The Experts below are selected from a list of 149256 Experts worldwide ranked by ideXlab platform

Roger Mcwilliams - One of the best experts on this subject based on the ideXlab platform.

  • Ion acceleration and anomalous Transport in the near wake of a plasma limiter
    Physics of Plasmas, 1997
    Co-Authors: Daniel P. Sheehan, J. Bowles, Roger Mcwilliams
    Abstract:

    Ion acceleration and anomalous Transport were studied experimentally in the near wake region of an electrically floating disk limiter immersed in two different types of collisionless, supersonically flowing, magnetized plasmas: the first initially quiescent, the second initially turbulent. Ion densities and velocity distributions were obtained using a nonperturbing laser induced fluorescence diagnostic. Large-amplitude, low-frequency turbulence was observed at the obstacle edge and in the wake. Rapid ion and electron configuration Space Transport and ion velocity Space Transport were observed. Configuration Space and velocity Space Transport were similar for both quiescent and turbulent plasma-obstacle systems, suggesting that plasma-obstacle effects outweigh the effects of initial plasma turbulence levels.

  • Direct measurement of velocity Space Transport in a plasma
    Physics of Plasmas, 1994
    Co-Authors: Jeffrey H. Bowles, Roger Mcwilliams, N. Rynn
    Abstract:

    The direct measurement of the velocity Space Transport of ions in a plasma is reported. Measured diffusion and convection coefficients are compared to the calculated Fokker–Planck coefficients for a fully ionized plasma. The measurements were made in a Q‐machine barium plasma (Ti=Te= 0.17 eV, 5×108≤n≤8×109 cm−3) with both high and low fluctuation levels. At low fluctuation levels the measured coefficients agree with classical collision theory. Coefficients measured in the presence of large amplitude fluctuations generally are larger and have different velocity dependences. Test particle distributions are created and interrogated using the technique of optical tagging. The short‐time (≪90° collision time) relaxation of the test particle distribution function was measured as a function of density and temperature of the background plasma and as a function of the velocity of the test particle distribution. The values of the convection and diffusion coefficients were extracted from these measurements. Longer t...

  • Direct measurement of velocity-Space Transport in a fully ionized plasma
    Physical review letters, 1992
    Co-Authors: Jeffrey H. Bowles, Roger Mcwilliams, N. Rynn
    Abstract:

    Direct measurements of velocity-Space Transport coefficients, which may be interpreted as the Fokker-Planck coefficients, in the direction of the confining magnetic field are reported. The measurements were made using the techniques of laser-induced fluorescence and optical tagging, which allow ions to be followed in phase Space. The results show that in a plasma with nearly only thermal fluctuations the data agree well with test particle calculations made by N. Rostoker for classical collisional processes. In the presence of larger-amplitude drift-wave fluctuations there is a pronounced enhancement of the velocity diffusion coefficient at a velocity less than the thermal speed.

Jerry L. Decker - One of the best experts on this subject based on the ideXlab platform.

  • Frame Dragging Remedy for Polarizable Vacuum Theory at High Speed in Deep Space Transport
    viXra, 2016
    Co-Authors: Jerry L. Decker
    Abstract:

    Frame dragging resulted from modifications of Polarizable Vacuum Theory that were done to bring high velocity terms into PV consistent with established science of energy and momentum at high speed. It was found that velocity terms could not be brought into PV theory without formalism for exchange of kinetic energy with the vacuum Space. Planck’s Law in general and Heisenberg Uncertainty in a specific case were used to develop a mechanism for continual exchange of kinetic energy with the local vacuum. The mechanism calls for incurring equal exchange of energy with Space when acceleration does not occur, and unequal exchange when a physical object is accelerating. Accumulating kinetic energy in Space was found to polarize the vacuum in a way equivalent to the polarizing parameter K of Harold Puthoff.(1) Frame dragging results from the continual increase of vacuum stress energy trailing longitudinally and propagating transversely from an accelerating deep Space vehicle. Introduction A previous attempt to extend Polarizable Vacuum theory of Harold Puthoff(2) and others to high speed in deep Space led to modifications of PV for adding velocity terms in agreement with established laws of energy and momentum. The mass function was redeveloped for consistency with widely published

  • Failure Of Lorentz Transforms For Deep Space Transport at High Speed
    viXra, 2016
    Co-Authors: Jerry L. Decker
    Abstract:

    Lorentz Transformations of flat Space were found to be inappropriate at high speed in deep Space Transport. Curvature of vacuum stress energy was predicted to accumulate from prolonged acceleration boosting of a Space vehicle. Support was found for previous work on modifications of Polarizable Vacuum theory.

  • High Speed In Deep Space Transport With Partition Of The Polarized Vacuum
    viXra, 2015
    Co-Authors: Jerry L. Decker
    Abstract:

    Predictions are made for properties of Space and time at increasing speed related to Deep Space Transport using a combination of Vacuum Partition with Polarizable Vacuum Theory as modified for high velocity.

  • Deep Space Transport With Field Effect Of Vacuum Stress Energy
    viXra, 2015
    Co-Authors: Jerry L. Decker
    Abstract:

    Stress energy of general relativity is developed from interference patterns of electromagnetic waves where all of the electric and magnetic components are canceled out, but the Poynting vectors are not canceled. Curved Space in the vicinity of the Transport vehicle is shown to be equivalent to an induced gravitational field off set from the center of mass in the vehicle. A proposal is made that high acceleration can be achieved by field effect gravitational free fall in deep Space Transport removing traditional limits on acceleration for the vehicle and crew.

  • Magnetic Engines For Low Orbit Leading to Development of Deep Space Transport
    viXra, 2015
    Co-Authors: Jerry L. Decker
    Abstract:

    Magnetic engines are proposed for saving energy in surface to orbit launches by interacting with the magnetic field of Earth. Difficulties are discussed with proposals for ways to overcome obstacles and mitigate risk. Stability and directional control are the main design parameters. The components of the magnetic lifters are suitable for configuring a test of field effect propulsion, leading to the possibility of deep Space Transport.

N. Rynn - One of the best experts on this subject based on the ideXlab platform.

  • Direct measurement of velocity Space Transport in a plasma
    Physics of Plasmas, 1994
    Co-Authors: Jeffrey H. Bowles, Roger Mcwilliams, N. Rynn
    Abstract:

    The direct measurement of the velocity Space Transport of ions in a plasma is reported. Measured diffusion and convection coefficients are compared to the calculated Fokker–Planck coefficients for a fully ionized plasma. The measurements were made in a Q‐machine barium plasma (Ti=Te= 0.17 eV, 5×108≤n≤8×109 cm−3) with both high and low fluctuation levels. At low fluctuation levels the measured coefficients agree with classical collision theory. Coefficients measured in the presence of large amplitude fluctuations generally are larger and have different velocity dependences. Test particle distributions are created and interrogated using the technique of optical tagging. The short‐time (≪90° collision time) relaxation of the test particle distribution function was measured as a function of density and temperature of the background plasma and as a function of the velocity of the test particle distribution. The values of the convection and diffusion coefficients were extracted from these measurements. Longer t...

  • Direct measurement of velocity-Space Transport in a fully ionized plasma
    Physical review letters, 1992
    Co-Authors: Jeffrey H. Bowles, Roger Mcwilliams, N. Rynn
    Abstract:

    Direct measurements of velocity-Space Transport coefficients, which may be interpreted as the Fokker-Planck coefficients, in the direction of the confining magnetic field are reported. The measurements were made using the techniques of laser-induced fluorescence and optical tagging, which allow ions to be followed in phase Space. The results show that in a plasma with nearly only thermal fluctuations the data agree well with test particle calculations made by N. Rostoker for classical collisional processes. In the presence of larger-amplitude drift-wave fluctuations there is a pronounced enhancement of the velocity diffusion coefficient at a velocity less than the thermal speed.

Adam J. Pel - One of the best experts on this subject based on the ideXlab platform.

  • The influence of integrated Space–Transport development strategies on air pollution in urban areas
    Transportation Research Part D: Transport and Environment, 2016
    Co-Authors: Lasmini Ambarwati, Robert Verhaeghe, Bart Van Arem, Adam J. Pel
    Abstract:

    The phenomenon of urban sprawl has strong impacts on Transport performance and accessibility and causes an increase of air pollution. Effective control of urban sprawl requires an integrated approach comprising urban Transport and land-use planning. Current research is insufficient to demonstrate the effects of urban sprawl on travel behavior and air pollution emission. The present paper examines the potential of an integrated approach on Space–Transport development strategies with the aim of increasing accessibility and reducing air pollution. A combination of Space and Transport strategies has been simulated for the rapidly expanding city of Surabaya. A comparative analysis of the impact of those cases indicates the promising potential alternatives to minimize the phenomenon. The Transport options considered are combinations of Public Transport (PT), comprising Mass Rapid Transit (MRT), Light Rapid Transit (LRT), and Bus Rapid Transit (BRT). The options for urban structure include a compact zone development for the city, as formulated by the city planning agency, and a polycentric city set-up based on a job-housing balance aimed at minimizing the house-job distance. The results indicate that the polycentric city structure has the potential to make public Transport work successfully for the city of Surabaya. This city structure creates a trip demand pattern which matches citizens’ PT preferences. Compared to the current situation, the combination of such a city structure with an expansion of PT systems would lead to a considerable improvement of Transport performance, i.e. a PT mode share, a mean commute distance, and a significant reduction in emissions.

  • Controlling Urban Sprawl with Integrated Approach of Space- Transport Development Strategies
    Procedia - Social and Behavioral Sciences, 2014
    Co-Authors: Lasmini Ambarwati, Robert Verhaeghe, Adam J. Pel, Bart Van Arem
    Abstract:

    Urban sprawl phenomenon has been a huge issue since 20th century characterized by a rapid and unbalanced settlement development with Transportation network particularly in a suburban area. The improvement of public Transport system is a major requirement to minimize urban sprawl. Academic researchers have explained the linkage strategy between Transportation network and urban planning. However, insufficient empirical verification has been made to control this phenomenon by using the integrated approach of Space-Transport development. This paper focuses on analyzing the improvement of public Transport supply incorporated with settlement development. The improvement of public Transport (PT) is designed by planning Mass Rapid Transit (MRT), Light Rapid Transit (LRT), and Bus Rapid Transit (BRT) systems. The impact of PT improvement has affected on the settlement development. Setting balance between employment and population density is designed as alternative of urban spatial strategy. These approaches are necessary in order to analyze and evaluate the many alternatives to overcome this situation. The result reveals that the requirement to integrate the Space-Transport development strategy in order to control the settlement development in the suburb has to be done to reduce 10% of travel time and to increase double the usage possibility to public Transport mode. The strategies should be done in the further research with considering on impact assessment and the residents preferences intended to determine the preferred and strategic option for them.

Lasmini Ambarwati - One of the best experts on this subject based on the ideXlab platform.

  • Can the design of Space-Transport development strategies influence on noise pollution?
    MATEC Web of Conferences, 2017
    Co-Authors: Lasmini Ambarwati, Amelia Kusuma Indriastuti, Yatnanta Padma Devia, Deputri N. Sari
    Abstract:

    The rapid growth of Transportation in developing countries brings advantages and disadvantages. One of the disadvantages gives negative impacts, such as traffic jam, which directly decreases a highway performance as well as increases air and noise pollution. A suitable policy has not been formulated to overcome the traffic jam in most highways in big cities. However, traffic demand management regard to noise pollution is required in most cities of developing countries, particularly Surabaya City, as a case study area. This study aims to understand the influence of saturated flow of highway on noise pollution for several types of road corridors. The results reveal that saturated flow of highway has a significant effect on noise pollution. By examining the alternatives of Space-Transport development strategies, the intention is to reduce noise pollution together with decreasing traffic jam due to decreasing the number of light vehicles. This research proposes the improvement of public Transport (PT) by planning a Mass Rapid Transit ((MRT). In addition, a structure of compact zones is designed as urban spatial strategy alternatives. Its substantially reduction is achieved with the design of improvement of PT systems and compact zone. The best option for reducing noise pollution level, the implementation of an integrated Space-Transport development strategy, is then recommended.

  • The influence of integrated Space–Transport development strategies on air pollution in urban areas
    Transportation Research Part D: Transport and Environment, 2016
    Co-Authors: Lasmini Ambarwati, Robert Verhaeghe, Bart Van Arem, Adam J. Pel
    Abstract:

    The phenomenon of urban sprawl has strong impacts on Transport performance and accessibility and causes an increase of air pollution. Effective control of urban sprawl requires an integrated approach comprising urban Transport and land-use planning. Current research is insufficient to demonstrate the effects of urban sprawl on travel behavior and air pollution emission. The present paper examines the potential of an integrated approach on Space–Transport development strategies with the aim of increasing accessibility and reducing air pollution. A combination of Space and Transport strategies has been simulated for the rapidly expanding city of Surabaya. A comparative analysis of the impact of those cases indicates the promising potential alternatives to minimize the phenomenon. The Transport options considered are combinations of Public Transport (PT), comprising Mass Rapid Transit (MRT), Light Rapid Transit (LRT), and Bus Rapid Transit (BRT). The options for urban structure include a compact zone development for the city, as formulated by the city planning agency, and a polycentric city set-up based on a job-housing balance aimed at minimizing the house-job distance. The results indicate that the polycentric city structure has the potential to make public Transport work successfully for the city of Surabaya. This city structure creates a trip demand pattern which matches citizens’ PT preferences. Compared to the current situation, the combination of such a city structure with an expansion of PT systems would lead to a considerable improvement of Transport performance, i.e. a PT mode share, a mean commute distance, and a significant reduction in emissions.

  • Controlling Urban Sprawl with Integrated Approach of Space- Transport Development Strategies
    Procedia - Social and Behavioral Sciences, 2014
    Co-Authors: Lasmini Ambarwati, Robert Verhaeghe, Adam J. Pel, Bart Van Arem
    Abstract:

    Urban sprawl phenomenon has been a huge issue since 20th century characterized by a rapid and unbalanced settlement development with Transportation network particularly in a suburban area. The improvement of public Transport system is a major requirement to minimize urban sprawl. Academic researchers have explained the linkage strategy between Transportation network and urban planning. However, insufficient empirical verification has been made to control this phenomenon by using the integrated approach of Space-Transport development. This paper focuses on analyzing the improvement of public Transport supply incorporated with settlement development. The improvement of public Transport (PT) is designed by planning Mass Rapid Transit (MRT), Light Rapid Transit (LRT), and Bus Rapid Transit (BRT) systems. The impact of PT improvement has affected on the settlement development. Setting balance between employment and population density is designed as alternative of urban spatial strategy. These approaches are necessary in order to analyze and evaluate the many alternatives to overcome this situation. The result reveals that the requirement to integrate the Space-Transport development strategy in order to control the settlement development in the suburb has to be done to reduce 10% of travel time and to increase double the usage possibility to public Transport mode. The strategies should be done in the further research with considering on impact assessment and the residents preferences intended to determine the preferred and strategic option for them.