by the two superconducting bearings are enough to levitate and stabilize the 2.4 kg rotational shaft. When the two YBCO stators were both field cooled to the liquid nitrogen temperature at respective axial distances above or below the PM rotor, the shaft could be automatically levitated between the two stators without any contact. In the case of a driving motor, it can be stably rotated along the central axis besides the resonance frequency. This double-superconducting axial bearing system can be used to demonstrate the flux-pinning property of bulk HTSC for stable levitation and suspension and the principle of superconducting flywheel energy storage system to visitors.

Studies of Young, Star-forming Circumstellar Disks

Science.gov (United States)

Bae, Jaehan

2017-08-01

Disks of gas and dust around forming stars - circumstellar disks - last only a few million years. This is a very small fraction of the entire lifetime of Sun-like stars, several billion years. Nevertheless, by the time circumstellar disks dissipate stars complete building up their masses, giant planets finish accreting gas, and terrestrial bodies are nearly fully grown and ready for their final assembly to become planets. Understanding the evolution of circumstellar disks are thus crucial in many contexts. Using numerical simulations as the primary tool, my thesis has focused on the studies of various physical processes that can occur throughout the lifetime of circumstellar disks, from their formation to dispersal. Chapters 2, 3, and 4 emphasize the importance of early evolution, during which time a forming star-disk system obtains mass from its natal cloud: the infall phase. In Chapter 2 and 3, I have modeled episodic outbursts of accretion in protostellar systems resulting from disk instabilities - gravitational instability and magnetorotational instability. I showed that outbursts occur preferentially during the infall phase, because the mass addition provides more favorable conditions for gravitational instability to initiate the outburst cycle, and that forming stars build up a significant fraction of their masses through repeated short-lived, episodic outbursts. The infall phase can also be important for the formation of planets. Recent ALMA observations revealed sets of bright and dark rings in circumstellar disks of young, forming stars, potentially indicating early formation of planets. In Chapter 4, I showed that infall streams can create radial pressure bumps near the outer edge of the mass landing on the disk, from which vortices can form, collecting solid particles very efficiently to make initial seeds of planets. The next three chapters highlight the role of planets in setting the observational appearance and the evolution of circumstellar disks

HUNTING FOR PLANETS IN THE HL TAU DISK

Energy Technology Data Exchange (ETDEWEB)

Testi, L. [ESO, Karl Schwarzschild str. 2, D-85748 Garching bei Muenchen (Germany); Skemer, A.; Bailey, V.; Defrère, D.; Hinz, Ph.; Leisenring, J.; Vaz, A. [Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Henning, Th. [Max Planck Institute for Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Esposito, S. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze (Italy); Fontana, A. [INAF-Osservatorio Astronomico di Roma, Monte Porzio (Italy); Marconi, A. [Universitá degli Studi di Firenze, Dipartimento di Fisica e Astronomia, Firenze (Italy); Skrutskie, M. [University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Veillet, C., E-mail: ltesti@eso.org [LBT Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States)

2015-10-20

Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a gravitationally unstable disk. To test this scenario, we searched for young planets by means of direct imaging in the L′ band using the Large Binocular Telescope Interferometer mid-infrared camera. At the location of two prominent dips in the dust distribution at ∼70 AU (∼0.″5) from the central star, we reach a contrast level of ∼7.5 mag. We did not detect any point sources at the location of the rings. Using evolutionary models we derive upper limits of ∼10–15 M{sub Jup} at ≤0.5–1 Ma for the possible planets. With these sensitivity limits we should have been able to detect companions sufficiently massive to open full gaps in the disk. The structures detected at millimeter wavelengths could be gaps in the distributions of large grains on the disk midplane caused by planets not massive enough to fully open the gaps. Future ALMA observations of the molecular gas density profile and kinematics as well as higher contrast infrared observations may be able to provide a definitive answer.

HUNTING FOR PLANETS IN THE HL TAU DISK

International Nuclear Information System (INIS)

Testi, L.; Skemer, A.; Bailey, V.; Defrère, D.; Hinz, Ph.; Leisenring, J.; Vaz, A.; Henning, Th.; Esposito, S.; Fontana, A.; Marconi, A.; Skrutskie, M.; Veillet, C.

2015-01-01

Recent ALMA images of HL Tau show gaps in the dusty disk that may be caused by planetary bodies. Given the young age of this system, if confirmed, this finding would imply very short timescales for planet formation, probably in a gravitationally unstable disk. To test this scenario, we searched for young planets by means of direct imaging in the L′ band using the Large Binocular Telescope Interferometer mid-infrared camera. At the location of two prominent dips in the dust distribution at ∼70 AU (∼0.″5) from the central star, we reach a contrast level of ∼7.5 mag. We did not detect any point sources at the location of the rings. Using evolutionary models we derive upper limits of ∼10–15 M Jup at ≤0.5–1 Ma for the possible planets. With these sensitivity limits we should have been able to detect companions sufficiently massive to open full gaps in the disk. The structures detected at millimeter wavelengths could be gaps in the distributions of large grains on the disk midplane caused by planets not massive enough to fully open the gaps. Future ALMA observations of the molecular gas density profile and kinematics as well as higher contrast infrared observations may be able to provide a definitive answer

A Control Algorithm for Electric Vehicle Fast Charging Stations Equipped with Flywheel Energy Storage Systems

DEFF Research Database (Denmark)

Sun, Bo; Dragicevic, Tomislav; Freijedo Fernandez, Francisco Daniel

2016-01-01

This paper proposes a control strategy for plugin electric vehicle (PEV) fast charging station (FCS) equipped with a flywheel energy storage system (FESS). The main role of the FESS is not to compromise the predefined charging profile of PEV battery during the provision of a hysteresis-type active...

DETECTION OF SHARP SYMMETRIC FEATURES IN THE CIRCUMBINARY DISK AROUND AK Sco

International Nuclear Information System (INIS)

Janson, Markus; Asensio-Torres, Ruben; Thalmann, Christian; Meyer, Michael R.; Garufi, Antonio; Boccaletti, Anthony; Maire, Anne-Lise; Henning, Thomas; Pohl, Adriana; Zurlo, Alice; Marzari, Francesco; Carson, Joseph C.; Augereau, Jean-Charles; Desidera, Silvano

2016-01-01

The Search for Planets Orbiting Two Stars survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ∼13–40 AU range. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk

DETECTION OF SHARP SYMMETRIC FEATURES IN THE CIRCUMBINARY DISK AROUND AK Sco

Energy Technology Data Exchange (ETDEWEB)

Janson, Markus; Asensio-Torres, Ruben [Department of Astronomy, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm (Sweden); Thalmann, Christian; Meyer, Michael R.; Garufi, Antonio [Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland); Boccaletti, Anthony [LESIA, Observatoire de Paris—Meudon, CNRS, Université Pierre et Marie Curie, Université Paris Didierot, 5 Place Jules Janssen, F-92195 Meudon (France); Maire, Anne-Lise; Henning, Thomas; Pohl, Adriana [Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany); Zurlo, Alice [Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejercito 441, Santiago (Chile); Marzari, Francesco [Dipartimento di Fisica, University of Padova, Via Marzolo 8, I-35131 Padova (Italy); Carson, Joseph C. [Department of Physics and Astronomy, College of Charleston, 66 George Street, Charleston, SC 29424 (United States); Augereau, Jean-Charles [Université Grenoble Alpes, IPAG, F-38000 Grenoble (France); Desidera, Silvano [INAF—Osservatorio Astromonico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy)

2016-01-01

The Search for Planets Orbiting Two Stars survey aims to study the formation and distribution of planets in binary systems by detecting and characterizing circumbinary planets and their formation environments through direct imaging. With the SPHERE Extreme Adaptive Optics instrument, a good contrast can be achieved even at small (<300 mas) separations from bright stars, which enables studies of planets and disks in a separation range that was previously inaccessible. Here, we report the discovery of resolved scattered light emission from the circumbinary disk around the well-studied young double star AK Sco, at projected separations in the ∼13–40 AU range. The sharp morphology of the imaged feature is surprising, given the smooth appearance of the disk in its spectral energy distribution. We show that the observed morphology can be represented either as a highly eccentric ring around AK Sco, or as two separate spiral arms in the disk, wound in opposite directions. The relative merits of these interpretations are discussed, as well as whether these features may have been caused by one or several circumbinary planets interacting with the disk.

Design of a Weighted-Rotor Energy Harvester Based on Dynamic Analysis and Optimization of Circular Halbach Array Magnetic Disk

Directory of Open Access Journals (Sweden)

Yu-Jen Wang

2015-03-01

Full Text Available This paper proposes the design of a weighted-rotor energy harvester (WREH in which the oscillation is caused by the periodic change of the tangential component of gravity, to harvest kinetic energy from a rotating wheel. When a WREH is designed with a suitable characteristic length, the rotor’s natural frequency changes according to the wheel rotation speed and the rotor oscillates at a wide angle and high angular velocity to generate a large amount of power. The magnetic disk is designed according to an optimized circular Halbach array. The optimized circular Halbach array magnetic disk provides the largest induced EMF for different sector-angle ratios for the same magnetic disk volume. This study examined the output voltage and power by considering the constant and accelerating plate-rotation speeds, respectively. This paper discusses the effects of the angular acceleration speed of a rotating wheel corresponding to the dynamic behaviors of a weighted rotor. The average output power is 399 to 535 microwatts at plate-rotation speeds from 300 to 500 rpm, enabling the WREH to be a suitable power source for a tire-pressure monitoring system.

Design and implementation of a fiber optic link for a token ring local area network

OpenAIRE

Doran, Thomas J.

1992-01-01

Approved for public release; distribution is unlimited This thesis described the design and implementation of a fiber optic link for a token ring local area network (LAN). It features the use of fiber optic channels as the transmission medium between a computer system and a wiring concentrator to convert a physical ring design into a star-wired configuration. The LAN was controlled by the TMS380 LAN Adapter chipset, which provided all diagnostic and network management features to include...

AN ORIGIN OF MULTIPLE RING STRUCTURE AND HIDDEN PLANETS IN HL TAU: A UNIFIED PICTURE BY SECULAR GRAVITATIONAL INSTABILITY

International Nuclear Information System (INIS)

Takahashi, Sanemichi Z.; Inutsuka, Shu-ichiro

2016-01-01

Recent ALMA observation has revealed multiple ring structures formed in a protoplanetary disk around HL Tau. Prior to the ALMA observation of HL Tau, theoretical analysis of secular gravitational instability (GI) described a possible formation of multiple ring structures with separations of 13 au around a radius of 100 au in protoplanetary disks under certain conditions. In this article, we reanalyze the viability of secular GI by adopting the physical values inferred from the observations. We derive the radial distributions of the most unstable wavelength and the growth timescale of secular GI and verify that secular GI can form the ring structures observed in HL Tau. When a turbulent viscosity coefficient α remains small in the inner region of the disk, secular GI grows in the whole disk. Thus, the formation of planetary mass objects should occur first in the inner region as a result of gravitational fragmentation after the nonlinear growth of secular GI. In this case, the resulting objects are expected to create gaps at r  ∼ 10 au and ∼30 au. As a result, all ring structures in HL Tau can be created by secular GI. If this scenario is realized in HL Tau, the outer region corresponds to the earlier growth phase of the most unstable mode of secular GI, and the inner region corresponds to the outcome of the nonlinear growth of secular GI. Therefore, this interpretation suggests that we are possibly witnessing both the beginning and the end of planet formation in HL Tau.

AN ORIGIN OF MULTIPLE RING STRUCTURE AND HIDDEN PLANETS IN HL TAU: A UNIFIED PICTURE BY SECULAR GRAVITATIONAL INSTABILITY

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Sanemichi Z. [Astronomical Institute, Tohoku University, 6-3 Aoba, Aramaki-aza, Aoba-ku, Sendai, Miyagi (Japan); Inutsuka, Shu-ichiro, E-mail: sanemichi@astr.tohoku.ac.jp, E-mail: inutsuka@nagoya-u.jp [Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8602 (Japan)

2016-12-01

Recent ALMA observation has revealed multiple ring structures formed in a protoplanetary disk around HL Tau. Prior to the ALMA observation of HL Tau, theoretical analysis of secular gravitational instability (GI) described a possible formation of multiple ring structures with separations of 13 au around a radius of 100 au in protoplanetary disks under certain conditions. In this article, we reanalyze the viability of secular GI by adopting the physical values inferred from the observations. We derive the radial distributions of the most unstable wavelength and the growth timescale of secular GI and verify that secular GI can form the ring structures observed in HL Tau. When a turbulent viscosity coefficient α remains small in the inner region of the disk, secular GI grows in the whole disk. Thus, the formation of planetary mass objects should occur first in the inner region as a result of gravitational fragmentation after the nonlinear growth of secular GI. In this case, the resulting objects are expected to create gaps at r  ∼ 10 au and ∼30 au. As a result, all ring structures in HL Tau can be created by secular GI. If this scenario is realized in HL Tau, the outer region corresponds to the earlier growth phase of the most unstable mode of secular GI, and the inner region corresponds to the outcome of the nonlinear growth of secular GI. Therefore, this interpretation suggests that we are possibly witnessing both the beginning and the end of planet formation in HL Tau.

Design and performance analysis of delay insensitive multi-ring structures

DEFF Research Database (Denmark)

Sparsø, Jens; Staunstrup, Jørgen

1993-01-01

A set of simple design and performance analysis techniques that have been successfully used to design a number of nontrivial delay insensitive circuits is described. Examples are building blocks for digital filters and a vector multiplier using a serial-parallel multiply and accumulate algorithm....... The vector multiplier circuit has been laid out, submitted for fabrication and successfully tested. Throughout the analysis elements from this design are used to illustrate the design and performance analysis techniques. The design technique is based on a data flow approach using pipelines and rings...... that are composed into larger multiring structures by joining and forking of signals. By limiting to this class of structures, it is possible, even for complex designs, to analyze the performance and establish an understanding of the bottlenecks....

Intelligent multi-unit disk controller

International Nuclear Information System (INIS)

Poirot, Lucien

1982-01-01

This controller has been designed as a link between a 16 bits minicomputer and two types of disks units interface: the SMD interface and an equivalent to the DRI unit interface. Four units of each type can be handled by the controller. A bit slice microprocessor controls the interface with the disks units. The maximum exchange rate is 8 megabits per second. A CRC feature has been provided for error detection. A 16 bits microprocessor implements the interface to the computer, assuring head positioning, the management of bad tracks, as well as the supervision of each transfer. A internal buffer memory allows an asynchronous dialogue with the computer. The implementation of the controller makes easy the adaptation to disks units of various types, and though it has been initially intended for a minicomputer of the MITRA type, its microprocessor based design makes it fitted to any minicomputer. (author) [fr

Optimized design of the chopper disks and the neutron guide in a disk chopper neutron time-of-flight spectrometer

International Nuclear Information System (INIS)

Copley, J.R.D.

1990-01-01

We consider important aspects of the performance of a disk chopper neutron time-of-flight spectrometer. The intensity at the sample position, and the contributions of the choppers to the resolution of the instrument, are evaluated as a function of the widths of the slots in the chopper disks and the width of the neutron guide between the disks. We find that there is an optimum choice of the ratios of these widths and that this choice depends on a single parameter which, for elastic scattering, is a simple ratio of distances. When pairs of counter-rotating disks are employed, the widths of the slots can be modified by grossly changing the phase relationship between the members of a chopper pair. If the slot widths are changed, the width of the guide should also be altered in order to maintain the spectrometer in an optimized state. This change in the guide width may be effectively achieved using an arrangement of nested guides. Resolution and intensity calculations demonstrate the important gains which may be realized using this approach. (orig.)

GAP CLEARING BY PLANETS IN A COLLISIONAL DEBRIS DISK

Energy Technology Data Exchange (ETDEWEB)

Nesvold, Erika R. [Department of Physics, University of Maryland Baltimore County 1000 Hilltop Circle Baltimore, MD 21250 (United States); Kuchner, Marc J., E-mail: Erika.Nesvold@umbc.edu, E-mail: Marc.Kuchner@nasa.gov [NASA Goddard Space Flight Center Exoplanets and Stellar Astrophysics Laboratory, Code 667 Greenbelt, MD 21230 (United States)

2015-01-10

We apply our 3D debris disk model, SMACK, to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (α = 2/7). We find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index α of the power law depends on the age of the system t relative to the collisional timescale t {sub coll} of the disk by α = 0.32(t/t {sub coll}){sup –0.04}, with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion resonances near the chaotic zone. We investigate the effects of the initial eccentricity distribution of the disk particles and find a negligible effect on the gap size at Jovian planet masses, since collisions tend to erase memory of the initial particle eccentricity distributions. Finally, we find that the presence of Trojan analogs is a potentially powerful diagnostic of planets in the mass range ∼1-10 M {sub Jup}. We apply our model to place new upper limits on planets around Fomalhaut, HR 4796 A, HD 202628, HD 181327, and β Pictoris.

GAP CLEARING BY PLANETS IN A COLLISIONAL DEBRIS DISK

International Nuclear Information System (INIS)

Nesvold, Erika R.; Kuchner, Marc J.

2015-01-01

We apply our 3D debris disk model, SMACK, to simulate a planet on a circular orbit near a ring of planetesimals that are experiencing destructive collisions. Previous simulations of a planet opening a gap in a collisionless debris disk have found that the width of the gap scales as the planet mass to the 2/7th power (α = 2/7). We find that gap sizes in a collisional disk still obey a power law scaling with planet mass, but that the index α of the power law depends on the age of the system t relative to the collisional timescale t coll of the disk by α = 0.32(t/t coll ) –0.04 , with inferred planet masses up to five times smaller than those predicted by the classical gap law. The increased gap sizes likely stem from the interaction between collisions and the mean motion resonances near the chaotic zone. We investigate the effects of the initial eccentricity distribution of the disk particles and find a negligible effect on the gap size at Jovian planet masses, since collisions tend to erase memory of the initial particle eccentricity distributions. Finally, we find that the presence of Trojan analogs is a potentially powerful diagnostic of planets in the mass range ∼1-10 M Jup . We apply our model to place new upper limits on planets around Fomalhaut, HR 4796 A, HD 202628, HD 181327, and β Pictoris

Evaluation of Amount of Blood in Dry Blood Spots: Ring-Disk Electrode Conductometry.

Science.gov (United States)

Kadjo, Akinde F; Stamos, Brian N; Shelor, C Phillip; Berg, Jordan M; Blount, Benjamin C; Dasgupta, Purnendu K

2016-06-21

A fixed area punch in dried blood spot (DBS) analysis is assumed to contain a fixed amount of blood, but the amount actually depends on a number of factors. The presently preferred approach is to normalize the measurement with respect to the sodium level, measured by atomic spectrometry. Instead of sodium levels, we propose electrical conductivity of the extract as an equivalent nondestructive measure. A dip-type small diameter ring-disk electrode (RDE) is ideal for very small volumes. However, the conductance (G) measured by an RDE depends on the depth (D) of the liquid below the probe. There is no established way of computing the specific conductance (σ) of the solution from G. Using a COMSOL Multiphysics model, we were able to obtain excellent agreement between the measured and the model predicted conductance as a function of D. Using simulations over a large range of dimensions, we provide a spreadsheet-based calculator where the RDE dimensions are the input parameters and the procedure determines the 99% of the infinite depth conductance (G99) and the depth D99 at which this is reached. For typical small diameter probes (outer electrode diameter ∼ <2 mm), D99 is small enough for dip-type measurements in extract volumes of ∼100 μL. We demonstrate the use of such probes with DBS extracts. In a small group of 12 volunteers (age 20-66), the specific conductance of 100 μL aqueous extracts of 2 μL of spotted blood showed a variance of 17.9%. For a given subject, methanol extracts of DBS spots nominally containing 8 and 4 μL of blood differed by a factor of 1.8-1.9 in the chromatographically determined values of sulfate and chloride (a minor and major constituent, respectively). The values normalized with respect to the conductance of the extracts differed by ∼1%. For serum associated analytes, normalization of the analyte value by the extract conductance can thus greatly reduce errors from variations in the spotted blood volume/unit area.

Radiation safety design for SSRL storage ring

Energy Technology Data Exchange (ETDEWEB)

Khater, Hesham [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)]. E-mail: khater1@llnl.gov; Liu, James [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Fasso, Alberto [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Prinz, Alyssa [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Rokni, Sayed [Radiation Protection Department, Stanford Linear Accelerator Center (SLAC), 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

2006-12-15

In 2003, the Stanford Synchrotron Radiation Laboratory (SSRL) had upgraded its storage ring to a 3rd generation storage ring (SPEAR3). SPEAR3 is deigned to operate at 500-mA stored beam current and 3-GeV energy. The 234-m circumference SPEAR3 ring utilizes 60-cm-thick concrete lateral walls, 30-cm-thick concrete roof, as well as 60- or 90-cm-thick concrete ratchet walls. A total of 3.5x10{sup 15}e{sup -}/y will be injected into the ring with an injection power of 4W and an injection efficiency of 75%. Normal beam losses occur due to both injection and stored beam operations in the total of 20 low loss as well as 3 high loss limiting apertures. During the 6-min injection period, an instantaneous power loss of 0.05W occurs at each low loss aperture. When averaged over the operational year, the loss of both the injection and the stored beams is equivalent to an average loss of 2mW at each low loss aperture. On the other hand, the average losses in the high loss apertures are 16mW for the injection septum, 47mW for the beam abort dump, and 13mW for the ring stoppers. The shielding requirements for losses in the new ring were based on a generic approach that used both FLUKA Monte Carlo particle generation and transport code and empirical computer codes and formulae.

Circumstellar disks around binary stars in Taurus

International Nuclear Information System (INIS)

Akeson, R. L.; Jensen, E. L. N.

2014-01-01

We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10 –4 M ☉ . We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F mm ∝M ∗ 1.5--2.0 to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

Homogeneous Analysis of the Dust Morphology of Transition Disks Observed with ALMA: Investigating Dust Trapping and the Origin of the Cavities

Science.gov (United States)

Pinilla, P.; Tazzari, M.; Pascucci, I.; Youdin, A. N.; Garufi, A.; Manara, C. F.; Testi, L.; van der Plas, G.; Barenfeld, S. A.; Canovas, H.; Cox, E. G.; Hendler, N. P.; Pérez, L. M.; van der Marel, N.

2018-05-01

We analyze the dust morphology of 29 transition disks (TDs) observed with Atacama Large (sub-)Millimeter Array (ALMA) at (sub-)millimeter emission. We perform the analysis in the visibility plane to characterize the total flux, cavity size, and shape of the ring-like structure. First, we found that the M dust–M ⋆ relation is much flatter for TDs than the observed trends from samples of class II sources in different star-forming regions. This relation demonstrates that cavities open in high (dust) mass disks, independent of the stellar mass. The flatness of this relation contradicts the idea that TDs are a more evolved set of disks. Two potential reasons (not mutually exclusive) may explain this flat relation: the emission is optically thick or/and millimeter-sized particles are trapped in a pressure bump. Second, we discuss our results of the cavity size and ring width in the context of different physical processes for cavity formation. Photoevaporation is an unlikely leading mechanism for the origin of the cavity of any of the targets in the sample. Embedded giant planets or dead zones remain as potential explanations. Although both models predict correlations between the cavity size and the ring shape for different stellar and disk properties, we demonstrate that with the current resolution of the observations, it is difficult to obtain these correlations. Future observations with higher angular resolution observations of TDs with ALMA will help discern between different potential origins of cavities in TDs.

Design of 8-ft-Diameter Barrel Test Article Attachment Rings for Shell Buckling Knockdown Factor Project

Science.gov (United States)

Lovejoy, Andrew E.; Hilburger, Mark W.

2010-01-01

The Shell Buckling Knockdown Factor (SBKF) project includes the testing of sub-scale cylinders to validate new shell buckling knockdown factors for use in the design of the Ares-I and Ares-V launch vehicles. Test article cylinders represent various barrel segments of the Ares-I and Ares-V vehicles, and also include checkout test articles. Testing will be conducted at Marshall Space Flight Center (MSFC) for test articles having an eight-foot diameter outer mold line (OML) and having lengths that range from three to ten feet long. Both ends of the test articles will be connected to the test apparatus using attachment rings. Three multiple-piece and one single-piece design for the attachment rings were developed and analyzed. The single-piece design was chosen and will be fabricated from either steel or aluminum (Al) depending on the required safety factors (SF) for test hardware. This report summarizes the design and analysis of these attachment ring concepts.

Simulation of the fuel consumption benefits of various transmission arrangements and control strategies within a flywheel based mechanical hybrid system

Energy Technology Data Exchange (ETDEWEB)

Body, William; Brockbank, Chris [Torotrak (Development) Ltd. (United Kingdom)

2009-07-01

Flywheel based mechanical hybrid technology is being developed for both motorsport and mainstream automotive applications. One particular road car application project, part funded by the UK Government Technology Strategy Board, is being led by Jaguar Land Rover, managed by Prodrive and using advanced technology from Flybrid Systems, Ford, Ricardo. Torotrak and Xtrac. During the two year programme, the group will develop the new technology and build a demonstrator vehicle equipped with the system. The mechanical system recovers kinetic energy from the vehicle during braking to a high speed rotating flywheel via a variable drive system. When compared to an electric motor / battery arrangement, the mechanical hybrid system offers benefits in cost, weight, package, efficiency and ultimately vehicle fuel consumption. As part of the development and optimisation process in order to specify the road car system, all aspects of the mechanical hybrid system are under investigation by the group. Alongside the required quantity of energy storage and the rates of energy recovery and reapplication, a number of different physical architectures for the system are being analysed. The Torotrak full-toroidal traction drive has been assigned as the variable drive element of the mechanical hybrid system. Multiple configuration options are available including direct drive, epicyclic shunted, range extended CVT and epicyclic shunted IVT arrangements. In addition, the flywheel and variable drive system can be connected to the powertrain in a variety of different locations, from the engine through the powertrain to the wheels. This paper describes the simulation of the mechanical hybrid system with particular focus on the impact on the fuel consumption benefit, over multiple drive cycles, of the variable drive configuration, the location of the variable drive and flywheel system and the control strategy options. (orig.)

Planetary Rings: a Brief History of Observation and Theory

Science.gov (United States)

Nicholson, P. D.

2000-05-01

Over several centuries, and extending down to today, the ring systems encircling Saturn and the other jovian planets have provided an endless source of speculation and theorizing for astronomers, theologians, and physicists. In the past two decades they have also become a testing ground for dynamical models of more distant astrophysical disks, such as those which surround protostars and even the stellar disks of spiral galaxies. I will review some of the early theories, and their sometimes rude confrontation with observational data, starting with Christiaan Huygens and touching on seminal contributions by Laplace, Bessel, Maxwell, Barnard, Russell (of H-R diagram fame) and Jeffreys. In the modern era, observations at infrared and radio wavelengths have revealed Saturn's rings to be composed of large chunks of almost pure water ice, and to have a vertical thickness measured in tens of meters. A renaissance in planetary rings studies occurred in the period 1977--1981, first with the discoveries of the narrow, dark and non-circular rings of Uranus and the tenuous jovian ring system, and capped off by the spectacular images returned during the twin Voyager flybys of Saturn. Along with the completely unsuspected wealth of detail these observations revealed came an unwelcome problem: are the rings ancient or are we privileged to live at a special time in history? The answer to this still-vexing question may lie in the complex gravitational interactions recent studies have revealed between the rings themselves and their retinues of attendant satellites. Between the four known ring systems, we see elegant examples of Lindblad and corotation resonances (first invoked in the galactic context), electromagnetic resonances, many-armed spiral density waves and bending waves, narrow ringlets which exhibit internal modes due to a collective instability, sharp-edged gaps maintained via tidal torques from embedded moonlets, and tenuous dust belts created by meteoroid impact onto

Report on results 1998. Research and development on high-temperature superconducting flywheel power storage (investigation on system introduction); 1998 nendo seika hokokusho. Koon chodendo flywheel denryoku chozo kenkyu kaihatsu (system donyu chosa)

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-05-01

In introducing high-temperature superconducting flywheel power storage equipment to an electrical power system, adaptability is examined and evaluated concerning secondary effect that can be expected while a load leveling function is maintained. The 1998 plan is such that the functions and usages other than the load leveling are put in order for such equipment, and that the effect/adaptability in the case of the introduction into the power system is evaluated by means of simulation and literature studies. The high-temperature superconducting flywheel power storage equipment may be used for such purposes as energy adjustment for a short time, system voltage adjustment and emergency power source, other than the load leveling, on the basis of the characteristics that enable high speed control of active/reactive power and storage/release of energy. Enumerated, as the effects obtainable in introducing these uses into the power system, are enhancement in system stability, improvement in voltage stability, improvement in instantaneous voltage drop, maintenance of system frequency, compensation of fluctuating load, countermeasures against power outrage, and output leveling of intermittent power sources, and these effects were examined. (NEDO)

Secular Evolution in Disk Galaxies

Science.gov (United States)

Kormendy, John

2013-10-01

Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via the evolution processes that are available to them. They do this by spreading -- the inner parts shrink while the outer parts expand -- provided that some physical process efficiently transports energy or angular momentum outward. The reason is that self-gravitating systems have negative specific heats. As a result, the evolution of stars, star clusters, protostellar and protoplanetary disks, black hole accretion disks and galaxy disks are fundamentally similar. How evolution proceeds then depends on the evolution processes that are available to each kind of self-gravitating system. These processes and their consequences for galaxy disks are the subjects of my lectures and of this Canary Islands Winter School. I begin with a review of the formation, growth and death of bars. Then I review the slow (`secular') rearrangement of energy, angular momentum, and mass that results from interactions between stars or gas clouds and collective phenomena such as bars, oval disks, spiral structure and triaxial dark haloes. The `existence-proof' phase of this work is largely over: we have a good heuristic understanding of how nonaxisymmetric structures rearrange disk gas into outer rings, inner rings and stuff dumped onto the centre. The results of simulations correspond closely to the morphology of barred and oval galaxies. Gas that is transported to small radii reaches high densities. Observations confirm that many barred and oval galaxies have dense central concentrations of gas and star formation. The result is to grow, on timescales of a few Gyr, dense central components that are frequently mistaken for classical (elliptical-galaxy-like) bulges but that were grown slowly out of the disk (not made rapidly by major mergers). The resulting picture of secular galaxy evolution accounts for the richness observed in galaxy structure. We can distinguish between classical and pseudo

SUBMILLIMETER POLARIZATION OBSERVATION OF THE PROTOPLANETARY DISK AROUND HD 142527

Energy Technology Data Exchange (ETDEWEB)

Kataoka, Akimasa; Dullemond, Cornelis P.; Pohl, Adriana [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Tsukagoshi, Takashi; Momose, Munetake [College of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512 (Japan); Nagai, Hiroshi [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Muto, Takayuki [Division of Liberal Arts, Kogakuin University, 1-24-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 163-8677 (Japan); Fukagawa, Misato [Division of Particle and Astrophysical Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan); Shibai, Hiroshi [Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Hanawa, Tomoyuki [Center for Frontier Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522 (Japan); Murakawa, Koji, E-mail: kataoka@uni-heidelberg.de [College of General Education, Osaka Sangyo University, 3-1-1, Nakagaito, Daito, Osaka 574-8530 (Japan)

2016-11-10

We present the polarization observations toward the circumstellar disk around HD 142527 by using Atacama Large Millimeter/submillimeter Array at the frequency of 343 GHz. The beam size is 0.″51 × 0.″44, which corresponds to the spatial resolution of ∼71 × 62 au. The polarized intensity displays a ring-like structure with a peak located on the east side with a polarization fraction of P = 3.26 ± 0.02%, which is different from the peak of the continuum emission from the northeast region. The polarized intensity is significantly weaker at the peak of the continuum where P = 0.220 ± 0.010%. The polarization vectors are in the radial direction in the main ring of the polarized intensity, while there are two regions outside at the northwest and northeast areas where the vectors are in the azimuthal direction. If the polarization vectors represent the magnetic field morphology, the polarization vectors indicate the toroidal magnetic field configuration on the main ring and the poloidal fields outside. On the other hand, the flip of the polarization vectors is predicted by the self-scattering of thermal dust emission due to the change of the direction of thermal radiation flux. Therefore, we conclude that self-scattering of thermal dust emission plays a major role in producing polarization at millimeter wavelengths in this protoplanetary disk. Also, this puts a constraint on the maximum grain size to be approximately 150 μ m if we assume compact spherical dust grains.

Plate heat exchanger - inertia flywheel performance in loss of flow transient

International Nuclear Information System (INIS)

Abou-El-Maaty, Talal; Abd-El-Hady, Amr

2009-01-01

One of the most versatile types of heat exchangers used is the plate heat exchanger. It has principal advantages over other heat exchangers in that plates can be added and/or removed easily in order to change the area available for heat transfer and therefore its overall performance. The cooling systems of Egypt's second research reactor (ETRR 2) use this type of heat exchanger for cooling purposes in its primary core cooling and pool cooling systems. In addition to the change in the number of heat exchanger cooling channels, the effect of changing the amount of mass flow rate on the heat exchanger performance is an important issues in this study. The inertia flywheel mounted on the primary core cooling system pump with the plate heat exchanger plays an important role in the case of loss of flow transients. The PARET code is used to simulate the effect of loss of flow transients on the reactor core. Hence, the core outlet temperature with the pump-flywheel flow coast down is fed into the plate heat exchanger model developed to estimate the total energy transferred to the cooling tower, the primary side heat exchanger temperature variation, the transmitted heat exchanger power, and the heat exchanger effectiveness. In addition, the pressure drop in both, the primary side and secondary side of the plate heat exchanger is calculated in all simulated transients because their values have limits beyond which the heat exchanger is useless. (orig.)

Polarization Insensitivity in Double-Split Ring and Triple-Split Ring Terahertz Resonators

International Nuclear Information System (INIS)

Wu Qian-Nan; Lan Feng; Tang Xiao-Pin; Yang Zi-Qiang

2015-01-01

A modified double-split ring resonator and a modified triple-split ring resonator, which offer polarization-insensitive performance, are investigated, designed and fabricated. By displacing the two gaps of the conventional double-split ring resonator away from the center, the second resonant frequency for the 0° polarized wave and the resonant frequency for the 90° polarized wave become increasingly close to each other until they are finally identical. Theoretical and experimental results show that the modified double-split ring resonator and the modified triple-split ring resonator are insensitive to different polarized waves and show strong resonant frequency dips near 433 and 444 GHz, respectively. The results of this work suggest new opportunities for the investigation and design of polarization-dependent terahertz devices based on split ring resonators. (paper)

Damping of Low Frequency Oscillation in Power System using Robust Control of Superconductor Flywheel Energy Storage System

International Nuclear Information System (INIS)

Lee, Jung Pil; Kim, Han Gun

2012-01-01

In this paper, the robust superconductor flywheel energy storage system(SFESS) controller using H control theory was designed to damp low frequency oscillation of power system. The main advantage of the controller is that uncertainties of power system can be included at the stage of controller design. Both disturbance attenuation and robust stability for the power system were treated simultaneously by using mixed sensitivity problem. The robust stability and the performance for uncertainties of power system were represented by frequency weighted transfer function. To verify control performance of proposed SFESS controller using control, the closed loop eigenvalue and the damping ratio in dominant oscillation mode of power system were analyzed and nonlinear simulation for one-machine infinite bus system was performed under disturbance for various operating conditions. The results showed that the proposed SFESS controller was more robust than conventional power system stabilizer (PSS).

The PEP-II Project: Low-Energy Ring Design and Project Status

International Nuclear Information System (INIS)

Zisman, Michael S.

2006-01-01

We describe the present status of the PEP-II project. The project comprises four major systems: Injector, High-Energy Ring (HER), Low-Energy Ring (LER), and Interaction Region (IR). We focus in detail on the design of the LER, as its parameters and requirements are most closely related to those required for the Beijing Tau-Charm Factory rings. The PEP-II LER is a high-current, 3.1-GeV positron ring mounted above the 9-GeV HER. The LER uses a wiggler located in one of its six straight sections to provide emittance control and additional damping. We describe the rather complicated IR, which must transport the LER beam into the plane of the HER, focus it to a common beam size, and separate the beams after the head-on collisions. Both permanent magnet and conventional electromagnets are used in this area. The LER lattice has now adopted a simplified non-interleaved sextupole correction scheme that has reduced the required number of sextupoles substantially. We describe the LER vacuum system, one of the most challenging subsystems in PEP-II. It employs several technologies. In the arcs, aluminum extrusions and titanium sublimation pumps are employed; the straight sections use stainless steel chambers with lumped ion pumps. In the wiggler area, an extended copper photon dump with nonevaporable getter (NEG) pumps is employed to handle the very large synchrotron radiation power. The design of the room-temperature RF system, the bunch-by-bunch longitudinal and transverse feedback systems, and some of the special diagnostics will be described briefly. The PEP-II project remains on schedule to begin commissioning of the HER in April 1997, followed by the LER a year later

MIGRATION OF A MOONLET IN A RING OF SOLID PARTICLES: THEORY AND APPLICATION TO SATURN'S PROPELLERS

International Nuclear Information System (INIS)

Crida, Aurelien; Papaloizou, John C. B.; Rein, Hanno; Charnoz, Sebastien; Salmon, Julien

2010-01-01

Hundred-meter-sized objects have been identified by the Cassini spacecraft in Saturn's A ring through the so-called propeller features they create in the ring. These moonlets should migrate due to their gravitational interaction with the ring; in fact, some orbital variations have been detected. The standard theory of type I migration of planets in protoplanetary disks cannot be applied to the ring system as it is pressureless. Thus, we compute the differential torque felt by a moonlet embedded in a two-dimensional disk of solid particles, with a flat surface density profile, both analytically and numerically. We find that the corresponding migration rate is too small to explain the observed variations of the propeller's orbit in Saturn's A ring. However, local density fluctuations (due to gravity wakes in the marginally gravitationally stable A ring) may exert a stochastic torque on a moonlet. Our simulations show that this torque can be large enough to account for the observations depending on the parameters of the rings. We find that on timescales of several years the migration of propellers is likely to be dominated by stochastic effects (while the former, non-stochastic migration dominates after ∼10 4 -10 5 years). In that case, the migration rates provided by observations so far suggest that the surface density of the A ring should be on the order of 700 kg m -2 . The age of the propellers should not exceed 1-100 million years depending on the dominant migration regime.

EVOLUTION OF A RING AROUND THE PLUTO–CHARON BINARY

Energy Technology Data Exchange (ETDEWEB)

Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 S 1400 E, Rm 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 (United States)

2015-08-10

We consider the formation of satellites around the Pluto–Charon binary. An early collision between the two partners likely produced the binary and a narrow ring of debris, out of which arose the moons Styx, Nix, Kerberos, and Hydra. How the satellites emerged from the compact ring is uncertain. Here we show that a particle ring spreads from physical collisions and collective gravitational scattering, similar to migration. Around a binary, these processes take place in the reference frames of “most circular” orbits, akin to circular ones in a Keplerian potential. Ring particles damp to these orbits and avoid destructive collisions. Damping and diffusion also help particles survive dynamical instabilities driven by resonances with the binary. In some situations, particles become trapped near resonances that sweep outward with the tidal evolution of the Pluto–Charon binary. With simple models and numerical experiments, we show how the Pluto–Charon impact ring may have expanded into a broad disk, out of which grew the circumbinary moons. In some scenarios, the ring can spread well beyond the orbit of Hydra, the most distant moon, to form a handful of smaller satellites. If these small moons exist, New Horizons will find them.

Optimality based repetitive controller design for track-following servo system of optical disk drives.

Science.gov (United States)

Chen, Wentao; Zhang, Weidong

2009-10-01

In an optical disk drive servo system, to attenuate the external periodic disturbances induced by inevitable disk eccentricity, repetitive control has been used successfully. The performance of a repetitive controller greatly depends on the bandwidth of the low-pass filter included in the repetitive controller. However, owing to the plant uncertainty and system stability, it is difficult to maximize the bandwidth of the low-pass filter. In this paper, we propose an optimality based repetitive controller design method for the track-following servo system with norm-bounded uncertainties. By embedding a lead compensator in the repetitive controller, both the system gain at periodic signal's harmonics and the bandwidth of the low-pass filter are greatly increased. The optimal values of the repetitive controller's parameters are obtained by solving two optimization problems. Simulation and experimental results are provided to illustrate the effectiveness of the proposed method.

Sensorless Control of Permanent Magnet Machine for NASA Flywheel Technology Development

Science.gov (United States)

Kenny, Barbara H.; Kascak, Peter E.

2002-01-01

This paper describes the position sensorless algorithms presently used in the motor control for the NASA "in-house" development work of the flywheel energy storage system. At zero and low speeds a signal injection technique, the self-sensing method, is used to determine rotor position. At higher speeds, an open loop estimate of the back EMF of the machine is made to determine the rotor position. At start up, the rotor is set to a known position by commanding dc into one of the phase windings. Experimental results up to 52,000 rpm are presented.

Preliminary Design Study of a Pre-booster Damping Ring for the FCC e+e− Injector

CERN Document Server

Etisken, O; Papaphilippou, Y

2017-01-01

The aim of the FCC e+e− lepton collider is to collide particles in the energy range 40–175 GeV. The FCC e+e− injector complex needs to produce and transport high-intensity e+e− beams at a fast repetition rate of about 0.1 Hz to top up the collider at its collision energy. A basic parameter set exists for all collider energies, assuming a 10 GeV linac operating with a large number of bunches accumulating in the existing SPS, which serves as pre-accelerator and damping ring before the bunches are transferred to the high-energy booster. The purpose of this study is to provide the conceptual design of an alternative damping and accelerator ring, replacing the SPS in the current scheme. This ring will have an injection energy of around 6 GeV and an extraction energy of around 20 GeV. Apart from establishing the basic ring parameters, the final study will include the optics design and layout, and single particle linear and non-linear dynamics optimization, including magnetic and alignment error tolerances. ...

Interstellar Explorer Observations of the Solar System's Debris Disks

Science.gov (United States)

Lisse, C. M.; McNutt, R. L., Jr.; Brandt, P. C.

2017-12-01

Planetesimal belts and debris disks full of dust are known as the "signposts of planet formation" in exosystems. The overall brightness of a disk provides information on the amount of sourcing planetesimal material, while asymmetries in the shape of the disk can be used to search for perturbing planets. The solar system is known to house two such belts, the Asteroid belt and the Kuiper Belt; and at least one debris cloud, the Zodiacal Cloud, sourced by planetisimal collisions and Kuiper Belt comet evaporative sublimation. However these are poorly understood in toto because we live inside of them. E.g., while we know of the two planetesimal belt systems, it is not clear how much, if any, dust is produced from the Kuiper belt since the near-Sun comet contributions dominate near-Earth space. Understanding how much dust is produced in the Kuiper belt would give us a much better idea of the total number of bodies in the belt, especially the smallest ones, and their dynamical collisional state. Even for the close in Zodiacal cloud, questions remain concerning its overall shape and orientation with respect to the ecliptic and invariable planes of the solar system - they aren't explainable from the perturbations caused by the known planets alone. In this paper we explore the possibilities of using an Interstellar Explorer telescope placed at 200 AU from the sun to observe the brightness, shape, and extent of the solar system's debris disk(s). We should be able to measure the entire extent of the inner, near-earth zodiacal cloud; whether it connects smoothly into an outer cloud, or if there is a second outer cloud sourced by the Kuiper belt and isolated by the outer planets, as predicted by Stark & Kuchner (2009, 2010) and Poppe et al. (2012, 2016; Figure 1). VISNIR imagery will inform about the dust cloud's density, while MIR cameras will provide thermal imaging photometry related to the cloud's dust particle size and composition. Observing at high phase angle by looking

Design and implementation of reliability evaluation of SAS hard disk based on RAID card

Science.gov (United States)

Ren, Shaohua; Han, Sen

2015-10-01

Because of the huge advantage of RAID technology in storage, it has been widely used. However, the question associated with this technology is that the hard disk based on the RAID card can not be queried by Operating System. Therefore how to read the self-information and log data of hard disk has been a problem, while this data is necessary for reliability test of hard disk. In traditional way, this information can be read just suitable for SATA hard disk, but not for SAS hard disk. In this paper, we provide a method by using LSI RAID card's Application Program Interface, communicating with RAID card and analyzing the feedback data to solve the problem. Then we will get the necessary information to assess the SAS hard disk.

FORMATION OF CENTAURS’ RINGS THROUGH THEIR PARTIAL TIDAL DISRUPTION DURING PLANETARY ENCOUNTERS

Energy Technology Data Exchange (ETDEWEB)

Hyodo, Ryuki; Charnoz, Sébastien [Institut de Physique du Globe, F-75005 Paris, France (France); Genda, Hidenori [Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ohtsuki, Keiji [Department of Planetology, Kobe University, Kobe 657-8501 (Japan)

2016-09-01

Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20−50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3−6 km s{sup −1} and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

FORMATION OF CENTAURS’ RINGS THROUGH THEIR PARTIAL TIDAL DISRUPTION DURING PLANETARY ENCOUNTERS

International Nuclear Information System (INIS)

Hyodo, Ryuki; Charnoz, Sébastien; Genda, Hidenori; Ohtsuki, Keiji

2016-01-01

Centaurs are minor planets orbiting between Jupiter and Neptune that have or had crossing orbits with one or more giant planets. Recent observations and reinterpretation of previous observations have revealed the existence of ring systems around 10199 Chariklo and 2060 Chiron. However, the origin of the ring systems around such a minor planet is still an open question. Here, we propose that the tidal disruption of a differentiated object that experiences a close encounter with a giant planet could naturally form diverse ring–satellite systems around the Centaurs. During the close encounter, the icy mantle of the passing object is preferentially ripped off by the planet's tidal force and the debris is distributed mostly within the Roche limit of the largest remnant body. Assuming the existence of a 20−50 wt% silicate core below the icy mantle, a disk of particles is formed when the objects pass within 0.4–0.8 of the planet's Roche limit with the relative velocity at infinity 3−6 km s"−"1 and 8 hr initial spin period of the body. The resultant ring mass is 0.1%–10% of the central object's mass. Such particle disks are expected to spread radially, and materials spreading beyond the Roche limit would accrete into satellites. Our numerical results suggest that ring formation would be a natural outcome of such extreme close encounters, and Centaurs can naturally have such ring systems because they cross the orbits of the giant planets.

Design and development of a bipolar power supply for APS storage ring correctors

International Nuclear Information System (INIS)

Kang, Y.G.

1993-01-01

The Advanced Photon Source (APS) requires a number of correction magnets. Basically, two different types of bipolar power supplies (BPS) will be used for all the correction magnets. One requires dc correction only, and the other requires dc and ac correction. For the storage ring horizontal/vertical (H/V) correctors, the BPS should be able to supply dc and ac current. This paper describes the design aspects and considerations for a bipolar power supply for the APS storage ring H/V correctors

The physics design of the Australian synchrotron storage ring

International Nuclear Information System (INIS)

Boldeman, J.W.; Einfeld, D.

2004-01-01

This paper describes the physics design of the Australian Synchrotron Storage Ring--Boomerang, which is currently under construction on a site adjacent to Monash University in Melbourne, Victoria. It also includes brief historical notes on the development of the proposal, some background material on the Australian synchrotron research community and preliminary information on possible research programs on the new facility. The facility itself is now in the early stages of construction under the leadership of Seaborne and Jackson

A CLOSER LOOK AT THE LkCa 15 PROTOPLANETARY DISK

International Nuclear Information System (INIS)

Andrews, Sean M.; Rosenfeld, Katherine A.; Wilner, David J.; Bremer, Michael

2011-01-01

We present 870 μm observations of dust continuum emission from the LkCa 15 protoplanetary disk at high angular resolution (with a characteristic scale of 0.''25 = 35 AU), obtained with the IRAM Plateau de Bure interferometer and supplemented by slightly lower resolution observations from the Submillimeter Array. We fit these data with simple morphological models to characterize the spectacular ring-like emission structure of this disk. Our analysis indicates that a small amount of 870 μm dust emission (∼5 mJy) originates inside a large (40-50 AU radius) low optical depth cavity. This result can be interpreted either in the context of an abrupt decrease by a factor of ∼5 in the radial distribution of millimeter-sized dust grains or as indirect evidence for a gap in the disk, in agreement with previous inferences from the unresolved infrared spectrum and scattered light images. A preliminary model focused on the latter possibility suggests the presence of a low-mass (planetary) companion, having properties commensurate with those inferred from the recent discovery of LkCa 15b.

Design of Experiments Relevant to Accreting Stream-Disk Impact in Interacting Binaries

Science.gov (United States)

Krauland, Christine; Drake, R. P.; Kuranz, C. C.; Grosskopf, M. J.; Young, R.; Plewa, T.

2010-05-01

In many Cataclysmic Binary systems, mass transfer via Roche lobe overflow onto an accretion disk occurs. This produces a hot spot from the heating created by the supersonic impact of the infalling flow with the rotating accretion disk, which can produce a radiative reverse shock in the infalling flow. This collision region has many ambiguities as a radiation hydrodynamic system. Depending upon conditions, it has been argued (Armitgae & Livio, ApJ 493, 898) that the shocked region may be optically thin, thick, or intermediate, which has the potential to significantly alter its structure and emissions. Laboratory experiments have yet to produce colliding flows that create a radiative reverse shock or to produce obliquely incident colliding flows, both of which are aspects of these Binary systems. We have undertaken the design of such an experiment, aimed at the Omega-60 laser facility. The design elements include the production of postshock flows within a dense material layer or ejecta flows by release of material from a shocked layer. Obtaining a radiative reverse shock in the laboratory requires producing a sufficiently fast flow (> 100 km/s) within a material whose opacity is large enough to produce energetically significant emission from experimentally achievable layers. In this poster we will discuss the astrophysical context, the experimental design work we have done, and the challenges of implementing and diagnosing an actual experiment. This work is funded by the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, by the National Laser User Facility Program in NNSA-DS and by the Predictive Sciences Academic Alliances Program in NNSA-ASC. The corresponding grant numbers are DE-FG52-09NA29548, DE-FG52-09NA29034, and DE-FC52-08NA28616.

Development of Powered Disk Type Sugar Cane Stubble Saver

Directory of Open Access Journals (Sweden)

Radite P.A.S.

2009-04-01

Full Text Available The objective of this research was to design, fabricate and test a prototype of sugar cane stubble saver based on powered disk mechanism. In this research, a heavy duty disk plow or disk harrow was used as a rotating knife to cut the sugarcane stubble. The parabolic disk was chosen because it is proven reliable as soil working tools and it is available in the market as spare part of disk plow or disk harrow unit. The prototype was mounted on the four wheel tractor’s three point hitch, and powered by PTO of the tractor. Two kinds of disks were used in these experiments, those were disk with regular edge or plain disk and disk with scalloped edge or scalloped disk. Both disks had diameter of 28 inch. Results of field test showed that powered disk mechanism could satisfy cut sugar cane’s stubble. However, scalloped disk type gave smoother stubble cuts compared to that of plain disk. Plain disk type gave broken stubble cut. Higher rotation (1000 rpm resulted better cuts as compared to lower rotation (500 rpm both either on plain disk and scalloped disk. The developed prototype could work below the soil surface at depth of 5 to 10 cm. With tilt angle setting 20O and disk angle 45O the width of cut was about 25 cm.

Classical and modern optimization methods in minimum weight design of elastic rotating disk with variable thickness and density

International Nuclear Information System (INIS)

Jafari, S.; Hojjati, M.H.; Fathi, A.

2012-01-01

Rotating disks work mostly at high angular velocity and this results a large centrifugal force and consequently induce large stresses and deformations. Minimizing weight of such disks yields to benefits such as low dead weights and lower costs. This paper aims at finding an optimal disk profiles for minimum weight design using the Karush-Kuhn-Tucker method (KKT) as a classical optimization method, simulated annealing (SA) and particle swarm optimization (PSO) as two modern optimization techniques. Some semi-analytical solutions for the elastic stress distribution in a rotating annular disk with uniform and variable thickness and density proposed by the authors in the previous works have been used. The von Mises failure criterion of optimum disk is used as an inequality constraint to make sure that the rotating disk does not fail. The results show that the minimum weight obtained for all three methods is almost identical. The KKT method gives a profile with slightly less weight (6% less than SA and 1% less than PSO) while the implementation of PSO and SA methods are easier and provide more flexibility compared with those of the KKT method. The effectiveness of the proposed optimization methods is shown. - Highlights: ► Karush-Kuhn-Tucker, simulated annealing and particle swarm methods are used. ► The KKT gives slightly less weight (6% less than SA and 1% less than PSO). ► Implementation of PSO and SA methods are easier and provide more flexibility. ► The effectiveness of the proposed optimization methods is shown.

Classical and modern optimization methods in minimum weight design of elastic rotating disk with variable thickness and density

Energy Technology Data Exchange (ETDEWEB)

Jafari, S. [Faculty of Mechanical Engineering, Babol University of Technology, P.O. Box 484, Babol (Iran, Islamic Republic of); Hojjati, M.H., E-mail: Hojjati@nit.ac.ir [Faculty of Mechanical Engineering, Babol University of Technology, P.O. Box 484, Babol (Iran, Islamic Republic of); Fathi, A. [Faculty of Mechanical Engineering, Babol University of Technology, P.O. Box 484, Babol (Iran, Islamic Republic of)

2012-04-15

Rotating disks work mostly at high angular velocity and this results a large centrifugal force and consequently induce large stresses and deformations. Minimizing weight of such disks yields to benefits such as low dead weights and lower costs. This paper aims at finding an optimal disk profiles for minimum weight design using the Karush-Kuhn-Tucker method (KKT) as a classical optimization method, simulated annealing (SA) and particle swarm optimization (PSO) as two modern optimization techniques. Some semi-analytical solutions for the elastic stress distribution in a rotating annular disk with uniform and variable thickness and density proposed by the authors in the previous works have been used. The von Mises failure criterion of optimum disk is used as an inequality constraint to make sure that the rotating disk does not fail. The results show that the minimum weight obtained for all three methods is almost identical. The KKT method gives a profile with slightly less weight (6% less than SA and 1% less than PSO) while the implementation of PSO and SA methods are easier and provide more flexibility compared with those of the KKT method. The effectiveness of the proposed optimization methods is shown. - Highlights: Black-Right-Pointing-Pointer Karush-Kuhn-Tucker, simulated annealing and particle swarm methods are used. Black-Right-Pointing-Pointer The KKT gives slightly less weight (6% less than SA and 1% less than PSO). Black-Right-Pointing-Pointer Implementation of PSO and SA methods are easier and provide more flexibility. Black-Right-Pointing-Pointer The effectiveness of the proposed optimization methods is shown.

A comparison of high-speed flywheels, batteries, and ultracapacitors on the bases of cost and fuel economy as the energy storage system in a fuel cell based hybrid electric vehicle

Energy Technology Data Exchange (ETDEWEB)

Doucette, Reed T.; McCulloch, Malcolm D. [Department of Engineering Science, University of Oxford, Thom Building, Parks Road, Oxford, OX1 3PJ (United Kingdom)

2011-02-01

Fuel cells aboard hybrid electric vehicles (HEVs) are often hybridized with an energy storage system (ESS). Batteries and ultracapacitors are the most common technologies used in ESSs aboard HEVs. High-speed flywheels are an emerging technology with traits that have the potential to make them competitive with more established battery and ultracapacitor technologies in certain vehicular applications. This study compares high-speed flywheels, ultracapacitors, and batteries functioning as the ESS in a fuel cell based HEV on the bases of cost and fuel economy. In this study, computer models were built to simulate the powertrain of a fuel cell based HEV where high-speed flywheels, batteries, and ultracapacitors of a range of sizes were used as the ESS. A simulated vehicle with a powertrain using each of these technologies was run over two different drive cycles in order to see how the different ESSs performed under different driving patterns. The results showed that when cost and fuel economy were both considered, high-speed flywheels were competitive with batteries and ultracapacitors. (author)

Circumstellar disks around binary stars in Taurus

Energy Technology Data Exchange (ETDEWEB)

Akeson, R. L. [NASA Exoplanet Science Institute, IPAC/Caltech, Pasadena, CA 91125 (United States); Jensen, E. L. N. [Swarthmore College, Department of Physics and Astronomy, Swarthmore, PA 19081 (United States)

2014-03-20

We have conducted a survey of 17 wide (>100 AU) young binary systems in Taurus with the Atacama Large Millimeter Array (ALMA) at two wavelengths. The observations were designed to measure the masses of circumstellar disks in these systems as an aid to understanding the role of multiplicity in star and planet formation. The ALMA observations had sufficient resolution to localize emission within the binary system. Disk emission was detected around all primaries and 10 secondaries, with disk masses as low as 10{sup –4} M {sub ☉}. We compare the properties of our sample to the population of known disks in Taurus and find that the disks from this binary sample match the scaling between stellar mass and millimeter flux of F{sub mm}∝M{sub ∗}{sup 1.5--2.0} to within the scatter found in previous studies. We also compare the properties of the primaries to those of the secondaries and find that the secondary/primary stellar and disk mass ratios are not correlated; in three systems, the circumsecondary disk is more massive than the circumprimary disk, counter to some theoretical predictions.

Design for a second-generation proton storage ring at LAMPF

International Nuclear Information System (INIS)

Colton, E.P.

1988-01-01

A conceptual design is presented for a second-generation proton storage ring complex at LAMPF. The facility would consist of two stacked racetrack-shaped machines. These machines would deliver a 1.2-mA beam of 1.6-GeV protons at 48 Hz. The pulse length would be 1.75 μsec which represents a time compression of 570. 1 ref., 8 figs., 1 tab

Radiative Transfer Modeling in Proto-planetary Disks

Science.gov (United States)

Kasper, David; Jang-Condell, Hannah; Kloster, Dylan

2016-01-01

Young Stellar Objects (YSOs) are rich astronomical research environments. Planets form in circumstellar disks of gas and dust around YSOs. With ever increasing capabilities of the observational instruments designed to look at these proto-planetary disks, most notably GPI, SPHERE, and ALMA, more accurate interfaces must be made to connect modeling of the disks with observation. PaRTY (Parallel Radiative Transfer in YSOs) is a code developed previously to model the observable density and temperature structure of such a disk by self-consistently calculating the structure of the disk based on radiative transfer physics. We present upgrades we are implementing to the PaRTY code to improve its accuracy and flexibility. These upgrades include: creating a two-sided disk model, implementing a spherical coordinate system, and implementing wavelength-dependent opacities. These upgrades will address problems in the PaRTY code of infinite optical thickness, calculation under/over-resolution, and wavelength-independent photon penetration depths, respectively. The upgraded code will be used to better model disk perturbations resulting from planet formation.

Disk-bend ductility tests for irradiated materials

International Nuclear Information System (INIS)

Klueh, R.L.; Braski, D.N.

1984-01-01

We modified the HEDL disk-bend test machine and are using it to qualitatively screen alloys that are susceptible to embrittlement caused by irradiation. Tests designed to understand the disk-bend test in relation to a uniaxial test are discussed. Selected results of tests of neutron-irradiated material are also presented

Effects of Traditional Versus Horizontal Inertial Flywheel Power Training on Common Sport-Related Tasks

Directory of Open Access Journals (Sweden)

de Hoyo Moisés

2015-09-01

Full Text Available This study aimed to analyze the effects of power training using traditional vertical resistance exercises versus direction specific horizontal inertial flywheel training on performance in common sport-related tasks. Twenty-three healthy and physically active males (age: 22.29 ± 2.45 years volunteered to participate in this study. Participants were allocated into either the traditional training (TT group where the half squat exercise on a smith machine was applied or the horizontal flywheel training (HFT group performing the front step exercise with an inertial flywheel. Training volume and intensity were matched between groups by repetitions (5-8 sets with 8 repetitions and relative intensity (the load that maximized power (Pmax over the period of six weeks. Speed (10 m and 20 m, countermovement jump height (CMJH, 20 m change of direction ability (COD and strength during a maximal voluntary isometric contraction (MVIC were assessed before and after the training program. The differences between groups and by time were assessed using a two-way analysis of variance with repeated measures, followed by paired t-tests. A significant group by time interaction (p=0.004 was found in the TT group demonstrating a significantly higher CMJH. Within-group analysis revealed statistically significant improvements in a 10 m sprint (TT: −0.17 0.27 s vs. HFT: −0.11 0.10 s, CMJH (TT: 4.92 2.58 cm vs. HFT: 1.55 2.44 cm and MVIC (TT: 62.87 79.71 N vs. HFT: 106.56 121.63 N in both groups (p < 0.05. However, significant differences only occurred in the 20 m sprint time in the TT group (−0.04 0.12 s; p = 0.04. In conclusion, the results suggest that TT at the maximal peak power load is more effective than HFT for counter movement jump height while both TT and HFT elicited significant improvements in 10 m sprint performance while only TT significantly improved 20 m sprint performance.

Vacuum system design for the PEP-II B Factory High-Energy Ring

International Nuclear Information System (INIS)

Perkins, C.; Bostic, D.; Daly, E.

1994-06-01

The design of the vacuum system for the PEP-II B Factory High-Energy Ring is reviewed. The thermal design and vacuum requirements are particularly challenging in PEP-II due to high stored beam currents up to 3.0 amps in 1658 bunches. The vacuum chambers for the HER arcs are fabricated by electron beam welding extruded copper sections up to 6 m long. Design of these chambers and the vacuum PumPing configuration is described with results from vacuum and thermal analyses

Design and construction of an Offner spectrometer based on geometrical analysis of ring fields.

Science.gov (United States)

Kim, Seo Hyun; Kong, Hong Jin; Lee, Jong Ung; Lee, Jun Ho; Lee, Jai Hoon

2014-08-01

A method to obtain an aberration-corrected Offner spectrometer without ray obstruction is proposed. A new, more efficient spectrometer optics design is suggested in order to increase its spectral resolution. The derivation of a new ring equation to eliminate ray obstruction is based on geometrical analysis of the ring fields for various numerical apertures. The analytical design applying this equation was demonstrated using the optical design software Code V in order to manufacture a spectrometer working in wavelengths of 900-1700 nm. The simulation results show that the new concept offers an analytical initial design taking the least time of calculation. The simulated spectrometer exhibited a modulation transfer function over 80% at Nyquist frequency, root-mean-square spot diameters under 8.6 μm, and a spectral resolution of 3.2 nm. The final design and its realization of a high resolution Offner spectrometer was demonstrated based on the simulation result. The equation and analytical design procedure shown here can be applied to most Offner systems regardless of the wavelength range.

Polarized Disk Emission from Herbig Ae/Be Stars Observed Using Gemini Planet Imager: HD 144432, HD 150193, HD 163296, and HD 169142

Energy Technology Data Exchange (ETDEWEB)

Monnier, John D.; Aarnio, Alicia; Adams, Fred C.; Calvet, Nuria; Hartmann, Lee [Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States); Harries, Tim J.; Hinkley, Sasha; Kraus, Stefan [University of Exeter, Exeter (United Kingdom); Andrews, Sean; Wilner, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 91023 (United States); Espaillat, Catherine [Boston University, Boston, MA (United States); McClure, Melissa [European Southern Observatory, Garching (Germany); Oppenheimer, Rebecca [American Museum of Natural History, New York (United States); Perrin, Marshall [Space Telescope Science Institute, Baltimore, MD (United States)

2017-03-20

In order to look for signs of ongoing planet formation in young disks, we carried out the first J -band polarized emission imaging of the Herbig Ae/Be stars HD 150193, HD 163296, and HD 169142 using the Gemini Planet Imager, along with new H band observations of HD 144432. We confirm the complex “double ring” structure for the nearly face-on system HD 169142 first seen in H -band, finding the outer ring to be substantially redder than the inner one in polarized intensity. Using radiative transfer modeling, we developed a physical model that explains the full spectral energy distribution and J - and H -band surface brightness profiles, suggesting that the differential color of the two rings could come from reddened starlight traversing the inner wall and may not require differences in grain properties. In addition, we clearly detect an elongated, off-center ring in HD 163296 (MWC 275), locating the scattering surface to be 18 au above the midplane at a radial distance of 77 au, co-spatial with a ring seen at 1.3 mm by ALMA linked to the CO snow line. Lastly, we report a weak tentative detection of scattered light for HD 150193 (MWC 863) and a non-detection for HD 144432; the stellar companion known for each of these targets has likely disrupted the material in the outer disk of the primary star. For HD 163296 and HD 169142, the prominent outer rings we detect could be evidence for giant planet formation in the outer disk or a manifestation of large-scale dust growth processes possibly related to snow-line chemistry.

Polarized Disk Emission from Herbig Ae/Be Stars Observed Using Gemini Planet Imager: HD 144432, HD 150193, HD 163296, and HD 169142

International Nuclear Information System (INIS)

Monnier, John D.; Aarnio, Alicia; Adams, Fred C.; Calvet, Nuria; Hartmann, Lee; Harries, Tim J.; Hinkley, Sasha; Kraus, Stefan; Andrews, Sean; Wilner, David; Espaillat, Catherine; McClure, Melissa; Oppenheimer, Rebecca; Perrin, Marshall

2017-01-01

In order to look for signs of ongoing planet formation in young disks, we carried out the first J -band polarized emission imaging of the Herbig Ae/Be stars HD 150193, HD 163296, and HD 169142 using the Gemini Planet Imager, along with new H band observations of HD 144432. We confirm the complex “double ring” structure for the nearly face-on system HD 169142 first seen in H -band, finding the outer ring to be substantially redder than the inner one in polarized intensity. Using radiative transfer modeling, we developed a physical model that explains the full spectral energy distribution and J - and H -band surface brightness profiles, suggesting that the differential color of the two rings could come from reddened starlight traversing the inner wall and may not require differences in grain properties. In addition, we clearly detect an elongated, off-center ring in HD 163296 (MWC 275), locating the scattering surface to be 18 au above the midplane at a radial distance of 77 au, co-spatial with a ring seen at 1.3 mm by ALMA linked to the CO snow line. Lastly, we report a weak tentative detection of scattered light for HD 150193 (MWC 863) and a non-detection for HD 144432; the stellar companion known for each of these targets has likely disrupted the material in the outer disk of the primary star. For HD 163296 and HD 169142, the prominent outer rings we detect could be evidence for giant planet formation in the outer disk or a manifestation of large-scale dust growth processes possibly related to snow-line chemistry.

The DiskMass Survey. II. Error Budget

Science.gov (United States)

Bershady, Matthew A.; Verheijen, Marc A. W.; Westfall, Kyle B.; Andersen, David R.; Swaters, Rob A.; Martinsson, Thomas

2010-06-01

We present a performance analysis of the DiskMass Survey. The survey uses collisionless tracers in the form of disk stars to measure the surface density of spiral disks, to provide an absolute calibration of the stellar mass-to-light ratio (Υ_{*}), and to yield robust estimates of the dark-matter halo density profile in the inner regions of galaxies. We find that a disk inclination range of 25°-35° is optimal for our measurements, consistent with our survey design to select nearly face-on galaxies. Uncertainties in disk scale heights are significant, but can be estimated from radial scale lengths to 25% now, and more precisely in the future. We detail the spectroscopic analysis used to derive line-of-sight velocity dispersions, precise at low surface-brightness, and accurate in the presence of composite stellar populations. Our methods take full advantage of large-grasp integral-field spectroscopy and an extensive library of observed stars. We show that the baryon-to-total mass fraction ({F}_bar) is not a well-defined observational quantity because it is coupled to the halo mass model. This remains true even when the disk mass is known and spatially extended rotation curves are available. In contrast, the fraction of the rotation speed supplied by the disk at 2.2 scale lengths (disk maximality) is a robust observational indicator of the baryonic disk contribution to the potential. We construct the error budget for the key quantities: dynamical disk mass surface density (Σdyn), disk stellar mass-to-light ratio (Υ^disk_{*}), and disk maximality ({F}_{*,max}^disk≡ V^disk_{*,max}/ V_c). Random and systematic errors in these quantities for individual galaxies will be ~25%, while survey precision for sample quartiles are reduced to 10%, largely devoid of systematic errors outside of distance uncertainties.

Dust-trapping Vortices and a Potentially Planet-triggered Spiral Wake in the Pre-transitional Disk of V1247 Orionis

Science.gov (United States)

Kraus, Stefan; Kreplin, Alexander; Fukugawa, Misato; Muto, Takayuki; Sitko, Michael L.; Young, Alison K.; Bate, Matthew R.; Grady, Carol; Harries, Tim T.; Monnier, John D.; Willson, Matthew; Wisniewski, John

2017-10-01

The radial drift problem constitutes one of the most fundamental problems in planet formation theory, as it predicts particles to drift into the star before they are able to grow to planetesimal size. Dust-trapping vortices have been proposed as a possible solution to this problem, as they might be able to trap particles over millions of years, allowing them to grow beyond the radial drift barrier. Here, we present ALMA 0.″04 resolution imaging of the pre-transitional disk of V1247 Orionis that reveals an asymmetric ring as well as a sharply confined crescent structure, resembling morphologies seen in theoretical models of vortex formation. The asymmetric ring (at 0.″17 = 54 au separation from the star) and the crescent (at 0.″38 = 120 au) seem smoothly connected through a one-armed spiral-arm structure that has been found previously in scattered light. We propose a physical scenario with a planet orbiting at ˜0.″3 ≈ 100 au, where the one-armed spiral arm detected in polarized light traces the accretion stream feeding the protoplanet. The dynamical influence of the planet clears the gap between the ring and the crescent and triggers two vortices that trap millimeter-sized particles, namely, the crescent and the bright asymmetry seen in the ring. We conducted dedicated hydrodynamics simulations of a disk with an embedded planet, which results in similar spiral-arm morphologies as seen in our scattered-light images. At the position of the spiral wake and the crescent we also observe 12CO(3-2) and H12CO+ (4-3) excess line emission, likely tracing the increased scale-height in these disk regions.

Stirling engine piston ring

Science.gov (United States)

Howarth, Roy B.

1983-01-01

A piston ring design for a Stirling engine wherein the contact pressure between the piston and the cylinder is maintained at a uniform level, independent of engine conditions through a balancing of the pressure exerted upon the ring's surface and thereby allowing the contact pressure on the ring to be predetermined through the use of a preloaded expander ring.

VUV optical ring resonator for Duke storage ring free electron laser

Energy Technology Data Exchange (ETDEWEB)

Park, S.H.; Litvinenko, V.N.; Madey, J.M.J. [Duke Univ., Durham, NC (United States)] [and others

1995-12-31

The conceptual design of the multifaceted-mirror ring resonator for Duke storage ring VUV FEL is presented. The expected performance of the OK-4 FEL with ring resonator is described. We discuss in this paper our plans to study reflectivity of VUV mirrors and their resistivity to soft X-ray spontaneous radiation from OK-4 undulator.

A ring system detected around the Centaur (10199) Chariklo.

Science.gov (United States)

Braga-Ribas, F; Sicardy, B; Ortiz, J L; Snodgrass, C; Roques, F; Vieira-Martins, R; Camargo, J I B; Assafin, M; Duffard, R; Jehin, E; Pollock, J; Leiva, R; Emilio, M; Machado, D I; Colazo, C; Lellouch, E; Skottfelt, J; Gillon, M; Ligier, N; Maquet, L; Benedetti-Rossi, G; Ramos Gomes, A; Kervella, P; Monteiro, H; Sfair, R; El Moutamid, M; Tancredi, G; Spagnotto, J; Maury, A; Morales, N; Gil-Hutton, R; Roland, S; Ceretta, A; Gu, S-h; Wang, X-b; Harpsøe, K; Rabus, M; Manfroid, J; Opitom, C; Vanzi, L; Mehret, L; Lorenzini, L; Schneiter, E M; Melia, R; Lecacheux, J; Colas, F; Vachier, F; Widemann, T; Almenares, L; Sandness, R G; Char, F; Perez, V; Lemos, P; Martinez, N; Jørgensen, U G; Dominik, M; Roig, F; Reichart, D E; LaCluyze, A P; Haislip, J B; Ivarsen, K M; Moore, J P; Frank, N R; Lambas, D G

2014-04-03

Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 ±  9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.

Hubble again views Saturn's Rings Edge-on

Science.gov (United States)

1995-01-01

Saturn's magnificent ring system is seen tilted edge-on -- for the second time this year -- in this NASA Hubble Space Telescope picture taken on August 10, 1995, when the planet was 895 million miles (1,440 million kilometers) away. Hubble snapped the image as Earth sped back across Saturn's ring plane to the sunlit side of the rings. Last May 22, Earth dipped below the ring plane, giving observers a brief look at the backlit side of the rings. Ring-plane crossing events occur approximately every 15 years. Earthbound observers won't have as good a view until the year 2038. Several of Saturn's icy moons are visible as tiny starlike objects in or near the ring plane. They are from left to right, Enceladus, Tethys, Dione and Mimas. 'The Hubble data shows numerous faint satellites close to the bright rings, but it will take a couple of months to precisely identify them,' according to Steve Larson (University of Arizona). During the May ring plane crossing, Hubble detected two, and possibly four, new moons orbiting Saturn. These new observations also provide a better view of the faint E ring, 'to help determine the size of particles and whether they will pose a collision hazard to the Cassini spacecraft,' said Larson. The picture was taken with Hubble's Wide Field Planetary Camera 2 in wide field mode. This image is a composite view, where a long exposure of the faint rings has been combined with a shorter exposure of Saturn's disk to bring out more detail. When viewed edge-on, the rings are so dim they almost disappear because they are very thin -- probably less than a mile thick.The Wide Field/Planetary Camera 2 was developed by the Jet Propulsion Laboratory and managed by the Goddard Spaced Flight Center for NASA's Office of Space Science.This image and other images and data received from the Hubble Space Telescope are posted on the World Wide Web on the Space Telescope Science Institute home page at URL http://oposite.stsci.edu/pubinfo/

Magnetic ring for stripping enhancement

International Nuclear Information System (INIS)

Selph, F.

1992-10-01

A ring designed to recycle ions through a stripping medium offers the possibility for increasing output of the desired charge state by up to 4x. This could be a very important component of a Radioactive Nuclear Beam Facility. In order for such a ring to work effectively it must satisfy certain design conditions. These include achromaticity at the stripper, a dispersed region for an extraction magnet, and a number of first and higher order optics constraints which are necessary to insure that the beam emittance is not degraded unduly by the ring. An example is given of a candidate design of a stripping ring

Identifying Likely Disk-hosting M dwarfs with Disk Detective