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Sample records for air cushion vehicle

  1. Nuclear air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    The state-of-the-art of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant is identified. Using mission studies and cost estimates, some of the advantages of nuclear power for large air cushion vehicles are described. The technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies are summarized.

  2. Nuclear air cushion vehicles.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  3. Air cushion vehicles: A briefing

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Finnegan, P. M.

    1971-01-01

    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

  4. Air cushion vehicles - Any potential for Canada?

    NASA Astrophysics Data System (ADS)

    Laframboise, J. F.

    1987-09-01

    The present evaluation of air cushion vehicle (ACV) operational and commercial suitability in the Canadian context notes that the most successful and durable ACV applications are those in which only ACVs can perform the required mission. An important factor is the reliability of the craft being tested in a given field of operations. Because of their low ground pressure, ACVs can operate over low-cost trails with an efficiency that compares with that of trucks over conventional roads; this renders them especially attractive for transportation networks in the North West Territories.

  5. Air cushion vehicles for arctic operation

    NASA Astrophysics Data System (ADS)

    Koleser, J.; Lavis, D. R.

    1986-09-01

    Attention is given to the results of the NAVSEA FY85 Surface Ship Concept Formulation Design Study for an initial operational capability year-2000 air cushion vehicle (ACV) suitable for logistics and general search/rescue duties in the Arctic. Two designs were developed during the study; the first utilized an ACV design synthesis math model while the second evolved as a derivative of an existing U.S. production craft. Both are regarded as feasible from an engineering and naval architectural standpoint. Results of performance and cost trade-off studies suggest that, for an Arctic ACV, gas turbines are the preferred power plant choice and an aluminum alloy is the preferred hull structural material choice. The most appropriate skirt height is approximately 12 ft.

  6. Simulation study of plane motion of air cushion vehicle

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACVs voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACVs movement characteristic basically.

  7. Developments in skirt systems for air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  8. Open tube guideway for high speed air cushioned vehicles

    NASA Technical Reports Server (NTRS)

    Goering, R. S. (inventor)

    1974-01-01

    This invention is a tubular shaped guideway for high-speed air-cushioned supported vehicles. The tubular guideway is split and separated such that the sides of the guideway are open. The upper portion of the tubular guideway is supported above the lower portion by truss-like structural members. The lower portion of the tubular guideway may be supported by the terrain over which the vehicle travels, on pedestals or some similar structure.

  9. Northwest passage: Trade route for large air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  10. Creating new cities through the large air-cushion vehicle.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Finnegan, P. M.

    1972-01-01

    The air-cushion vehicle (ACV) can travel over concrete roads, grass, sand, mud, swamp, snow, ice, and water. This mobility makes possible a totally new geographical freedom in choosing transportation routes, locating ports, and laying out a city. By the 1980s fleets of large ACV freighters could begin carrying ocean-going cargo. The mobility of an ACV fleet would allow placing hoverports away from areas now crowded. New cities could rise along shallow or reef-bound seacoasts and rivers, just as cities once rose around deep-water seaports.

  11. Thirty years of research and development of air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Bertelsen, William R.

    This paper describes the conception of the air cushion vehicle (ACV) from experiments with the ground effect of a VTOL aircraft model. Then it describes the evolution of the ultimate ACV drive system through building and testing many models and 16 full-scale ACV to arrive at complete controllability. Adequate control of the frictionless craft, which are without inherent yaw stability, requires control force of the order of magnitude of propulsion. The derived gimbal fans provide such control force in the form of direct thrust, which is instantly available in any of 360 degrees, meterable, instantly cancelable, and reversible.

  12. Operational noise data for the LACV-30 air cushion vehicle

    NASA Astrophysics Data System (ADS)

    Schomer, P. D.

    1985-03-01

    Operational data for the LACV-30 air cushion vehicle were gathered and developed into sound exposure level vs distance curves. These data are available for the Army Environmental Hygiene Agency (AEHA) to use in developing noise zone maps for LACV-30 operations in support of the Army Installation Compatible Use Program (ICUZ). ICUZ defines Hand use compatible with various noise levels and establishes a policy for achieving such uses. Although the Army classifies the LACV-30 as an amphibious vehicle, an examination of its noise characteristics and operations showed it most closely resembles a helicopter. Thus, the methodology for gathering rotary wing aircraft data was used. Measurements of LACV-30's passby runs over water at various distances and speeds were similar in concept to flyover and flyby measurements for helicopters, and the land maneuver measurements corresponded most nearly to a helicopter's hover measurements.

  13. Computer-aided conceptual design of Air Cushion Vehicles

    NASA Astrophysics Data System (ADS)

    Band, E. G. U.; Lavis, D. R.

    This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

  14. Linear Heave Dynamics of an Air-Cushion Vehicle Bag-and-Finger Skirt

    NASA Astrophysics Data System (ADS)

    Chung, Joon; Sullivan, Phillip A.

    Results from a linear analysis of the heave dynamics of an air-cushion vehicle equipped with a bag-and-finger skirt are described. A two-dimensional section of the cushion is subject to pure heave or long-wave surface motion inputs. The skirt mass is lumped in the fingers, with the bag being modelled as a combination of massless inelastic membranes and links. The airflows from bag to cushion and from cushion to atmosphere are assumed quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. For a configuration representative of a 37t vehicle, frequency response characteristics show the effect of skirt geometry and mass changes, and cushion capacitance. The results suggest that changes in skirt geometry cannot be used to radically modify an undesirable heave response, but reducing the skirt mass may be effective. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent at the low cushion-flow rates now used in practice.

  15. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    ERIC Educational Resources Information Center

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an

  16. Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica

    NASA Astrophysics Data System (ADS)

    Dibbern, J. S.

    1987-02-01

    This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

  17. Theoretical investigation of heave dynamics of an air cushion vehicle bag and finger skirt

    NASA Astrophysics Data System (ADS)

    Chung, Joon

    This thesis describes a theoretical investigation of the nonlinear and linear heave dynamics of an air cushion vehicle (ACV) equipped with a bag and finger skirt system with the purpose of understanding the skirt's effect on the vehicle heave dynamics. Throughout the course of this work, the pure heave motion of a two dimensional section of the skirt is investigated using several mathematical models. Both the nonlinear and linearized analyses include a detailed model of the skirt geometry, which is modelled as a combination of inelastic membranes and links. Air flow processes from the bag to the cushion and from the cushion to the atmosphere are assumed to be quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. The modulation of the escaping cushion air by skirt-ground contact is also included. The nonlinear simulations reveal that characteristically nonlinear dynamical phenomena such as period doubling and chaos can be expected to occur during the normal operation of ACVs. Furthermore, a configuration representative of a 37 tonne vehicle shows a resonance at frequencies in the range for which humans are most sensitive. Although these results thus show that some aspects of the bag and finger skirt heave dynamics can be highly nonlinear, they indicate that under certain circumstances, standard linear techniques can yield useful insights. Results from the linear analysis suggest that changes in skirt geometry cannot be used to radically modify the undesirable heave response of the bag and finger skirt, but reducing the skirt mass is quite effective. The pneumatic capacitance of the bag and cushion volume proves to be an important factor in the heave response. In particular, it contributes to heave instability. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent as the flow rate is reduced. The importance of unsteady fan effects on ACV dynamics is investigated by the application of a measured frequency response scaled from a small laboratory fan. The results showed that the unsteady fan has a significant impact on the heave response, and that it introduces major phase-shifts in the neighbourhood of the skirt resonance. These effects contribute to instability.

  18. Design criteria for light high speed desert air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  19. Linear analysis of the heave dynamics of a bag and finger air cushion vehicle skirt

    NASA Astrophysics Data System (ADS)

    Ma, T.; Sullivan, P. A.

    1986-09-01

    A linear analysis of the heave dynamics of an air-cushion vehicle bag and finger skirt is presented. A simplified geometry is considered; this is a two-dimensional section of the skirt without interior compartmentation. The bag is modeled as a membrane having distributed mass and viscoelasticity, and the fingers are modeled as rigid bodies having both mass and moment of inertia. A finite-element technique is used to discretize the equations of motion of the bag, but otherwise standard linear analysis techniques are used to obtain predictions of frequency response and stability characteristics. The stability results confirm the experimental observation that the dominant factor controlling the onset of skirt bounce is the bag-to-cushion pressure ratio.

  20. Progress report on Bertelsen research and development of an air cushion crawler all-terrain vehicle

    NASA Astrophysics Data System (ADS)

    Bertelsen, W. R.

    1987-06-01

    The ACV is an exceptional amphibian but it is not, nor is any other existing craft, an all-terrain vehicle (ATV). Using the best elements of the ACV in an air-cushion crawler tractor, a true ATV can be attained. A conventional crawler drive train will propel two tracks as pressurized, propulsive pontoons. The key to a successful ATV is in perfecting efficient, durable, sliding seals to allow the belt to move in its orbit around the track unit and maintain its internal pressure. After deriving the adequate seal, a 12 inch wide x 86 inch long endless rubber belt was fitted bilateral seals and slide plates with internal guide wheels fore and aft with a 21 inch wheel base. From this approximately one-quarter scale model, full-scale air track crawlers, true ATVs, of any size and capacity can be produced.

  1. Impact studies of a 1/3-scale model of an air cushion vehicle

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1985-01-01

    An experimental investigation was conducted to determine the effects of various parameters of the impact performance of a 1/3-scale dynamic model of an air cushion vehicle. Impact response was determined by measuring the maximum values of variables, including sidelobe, front lobe, and cavity pressures, normal acceleration, pitch and roll angles, and vertical displacement during impact, for various combinations of drop height, initial pitch and roll angles, and forward speed. Increasing initial pitch angle increased the maximum values of the front lobe pressure, normal acceleration, nose down pitch angle, and to some extent, vertical displacement, but it inversely affected the maximum cavity pressure. Increasing the drop height of the model increased the potential energy of the system and generally produced larger responses over the entire range of variables measured, except for the roll angle after impact, which remained constant. Forward speed had no effect on the impact performance of the model, except for essentially doubling the maximum nose down pitch angle after impact at the maximum speed tested.

  2. Air cushion landing gear applications study

    NASA Technical Reports Server (NTRS)

    Earl, T. D.

    1979-01-01

    A series of air cushion landing gear (ACLG) applications was studied and potential benefits analyzed in order to identify the most attractive of these. The selected applications are new integrated designs (not retrofits) and employ a modified design approach with improved characteristics and performance. To aid the study, a survey of potential users was made. Applications were evaluated in the light of comments received. A technology scenario is developed, with discussion of problem areas, current technology level and future needs. Feasible development timetables are suggested. It is concluded that near-term development of small-size ACLG trunks, exploration of flight effects and braking are key items. The most attractive applications are amphibious with very large cargo aircraft and small general aviation having the greatest potential.

  3. 1986 CACTS International Conference on Air Cushion Technology, Toronto, Canada, Sept. 16-18, 1986, Preprints

    NASA Astrophysics Data System (ADS)

    MacEwen, W. R.

    The present conference on the design and development, innovative configurational concepts, test result analyses and operational characteristics of ACVs gives attention to design criteria for light, high-speed ACVs in desert environments, preliminary over-water tests of linear propellers, tests on high speed hovercraft icebreaking, and the performance of an air cushion crawler all-terrain vehicle. Also discussed are the use of ACVs as high speed ASW vehicles, performance criteria for air cushion heave dynamics, the bounce characteristics of an ACV's responsive skirt, and the use of hovercraft in ice enforcement.

  4. Braking and cornering studies on an air cushion landing system

    NASA Technical Reports Server (NTRS)

    Daugherty, R. H.

    1983-01-01

    An experimental investigation was conducted to evaluate several concepts for braking and steering a vehicle equipped with an air cushion landing system (ACLS). The investigation made use of a modified airboat equipped with an ACLS. Braking concepts were characterized by the average deceleration of the vehicle. Reduced lobe flow and cavity venting braking concepts were evaluated in this program. The cavity venting braking concept demonstrated the best performance, producing decelerations on the test vehicle on the same order as moderate braking with conventional wheel brakes. Steering concepts were evaluated by recording the path taken while attempting to follow a prescribed maneuver. The steering concepts evaluated included using rudders only, using differential lobe flow, and using rudders combined with a lightly loaded, nonsteering center wheel. The latter concept proved to be the most accurate means of steering the vehicle on the ACLS, producing translational deviations two to three times higher than those from conventional nose-gear steering. However, this concept was still felt to provide reasonably precise steering control for the ACLS-equipped vehicle.

  5. Air-cushion tankers for Alaskan North Slope oil

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    A concept is described for transporting oil from the Arctic to southern markets in 10,000-ton, chemically fueled air-cushion vehicles (ACV's) configured as tankers. Based on preliminary cost estimates the conceptual ACV tanker system as tailored to the transportation of Alaskan North Slope oil could deliver the oil for about the same price per barrel as the proposed trans-Alaska pipeline with only one-third of the capital investment. The report includes the description of the conceptual system and its operation; preliminary cost estimates; an appraisal of ACV tanker development; and a comparison of system costs, versatility, vulnerability, and ecological effect with those of the trans-Alaska pipeline.

  6. Experimental and analytical studies of advanced air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Lee, E. G. S.; Boghani, A. B.; Captain, K. M.; Rutishauser, H. J.; Farley, H. L.; Fish, R. B.; Jeffcoat, R. L.

    1981-01-01

    Several concepts are developed for air cushion landing systems (ACLS) which have the potential for improving performance characteristics (roll stiffness, heave damping, and trunk flutter), and reducing fabrication cost and complexity. After an initial screening, the following five concepts were evaluated in detail: damped trunk, filled trunk, compartmented trunk, segmented trunk, and roll feedback control. The evaluation was based on tests performed on scale models. An ACLS dynamic simulation developed earlier is updated so that it can be used to predict the performance of full-scale ACLS incorporating these refinements. The simulation was validated through scale-model tests. A full-scale ACLS based on the segmented trunk concept was fabricated and installed on the NASA ACLS test vehicle, where it is used to support advanced system development. A geometrically-scaled model (one third full scale) of the NASA test vehicle was fabricated and tested. This model, evaluated by means of a series of static and dynamic tests, is used to investigate scaling relationships between reduced and full-scale models. The analytical model developed earlier is applied to simulate both the one third scale and the full scale response.

  7. A theoretical study of limit cycle oscillations of plenum air cushions

    NASA Astrophysics Data System (ADS)

    Hinchey, M. J.; Sullivan, P. A.

    1981-11-01

    Air cushion vehicles (ACV) are prone to the occurrence of dynamic instabilities which frequently appear as stable finite amplitude oscillations. The aim of this work is to ascertain if the non-linearities characteristics of ACV dynamics generate limit cycle oscillations for cushion systems operating at conditions for which a linear theory predicts instability. The types of non-linearity that can occur are discussed, and an analysis is presented for a single cell flexible skirted plenum chamber constrained to move in pure heave only. Two cushion feed cases are considered: a plenum box supply and a duct. The results obtained by a Galerkin/describing function analysis are compared with those generated by a full numerical simulation. For the plenum box supply system, it is shown that the limit cycles can be suppressed by using a piston to introduce high frequency small amplitude volume oscillations into the plenum chamber.

  8. A review and assessment of methods for prediction of the dynamic stability of air cushions

    NASA Astrophysics Data System (ADS)

    Sullivan, P. A.; Hinchey, M. J.; Green, G. M.

    1982-10-01

    The usefulness of lumped-parameter linear stability analyses for the prediction of dynamic instabilities of air cushion vehicles is explored. The configuration considered in detail is a single plenum chamber constrained to move in heave only and which is fed from a fan through a duct. The assumptions and equations typically used in such analyses are discussed and their applicability reviewed. An experiment designed to completely eliminate fan dynamic effects accurately reproduces the predictions of an earlier theoretical analysis of the effect of ducting of cushion stability. The existence of a very large duct effect is confirmed. An observed effect of the flow structure within the cushion volume on cushion stability is explained. Application of the theory to a configuration not specifically chosen to facilitate agreement between theory and experiment gives good qualitative agreement. It is concluded that, for systems of practical interest, accurate predictions of stability boundaries may be difficult. This is because, among other things, such predictions may require careful modelling of the dynamic behaviour of the fan, and incorporation of the effect of deformations of flexible skirts on cushion capacitance.

  9. Dynamic heave-pitch analysis of air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Captain, K. M.; Boghani, A. B.; Wormley, D. N.

    1975-01-01

    A program to develop analytical tools for evaluating the dynamic performance of Air Cushion Landing Systems (ACLS) is described. The heave (vertical) motion of the ACLS was analyzed, and the analysis was extended to cover coupled heave-pitch motions. The mathematical models developed are based on a fundamental analysis of the body dynamics and fluid mechanics of the aircraft-cushion-runway interaction. The air source characteristics, flow losses in the feeding ducts, trunk and cushion, the effects of fluid compressibility, and dynamic trunk deflections, including ground contact are considered. A computer program, based on the heave-pitch analysis, was developed to simulate the dynamic behavior of an ACLS during landing impact and taxi over an irregular runway. The program outputs include ACLS motions, loadings, pressures, and flows as a function of time. To illustrate program use, three basic types of simulations were carried out. The results provide an initial indication of ACLS performance during (1) a static drop, (2) landing impact, and (3) taxi over a runway irregularity.

  10. Reduced energy and volume air pump for a seat cushion

    DOEpatents

    Vaughn, Mark R. (Albuquerque, NM); Constantineau, Edward J. (Albuquerque, NM); Groves, Gordon E. (Tijeras, NM)

    1997-01-01

    An efficient pump system for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers.

  11. Reduced energy and volume air pump for a seat cushion

    DOEpatents

    Vaughn, M.R.; Constantineau, E.J.; Groves, G.E.

    1997-08-19

    An efficient pump system is described for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers. 12 figs.

  12. Human volunteer and anthropomorphic dummy tests of driver air cushion system.

    PubMed

    Smith, G R; Gulash, E C; Baker, R G

    1975-01-01

    The dynamic impact tests at Southwest Research Institute for the first time exposed human volunteers to production-like driver air cushion system depolyments at impact levels equivalent to a 30 mph barrier crash (48 kph). No significant injury was produced. At no time was it necessary for the secondary restraint systems to be utilized and the entire program schedule was carried out as planned. All tests were conducted under the most safe and controlled conditions possible, and typify only what the air cushions might accomplish in direct, head-on impacts up to 30 mph (48 kph). In comparing the test results, the anthropomorphic dummies' response to impact was conservative compared to the human volunteers. These and other human volunteer tests were run to help understand what might be expected in real world driving conditions. To further understand the value of this new safety system, 1000 1973 Chevrolets were built and places in a high mileage fleet across the couhtry. They now have accumulated 41 millions miles of experience and have had 15 accidents of sufficient severity that the air cushion depolyed. This fleet was followed with 1974 vehicles with air cushions sold to the general public as an option. These cars, combined with the test fleet, have accumulated approximately 60 million miles and have a total of 25 depolyments with 34 occupants in the front seat. There has been one fatality in accidents involving these vehicles, a seven week old baby boy. The child was not restrained in any protective carrier. All other injuries have been classified AIS-1 except for three AIS-2. Facial injuries have been very minimal and there have been no known hearing impairments as a result of these accident situations. To date, the results have been encouraging but caution must be taken in their interpretation. The population of drivers is not to be considered normal. The 60 million miles may appear to be a large number, but only represents 25 minutes of driving time of the total U.S. car population in 1 year. PMID:1116324

  13. A Comparison of the Average Sitting Pressures and Symmetry Indexes between Air-adjustable and Foam Cushions

    PubMed Central

    Kim, Won-Jin; Chang, Moonyoung

    2013-01-01

    [Purpose] The purpose of this study was to determine the best adjustable cushions, for the maintenance of normal sitting balance by healthy persons in wheelchairs, from a foam cushion, and a newly-developed air-adjustable cushion. [Subjects] Eighteen healthy participants (9 men, 9 women) were recruited. [Methods] Participants were evaluated using the Force Sensing Array System to assess average sitting pressure and the symmetry index of chair sitting under the following conditions: no seat cushion, a foam cushion, and a newly-developed air-adjustable cushion. [Results] The results show that there were no significant differences among the average sitting pressures which were measured on the hard surface of a chair, a foam cushion, and the newly-developed cushion. The air-adjustable cushion's symmetry index turned out to be closer to 0 than those of the foam cushion and the hard surface of the chair. [Conclusion] We suggest that the newly-developed air-adjustable cushion contributes to a more symmetrical sitting posture than the basic foam cushion or no seat cushion. PMID:24259942

  14. Effect of a Dynamic Air Cushion on the Development of Leg Edema during Wheelchair Sitting

    PubMed Central

    Murata, Jun; Murata, Shin; Ohyama, Michie; Kogo, Haruki; Matsubara, Shohzo

    2014-01-01

    [Purpose] To clarify how a novel dynamic cushion affects the leg edema evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with the dynamic air cushion or a static cushion. [Subjects and Methods] Nine healthy male subjects participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed around the middle portion of the lower thigh). Following a period of rest, each subject was asked to sit on a wheelchair containing the dynamic cushion for 15?min. Then, the protocol was repeated with a static cushion. The angles of the knee and ankle joints were set to 90 degrees, and no footrests were used. [Results] The change in leg volume observed during sitting on the dynamic cushion (0.00 0.03?mL/100?mL) was smaller than that observed during sitting on the static cushion (0.02 0.02?mL/100?mL). [Conclusion] These results suggested that the dynamic cushion relieved leg edema during wheelchair sitting. PMID:25013295

  15. Effect of a Dynamic Air Cushion on the Development of Leg Edema during Wheelchair Sitting.

    PubMed

    Murata, Jun; Murata, Shin; Ohyama, Michie; Kogo, Haruki; Matsubara, Shohzo

    2014-06-01

    [Purpose] To clarify how a novel dynamic cushion affects the leg edema evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with the dynamic air cushion or a static cushion. [Subjects and Methods] Nine healthy male subjects participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed around the middle portion of the lower thigh). Following a period of rest, each subject was asked to sit on a wheelchair containing the dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The angles of the knee and ankle joints were set to 90 degrees, and no footrests were used. [Results] The change in leg volume observed during sitting on the dynamic cushion (0.00 ± 0.03 mL/100 mL) was smaller than that observed during sitting on the static cushion (0.02 ± 0.02 mL/100 mL). [Conclusion] These results suggested that the dynamic cushion relieved leg edema during wheelchair sitting. PMID:25013295

  16. Effects of double air-cushion biofeedback exercises in a patient with sacroiliac joint pain.

    PubMed

    Yoo, Won-Gyu

    2015-11-01

    [Purpose] We developed a double air-cushion biofeedback device to be used for sacroiliac (SI) joint exercises and investigated the effects of exercising using the device in a patient with SI joint pain. [Subject] A 40-year-old man, who complained of pain in the left posterior iliac crest area and SI joints over a 6-month period participated. [Methods] After a 4-week exercise program using the double air-cushion biofeedback device, the subject was assessed using the Gaenslen, Patrick, posterior shear (POSH), and resisted abduction (REAB) tests. [Results] After performing exercise designed to strengthen subdivisions of the gluteus medius, the subject had no pain in the Gaenslen, Patrick, POSH, or REAB tests of the SI joint. The visual analog scale (VAS) score for pain on palpation of the left posterior iliac crest area decreased to 4/10 from an initial score of 7/10. [Conclusion] Exercises with the double air-cushion biofeedback device improved hip asymmetry, SI joint mobility, and muscle strength. PMID:26696747

  17. Effects of double air-cushion biofeedback exercises in a patient with sacroiliac joint pain

    PubMed Central

    Yoo, Won-gyu

    2015-01-01

    [Purpose] We developed a double air-cushion biofeedback device to be used for sacroiliac (SI) joint exercises and investigated the effects of exercising using the device in a patient with SI joint pain. [Subject] A 40-year-old man, who complained of pain in the left posterior iliac crest area and SI joints over a 6-month period participated. [Methods] After a 4-week exercise program using the double air-cushion biofeedback device, the subject was assessed using the Gaenslen, Patrick, posterior shear (POSH), and resisted abduction (REAB) tests. [Results] After performing exercise designed to strengthen subdivisions of the gluteus medius, the subject had no pain in the Gaenslen, Patrick, POSH, or REAB tests of the SI joint. The visual analog scale (VAS) score for pain on palpation of the left posterior iliac crest area decreased to 4/10 from an initial score of 7/10. [Conclusion] Exercises with the double air-cushion biofeedback device improved hip asymmetry, SI joint mobility, and muscle strength. PMID:26696747

  18. Speed control with end cushion for high speed air cylinder

    DOEpatents

    Stevens, Wayne W. (Idaho Falls, ID); Solbrig, Charles W. (Idaho Falls, ID)

    1991-01-01

    A high speed air cylinder in which the longitudinal movement of the piston within the air cylinder tube is controlled by pressurizing the air cylinder tube on the accelerating side of the piston and releasing pressure at a controlled rate on the decelerating side of the piston. The invention also includes a method for determining the pressure required on both the accelerating and decelerating sides of the piston to move the piston with a given load through a predetermined distance at the desired velocity, bringing the piston to rest safely without piston bounce at the end of its complete stroke.

  19. Fluid (Air/Water) Cushion Transportation Technology for Emplacing Heavy Canisters into Horizontal Disposal Drifts

    SciTech Connect

    Bosgiraud, J.M.; Seidler, W.K.; Londe, L.; Thurner, E.; Pettersson, S.

    2008-07-01

    The disposal of certain types of radioactive waste canisters in a deep repository involves handling and emplacement of very heavy loads. The weight of these particular canisters can be in the order of 20 to 50 metric tons. They generally have to be handled underground in openings that are not much larger than the canisters themselves as it is time consuming and expensive to excavate and backfill large openings in a repository. This therefore calls for the development of special technology that can meet the requirements for safe operation at an industrial scale in restrained operating spaces. Air/water cushion lifting systems are used world wide in the industry for moving heavy loads. However, until now the technology needed for emplacing heavy cylindrical radioactive waste packages in bored drifts (with narrow annular gaps) has not been previously developed or demonstrated. This paper describes the related R and D work carried out by ANDRA (for air cushion technology) and by SKB and Posiva (for water cushion technology) respectively, mainly within the framework of the European Commission (EC) funded Integrated Project called ESDRED (6. European Framework Programme). The background for both the air and the water cushion applications is presented. The specific characteristics of the two different emplacement concepts are also elaborated. Then the various phases of the Test Programmes (including the Prototype phases) are detailed and illustrated for the two lifting media. Conclusions are drawn for each system developed and evaluated. Finally, based on the R and D experience, improvements deemed necessary for an industrial application are listed. The tests performed so far have shown that the emplacement equipment developed is operating efficiently. However further tests are required to verify the availability and the reliability of the equipment over longer periods of time and to identify the modifications that would be needed for an industrial application in a nuclear and mining environment. (authors)

  20. Heave-pitch-roll analysis and testing of air cushion landing systems

    NASA Technical Reports Server (NTRS)

    Boghani, A. B.; Captain, K. M.; Wormley, D. N.

    1978-01-01

    The analytical tools (analysis and computer simulation) needed to explain and predict the dynamic operation of air cushion landing systems (ACLS) is described. The following tasks were performed: the development of improved analytical models for the fan and the trunk; formulation of a heave pitch roll analysis for the complete ACLS; development of a general purpose computer simulation to evaluate landing and taxi performance of an ACLS equipped aircraft; and the verification and refinement of the analysis by comparison with test data obtained through lab testing of a prototype cushion. Demonstration of simulation capabilities through typical landing and taxi simulation of an ACLS aircraft are given. Initial results show that fan dynamics have a major effect on system performance. Comparison with lab test data (zero forward speed) indicates that the analysis can predict most of the key static and dynamic parameters (pressure, deflection, acceleration, etc.) within a margin of a 10 to 25 percent.

  1. Air lifted and propelled vehicle

    SciTech Connect

    Jones, T.E.; Johnson, R.A.

    1987-02-17

    This patent describes a vehicle which rides on air cushion and which is propelled by air, comprising: upper deck means, having a bottom edge which defines the periphery of an area; a thin, flexible sheet located below the upper deck means, extending beneath the bottom edge and secured beneath the bottom edge for defining a plenum that is defined by and closed off by the upper deck means and the sheet. The deck means is shaped within the area defined by its bottom edge for causing the plenum to always be an open space and the upper deck means is rigid enough to maintain that open condition of the plenum; the sheet being secured in a manner permitting the sheet to pillow when air is pressurized in the plenum; and the sheet being perforated below the upper deck means for permitting exit of air from the plenum at a controllable rate through the perforations; the sheet having a large plurality of the perforations dispersed over most of its area below the upper deck means; each of the perforations being a hole.

  2. The Fluid-Structure Interaction in Supporting a Thin Flexible Cylindrical Web with AN Air Cushion

    NASA Astrophysics Data System (ADS)

    Müftü, S.; Cole, K. A.

    1999-08-01

    The mechanics of the fluid-structure interaction between a thin flexible web, wrapped around a cylindrical drum (reverser), and the air cushion formed by external pressurization through the holes of this drum is analyzed. Derivation of a ``new'' theory for the moderately large deflections of a thin cylindrical shell to model the web is presented. This theory allows for large web deflections, while using a self-adjusting strain-free reference state for the web in order to keep the circumferential web tension around a constant level. The theory also incorporates the redistribution of the in-plane stress resultants in the axial and shear directions using the Airy stress function. The air-flow is averaged over the height direction of the web-reverser clearance. The surface area of the pressure holes is averaged locally over the total reverser surface. The resulting equations are a modified form of the Navier-Stokes and mass balance equations with nonlinear source terms. The coupled fluid-structure system is solved numerically. The mechanics of the interaction between the web deflections and the air cushion generated by the reverser is explained. The effects of the problem parameters on the overall equilibrium are presented. Parameter distributions which cause the web to contact the reverser are identified, and suggestions are made to avoid this state.

  3. Numerical simulation of the flow in a conduit, in the presence of a confined air cushion

    NASA Astrophysics Data System (ADS)

    Nguyen, Trieu Dong

    1999-02-01

    A rectangular conduit with a closed end has water flowing in/out at the other end. The water level at the open end has an imposed sinusoidal movement. When this level is higher than the ceiling of the conduit, a certain mass of air is trapped under the ceiling. In a previous article (T.D. Nguyen, La Houille Blanche, No. 2, 1990), it was supposed that this air is flowing out freely through the ceiling, so the relative pressure at the water surface is zero, and the water hammer at the dead end of the conduit was calculated when the conduit was thoroughly filled. In this article, it is supposed that the trapped air is compressed isothermally or adiabatically. The set of equations is resolved (water continuity and movement equations, air state equation) by supposing a regime of flow at each section (section submerged or not), a certain value for the air pressure and by using the sweep method to determine the water flow characteristics. The air volume calculated by iteration must converge, and the calculated regimes at each section (submerged or free) must agree with the supposed regimes. The simulation is performed first with a horizontal conduit then with an inclined conduit. As expected, adiabatic compression gives higher pressure than isothermal compression. The simulation shows also that when there is an air cushion, compared with the case when air is flowing out freely, the shock of the water hammer at the closed end of the conduit is significantly reduced. This method is aimed at calculating the flow with entrapped air in the inlet/outlet tunnel of a hydroelectric plant, or in sewer system pipe when a sudden discharge surge (due to turbin opening/closing or to urban storm) changes a previously free-surface flow in a mostly full-pipe flow, but with some air entrapped under the ceiling. Copyright

  4. Effect of a responsive skirt on air cushion vehicle seakeeping

    NASA Astrophysics Data System (ADS)

    Zhou, W. L.; Ma, T.

    The skirt system, which will be excited to make a response motion under the outer disturbance, is treated as a passive control system, and the longitudinal motion equations of ACV are derived according to the control principle. The influence of the skirt response in waves on ACVs seaworthiness is analyzed in the paper. Some results are gotten that the greater vertical deflexion of skirt will make the response of heave, pitch motion and acceleration of the craft decreased a lot, but the horizontal deflexion will go the opposite way. The natural frequency of skirt plays an important role in seaworthiness improvement, the adoption of lower frequency skirt can make the frequency band of craft motion response narrower effectively. The matching of skirt parameters of bow and stern has a certain effect too.

  5. 1985 Joint International Conference on Air Cushion Technology, Rockville, MD, September 24-26, 1985, Preprints and Late Papers

    NASA Astrophysics Data System (ADS)

    Amyot, J. R.

    1985-12-01

    Papers are presented on the effect of a resonant skirt on ACV seakeeping, aerodynamic characteristics of a bag-cone skirt, and a calculation of the static forces acting on ACV bag-finger skirts. Also considered are tactical problems relating to the hovercraft application of marine gas turbines, development of the Air Cushion Equipment Transporter, prevention of propeller Foreign Object Damage, and air propellers and their environmental problems on ACVs. Other topics include the maneuvering simulation of an Antarctic hovercraft, computer-aided conceptual design of air ACVs, the use of model-test data for predicting full-scale ACV resistance, and passive control of air cushion heave dynamics. Papers are also presented on hovercraft in low enforcement, managing LCAC in the evolving acquisition environment, and SES and ACV for naval mission.

  6. Study on the stability of waterpower-speed control system for hydropower station with air cushion surge chamber

    NASA Astrophysics Data System (ADS)

    Guo, W. C.; Yang, J. D.; Chen, J. P.; Teng, Y.

    2014-03-01

    According to the fact that the effects of penstock, unit and governor on stability of water level fluctuation for hydropower station with air cushion surge chamber are neglected in previous researches, in this paper, Thoma assumption is broken through, the complete mathematical model of waterpower-speed control system for hydropower station with air cushion surge chamber is established, and the comprehensive transfer function and linear homogeneous differential equation that characterize the dynamic characteristics of system are derived. The stability domain that characterizes the good or bad of stability quantitatively is drawn by using the stability conditions. The effects of the fluid inertia in water diversion system, the air cushion surge chamber parameters, hydraulic turbine characteristics, generator characteristics, and regulation modes of governor on the stability of waterpower-speed control system are analyzed through stability domain. The main conclusions are as follows: The fluid inertia in water diversion system and hydraulic turbine characteristics have unfavorable effects on the system while generator characteristics have favorable effect. The stability keeps getting better with the increase of chamber height and basal area and the decrease of air pressure and air polytropic exponent. The stability of power regulation mode is obviously better than that of frequency regulation mode.

  7. A survey of protective cushion usage in individuals with spinal cord injury while traveling in a motor vehicle and on a commercial airliner

    PubMed Central

    McClure, Isa A.; Nieves, Jeremiah D.; Kirshblum, Steven C.

    2014-01-01

    Objective While there are specific recommendations for pressure relieving cushions when seated in a wheelchair, there is a paucity of information regarding prescribed wheelchair cushions for persons with spinal cord injury (SCI) when traveling and not in their wheelchair seat. A questionnaire was designed to ascertain if individuals with SCI who are primarily wheelchair users utilize a prescribed wheelchair cushion when traveling in a motor vehicle (MV) or on a commercial airliner, as not utilizing one may be a causative factor in developing pressure ulcers. Design and setting Survey design in an outpatient SCI rehabilitation setting. Participants Full-time wheelchair users, with chronic (>1 year) SCI. Results Forty-two participants completed the survey, with a mean age of 39 years old and time post-injury of 10.4 years. All subjects used a prescribed wheelchair cushion when seated in their wheelchair. Twenty-seven subjects reported transferring to a MV seat (59.5% of sample), with 25 (92.6%) reporting not using a prescribed wheelchair cushion when sitting directly on the MV seat. For subjects who traveled on an airplane (n=2354.8%), 19 (82.6%) reported that they do not sit on a prescribed specialty cushion. Conclusion Persons with chronic SCI, who are primary wheelchair users, utilize prescribed wheelchair cushions when sitting in their wheelchair, but most do not utilize a prescribed wheelchair cushion when seated in a MV (if they transfer out of their chair) or on a airplane seat. Studies to determine the pressures over the bony prominences on their travel surfaces may need to be undertaken to see whether the pressures are appropriate, as they may be a source of skin breakdown. PMID:24621043

  8. Modeling, simulation & optimization of the landing craft air cushion fleet readiness.

    SciTech Connect

    Engi, Dennis

    2006-10-01

    The Landing Craft Air Cushion is a high-speed, over-the-beach, fully amphibious landing craft capable of carrying a 60-75 ton payload. The LCAC fleet can serve to transport weapons systems, equipment, cargo and personnel from ship to shore and across the beach. This transport system is an integral part of our military arsenal and, as such, its readiness is an important consideration for our national security. Further, the best way to expend financial resources that have been allocated to maintain this fleet is a critical Issue. There is a clear coupling between the measure of Fleet Readiness as defined by the customer for this project and the information that is provided by Sandia's ProOpta methodology. Further, there is a richness in the data that provides even more value to the analyst. This report provides an analytic framework for understanding the connection between Fleet Readiness and the output provided by Sandia's ProOpta software. Further, this report highlights valuable information that can also be made available using the ProOpta output and concepts from basic probability theory. Finally, enabling assumptions along with areas that warrant consideration for further study are identified.

  9. Landing performance of an air cushion landing system installed on a 1/10-scale dynamic model on the C-8 Buffalo airplane

    NASA Technical Reports Server (NTRS)

    Thompson, W. C.

    1973-01-01

    An experimental study was conducted to evaluate the landing behavior of a 1/10-scale dynamic model of the C-8 Buffalo airplane equipped with an air-cushion landing system (ACLS) on a variety of surfaces including both calm and rough water and a smooth hard surface. Taxi runs were made on the hard surface over several obstacles. Landings were made with the model at various pitch and roll attitudes and vertical velocities and at one nominal horizontal velocity. Data from the landings include time histories of the trunk and air-cushion pressures and accelerations at selected locations on the model.

  10. Electric vehicle air conditioning

    SciTech Connect

    1996-09-01

    This article describes how optimizing accessories helps to extend electric vehicle range. A battery is the only source of energy available to power an electric vehicle (EV), so managing power consumption is critical to successful EV engineering. Accessories consuming electric power reduce the vehicle`s driving range. In the case of passenger compartment heating, available battery energy already is reduced at lower ambient temperatures. Minimizing power consumption of an EV climate control system, then, becomes a high priority in developing vehicles that are commercially acceptable.

  11. Landing impact studies of a 0.3-scale model air cushion landing system for a Navy fighter airplane

    NASA Technical Reports Server (NTRS)

    Leland, T. J. W.; Thompson, W. C.

    1975-01-01

    An experimental study was conducted in order to determine the landing-impact behavior of a 0.3-scale, dynamically (but not physically) similar model of a high-density Navy fighter equipped with an air cushion landing system. The model was tested over a range of landing contact attitudes at high forward speeds and sink rates on a specialized test fixture at the Langley aircraft landing loads and traction facility. The investigation indicated that vertical acceleration at landing impact was highly dependent on the pitch angle at ground contact, the higher acceleration of approximately 5g occurring near zero body-pitch attitude. A limited number of low-speed taxi tests were made in order to determine model stability characteristics. The model was found to have good pitch-damping characteristics but stability in roll was marginal.

  12. A Method to Keep Cushion Pressure under Control

    NASA Astrophysics Data System (ADS)

    Senba, Hiromitsu; Matsuo, Hideo; Matsuo, Kensuke; Kanazawa, Koji; Hiroe, Tetsuyuki; Fujiwara, Kazuhito

    An effective method to keep cushion pressure constant under fluctuation of cushion volume of SES is proposed and examined experimentally. In general, the fluctuation is induced by wave pumping. In the method an air jet with the length equal to the width of the air cushion is adapted. The air cushion is formed by this jet and sealed at one side. On the other hand, the opposite side is sealed with a material like as a skirt. The air nozzle that supplies the air jet can revolve to control the cushion pressure. In experiments a two-dimensional air cushion model of SES was used, where the wave pumping was simulated by a piston. Angle of the air nozzle was changed dynamically to eliminate the fluctuation of cushion pressure occurred by the piston. The experimental results show that the fluctuation of the cushion pressure became drastically extinct. The availability of this method was cleared and proved.

  13. Experimental and analytical dynamic flow characteristics of an axial-flow fan from an air cushion landing system model

    NASA Technical Reports Server (NTRS)

    Thompson, W. C.; Boghani, A. B.; Leland, T. J. W.

    1977-01-01

    An investigation was conducted to compare the steady-state and dynamic flow characteristics of an axial-flow fan which had been used previously as the air supply fan for some model air cushion landing system studies. Steady-state flow characteristics were determined in the standard manner by using differential orifice pressures for the flow regime from free flow to zero flow. In this same regime, a correlative technique was established so that fan inlet and outlet pressures could be used to measure dynamic flow as created by a rotating damper. Dynamic tests at damper frequencies up to 5 Hz showed very different flow characteristics when compared with steady-state flow, particularly with respect to peak pressures and the pressure-flow relationship at fan stall and unstall. A generalized, rational mathematical fan model was developed based on physical fan parameters and a steady-state flow characteristic. The model showed good correlation with experimental tests at damper frequencies up to 5 Hz.

  14. Foam Cushioning

    NASA Technical Reports Server (NTRS)

    1988-01-01

    One innovation developed by a contractor at Ames Research Center was an open cell polymeric foam material with unusual properties. Intended as padding for aircraft seats the material offered better impact protection against accidents, and also enhanced passenger comfort because it distributed body weight evenly over the entire contact area. Called a slow springback foam, it flows to match the contour of the body pressing against it, and returns to its original shape once the pressure is removed. It has many applications including aircraft cushions and padding, dental stools, and athletic equipment. Now it's used by Dynamic Systems, Inc. for medical applications such as wheel chairs for severely disabled people which allow them to sit for 3-8 hours where they used to be uncomfortable in 15-30 minutes.

  15. A Computer Modeling Study to Evaluate the Potential Effect of Air Cell-based Cushions on the Tissues of Bariatric and Diabetic Patients.

    PubMed

    Levy, Ayelet; Kopplin, Kara; Gefen, Amit

    2016-01-01

    Sitting-acquired pressure ulcers (PUs) are a potentially life-endangering complication for wheelchair users who are obese and have diabetes mellitus. The increased body weight and diabetes-related alterations in weight-bearing tissue properties have been identified in the literature to increase the risk for PUs and deep tissue injuries (DTIs). A computer modeling study was conducted to evaluate the biomechanical effect of an air cell-based (ACB) cushion on tissues with increased fat mass and diabetes, which causes altered stiffness properties in connective tissues with respect to healthy tissues. Specifically, 10 finite element (FE) computer simulations were developed with the strain and stress distributions and localized magnitudes considered as measures of the theoretical risk for PUs and DTIs to assess the effects of fat mass and pathological tissue properties on the effective strains and stresses in the soft tissues of buttocks during sitting on an ACB cushion. The FE modeling captured the anatomy of a seated buttocks acquired in an open magnetic resonance imaging examination of an individual with a spinal cord injury. The ACB cushion facilitated a moderate increase in muscle strains (up to 15%) and stresses (up to 30%), and likewise a moderate increase in size of the affected tissue areas with the increase in fat mass, for both diabetic and nondiabetic conditions. These simulation results suggest wheelchair users who are obese and have diabetes may benefit from using an ACB to minimize the increased mechanical strains and stresses in the weight-bearing soft tissues in the buttocks that result from these conditions. Clinical studies to increase understanding about the risk factors of both obesity and diabetes mellitus for the development of PUs and DTIs, as well as robust preclinical comparative studies, may provide much-needed evidence to help clinicians make informed PU prevention and wheelchair cushion decisions for this patient population and other wheelchair-bound individuals. PMID:26779701

  16. Intelligence Applied to Air Vehicles

    NASA Technical Reports Server (NTRS)

    Rosen, Robert; Gross, Anthony R.; Fletcher, L. Skip; Zornetzer, Steven (Technical Monitor)

    2000-01-01

    The exponential growth in information technology has provided the potential for air vehicle capabilities that were previously unavailable to mission and vehicle designers. The increasing capabilities of computer hardware and software, including new developments such as neural networks, provide a new balance of work between humans and machines. This paper will describe several NASA projects, and review results and conclusions from ground and flight investigations where vehicle intelligence was developed and applied to aeronautical and space systems. In the first example, flight results from a neural network flight control demonstration will be reviewed. Using, a highly-modified F-15 aircraft, a NASA/Dryden experimental flight test program has demonstrated how the neural network software can correctly identify and respond to changes in aircraft stability and control characteristics. Using its on-line learning capability, the neural net software would identify that something in the vehicle has changed, then reconfigure the flight control computer system to adapt to those changes. The results of the Remote Agent software project will be presented. This capability will reduce the cost of future spacecraft operations as computers become "thinking" partners along with humans. In addition, the paper will describe the objectives and plans for the autonomous airplane program and the autonomous rotorcraft project. Technologies will also be developed.

  17. Effect of seat cushions on human response to +Gz impact.

    PubMed

    Hearon, B F; Brinkley, J W

    1986-02-01

    Human response to vertical (+Gz) impact acceleration was evaluated as a function of various seat cushions, including current operational cushions used in such aircraft as the A-10, F-15, and F-111 and proposed alternative cushions comprised of rate-dependent, slow-recovery polyurethane foams. There were 133 tests conducted of volunteer subjects in seven different experimental conditions, using a vertical deceleration tower facility. The mean peak acceleration of the impact carriage for these tests was 9.85 G (S.D. = 0.07) and the mean carriage velocity change was 8.01 m X s-1 (S.D. = 0.05). Resultant seat loads and head and chest accelerations were significantly higher for the F-111 cushion than for the rate-dependent foam cushions, which included cushions comprised of Confor foam or Temper foam. Resultant head and chest accelerations were also significantly higher for the ACES II cushion than for the rate-dependent foam cushions. Therefore, from an impact protection standpoint, the operational cushions were inferior to the proposed alternative cushions. Operational use of rate-dependent foam cushions is recommended to improve the impact protection performance of escape systems. Flight tests conducted by the USAF Strategic Air Command have shown that these cushions enhance crewmember sitting comfort during long-duration missions. PMID:3954698

  18. Introduction of the air cushion vehicle 'Larus' to the North American market

    NASA Astrophysics Data System (ADS)

    Makinen, E.; Wainwright, J.

    The 'Larus' ACV, which currently operates as a ferry in the Northern Baltic with a payload of 25 tonnes and 46 passengers, will be refurbished for operations in the Canadian Arctic. These modifications will encompass the incorporation of an Arctic-grade rubber skirt, additional fire and thermal insulation, more heating and washrooms for passenger compartments, a fire extinghuishing system, a second radar unit, and satellite navigation. A development history and performance evaluation of the Larus are given.

  19. Aerodynamics for Revolutionary Air Vehicles

    NASA Technical Reports Server (NTRS)

    Sellers, William L., III; Singer, Bart A.; Leavitt, Laurence D.

    2003-01-01

    Aeronautics research has seriously declined partly because of the perception that it is a mature science and only incremental improvements are possible. Recent aeronautics roadmapping activities at NASA Langley paint a different picture of the future. Breakthroughs are still felt to be possible if we expand the current design space of today's vehicles and optimize the airspace and vehicles as a system. The paper describes some of the challenges that the aircraft and airline industry face. These challenges include political, technical and environmental issues. Examples of the opportunities and technologies that could provide a different vision for the future are discussed.

  20. Flexible-Wing-Based Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Jenkins, David A.; Ettinger, Scott; Lian, Yong-Sheng; Shyy, Wei; Waszak, Martin R.

    2002-01-01

    This paper documents the development and evaluation of an original flexible-wing-based Micro Air Vehicle (MAV) technology that reduces adverse effects of gusty wind conditions and unsteady aerodynamics, exhibits desirable flight stability, and enhances structural durability. The flexible wing concept has been demonstrated on aircraft with wingspans ranging from 18 inches to 5 inches. Salient features of the flexible-wing-based MAV, including the vehicle concept, flexible wing design, novel fabrication methods, aerodynamic assessment, and flight data analysis are presented.

  1. Covert air vehicle 2003 LDRD final report.

    SciTech Connect

    Spletzer, Barry Louis; Callow, Diane Schafer; Salton, Jonathan Robert; Fischer, Gary John

    2003-11-01

    This report describes the technical work carried out under a 2003 Laboratory Directed Research and Development project to develop a covert air vehicle. A mesoscale air vehicle that mimics a bird offers exceptional mobility and the possibility of remaining undetected during flight. Although some such vehicles exist, they are lacking in key areas: unassisted landing and launching, true mimicry of bird flight to remain covert, and a flapping flight time of any real duration. Current mainstream technology does not have the energy or power density necessary to achieve bird like flight for any meaningful length of time; however, Sandia has unique combustion powered linear actuators with the unprecedented high energy and power density needed for bird like flight. The small-scale, high-pressure valves and small-scale ignition to make this work have been developed at Sandia. We will study the feasibility of using this to achieve vehicle takeoff and wing flapping for sustained flight. This type of vehicle has broad applications for reconnaissance and communications networks, and could prove invaluable for military and intelligence operations throughout the world. Initial tests were conducted on scaled versions of the combustion-powered linear actuator. The tests results showed that heat transfer and friction effects dominate the combustion process at 'bird-like' sizes. The problems associated with micro-combustion must be solved before a true bird-like ornithopter can be developed.

  2. Analysis for SNF Multi Canister Overpack (MCO) Drop into the Cask from the MCO Handling Machine (MHM) with Air Cushion

    SciTech Connect

    RAINS, D.J.

    2000-01-12

    The purpose of this report is to investigate the potential for damage to the MCO during impact from an accidental drop from the MHM into the shipping cask. The MCO is dropped from a height of 8.2 feet above the cask enters the cask concentrically and falls the additional 12.83 feet to the cask bottom. Because of the interface fit between the MCO and the cask and the air entrapment the MCO fall velocity is slowed. The shipping cask is resting on an impact absorber at the time of impact. The energy absorbing properties of the impact absorber are included in this analysis.

  3. Autonomous unmanned air vehicles (UAV) techniques

    NASA Astrophysics Data System (ADS)

    Hsu, Ming-Kai; Lee, Ting N.

    2007-04-01

    The UAVs (Unmanned Air Vehicles) have great potentials in different civilian applications, such as oil pipeline surveillance, precision farming, forest fire fighting (yearly), search and rescue, boarder patrol, etc. The related industries of UAVs can create billions of dollars for each year. However, the road block of adopting UAVs is that it is against FAA (Federal Aviation Administration) and ATC (Air Traffic Control) regulations. In this paper, we have reviewed the latest technologies and researches on UAV navigation and obstacle avoidance. We have purposed a system design of Jittering Mosaic Image Processing (JMIP) with stereo vision and optical flow to fulfill the functionalities of autonomous UAVs.

  4. A seat cushion to provide realistic acceleration cues for aircraft simulators

    NASA Technical Reports Server (NTRS)

    Ashworth, B. R.

    1976-01-01

    A seat cushion to provide acceleration cues for aircraft simulator pilots was built, performance tested, and evaluated. The four cell seat, using a thin air cushion with highly responsive pressure control, attempts to reproduce the same events which occur in an aircraft seat under acceleration loading. The pressure controller provides seat cushion responses which are considered adequate for current high performance aircraft simulations. The initial tests of the seat cushions have resulted in excellent pilot opinion of the cushion's ability to provide realistic and useful cues to the simulator pilot.

  5. Motor Vehicles, Air Pollution, and Climate Change

    NASA Astrophysics Data System (ADS)

    Mark, Jason

    2000-04-01

    Despite years of technical progress, motor vehicles continue to be a leading cause of environmental damage in the United States. For example, today's cars and trucks are the largest source of air pollution in many urban areas. US motor vehicles also account for 25 percent of the nation's carbon emissions, more than most countries emit from all sources combined. Fortunately, a host of technical improvements are emerging that could go a long ways towards taking vehicles out of the pollution picture. In the near-term, improving on the century-old internal combustion engine can deliver much-needed incremental gains. But electric drive vehicles--whether powered by batteries, small engines in hybrid configuration, or fuel cells--ultimately offer the greatest promise. Such technologies could dramatically reduce energy use, greenhouse gas emissions, and key air pollutants. The bulk of technical attention in recent years has been focused on improving the passenger vehicle, which will be the dominant energy consumer in the transportation sector for years to come. But freight trucks are also of growing concern, both because their contribution to global warming is on the rise and because serious questions are being raised about the public health impact of diesel technology. As a result, heavy trucks are emerging as a priority issue. Capitalizing on the opportunity presented by new technologies will not only require continued technical innovation but also policy action. As research into improved engines, fuels, and drive systems bears fruit over the coming years, aggressive and prudent policies will ensure that these new options make it onto the road and deliver on their environmental promise.

  6. Impact of Vehicle Air-Conditioning on Fuel Economy, Tailpipe Emissions, and Electric Vehicle Range: Preprint

    SciTech Connect

    Farrington, R.; Rugh, J.

    2000-09-22

    Vehicle air-conditioning can significantly impact fuel economy and tailpipe emissions of conventional and hybrid electric vehicles and reduce electric vehicle range. In addition, a new US emissions procedure, called the Supplemental Federal Test Procedure, has provided the motivation for reducing the size of vehicle air-conditioning systems in the US. The SFTP will measure tailpipe emissions with the air-conditioning system operating. Current air-conditioning systems can reduce the fuel economy of high fuel-economy vehicles by about 50% and reduce the fuel economy of today's mid-sized vehicles by more than 20% while increasing NOx by nearly 80% and CO by 70%.

  7. Integrated photonic systems redefine air vehicle management

    NASA Astrophysics Data System (ADS)

    Francis, David L.; Fazi, Floyd A., Jr.

    2001-06-01

    Future military aircraft will be taking advantage of advances in optical information networks. Fly by Light will encompass not only using commercially based databus networks between processors but also incorporating purely optical sensors and transducers. Several types of optical transducers are available and have been demonstrated for feedback and health monitoring. Integration techniques that include optical tunable filters, high-speed switches, cross- connect switches, multiplexers and demultiplexers operating in the 1550-nm band have been demonstrated. This integrated approach shows the potential to reduce weight, increase bandwidth and improve supportability for production air vehicles.

  8. Viscoelastic cushion for patient support

    NASA Technical Reports Server (NTRS)

    Sauers, D. G.

    1971-01-01

    Flexible container, filled with liquid, provides supportive device which conforms to patient's anatomy. Uniform cushion pressure prevents formation of decubitus ulcers, while the porous sponge substructure damps fluid movement through cushion response so that patient is not dumped when his weight shifts.

  9. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.A.; Merry, G.W. )

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  10. Air-Conditioning for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Popinski, Z.

    1984-01-01

    Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

  11. Effects of different seat cushions on interface pressure distribution: a pilot study

    PubMed Central

    Lee, Sang-Heon; Park, Ji-Su; Jung, Bong-Keun; Lee, Sung-A

    2016-01-01

    [Purpose] The purpose of this study was to evaluate pressure redistribution on the supporting area of healthy volunteers when using different cushions. [Subjects and Methods] Twenty healthy individuals ranging in age from 19–23 years old and 20 older adults age 60 or above participated in the study. All participants lived in urban communities in South Korea. Group differences according to gender, age, and cushion types were analyzed with one-way analysis of variance and post-hoc analysis. [Results] Statistically significant differences in peak pressure and mean pressure were identified between age, gender, and cushion types. Peak pressure and mean pressure were higher on firm surfaces and on the air cushion than other cushion types. The pressure ratio was lower when an air cushion was used in the buttock area and was higher when it was used under the thighs compared to that in other conditions. [Conclusion] This study showed that interface pressure can be distributed differently depending on what cushions are used. Therefore, when using seat cushions, individuals should seek advice to help them choose the appropriate cushion for their needs. PMID:26957763

  12. Zinc air battery development for electric vehicles

    NASA Astrophysics Data System (ADS)

    Putt, Ronald A.

    1990-05-01

    This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal foam substrate for the zinc electrode, in combination with forced convection of electrolyte through the foam during battery operation. Research at LBL showed promise that this approach would avoid shape change (densification and dendrite growth), the primary failure mode of this electrode. The program comprised five tasks: (1) cell design, (2) capacity maximization, (3) cycle testing, (4) materials qualification, and (5) a cost/design study. The cell design contemplates a plate and frame stack, with alternating zinc and oxygen electrode frame assemblies between rigid end plates. A 200 Ah cell, as may be required for the EV application, would comprise a stack of five zinc and six oxygen electrode frame/assemblies.

  13. Development of a low-cost crash cushion using recycled automobile tires. Final report

    SciTech Connect

    Habors, D.T.; Hossain, M.

    1998-09-01

    Approximately thirty percent of all vehicle related fatalities that occur each year caused by a single vehicle leaving the road and striking a fixed object; the most common objects struck being trees, guardrails, and utility poles. In many cases current crash cushion systems are not cost effective to be installed on such obstacles. In addition to high initial costs many crash cushions require extensive maintenance or expensive replacement parts driving costs up even more. This makes the development of a more cost-effective crash cushion a necessity. This study proposed an initial design for a low-cost, reusable crash cushion using recycled materials. Used tires and tire-derived materials were tested in both static and dynamic modes to evaluate their application in a crash cushion. Both proved to be able to sustain high loads and durable, making them good candidates for use in a crash cushion. However, the tire-derived pads had excessively high loads per unit deflection prohibiting their use in a crash cushion. This problem could be eliminated if voids were added to allow material to deflect more under loading. The used tires could be used effectively as energy absorbing elements in crash cushions or truck mounted attenuators (TMA`s) if compressed horizontally or vertically.

  14. Seat cushion to provide realistic acceleration cues to aircraft simulator pilot

    NASA Technical Reports Server (NTRS)

    Ashworth, B. R. (Inventor)

    1979-01-01

    Seat cushions, each including an air cell with a non-compressible surface, are disclosed. The apparatus are provided for initially controlling the air pressure in the air cells to allow the two main support areas of the simulator pilot to touch the non-compressible surface and thus begin to compress the flesh near these areas. During a simulated flight the apparatus control the air pressure in the cells to simulate the events that occur in a seat cushion during actual flight.

  15. Aircraft Seat Cushion Fire-Blocking Layers

    NASA Technical Reports Server (NTRS)

    Schutter, Kenneth J.; Duskin, Fred E.; Trabold, Edward L.

    1987-01-01

    229-page report describes work done to determine burning characteristics of present and proposed seat-cushion materials and types of construction. Tested cushions classified in four groups: standard cushion construction, standard cushion construction with protective covering enveloping urethane-foam core, standard cushion construction with protective covering enveloping non-fire-retarded urethane-foam core, and standard cushion construction with urethane-foam core replaced by advanced fire-resistant foam. Report includes still photographs and presents quantitative data from each test in graphs and tables.

  16. Interior view Beale Air Force Base, Perimeter Acquisition Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  17. Looking north Beale Air Force Base, Perimeter Acquisition Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking north - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  18. Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle Refueling Station, Northeast of AGE Storage Facility at far northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  19. Robotic air vehicle. Blending artificial intelligence with conventional software

    NASA Technical Reports Server (NTRS)

    Mcnulty, Christa; Graham, Joyce; Roewer, Paul

    1987-01-01

    The Robotic Air Vehicle (RAV) system is described. The program's objectives were to design, implement, and demonstrate cooperating expert systems for piloting robotic air vehicles. The development of this system merges conventional programming used in passive navigation with Artificial Intelligence techniques such as voice recognition, spatial reasoning, and expert systems. The individual components of the RAV system are discussed as well as their interactions with each other and how they operate as a system.

  20. Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings

    PubMed Central

    Slegers, Nathan

    2014-01-01

    Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system. PMID:24516368

  1. Gust mitigation of micro air vehicles using passive articulated wings.

    PubMed

    Oduyela, Adetunji; Slegers, Nathan

    2014-01-01

    Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system. PMID:24516368

  2. Multiple Unmanned Air Vehicles Control Using Neurobiologically Inspired Algorithms

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Wang, Li

    In order to develop and evaluate future Unmanned Air Vehicles for the hazardous environmental monitoring, the comprehensive simulation test and analysis of new advanced concepts is imperative. This paper details an on-going proof of concept focused on development of a neurobiologically-inspired system for the high level control of a Air Vehicle team. This study, entitled Neurobiologically Enabled Autonomous Vehicle Operations, will evaluate initial System-Under-Test concept data by selecting well defined tasks, and evaluating performance based on assignment effectiveness, cooperation, and adaptability of the system. The system will be tested thoroughly in simulation, and if mature, will be implemented in hardware.

  3. Honeywell's organic air vehicle chemical-biological sensing platform

    NASA Astrophysics Data System (ADS)

    Cole, Barry E.; Krafthefer, Brian; Knee, Daniel; Fulton, Vaughn M.; Law, Kristen

    2004-12-01

    Unmanned air vehicles (UAVs) today are mostly used for reconnaissance and sometimes weapons delivery. Remote sensing of chemical-biological (CB) agents is another beneficial use of UAVs. While remote sensing of CB agents can be done by LIDAR spectroscopy, this technology is less spatially precise and less sensitive than actual measurements on a collected sample. One family of UAVs of particularly unique benefit for CB sampling and in-flight analysis is the Honeywell family of Organic Air Vehicles (OAVs). This vehicle with its ability to hover and stare has the unique ability among UAVs to collect and analyze chem-bio samples from a specific location over extended periods of time. Such collections are not possible with other micro-air-vehicles (MAVs) that only operate in fly-by mode. This paper describes some of the Honeywell OAV features that are conducive to CB detection.

  4. 78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... AGENCY 40 CFR Part 80 RIN 2060-AQ86 Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle... hearings to be held for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule is hereinafter referred to as ``Tier 3''),...

  5. Missions and vehicle concepts for modern, propelled, lighter-than-air vehicles

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1984-01-01

    The results of studies conducted over the last 15 years to assess missions and vehicle concepts for modern, propelled, lighter-than-air vehicles (airships) were surveyed. Rigid and non-rigid airship concepts are considered. The use of airships for ocean patrol and surveillance is discussed along with vertical heavy lift airships. Military and civilian needs for high altitude platforms are addressed.

  6. Assessment on motor vehicle emissions and air quality in Beijing

    SciTech Connect

    Lixin Fu; Jiming Hao; Kebin He; Dongquan He

    1996-12-31

    It is occasionally reported that hourly ozone concentrations exceed the National Air Quality Standard (NAQS) of China in recent years in Beijing, which indicates that motor vehicle emissions are more and more important to the total air quality in urban area of Beijing. A deep investigation was carried out to collect the information on road status, vehicle number and types, fuel consumption, traffic condition, and vehicle management in Beijing, so that the real world emission factors (CO, HC, NO{sub x}) could be calculated by MOBILE5a model. The calculated results were comparable with limited testing data from other former researches. With a detailed survey on emissions from other sources such as oil refueling, plants HC emission, and other stationary sources, the emission inventory are established and further projected for the future years, thus the emission contribution rates are obtained for motor vehicle emissions. The results are given for different seasons and different areas in Beijing.

  7. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    SciTech Connect

    Norman, Kevin M; Huff, Shean P; West, Brian H

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in fuel economy with increasing restriction. However, the level of restriction required to cause a substantial (10-15%) decrease in fuel economy (such as that cited in the literature) was so severe that the vehicle was almost undrivable. Acceleration performance on all vehicles was improved with a clean air filter. Once it was determined how severe the restriction had to be to affect the carbureted vehicle fuel economy, the 2007 Buick Lucerne was retested in a similar manner. We were not able to achieve the level of restriction that was achieved with the 1972 Pontiac with the Lucerne. The Lucerne's air filter box would not hold the filter in place under such severe conditions. (It is believed that this testing exceeded the design limits of the air box.) Tests were conducted at a lower restriction level (although still considerably more severe than the initial clogged filter testing), allowing the air filter to stay seated in the air box, and no significant change was observed in the Lucerne's fuel economy or the AFR over the HFET cycle. Closed-loop control in modern fuel injected vehicle applications is sophisticated enough to keep a clogged air filter from affecting the vehicle fuel economy. However for older, open-loop, carbureted vehicles, a clogged air filter can affect the fuel economy. For the vehicle tested, the fuel economy with a new air filter improved as much as 14% over that with a severely clogged filter (in which the filter was so clogged that drivability was impacted). Under a more typical state of clog, the improvement with a new filter ranged from 2 to 6%.

  8. Prototype air bag restraint for use in patrol vehicles

    SciTech Connect

    Marts, D.J.; Barker, S.G.

    1995-03-01

    An air bag has been designed and laboratory tested for use in existing police vehicles that will restrain a person if he or she becomes violent. The device will prevent self-injury and protect the vehicle and officer. The device does not pose a suffocation hazard and can be quickly and easily inflated or deflated by the officer from the front seat. The device is ready for field testing.

  9. Air change rates of motor vehicles and in-vehicle pollutant concentrations from secondhand smoke.

    PubMed

    Ott, Wayne; Klepeis, Neil; Switzer, Paul

    2008-05-01

    The air change rates of motor vehicles are relevant to the sheltering effect from air pollutants entering from outside a vehicle and also to the interior concentrations from any sources inside its passenger compartment. We made more than 100 air change rate measurements on four motor vehicles under moving and stationary conditions; we also measured the carbon monoxide (CO) and fine particle (PM(2.5)) decay rates from 14 cigarettes smoked inside the vehicle. With the vehicle stationary and the fan off, the ventilation rate in air changes per hour (ACH) was less than 1 h(-1) with the windows closed and increased to 6.5 h(-1) with one window fully opened. The vehicle speed, window position, ventilation system, and air conditioner setting was found to affect the ACH. For closed windows and passive ventilation (fan off and no recirculation), the ACH was linearly related to the vehicle speed over the range from 15 to 72 mph (25 to 116 km h(-1)). With a vehicle moving, windows closed, and the ventilation system off (or the air conditioner set to AC Max), the ACH was less than 6.6 h(-1) for speeds ranging from 20 to 72 mph (32 to 116 km h(-1)). Opening a single window by 3'' (7.6 cm) increased the ACH by 8-16 times. For the 14 cigarettes smoked in vehicles, the deposition rate k and the air change rate a were correlated, following the equation k=1.3a (R(2)=82%; n=14). With recirculation on (or AC Max) and closed windows, the interior PM(2.5) concentration exceeded 2000 microg m(-3) momentarily for all cigarettes tested, regardless of speed. The concentration time series measured inside the vehicle followed the mathematical solutions of the indoor mass balance model, and the 24-h average personal exposure to PM(2.5) could exceed 35 microg m(-3) for just two cigarettes smoked inside the vehicle. PMID:17637707

  10. Yaw rate control of an air bearing vehicle

    NASA Technical Reports Server (NTRS)

    Walcott, Bruce L.

    1989-01-01

    The results of a 6 week project which focused on the problem of controlling the yaw (rotational) rate the air bearing vehicle used on NASA's flat floor facility are summarized. Contained within is a listing of the equipment available for task completion and an evaluation of the suitability of this equipment. The identification (modeling) process of the air bearing vehicle is detailed as well as the subsequent closed-loop control strategy. The effectiveness of the solution is discussed and further recommendations are included.

  11. Unmanned Air Vehicle -Version 1.0

    Energy Science and Technology Software Center (ESTSC)

    2013-04-17

    This package contains modules that model the mobility of systems such as helicopters and fixed wing flying in the air. This package currently models first order physics - basically a velocity integrator. UAV mobility uses an internal clock to maintain stable, high-fidelity simulations over large time steps This package depends on interface that reside in the Mobility package.

  12. Air-Breathing Launch Vehicle Technology Being Developed

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    2003-01-01

    Of the technical factors that would contribute to lowering the cost of space access, reusability has high potential. The primary objective of the GTX program is to determine whether or not air-breathing propulsion can enable reusable single-stage-to-orbit (SSTO) operations. The approach is based on maturation of a reference vehicle design with focus on the integration and flight-weight construction of its air-breathing rocket-based combined-cycle (RBCC) propulsion system.

  13. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D. , Inc., Cambridge, MA )

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an [open quotes]upsized[close quotes] condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  14. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D.

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an {open_quotes}upsized{close_quotes} condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  15. Flush Air Data Sensing System for Trans-Atmospheric Vehicles

    NASA Astrophysics Data System (ADS)

    Ellsworth, Joel

    2006-10-01

    With the emergence of multiple companies attempting to tap the space tourism market, as well as NASA's return to the moon initiative, an inexpensive but reliable means of determining wind relative vehicle attitude is becoming a necessity. The traditional means of obtaining air data (altitude, Mach number, angles of attack and sideslip) using fixed pitot probes and directional flow vanes is not viable for collecting data on high supersonic and hypersonic vehicles, due to the high temperatures and dynamic pressures. The solution is to use a matrix of flush mounted pressure ports on the vehicle nose or on an outboard wing leading edge. Since the ports will be located behind a detached shock wave at supersonic velocities, the temperatures will remain substantially lower. A Flush Air Data Sensing (FADS) system can also be used for subsonic conditions, although it must be calibrated for the effects of the vehicle geometry. The physics of air behavior and the mathematics of the solution algorithm will be presented. Several relevant examples of planned vehicles will be presented.

  16. Mechanically refuelable zinc/air electric vehicle cells

    NASA Astrophysics Data System (ADS)

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  17. Development of vehicle magnetic air conditioner (VMAC) technology. Final report

    SciTech Connect

    Gschneidner, Karl A., Jr.; Pecharsky, V.K.; Jiles, David; Zimm, Carl B.

    2001-08-28

    The objective of Phase I was to explore the feasibility of the development of a new solid state refrigeration technology - magnetic refrigeration - in order to reduce power consumption of a vehicle air conditioner by 30%. The feasibility study was performed at Iowa State University (ISU) together with Astronautics Corporation of America Technology Center (ACATC), Madison, WI, through a subcontract with ISU.

  18. A zinc-air battery and flywheel zero emission vehicle

    SciTech Connect

    Tokarz, F.; Smith, J.R.; Cooper, J.; Bender, D.; Aceves, S.

    1995-10-03

    In response to the 1990 Clean Air Act, the California Air Resources Board (CARB) developed a compliance plan known as the Low Emission Vehicle Program. An integral part of that program was a sales mandate to the top seven automobile manufacturers requiring the percentage of Zero Emission Vehicles (ZEVs) sold in California to be 2% in 1998, 5% in 2001 and 10% by 2003. Currently available ZEV technology will probably not meet customer demand for range and moderate cost. A potential option to meet the CARB mandate is to use two Lawrence Livermore National Laboratory (LLNL) technologies, namely, zinc-air refuelable batteries (ZARBs) and electromechanical batteries (EMBs, i. e., flywheels) to develop a ZEV with a 384 kilometer (240 mile) urban range. This vehicle uses a 40 kW, 70 kWh ZARB for energy storage combined with a 102 kW, 0.5 kWh EMB for power peaking. These technologies are sufficiently near-term and cost-effective to plausibly be in production by the 1999-2001 time frame for stationary and initial vehicular applications. Unlike many other ZEVs currently being developed by industry, our proposed ZEV has range, acceleration, and size consistent with larger conventional passenger vehicles available today. Our life-cycle cost projections for this technology are lower than for Pb-acid battery ZEVs. We have used our Hybrid Vehicle Evaluation Code (HVEC) to simulate the performance of the vehicle and to size the various components. The use of conservative subsystem performance parameters and the resulting vehicle performance are discussed in detail.

  19. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, James M. (Albuquerque, NM); Luna, Daniel A. (Los Lunas, NM); Gwinn, Kenneth W. (Cedar Crest, NM)

    1997-01-01

    An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening.

  20. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, James M. (Albuquerque, NM); Luna, Daniel A. (Los Lunas, NM); Gwinn, Kenneth W. (Cedar Crest, NM)

    1998-01-01

    An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening.

  1. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles ...

  2. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles ...

  3. Prospects for future hypersonic air-breathing vehicles

    NASA Technical Reports Server (NTRS)

    Beach, H. L., Jr.; Blankson, Isaiah M.

    1991-01-01

    The age of hypersonics is (almost) here. This is evident from the amount of activity in the United States, Europe, the USSR and Japan; this activity is a reflection of technical progress in key areas which will enable new vehicle systems, as well as renewed interest in the utilization of these systems. The current situation, at least in the United States, is the product of an interesting history which is briefly reviewed here. The context for hypersonic applications is discussed, but the emphasis is on hypersonic technology issues and needs, particularly for propulsion and technology integration. The paper concludes with prospects for accomplishing the objective of air-breathing hypersonic vehicle systems.

  4. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  5. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  6. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  7. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  8. 21 CFR 890.3175 - Flotation cushion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Flotation cushion. 890.3175 Section 890.3175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion....

  9. In-vehicle particle air pollution and its mitigation

    NASA Astrophysics Data System (ADS)

    Tartakovsky, L.; Baibikov, V.; Czerwinski, J.; Gutman, M.; Kasper, M.; Popescu, D.; Veinblat, M.; Zvirin, Y.

    2013-01-01

    This work presents results of particle mass, number and size measurements inside passenger cars (PCs), vans and urban buses. Effects of the in-cabin air purifier on particle concentrations and average size inside a vehicle are studied. Use of the air purifier leads to a dramatic reduction, by 95-99%, in the measured ultrafine particles number concentration inside a vehicle compared with outside readings. Extremely low particle concentrations may be reached without a danger of vehicle occupants' exposure to elevated CO2 levels. The lowest values of particle concentrations inside a PC without air purifier are registered under the recirculation ventilation mode, but the issue of CO2 accumulation limits the use of this mode to very short driving events. Lower PM concentrations are found inside newer cars, if this ventilation mode is used. Great differences by a factor of 2.5-3 in PM10 concentrations are found between the PCs and the buses. Smoking inside a car leads to a dramatic increase, by approximately 90 times, in PM2.5 concentrations.

  10. Air liquefaction and enrichment system propulsion in reusable launch vehicles

    SciTech Connect

    Bond, W.H.; Yi, A.C.

    1994-07-01

    A concept is shown for a fully reusable, Earth-to-orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high-speed acceleration, both using liquid hydrogen for fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90% pure liquid oxygen as its oxidizer that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. This article shows an approach and the corresponding technology needs for using air liquefaction and enrichment system propulsion in a single-stage-to-orbit (SSTO) vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, in a direct substitution for aluminum or aluminum-lithium alloy, is critical to meet the structure weight objective for SSTO. Configurations that utilize `waverider` aerodynamics show great promise to reduce the vehicle weight. 5 refs.

  11. Vehicle Transient Air Conditioning Analysis: Model Development& System Optimization Investigations

    SciTech Connect

    Hendricks, T. J.

    2001-06-01

    The National Renewable Energy Laboratory (NREL) has developed a transient air conditioning (A/C) system model using SINDA/FLUINT analysis software. It captures all the relevant physics of transient A/C system performance, including two-phase flow effects in the evaporator and condenser, system mass effects, air side heat transfer on the condenser/evaporator, vehicle speed effects, temperature-dependent properties, and integration with a simplified cabin thermal model. It has demonstrated robust and powerful system design optimization capabilities. Single-variable and multiple variable design optimizations have been performed and are presented. Various system performance parameters can be optimized, including system COP, cabin cool-down time, and system heat load capacity. This work presents this new transient A/C system analysis and optimization tool and shows some high-level system design conclusions reached to date. The work focuses on R-134a A/C systems, but future efforts will modify the model to investigate the transient performance of alternative refrigerant systems such as carbon dioxide systems. NREL is integrating its transient air conditioning model into NRELs ADVISOR vehicle system analysis software, with the objective of simultaneously optimizing A/C system designs within the overall vehicle design optimization.

  12. Air liquefaction and enrichment system propulsion in reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Bond, W. H.; Yi, A. C.

    1994-07-01

    A concept is shown for a fully reusable, Earth-to-orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high-speed acceleration, both using liquid hydrogen for fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90% pure liquid oxygen as its oxidizer that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. This article shows an approach and the corresponding technology needs for using air liquefaction and enrichment system propulsion in a single-stage-to-orbit (SSTO) vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, in a direct substitution for aluminum or aluminum-lithium alloy, is critical to meet the structure weight objective for SSTO. Configurations that utilize 'waverider' aerodynamics show great promise to reduce the vehicle weight.

  13. Gas cushion control of OVJP print head position

    DOEpatents

    Forrest, Stephen R

    2014-10-07

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

  14. Comparative analysis of aluminum-air battery propulsion systems for passenger vehicles

    NASA Astrophysics Data System (ADS)

    Salisbury, J. D.; Behrin, E.; Kong, M. K.; Whisler, D. J.

    1980-02-01

    Three electric propulsion systems using an aluminum air battery were analyzed and compared to the internal combustion engine (ICE) vehicle. The engine and fuel systems of a representative five passenger highway vehicle were replaced conceptually by each of the three electric propulsion systems. The electrical vehicles were constrained by the computer simulation to be equivalent to the ICE vehicle in range and acceleration performance. The vehicle masses and aluminum consumption rates were then calculated for the electric vehicles and these data were used as figures of merit. The Al-air vehicles analyzed were (1) an Al-air battery only electric vehicle; (2) an Al-air battery combined with a nickel zinc secondary battery for power leveling and regenerative braking; and (3) an Al-air battery combined with a flywheel for power leveling and regenerative braking. All three electric systems compared favorably with the ICE vehicle.

  15. 78 FR 32223 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... AGENCY 40 CFR Parts 80, 85, 86, 600, 1036, 1037, 1065, and 1066 RIN 2060-A0 Control of Air Pollution From... (``EPA'') is announcing an extension of the public comment period for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule...

  16. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, J.M.; Luna, D.A.; Gwinn, K.W.

    1998-12-08

    An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening. 22 figs.

  17. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, J.M.; Luna, D.A.; Gwinn, K.W.

    1997-11-18

    An inflatable cushion assembly for use with an inflator comprises an inflatable cushion having an inner surface, outer surface, and at least one protrusion extending from one of the inner or outer surfaces. The inflatable cushion defines an opening between the inner surface and the outer surface for receiving the inflator. An attachment member contacts the one of the inner or outer surfaces adjacent the opening and includes a groove for receiving the protrusion, the attachment member securing the inflator within the opening. 22 figs.

  18. High specific energy and specific power aluminum/air battery for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Kindler, A.; Matthies, L.

    2014-06-01

    Micro air vehicles developed under the Army's Micro Autonomous Systems and Technology program generally need a specific energy of 300 - 550 watt-hrs/kg and 300 -550 watts/kg to operate for about 1 hour. At present, no commercial cell can fulfill this need. The best available commercial technology is the Lithium-ion battery or its derivative, the Li- Polymer cell. This chemistry generally provides around 15 minutes flying time. One alternative to the State-of-the Art is the Al/air cell, a primary battery that is actually half fuel cell. It has a high energy battery like aluminum anode, and fuel cell like air electrode that can extract oxygen out of the ambient air rather than carrying it. Both of these features tend to contribute to a high specific energy (watt-hrs/kg). High specific power (watts/kg) is supported by high concentration KOH electrolyte, a high quality commercial air electrode, and forced air convection from the vehicles rotors. The performance of this cell with these attributes is projected to be 500 watt-hrs/kg and 500 watts/kg based on simple model. It is expected to support a flying time of approximately 1 hour in any vehicle in which the usual limit is 15 minutes.

  19. Projection Moire Interferometry Measurements of Micro Air Vehicle Wings

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-01-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat s wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  20. CARS Temperature and Species Measurements For Air Vehicle Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Gord, James R.; Grisch, Frederic; Klimenko, Dmitry; Clauss, Walter

    2005-01-01

    The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engine. At Wright- Patterson Air Force Base in the United States, CARS has been used to simultaneously measure temperature and mole fractions of N2, O2 and CO2, in the exhaust stream of a liquid-fueled, gas-turbine combustor. At ONERA in France and the DLR in Germany researchers have used CARS to measure temperature and species concentrations in cryogenic LOX-H2 rocket combustion chambers. The primary aim of these measurements has been to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

  1. Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

    SciTech Connect

    Thomas, John F; Huff, Shean P; West, Brian H; Norman, Kevin M

    2012-01-01

    Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Four of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.

  2. GPS Auto-Navigation Design for Unmanned Air Vehicles

    NASA Technical Reports Server (NTRS)

    Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

    2003-01-01

    A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

  3. Low Earth Orbit Raider (LER) winged air launch vehicle concept

    NASA Technical Reports Server (NTRS)

    Feaux, Karl; Jordan, William; Killough, Graham; Miller, Robert; Plunk, Vonn

    1989-01-01

    The need to launch small payloads into low earth orbit has increased dramatically during the past several years. The Low Earth orbit Raider (LER) is an answer to this need. The LER is an air-launched, winged vehicle designed to carry a 1500 pound payload into a 250 nautical mile orbit. The LER is launched from the back of a 747-100B at 35,000 feet and a Mach number of 0.8. Three staged solid propellant motors offer safe ground and flight handling, reliable operation, and decreased fabrication cost. The wing provides lift for 747 separation and during the first stage burn. Also, aerodynamic controls are provided to simplify first stage maneuvers. The air-launch concept offers many advantages to the consumer compared to conventional methods. Launching at 35,000 feet lowers atmospheric drag and other loads on the vehicle considerably. Since the 747 is a mobile launch pad, flexibility in orbit selection and launch time is unparalleled. Even polar orbits are accessible with a decreased payload. Most importantly, the LER launch service can come to the customer, satellites and experiments need not be transported to ground based launch facilities. The LER is designed to offer increased consumer freedom at a lower cost over existing launch systems. Simplistic design emphasizing reliability at low cost allows for the light payloads of the LER.

  4. Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2006-01-01

    Large birds and glider pilots commonly use updrafts caused by convection in the lower atmosphere to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited air vehicles may also have the ability to exploit updrafts to improve performance. An updraft model was developed at NASA Dryden Flight Research Center (Edwards, California) to investigate the use of convective lift for uninhabited air vehicles in desert regions. Balloon and surface measurements obtained at the National Oceanic and Atmospheric Administration Surface Radiation station (Desert Rock, Nevada) enabled the model development. The data were used to create a statistical representation of the convective velocity scale, w*, and the convective mixing-layer thickness, zi. These parameters were then used to determine updraft size, vertical velocity profile, spacing, and maximum height. This paper gives a complete description of the updraft model and its derivation. Computer code for running the model is also given in conjunction with a check case for model verification.

  5. Zinc air battery development for electric vehicles. Final report

    SciTech Connect

    Putt, R.A.; Merry, G.W.

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  6. Measurement of air exchange rate of stationary vehicles and estimation of in-vehicle exposure.

    PubMed

    Park, J H; Spengler, J D; Yoon, D W; Dumyahn, T; Lee, K; Ozkaynak, H

    1998-01-01

    The air exchange rates or air changes per hour (ACH) were measured under 4 conditions in 3 stationary automobiles. The ACH ranged between 1.0 and 3.0 h-1 with windows closed and no mechanical ventilation, between 1.8 and 3.7 h-1 for windows closed with fan set on recirculation, between 13.3 and 26.1 h-1 for window open with no mechanical ventilation, and between 36.2 and 47.5 h-1 for window closed with the fan set on fresh air. ACHs for windows closed with no ventilation were higher for the older automobile than for the newer automobiles. With the windows closed and fan turned off, ACH was not influenced by wind speed (p > 0.05). When the window was open, ACH appeared to be greatly affected by wind speed (R2 = 0.86). These measurements are relevant to understanding exposures inside automobiles to sources such as dry-cleaned clothes, cigarettes and airbags. Therefore, to understand the in-vehicle exposure to these internal sources, perchloroethylene (PCE) emitted from dry-cleaned clothes and environmental tobacco smoke (ETS) inside a vehicle were modeled for simulated driving cycles. Airbag deployment was also modeled for estimating exposure level to alkaline particulate and carbon monoxide (CO). Average exposure to PCE inside a vehicle for 30 minutes period was high (approximately 780 micrograms/m3); however, this is only 6% of the two-week exposure that is influenced by the storage of dry cleaned clothing at home. On the other hand, the exposure levels of respirable suspended particulate (RSP) and formaldehyde due to ETS could reach 2.1 mg/m3 and 0.11 ppm, respectively, when a person smokes inside a driving car even with the window open. In modeling the in-vehicle concentrations following airbag deployment, the average CO level over 20 minutes would not appear to present problem (less than 28 ppm). The peak concentration of respirable particulate would have exceeded 140 mg/m3. Since most of the particle mass is composed of alkaline material, these high levels might be expected to cause harmful effects on susceptible people, such as asthmatics. In all modeled cases, ACH would significantly affect build-up and dilution of pollutants originating from internal sources. Frequent stopping in congested urban traffic can greatly increase short-term exposures. PMID:9470106

  7. Flexible Wing Base Micro Aerial Vehicles: Composite Materials for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Ettinger, Scott; Jenkins, David; Martinez, Luis

    2002-01-01

    This paper will discuss the development of the University of Florida's Micro Air Vehicle concept. A series of flexible wing based aircraft that possess highly desirable flight characteristics were developed. Since computational methods to accurately model flight at the low Reynolds numbers associated with this scale are still under development, our effort has relied heavily on trial and error. Hence a time efficient method was developed to rapidly produce prototype designs. The airframe and wings are fabricated using a unique process that incorporates carbon fiber composite construction. Prototypes can be fabricated in around five man-hours, allowing many design revisions to be tested in a short period of time. The resulting aircraft are far more durable, yet lighter, than their conventional counterparts. This process allows for thorough testing of each design in order to determine what changes were required on the next prototype. The use of carbon fiber allows for wing flexibility without sacrificing durability. The construction methods developed for this project were the enabling technology that allowed us to implement our designs. The resulting aircraft were the winning entries in the International Micro Air Vehicle Competition for the past two years. Details of the construction method are provided in this paper along with a background on our flexible wing concept.

  8. Flow sensitive actuators for micro-air vehicles

    NASA Astrophysics Data System (ADS)

    Kumar, V.; Hays, M.; Fernandez, E.; Oates, W.; Alvi, F. S.

    2011-10-01

    A macrofiber piezoelectric composite has been developed for boundary layer management of micro-air vehicles (MAVs). Specifically, a piezoelectric composite that is capable of self-sensing and controlling flow has been modeled, designed, fabricated, and tested in wind tunnel studies to quantify performance characteristics, such as the velocity field response to actuation, which is relevant for actively managing boundary layers (laminar and transition flow control). A nonlinear piezoelectric plate model was utilized to design the active structure for flow control. The dynamic properties of the piezoelectric composite actuator were also evaluated in situ during wind tunnel experiments to quantify sensing performance. Results based on velocity field measurements and unsteady pressure measurements show that these piezoelectric macrofiber composites can sense the state of flow above the surface and provide sufficient control authority to manipulate the flow conditions for transition from laminar to turbulent flow.

  9. Integration of an Autopilot for a Micro Air Vehicle

    NASA Technical Reports Server (NTRS)

    Platanitis, George; Shkarayev, Sergey

    2005-01-01

    Two autopilots providing autonomous flight capabilities are presented herein. The first is the Pico-Pilot, demonstrated for the 12-inch size class of micro air vehicles. The second is the MicroPilot MP2028(sup g), where its integration into a 36-inch Zagi airframe (tailless, elevons only configuration) is investigated and is the main focus of the report. Analytical methods, which include the use of the Advanced Aircraft Analysis software from DARCorp, were used to determine the stability and control derivatives, which were then validated through wind tunnel experiments. From the aerodynamic data, the linear, perturbed equations of motion from steady-state flight conditions may be cast in terms of these derivatives. Using these linear equations, transfer functions for the control and navigation systems were developed and feedback control laws based on Proportional, Integral, and Derivative (PID) control design were developed to control the aircraft. The PID gains may then be programmed into the autopilot software and uploaded to the microprocessor of the autopilot. The Pico-Pilot system was flight tested and shown to be successful in navigating a 12-inch MAV through a course defined by a number of waypoints with a high degree of accuracy, and in 20 mph winds. The system, though, showed problems with control authority in the roll and pitch motion of the aircraft: causing oscillations in these directions, but the aircraft maintained its heading while following the prescribed course. Flight tests were performed in remote control mode to evaluate handling, adjust trim, and test data logging for the Zagi with integrated MP2028(sup g). Ground testing was performed to test GPS acquisition, data logging, and control response in autonomous mode. Technical difficulties and integration limitations with the autopilot prevented fully autonomous flight from taking place, but the integration methodologies developed for this autopilot are, in general, applicable for unmanned air vehicles within the 36-inch size class or larger that use a PID control based autopilot.

  10. Air pollution and health risks due to vehicle traffic

    PubMed Central

    Zhang, Kai; Batterman, Stuart

    2014-01-01

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speedvolume relationship, the California Line Source Dispersion Model, an empirical NO2NOx relationship, estimated travel time changes during congestion, and concentrationresponse relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, U shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must consider travel time, the duration of rush-hour, congestion-specific emission estimates, and uncertainties. PMID:23500830

  11. H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT

    SciTech Connect

    Minichan, R.; Fogle, R.; Marzolf, A.

    2011-05-24

    The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.

  12. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.62 Section 3.62 Animals and Animal Products ANIMAL AND PLANT...

  13. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT...

  14. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.88 Section 3.88 Animals and Animal Products ANIMAL AND PLANT...

  15. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Optional equipment and air conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Compliance Provisions...

  16. Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range

    SciTech Connect

    Rugh, J.; Chaney, L.; Venson, T.; Ramroth, L.; Rose, M.

    2013-04-01

    The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles.

  17. 49 CFR 215.129 - Defective cushioning device.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Defective cushioning device. 215.129 Section 215... System 215.129 Defective cushioning device. A railroad may not place or continue in service a car if it has a cushioning device that is (a) Broken; (b) Inoperative; or (c) Missing a part unless...

  18. Air-Sea Interaction Measurements from the Controlled Towed Vehicle

    NASA Astrophysics Data System (ADS)

    Khelif, D.; Bluth, R. T.; Jonsson, H.; Barge, J.

    2014-12-01

    The Controlled Towed Vehicle (CTV) uses improved towed drone technology to actively maintain via a radar altimeter and controllable wing a user-set height that can be as low as the canonical reference height of 10 m above the sea surface. After take-off, the drone is released from the tow aircraft on a ~700-m stainless steel cable. We have instrumented the 0.23 m diameter and 2.13 m long drone with high fidelity instruments to measure the means and turbulent fluctuations of 3-D wind vector, temperature, humidity, pressure, CO2 and IR sea surface temperature. Data are recorded internally at 40 Hz and simultaneously transmitted to the tow aircraft via dedicated wireless Ethernet link. The CTV accommodates 40 kg of instrument payload and provides it with 250 W of continuous power through a ram air propeller-driven generator. Therefore its endurance is only limited by that of the tow aircraft.We will discuss the CTV development, the engineering challenges and solutions that have been successfully implemented to overcome them. We present results from recent flights as low as 9 m over the coastal ocean and comparisons of profiles and turbulent fluxes from the CTV and the tow aircraft. Manned aircraft operation at low-level boundary-layer flights is very limited. Dropsondes and UAS (Unmanned Aerial Systems) and UAS are alternates for measurements near the ocean surface. However, dropsondes have limited sensor capability and do not measure fluxes, and most present UAS vehicles do not have the payload and power capacity nor the low-flying ability in high winds over the oceans. The CTV therefore, fills a needed gap between the dropsondes, in situ aircraft, and UAS. The payload, capacity and power of the CTV makes it suitable for a variety of atmospheric research measurements. Other sensors to measure aerosol, chemistry, radiation, etc., could be readily accommodated in the CTV.

  19. Aerial networking communication solutions using Micro Air Vehicle (MAV)

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Shyam; de Graaf, Maurits; Hoekstra, Gerard; Corporaal, Henk; Wijtvliet, Mark; Cuadros Linde, Javier

    2014-10-01

    The application of a Micro Air Vehicle (MAV) for wireless networking is slowly gaining significance in the field of network robotics. Aerial transport of data requires efficient network protocols along with accurate positional adjustment of the MAV to minimize transaction times. In our proof of concept, we develop an Aerial networking protocol for data transfer using the technology of Disruption Tolerant Networks (DTN), a store-and-forward approach for environments that deals with disrupted connectivity. Our results show that close interaction between networking and flight behavior helps in efficient data exchange. Potential applications are in areas where network infrastructure is minimal or unavailable and distances may be large. For example, forwarding video recordings during search and rescue, agriculture, swarm communication, among several others. A practical implementation and validation, as described in this paper, presents the complex dynamics of wireless environments and poses new challenges that are not addressed in earlier work on this topic. Several tests are evaluated in a practical setup to display the networking MAV behavior during such an operation.

  20. Partial camera automation in an unmanned air vehicle.

    PubMed

    Korteling, J E; van der Borg, W

    1997-03-01

    The present study focused on an intelligent, semiautonomous, interface for a camera operator of a simulated unmanned air vehicle (UAV). This interface used system "knowledge" concerning UAV motion in order to assist a camera operator in tracking an object moving through the landscape below. The semiautomated system compensated for the translations of the UAV relative to the earth. This compensation was accompanied by the appropriate joystick movements ensuring tactile (haptic) feedback of these system interventions. The operator had to superimpose self-initiated joystick manipulations over these system-initiated joystick motions in order to track the motion of a target (a driving truck) relative to the terrain. Tracking data showed that subjects performed substantially better with the active system. Apparently, the subjects had no difficulty in maintaining control, i.e., "following" the active stick while superimposing self-initiated control movements over the system-interventions. Furthermore, tracking performance with an active interface was clearly superior relative to the passive system. The magnitude of this effect was equal to the effect of update-frequency (2-5 Hz) of the monitor image. The benefits of update frequency enhancement and semiautomated tracking were the greatest under difficult steering conditions. Mental workload scores indicated that, for the difficult tracking-dynamics condition, both semiautomation and update frequency increase resulted in less experienced mental effort. For the easier dynamics this effect was only seen for update frequency. PMID:11541093

  1. Transportation vehicle energy intensities. A joint DOT/NASA reference paper. [energy consumption of air and ground vehicles

    NASA Technical Reports Server (NTRS)

    Mascy, A. C.; Paullin, R. L.

    1974-01-01

    A compilation of data on the energy consumption of air and ground vehicles is presented. The ratio BTU/ASM, British Thermal Units/Available Seat Mile, is used to express vehicle energy intensiveness, and related to the energy consumed directly in producing seat-mile or ton-mile productivity. Data is presented on passenger and freight vehicles which are in current use or which are about to enter service, and advanced vehicles which may be operational in the 1980's and beyond. For the advanced vehicles, an estimate is given of the date of initial operational service, and the performance characteristics. Other key considerations in interpreting energy intensiveness for a given mode are discussed, such as: load factors, operations, overhead energy consumption, and energy investments in new structure and equipment.

  2. Preliminary performance estimates of an oblique, all-wing, remotely piloted vehicle for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Nelms, W. P., Jr.; Bailey, R. O.

    1974-01-01

    A computerized aircraft synthesis program has been used to assess the effects of various vehicle and mission parameters on the performance of an oblique, all-wing, remotely piloted vehicle (RPV) for the highly maneuverable, air-to-air combat role. The study mission consists of an outbound cruise, an acceleration phase, a series of subsonic and supersonic turns, and a return cruise. The results are presented in terms of both the required vehicle weight to accomplish this mission and the combat effectiveness as measured by turning and acceleration capability. This report describes the synthesis program, the mission, the vehicle, and results from sensitivity studies. An optimization process has been used to establish the nominal RPV configuration of the oblique, all-wing concept for the specified mission. In comparison to a previously studied conventional wing-body canard design for the same mission, this oblique, all-wing nominal vehicle is lighter in weight and has higher performance.

  3. A Randomized Clinical Trial on Preventing Pressure Ulcers with Wheelchair Seat Cushions

    PubMed Central

    Brienza, David; Kelsey, Sheryl; Karg, Patricia; Allegretti, Ana; Olson, Marian; Schmeler, Mark; Zanca, Jeanne; Geyer, Mary Jo; Kusturiss, Marybeth; Holm, Margo

    2010-01-01

    Objectives To determine the efficacy of skin protection wheelchair seat cushions in preventing pressure ulcers in the elderly, nursing home population Design Clinical trial with participants assigned at random to either a skin protection or segmented foam cushion. Two hundred thirty two participants were recruited between June 2004 and May 2008 and followed for 6 months or until pressure ulcer incidence. Setting Twelve nursing homes Participants Nursing home residents age ? 65, using wheelchairs ?6 hours/day, Braden score ? 18, and combined Braden activity and mobility score ? 5. Participants were recruited from a referred sample. Intervention All participants were provided a fitted wheelchair and randomized into skin protection (SPC) or segmented foam (SFC) cushion groups. The SPC group received an air, viscous fluid/foam, or gel/foam cushion. The SFC group received a 7.6 cm crosscut foam cushion. Measurements Pressure ulcer incidence over 6 months for wounds near the ischial tuberosities (IT ulcers) were measured. Secondary analysis was performed on combined IT and sacral/coccyx ulcers. Results One hundred eighty participants reached a study endpoint and 42 were lost to follow-up. Ten did not receive the intervention. There were 8/119 (6.7%) IT ulcers in the SFC group and 1/113 (0.9%) in the SPC group (p<0.04). In the group of combined IT and sacral/coccyx ulcers, there were 21/119 pressure ulcers (17.6%) in the SFC group and 12/113 (10.6%) in the SPC group (p=0.14). Conclusion Skin protection cushions used with fitted wheelchairs lower pressure ulcer incidence for elderly, nursing home residents and should be used to help prevent pressure ulcers. PMID:21070197

  4. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., rail, air, and marine). 3.62 Section 3.62 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... not have a supply of air sufficient for normal breathing for each live animal contained therein,...

  5. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., rail, air, and marine). 3.62 Section 3.62 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... not have a supply of air sufficient for normal breathing for each live animal contained therein,...

  6. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., rail, air, and marine). 3.62 Section 3.62 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... not have a supply of air sufficient for normal breathing for each live animal contained therein,...

  7. 9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., rail, air and marine). 3.114 Section 3.114 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air and marine). (a) The animal cargo space of primary conveyances used in... mammals must only be placed in animal cargo spaces that have a supply of air sufficient for each...

  8. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... cargo space that does not have a supply of air sufficient for normal breathing for each live...

  9. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., rail, air, and marine). 3.88 Section 3.88 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  10. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... cargo space that does not have a supply of air sufficient for normal breathing for each live...

  11. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... cargo space that does not have a supply of air sufficient for normal breathing for each live...

  12. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... cargo space that does not have a supply of air sufficient for normal breathing for each live...

  13. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., rail, air, and marine). 3.88 Section 3.88 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  14. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., rail, air, and marine). 3.88 Section 3.88 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  15. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., rail, air, and marine). 3.88 Section 3.88 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  16. Development of Micro Air Vehicle Technology With In-Flight Adaptive-Wing Structure

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R. (Technical Monitor); Shkarayev, Sergey; Null, William; Wagner, Matthew

    2004-01-01

    This is a final report on the research studies, "Development of Micro Air Vehicle Technology with In-Flight Adaptrive-Wing Structure". This project involved the development of variable-camber technology to achieve efficient design of micro air vehicles. Specifically, it focused on the following topics: 1) Low Reynolds number wind tunnel testing of cambered-plate wings. 2) Theoretical performance analysis of micro air vehicles. 3) Design of a variable-camber MAV actuated by micro servos. 4) Test flights of a variable-camber MAV.

  17. A Discussion of Aerodynamic Control Effectors (ACEs) for Unmanned Air Vehicles (UAVs)

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.

    2002-01-01

    A Reynolds number based, unmanned air vehicle classification structure has been developed which identifies four classes of unmanned air vehicle concepts. The four unmanned air vehicle (UAV) classes are; Micro UAV, Meso UAV, Macro UAV, and Mega UAV. In a similar fashion a labeling scheme for aerodynamic control effectors (ACE) was developed and eleven types of ACE concepts were identified. These eleven types of ACEs were laid out in a five (5) layer scheme. The final section of the paper correlated the various ACE concepts to the four UAV classes and ACE recommendations are offered for future design activities.

  18. Unmanned air vehicle (UAV) ultra-persitence research

    SciTech Connect

    Dron, S. B.

    2012-03-01

    Sandia National Laboratories and Northrop Grumman Corporation Integrated Systems, Unmanned Systems (NGIS UMS) collaborated to further ultra-persistence technologies for unmanned air vehicles (UAVs). The greatest shortfalls in UAV capabilities have been repeatedly identified as (1) insufficient flight persistence or 'hang time,' (2) marginal electrical power for running higher power avionics and payload systems, and (3) inadequate communications bandwidth and reach. NGIS UMS requested support from Sandia to develop an ultra-persistent propulsion and power system (UP3S) for potential incorporation into next generation UAV systems. The team members tried to determine which energy storage and power generation concepts could most effectively push UAV propulsion and electrical power capabilities to increase UAV sortie duration from days to months while increasing available electrical power at least two-fold. Primary research and development areas that were pursued included these goals: perform general system engineering and integration analyses; develop initial thermal and electrical power estimates; provide mass, volume, dimensional, and balance estimates; conduct preliminary safety assessments; assess logistics support requirements; perform, preliminary assessments of any security and safeguards; evaluate options for removal, replacement, and disposition of materials; generally advance the potential of the UP3S concept. The effort contrasted and compared eight heat sources technologies, three power conversion, two dual cycle propulsion system configurations, and a single electrical power generation scheme. Overall performance, specific power parameters, technical complexities, security, safety, and other operational features were successfully investigated. Large and medium sized UAV systems were envisioned and operational flight profiles were developed for each concept. Heat source creation and support challenges for domestic and expeditionary operations were considered. Fundamental cost driver analysis was also performed. System development plans were drafted in order to determine where the technological and programmatic critical paths lay. As a result of this effort, UAVs were to be able to provide far more surveillance time and intelligence information per mission while reducing the high cost of support activities. This technology was intended to create unmatched global capabilities to observe and preempt terrorist and weapon of mass destruction (WMD) activities. Various DOE laboratory and contractor personnel and facilities could have been used to perform detailed engineering, fabrication, assembly and test operations including follow-on operational support. Unfortunately, none of the results will be used in the near-term or mid-term future. NGIS UMS and SNL felt that the technical goals for the project were accomplished. NGIS UMS was quite pleased with the results of analysis and design although it was disappointing to all that the political realities would not allow use of the results. Technology and system designs evaluated under this CRADA had previously never been applied to unmanned air vehicles (UAVs). Based upon logistic support cost predictions, because the UAVs would not have had to refuel as often, forward basing support costs could have been reduced due to a decrease in the number and extent of support systems and personnel being required to operate UAVs in remote areas. Basic application of the advanced propulsion and power approach is well understood and industry now understands the technical, safety, and political issues surrounding implementation of these strategies. However, the overall economic impact was not investigated. The results will not be applied/implemented. No near-term benefit to industry or the taxpayer will be encountered as a result of these studies.

  19. Aerodynamics of unmanned combat air vehicles: Flow structure and control

    NASA Astrophysics Data System (ADS)

    Elkhoury, Michel

    At moderate to high angle-of-attack, an Unmanned Combat Air Vehicle (UCAV) exhibits complex flow structure due to vortex interaction/breakdown, and the onset of separation and stall. These features of the flow patterns have received little attention. The present investigation addresses the degree of interaction of vortices, the onset of vortex breakdown, and the occurrence of a separation as a function of both Reynolds number and angle-of-attack, via dye visualization and quantitative imaging. The Reynolds number dependence of the near-surface flow structure and topology on a representative UCAV planform is characterized using a technique of high-image-density particle image velocimetry (DPIV), as a complement to classical dye visualization. This technique provides a sequence of instantaneous states, as well as the corresponding time-averaged state. Patterns of streamline topology, including bifurcation lines, contours of streamwise and transverse velocity, surface-normal vorticity and Reynolds stress correlation, all immediately adjacent to the surface of the planform, provide quantitative interpretations. At low angle-of-attack, these quantitative patterns show significant alterations with Reynolds number, as represented by: large variations of patterns of vortex breakdown and vortex interaction visualized by dye; and substantial alterations of flow patterns in the crossflow plane, including reattachment phenomena, which are interpreted with patterns of velocity and streamwise vorticity. On the other hand, at moderate angle-of-attack, the near-surface quantitative patterns show much less sensitivity to Reynolds number, which is in accord with weak variations of the onset of vortex breakdown with changes in Reynolds number. Perturbations of the planform at a small amplitude and high frequency can substantially alter both the instantaneous and time-averaged flow structure immediately adjacent to its surface, relative to the case of a stationary planform. A ramp-like pitch up motion at different rates allows examination of the relaxation process of the flow structure adjacent to the surface after cessation of the motion.

  20. Fire resistant resilient foams. [for seat cushions

    NASA Technical Reports Server (NTRS)

    Gagliani, J.

    1976-01-01

    Primary program objectives were the formulation, screening, optimization and characterization of open-cell, fire resistant, low-smoke emitting, thermally stable, resilient polyimide foams suitable for seat cushions in commercial aircraft and spacecraft. Secondary program objectives were to obtain maximum improvement of the tension, elongation and tear characteristics of the foams, while maintaining the resiliency, thermal stability, low smoke emission and other desirable attributes of these materials.

  1. Space robot simulator vehicle

    NASA Technical Reports Server (NTRS)

    Cannon, R. H., Jr.; Alexander, H.

    1985-01-01

    A Space Robot Simulator Vehicle (SRSV) was constructed to model a free-flying robot capable of doing construction, manipulation and repair work in space. The SRSV is intended as a test bed for development of dynamic and static control methods for space robots. The vehicle is built around a two-foot-diameter air-cushion vehicle that carries batteries, power supplies, gas tanks, computer, reaction jets and radio equipment. It is fitted with one or two two-link manipulators, which may be of many possible designs, including flexible-link versions. Both the vehicle body and its first arm are nearly complete. Inverse dynamic control of the robot's manipulator has been successfully simulated using equations generated by the dynamic simulation package SDEXACT. In this mode, the position of the manipulator tip is controlled not by fixing the vehicle base through thruster operation, but by controlling the manipulator joint torques to achieve the desired tip motion, while allowing for the free motion of the vehicle base. One of the primary goals is to minimize use of the thrusters in favor of intelligent control of the manipulator. Ways to reduce the computational burden of control are described.

  2. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Emergency Generator Enclosure, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  3. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  4. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Clean Lubrication Oil Storage Tank & Enclosure, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  5. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Microwave Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  6. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Civil Engineering Storage Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  7. Venus Atmospheric Maneuverable Platform (VAMP) Air Vehicle Concept and Entry CONOPs

    NASA Astrophysics Data System (ADS)

    Sokol, D.; Lee, G.; Polidan, R.; Bolisay, L.; Barnes, N.

    2014-06-01

    This presentation discusses the continued development of the Northrop Grumman/LGARDE teams long-lived, maneuverable platform to explore the Venus upper atmosphere. It focuses on the air vehicle design and entry CONOPs and their interdependencies.

  8. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  9. Fugitive particulate air emissions from off-road vehicle maneuvers at military training lands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Military training lands used for off-road vehicle maneuvers may be subject to severe soil loss and air quality degradation as a result of severe wind erosion. The objective of this study was to measure suspended particulate matter resulting from various different vehicle training scenarios. Soil s...

  10. Assessing the Link between Environmental Concerns and Consumers' Decisions to Use Clean-Air Vehicles

    ERIC Educational Resources Information Center

    Plax, Timothy G.; Kearney, Patricia; Ross, Ted J.; Jolly, J. Christopher

    2008-01-01

    A consulting contract with the California Air Resources Board led to a project examining how California drivers' and fleet managers' perceptions, attitudes, and consumer behavior regarding Clean Vehicle Technologies influenced their own energy choices when it came to purchasing vehicles. The consultants examined archival research, conducted focus…

  11. Assessing the Link between Environmental Concerns and Consumers' Decisions to Use Clean-Air Vehicles

    ERIC Educational Resources Information Center

    Plax, Timothy G.; Kearney, Patricia; Ross, Ted J.; Jolly, J. Christopher

    2008-01-01

    A consulting contract with the California Air Resources Board led to a project examining how California drivers' and fleet managers' perceptions, attitudes, and consumer behavior regarding Clean Vehicle Technologies influenced their own energy choices when it came to purchasing vehicles. The consultants examined archival research, conducted focus

  12. Measuring concentrations of selected air pollutants inside California vehicles. Final report

    SciTech Connect

    Rodes, C.; Sheldon, L.; Whitaker, D.; Clayton, A.; Fitzgerald, K.

    1999-01-01

    This project measured 2-hour integrated concentrations of PM10, PM2.5, metals and a number of organic chemicals including benzene and MTBE inside vehicles on California roadways. Using continuous samplers, particle counts, black carbon, and CO were also measured. In addition to measuring in-vehicle levels, the investigators measured pollutant levels just outside the vehicle, at roadside stations, and ambient air monitoring stations. Different driving scenarios were designed to assess the effects of a number of factors on in-vehicle pollutant levels. These factors included roadway type, carpool lanes, traffic conditions, geographical locations, vehicle type, and vehicle ventilation conditions. The statewide average in-vehicle concentrations of benzene, MTBE, and formaldehyde ranged from 3--22 {micro}g/m{sup 3}, 3--90 {micro}g/m{sup 3}, and 0---22 {micro}g/m{sup 3}, respectively. The ranges of mean PM10 and PM2.5 in-vehicle levels in Sacramento were 20--40 {micro}g/m{sup 3} and 6--22 {micro}g/m{sup 3}, respectively. In general, pollutant levels inside or just outside the vehicles were higher than those measured at the roadside stations or the ambient air stations. In-vehicle pollutant levels were consistently higher in Los Angeles than Sacramento. Pollutant levels measured inside vehicles traveling in a carpool lane were much lower than those in the right-hand, slower lanes. Under the study conditions, factors such as vehicle type and ventilation and little effect on in-vehicle pollutant levels. Other factors, such as roadway type, freeway congestion level, and time-of-day had some influence on in-vehicle pollution levels.

  13. The promise of air cargo: System aspects and vehicle design

    NASA Technical Reports Server (NTRS)

    Whitehead, A. H., Jr.

    1976-01-01

    The current operation of the air cargo system is reviewed. An assessment of the future of air cargo is provided by: (1) analyzing statistics and trends, (2) by noting system problems and inefficiencies, (3) by analyzing characteristics of 'air eligible' commodities, and (4) by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. The following topics are discussed: (1) air cargo demand forecasts; (2) economics of air cargo transport; (3) the integrated air cargo system; (4) evolution of airfreighter design; and (5) the span distributed load concept.

  14. Vehicle performance optimization utilizing the air turbo-ramjet propulsion system: Methodology development and applications

    NASA Astrophysics Data System (ADS)

    Christensen, Kirk Le

    The ATR (Air TurboRocket) is an air breathing propulsion system in which the turbocompressor turbine is powered by a hot drive gas which is generated independently of the air flow through the compressor. The ATR has a lower specific impulse (Isp) and higher thrust compared to a similar size turbojet but a lower thrust and higher Isp compared to similar size solid rocket motor (SRM). This work defines the benefits of ATR propulsion for tactical vehicles. ATR simulation codes were developed to support analysis of hypothetical ATR powered vehicles. Both turbojet powered and SRM powered vehicles were also evaluated against range and time of flight as the major evaluation criteria. This analysis required the use of an existing turbojet code, a solid rocket motor (SRM) model, an aerodynamics predictor code (DATCOM) and a two dimensional, flat earth trajectory analysis code (ZTRAJ). Two weight class vehicles (800 and 3500 lbsbm) launched at Mach 0.9 and 10000 feet altitude were evaluated as well as a low Mach (0.1) launch of the 800 lbsbm class vehicle. These vehicles, with the three propulsion system options, required nine vehicle/trajectory analyses. The results of these analyses show that only the ATR powered vehicle is able to simultaneously meet minimum range and maximum flight time requirements. The SRM powered vehicle (because of its low Isp) only achieves about 50% of the range of the ATR powered vehicle. The turbojet powered vehicle (because of its low thrust) required more than 30% of the flight time required by the ATR powered vehicle for the same range.

  15. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... 40 Protection of Environment 19 2010-07-01 2010-07-01 false Optional equipment and...

  16. 9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., rail, air and marine). 3.114 Section 3.114 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air and marine). (a) The animal cargo space of primary conveyances used in... animal cargo space must be constructed and maintained in a manner that will prevent the ingress of...

  17. 9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., rail, air and marine). 3.114 Section 3.114 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air and marine). (a) The animal cargo space of primary conveyances used in... animal cargo space must be constructed and maintained in a manner that will prevent the ingress of...

  18. Micro air vehicle motion tracking and aerodynamic modeling

    NASA Astrophysics Data System (ADS)

    Uhlig, Daniel V.

    Aerodynamic performance of small-scale fixed-wing flight is not well understood, and flight data are needed to gain a better understanding of the aerodynamics of micro air vehicles (MAVs) flying at Reynolds numbers between 10,000 and 30,000. Experimental studies have shown the aerodynamic effects of low Reynolds number flow on wings and airfoils, but the amount of work that has been conducted is not extensive and mostly limited to tests in wind and water tunnels. In addition to wind and water tunnel testing, flight characteristics of aircraft can be gathered through flight testing. The small size and low weight of MAVs prevent the use of conventional on-board instrumentation systems, but motion tracking systems that use off-board triangulation can capture flight trajectories (position and attitude) of MAVs with minimal onboard instrumentation. Because captured motion trajectories include minute noise that depends on the aircraft size, the trajectory results were verified in this work using repeatability tests. From the captured glide trajectories, the aerodynamic characteristics of five unpowered aircraft were determined. Test results for the five MAVs showed the forces and moments acting on the aircraft throughout the test flights. In addition, the airspeed, angle of attack, and sideslip angle were also determined from the trajectories. Results for low angles of attack (less than approximately 20 deg) showed the lift, drag, and moment coefficients during nominal gliding flight. For the lift curve, the results showed a linear curve until stall that was generally less than finite wing predictions. The drag curve was well described by a polar. The moment coefficients during the gliding flights were used to determine longitudinal and lateral stability derivatives. The neutral point, weather-vane stability and the dihedral effect showed some variation with different trim speeds (different angles of attack). In the gliding flights, the aerodynamic characteristics exhibited quasi-steady effects caused by small variations in the angle of attack. The quasi-steady effects, or small unsteady effects, caused variations in the aerodynamic characteristics (particularly incrementing the lift curve), and the magnitude of the influence depended on the angle-of-attack rate. In addition to nominal gliding flight, MAVs in general are capable of flying over a wide flight envelope including agile maneuvers such as perching, hovering, deep stall and maneuvering in confined spaces. From the captured motion trajectories, the aerodynamic characteristics during the numerous unsteady flights were gathered without the complexity required for unsteady wind tunnel tests. Experimental results for the MAVs show large flight envelopes that included high angles of attack (on the order of 90 deg) and high angular rates, and the aerodynamic coefficients had dynamic stall hysteresis loops and large values. From the large number of unsteady high angle-of-attack flights, an aerodynamic modeling method was developed and refined for unsteady MAV flight at high angles of attack. The method was based on a separation parameter that depended on the time history of the angle of attack and angle-of-attack rate. The separation parameter accounted for the time lag inherit in the longitudinal characteristics during dynamic maneuvers. The method was applied to three MAVs and showed general agreement with unsteady experimental results and with nominal gliding flight results. The flight tests with the MAVs indicate that modern motion tracking systems are capable of capturing the flight trajectories, and the captured trajectories can be used to determine the aerodynamic characteristics. From the captured trajectories, low Reynolds number MAV flight is explored in both nominal gliding flight and unsteady high angle-of-attack flight. Building on the experimental results, a modeling method for the longitudinal characteristics is developed that is applicable to the full flight envelope.

  19. Segmented tubular cushion springs and spring assembly

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1988-01-01

    A spring (10) includes a tube (12) having an elliptical cross section, with the greater axial dimension (22) extending laterally and the lesser axial dimension (24) extending vertically. A plurality of cuts (20) in the form of slots passing through most of a wall of the tube (12) extend perpendicularly to a longitudinal axis (16) extending along the tube (12). An uncut portion (26) of the tube wall extends along the tube (12) for bonding or fastening the tube to a suitable base, such as a bottom (28) of a seat cushion (30).

  20. Segmented tubular cushion springs and spring assembly

    NASA Technical Reports Server (NTRS)

    Haslim, L. A. (Inventor)

    1985-01-01

    A spring which includes a tube with an elliptical cross section, with the greater axial dimension extending laterally and the lesser axial dimension extending vertically is disclosed. A plurality of cuts in the form of slots passing through most of a wall of the tube extend perpendiculary to a longitudinal axis extending along the tube. An uncut portion of the tube wall extends along the tube for bonding or fastening the tube to a suitable base, such as a bottom of a seat cushion.

  1. Fire blocking systems for aircraft seat cushions

    NASA Technical Reports Server (NTRS)

    Parker, J. A.; Kourtides, D. A. (Inventor)

    1984-01-01

    A configuration and method for reducing the flammability of bodies of organic materials that thermally decompose to give flammable gases comprises covering the body with a flexible matrix that catalytically cracks the flammable gases to less flammable species. Optionally, the matrix is covered with a gas impermeable outer layer. In a preferred embodiment, the invention takes the form of an aircraft seat in which the body is a poly(urethane) seat cushion, the matrix is an aramid fabric or felt and the outer layer is an aluminum film.

  2. Consequential life cycle air emissions externalities for plug-in electric vehicles in the PJM interconnection

    NASA Astrophysics Data System (ADS)

    Weis, Allison; Jaramillo, Paulina; Michalek, Jeremy

    2016-02-01

    We perform a consequential life cycle analysis of plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), and conventional gasoline vehicles in the PJM interconnection using a detailed, normative optimization model of the PJM electricity grid that captures the change in power plant operations and related emissions due to vehicle charging. We estimate and monetize the resulting human health and environmental damages from life cycle air emissions for each vehicle technology. We model PJM using the most recent data available (2010) as well as projections of the PJM grid in 2018 and a hypothetical scenario with increased wind penetration. We assess a range of sensitivity cases to verify the robustness of our results. We find that PEVs have higher life cycle air emissions damages than gasoline HEVs in the recent grid scenario, which has a high percentage of coal generation on the margin. In particular, battery electric vehicles with large battery capacity can produce two to three times as much air emissions damage as gasoline HEVs, depending on charge timing. In our future 2018 grid scenarios that account for predicted coal plant retirements, PEVs would produce air emissions damages comparable to or slightly lower than HEVs.

  3. Proposal for a Vehicle Level Test Procedure to Measure Air Conditioning Fuel Use

    SciTech Connect

    Rugh, J. P.

    2010-04-01

    The air-conditioning (A/C) compressor load significantly impacts the fuel economy of conventional vehicles and the fuel use/range of plug-in hybrid electric vehicles (PHEV). A National Renewable Energy Laboratory (NREL) vehicle performance analysis shows the operation of the air conditioner reduces the charge depletion range of a 40-mile range PHEV from 18% to 30% in a worst case hot environment. Designing for air conditioning electrical loads impacts PHEV and electric vehicle (EV) energy storage system size and cost. While automobile manufacturers have climate control procedures to assess A/C performance, and the U.S. EPA has the SCO3 drive cycle to measure indirect A/C emissions, there is no automotive industry consensus on a vehicle level A/C fuel use test procedure. With increasing attention on A/C fuel use due to increased regulatory activities and the development of PHEVs and EVs, a test procedure is needed to accurately assess the impact of climate control loads. A vehicle thermal soak period is recommended, with solar lamps that meet the SCO3 requirements or an alternative heating method such as portable electric heaters. After soaking, the vehicle is operated over repeated drive cycles or at a constant speed until steady-state cabin air temperature is attained. With this method, the cooldown and steady-state A/C fuel use are measured. This method can be run at either different ambient temperatures to provide data for the GREEN-MAC-LCCP model temperature bins or at a single representative ambient temperature. Vehicles with automatic climate systems are allowed to control as designed, while vehicles with manual climate systems are adjusted to approximate expected climate control settings. An A/C off test is also run for all drive profiles. This procedure measures approximate real-world A/C fuel use and assess the impact of thermal load reduction strategies.

  4. Air actuated clutch for four wheel drive vehicles

    SciTech Connect

    Clohessy, K.E.

    1986-12-09

    A control system is described for selectively engaging and disengaging a vehicle wheel and a vehicle drive mechanism comprising; a spindle having inside and outside rotative support surfaces, the spindle adapted to be mounted to a vehicle frame, an axle portion rotatably supported on the inside support surface, and drive means for selectively and rotatively driving the axle portion relative to the spindle; a wheel hub assembly adapted to carry a vehicle wheel, the hub assembly rotatively supported on the outside support surface of the spindle; a sealed expansion chamber defined in part by the spindle, the axle portion, the hub assembly and a movable wall carried by the hub assembly, venting means venting the outer side of the movable wall to atmospheric pressure, the clutch ring engaged by the movable wall for movement of the clutch ring with movement of the movable wall as induced by a pressure difference generated within the chamber, and pressurizing means for selectively pressurizing and depressurizing the expansion chamber to thereby selectively shift the clutch ring between the positions of interlocking the axle portion and hub assembly and unlocking the axle portion and hub assembly.

  5. Prospects for future hypersonic air-breathing vehicles

    NASA Technical Reports Server (NTRS)

    Beach, H. L., Jr.; Blankson, Isaiah M.

    1991-01-01

    An overview of the technical progress achieved in key areas of hypersonic airbreathing vehicle development is presented. The context for hypersonic applications is discussed with emphasis placed on technology issues and requirements, particularly for propulsion and technology integration. Attention is given to CFD technology which allows the consideration of configurations and extrapolations to flight conditions that cannot be simulated on the ground.

  6. Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

    2003-01-01

    The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic air- breathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjetkcramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demon- strate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and develop ment cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

  7. Modeling and analysis of an articulated winged micro air vehicle for gust mitigation

    NASA Astrophysics Data System (ADS)

    Oduyela, Adetunji Y.

    Articulated micro air vehicles are a class of micro air vehicles comprised of a main center body attached to outer wings on both sides. As in the case of a single rigid micro air vehicle, the center body and the attached bodies in the articulated case are all responsible for the generation of aerodynamic forces and moments during flight resulting in a multibody system. While many approaches have been taken in the literature to model the system of equations resulting from such a complicated multibody system, this dissertation presents an approach based on a Newton-Euler multibody dynamics formulation where the multiple bodies are attached together with suitable joints. The number and type of joints determines the level of articulation and total degree of freedom for the entire system. Unlike most articulated air vehicle model formulations available in the literature, the final model formulation presented in this work provides joint force and moment data acting on the articulated MAV during flight. This feature allows such information to be available during the vehicle design and development stage where appropriate spring and dampers for the system are selected based on mission requirements. Experimental validation of the proposed mathematical model using experimental flight test data obtained from UAHuntsville's Autonomous Tracking and Optical Measurements laboratory allowed the comparison of the flight test results and model simulations. Analytical investigation of the gust alleviation properties of the articulated 8 degree-of-freedom micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes and shows that the passive articulation in micro air vehicles increases their robustness to gusts when suitable joint parameters are selected.

  8. Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits.

    PubMed

    Michalek, Jeremy J; Chester, Mikhail; Jaramillo, Paulina; Samaras, Constantine; Shiau, Ching-Shin Norman; Lave, Lester B

    2011-10-01

    We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO(2) emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent. PMID:21949359

  9. Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits

    PubMed Central

    Michalek, Jeremy J.; Chester, Mikhail; Jaramillo, Paulina; Samaras, Constantine; Shiau, Ching-Shin Norman; Lave, Lester B.

    2011-01-01

    We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO2 emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent. PMID:21949359

  10. Thermal Performance of Aircraft Polyurethane Seat Cushions

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1982-01-01

    Aircraft seat materials were evaluated in terms of their thermal performance. The materials were evaluated using (a) thermogravimetric analysis, (b) differential scanning calorimetry, (c) a modified NBS smoke chamber to determine the rate of mass loss and (d) the NASA T-3 apparatus to determine the thermal efficiency. In this paper, the modified NBS smoke chamber will be described in detail since it provided the most conclusive results. The NBS smoke chamber was modified to measure the weight loss of material when exposed to a radiant heat source over the range of 2.5 to 7.5 W/sq cm. This chamber has been utilized to evaluate the thermal performance of various heat blocking layers utilized to protect the polyurethane cushioning foam used in aircraft seats. Various kinds of heat blocking layers were evaluated by monitoring the weight loss of miniature seat cushions when exposed to the radiant heat. The effectiveness of aluminized heat blocking systems was demonstrated when compared to conventional heat blocking layers such as neoprene. All heat blocking systems showed good fire protection capabilities when compared to the state-of-the-art, i.e., wool-nylon over polyurethane foam.

  11. Combatting urban air pollution through Natural Gas Vehicle (NGV) analysis, testing, and demonstration

    SciTech Connect

    1995-03-01

    Deteriorating urban air quality ranks as a top concern worldwide, since air pollution adversely affects both public health and the environment. The outlook for improving air quality in the world`s megacities need not be bleak, however, The use of natural gas as a transportation fuel can measurably reduce urban pollution levels, mitigating chronic threats to health and the environment. Besides being clean burning, natural gas vehicles (NGVs) are economical to operate and maintain. The current cost of natural gas is lower than that of gasoline. Natural gas also reduces the vehicle`s engine wear and noise level, extends engine life, and decreases engine maintenance. Today, about 700,000 NGVs operate worldwide, the majority of them converted from gasoline or diesel fuel. This article discusses the economic, regulatory and technological issues of concern to the NGV industry.

  12. An Expert Fault Diagnosis System for Vehicle Air Conditioning Product Development

    NASA Astrophysics Data System (ADS)

    Tan, C. F.; Tee, B. T.; Khalil, S. N.; Chen, W.; Rauterberg, G. W. M.

    2015-09-01

    The paper describes the development of the vehicle air-conditioning fault diagnosis system in automotive industries with expert system shell. The main aim of the research is to diagnose the problem of new vehicle air-conditioning system development process and select the most suitable solution to the problems. In the vehicle air-conditioning manufacturing industry, process can be very costly where an expert and experience personnel needed in certain circumstances. The expert of in the industry will retire or resign from time to time. When the expert is absent, their experience and knowledge is difficult to retrieve or lost forever. Expert system is a convenient method to replace expert. By replacing the expert with expert system, the accuracy of the processes will be increased compared to the conventional way. Therefore, the quality of product services that are produced will be finer and better. The inputs for the fault diagnosis are based on design data and experience of the engineer.

  13. Comparisons of rocket and air-breathing vehicle concepts for earth-to-orbit transportarion

    NASA Astrophysics Data System (ADS)

    Dorrington, G. E.

    1990-07-01

    To illustrate that there is ample room for improvement in earth-to-orbit reliability, transportation cost and environmental cleanliness, some future European launch vehicle concepts are presented. Varying assumptions of technology level and operational strategy offer a wide range of system/subsystem options for consideration. Specific examples cited include: the advanced reusable single-stage VTOL all-rocket vehicles, the all-liquid hydrogen-oxygen variants of Ariane 5, and the advanced one-and-a-half-stage horizontal take-off air-breathing vehicles.

  14. Experimental investigation of a quad-rotor biplane micro air vehicle

    NASA Astrophysics Data System (ADS)

    Bogdanowicz, Christopher Michael

    Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air vehicle which seamlessly combines both flight capabilities: hover and high-speed forward flight. It is the quad-rotor biplane, which weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the vehicle system was investigated in conditions representative of flight through a series of wind tunnel experiments. These studies provided an understanding of propeller-wing interaction effects and system trim analysis. This showed that the maximum speed of 11 m/s and a cruise speed of 4 m/s were achievable and that the cruise power is approximately one-third of the hover power. Free flight testing of the vehicle successfully highlighted its ability to achieve equilibrium transition flight. Key design parameters were experimentally investigated to understand their effect on overall performance. It was found that a trade-off between efficiency and compactness affects the final choice of the design. Design improvements have allowed for decreases in vehicle weight and ground footprint, while increasing structural soundness. Numerous vehicle designs, models, and flight tests have proven system scalability as well as versatility, including an upscaled model to be utilized in an extensive commercial package delivery system. Overall, the quad-rotor biplane is proven to be an efficient and effective multi-role vehicle.

  15. Configuration Studies of Personal Air Vehicles. Personal Air Vehicle and Flying Jeep Concepts: A Commentary on Promising Approaches or What Goes Around Comes Around (About Every Twenty Years)

    NASA Technical Reports Server (NTRS)

    Hall, David W.

    2001-01-01

    The NASA/Langley Personal Air Vehicle (PAV) Exploration (PAVE) and the DARPA (Defense Advanced Research Projects Agency) Dual Air/Road Transportation System (DARTS) projects were established to investigate the feasibility of creating vehicles which could replace, or at the very least augment, personal ground and air transportation schemes. This overall goal implies integrating several technology areas with practical everyday transportation requirements to design a class of vehicles which will achieve the following goals: (1) Vertical, Extremely Short, or Short Takeoff and Landing (VTOL, ESTOL, STOL) capability; (2) Operation at block speeds markedly faster than current combinations of land and air transportation, particularly in critical market areas; (3) Unit cost comparable to current luxury cars and small general aviation aircraft; (4) Excellent reliability; (5) Excellent safety; (6) Ability to integrate with existing land and air transportation systems. The conclusions of these configuration studies are summarized as follows: (1) Creation of the five assigned configurations prompted added explorations, some of which were dead-ends; (2) Some components could be common to all configurations such as avionics and dual-mode suspension schemes; (3) Single-Mode PAVs can be created by removing dual-mode-specific items; (4) Aviation history provided some intriguing starting points, as in what goes around comes around; (5) CTOL (Conventional Take-off and Landing) and STOL dual-mode PAVs look feasible with single-mode PAVs being simplifications of the dual-mode approach; (6) VTOL PAVs will require development; (7) More exotic collapsing mechanisms mechanisms need development; (8) As a teaching tool, PAVs are not yet a well-enough bounded design problem.

  16. Propulsion integration of hypersonic air-breathing vehicles utilizing a top-down design methodology

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Brad Kenneth

    In recent years, a focus of aerospace engineering design has been the development of advanced design methodologies and frameworks to account for increasingly complex and integrated vehicles. Techniques such as parametric modeling, global vehicle analyses, and interdisciplinary data sharing have been employed in an attempt to improve the design process. The purpose of this study is to introduce a new approach to integrated vehicle design known as the top-down design methodology. In the top-down design methodology, the main idea is to relate design changes on the vehicle system and sub-system level to a set of over-arching performance and customer requirements. Rather than focusing on the performance of an individual system, the system is analyzed in terms of the net effect it has on the overall vehicle and other vehicle systems. This detailed level of analysis can only be accomplished through the use of high fidelity computational tools such as Computational Fluid Dynamics (CFD) or Finite Element Analysis (FEA). The utility of the top-down design methodology is investigated through its application to the conceptual and preliminary design of a long-range hypersonic air-breathing vehicle for a hypothetical next generation hypersonic vehicle (NHRV) program. System-level design is demonstrated through the development of the nozzle section of the propulsion system. From this demonstration of the methodology, conclusions are made about the benefits, drawbacks, and cost of using the methodology.

  17. Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

    2002-01-01

    The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic airbreathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjet/scramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demonstrate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and development cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

  18. Improving the aluminum-air battery system for use in electrical vehicles

    NASA Astrophysics Data System (ADS)

    Yang, Shaohua

    The objectives of this study include improvement of the efficiency of the aluminum/air battery system and demonstration of its ability for vehicle applications. The aluminum/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum/air battery vehicle life cycle analysis was conducted and compared to that of lead/acid and nickel-metal hydride vehicles. Only the aluminum/air vehicles can be projected to have a travel range comparable to that of internal combustion engine vehicles (ICE). From this analysis, an aluminum/air vehicle is a promising candidate compared to ICE vehicles in terms of travel range, purchase price, fuel cost, and life cycle cost. We have chosen two grades of Al alloys (Al alloy 1350, 99.5% and Al alloy 1199, 99.99%) in our study. Only Al 1199 was studied extensively using Na 2SnO3 as an electrolyte additive. We then varied concentration and temperature, and determined the effects on the parasitic (corrosion) current density and open circuit potential. We also determined cell performance and selectivity curves. To optimize the performance of the cell based on our experiments, the recommended operating conditions are: 3--4 N NaOH, about 55C, and a current density of 150--300 mA/cm2. We have modeled the cell performance using the equations we developed. The model prediction of cell performance shows good agreement with experimental data. For better cell performance, our model studies suggest use of higher electrolyte flow rate, smaller cell gap, higher conductivity and lower parasitic current density. We have analyzed the secondary current density distributions in a two plane, parallel Al/air cell and a wedge-type Al/air cell. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the local current density increases, but the increase is not as significant as the increase in the current density away from the entrance. By extending the cathode below the anode, the high local current density can be reduced.

  19. Evaluating the Vibration Isolation of Soft Seat Cushions Using AN Active Anthropodynamic Dummy

    NASA Astrophysics Data System (ADS)

    LEWIS, C. H.; GRIFFIN, M. J.

    2002-05-01

    Seat test standards require human subjects to be used for measuring the vibration isolation of vehicle seats. Anthropodynamic dummies, based on passive mass-spring- damper systems, have been developed for testing seats but their performance has been limited at low excitation magnitudes by non-linear phenomena, such as friction in the mechanical components that provide damping. The use of an electrodynamic actuator to generate damping forces, controlled by feedback from acceleration and force transducers, may help to overcome these limitations and provide additional benefits. The transmissibilities of five foam cushions have been measured using an actively controlled anthropodynamic dummy, in which damping and spring forces were supplied by an electrodynamic actuator. The dummy could be set up to approximate alternative single-degree-of-freedom and two-degree-of-freedom apparent mass models of the seated human body by varying motion feedback parameters. Cushion transmissibilities were also measured with nine human subjects, having an average seated weight similar to the dummy. At frequencies greater than 4 Hz, mean cushion transmissibilities measured with subjects were in closer agreement with the transmissibilities obtained with a two degree-of-freedom dummy than with a single degree-of-freedom dummy. However, at frequencies between 2 and 4 Hz, cushion transmissibilities obtained with the two-degree-of-freedom dummy showed consistently larger differences from mean transmissibilities with subjects than single-degree-of-freedom dummies, indicating a need for further development of human apparent mass models to account for the effects of magnitude and spectral content of the input motion. Vertical vibration isolation efficiencies (SEAT values) of the five foams were measured with four input motions, including three motions measured in a car. The SEAT values obtained using the active dummy were highly correlated with the median SEAT values obtained with the nine human subjects, with the two-degree-of-freedom apparent mass dummy giving the highest agreement.

  20. Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2005-01-01

    A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cross-country speed. This report presents a quantitative analysis of a small electric-powered uninhabited air vehicle using updrafts to extend its endurance over a target location. A three-degree-of-freedom simulation of the uninhabited air vehicle was used to determine the yearly effect of updrafts on performance. Surface radiation and rawinsonde balloon measurements taken at Desert Rock, Nevada, were used to determine updraft size, strength, spacing, shape, and maximum height for the simulation. A fixed-width spiral path was used to search for updrafts at the same time as maintaining line-of-sight to the surface target position. Power was used only when the aircraft was flying at the lower-altitude limit in search of updrafts. Results show that an uninhabited air vehicle with a nominal endurance of 2 hours can fly a maximum of 14 hours using updrafts during the summer and a maximum of 8 hours during the winter. The performance benefit and the chance of finding updrafts both depend on what time of day the uninhabited air vehicle is launched. Good endurance and probability of finding updrafts during the year was obtained when the uninhabited air vehicle was launched 30 percent into the daylight hours after sunrise each day. Yearly average endurance was found to be 8.6 hours with these launch times.

  1. Design and analysis of aluminum/air battery system for electric vehicles

    NASA Astrophysics Data System (ADS)

    Yang, Shaohua; Knickle, Harold

    Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

  2. Development of Micro Air Reconnaissance Vehicle as a Test Bed for Advanced Sensors and Electronics

    NASA Technical Reports Server (NTRS)

    Shams, Qamar A.; Vranas, Thomas L.; Fox, Robert L.; Kuhn, Theodore R.; Ingham, John; Logan, Michael J.; Barnes, Kevin N.; Guenther, Benjamin F.

    2002-01-01

    This paper describes the development of a Micro/Mini Air Reconnaissance Vehicle for advanced sensors and electronics at NASA Langley Research Center over the last year. This vehicle is expected to have a total weight of less than four pounds, a design velocity of 40 mph, an endurance of 15-20 minutes, and a maximum range of 5km. The vehicle has wings that are simple to detach yet retain the correct alignment. The upper fuselage surface has a quick release hatch used to access the interior and also to mount the varying propulsion systems. The sensor suite developed for this vehicle consists of a Pitot-static measurement system for determining air speed, an absolute pressure measurement for determining altitude, magnetic direction measurement, and three orthogonal gyros to determine body angular rates. Swarming GPS-guidance and in-flight maneuvering is discussed, as well as design and installation of some other advance sensors like MEMS microphones, infrared cameras, GPS, humidity sensors, and an ultrasonic sonar sensor. Also low cost, small size, high performance control and navigation system for the Micro Air Vehicle is discussed. At the end, laboratory characterization of different sensors, motors, propellers, and batteries will be discussed.

  3. Seacoaster advanced marine vehicle. Final report

    SciTech Connect

    Burg, D.

    1998-08-18

    The Seacoaster combines the high efficiencies of Surface Effect Ships (SES) with simple catamaran hull construction. It has blower pressurized air cushions that support some 80-90 percent of displacement and hence the high efficiencies. However, unlike the SES, there are no expensive and high maintenance flexible seals. Each catamaran sidehull has a simple recess molded or built into its underside. Powered blowers direct pressurized air into such recesses and thereby create lifting air cushions. There are no flexible seals of any kind and there is no air cushion between the sidehulls. Extensive towed model tests were conducted that showed the viability of the invention.

  4. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better aerodynamic data. The second part of research involves preliminary work required to generate new aerodynamic data for the nonlinear model. First, a computational mesh is created over a 2-D wing section of the MAV model. A finite volume based computational flow solver is used to test different flapping trajectories of the wing section. Finally, a parametric study of the results obtained from the tests is performed.

  5. Challenges for micro-scale flapping-wing micro air vehicles

    NASA Astrophysics Data System (ADS)

    Wood, Robert J.; Finio, Benjamin; Karpelson, Michael; Pérez-Arancibia, Nestor O.; Sreetharan, Pratheev; Whitney, John P.

    2012-06-01

    The challenges for successful flight of insect-scale micro air vehicles encompass basic questions of fabrication, design, propulsion, actuation, control, and power - topics that have in general been answered for larger aircraft. When developing a flying robot on the scale of flies and bees, all hardware must be developed from scratch as there are no "off-the-shelf" sensors, actuators, or microcontrollers that can satisfy the extreme mass and power limitations imposed by such vehicles. Similar challenges exist for fabrication and assembly of the structural and aeromechanical components of insect-scale micro air vehicles that neither macro-scale techniques nor MEMS can adequately solve. With these challenges in mind, this paper presents progress in the essential technologies for micro-scale flapping-wing robots.

  6. CRITERIA AND AIR TOXIC EMISSIONS FROM IN-USE, LOW EMISSION VEHICLES (LEVS)

    EPA Science Inventory

    The U.S. Environmental Protection Agency implemented a program to identify tailpipe emissions of criteria and air toxic contaminants from in-use, light-duty Low Emission Vehicles (LEVs). EPA recruited twenty-five LEVs in 2002, and measured emissions on a chassis dynamometer usin...

  7. Rehabilitation of the Rocket Vehicle Integration Test Stand at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.; Ray, Ronald J.; Phillips, Paul

    2005-01-01

    Since initial use in 1958 for the X-15 rocket-powered research airplane, the Rocket Engine Test Facility has proven essential for testing and servicing rocket-powered vehicles at Edwards Air Force Base. For almost two decades, several successful flight-test programs utilized the capability of this facility. The Department of Defense has recently demonstrated a renewed interest in propulsion technology development with the establishment of the National Aerospace Initiative. More recently, the National Aeronautics and Space Administration is undergoing a transformation to realign the organization, focusing on the Vision for Space Exploration. These initiatives provide a clear indication that a very capable ground-test stand at Edwards Air Force Base will be beneficial to support the testing of future access-to-space vehicles. To meet the demand of full integration testing of rocket-powered vehicles, the NASA Dryden Flight Research Center, the Air Force Flight Test Center, and the Air Force Research Laboratory have combined their resources in an effort to restore and upgrade the original X-15 Rocket Engine Test Facility to become the new Rocket Vehicle Integration Test Stand. This report describes the history of the X-15 Rocket Engine Test Facility, discusses the current status of the facility, and summarizes recent efforts to rehabilitate the facility to support potential access-to-space flight-test programs. A summary of the capabilities of the facility is presented and other important issues are discussed.

  8. Cushion System for Multi-Use Child Safety Seat

    NASA Technical Reports Server (NTRS)

    Dabney, Richard W. (Inventor); Elrod, Susan V. (Inventor)

    2007-01-01

    A cushion system for use with a child safety seat has a plurality of bladders assembled to form a seat cushion that cooperates with the seat's safety harness. One or more sensors coupled to the safety harness sense tension therein and generate a signal indicative of the tension. Each of the bladders is individually pressurized by a pressurization system to define a support configuration of the seat cushion. The pressurization system is disabled when tension in the safety harness has attained a threshold level.

  9. Cushion system for multi-use child safety seat

    NASA Technical Reports Server (NTRS)

    Dabney, Richard W. (Inventor); Elrod, Susan V. (Inventor)

    2007-01-01

    A cushion system for use with a child safety seat has a plurality of bladders assembled to form a seat cushion that cooperates with the seat's safety harness. One or more sensors coupled to the safety harness sense tension therein and generate a signal indicative of the tension. Each of the bladders is individually pressurized by a pressurization system to define a support configuration of the seat cushion. The pressurization system is disabled when tension in the safety harness has attained a threshold level.

  10. 7 CFR 1785.68 - Establishing an RUS cushion of credit payment account.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Establishing an RUS cushion of credit payment account... FOR ELECTRIC AND TELEPHONE BORROWERS RUS Cushion of Credit Account Computations and Procedures 1785.68 Establishing an RUS cushion of credit payment account. A cushion of credit account shall...

  11. 7 CFR 1785.68 - Establishing an RUS cushion of credit payment account.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Establishing an RUS cushion of credit payment account... FOR ELECTRIC AND TELEPHONE BORROWERS RUS Cushion of Credit Account Computations and Procedures 1785.68 Establishing an RUS cushion of credit payment account. A cushion of credit account shall...

  12. 7 CFR 1785.68 - Establishing an RUS cushion of credit payment account.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Establishing an RUS cushion of credit payment account... FOR ELECTRIC AND TELEPHONE BORROWERS RUS Cushion of Credit Account Computations and Procedures 1785.68 Establishing an RUS cushion of credit payment account. A cushion of credit account shall...

  13. 7 CFR 1785.68 - Establishing an RUS cushion of credit payment account.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Establishing an RUS cushion of credit payment account... FOR ELECTRIC AND TELEPHONE BORROWERS RUS Cushion of Credit Account Computations and Procedures 1785.68 Establishing an RUS cushion of credit payment account. A cushion of credit account shall...

  14. Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design

    NASA Technical Reports Server (NTRS)

    Runkle, R. E.; Drobnik, R. F.

    1979-01-01

    The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

  15. An Air-Launched Low-Cost Launch Vehicle

    NASA Astrophysics Data System (ADS)

    Hudson, Gary C.

    2005-02-01

    The QuickReach concept is a responsive, mobile, air-launched, two-stage liquid pressure-fed rocket that is capable of placing nearly 2,000 pounds into low earth orbit. The rocket is extracted from a transport aircraft using gravity and a small drogue parachute for orientation stabilization. The design of the container holding the rocket allows the use of existing transport aircraft without any modification. Propulsion is LOX and propane using the Vapak concept for tank pressurization. Structures make use of advanced composites.

  16. The Effects of Body Mass Composition and Cushion Type on Seat-Interface Pressure in Spinal Cord Injured Patients

    PubMed Central

    Cho, Kang Hee; Beom, Jaewon; Yuk, Jee Hyun

    2015-01-01

    Objective To investigate the effects of body mass composition and cushion type on seat-interface pressure in spinal cord injured (SCI) patients and healthy subjects. Methods Twenty SCI patients and control subjects were included and their body mass composition measured. Seat-interface pressure was measured with participants in an upright sitting posture on a wheelchair with three kinds of seat cushion and without a seat cushion. We also measured the pressure with each participant in three kinds of sitting postures on each air-filled cushion. We used repeated measure ANOVA, the Mann-Whitney test, and Spearman correlation coefficient for statistical analysis. Results The total skeletal muscle mass and body water in the lower extremities were significantly higher in the control group, whilst body fat was significantly higher in the SCI group. However, the seat-interface pressure and body mass composition were not significantly correlated in both groups. Each of the three types of seat cushion resulted in significant reduction in the seat-interface pressure. The SCI group had significantly higher seatinterface pressure than the control group regardless of cushion type or sitting posture. The three kinds of sitting posture did not result in a significant reduction of seat-interface pressure. Conclusion We confirmed that the body mass composition does not have a direct effect on seat-interface pressure. However, a reduction of skeletal muscle mass and body water can influence the occurrence of pressure ulcers. Furthermore, in order to minimize seat-interface pressure, it is necessary to apply a method fitted to each individual rather than a uniform method. PMID:26798612

  17. Geometry Modeling and Adaptive Control of Air-Breathing Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Vick, Tyler Joseph

    Air-breathing hypersonic vehicles have the potential to provide global reach and affordable access to space. Recent technological advancements have made scramjet-powered flight achievable, as evidenced by the successes of the X-43A and X-51A flight test programs over the last decade. Air-breathing hypersonic vehicles present unique modeling and control challenges in large part due to the fact that scramjet propulsion systems are highly integrated into the airframe, resulting in strongly coupled and often unstable dynamics. Additionally, the extreme flight conditions and inability to test fully integrated vehicle systems larger than X-51 before flight leads to inherent uncertainty in hypersonic flight. This thesis presents a means to design vehicle geometries, simulate vehicle dynamics, and develop and analyze control systems for hypersonic vehicles. First, a software tool for generating three-dimensional watertight vehicle surface meshes from simple design parameters is developed. These surface meshes are compatible with existing vehicle analysis tools, with which databases of aerodynamic and propulsive forces and moments can be constructed. A six-degree-of-freedom nonlinear dynamics simulation model which incorporates this data is presented. Inner-loop longitudinal and lateral control systems are designed and analyzed utilizing the simulation model. The first is an output feedback proportional-integral linear controller designed using linear quadratic regulator techniques. The second is a model reference adaptive controller (MRAC) which augments this baseline linear controller with an adaptive element. The performance and robustness of each controller are analyzed through simulated time responses to angle-of-attack and bank angle commands, while various uncertainties are introduced. The MRAC architecture enables the controller to adapt in a nonlinear fashion to deviations from the desired response, allowing for improved tracking performance, stability, and robustness.

  18. 21 CFR 874.1100 - Earphone cushion for audiometric testing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1100 Earphone cushion for... connection path) between the audiometer earphone and the patient's ear. (b) Classification. Class I...

  19. 21 CFR 874.1100 - Earphone cushion for audiometric testing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1100 Earphone cushion for... connection path) between the audiometer earphone and the patient's ear. (b) Classification. Class I...

  20. 21 CFR 874.1100 - Earphone cushion for audiometric testing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1100 Earphone cushion for... connection path) between the audiometer earphone and the patient's ear. (b) Classification. Class I...

  1. 21 CFR 874.1100 - Earphone cushion for audiometric testing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1100 Earphone cushion for... connection path) between the audiometer earphone and the patient's ear. (b) Classification. Class I...

  2. 21 CFR 874.1100 - Earphone cushion for audiometric testing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) MEDICAL DEVICES EAR, NOSE, AND THROAT DEVICES Diagnostic Devices § 874.1100 Earphone cushion for... connection path) between the audiometer earphone and the patient's ear. (b) Classification. Class I...

  3. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...-counter. (b) Classification. (1) Class I if the device is made of wax-impregnated cotton cloth that the... denture cushion or pad is made of a material other than wax-impregnated cotton cloth or if the...

  4. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...-counter. (b) Classification. (1) Class I if the device is made of wax-impregnated cotton cloth that the... denture cushion or pad is made of a material other than wax-impregnated cotton cloth or if the...

  5. Performance Validation Approach for the GTX Air-Breathing Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.; Roche, Joseph M.

    2002-01-01

    The primary objective of the GTX effort is to determine whether or not air-breathing propulsion can enable a launch vehicle to achieve orbit in a single stage. Structural weight, vehicle aerodynamics, and propulsion performance must be accurately known over the entire flight trajectory in order to make a credible assessment. Structural, aerodynamic, and propulsion parameters are strongly interdependent, which necessitates a system approach to design, evaluation, and optimization of a single-stage-to-orbit concept. The GTX reference vehicle serves this purpose, by allowing design, development, and validation of components and subsystems in a system context. The reference vehicle configuration (including propulsion) was carefully chosen so as to provide high potential for structural and volumetric efficiency, and to allow the high specific impulse of air-breathing propulsion cycles to be exploited. Minor evolution of the configuration has occurred as analytical and experimental results have become available. With this development process comes increasing validation of the weight and performance levels used in system performance determination. This paper presents an overview of the GTX reference vehicle and the approach to its performance validation. Subscale test rigs and numerical studies used to develop and validate component performance levels and unit structural weights are outlined. The sensitivity of the equivalent, effective specific impulse to key propulsion component efficiencies is presented. The role of flight demonstration in development and validation is discussed.

  6. A fast ascent trajectory optimization method for hypersonic air-breathing vehicles

    NASA Astrophysics Data System (ADS)

    Murillo, Oscar J., Jr.

    The objective of this dissertation is to investigate a fast and reliable method to generate three-dimensional optimal ascent trajectories for hypersonic air-breathing vehicles. The problem is notoriously difficult because of the strong nonlinear coupling amongst aerodynamics, propulsion, vehicle attitude and trajectory state. As such an algorithm matures, the ultimate goal is to realize optimal closed-loop ascent guidance for hypersonic air-breathing vehicles. The problem is formulated as a fuel-optimal control problem. The corresponding necessary conditions are given. It is shown how the original problem of search for the optimal control commands can be reduced to a univariate root-finding problem at each point along the trajectory. A finite difference scheme is used to numerically solve the associated two-point-boundary-value problem. Evaluation of the approach is done through open-loop solutions and closed-loop simulations. The results show promising potential of the proposed approach as a rapid trajectory optimization tool for the class of hypersonic air-breathing vehicles.

  7. Impact of aeroelasticity on propulsion and longitudinal flight dynamics of an air-breathing hypersonic vehicle

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Mcminn, John D.; Pototzky, Anthony S.; Wooley, Christine L.

    1993-01-01

    Many air-breathing hypersonic aerospacecraft design concepts incorporate an elongated fuselage forebody acting as the aerodynamic compression surface for a hypersonic combustion module, or scram jet. This highly integrated design approach creates the potential for an unprecedented form of aero-propulsive-elastic interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the rigid body flight dynamics and/or further excite the fuselage bending modes. To investigate the potential for such interactions, a math model was developed which included the longitudinal flight dynamics, propulsion system, and first seven elastic modes of a hypersonic air-breathing vehicle. Perturbation time histories from a simulation incorporating this math model are presented that quantify the propulsive force and moment variations resulting from aeroelastic vehicle deflections. Root locus plots are presented to illustrate the effect of feeding the propulsive perturbations back into the aeroelastic model. A concluding section summarizes the implications of the observed effects for highly integrated hypersonic air-breathing vehicle concepts.

  8. Effect of Vehicle type on the Performance of Second Generation Air Bags for Child Occupants

    PubMed Central

    Arbogast, Kristy B.; Durbin, Dennis R.; Kallan, Michael J.; Winston, Flaura K.

    2003-01-01

    Passenger air bags experienced considerable design modification in the late 1990s, principally to mitigate risks to child passengers. This study utilized Data from the Partners for Child Passenger Safety study, a large-scale child-focused crash surveillance system, to examine the effect of vehicle type on the differential performance of first and second generation air bags on injuries to restrained children in frontal impact crashes. Our results show that the benefit of second-generation air bags was seen in passenger cars those children exposed to second-generation air bags were half as likely to sustain a serious injury and minivans. However, in SUVs the data suggest no reduction in injury risk with the new designs. This field data provides crucial real-world experience to the automotive industry as they work towards the next generation of air bag designs. PMID:12941218

  9. Determining air quality and greenhouse gas impacts of hydrogen infrastructure and fuel cell vehicles.

    PubMed

    Stephens-Romero, Shane; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald; Samuelsen, Scott

    2009-12-01

    Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario). PMID:19943683

  10. Thermal performance of aircraft polyurethane seat cushions

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1982-01-01

    Measurements were conducted on 7.6 x 7.6 cm samples of polyurethane seat cushion material in a modified National Bureau of Standards smoke density chamber to simulate real life conditions for an onboard aircraft fire or post-crash fire. In this study, a non-flaming heat radiation condition was simulated. Two aluminized polymeric fabrics (Norfab 11HT-26-A and Preox 1100-4) and one neoprene type material in two thicknesses (Vonar 2 and 3) were tested as heat blocking layers to protect the urethane foam from rapid heat degradation. Thermogravimetric analysis and differential scanning calorimetry were performed to characterize thermally the materials tested. It was found that Vonar 2 or 3 provided approximately equal thermal protection to F.R. urethane as the aluminized fabrics, but at a significant weight penalty. The efficiency of the foams to absorb heat per unit mass loss when protected with the heat blocking layer decreases in the heating range of 2.5-5.0 W/sq cm, but remains unchanged or slightly increases in the range of 5.0-7.5 W/sq cm. The results show that at all heat flux ranges tested the usage of a heat blocking layer in aircraft seats significantly improves their thermal performance.

  11. Cleaning the Air and Improving Health with Hydrogen Fuel-Cell Vehicles

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2005-06-01

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

  12. Orbit-on-demand vehicle propelled by air-turborocket/ramjet engines

    NASA Technical Reports Server (NTRS)

    Hartung, L.; Karkow, J.; Ordway, W.; Pickett, D.; Muras, A.

    1986-01-01

    A preliminary design study has been completed for a fully reusable, single-stage-to-orbit transatmospheric vehicle. The specified mission capability was to lift a 20,000 lb payload to low earth orbit. A ground accelerator-assisted horizontal take-off was chosen to increase operational flexibility. The multi-mode propulsion system included the use of air-turborocket, ramjet, scramjet and rocket engines. Weight and performance estimates were obtained for the vehicle. A computer package was developed to perform aerothermodynamic analyses of the propulsion modes throughout the flight environment from take-off to low earth orbit. Results are presented for a semi-optimized trajectory. The analysis indicates that a vehicle of this type has great potential for providing low cost, flexible access to space.

  13. Interagency Workshop on Lighter than Air Vehicles, Monterey, Calif., September 9-13, 1974, Proceedings

    NASA Technical Reports Server (NTRS)

    Vittek, J. F., Jr.

    1975-01-01

    Papers are presented which review modern lighter-than-air (LTA) airship design concepts and LTA structures and materials technology, as well as perform economic and market analyses for assessment of the viability of future LTA development programs. Potential applications of LTA vehicles are examined. Some of the topics covered include preliminary estimates of operating costs for LTA transports, an economic comparison of three heavy lift airborn systems, boundary layer control for airships, computer aided flexible envelope designs, state-of-the-art of metalclad airships, aspects of hybrid-Zeppelins, the LTA vehicle as a total cargo system, unmanned powered balloons, and a practical concept for powered or tethered weight-lifting LTA vehicles. Individual items are announced in this issue.

  14. Design and analysis of biomimetic joints for morphing of micro air vehicles.

    PubMed

    Grant, Daniel T; Abdulrahim, Mujahid; Lind, Rick

    2010-12-01

    Flight capability for micro air vehicles is rapidly maturing throughout the aviation community; however, mission capability has not yet matured at the same pace. Maintaining trim during a descent or in the presence of crosswinds remains challenging for fixed-wing aircraft but yet is routinely performed by birds. This paper presents an overview of designs that incorporate morphing to enhance their flight characteristics. In particular, a series of joints and structures is adopted from seagulls to alter either the dihedral or sweep of the wings and thus alter the flight characteristics. The resulting vehicles are able to trim with significantly increased angles of attack and sideslip compared to traditional fixed-wing vehicles. PMID:21098958

  15. Orbit-on-demand vehicle propelled by air-turborocket/ramjet engines

    NASA Astrophysics Data System (ADS)

    Hartung, L.; Karkow, J.; Ordway, W.; Pickett, D.; Muras, A.

    1986-06-01

    A preliminary design study has been completed for a fully reusable, single-stage-to-orbit transatmospheric vehicle. The specified mission capability was to lift a 20,000 lb payload to low earth orbit. A ground accelerator-assisted horizontal take-off was chosen to increase operational flexibility. The multi-mode propulsion system included the use of air-turborocket, ramjet, scramjet and rocket engines. Weight and performance estimates were obtained for the vehicle. A computer package was developed to perform aerothermodynamic analyses of the propulsion modes throughout the flight environment from take-off to low earth orbit. Results are presented for a semi-optimized trajectory. The analysis indicates that a vehicle of this type has great potential for providing low cost, flexible access to space.

  16. The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Stargel, D. S.

    2012-01-01

    Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

  17. Cleaning the air and improving health with hydrogen fuel-cell vehicles.

    PubMed

    Jacobson, M Z; Colella, W G; Golden, D M

    2005-06-24

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline. PMID:15976300

  18. Intersociety Advanced Marine Vehicles Conference and Exhibit, Arlington, VA, June 5-7, 1989, Technical Papers

    NASA Astrophysics Data System (ADS)

    The present conference on advanced marine vehicles discusses advancements in surface-effect ship (SES) technologies, small waterplane-area twin-hull (SWATH) ship operations, advanced marine vehicle concepts, ocean systems and subsurface vehicles, air-cushion vehicle (ACV) concepts, seaplane technologies, advanced hull hydrodynamics, wing-in-ground effect (WIGE) aircraft, competition-craft aerodynamics, and marine propulsion. Attention is given to military applications of the 'NES 200' SES platform, experiences over 16 years of SWATH ship operations, hydrofoil catamarans for military and civilian applications, SES passenger ferries for the N.Y.C. metropolitan area, advanced submarine concepts, parametric studies in SWATH ship design, ACV experience in Antarctica, the CL-215 seaplane, large-scale WIGE vehicles, an ocean spacecraft-launch facility, an ACV Arctic icebreaker, and 'marinizing' methods for gas turbine engines.

  19. An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    1999-01-01

    The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

  20. Flexible Wing Base Micro Aerial Vehicles: Towards Flight Autonomy: Vision-Based Horizon Detection for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Nechyba, Michael C.; Ettinger, Scott M.; Ifju, Peter G.; Wazak, Martin

    2002-01-01

    Recently substantial progress has been made towards design building and testifying remotely piloted Micro Air Vehicles (MAVs). This progress in overcoming the aerodynamic obstacles to flight at very small scales has, unfortunately, not been matched by similar progress in autonomous MAV flight. Thus, we propose a robust, vision-based horizon detection algorithm as the first step towards autonomous MAVs. In this paper, we first motivate the use of computer vision for the horizon detection task by examining the flight of birds (biological MAVs) and considering other practical factors. We then describe our vision-based horizon detection algorithm, which has been demonstrated at 30 Hz with over 99.9% correct horizon identification, over terrain that includes roads, buildings large and small, meadows, wooded areas, and a lake. We conclude with some sample horizon detection results and preview a companion paper, where the work discussed here forms the core of a complete autonomous flight stability system.

  1. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    PubMed

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. PMID:24997256

  2. A Predictive Model for Vehicle Air Exchange Rates based on a Large, Representative Sample

    PubMed Central

    Fruin, Scott A.; Hudda, Neelakshi; Sioutas, Constantinos; Delfino, Ralph J.

    2014-01-01

    The in-vehicle microenvironment is an important route of exposure to traffic-related pollutants, particularly ultrafine particles. However, significant particle losses can occur under conditions of low air exchange rate (AER) when windows are closed and air is recirculating. AERs are lower for newer vehicles and at lower speeds. Despite the importance of AER in affecting in-vehicle particle exposures, few studies have characterized AER and all have tested only a small number of cars. One reason for this is the difficulty in measuring AER with tracer gases such as SF6 the most common method. We developed a simplified yet accurate method for determining AER using the occupants own production of CO2 a convenient compound to measure. By measuring initial CO2 build-up rates and equilibrium values of CO2 at fixed speeds, AER was calculated for 59 vehicles representative of Californias fleet. AER measurements correlated and agreed well with the largest other study conducted (R2=0.83). Multi-variable models captured 70% of the variability in observed AER using only age, mileage, manufacturer and speed. These results will be useful to exposure and epidemiological studies since all model variable values are easily obtainable through questionnaire. PMID:21428392

  3. LTA in the USA - Here's where it stands today. [lighter than air vehicles

    NASA Technical Reports Server (NTRS)

    Vittek, J. F., Jr.

    1974-01-01

    Lighter than air (LTA) vehicles were the first aircraft to fly and, until the disasters of the 1930s, were thought by many to be the primary mode of air transport. The history of LTA in the United States is briefly traced and the reasons for the current revival in interest are discussed. The focal point for this revival was the LTA Workshop hosted by M.I.T. under the joint sponsorship of the United States National Aeronautics and Space Administration, Navy, Federal Aviation Administration and Department of Transportation. The Workshop and its results are discussed in detail.

  4. The system integration and verification testing of an orbital maneuvering vehicle for an air bearing floor

    NASA Technical Reports Server (NTRS)

    Shields, N. L., Jr.; Martin, M. F.; Paulukaitis, K. R.; Haslam, J. W., Jr.; Henderson, D. E.

    1986-01-01

    The teleoperator and Robotics Evaluation Facility (TOREF) is composed of a 4,000 square foot precision air bearing floor, the Teleoperator Motion Base, the Target Motion and Support Simulator, the mock-ups of the Hubble Space Telescope, Multi-mission Modular Spacecraft, and the Orbital Maneuvering Vehicle (OMV). The TOREF and its general capabilities to support the OMV and other remote system simulations; the facility operating procedures and requirements; and the results of generic OMV investigations are summarized.

  5. A hybrid approach to modeling and control of vehicle height for electronically controlled air suspension

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Wang, Shaohua; Liu, Yanling; Chen, Long

    2015-12-01

    The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

  6. A hybrid approach to modeling and control of vehicle height for electronically controlled air suspension

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Wang, Shaohua; Liu, Yanling; Chen, Long

    2016-01-01

    The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

  7. Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

    NASA Astrophysics Data System (ADS)

    Wang, J. M.; Jeong, C.-H.; Zimmerman, N.; Healy, R. M.; Wang, D. K.; Ke, F.; Evans, G. J.

    2015-08-01

    An automated identification and integration method has been developed for in-use vehicle emissions under real-world conditions. This technique was applied to high-time-resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada, during four seasons, through month-long campaigns in 2013-2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number; black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline-dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg fuel-1 and 7.5 × 1014 # kg fuel-1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25 %) contributed significantly to total fleet emissions: 100, 100, 81, and 77 % for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter; however, regulatory strategies to more efficiently target multi-pollutant mixtures may be better developed by considering the co-emitted pollutants as well.

  8. Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

    NASA Astrophysics Data System (ADS)

    Wang, J. M.; Jeong, C.-H.; Zimmerman, N.; Healy, R. M.; Wang, D. K.; Ke, F.; Evans, G. J.

    2015-03-01

    An automated identification and integration method has been developed to investigate in-use vehicle emissions under real-world conditions. This technique was applied to high time resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada during four seasons, through month-long campaigns in 2013-2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg-1 and 7.7 × 1014 kg-1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25%) contributed significantly to total fleet emissions; 95, 93, 76, and 75% for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter. However, regulatory strategies to more efficiently target multi-pollutants mixtures may be better developed by considering the co-emitted pollutants as well.

  9. Improving the accuracy of vehicle emissions profiles for urban transportation greenhouse gas and air pollution inventories.

    PubMed

    Reyna, Janet L; Chester, Mikhail V; Ahn, Soyoung; Fraser, Andrew M

    2015-01-01

    Metropolitan greenhouse gas and air emissions inventories can better account for the variability in vehicle movement, fleet composition, and infrastructure that exists within and between regions, to develop more accurate information for environmental goals. With emerging access to high quality data, new methods are needed for informing transportation emissions assessment practitioners of the relevant vehicle and infrastructure characteristics that should be prioritized in modeling to improve the accuracy of inventories. The sensitivity of light and heavy-duty vehicle greenhouse gas (GHG) and conventional air pollutant (CAP) emissions to speed, weight, age, and roadway gradient are examined with second-by-second velocity profiles on freeway and arterial roads under free-flow and congestion scenarios. By creating upper and lower bounds for each factor, the potential variability which could exist in transportation emissions assessments is estimated. When comparing the effects of changes in these characteristics across U.S. cities against average characteristics of the U.S. fleet and infrastructure, significant variability in emissions is found to exist. GHGs from light-duty vehicles could vary by -2%-11% and CAP by -47%-228% when compared to the baseline. For heavy-duty vehicles, the variability is -21%-55% and -32%-174%, respectively. The results show that cities should more aggressively pursue the integration of emerging big data into regional transportation emissions modeling, and the integration of these data is likely to impact GHG and CAP inventories and how aggressively policies should be implemented to meet reductions. A web-tool is developed to aide cities in improving emissions uncertainty. PMID:25438089

  10. Vibration Suppression of Car-Body Tilting Vehicle Using Air Springs with Antiroll Damper

    NASA Astrophysics Data System (ADS)

    Tanifuji, Katsuya; Saito, Mitsuru; Soma, Hitoshi; Ishii, Takumi; Kajitani, Yasushi

    In recent years, air-spring-type tilting vehicles, which use air springs as the car-body tilt mechanism, have been employed, even in Shinkansen trains, to increase the operation speed on curved sections. On a test train running at a speed of about 300 km/h with the tilt mechanism, however, it was found that the car-body roll and lateral vibrations increased in compound curves where the plane and vertical curves overlapped. In this study, an analytical model of the air-spring-type tilting vehicle is developed, and a numerical simulation is carried out to clarify the high-speed curving behavior in a compound curve. Then an antiroll damper, which is installed between the car-body and the existing anti-rolling device, is examined as a countermeasure to reduce car-body vibration. As a result, it is shown that the vibration occurring in the compound curve is caused by the centrifugal force generated by the passage of the train on the vertical curve and the imbalance in stiffness between the left and right air springs during tilting. It is also shown that an antiroll damper has a potential to suppress the increase in car-body vibration in compound curves.

  11. Landing Characteristics of a Re-entry Vehicle with Canted Multiple Air Bag Load Alleviation System

    NASA Technical Reports Server (NTRS)

    1963-01-01

    Investigation of the Landing Characteristics of a Re-entry Vehicle Having a Canted Multiple Air Bag Load Alleviation System. An investigation was made to determine the landing-impact characteristics of a reentry vehicle having a multiple-air-bag load-alleviation system. A 1/16-scale dynamic model having four canted air bags was tested at flight-path angles of 90 degrees (vertical), 45 degrees, and 27 degrees for a parachute or paraglider vertical letdown velocity of 30 feet per second (full scale). Landings were made on concrete at attitudes ranging from -l5 degrees to 20 degrees. The friction coefficient between the model heat shield and the concrete was approximately 0.4. An aluminum diaphragm, designed to rupture at 10.8 pounds per square inch gage, was used to maintain initial pressure in the air bags for a short time period. [Entire movie available on DVD from CASI as Doc ID 20070030986. Contact help@sti.nasa.gov

  12. Air quality and climate impacts due to CNG conversion of motor vehicles in Dhaka, Bangladesh.

    PubMed

    Wadud, Zia; Khan, Tanzila

    2013-12-17

    Dhaka had recently experienced rapid conversion of its motor vehicle fleet to run on compressed natural gas (CNG). This paper quantifies ex-post the air quality and climate benefits of the CNG conversion policy, including monetary valuations, through an impact pathway approach. Around 2045 (1665) avoided premature deaths in greater Dhaka (City Corporation) can be attributed to air quality improvements from the CNG conversion policy in 2010, resulting in a saving of around USD 400 million. Majority of these health benefits resulted from the conversion of high-emitting diesel vehicles. CNG conversion was clearly detrimental from climate change perspective using the changes in CO2 and CH4 only (CH4 emissions increased); however, after considering other global pollutants (especially black carbon), the climate impact was ambiguous. Uncertainty assessment using input distributions and Monte Carlo simulation along with a sensitivity analysis show that large uncertainties remain for climate impacts. For our most likely estimate, there were some climate costs, valued at USD 17.7 million, which is an order of magnitude smaller than the air quality benefits. This indicates that such policies can and should be undertaken on the grounds of improving local air pollution alone and that precautions should be taken to reduce the potentially unintended increases in GHG emissions or other unintended effects. PMID:24195736

  13. High Altitude Long Endurance Air Vehicle Analysis of Alternatives and Technology Requirements Development

    NASA Technical Reports Server (NTRS)

    Nickol, Craig L.; Guynn, Mark D.; Kohout, Lisa L.; Ozoroski, Thomas A.

    2007-01-01

    The objective of this study was to develop a variety of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV) conceptual designs for two operationally useful missions (hurricane science and communications relay) and compare their performance and cost characteristics. Sixteen potential HALE UAV configurations were initially developed, including heavier-than-air (HTA) and lighter-than-air (LTA) concepts with both consumable fuel and solar regenerative (SR) propulsion systems. Through an Analysis of Alternatives (AoA) down select process, the two leading consumable fuel configurations (one each from the HTA and LTA alternatives) and an HTA SR configuration were selected for further analysis. Cost effectiveness analysis of the consumable fuel configurations revealed that simply maximizing vehicle endurance can lead to a sub-optimum system solution. An LTA concept with a hybrid propulsion system (solar arrays and a hydrogen-air proton exchange membrane fuel cell) was found to have the best mission performance; however, an HTA diesel-fueled wing-body-tail configuration emerged as the preferred consumable fuel concept because of the large size and technical risk of the LTA concept. The baseline missions could not be performed by even the best HTA SR concept. Mission and SR technology trade studies were conducted to enhance understanding of the potential capabilities of such a vehicle. With near-term technology SR-powered HTA vehicles are limited to operation in favorable solar conditions, such as the long days and short nights of summer at higher latitudes. Energy storage system specific energy and solar cell efficiency were found to be the key technology areas for enhancing HTA SR performance.

  14. Design of permanent magnet brushless motors with asymmetric air gap for electric vehicles

    NASA Astrophysics Data System (ADS)

    Chau, K. T.; Cui, Wei; Jiang, J. Z.; Wang, Zheng

    2006-04-01

    This paper proposes a cost-effective approach to design permanent magnet brushless dc motors for electric vehicles. The key is to shape the pole arc in such a way that the air gap length is at a maximum at the leading edge of each rotor pole arc and at a minimum at the trailing edge of the same pole arc, hence resulting in an asymmetric air gap. Thus, for a specified rotational direction, the distortion of air gap flux density and hence the torque ripple can be significantly suppressed. Also, with the use of advanced conduction angle control, the motor can achieve a wide speed range. The proposed motor drive is designed and implemented for a low-voltage battery-powered electric motorcycle.

  15. Air Bearing for Small Planar Vibrations

    NASA Technical Reports Server (NTRS)

    Wolf, M. F.

    1985-01-01

    Air-cushion device provides vibrations along axes 90 degrees apart. Bearing includes movable slide sandwiched between two fixed support plates. Separation between plates adjusted to standard air-bearing tolerances. Pressurized air supplied to slide so it floats between plates on cushion of air. Air exhausts on top and bottom surfaces of three arms of slide. Developed for stirring crystal-growth liquids in containers.

  16. Lightweight, fire-retardant, crashworthy aircraft seat cushioning

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A.; Mcdonough, Paul T.

    1991-01-01

    A two page discussion of non-aerospace seating applications and the design of NASA's safety seat cushioning (SSC) is presented. The SSC was designed for both safety and comfort in order to replace polyurethane cushioning which is flammable and produces lethal fumes upon combustion. The SSC is composed of advanced fabric reinforced composites and is lightweight, fire-retardent, and crashworthy. The seat design consists of central elliptical tubular spring supports made of fire-resistant and fatigue-durable composites surrounded by a fire-blocking sheath. The cushioning is made crashworthy by incorporating energy-absorbing, viscoelastic layers between the nested, elliptical-hoop springs. The design is intended to provide comfortable seating that meets aircraft-loading requirements without using the conventional polyurethane materials. The designs of an aircraft seat and structural components of the SSC are also presented.

  17. Design of a Flush Airdata System (FADS) for the Hypersonic Air Launched Option (HALO) Vehicle

    NASA Technical Reports Server (NTRS)

    Whitmore, Stephen A.; Moes, Timothy R.; Deets, Dwain A. (Technical Monitor)

    1994-01-01

    This paper presents a design study for a pressure based Flush airdata system (FADS) on the Hypersonic Air Launched Option (HALO) Vehicle. The analysis will demonstrate the feasibility of using a pressure based airdata system for the HALO and provide measurement uncertainty estimates along a candidate trajectory. The HALO is a conceived as a man-rated vehicle to be air launched from an SR-71 platform and is proposed as a testbed for an airbreathing hydrogen scramjet. A feasibility study has been performed and indicates that the proposed trajectory is possible with minimal modifications to the existing SR71 vehicle. The mission consists of launching the HALO off the top of an SR-71 at Mach 3 and 80,000 ft. A rocket motor is then used to accelerate the vehicle to the test condition. After the scramjet test is completed the vehicle will glide to a lakebed runway landing. This option provides reusability of the vehicle and scramjet engine. The HALO design will also allow for various scramjet engine and flowpath designs to be flight tested. For the HALO flights, measurements of freestream airdata are considered to be a mission critical to perform gain scheduling and trajectory optimization. One approach taken to obtaining airdata involves measurement of certain parameters such as external atmospheric winds, temperature, etc to estimate the airdata quantities. This study takes an alternate approach. Here the feasibility of obtaining airdata using a pressure-based flush airdata system (FADS) methods is assessed. The analysis, although it is performed using the HALO configuration and trajectory, is generally applicable to other hypersonic vehicles. The method to be presented offers the distinct advantage of inferring total pressure, Mach number, and flow incidence angles, without stagnating the freestream flow. This approach allows for airdata measurements to be made using blunt surfaces and significantly diminishes the heating load at the sensor. In the FADS concept a matrix of flush ports is placed in the vicinity of the aircraft nose, and the airdata are inferred indirectly from the measured pressures.

  18. Interactions between Flight Dynamics and Propulsion Systems of Air-Breathing Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Dalle, Derek J.

    The development and application of a first-principles-derived reduced-order model called MASIV (Michigan/AFRL Scramjet In Vehicle) for an air-breathing hypersonic vehicle is discussed. Several significant and previously unreported aspects of hypersonic flight are investigated. A fortunate coupling between increasing Mach number and decreasing angle of attack is shown to extend the range of operating conditions for a class of supersonic inlets. Detailed maps of isolator unstart and ram-to-scram transition are shown on the flight corridor map for the first time. In scram mode the airflow remains supersonic throughout the engine, while in ram mode there is a region of subsonic flow. Accurately predicting the transition between these two modes requires models for complex shock interactions, finite-rate chemistry, fuel-air mixing, pre-combustion shock trains, and thermal choking, which are incorporated into a unified framework here. Isolator unstart occurs when the pre-combustion shock train is longer than the isolator, which blocks airflow from entering the engine. Finally, cooptimization of the vehicle design and trajectory is discussed. An optimal control technique is introduced that greatly reduces the number of computations required to optimize the simulated trajectory.

  19. Prospects for utilization of air liquefaction and enrichment system (ALES) propulsion in fully reusable launch vehicles

    NASA Astrophysics Data System (ADS)

    Bond, W. H.; Yi, A. C.

    1993-06-01

    A concept is shown for a fully reusable, earth to orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high speed acceleration, both using LH2 fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90 percent pure LOX that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to Mach 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. The paper shows an approach and the corresponding technology needs for using ALES propulsion in a SSTO vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, is critical to meet the structure weight objective for SSTO. Configurations that utilize 'waverider' aerodynamics show great promise to reduce the vehicle weight.

  20. Prospects for utilization of air liquefaction and enrichment system (ALES) propulsion in fully reusable launch vehicles

    NASA Technical Reports Server (NTRS)

    Bond, W. H.; Yi, A. C.

    1993-01-01

    A concept is shown for a fully reusable, earth to orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high speed acceleration, both using LH2 fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90 percent pure LOX that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to Mach 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. The paper shows an approach and the corresponding technology needs for using ALES propulsion in a SSTO vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, is critical to meet the structure weight objective for SSTO. Configurations that utilize 'waverider' aerodynamics show great promise to reduce the vehicle weight.

  1. Mid-Air Retrieval technology for returning of reusable launch vehicles' boosters

    NASA Astrophysics Data System (ADS)

    Antonenko, S. V.; Belavskiy, S. A.

    2009-09-01

    The multilateral analysis of reusable launch vehicles (RLV) has been carried out by the authors' team within 8 years. The studies are based on the world experience and also on the large practical experience of Khrunichev Space Center in designing, production, and operation of aerospacecraft (incuding reentry one). The analysis results are monosemantic and are the following: The only one feasible principle for the nearest future is a mid-air retrieval (MAR), which will permit potentially the creation of the effective RLV. For practical realization of the results obtained, the authors in cooperation with M. L. Mil's Moscow Helicopter Plant (MHP) and "Parachute Design" Scientific Institute have developed the launch vehicles' booster MAR technology (including the structure and principles of main elements formation). The general conclusions of the mar technology are the following: (i) it can be realized with a minimal technical risk at the earliest time (2-3 years); (ii) it can be applied to the existing expendable launch vehicles (ELV) and can be easily adapted to different launch vehicles; (iii) it can be demonstrated at minimal costs and time; and (i?) it permits the creation of the most economically effective RLV (budget savings will be up to 30% and in case of using a special operation technology, the savings can attain 41.5%).

  2. Development of a cushion to prevent ischial pressure sores.

    PubMed Central

    Bowker, P; Davidson, L M

    1979-01-01

    A study was carried out jointly by nursing staff and technologists in an attempt to develop a cushion based on scientific principles and measurement that might prevent pressure sores. At each stage in the development clinical trials were carried out, and using the results of these together with the opinions of medical staff and patients who used the cushion the design was suitably modified. Over four years a seat was evolved that was simple to construct and fulfilled the clinical requirements for a wide range of patients while providing maximum relief of high-pressure points. The design was subsequently taken up commercially. Images Fig 3 PMID:509176

  3. A Method to Control the Cushion Pressure of Oscillating SES

    NASA Astrophysics Data System (ADS)

    Senba, Hiromitsu; Matsuo, Hideo; Takahashi, Hidehiko; Yoshimoto, Shintarou; Matsuo, Kensuke; Kanazawa, Koji; Hiroe, Tetsuyuki; Fujiwara, Kazuhito

    A method is proposed to control the variation of cushion pressure of SES oscillating vertically. The peripheral nozzle is attached along the periphery and swings changing the discharge angle. The angle varies in accordance with the motion of the craft. A method is proposed to analyze the mechanism of this setup. The result is compared with experiments to show the agreement of the two results. It has been shown both theoretically and experimentally that the variation of the cushion pressure is effectively controlled adjusting the amplitude and the phase of the swinging motion of the nozzle.

  4. In-vehicle exposures to particulate air pollution in Canadian metropolitan areas: the urban transportation exposure study.

    PubMed

    Weichenthal, Scott; Van Ryswyk, Keith; Kulka, Ryan; Sun, Liu; Wallace, Lance; Joseph, Lawrence

    2015-01-01

    Commuters may be exposed to increased levels of traffic-related air pollution owing to close proximity to traffic-emissions. We collected in-vehicle and roof-top air pollution measurements over 238 commutes in Montreal, Toronto, and Vancouver, Canada between 2010 and 2013. Voice recordings were used to collect real-time information on traffic density and the presence of diesel vehicles and multivariable linear regression models were used to estimate the impact of these factors on in-vehicle pollutant concentrations (and indoor/outdoor ratios) along with parameters for road type, land use, and meteorology. In-vehicle PM2.5 and NO2 concentrations consistently exceeded regional outdoor levels and each unit increase in the rate of encountering diesel vehicles (count/min) was associated with substantial increases (>100%) in in-vehicle concentrations of ultrafine particles (UFPs), black carbon, and PM2.5 as well as strong increases (>15%) in indoor/outdoor ratios. A model based on meteorology and the length of highway roads within a 500 m buffer explained 53% of the variation in in-vehicle UFPs; however, models for PM2.5 (R(2) = 0.24) and black carbon (R(2) = 0.30) did not perform as well. Our findings suggest that vehicle commuters experience increased exposure to air pollutants and that traffic characteristics, land use, road types, and meteorology are important determinants of these exposures. PMID:25469563

  5. Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

    NASA Technical Reports Server (NTRS)

    Arnold, James O.; Deiwert, George S.

    1997-01-01

    This paper surveys the use of aerothermodynamic facilities which have been useful in the study of external flows and propulsion aspects of hypersonic, air-breathing vehicles. While the paper is not a survey of all facilities, it covers the utility of shock tunnels and conventional hypersonic blow-down facilities which have been used for hypersonic air-breather studies. The problems confronting researchers in the field of aerothermodynamics are outlined. Results from the T5 GALCIT tunnel for the shock-on lip problem are outlined. Experiments on combustors and short expansion nozzles using the semi-free jet method have been conducted in large shock tunnels. An example which employed the NASA Ames 16-Inch shock tunnel is outlined, and the philosophy of the test technique is described. Conventional blow-down hypersonic wind tunnels are quite useful in hypersonic air-breathing studies. Results from an expansion ramp experiment, simulating the nozzle on a hypersonic air-breather from the NASA Ames 3.5 Foot Hypersonic wind tunnel are summarized. Similar work on expansion nozzles conducted in the NASA Langley hypersonic wind tunnel complex is cited. Free-jet air-frame propulsion integration and configuration stability experiments conducted at Langley in the hypersonic wind tunnel complex on a small generic model are also summarized.

  6. Flexible Wing Base Micro Aerial Vehicles: Vision-Guided Flight Stability and Autonomy for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ettinger, Scott M.; Nechyba, Michael C.; Ifju, Peter G.; Wazak, Martin

    2002-01-01

    Substantial progress has been made recently towards design building and test-flying remotely piloted Micro Air Vehicle's (MAVs). We seek to complement this progress in overcoming the aerodynamic obstacles to.flight at very small scales with a vision stability and autonomy system. The developed system based on a robust horizon detection algorithm which we discuss in greater detail in a companion paper. In this paper, we first motivate the use of computer vision for MAV autonomy arguing that given current sensor technology, vision may he the only practical approach to the problem. We then briefly review our statistical vision-based horizon detection algorithm, which has been demonstrated at 30Hz with over 99.9% correct horizon identification. Next we develop robust schemes for the detection of extreme MAV attitudes, where no horizon is visible, and for the detection of horizon estimation errors, due to external factors such as video transmission noise. Finally, we discuss our feed-back controller for self-stabilized flight, and report results on vision autonomous flights of duration exceeding ten minutes.

  7. Structural Sizing of a 25,000-lb Payload, Air-Breathing Launch Vehicle For Single-Stage-To-Orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.; Palac, Don (Technical Monitor)

    2000-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (5 to 10 years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  8. Structural Sizing of a 25,000-lb Payload, Air-breathing Launch Vehicle for Single-stage-to-orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.

    2001-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (five to ten years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  9. Spatially- and Temporally-Resolved Measurements of Roadway Air Pollution Using a Zero-Emission Electric Vehicle

    EPA Science Inventory

    Vehicle-related air pollution has an intrinsically dynamic nature. Recent field measurements and modeling work have demonstrated that near-road topography may modify levels of air pollutants reaching populations residing and working in close proximity to roadways. However, the ma...

  10. 77 FR 16988 - Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule for Motor Vehicle Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-23

    ...The Environmental Protection Agency (EPA) is proposing to revise one of the use conditions required for use of hydrofluoroolefin (HFO)-1234yf (2,3,3,3-tetrafluoroprop-1-ene), a substitute for ozone- depleting substances (ODSs) in the motor vehicle air conditioning end- use within the refrigeration and air conditioning sector, as acceptable subject to use conditions under the EPA's Significant......

  11. Design of an airborne launch vehicle for an air launched space booster

    NASA Technical Reports Server (NTRS)

    Chao, Chin; Choi, Rich; Cohen, Scott; Dumont, Brian; Gibin, Mauricius; Jorden, Rob; Poth, Stefan

    1993-01-01

    A conceptual design is presented for a carrier vehicle for an air launched space booster. This airplane is capable of carrying a 500,000 pound satellite launch system to an altitude over 40,000 feet for launch. The airplane features a twin fuselage configuration for improved payload and landing gear integration, a high aspect ratio wing for maneuverability at altitude, and is powered by six General Electric GE-90 engines. The analysis methods used and the systems employed in the airplane are discussed. Launch costs are expected to be competitive with existing launch systems.

  12. Operational benefits from the Terminal Configured Vehicle. [aircraft equipment for air traffic improvement

    NASA Technical Reports Server (NTRS)

    Reeder, J. P.; Schmitz, R. A.

    1978-01-01

    The objective of Terminal Configured Vehicle (TCV) research activity is to provide improvements which lead to increased airport and runway capacity, increasing air traffic controller productivity, energy efficient terminal area operations, reduced weather minima with safety, and reduced community noise by use of appropriate measures. Some early results of this research activity are discussed, and present and future research needs to meet the broad research objectives are defined. Particular consideration is given to the development of the TCV B-737 aircraft, the integration of the TCV with MLS, and avionics configurations, flight profiles, and manually controlled approaches for TCV. Some particular test demonstrations are discussed.

  13. A proposed computational technique for obtaining hypersonic air data on a sharp-nosed vehicle

    NASA Technical Reports Server (NTRS)

    Tarasidis, Jamie B.; Hellbaum, R. F.; Garner, H. Douglas

    1990-01-01

    A computational technique has been developed to obtain final air data quantities for a sharp-nosed hypersonic vehicle. Pressure measurements from five flush pressure ports are the only input needed. Four of the ports are installed around the forebody circumference and the fifth is on the nose. The pressure model is based on Lees-modified Newtonian method and corrected by pressure data from computational fluid dynamics analysis. Although this approach is similar to that used for the blunt-nosed space shuttle, it is designed specifically for a sharp-nosed aircraft. The potential of this method has been demonstrated, especially in obtaining values for dynamic pressure and angle of attack.

  14. Design of an airborne launch vehicle for an air launched space booster

    NASA Astrophysics Data System (ADS)

    Chao, Chin; Choi, Rich; Cohen, Scott; Dumont, Brian; Gibin, Mauricius; Jorden, Rob; Poth, Stefan

    1993-12-01

    A conceptual design is presented for a carrier vehicle for an air launched space booster. This airplane is capable of carrying a 500,000 pound satellite launch system to an altitude over 40,000 feet for launch. The airplane features a twin fuselage configuration for improved payload and landing gear integration, a high aspect ratio wing for maneuverability at altitude, and is powered by six General Electric GE-90 engines. The analysis methods used and the systems employed in the airplane are discussed. Launch costs are expected to be competitive with existing launch systems.

  15. Model Update of a Micro Air Vehicle (MAV) Flexible Wing Frame with Uncertainty Quantification

    NASA Technical Reports Server (NTRS)

    Reaves, Mercedes C.; Horta, Lucas G.; Waszak, Martin R.; Morgan, Benjamin G.

    2004-01-01

    This paper describes a procedure to update parameters in the finite element model of a Micro Air Vehicle (MAV) to improve displacement predictions under aerodynamics loads. Because of fabrication, materials, and geometric uncertainties, a statistical approach combined with Multidisciplinary Design Optimization (MDO) is used to modify key model parameters. Static test data collected using photogrammetry are used to correlate with model predictions. Results show significant improvements in model predictions after parameters are updated; however, computed probabilities values indicate low confidence in updated values and/or model structure errors. Lessons learned in the areas of wing design, test procedures, modeling approaches with geometric nonlinearities, and uncertainties quantification are all documented.

  16. Multi-Reflex Propulsion Systems for Space and Air Vehicles and Energy Transfer for Long Distance

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    The purpose of this article is to call attention to the revolutionary idea of light multi-reflection. This idea allows the design of new engines, space and air propulsion systems, storage (of a beam and solar energy), transmitters of energy (to millions of kilometers), creation of new weapons, etc. This method and the main innovations were offered by the author in 1983 in the former USSR. Now the author shows in a series of articles the immense possibilities of this idea in many fields of engineering - astronautics, aviation, energy, optics, direct converter of light (laser beam) energy to mechanical energy (light engine), to name a few. This article considers the multi-reflex propulsion systems for space and air vehicles and energy transmitter for long distances in space.

  17. Cushioning and lateral stability functions of cloth sport shoes.

    PubMed

    Fong, Daniel Tik-Pui; Hong, Youlian; Li, Jing Xian

    2007-09-01

    In this study, we evaluated the protective functions of cloth sport shoes, including cushioning and lateral stability. Twelve male students participated in the study (mean +/- s: age 12.7 +/- 0.4 years, mass 40.7 +/- 5.9kg, height 1.50 +/- 0.04m). Cloth sport shoes, running shoes, basketball shoes, crosstraining shoes, and barefoot conditions were investigated in random sequence. Human pendulum and cutting movement tests were used to assess cushioning performance and lateral stability, respectively. For cushioning, the running shoes (2.06 body weight, BW) performed the best, while the cross-training shoes (2.30 BW) and the basketball shoes (2.37 BW) both performed better than the cloth sport shoes (2.55 BW) and going barefoot (2.63 BW). For the lateral stability test, range of inversion--eversion was found to be from 3.6 to 4.9 degrees, which was far less than that for adult participants (> 20 degrees). No significant differences were found between conditions. All conditions showed prolonged durations from foot-strike to maximum inversion (66-95 ms), which was less vigorous than that for adult participants (< 40 ms) and was unlikely to evoke intrinsic stability failure. In conclusion, the cloth sport shoe showed inferior cushioning capability but the same lateral stability as the other sports shoes for children. PMID:17933201

  18. Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

    NASA Technical Reports Server (NTRS)

    Arnold, James O.; Deiwert, G. S.

    1997-01-01

    The dream of producing an air-breathing, hydrogen fueled, hypervelocity aircraft has been before the aerospace community for decades. However, such a craft has not yet been realized, even in an experimental form. Despite the simplicity and beauty of the concept, many formidable problems must be overcome to make this dream a reality. This paper summarizes the aero/aerothermodynamic issues that must be addressed to make the dream a reality and discusses how aerothermodynamics facilities and their modem companion, real-gas computational fluid dynamics (CFD), can help solve the problems blocking the way to realizing the dream. The approach of the paper is first to outline the concept of an air-breathing hypersonic vehicle and then discuss the nose-to-tail aerothermodynamics issues and special aerodynamic problems that arise with such a craft. Then the utility of aerothermodynamic facilities and companion CFD analysis is illustrated by reviewing results from recent United States publications wherein these problems have been addressed. Papers selected for the discussion have k e n chosen such that the review will serve to survey important U.S. aero/aerothermodynamic real gas and conventional wind tunnel facilities that are useful in the study of hypersonic, hydrogen propelled hypervelocity vehicles.

  19. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    NASA Astrophysics Data System (ADS)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz; Hussain, Abadalsalam T.

    2014-12-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  20. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    SciTech Connect

    Othman, M. N. K. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Hazry, D. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Khairunizam, Wan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Shahriman, A. B. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Yaacob, S. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  1. Neighborhood-scale air quality impacts of emissions from motor vehicles and aircraft

    NASA Astrophysics Data System (ADS)

    Choi, Wonsik; Hu, Shishan; He, Meilu; Kozawa, Kathleen; Mara, Steve; Winer, Arthur M.; Paulson, Suzanne E.

    2013-12-01

    A mobile monitoring platform (MMP) was used to measure real-time air pollutant concentrations in different built environments of Boyle Heights (BH, a lower-income community enclosed by several freeways); Downtown Los Angeles (DTLA, adjacent to BH with taller buildings and surrounded by several freeways); and West Los Angeles (WLA, an affluent community traversed by two freeways) in summer afternoons of 2008 and 2011 (only for WLA). Significant inter-community and less significant but observable intra-community differences in traffic-related pollutant concentrations were observed both in the residential neighborhoods studied and on their arterial roadways between BH, DTLA, and WLA, particularly for ultrafine particles (UFP). HEV, defined as vehicles creating plumes with concentrations more than three standard deviations from the adjusted local baseline, were encountered during 6-13% of sampling time, during which they accounted for 17-55% of total UFP concentrations both on arterial roadways and in residential neighborhoods. If instead a single threshold value is used to define HEVs in all areas, HEV's were calculated to make larger contributions to UFP concentrations in BH than other communities by factors of 2-10 or more. Santa Monica Airport located in WLA appears to be a significant source for elevated UFP concentrations in nearby residential neighborhoods 80-400 m downwind. In the WLA area, we also showed, on a neighborhood scale, striking and immediate reductions in particulate pollution (˜70% reductions in both UFP and, somewhat surprisingly, PM2.5), corresponding to dramatic decreases in traffic densities during an I-405 closure event (“Carmageddon”) compared to non-closure Saturday levels. Although pollution reduction due to decreased traffic is not unexpected, this dramatic improvement in particulate pollution provides clear evidence air quality can be improved through strategies such as heavy-duty-diesel vehicle retrofits, earlier retirement of HEV, and transition to electric vehicles and alternative fuels, with corresponding benefits for public health.

  2. Moss cushions facilitate water and nutrient supply for plant species on bare limestone pavements.

    PubMed

    Sand-Jensen, Kaj; Hammer, Kathrine Jul

    2012-10-01

    Dense moss cushions of different size are distributed across the bare limestone pavements on land, SE Sweden. Increasing cushion size is predicted to physically protect and improve performance and colonization by vascular plants. Therefore, we tested water balance, phosphorus supply, and species richness, and evaluated duration of plant activity during desiccation as a function of ground area, for a large collection of moss cushions. We found that lower evaporation and higher water storage contributed equally to extending the desiccation period with increasing cushion size. Evaporation rates declined by the -0.36 power of cushion diameter, and were not significantly different from -0.50 for the square root function previously predicted for the increasing thickness of the boundary layer, with greater linear dimensions for smooth flat objects at low wind velocities. Size dependence vanished under stagnant conditions. One moss species was added to the species pool for every nine-fold increase in cushion area. Vascular plants were absent from the smallest cushions, whereas one or two species, on average, appeared in 375- and 8,500-cm(2) cushions with water available for 6 and 10 days during desiccation. Phosphorus concentrations increased stepwise and four-fold from detritus to surface mosses and to vascular plants, and all three pools increased with cushion size. We conclude that cushion mosses and cushion size play a critical role in this resource-limited limestone environment by offering an oasis of improved water and nutrient supply to colonization and growth of plants. PMID:22481304

  3. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOEpatents

    Farrington, Robert B.; Anderson, Ren

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  4. The potential impacts of electric vehicles on air quality in the urban areas of Barcelona and Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Soret, A.; Guevara, M.; Baldasano, J. M.

    2014-12-01

    This work analyses the potential air quality improvements resulting from three fleet electrification scenarios (∼13, 26 and 40%) by replacing conventional vehicles with Electric Battery Vehicles (EBVs), Plug-in Hybrid Electric Vehicles (PHEVs) and Hybrid Electric Vehicles (HEVs). This study has been performed for the cities of Barcelona and Madrid (Spain), where road transport is the primary emission source. In these urban areas, several air quality problems are present, mainly related to NO2 and particulate matter. The WRF-ARW/HERMESv2/CMAQ model system has been applied at high spatial (1 × 1 km2) and temporal (1 h) resolution. The results show that fleet electrification offers a potential for emission abatement, especially related to NOx and CO. Regarding the more ambitious scenario (∼40% fleet electrification), reductions of 11% and 17% of the total NOx emissions are observed in Barcelona and Madrid respectively. These emissions reductions involve air quality improvements in NO2 maximum hourly values up to 16%: reductions up to 30 and 35 μg m-3 in Barcelona and Madrid, respectively. Furthermore, an additional scenario has been defined considering electric generation emissions associated with EBVs and PHEVs charging from a combined-cycle power plant. These charging emissions would produce slight NO2 increases in the downwind areas of <3 μg m-3. Thus, fleet electrification would improve urban air quality even when considering emissions associated with charging electric vehicles. However, two further points should be considered. First, fleet electrification cannot be considered a unique solution, and other management strategies may be defined. This is especially important with respect to particulate matter emissions, which are not significantly reduced by fleet electrification (<5%) due to the high weight of non-exhaust emissions. Second, a significant introduction of electric vehicles (26-40%) involving all vehicle categories is required to improve urban air quality.

  5. Mach 6.5 air induction system design for the Beta 2 two-stage-to-orbit booster vehicle

    NASA Technical Reports Server (NTRS)

    Midea, Anthony C.

    1991-01-01

    A preliminary, two-dimensional, mixed compression air induction system is designed for the Beta II Two Stage to Orbit booster vehicle to minimize installation losses and efficiently deliver the required airflow. Design concepts, such as an external isentropic compression ramp and a bypass system were developed and evaluated for performance benefits. The design was optimized by maximizing installed propulsion/vehicle system performance. The resulting system design operating characteristics and performance are presented. The air induction system design has significantly lower transonic drag than similar designs and only requires about 1/3 of the bleed extraction. In addition, the design efficiently provides the integrated system required airflow, while maintaining adequate levels of total pressure recovery. The excellent performance of this highly integrated air induction system is essential for the successful completion of the Beta II booster vehicle mission.

  6. Use of infrared and ultraviolet spectrometers to measure the effect of vehicle emissions on urban air quality

    NASA Astrophysics Data System (ADS)

    Gibbs, Dan; Betty, Christopher L.; Dolaty, Mohsen; Argento, Vittorio

    1995-05-01

    Spectroscopic techniques in the infrared and ultraviolet spectral regions may efficiently meet increasing measurement challenges in real-time detection of vehicle emissions in urban air quality studies. The results of a study are presented in which a Fourier transform infrared (FT-IR) spectrometer was used to continuously monitor motor vehicle exhaust emissions. The FT-IR identified several exhaust components, including ethylene, acetylene, propylene, isobutylene, the hydrocarbon continuum, carbon monoxide, carbon dioxide, methane, nitric oxide, and nitrous oxide. The emission of each species was shown to vary with vehicle type and the operating speed of the motor. Measurement results from this study support at least two commonly observed characteristics of motor vehicle exhaust. First, ethylene, propylene, and acetylene are common exhaust components. Ethylene was observed to be the most abundant and stable of the non-methane hydrocarbon emissions during idling for the three vehicles considered in this study. Second, the emission of NO as a function of time remains high and fairly constant at high speeds, while the concentrations of CO, HC, and the non-methane hydrocarbons decrease sharply. The results of this study strongly suggest that the FT-IR can serve as a continuous, real-time monitor for measuring motor vehicle emissions. Because it can simultaneously detect multiple pollutants and can operate in an automated fashion, the FT-IR represents a cost-effective means of determining the effect of vehicle emissions on air quality.

  7. Experimental Investigation of a Shrouded Rotor Micro Air Vehicle in Hover and in Edgewise Gusts

    NASA Astrophysics Data System (ADS)

    Hrishikeshavan, Vikram

    Due to the hover capability of rotary wing Micro Air Vehicles (MAVs), it is of interest to improve their aerodynamic performance, and hence hover endurance (or payload capability). In this research, a shrouded rotor configuration is studied and implemented, that has the potential to offer two key operational benefits: enhanced system thrust for a given input power, and improved structural rigidity and crashworthiness of an MAV platform. The main challenges involved in realising such a system for a lightweight craft are: design of a lightweight and stiff shroud, and increased sensitivity to external flow disturbances that can affect flight stability. These key aspects are addressed and studied in order to assess the capability of the shrouded rotor as a platform of choice for MAV applications. A fully functional shrouded rotor vehicle (disk loading 60 N/ m2) was designed and constructed with key shroud design variables derived from previous studies on micro shrouded rotors. The vehicle weighed about 280 g (244 mm rotor diameter). The shrouded rotor had a 30% increase in power loading in hover compared to an unshrouded rotor. Due to the stiff, lightweight shroud construction, a net payload benefit of 20-30 g was achieved. The different components such as the rotor, stabilizer bar, yaw control vanes and the shroud were systematically studied for system efficiency and overall aerodynamic improvements. Analysis of the data showed that the chosen shroud dimensions was close to optimum for a design payload of 250 g. Risk reduction prototypes were built to sequentially arrive at the final configuration. In order to prevent periodic oscillations in ight, a hingeless rotor was incorporated in the shroud. The vehicle was successfully ight tested in hover with a proportional-integralderivative feedback controller. A flybarless rotor was incorporated for efficiency and control moment improvements. Time domain system identification of the attitude dynamics of the flybar and flybarless rotor vehicle was conducted about hover. Controllability metrics were extracted based on controllability gramian treatment for the flybar and flybarless rotor. In edgewise gusts, the shrouded rotor generated up to 3 times greater pitching moment and 80% greater drag than an equivalent unshrouded rotor. In order to improve gust tolerance and control moments, rotor design optimizations were made by varying solidity, collective, operating RPM and planform. A rectangular planform rotor at a collective of 18 deg was seen to offer the highest control authority. The shrouded rotor produced 100% higher control moments due to pressure asymmetry arising from cyclic control of the rotor. It was seen that the control margin of the shrouded rotor increased as the disk loading increased, which is however deleterious in terms of hover performance. This is an important trade-off that needs to be considered. The flight performance of the vehicle in terms of edgewise gust disturbance rejection was tested in a series of bench top and free ight tests. A standard table fan and an open jet wind tunnel setup was used for bench top setup. The shrouded rotor had an edgewise gust tolerance of about 3 m/s while the unshrouded rotor could tolerate edgewise gusts greater than 5 m/s. Free flight tests on the vehicle, using VICON for position feedback control, indicated the capability of the vehicle to recover from gust impulse inputs from a pedestal fan at low gust values (up to 3 m/s).

  8. NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan

    2010-01-01

    This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

  9. Mobile Laboratory Measurements of On-Road Vehicle Air Toxics Emissions in Mexico City

    NASA Astrophysics Data System (ADS)

    Kolb, C. E.; Herndon, S. C.; Zavala, M.; Knighton, B.; Marr, L. C.; Zahniser, M. S.; Jayne, J. T.; Shorter, J. H.; Onasch, T. B.; Canagaratna, M. R.; Worsnop, D. R.; Molina, L. T.; Molina, M. J.

    2004-12-01

    The direct emission of toxic organic pollutants from mobile sources is an issue of growing concern. The U.S. Environmental Protection Agency (EPA) and the Federal Highway Administration (FHWA) have identified formaldehyde, acetaldehyde, benzene, acrolein, 1.3 butadiene, and diesel particulate matter (PM), including associated organic compounds, as mobile emissions of priority concern. Real-time trace gas and fine PM sensors deployed on the Aerodyne Research Mobile Laboratory have been used to characterize both fleet average and individual vehicle class on-road emissions of formaldehyde, acetaldehyde, benzene, and diesel particulate matter (PM), including associated organic compounds in the Mexico City Metropolitan Area (MCMA). Data for these air toxics emissions will be reviewed and compared to similar data taken in Boston and New York City, where available. The prospects for future on-road real-time monitoring of acroleinand1.3 butadiene will be discussed.

  10. Q-learning approach to automated unmanned air vehicle (UAV) demining

    NASA Astrophysics Data System (ADS)

    Ferrari, Silvia; Daugherty, Greyson

    2010-04-01

    This paper develops a Q-learning approach to Unmanned Air Vehicle (UAV) navigation, or path planning, for sensing applications in which an infrared (IR) sensor or camera is installed onboard the UAV for the purpose of detecting and classifying multiple, stationary ground targets. The problem can be considered as a geometric sensor-path planning problem, because the geometry and position of the sensor's field of view (FOV) determines what targets can be detected and classified at any given time. The advantage of this approach over existing path planning techniques is that the optimal guidance policy is learned via the Q-function, without explicit knowledge of the system models and environmental conditions. The approach is demonstrated through a demining application in which a UAV-based IR sensor is capable of determining the optimal altitude for properly detecting and classifying targets buried in a complex region of interest.

  11. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    PubMed

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies. PMID:24534328

  12. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, J. J.; Wu, L.; Mao, H. J.; Liu, H. L.; Jing, B. Y.; Yu, Y.; Ren, P. P.; Feng, C.; Liu, X. H.

    2015-07-01

    In a companion paper (Jing et al., 2015), a high temporal-spatial resolution vehicle emission inventory (HTSVE) for 2013 in Beijing has been established based on near real time (NRT) traffic data and bottom up methodology. In this study, based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modeling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing main urban areas in the periods of summer (July) and winter (December) 2013. Generally, CUACE model had good performance of pollutants concentration simulation. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes over moment. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2, while 5.4 and 10.5 % for PM2.5 in July and December 2013, respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than PM2.5 contribution rate for vehicle emission in total emission, which may be caused by easily dry deposition of PM2.5 from vehicle emission in near-surface layer compared to elevated source emission.

  13. A refuelable zinc/air battery for fleet electric vehicle propulsion

    NASA Astrophysics Data System (ADS)

    Cooper, John F.; Fleming, Dennis; Hargrove, Douglas; Koopman, Ronald; Peterman, Keith

    1995-04-01

    We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet's home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

  14. Navier-Stokes predictions of dynamic stability derivatives for air-breathing hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Liu, Wei; Zhao, Yunfei

    2016-01-01

    Dynamic derivatives are important parameters for designing vehicle trajectory and attitude control system that directly decide the divergence behavior of vibration of the aircraft open-loop system under interference. After calibration model validation, the dynamic behavior of air-breathing hypersonic vehicle WR-A is characterized. The unsteady flow field of aircraft forced simple harmonic vibration (SHV) is simulated using N-S equation. The direct damping derivatives, cross derivatives, acceleration derivatives and rotary derivatives of WR-A under different frequencies, amplitudes and positions of centroid are obtained. Research demonstrates that the proportion of acceleration derivatives, which represents the flow time lag effect, in the direct damping derivatives can be as high as 40% but is opposite to the damping derivative value symbols in some cases, contributing to dynamic instability. Numerical simulation on large-amplitude forced vibration of WR-A indicates that the aerodynamic behavior predicted by the dynamic derivative model agrees well with unsteady calculations. The inlet performance parameter derivatives are solved using the Etkin theory. The inlet performance parameters under large-amplitude vibration are successfully predicted using the dynamic derivative model. This offers a guideline for characterizing the dynamic internal flow field and unsteady inlet performance.

  15. Aerodynamics of a bio-inspired flexible flapping-wing micro air vehicle.

    PubMed

    Nakata, T; Liu, H; Tanaka, Y; Nishihashi, N; Wang, X; Sato, A

    2011-12-01

    MAVs (micro air vehicles) with a maximal dimension of 15 cm and nominal flight speeds of around 10 m s?, operate in a Reynolds number regime of 10? or lower, in which most natural flyers including insects, bats and birds fly. Furthermore, due to their light weight and low flight speed, the MAVs' flight characteristics are substantially affected by environmental factors such as wind gust. Like natural flyers, the wing structures of MAVs are often flexible and tend to deform during flight. Consequently, the aero/fluid and structural dynamics of these flyers are closely linked to each other, making the entire flight vehicle difficult to analyze. We have recently developed a hummingbird-inspired, flapping flexible wing MAV with a weight of 2.4-3.0 g and a wingspan of 10-12 cm. In this study, we carry out an integrated study of the flexible wing aerodynamics of this flapping MAV by combining an in-house computational fluid dynamic (CFD) method and wind tunnel experiments. A CFD model that has a realistic wing planform and can mimic realistic flexible wing kinematics is established, which provides a quantitative prediction of unsteady aerodynamics of the four-winged MAV in terms of vortex and wake structures and their relationship with aerodynamic force generation. Wind tunnel experiments further confirm the effectiveness of the clap and fling mechanism employed in this bio-inspired MAV as well as the importance of the wing flexibility in designing small flapping-wing MAVs. PMID:22126793

  16. Uncertainty analysis and robust trajectory linearization control of a flexible air-breathing hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Pu, Zhiqiang; Tan, Xiangmin; Fan, Guoliang; Yi, Jianqiang

    2014-08-01

    Flexible air-breathing hypersonic vehicles feature significant uncertainties which pose huge challenges to robust controller designs. In this paper, four major categories of uncertainties are analyzed, that is, uncertainties associated with flexible effects, aerodynamic parameter variations, external environmental disturbances, and control-oriented modeling errors. A uniform nonlinear uncertainty model is explored for the first three uncertainties which lumps all uncertainties together and consequently is beneficial for controller synthesis. The fourth uncertainty is additionally considered in stability analysis. Based on these analyses, the starting point of the control design is to decompose the vehicle dynamics into five functional subsystems. Then a robust trajectory linearization control (TLC) scheme consisting of five robust subsystem controllers is proposed. In each subsystem controller, TLC is combined with the extended state observer (ESO) technique for uncertainty compensation. The stability of the overall closed-loop system with the four aforementioned uncertainties and additional singular perturbations is analyzed. Particularly, the stability of nonlinear ESO is also discussed from a Linard system perspective. At last, simulations demonstrate the great control performance and the uncertainty rejection ability of the robust scheme.

  17. A refuelable zinc/air battery for fleet electric vehicle propulsion

    SciTech Connect

    Cooper, J.F.; Fleming, D.; Hargrove, D.; Koopman, R.; Peterman, K.

    1995-04-20

    We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet s home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

  18. Preliminary development of a VTOL unmanned air vehicle for the close-range mission

    NASA Astrophysics Data System (ADS)

    Kress, Gregory A.

    1992-09-01

    The preliminary development of a full-scale Vertical Takeoff and Landing (VTOL) Unmanned Air Vehicle (UAV) for the Close-Range mission was completed at the Naval Postgraduate School (NPS). The vehicle was based on half-scale ducted-fan investigations performed at the UAV Flight Research Lab. The resulting design is a fixed-duct, tail-sitter UAV with a canard-configured horizontal stabilizer. Major airframe components are used from previous UAV's and include the wings from a U.S. Army Aquila and the ducted fan from the U.S. Marine Corps AROD. Accomplishments include: (1) the design and fabrication of a carry-through spar, and (2) the design and construction of an engine test stand. The through spar was designed using finite element analysis and constructed from composite materials. The purpose of the test stand is to measure torque, horsepower, and thrust of an entire ducted fan or an individual engine. Completion of this thesis will pave the way for future NPS research into the growing interest in VTOL UAV technology.

  19. The development of an experimental facility and investigation of rapidly maneuvering Micro-Air-Vehicle wings

    NASA Astrophysics Data System (ADS)

    Wilson, Lee Alexander

    Vertical Takeoff-and-Landing (VTOL) Micro Air Vehicles (MAVs) provide a versatile operational platform which combines the capabilities of fixed wing and rotary wing MAVs. In order to improve performance of these vehicles, a better understanding of the rapid transition between horizontal and vertical flight is required. This study examines the flow structures around the Mini-Vertigo VTOL MAV using flow visualization techniques. This will gives an understanding of the flow structures which dominate the flight dynamics of rapid pitching maneuvers. This study consists of three objectives: develop an experimental facility, use flow visualization to investigate the flow around the experimental subject during pitching, and analyze the results. The flow around the Mini-Vertigo VTOL MAV is dominated by the slipstream from its propellers. The slipstream delays LE separation and causes drastic deflection in the flow. While the frequency of the vortices shed from the LE and TE varies with flow speed, the non-dimensional frequency does not. It does, however, vary slightly with the pitching rate. These results are applicable across a wide range of flight conditions. The results correlate to previous research done to examine the aerodynamic forces on the MAV.

  20. The development of aluminum-air batteries for application in electric vehicles

    NASA Astrophysics Data System (ADS)

    Rudd, E. J.; Lott, S.

    1990-12-01

    The recently concluded program, jointly funded by ELTECH Research Corporation and the Department of Energy, focused upon the development of an aluminum-air battery system for electric vehicle applications. The operation of the aluminum-air battery involves the dissolution of aluminum to produce a current and aluminate. Initially the objectives were to evaluate and optimize the battery design that was developed prior to this program (designated as the B300 cell) and to design and evaluate the components of the auxiliary system. During the program, three additional tasks were undertaken, addressing needs identified by ELTECH and by Sandia National Laboratories. First, the capability to produce aluminum alloys as relatively large ingots (100 to 150 lbs), with the required electrochemical performance, was considered essential to the development of the battery. The second additional task was the adoption of an advanced cell (designated as the AT400 cell), designed by ELTECH in a different program. Finally, it was recognized that a system model would allow evaluation of the interactions of the several unit operations involved in the battery. Therefore, the development of a mathematical model, based upon material and energy balances for the battery, was undertaken. At a systems level, sufficient information was obtained in the completion of this program to support the design, fabrication and operation of a batch or solids-free battery system. For the first time, the components of the auxiliary system, i.e., a heat exchanger, carbon dioxide scrubber and hydrogen disposal technology, have been defined for a vehicle battery. Progress on each component or system is summarized in the following sections.

  1. Optimization of aircraft seat cushion fire blocking layers

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.; Ling, A. C.; Hovatter, W. R.

    1983-01-01

    This report describes work completed by the National Aeronautics and Space Administration - for the Federal Aviation Administration Technical Center. The purpose of this work was to examine the potential of fire blocking mechanisms for aircraft seat cushions in order to provide an optimized seat configuration with adequate fire protection and minimum weight. Aluminized thermally stable fabrics were found to provide adequate fire protection when used in conjunction with urethane foams, while maintaining minimum weight and cost penalty.

  2. Estimation of road vehicle exhaust emissions from 1992 to 2010 and comparison with air quality measurements in Genoa, Italy

    NASA Astrophysics Data System (ADS)

    Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

    An investigation into road transport exhaust emissions in the Genoa urban area was performed by comparing the quantities of carbon monoxide (CO), nitrogen oxides (NO x), nitrogen dioxide (NO 2) and particulate matter (PM) emitted by different vehicle categories with air quality measurements referred to the same pollutants. Exhaust emissions were evaluated by applying the PROGRESS (computer PROGramme for Road vehicle EmiSSions evaluation) code, developed by the Internal Combustion Engines Group of the University of Genoa, to eight different years (from 1992 to 2010), considering spark ignition and Diesel passenger cars and light duty vehicles, heavy duty vehicles and buses, motorcycles and mopeds. Changes in terms of vehicles number, mileage and total emissions are presented together with relative distributions among the various vehicle categories. By comparing 1992 and 2010 data, calculated trends show a 7% increase in the number of vehicles, with total mileage growing at a faster rate (approx. 22%); total emissions decrease considerably, by approximately 50% for NO x and PM, 70% for HC and 80% for CO, due to improvements in engines and fuels forced by the stricter European legislation and the fleet renewal, while primary NO 2 emission will be very close to 1992 level, after a decrease of about 18% in 2000. Air quality was analysed by selecting traffic and background measuring stations from the monitoring network managed by the Environmental Department of the Province of Genoa: average annual concentrations of considered pollutants from 1994 to 2007 were calculated in order to obtain the relative historical trends and compare them with European public health limits and with road vehicle emissions. Though an important reduction in pollutant concentrations has been achieved as a consequence of cleaner vehicles, some difficulties in complying with present and/or future NO 2 and PM 10 limits are also apparent, thus requiring suitable measures to be taken by the local authorities.

  3. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, Jianjun; Wu, Lin; Mao, Hongjun; Liu, Hongli; Jing, Boyu; Yu, Ye; Ren, Peipei; Feng, Cheng; Liu, Xuehao

    2016-03-01

    A companion paper developed a vehicle emission inventory with high temporal-spatial resolution (HTSVE) with a bottom-up methodology based on local emission factors, complemented with the widely used emission factors of COPERT model and near-real-time (NRT) traffic data on a specific road segment for 2013 in urban Beijing (Jing et al., 2016), which is used to investigate the impact of vehicle pollution on air pollution in this study. Based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modelling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing's main urban areas in the periods of summer (July) and winter (December) 2013. Generally, the CUACE model had good performance of the concentration simulation of pollutants. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes with time. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2 and 5.4 and 10.5 % for PM2.5 in July and December 2013 respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while it is 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than the PM2.5 contribution rate for vehicle emission in total emission, which may be due to dry deposition of PM2.5 from vehicle emission in the near-surface layer occuring more easily than from elevated source emission.

  4. Networking Multiple Autonomous Air and Ocean Vehicles for Oceanographic Research and Monitoring

    NASA Astrophysics Data System (ADS)

    McGillivary, P. A.; Borges de Sousa, J.; Rajan, K.

    2013-12-01

    Autonomous underwater and surface vessels (AUVs and ASVs) are coming into wider use as components of oceanographic research, including ocean observing systems. Unmanned airborne vehicles (UAVs) are now available at modest cost, allowing multiple UAVs to be deployed with multiple AUVs and ASVs. For optimal use good communication and coordination among vehicles is essential. We report on the use of multiple AUVs networked in communication with multiple UAVs. The UAVs are augmented by inferential reasoning software developed at MBARI that allows UAVs to recognize oceanographic fronts and change their navigation and control. This in turn allows UAVs to automatically to map frontal features, as well as to direct AUVs and ASVs to proceed to such features and conduct sampling via onboard sensors to provide validation for airborne mapping. ASVs can also act as data nodes for communication between UAVs and AUVs, as well as collecting data from onboard sensors, while AUVs can sample the water column vertically. This allows more accurate estimation of phytoplankton biomass and productivity, and can be used in conjunction with UAV sampling to determine air-sea flux of gases (e.g. CO2, CH4, DMS) affecting carbon budgets and atmospheric composition. In particular we describe tests in July 2013 conducted off Sesimbra, Portugal in conjunction with the Portuguese Navy by the University of Porto and MBARI with the goal of tracking large fish in the upper water column with coordinated air/surface/underwater measurements. A thermal gradient was observed in the infrared by a low flying UAV, which was used to dispatch an AUV to obtain ground truth to demonstrate the event-response capabilities using such autonomous platforms. Additional field studies in the future will facilitate integration of multiple unmanned systems into research vessel operations. The strength of hardware and software tools described in this study is to permit fundamental oceanographic measurements of both ocean and atmosphere over temporal and spatial scales that have previously been problematic. The methods demonstrated are particularly suited to the study of oceanographic fronts and for tracking and mapping oil spills or plankton blooms. With the networked coordination of multiple autonomous systems, individual components may be changed out while ocean observations continue, allowing coarse to fine spatial studies of hydrographic features over temporal dimensions that would otherwise be difficult, including diurnal and tidal periods. Constraints on these methods currently involve coordination of data archiving systems into shipboard operating systems, familiarization of oceanographers with these methods, and existing nearshore airspace use constraints on UAVs. An important outcome of these efforts is to understand the methodology for using multiple heterogeneous autonomous vehicles for targeted science exploration.

  5. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    PubMed

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. PMID:25825338

  6. Effects of heated seats in vehicles on thermal comfort during the initial warm-up period.

    PubMed

    Oi, Hajime; Tabata, Koji; Naka, Yasuhito; Takeda, Akira; Tochihara, Yutaka

    2012-03-01

    Eight subjects participated in a subjective experiment of eight conditions to investigate the effects of heated seats in vehicles on skin temperature, thermal sensation and thermal comfort during the initial warm-up period. The experimental conditions were designed as a combination of air temperature in the test room (5, 10, 15, or 20 C) and heated seat (on/off). The heated seat was effective for improving thermal comfort during the initial warm-up period when air temperature was lower than 15 C. Use of heated seats prevented decreases in or increased toe skin temperature. Heated seats also increased foot thermal sensation at 15 and 20 C. Optimal thermal sensation in contact with the seat was higher when air temperature was lower. Optimal skin temperature in contact with the seat back was higher than that with the seat cushion. Moreover, these optimal skin temperatures were higher when air temperature was lower. PMID:21683338

  7. Design and fabrication of microflap actuators for steering of micro air vehicles

    NASA Astrophysics Data System (ADS)

    Zimbru, George C.; Lee, Woo Ho; Popa, Dan O.

    2009-05-01

    This paper presents the design, analysis, and fabrication of an array of microflap actuators that can produce a substantial aerodynamic force for course corrections of Micro Air Vehicles (MAVs) and low speed projectiles. In the past, several actuation principles, including microjet, magnetic and bubble actuators, and flapping wings have been proposed, and had varying degrees of success. In this paper, we discuss the benefits and drawbacks of past attempts, and the technology that can be used to address the microflap steering problem. We propose a hybrid microflap actuation scheme that combines two types of actuators including: 1) a MEMS fabricated "active" microactuator connected to a microflap, and 2) a "passive" fluidic channel system that harvests the potential energy in the high pressure field on the leading edge of the MAV or high speed projectile to achieve a desired deflection. An array of microflap actuators was prototyped using silicon MEMS fabrication and microassembly. A Silicon On Insulator (SOI) wafer with 100 micron thick device layer was used to as a substrate material to fabricate microflap structures with springs. Front and back side DRIE process was used to etch and release the microstructures including microflaps. Then, the microactuator was assembled on top of the microflap. The static and dynamic behaviors of a microflap were measured using a laser displacement sensor and were compared to the analytic model. In the near future, a prototyped microflap will be tested inside of a wind tunnel to measure the lift and drag at various air speeds.

  8. Australian Air Breathing Propulsion Research for Hypersonic, Beamed Energy-Propelled Vehicles

    NASA Astrophysics Data System (ADS)

    Froning, David

    2010-05-01

    A three year laser-propelled vehicle analysis and design investigation has been begun in June, 2009 by Faculty and graduate students at the University of Adelaide under a Grant/Cooperative Agreement Award to the University of Adelaide by the Asian Office of Aerospace Research and Development (AOARD). The major objectives of thsis investigation are: (a) development of hypersonic, air breathing "lightcraft" with innovative air inlets that enable acceptable airflow capture and combustion, and acceptable cowl-lip heating rates during hot, high-speed, high angle-of-attack hypersonic flight; (b) yest of the most promising lightcraft and inlet design in the high power laser beam that is part of the shock tunnel facility at CTO Instituto in Brazil; and (c) plan a series of laser guided and propelled flights that achieve supersonic or higher speed at the Woomera Test Facility (WTF) in South Australiausing the existing WTF launching and tracking facilities and sponsor-provided laser pointing and tracking and illumination systems.

  9. Short communication: Genetic characterization of digital cushion thickness.

    PubMed

    Oikonomou, G; Banos, G; Machado, V; Caixeta, L; Bicalho, R C

    2014-01-01

    Dairy cow lameness is a serious animal welfare issue. It is also a significant cause of economic losses, reducing reproductive efficiency and milk production and increasing culling rates. The digital cushion is a complex structure composed mostly of adipose tissue located underneath the distal phalanx and has recently been phenotypically associated with incidence of claw horn disruption lesions (CHDL); namely, sole ulcers and white line disease. The objective of this study was to characterize digital cushion thickness genetically and to investigate its association with body condition score (BCS), locomotion score (LOCO), CHDL, and milk production. Data were collected from 1 large closely monitored commercial dairy farm located in upstate New York; 923 dairy cows were used. Before trimming, the following data were collected by a member of the research team: BCS, cow height measurement, and LOCO. Presence or not of CHDL (sole ulcer or white line disease, or both) was recorded at trimming. Immediately after the cows were hoof trimmed, they underwent digital sonographic B-mode examination for the measurement of digital cushion thickness. Factors such as parity number, stage of lactation, calving date, mature-equivalent 305-d milk yield (ME305MY), and pedigree information were obtained from the farm's dairy management software (DairyCOMP 305; Valley Agricultural Software, Tulare, CA). Univariate animal models were used to obtain variance component estimations for each studied trait (CHDL, BCS, digital cushion thickness average, LOCO, height, and ME305MY) and a 6-variate analysis was conducted to estimate the genetic, residual, and phenotypic correlations between the studied traits. The heritability estimate of DCTA was 0.33±0.09, whereas a statistically significant genetic correlation was estimated between DCTA and CHDL (-0.60±0.29). Of the other genetic correlations, significant estimates were derived for BCS with LOCO (-0.49±0.19) and ME305MY (-0.48±0.20). Digital cushion thickness is moderately heritable and genetically strongly correlated with CHDL. PMID:24239082

  10. The impact of China's vehicle emissions on regional air quality in 2000 and 2020: a scenario analysis

    NASA Astrophysics Data System (ADS)

    Saikawa, E.; Kurokawa, J.; Takigawa, M.; Mauzerall, D. L.; Horowitz, L. W.; Ohara, T.

    2011-04-01

    The number of vehicles in China has been increasing rapidly. We evaluate the impact of current and possible future vehicle emissions from China on Asian air quality. We modify the Regional Emission Inventory in Asia (REAS) for China's road transport sector in 2000 using updated Chinese data for vehicle numbers, annual mileage and emission factors. We develop two scenarios for 2020: a scenario where emission factors remain the same as they were before any regulation was implemented (business-as-usual, BAU), and a scenario where Euro 3 vehicle emission standards are applied to all vehicles (except motorcycles and rural vehicles). The Euro 3 scenario is an approximation of what may be the case in 2020 as, starting in 2008, all new gasoline and diesel vehicles in China (except motorcycles) were required to meet the Euro 3 emission standards. Using the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem), we examine the regional air quality response to China's vehicle emissions in 2000 and in 2020 for the BAU and Euro 3 scenarios. We evaluate the 2000 model results with observations in Japan, China, Korea, and Russia. Under BAU in 2020, emissions of carbon monoxide (CO), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), black carbon (BC) and organic carbon (OC) from China's vehicles more than double compared to the 2000 baseline. If all vehicles meet the Euro 3 regulations in 2020, however, these emissions are reduced by more than 50% relative to BAU. The implementation of stringent vehicle emission standards leads to a large, simultaneous reduction of the surface ozone (O3) mixing ratios and particulate matter (PM2.5) concentrations. In the Euro 3 scenario, surface O3 is reduced by more than 10 ppbv and surface PM2.5 is reduced by more than 10 μg m-3 relative to BAU in Northeast China in all seasons. In spring, surface O3 mixing ratios and PM2.5 concentrations in neighboring countries are also reduced by more than 3 ppbv and 1 μg m-3, respectively. We find that effective regulation of China's road transport sector will be of significant benefit for air quality both within China and across East Asia as well.

  11. The impact of China's vehicle emissions on regional air quality in 2000 and 2020: a scenario analysis

    NASA Astrophysics Data System (ADS)

    Saikawa, E.; Kurokawa, J.; Takigawa, M.; Borken-Kleefeld, J.; Mauzerall, D. L.; Horowitz, L. W.; Ohara, T.

    2011-09-01

    The number of vehicles in China has been increasing rapidly. We evaluate the impact of current and possible future vehicle emissions from China on Asian air quality. We modify the Regional Emission Inventory in Asia (REAS) for China's road transport sector in 2000 using updated Chinese data for the number of vehicles, annual mileage, and emission factors. We develop two scenarios for 2020: a scenario where emission factors remain the same as they were in 2000 (No-Policy, NoPol), and a scenario where Euro 3 vehicle emission standards are applied to all vehicles (except motorcycles and rural vehicles). The Euro 3 scenario is an approximation of what may be the case in 2020 as, starting in 2008, all new vehicles in China (except motorcycles) were required to meet the Euro 3 emission standards. Using the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem), we examine the regional air quality response to China's vehicle emissions in 2000 and in 2020 for the NoPol and Euro 3 scenarios. We evaluate the 2000 model results with observations in Japan, China, Korea, and Russia. Under NoPol in 2020, emissions of carbon monoxide (CO), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), black carbon (BC), and organic carbon (OC) from China's vehicles more than double compared to the 2000 baseline. If all vehicles meet the Euro 3 regulations in 2020, however, these emissions are reduced by more than 50% relative to NoPol. The implementation of stringent vehicle emission standards leads to a large, simultaneous reduction of the surface ozone (O3) mixing ratios and particulate matter (PM2.5) concentrations. In the Euro 3 scenario, surface O3 is reduced by more than 10 ppbv and surface PM2.5 is reduced by more than 10 μg m-3 relative to NoPol in Northeast China in all seasons. In spring, surface O3 mixing ratios and PM2.5 concentrations in neighboring countries are also reduced by more than 3 ppbv and 1 μg m-3, respectively. We find that effective regulation of China's road transport sector will be of significant benefit for air quality both within China and across East Asia as well.

  12. Control and design of multiple unmanned air vehicles for persistent surveillance

    NASA Astrophysics Data System (ADS)

    Nigam, Nikhil

    Control of multiple autonomous aircraft for search and exploration, is a topic of current research interest for applications such as weather monitoring, geographical surveys, search and rescue, tactical reconnaissance, and extra-terrestrial exploration, and the need to distribute sensing is driven by considerations of efficiency, reliability, cost and scalability. Hence, this problem has been extensively studied in the fields of controls and artificial intelligence. The task of persistent surveillance is different from a coverage/exploration problem, in that all areas need to be continuously searched, minimizing the time between visitations to each region in the target space. This distinction does not allow a straightforward application of most exploration techniques to the problem, although ideas from these methods can still be used. The use of aerial vehicles is motivated by their ability to cover larger spaces and their relative insensitivity to terrain. However, the dynamics of Unmanned Air Vehicles (UAVs) adds complexity to the control problem. Most of the work in the literature decouples the vehicle dynamics and control policies, but their interaction is particularly interesting for a surveillance mission. Stochastic environments and UAV failures further enrich the problem by requiring the control policies to be robust, and this aspect is particularly important for hardware implementations. For a persistent mission, it becomes imperative to consider the range/endurance constraints of the vehicles. The coupling of the control policy with the endurance constraints of the vehicles is an aspect that has not been sufficiently explored. Design of UAVs for desirable mission performance is also an issue of considerable significance. The use of a single monolithic optimization for such a problem has practical limitations, and decomposition-based design is a potential alternative. In this research high-level control policies are devised, that are scalable, reliable, efficient, and robust to changes in the environment. Most of the existing techniques that carry performance guarantees are not scalable or robust to changes. The scalable techniques are often heuristic in nature, resulting in lack of reliability and performance. Our policies are tested in a multi-UAV simulation environment developed for this problem, and shown to be near-optimal in spite of being completely reactive in nature. We explicitly account for the coupling between aircraft dynamics and control policies as well, and suggest modifications to improve performance under dynamic constraints. A smart refueling policy is also developed to account for limited endurance, and large performance benefits are observed. The method is based on the solution of a linear program that can be efficiently solved online in a distributed setting, unlike previous work. The Vehicle Swarm Technology Laboratory (VSTL), a hardware testbed developed at Boeing Research and Technology for evaluating swarm of UAVs, is described next and used to test the control strategy in a real-world scenario. The simplicity and robustness of the strategy allows easy implementation and near replication of the performance observed in simulation. Finally, an architecture for system-of-systems design based on Collaborative Optimization (CO) is presented. Earlier work coupling operations and design has used frameworks that make certain assumptions not valid for this problem. The efficacy of our approach is illustrated through preliminary design results, and extension to more realistic settings is also demonstrated.

  13. Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine

    SciTech Connect

    Ng, H.K.; Sekar, R.R.

    1994-04-01

    A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO{sub x} emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO{sub x} emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO{sub x} emissions could meet the 2004 Tier II emissions standards with 25%-oxygen-content air.

  14. The structure of the cushions in the feet of African elephants (Loxodonta africana)

    PubMed Central

    Weissengruber, G E; Egger, G F; Hutchinson, J R; Groenewald, H B; Elssser, L; Famini, D; Forstenpointner, G

    2006-01-01

    The uniquely designed limbs of the African elephant, Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. VaterPacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures. PMID:17118065

  15. Integration of Advanced Concepts and Vehicles Into the Next Generation Air Transportation System. Volume 1; Introduction, Key Messages, and Vehicle Attributes

    NASA Technical Reports Server (NTRS)

    Zellweger, Andres; Resnick, Herbert; Stevens, Edward; Arkind, Kenneth; Cotton William B.

    2010-01-01

    Raytheon, in partnership with NASA, is leading the way in ensuring that the future air transportation continues to be a key driver of economic growth and stability and that this system provides an environmentally friendly, safe, and effective means of moving people and goods. A Raytheon-led team of industry and academic experts, under NASA contract NNA08BA47C, looked at the potential issues and impact of introducing four new classes of advanced aircraft into the next generation air transportation system -- known as NextGen. The study will help determine where NASA should further invest in research to support the safe introduction of these new air vehicles. Small uncrewed or unmanned aerial systems (SUAS), super heavy transports (SHT) including hybrid wing body versions (HWB), very light jets (VLJ), and supersonic business jets (SSBJ) are the four classes of aircraft that we studied. Understanding each vehicle's business purpose and strategy is critical to assessing the feasibility of new aircraft operations and their impact on NextGen's architecture. The Raytheon team used scenarios created by aviation experts that depict vehicles in year 2025 operations along with scripts or use cases to understand the issues presented by these new types of vehicles. The information was then mapped into the Joint Planning and Development Office's (JPDO s) Enterprise Architecture to show how the vehicles will fit into NextGen's Concept of Operations. The team also identified significant changes to the JPDO's Integrated Work Plan (IWP) to optimize the NextGen vision for these vehicles. Using a proven enterprise architecture approach and the JPDO s Joint Planning Environment (JPE) web site helped make the leap from architecture to planning efficient, manageable and achievable. Very Light Jets flying into busy hub airports -- Supersonic Business Jets needing to climb and descend rapidly to achieve the necessary altitude Super-heavy cargo planes requiring the shortest common flight path -- are just a few of the potential new operations in the future National Airspace System. To assess the impact of these new scenarios on overall national airspace operations, the Raytheon team used the capabilities of a suite of tools such as NASA's Airspace Concepts Evaluation System (ACES), the Flight Optimization System (FLOPS), FAA's Aviation Environmental Design Tool (AEDT), Intelligent Automations Kinematic Trajectory Generator (KTG) and the Aviation Safety Risk Model (ASRM). Detailed metroplex modeling, surface delay models for super heavy transports, prioritized routing and corridors for supersonics business jets, and VLJ demand models are some of the models developed by the Raytheon team to study the effect of operating these new vehicles in the future NAS. Using this suite of models, several trade studies were conducted to evaluate these effects in terms of delays, equity in access, safety, and the environment. Looking at the impact of each vehicle, a number of critical issues were identified. The Raytheon team concluded that strict compliance to NextGen's 4-dimensional trajectory (4DT) management will be required to accommodate these vehicles unique operations and increased number of flights in the future air space system. The next section provides a discussion of this and the other key findings from our study.

  16. Micro-electro-mechanical flapping wing technology for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Hall, Asha J.; Riddick, Jaret C.

    2012-04-01

    Army combat operations have placed a high premium on reconnaissance missions for Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs) (less than 15 cm in dimension and less than 20 g in mass). One approach for accomplishing this mission is to develop a biologically inspired flapping wing insect that can maneuver into confined areas and possess hovering capabilities. Analysis of insect flight indicates that in addition to the bending excitation (flapping), simultaneous excitation of the twisting degree-of-freedom (pitching) is required to manipulate the control surface adequately. Traditionally, bimorph piezoelectric PZT (Pb(Zr0.55Ti0.45)O3) actuators have been used in many applications to excite the bending degree-of-freedom. In laminated or layered structures, bend-twist coupling is governed by the existence of at least one anisotropic layer not aligned with the primary plate axes. By adding a layer of off-axis PZT segments to a PZT bimorph actuator, thereby producing a layered structure to be referred to as a functionally- modified bimorph, bend-twist coupling may be introduced to the flexural response of the layered PZT. Furthermore, by selectively charging off-axis layers in specific combinations with the bimorph, the response of the functionally-modified bimorph may be tailored yielding a biaxial actuator to actively control the flapping wing response. The present study presents an experimental investigation of both traditional bimorph and functionally-modified PZT bimorph designs intended for active bend-twist actuation of cm-scale flapping wing devices.

  17. Autonomous Landing and Ingress of Micro-Air-Vehicles in Urban Environments Based on Monocular Vision

    NASA Technical Reports Server (NTRS)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-01-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  18. Autonomous landing and ingress of micro-air-vehicles in urban environments based on monocular vision

    NASA Astrophysics Data System (ADS)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-06-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  19. Fully self-contained vision-aided navigation and landing of a micro air vehicle independent from external sensor inputs

    NASA Astrophysics Data System (ADS)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-06-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  20. Fully Self-Contained Vision-Aided Navigation and Landing of a Micro Air Vehicle Independent from External Sensor Inputs

    NASA Technical Reports Server (NTRS)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-01-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  1. Measurement of Fine Particles From Mobile and Stationary Sources, and Reducing the Air Conditioner Power Consumption in Hybrid Electric Vehicles

    NASA Astrophysics Data System (ADS)

    Brewer, Eli Henry

    We study the PM2.5and ultrafine exhaust emissions from a new natural gas-fired turbine power facility to better understand air pollution in California. To characterize the emissions from new natural gas turbines, a series of tests were performed on a GE LMS100 gas turbine. These tests included PM2.5 and wet chemical tests for SO2/SO 3 and NH3, as well as ultrafine (less than 100 nm in diameter) particulate matter measurements. The turbine exhaust had an average particle number concentration that was 2.3x103 times higher than ambient air. The majority of these particles were nanoparticles; at the 100 nm size, stack particle concentrations were about 20 times higher than ambient, and increased to 3.9x104 times higher on average in the 2.5 - 3 nm particle size range. This study also found that ammonia emissions were higher than expected, but in compliance with permit conditions. This was possibly due to an ammonia imbalance entering the catalyst, some flue gas bypassing the catalyst, or not enough catalyst volume. SO3 accounted for an average of 23% of the total sulfur oxides emissions measured. Some of the SO3 is formed in the combustion process, it is likely that the majority formed as the SO2 in the combustion products passed across the oxidizing CO catalyst and SCR catalyst. The 100 MW turbine sampled in this study emitted particle loadings similar to those previously measured from turbines in the SCAQMD area, however, the turbine exhaust contained far more particles than ambient air. The power consumed by an air conditioner accounts for a significant fraction of the total power used by hybrid and electric vehicles especially during summer. This study examined the effect of recirculation of cabin air on power consumption of mobile air conditioners both in-lab and on-road. Real time power consumption and vehicle mileage were recorded by an On Board Diagnostic monitor and carbon balance method. Vehicle mileage improved with increased cabin air recirculation. The recirculation of cabin air also significantly reduced in-cabin particle concentrations. Recirculation of cabin air is an excellent and immediate solution to increase vehicle mileage and improve cabin air quality.

  2. Conservation equations and physical models for hypersonic air flows over the aeroassist flight experiment vehicle

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.

    1989-01-01

    The code development and application program for the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), with emphasis directed toward support of the Aeroassist Flight Experiment (AFE) in the near term and Aeroassisted Space Transfer Vehicle (ASTV) design in the long term is reviewed. LAURA is an upwind-biased, point-implicit relaxation algorithm for obtaining the numerical solution to the governing equations for 3-D, viscous, hypersonic flows in chemical and thermal nonequilibrium. The algorithm is derived using a finite volume formulation in which the inviscid components of flux across cell walls are described with Roe's averaging and Harten's entropy fix with second-order corrections based on Yee's Symmetric Total Variation Diminishing scheme. Because of the point-implicit relaxation strategy, the algorithm remains stable at large Courant numbers without the necessity of solving large, block tri-diagonal systems. A single relaxation step depends only on information from nearest neighbors. Predictions for pressure distributions, surface heating, and aerodynamic coefficients compare well with experimental data for Mach 10 flow over an AFE wind tunnel model. Predictions for the hypersonic flow of air in chemical and thermal nonequilibrium over the full scale AFE configuration obtained on a multi-domain grid are discussed.

  3. Low Dimensional Tools for Flow-Structure Interaction Problems: Application to Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Schmit, Ryan F.; Glauser, Mark N.; Gorton, Susan A.

    2003-01-01

    A low dimensional tool for flow-structure interaction problems based on Proper Orthogonal Decomposition (POD) and modified Linear Stochastic Estimation (mLSE) has been proposed and was applied to a Micro Air Vehicle (MAV) wing. The method utilizes the dynamic strain measurements from the wing to estimate the POD expansion coefficients from which an estimation of the velocity in the wake can be obtained. For this experiment the MAV wing was set at five different angles of attack, from 0 deg to 20 deg. The tunnel velocities varied from 44 to 58 ft/sec with corresponding Reynolds numbers of 46,000 to 70,000. A stereo Particle Image Velocimetry (PIV) system was used to measure the wake of the MAV wing simultaneously with the signals from the twelve dynamic strain gauges mounted on the wing. With 20 out of 2400 POD modes, a reasonable estimation of the flow flow was observed. By increasing the number of POD modes, a better estimation of the flow field will occur. Utilizing the simultaneously sampled strain gauges and flow field measurements in conjunction with mLSE, an estimation of the flow field with lower energy modes is reasonable. With these results, the methodology for estimating the wake flow field from just dynamic strain gauges is validated.

  4. Multi-terminal remote monitoring and warning system using Micro Air Vehicle for dangerous environment

    NASA Astrophysics Data System (ADS)

    Yu, Yanan; Wang, Xiaoxun; He, Chengcheng; Lai, Chenlong; Liu, Yuanchao

    2015-11-01

    For overcoming the problems such as remote operation and dangerous tasks, multi-terminal remote monitoring and warning system based on STC89C52 Micro Control Unit and wireless communication technique was proposed. The system with MCU as its core adopted multiple sets of sensor device to monitor environment parameters of different locations, such as temperature, humidity, smoke other harmful gas concentration. Data information collected was transmitted remotely by wireless transceiver module, and then multi-channel data parameter was processed and displayed through serial communication protocol between the module and PC. The results of system could be checked in the form of web pages within a local network which plays a wireless monitoring and warning role. In a remote operation, four-rotor micro air vehicle which fixed airborne data acquisition device was utilized as a middleware between collecting terminal and PC to increase monitoring scope. Whole test system has characteristics of simple construction, convenience, real time ability and high reliability, which could meet the requirements of actual use.

  5. The novel aerodynamics of insect flight: applications to micro-air vehicles.

    PubMed

    Ellington, C P

    1999-12-01

    The wing motion in free flight has been described for insects ranging from 1 to 100 mm in wingspan. To support the body weight, the wings typically produce 2-3 times more lift than can be accounted for by conventional aerodynamics. Some insects use the fling mechanism: the wings are clapped together and then flung open before the start of the downstroke, creating a lift-enhancing vortex around each wing. Most insects, however, rely on a leading-edge vortex (LEV) created by dynamic stall during flapping; a strong spanwise flow is also generated by the pressure gradients on the flapping wing, causing the LEV to spiral out to the wingtip. Technical applications of the fling are limited by the mechanical damage that accompanies repeated clapping of the wings, but the spiral LEV can be used to augment the lift production of propellers, rotors and micro-air vehicles (MAVs). Design characteristics of insect-based flying machines are presented, along with estimates of the mass supported, the mechanical power requirement and maximum flight speeds over a wide range of sizes and frequencies. To support a given mass, larger machines need less power, but smaller ones operating at higher frequencies will reach faster speeds. PMID:10562527

  6. Fuel Cell Propulsion Systems for an All-Electric Personal Air Vehicle

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa L.

    2003-01-01

    There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

  7. Fixed membrane wings for micro air vehicles: Experimental characterization, numerical modeling, and tailoring

    NASA Astrophysics Data System (ADS)

    Stanford, Bret; Ifju, Peter; Albertani, Roberto; Shyy, Wei

    2008-05-01

    Fixed wing micro air vehicles (wingspan between 10 and 15 cm) are aerodynamically challenging due to the low Reynolds number regime (10 4-10 5) they operate in. The low aspect ratio wings (typically used to maximize area under a size constraint) promote strong tip vortices, and are susceptible to rolling instabilities. Wind gusts can be of the same order of magnitude as the flight speed (10-15 m/s). Standard control surfaces on an empennage must be eliminated for size considerations and drag reduction, and the range of stable center of gravity locations is only a few millimeters long. Membrane aeroelasticity has been identified as a tenable method to alleviate these issues: flexible wing structures with geometric twist (adaptive washout for gust rejection, delayed stall) and aerodynamic twist (adaptive inflation for high lift, larger stability margins) are both considered here. Recent investigations in static aeroelastic characterization, including flight loads, wing deformation, flow structures, aeroelastic-tailoring studies through laminate orientation, as well as unconventional techniques based on membrane pre-tension, are reviewed. Multi-objective optimization aimed at improving lift, drag, and pitching moment considerations is also discussed.

  8. On the mechanics, computational modeling, and design implementation of piezoelectric actuators on micro air vehicles

    NASA Astrophysics Data System (ADS)

    Lacroix, Bradley W.

    This document details the research performed on applying piezoelectric macro fiber composite actuators on micro air vehicles. The research objective was to apply the minimum number of macro fiber composites to the aircraft in an optimized manner in order to obtain complete control authority. To do this, a local-global approach was taken. Numerical predictions, experiments, and finite element models were used to model the macro fiber composites in a local manner, approximating the curvature of the actuator when bonded to a substrate. The substrate was selected to maximize the curvature when submitted to expected loads. In a global manner, the design of the aircraft was optimized, using a computational model, to provide the largest control authority under expected flight conditions. A variety of experimental tests were conducted to create an accurate aeroelastic computer model, including tests to determine material properties, static loading tests, and wind tunnel testing. Two of the optimized designs were tested in the wind tunnel to verify the predicted improvement, which confirmed the accuracy of the computer model. Other experimental results are also included, including experiments examining the unimorph fabrication technique, rigid assumptions used for the aerodynamic model, and high frequency dynamics of the macro fiber composite unimorph.

  9. Dynamic stability test results on an 0.024 scale B-1 air vehicle

    NASA Technical Reports Server (NTRS)

    Beeman, R. R.

    1972-01-01

    Dynamic longitudinal and lateral-directional stability characteristics of the B-1 air vehicle were investigated in three wind tunnels at the Langley Research Center. The main rotary derivatives were obtained for an angle of attack range of -3 degrees to +16 degrees for a Mach number range of 0.2 to 2.16. Damping in roll data could not be obtained at the supersonic Mach numbers. The Langley 7 x 10 foot high speed tunnel, the 8 foot transonic pressure tunnel, and the 4 foot Unitary Plan wind tunnel were the test sites. An 0.024 scale light-weight model was used on a forced oscillation type balance. Test Reynolds number varied from 474,000/ft to 1,550,000/ft. through the Mach number range tested. The results showed that the dynamic stability characteristics of the model in pitch and roll were generally satisfactory up to an angle attack of about +6 degrees. In the wing sweep range from 15 to 25 degrees the positive damping levels in roll deteriorated rapidly above +2 degrees angle of attack. This reduction in roll damping is believed to be due to the onset of separation over the wing as stall is approached.

  10. Design and performance of an insect-inspired nano air vehicle

    NASA Astrophysics Data System (ADS)

    Bontemps, A.; Vanneste, T.; Paquet, J.-B.; Dietsch, T.; Grondel, S.; Cattan, E.

    2013-01-01

    This work reports the structural design, actuation and performance of an insect-inspired nano air vehicle. For this purpose, an original design concept of resonant wings using indirect actuation and concise transmission to allow large and symmetrical bending angles, passive wing torsion and to minimize energy expenditure is presented. A simplified analytical model and a numerical approach for the transmission between the actuator and the wings are then proposed to validate the design. The all-polymer prototypes were obtained using micromachining SU-8 photoresist technology. An electromagnetic actuator was added to control the vibrating amplitudes and create passive wing torsion. The actuator was optimized to make it more effective whilst at the same time minimizing its mass. Prototypes with a global wingspan of 3.5 cm and a mass of 22 mg due to the structure and actuator are presented. Bending amplitudes of the wings up to 60° were measured with these prototypes. The resonant frequency of the wings varied according to the design and mass. It was demonstrated that it is possible to obtain, without an important driving mechanism a very promising kinematics.

  11. Multisensor 3D tracking for counter small unmanned air vehicles (CSUAV)

    NASA Astrophysics Data System (ADS)

    Vasquez, Juan R.; Tarplee, Kyle M.; Case, Ellen E.; Zelnio, Anne M.; Rigling, Brian D.

    2008-04-01

    A variety of unmanned air vehicles (UAVs) have been developed for both military and civilian use. The typical large UAV is typically state owned, whereas small UAVs (SUAVs) may be in the form of remote controlled aircraft that are widely available. The potential threat of these SUAVs to both the military and civilian populace has led to research efforts to counter these assets via track, ID, and attack. Difficulties arise from the small size and low radar cross section when attempting to detect and track these targets with a single sensor such as radar or video cameras. In addition, clutter objects make accurate ID difficult without very high resolution data, leading to the use of an acoustic array to support this function. This paper presents a multi-sensor architecture that exploits sensor modes including EO/IR cameras, an acoustic array, and future inclusion of a radar. A sensor resource management concept is presented along with preliminary results from three of the sensors.

  12. Fuel Cell Propulsion Systems for an All-electric Personal Air Vehicle

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa L.; Schmitz, Paul C.

    2003-01-01

    There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

  13. 4D metrology of flapping-wing micro air vehicle based on fringe projection

    NASA Astrophysics Data System (ADS)

    Zhang, Qican; Huang, Lei; Chin, Yao-Wei; Keong, Lau-Gih; Asundi, Anand

    2013-06-01

    Inspired by dominant flight of the natural flyers and driven by civilian and military purposes, micro air vehicle (MAV) has been developed so far by passive wing control but still pales in aerodynamic performance. Better understanding of flapping wing flight mechanism is eager to improve MAV's flight performance. In this paper, a simple and effective 4D metrology technique to measure full-field deformation of flapping membrane wing is presented. Based on fringe projection and 3D Fourier analysis, the fast and complex dynamic deformation, including wing rotation and wing stroke, of a flapping wing during its flight can be accurately reconstructed from the deformed fringe patterns recorded by a highspeed camera. An experiment was carried on a flapping-wing MAV with 5-cm span membrane wing beating at 30 Hz, and the results show that this method is effective and will be useful to the aerodynamicist or micro aircraft designer for visualizing high-speed complex wing deformation and consequently aid the design of flapping wing mechanism to enhanced aerodynamic performance.

  14. Measurements and performance prediction of an adaptive wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Shkarayev, Sergey V.; Jouse, Wayne C.; Null, William R.; Wagner, Matthew G.

    2003-08-01

    The mission space requirements imposed on the design of micro air vehicles (MAVs) typically consist of several distinct flight segments that generally conflict: the transit phases of flight require high speeds, while the loiter/surveillance phase requires lower flight velocities. Maximum efficiency must be sought in order to prolong battery life and aircraft endurance. The adaptive wing MAV developed at the University of Arizona features a thin, deformable flying wing with an efficient rudder-elevator control system. The wing camber is varied to accommodate different flight speeds while maintaining a constant total lift at a relatively low angle of attack. A new airfoil was developed from the Selig 5010 that features a small negative pitching moment for pitch stability. Wind tunnel tests were performed and stall angles and best lift-to-drag ratios were analyzed from the data. The wind tunnel data was used in a performance analysis in order to determine the flight speeds and throttle settings for maximum endurance at each camber, as well as the MAV's theoretical minimum and maximum flight speeds. The effectiveness of camber change on flight speed and endurance was examined with promising results; flight speed could be reduced by 25% by increasing the camber from 3 to 9% without any increase in power consumption.

  15. Air bearing vacuum seal assembly

    DOEpatents

    Booth, Rex

    1978-01-01

    An air bearing vacuum seal assembly capable of rotating at the speed of several thousand revolutions per minute using an air cushion to prevent the rotating and stationary parts from touching, and a two stage differential pumping arrangement to maintain the pressure gradient between the air cushion and the vacuum so that the leak rate into the vacuum is, for example, less than 1 .times. 10.sup.-4 Pa m.sup.3 /s. The air bearing vacuum seal has particular application for mounting rotating targets to an evacuated accelerator beam tube for bombardment of the targets with high-power charged particle beams in vacuum.

  16. Utilization Assessment of Target Electrification Vehicles at Naval Air Station Whidbey Island: Task 3

    SciTech Connect

    Schey, Steve

    2015-05-01

    Several U.S. Department of Defense based studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of the charging infrastructure required to support this replacement, which is the subject of a separate report.

  17. Dual rotor single- stator axial air gap PMSM motor/generator drive for high torque vehicles applications

    NASA Astrophysics Data System (ADS)

    Tutelea, L. N.; Deaconu, S. I.; Boldea, I.; Popa, G. N.

    2014-03-01

    The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors, destined for hybrid electric vehicles (HEV) and military vehicles applications. The proposed topologies and the magneto-motive force analysis are the core of the paper.

  18. On mathematical modelling of insect flight dynamics in the context of micro air vehicles.

    PubMed

    Zbikowski, Rafał; Ansari, Salman A; Knowles, Kevin

    2006-06-01

    We discuss some aspects of mathematical modelling relevant to the dynamics of insect flight in the context of insect-like flapping-wing micro air vehicles (MAVs). MAVs are small flying vehicles developed to reconnoître in confined spaces. This requires power-efficient, highly-manoeuvrable, low-speed flight with stable hover. All of these attributes are present in insect flight and hence the focus on reproducing the functionality of insect flight by engineering means. Empirical research on insect flight dynamics is limited by experimental difficulties. Force and moment measurements require tethering the animal whose behaviour may then differ from free flight. The measurements are made when the insect actively tries to control its flight, so that its open-loop dynamics cannot be observed. Finally, investigation of the sensory-motor system responsible for flight is even more challenging. Despite these difficulties, much empirical progress has been made recently. Further progress, especially in the context of MAVs, can be achieved by the complementary information derived from appropriate mathematical modelling. The focus here is on a means of computing the data not easily available from experiments and also on making mathematical predictions to suggest new experiments. We consider two aspects of mathematical modelling for insect flight dynamics. The first one is theoretical (computational), as opposed to empirical, generation of the aerodynamic data required for the six-degrees-of-freedom equations of motion. For this purpose we first explain insect wing kinematics and the salient features of the corresponding flow. In this context, we show that aerodynamic modelling is a feasible option for certain flight regimes, focusing on a successful example of modelling hover. Such modelling progresses from the first principles of fluid mechanics, but relies on simplifications justified by the known flow phenomenology and/or geometric and kinematic symmetries. This is relevant to six types of fundamental manoeuvres, which we define as those flight conditions for which only one component of the translational and rotational body velocities is nonzero and constant. The second aspect of mathematical modelling for insect flight dynamics addressed here deals with the periodic character of the aerodynamic force and moment production. This leads to consideration of the types of solutions of nonlinear equations forced by nonlinear oscillations. In particular, the mechanism of synchronization seems relevant and should be investigated further. PMID:17671303

  19. Double Cushions Preserve Transmembrane Protein Mobility in Supported Bilayer Systems

    PubMed Central

    Diaz, Arnaldo J.; Albertorio, Fernando; Daniel, Susan; Cremer, Paul S.

    2012-01-01

    Supported lipid bilayers (SLBs) have been widely used as model systems to study cell membrane processes because they preserve the same 2D membrane fluidity found in living cells. One of the most significant limitations of this platform, however, is its inability to incorporate mobile transmembrane species. It is often postulated that transmembrane proteins reconstituted in SLBs lose their mobility because of direct interactions between the protein and the underlying substrate. Herein, we demonstrate a highly mobile fraction for a transmembrane protein, annexin V. Our strategy involves supporting the lipid bilayer on a double cushion, where we not only create a large space to accommodate the transmembrane portion of the macromolecule but also passivate the underlying substrate to reduce nonspecific proteinsubstrate interactions. The thickness of the confined water layer can be tuned by fusing vesicles containing polyethyleneglycol (PEG)-conjugated lipids of various molecular weights to a glass substrate that has first been passivated with a sacrificial layer of bovine serum albumin (BSA). The 2D fluidity of these systems was characterized by fluorescence recovery after photobleaching (FRAP) measurements. Uniform, mobile phospholipid bilayers with lipid diffusion coefficients of around 3 10?8 cm2/s and percent mobile fractions of over 95% were obtained. Moreover, we obtained annexin V diffusion coefficients that were also around 3 10?8 cm2/s with mobile fractions of up to 75%. This represents a significant improvement over bilayer platforms fabricated directly on glass or using single cushion strategies. PMID:18510376

  20. Test methodology for evaluation of fireworthy aircraft seat cushions

    NASA Technical Reports Server (NTRS)

    Kourtides, D. A.; Parker, J. A.

    1982-01-01

    Aircraft seat materials were evaluated in terms of their thermal performance. The materials were evaluated using (a) thermogravimetric analysis, (b) differential scanning calorimetry, (c) a modified NBS smoke chamber to determine the rate of mass loss and (d) the NASA T-3 apparatus to determine the thermal efficiency. In this paper, the modified NBS smoke chamber will be described in detail since it provided the most conclusive results. The NBS smoke chamber was modified to measure the weight loss of materials when exposed to a radiant heat source over the range of 2.5 to 7.5 W/cm sq. This chamber has been utilized to evaluate the thermal performance of various heat blocking layers utilized to protect the polyurethane cushioning foam used in aircraft seats. Various kinds of heat blocking layers were evaluated by monitoring the weight loss of miniature seat cushions when exposed to the radiant heat. The effectiveness of aluminized heat blocking systems was demonstrated when compared to conventional heat blocking layers such as neoprene. All heat blocking systems showed good fire protection capabilities when compared to the state-of-the-art, i.e., wool-nylon over polyurethane foam.

  1. 78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... from inventories developed for the Final Cross-State Air Pollution Rule (76 FR 48208, August 8, 2011... reductions. \\7\\ 65 FR 6698 (February 10, 2000). The proposed Tier 3 standards include new light- and heavy... emissions standards.\\10\\ \\8\\ 77 FR 62623 (October 15, 2012). \\9\\ These states include Connecticut,...

  2. Air-breathing hypersonic vehicle guidance and control studies: An integrated trajectory/control analysis methodology, phase 2

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    An integrated trajectory/control analysis algorithm has been used to generate trajectories and desired control strategies for two different hypersonic air-breathing vehicle models and orbit targets. Both models used cubic spline curve fit tabulated winged-cone accelerator vehicle representations. Near-fuel-optimal, horizontal takeoff trajectories, imposing a dynamic pressure limit of 1000 psf, were developed. The first model analysis case involved a polar orbit and included the dynamic effects of using elevons to maintain longitudinal trim. Analysis results indicated problems with the adequacy of the propulsion model and highlighted dynamic pressure/altitude instabilities when using vehicle angle of attack as a control variable. Also, the magnitude of computed elevon deflections to maintain trim suggested a need for alternative pitch moment management strategies. The second analysis case was reformulated to use vehicle pitch attitude relative to the local vertical as the control variable. A new, more realistic, air-breathing propulsion model was incorporated. Pitch trim calculations were dropped and an equatorial orbit was specified. Changes in flight characteristics due to the new propulsion model have been identified. Flight regimes demanding rapid attitude changes have been noted. Also, some issues that would affect design of closed-loop controllers were ascertained.

  3. Air-breathing hypersonic vehicle guidance and control studies; An integrated trajectory/control analysis methodology: Phase 1

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1991-01-01

    A tool which generates optimal trajectory/control histories in an integrated manner is generically adapted to the treatment of single-stage-to-orbit air-breathing hypersonic vehicles. The methodology is implemented as a two point boundary value problem solution technique. Its use permits an assessment of an entire near-minimum-fuel trajectory and desired control strategy from takeoff to orbit while satisfying physically derived inequality constraints and while achieving efficient propulsive mode phasing. A simpler analysis strategy that partitions the trajectory into several boundary condition matched segments is also included to construct preliminary trajectory and control history representations with less computational burden than is required for the overall flight profile assessment. A demonstration was accomplished using a tabulated example (winged-cone accelerator) vehicle model that is combined with a newly developed multidimensional cubic spline data smoothing routine. A constrained near-fuel-optimal trajectory, imposing a dynamic pressure limit of 1000 psf, was developed from horizontal takeoff to 20,000 ft/sec relative air speed while aiming for a polar orbit. Previously unspecified propulsive discontinuities were located. Flight regimes demanding rapid attitude changes were identified, dictating control effector and closed-loop controller authority was ascertained after evaluating effector use for vehicle trim. Also, inadequacies in vehicle model representations and specific subsystem models with insufficient fidelity were determined based on unusual control characteristics and/or excessive sensitivity to uncertainty.

  4. Police officer in-vehicle discomfort: appointments carriage method and vehicle seat features.

    PubMed

    Filtness, A J; Mitsopoulos-Rubens, E; Rudin-Brown, C M

    2014-07-01

    Musculoskeletal pain is commonly reported by police officers. A potential cause of officer discomfort is a mismatch between vehicle seats and the method used for carrying appointments. Twenty-five police officers rated their discomfort while seated in: (1) a standard police vehicle seat, and (2) a vehicle seat custom-designed for police use. Discomfort was recorded in both seats while wearing police appointments on: (1) a traditional appointments belt, and (2) a load-bearing vest/belt combination (LBV). Sitting in the standard vehicle seat and carrying appointments on a traditional appointments belt were both associated with significantly elevated discomfort. Four vehicle seat features were most implicated as contributing to discomfort: back rest bolster prominence; lumbar region support; seat cushion width; and seat cushion bolster depth. Authorising the carriage of appointments using a LBV is a lower cost solution with potential to reduce officer discomfort. Furthermore, the introduction of custom-designed vehicle seats should be considered. PMID:24681072

  5. Testing of aircraft passenger seat cushion material, full scale. Data, volume 2

    NASA Technical Reports Server (NTRS)

    Schutter, K. J.; Gaume, J. G.; Duskin, F. E.

    1980-01-01

    Burn characteristics of presently used and proposed seat cushion materials and types of constructions were determined. Eight different seat cushion configurations were subjected to full scale burn tests. Each cushion configuration was tested twice for a total of 16 tests. Two different fire sources were used: Jet A-fuel for eight tests, and a radiant energy source with propane flame for eight tests. Data were recorded for smoke density, cushion temperatures, radiant heat flux, animal response to combustion products, rate of weight loss of test specimens, cabin temperature, and type and content of gas within the cabin. When compared to existing seat cushions, the test specimens incorporating a fire barrier and those fabricated from advanced materials, using improved construction methods, exhibited significantly greater fire resistance. Flammability comparison tests were conducted upon one fire blocking configuration and one polyimide configuration.

  6. Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

  7. Microbes on the cliff: alpine cushion plants structure bacterial and fungal communities.

    PubMed

    Roy, J; Albert, C H; Ibanez, S; Saccone, P; Zinger, L; Choler, P; Clment, J-C; Lavergne, S; Geremia, R A

    2013-01-01

    Plants affect the spatial distribution of soil microorganisms, but the influence of the local abiotic context is poorly documented. We investigated the effect of a single plant species, the cushion plant Silene acaulis, on habitat conditions, and microbial community. We collected soil from inside (In) and outside (Out) of the cushions on calcareous and siliceous cliffs in the French Alps along an elevation gradient (2,000-3,000?masl). The composition of the microbial communities was assessed by Capillary-Electrophoresis Single Strand Conformation Polymorphism (CE-SSCP). Univariate and multivariate analyses were conducted to characterize the response of the microbial beta-diversity to soil parameters (total C, total N, soil water content, [Formula: see text], and pH). Cushions affected the microbial communities, modifying soil properties. The fungal and bacterial communities did not respond to the same abiotic factors. Outside the cushions, the bacterial communities were strongly influenced by bedrock. Inside the cushions, the bacterial communities from both types of bedrock were highly similar, due to the smaller pH differences than in open areas. By contrast, the fungal communities were equally variable inside and outside of the cushions. Outside the cushions, the fungal communities responded weakly to soil pH. Inside the cushions, the fungal communities varied strongly with bedrock and elevation as well as increases in soil nutrients and water content. Furthermore, the dissimilarities in the microbial communities between the In and Out habitats increased with increasing habitat modification and environmental stress. Our results indicate that cushions act as a selective force that counteracts the influence of the bedrock and the resource limitations on the bacterial and fungal communities by buffering soil pH and enhancing soil nutrients. Cushion plants structure microbial communities, and this effect increases in stressful, acidic and nutrient-limited environments. PMID:23543612

  8. Microbes on the Cliff: Alpine Cushion Plants Structure Bacterial and Fungal Communities

    PubMed Central

    Roy, J.; Albert, C. H.; Ibanez, S.; Saccone, P.; Zinger, L.; Choler, P.; Clment, J.-C.; Lavergne, S.; Geremia, R. A.

    2013-01-01

    Plants affect the spatial distribution of soil microorganisms, but the influence of the local abiotic context is poorly documented. We investigated the effect of a single plant species, the cushion plant Silene acaulis, on habitat conditions, and microbial community. We collected soil from inside (In) and outside (Out) of the cushions on calcareous and siliceous cliffs in the French Alps along an elevation gradient (2,0003,000?masl). The composition of the microbial communities was assessed by Capillary-Electrophoresis Single Strand Conformation Polymorphism (CE-SSCP). Univariate and multivariate analyses were conducted to characterize the response of the microbial beta-diversity to soil parameters (total C, total N, soil water content, N-NH4+,N-NO3-, and pH). Cushions affected the microbial communities, modifying soil properties. The fungal and bacterial communities did not respond to the same abiotic factors. Outside the cushions, the bacterial communities were strongly influenced by bedrock. Inside the cushions, the bacterial communities from both types of bedrock were highly similar, due to the smaller pH differences than in open areas. By contrast, the fungal communities were equally variable inside and outside of the cushions. Outside the cushions, the fungal communities responded weakly to soil pH. Inside the cushions, the fungal communities varied strongly with bedrock and elevation as well as increases in soil nutrients and water content. Furthermore, the dissimilarities in the microbial communities between the In and Out habitats increased with increasing habitat modification and environmental stress. Our results indicate that cushions act as a selective force that counteracts the influence of the bedrock and the resource limitations on the bacterial and fungal communities by buffering soil pH and enhancing soil nutrients. Cushion plants structure microbial communities, and this effect increases in stressful, acidic and nutrient-limited environments. PMID:23543612

  9. Electroactive polymers as a novel actuator technology for lighter-than-air vehicles

    NASA Astrophysics Data System (ADS)

    Michel, Silvain; Drager, Christian; Zobel, Martin; Fink, Erich

    2007-04-01

    In this paper the worldwide first EAP actuated blimp will be presented. It consists of a slightly pressurized Helium filled body of a biologically inspired form with Dielectric Elastomer (DE) actuators driving a classical cross tail with two vertical and horizontal rudders for flight control. Two versions of actuators will be discussed: The first version consisted of "spring-roll" type of cylindrical actuators placed together with the electrical supply and control unit in the pay load gondola. The second version consisted of a configuration, where the actuators are placed between the control surfaces and the rudders. This novel type of EAP actuator named "active hinge" was developed and characterized first in the laboratory and afterwards optimized for minimum weight and finally integrated in the blimp structure. In the design phase a numerical simulation tool for the prediction of the DE actuators was developed based on a material model calibrated with the test results from cylindrical actuators. The electrical supply and control system was developed and optimized for minimum of weight. Special attention was paid to the electromagnetic systems compatibility of the high voltage electrical supply system of the DE actuators and the radio flight control system. The design and production of this 3.5 meter long Lighter-than-Air vehicle was collaboration between Empa Duebendorf Switzerland and the Technical University of Berlin. The first version of this EAP blimp first flew at an RC airship regatta hold on 24 th of June 2006 in Dresden Germany, while the second version had his maiden flight on 8 th of January 2007 in Duebendorf Switzerland. In both cases satisfactory flight control performances were demonstrated.

  10. Emerging Fuel Cell Technology Being Developed: Offers Many Benefits to Air Vehicles

    NASA Technical Reports Server (NTRS)

    Walker, James F.; Civinskas, Kestutis C.

    2004-01-01

    Fuel cells, which have recently received considerable attention for terrestrial applications ranging from automobiles to stationary power generation, may enable new aerospace missions as well as offer fuel savings, quiet operations, and reduced emissions for current and future aircraft. NASA has extensive experience with fuel cells, having used them on manned space flight systems over four decades. Consequently, the NASA Glenn Research Center has initiated an effort to investigate and develop fuel cell technologies for multiple aerospace applications. Two promising fuel cell types are the proton exchange membrane (PEM) and solid oxide fuel cell (SOFC). PEM technology, first used on the Gemini spacecraft in the sixties, remained unutilized thereafter until the automotive industry recently recognized the potential. PEM fuel cells are low-temperature devices offering quick startup time but requiring relatively pure hydrogen fuel. In contrast, SOFCs operate at high temperatures and tolerate higher levels of impurities. This flexibility allows SOFCs to use hydrocarbon fuels, which is an important factor considering our current liquid petroleum infrastructure. However, depending on the specific application, either PEM or SOFC can be attractive. As only NASA can, the Agency is pursuing fuel cell technology for civil uninhabited aerial vehicles (UAVs) because it offers enhanced scientific capabilities, including enabling highaltitude, long-endurance missions. The NASA Helios aircraft demonstrated altitudes approaching 100,000 ft using solar power in 2001, and future plans include the development of a regenerative PEM fuel cell to provide nighttime power. Unique to NASA's mission, the high-altitude aircraft application requires the PEM fuel cell to operate on pure oxygen, instead of the air typical of terrestrial applications.

  11. Bio-inspired multi-mode optic flow sensors for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Park, Seokjun; Choi, Jaehyuk; Cho, Jihyun; Yoon, Euisik

    2013-06-01

    Monitoring wide-field surrounding information is essential for vision-based autonomous navigation in micro-air-vehicles (MAV). Our image-cube (iCube) module, which consists of multiple sensors that are facing different angles in 3-D space, can be applied to the wide-field of view optic flows estimation (μ-Compound eyes) and to attitude control (μ- Ocelli) in the Micro Autonomous Systems and Technology (MAST) platforms. In this paper, we report an analog/digital (A/D) mixed-mode optic-flow sensor, which generates both optic flows and normal images in different modes for μ- Compound eyes and μ-Ocelli applications. The sensor employs a time-stamp based optic flow algorithm which is modified from the conventional EMD (Elementary Motion Detector) algorithm to give an optimum partitioning of hardware blocks in analog and digital domains as well as adequate allocation of pixel-level, column-parallel, and chip-level signal processing. Temporal filtering, which may require huge hardware resources if implemented in digital domain, is remained in a pixel-level analog processing unit. The rest of the blocks, including feature detection and timestamp latching, are implemented using digital circuits in a column-parallel processing unit. Finally, time-stamp information is decoded into velocity from look-up tables, multiplications, and simple subtraction circuits in a chip-level processing unit, thus significantly reducing core digital processing power consumption. In the normal image mode, the sensor generates 8-b digital images using single slope ADCs in the column unit. In the optic flow mode, the sensor estimates 8-b 1-D optic flows from the integrated mixed-mode algorithm core and 2-D optic flows with an external timestamp processing, respectively.

  12. The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Miller, Daniel N.; Gridley, Marvin C.; Agrell, Johan

    2003-01-01

    It is the purpose of this study to demonstrate the viability and economy of Design-of-Experiments methodologies to arrive at microscale secondary flow control array designs that maintain optimal inlet performance over a wide range of the mission variables and to explore how these statistical methods provide a better understanding of the management of flow in compact air vehicle inlets. These statistical design concepts were used to investigate the robustness properties of low unit strength micro-effector arrays. Low unit strength micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. The term robustness is used in this paper in the same sense as it is used in the industrial problem solving community. It refers to minimizing the effects of the hard-to-control factors that influence the development of a product or process. In Robustness Engineering, the effects of the hard-to-control factors are often called noise , and the hard-to-control factors themselves are referred to as the environmental variables or sometimes as the Taguchi noise variables. Hence Robust Optimization refers to minimizing the effects of the environmental or noise variables on the development (design) of a product or process. In the management of flow in compact inlets, the environmental or noise variables can be identified with the mission variables. Therefore this paper formulates a statistical design methodology that minimizes the impact of variations in the mission variables on inlet performance and demonstrates that these statistical design concepts can lead to simpler inlet flow management systems.

  13. Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.

    SciTech Connect

    Poola, R.; Stork, K.

    1998-11-09

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM2.5). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles. For nearly a decade, Argonne has been evaluating membrane-based methods to control the composition of air used in combustion. Membranes are the only practical method of modifying air composition for on-board use. The applicability of the technique depends strongly on both the technical and economic feasibility of implementing it on a vehicle. Over the past 10 years, significant technical advances have been made in the development of air-separation membranes. Researchers have developed and commercialized novel membrane materials that can efficiently separate air at the concentrations required for vehicle applications and have developed compact membrane modules that can be incorporated into vehicle design. Previous analysis by Argonne and others has demonstrated the effectiveness of oxygen enrichment at reducing PM, smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions while increasing engine power output. Under appropriate oxygen-enriched operating conditions, diesel engines have achieved a net increase of 10-20% in power density and a decrease of 30-60% in PM emissions. Nitrogen-enriched air can be used as an alternative to exhaust gas recirculation to control NO{sub x} emissions and can also be used to generate a monatomic nitrogen plasma for exhaust post-treatment to reduce emissions of NO{sub x}. Argonne has recently identified an operating regime that can simultaneously reduce NO{sub x} and PM while increasing power output when oxygen-enriched combustion air is used. This promising technique, which will be verified by additional experimental work at Argonne (using a range of engine sizes), will require the use of membranes similar to those analyzed in this study.

  14. 78 FR 34911 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ...EPA is approving State Implementation Plan (SIP) revisions submitted by the State of Maryland on December 20, 2007, November 12, 2010, and June 22, 2011, as amended March 22, 2013. These SIP revisions pertain to adoption by Maryland of a Low Emission Vehicle (LEV) program, which incorporates by reference California's second generation Low Emission Vehicle (LEVII) program regulations.......

  15. 77 FR 50969 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ... subsequent model year passenger cars, light trucks, and medium-duty vehicles having a gross vehicle weight... it in the body of your comment. If you send an email comment directly to EPA without going through... electronic comment, EPA recommends that you include your name and other contact information in the body...

  16. Air pollution from motor vehicles: Standards and technologies for controlling emissions

    SciTech Connect

    Faiz, A.; Weaver, C.S.; Walsh, M.; Gautam, S.; Chan, L.

    1997-01-01

    This book presents a state-of-the art review of vehicle emission standards and regulations and provides a synthesis of worldwide experience with vehicle emission control technologies and their applications in both industrial and developing countries. Topics covered include: The two principal international systems of vehicle emission standards: those of North America and Europe; Test procedures used to verify compliance with emissions standards and to estimate actual emissions; Engine and aftertreatment technologies that have been developed to enable new vehicles to comply with emission standards, as well as the cost and other impacts of these technologies; An evaluation of measures for controlling emissions from in-use vehicles; The role of fuels in reducing vehicle emissions, the benefits that could be gained by reformulating conventional gasoline and diesel fuels, the potential benefits of alternative cleaner fuels, and the prospects for using hydrogen and electric power to run motor vehicles with ultra-low or zero emissions. This book is the first in a series of publications on vehicle-related pollution and control measures prepared by the World Bank in collaboration with the United Nations Environment Programme to underpin the Bank`s overall objective of promoting transport that is environmentally sustainable and least damaging to human health and welfare.

  17. Next Generation Natural Gas Vehicle Program Phase I: Clean Air Partners 0.5 g/hp-h NOx Engine Concept; Final Report

    SciTech Connect

    Wong, H. C.

    2003-07-01

    Subcontractor report details work done by Clean Air Partners to develop 0.5 g/hp-h NOx natural gas engine exhaust gas recirculation (EGR) technology for the Next Generation Natural Gas Vehicle Program.

  18. Characterizing the spatial variation of air pollutants and the contributions of high emitting vehicles in Pittsburgh, PA.

    PubMed

    Tan, Yi; Lipsky, Eric M; Saleh, Rawad; Robinson, Allen L; Presto, Albert A

    2014-12-16

    We used a mobile measurement platform to characterize a suite of air pollutants (black carbon (BC), particle-bound polycyclic aromatic hydrocarbons (PB-PAH), benzene, and toluene) in the city of Pittsburgh and surrounding areas. More than 270 h of data were collected from forty-two sites which were selected based on analysis in the geographic information system (GIS). Mobile measurements were performed during three different times of day (mornings, afternoons/evenings, and overnight) in both winter (November 2011 to February 2012) and summer (June 2012 to August 2012). Pollutant concentrations were elevated in river valleys by 9% (benzene) to 30% (PB-PAH) relative to upland areas. Traffic had strong impacts on measured pollutants. PB-PAH and BC concentrations at high traffic sites were a factor of 2 and 30% higher than at low traffic sites, respectively. Pollutant concentrations were highest in the morning sessions due to a combination of traffic and meteorological conditions. The highly time-resolved data indicated that elevated pollutant concentrations at high traffic sites were due to short duration plume events associated with high emitting vehicles. High emitting vehicles contributed up to 70% of the near road PB-PAH and 30% of BC; emissions from these vehicles drove substantial spatial variations in BC and PB-PAH concentrations. Many high emitting vehicles were presumably diesel trucks or buses, because plumes were strongly correlated with truck traffic volume. In contrast, PB-PAH and BC in the nonplume background air was weakly correlated with traffic, and their spatial patterns were more influenced by terrain and point source emissions. The spatial variability in contributions of high emitting vehicles suggests that the effect of potential control strategies vary for different pollutants and environments. PMID:25393032

  19. Air quality impacts of using overnight electricity generation to charge plug-in hybrid electric vehicles for daytime use

    NASA Astrophysics Data System (ADS)

    Thompson, Tammy; Webber, Michael; Allen, David T.

    2009-01-01

    The air quality impacts of replacing 20% of the gasoline powered light duty vehicle miles traveled with plug-in hybrid electric vehicles (PHEVs) in the region served by the Pennsylvania, New Jersey, Maryland classic grid are examined. Unutilized, base-load nighttime electricity generating capacity is assumed to charge PHEVs that would subsequently be used during urban commutes. The net impact of this scenario on the emissions of precursors to the formation of ozone is an increase in nitrogen oxide (NOx), volatile organic compound (VOC) and CO emissions from electricity generating units during nighttime hours, and a greater decrease in NOx, VOC and CO from mobile emissions in urban areas during daytime hours. The changes in maximum daily 8 h ozone concentrations, predicted using a regional photochemical model (CAMx), are decreases in ozone concentrations between 2 and 6 ppb that are widespread across the urban areas, and increases in ozone concentrations of up to 8 ppb in highly localized areas. Air quality indicators beyond maximum daily ozone concentration are also evaluated, and in general indicate air quality improvements associated with the use of PHEVs. However, a limited number of air quality indicators worsened with the use of PHEVs, suggesting that overall impacts of the use of PHEVs will be complex.

  20. Viking entry vehicle aerodynamics at m equals 2 in air and some preliminary test data for flight in CO2

    NASA Technical Reports Server (NTRS)

    Sammonds, R. I.; Kruse, R. L.

    1975-01-01

    The static and dynamic aerodynamic characteristics of the Viking entry vehicle were determined experimentally in free flight in air at a Mach number near 2. Preliminary results were also obtained in CO2 at M infinity = 11. The low speed tests in air confirmed a region of dynamic instability previously observed. The instability was greatest at the smallest pitch amplitudes but decreased with increasing amplitude until a limit cycle was reached at about 8 deg. The tests in CO2 indicated increased drag coefficients of 3 percent with respect to those in air. Errors in the drag coefficient of this magnitude would significantly affect the reconstruction of the Martian atmosphere during entry of the Viking spacecraft.

  1. Investigation of the Landing Characteristics of a Re-entry Vehicle Having a Canted Multiple Air Bag Load Alleviation System

    NASA Technical Reports Server (NTRS)

    McGehee, John R.; Stubbs, Sandy M.

    1963-01-01

    An investigation was made to determine the landing-impact characteristics of a reentry vehicle having a multiple-air-bag load-alleviation system. A 1/16-scale dynamic model having four canted air bags was tested at flight-path angles of 90 degrees (vertical), 45 degrees, and 27 degrees for a parachute or paraglider vertical letdown velocity of 30 feet per second (full scale). Landings were made on concrete at attitudes ranging from -l5 degrees to 20 degrees. The friction coefficient between the model heat shield and the concrete was approximately 0.4. An aluminum diaphragm, designed to rupture at 10.8 pounds per square inch gage, was used to maintain initial pressure in the air bags for a short time period.

  2. [Cushion-like structure in coronary arteries of rats].

    PubMed

    Tsunenari, I

    1993-02-01

    The vascular architecture in the rat heart was investigated with SEM using a corrosion cast and light microscopy of paraffin sections stained with Hematoxylin-Eosin and Elastica-Domagk methods. In corrosion cast models of the left and right descending coronary arteries, Y- and T-type branching patterns were distinguished. The Y-type bifurcations were found at branching sites of the larger vessels and precapillary arterioles in the myocardium, whereas the T-type bifurcations were found at branching sites of the smaller vessels. On the surface of the corrosion cast of the T-type bifurcation symmetrical shallow depressions were observed at an orifice of a daughter vessel. The depression was confirmed to be produced by protrusions consisting of smooth muscles and elastic fibers of the vascular wall. The structure is presumed to be an arterial cushion which plays some role in avoiding plasm skimming and regulating blood flow. PMID:8517116

  3. Ammonia emissions from a representative in-use fleet of light and medium-duty vehicles in the California South Coast Air Basin

    NASA Astrophysics Data System (ADS)

    Livingston, Cody; Rieger, Paul; Winer, Arthur

    We used Fourier Transform Infrared Spectroscopy (FTIR) to measure tailpipe ammonia emissions from a representative fleet of 41 light and medium-duty vehicles recruited in the California South Coast Air Basin. A total of 121 chassis dynamometer emissions tests were conducted on these vehicles and the test results were examined to determine the effects of several key variables on ammonia emissions. Variables included vehicle type, driving cycle, emissions technology, ammonia precursor emissions (i.e. CO and NOx) and odometer readings/model year as a proxy for catalyst age. The mean ammonia emissions factor was 46 mg km -1 ( ? = 48 mg km -1) for the vehicle fleet. Average emission factors for specific vehicle groups are also reported in this study. Results of this study suggest vehicles with the highest ammonia emission rates possess the following characteristics: medium-duty vehicles, older emissions technologies, mid-range odometer readings, and higher CO emissions. In addition, vehicles subjected to aggressive driving conditions are likely to be higher ammonia emitters. Since the vehicles we studied were representative of recent model year vehicles and technologies in urban airsheds, the results of our study will be useful for developing ammonia emissions inventories in Los Angeles and other urban areas where California-certified vehicles are driven. However, efforts should also be made to continue emissions testing on in-use vehicles to ensure greater confidence in the ammonia emission factors reported here.

  4. Factors impacting equine sperm recovery rate and quality following cushioned centrifugation.

    PubMed

    Waite, J A; Love, C C; Brinsko, S P; Teague, S R; Salazar, J L; Mancill, S S; Varner, D D

    2008-09-01

    Two experiments were conducted to investigate modifications in cushioned centrifugation of stallion semen. Specifically, the effects of tube type, centrifugation medium, cushion type, and centrifugation force on post-centrifugation sperm recovery rate and quality were evaluated. In Experiment 1, sperm recovery rate was higher (P<0.05) in conventional plastic conical-bottom tubes (103%) than in newly developed glass nipple-bottom tubes (96%) following cushioned centrifugation; however, several measures of semen quality (i.e., % total motility [MOT], % progressive motility [PMOT], curvilinear velocity, and average-path velocity) yielded higher values following centrifugation in nipple-bottom tubes (P<0.05). Sperm recovery rate following cushioned centrifugation was similar between semen previously diluted in optically clear centrifugation extender (100%) and semen diluted in opaque centrifugation extender (100%); however, MOT and PMOT were higher in semen subjected to cushioned centrifugation in opaque extender (P<0.05). An extender by tube-type interaction was not detected for recovery rate or post-centrifugation semen quality. In Experiment 2, sperm recovery rate following cushioned centrifugation in nipple-bottom tubes was similar when forces of 400xg or 600xg were applied (90 and 90%, respectively; P>0.05), and no resulting differences in semen quality were detected between these treatment groups (P>0.05). The type of iodixanol cushion medium used (i.e., OptiPrep, Eqcellsire Component B, or Cushion Fluid did not impact post-centrifugation semen quality, based on the laboratory values measured (P>0.05). In conclusion, cushioned centrifugation of stallion semen in either conical-bottom or nipple-bottom tubes yielded a high sperm harvest, while maintaining sperm function. An optically opaque extender, commonly used in the equine breeding industry, can be used to achieve this goal. PMID:18573520

  5. Design and development of a biomimetic device for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Bohorquez, Felipe; Pines, Darryll J.

    2002-07-01

    This paper presents the design and development of a pitching and plunging (flapping) mechanism for small-scale flight. In order to harness the unsteady lift mechanisms, used by most insects, a biologically inspired flapping/pitching device in conjunction with a rotary wing concept was developed and built. This mechanism attempts to replicate some of the aerodynamic phenomena that enhance the performance of small fliers, replacing the periodic translational motion with a unidirectional circular motion while actively flapping and pitching the rotor blades. In order to find the appropriate combination of phase, amplitude, frequency and rotational speed that leads to enhancement in lift, the device requires uncoupled independent pitch and flap actuation systems to permit the complete mapping of the parameter space. In the device under consideration the phase shift between the flapping and the pitching oscillations can be adjusted from 0 to 360 degrees over a wide range of rotational speeds. Maximum flapping and pitching amplitudes of +/- 23 degree(s) and +/- 20 degree(s) respectively can be attained. Linear displacements of two coaxial shafts are translated into the flapping and pitching motion of the rotor blades. The mechanism was designed to minimize the actuation stroke so that smart materials and conventional actuators such as motors and cams could be used. Kinematic analysis as well as experimental tests were performed. Using a customized test stand thrust and torque produced by the rotor were measured at different angles of attack, in steady-state and under periodical pitching actuation. The results showed that hover efficiency was considerably increased for a range of thrust coefficients. The device was developed based on the University of Maryland's rotary wing Micro Air vehicle (MAV) the MICOR (MIcro COaxial Rotorcraft), an electrically driven 100 g coaxial helicopter. It is anticipated that active flapping and/or pitching could be implemented in the prototype to improve its aerodynamic performance. The present paper will discuss the design and development process of a rotating/pitching/flapping mechanism for MAVs. Test results indicate that unsteady pitching motion can be used to include the aerodynamic effect of delayed stall. Performance measurements confirm that unsteady pitching motion improves efficiency in hover.

  6. The optimization of aircraft seat cushion fire-blocking layers. Full Scale: Test description and results

    NASA Technical Reports Server (NTRS)

    Schutter, K. J.; Duskin, F. E.

    1982-01-01

    Full-scale burn tests were conducted on thirteen different seat cushion configurations in a cabin fire simulator. The fire source used was a quartz lamp radiant energy panel with a propane pilot flame. During each test, data were recorded for cushion temperatures, radiant heat flux, rate of weight loss of test specimens, and cabin temperatures. When compared to existing passenger aircraft seat cushions, the test specimens incorporating a fire barrier and those fabricated from advance materials, using improved construction methods, exhibited significantly greater fire resistance.

  7. 77 FR 1892 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-12

    ... of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Carbon monoxide...; ] ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans... taken under section 110 of the Clean Air Act. DATES: Comments must be received on or before February...

  8. 77 FR 75388 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-20

    ...)(2).) List of Subjects in 40 CFR Part 52 Environmental protection, Air pollution control, Carbon... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; State of Colorado... section 110 of the Clean Air Act. DATES: Effective Date: This final rule is effective January 22,...

  9. Air quality impacts of plug-in hybrid electric vehicles in Texas: evaluating three battery charging scenarios

    NASA Astrophysics Data System (ADS)

    Thompson, Tammy M.; King, Carey W.; Allen, David T.; Webber, Michael E.

    2011-04-01

    The air quality impacts of replacing approximately 20% of the gasoline-powered light duty vehicle miles traveled (VMT) with electric VMT by the year 2018 were examined for four major cities in Texas: Dallas/Ft Worth, Houston, Austin, and San Antonio. Plug-in hybrid electric vehicle (PHEV) charging was assumed to occur on the electric grid controlled by the Electricity Reliability Council of Texas (ERCOT), and three charging scenarios were examined: nighttime charging, charging to maximize battery life, and charging to maximize driver convenience. A subset of electricity generating units (EGUs) in Texas that were found to contribute the majority of the electricity generation needed to charge PHEVs at the times of day associated with each scenario was modeled using a regional photochemical model (CAMx). The net impacts of the PHEVs on the emissions of precursors to the formation of ozone included an increase in NOx emissions from EGUs during times of day when the vehicle is charging, and a decrease in NOx from mobile emissions. The changes in maximum daily 8 h ozone concentrations and average exposure potential at twelve air quality monitors in Texas were predicted on the basis of these changes in NOx emissions. For all scenarios, at all monitors, the impact of changes in vehicular emissions, rather than EGU emissions, dominated the ozone impact. In general, PHEVs lead to an increase in ozone during nighttime hours (due to decreased scavenging from both vehicles and EGU stacks) and a decrease in ozone during daytime hours. A few monitors showed a larger increase in ozone for the convenience charging scenario versus the other two scenarios. Additionally, cumulative ozone exposure results indicate that nighttime charging is most likely to reduce a measure of ozone exposure potential versus the other two scenarios.

  10. Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales

    NASA Astrophysics Data System (ADS)

    McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

    2012-09-01

    A fuel-based approach is used to estimate nitrogen oxides (NOx = NO + NO2) emissions from gasoline- and diesel-powered motor vehicles. Estimates are made at the national level for the period 1990-2010. Vehicle emissions are also estimated at the state level for California, and for the South Coast (Los Angeles) and San Joaquin Valley air basins. Fuel-based emission estimates are compared with predictions from widely used emission inventory models. Changes in diesel NOxemissions vary over time: increasing between 1990 and 1997, stable between 1997 and 2007, and decreasing since 2007. In contrast, gasoline engine-related NOxemissions have decreased steadily, by 65% overall between 1990 and 2010, except in the San Joaquin Valley, where reductions were not as large due to faster population growth. In the San Joaquin Valley, diesel engines were the dominant on-road NOxsource in all years considered (reaching 70% in 2010). In the urbanized South Coast air basin, gasoline engine emissions dominated in the past and have been comparable to on-road diesel sources since 2007 (down from 75% in 1990). Other major anthropogenic sources of NOxare added to compare emission trends with trends in surface pollutant observations and satellite-derived data. When all major anthropogenic NOx sources are included, the overall emission trend is downward in all cases (-45% to -60%). Future reductions in motor vehicle NOxwill depend on the effectiveness of new exhaust after-treatment controls on heavy-duty trucks, as well as further improvements todurabilityof emission control systems on light-duty vehicles.

  11. Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales

    NASA Astrophysics Data System (ADS)

    McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

    2011-11-01

    A fuel-based approach is used to estimate nitrogen oxides (NOx = NO + NO2) emissions from gasoline- and diesel-powered motor vehicles. Estimates are made at the national level for the period 1990-2010. Vehicle emissions are also estimated at the state level for California, and for the South Coast (Los Angeles) and San Joaquin Valley air basins. Fuel-based emission estimates are compared with predictions from widely used emission inventory models. Changes in diesel NOxemissions vary over time: increasing between 1990 and 1997, stable between 1997 and 2007, and decreasing since 2007. In contrast, gasoline engine-related NOxemissions have decreased steadily, by 65% overall between 1990 and 2010, except in the San Joaquin Valley, where reductions were not as large due to faster population growth. In the San Joaquin Valley, diesel engines were the dominant on-road NOxsource in all years considered (reaching 70% in 2010). In the urbanized South Coast air basin, gasoline engine emissions dominated in the past and have been comparable to on-road diesel sources since 2007 (down from 75% in 1990). Other major anthropogenic sources of NOxare added to compare emission trends with trends in surface pollutant observations and satellite-derived data. When all major anthropogenic NOx sources are included, the overall emission trend is downward in all cases (-45% to -60%). Future reductions in motor vehicle NOxwill depend on the effectiveness of new exhaust after-treatment controls on heavy-duty trucks, as well as further improvements todurabilityof emission control systems on light-duty vehicles.

  12. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, B. Y.; Wu, L.; Mao, H. J.; Gong, S. L.; He, J. J.; Zou, C.; Song, G. H.; Li, X. Y.; Wu, Z.

    2015-10-01

    As the ownership of vehicles and frequency of utilization increase, vehicle emissions have become an important source of air pollution in Chinese cities. An accurate emission inventory for on-road vehicles is necessary for numerical air quality simulation and the assessment of implementation strategies. This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near real time (NRT) traffic data on road segments to develop a high temporal-spatial resolution vehicle emission inventory (HTSVE) for the urban Beijing area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg, respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Additionally, the on-road vehicle emission inventory model and control effect assessment system in Beijing, a vehicle emission inventory model, was established based on this study in a companion paper (He et al., 2015).

  13. A complete passive or imaging-based sensor system for unmanned air vehicle taking off and landing operations

    NASA Astrophysics Data System (ADS)

    Yi, Steven

    2008-04-01

    We have successfully developed an innovative, miniaturized, and lightweight PTZ UCAV imager called OmniBird for unmanned air vehicle taking off and landing operations. OmniBird is developed through a SBIR funding from NAVAIR. It is to fit in 8 in 3. The designed zoom capability allows it to acquire focused images for targets ranging from 10 to 250 feet. The innovative panning mechanism also allows the system to have a field of view of +/- 100 degrees. Initial test results show that the integrated optics, camera sensor, and mechanics solution allow the OmniBird to stay optically aligned and shock-proof under harsh environments.

  14. Experimental and predicted pressure and heating distributions for an Aeroassist Flight Experiment vehicle in air at Mach 10

    NASA Technical Reports Server (NTRS)

    Micol, John R.

    1989-01-01

    The Aeroassisted Flight Experiment vehicle for whose scale model pressure and heat-transfer rate distributions have been measured in air at Mach 10 is a 60-deg elliptic cone, raked off at a 73-percent angle, with an ellipsoid nose and a skirt added to the base of the rake plane to reduce heating. The predictions of both an inviscid flow-field code and a Navier-Stokes solver are compared with measured values. Good agreement is obtained in the case of pressure distributions; the effect of Reynolds number on heat-transfer distributions is noted to be small.

  15. Testing of aircraft passenger seat cushion materials. Full scale, test description and results, volume 1

    NASA Technical Reports Server (NTRS)

    Schutter, K. J.; Gaume, J. G.; Duskin, F. E.

    1981-01-01

    Eight different seat cushion configurations were subjected to full-scale burn tests. Each cushion configuration was tested twice for a total of sixteen tests. Two different fire sources were used. They consisted of one liter of Jet A fuel for eight tests and a radiant energy source with propane flame for eight tests. Both fire sources were ignited by a propane flame. During each test, data were recorded for smoke density, cushion temperatures, radiant heat flux, animal response to combustion products, rate of weight loss of test specimens, cabin temperature, and for the type and content of gas within the cabin atmosphere. When compared to existing passenger aircraft seat cushions, the test specimens incorporating a fire barrier and those fabricated from advanced materials, using improved construction methods, exhibited significantly greater fire resistance.

  16. Numerical modeling of aerodynamics of airfoils of micro air vehicles in gusty environment

    NASA Astrophysics Data System (ADS)

    Gopalan, Harish

    The superior flight characteristics exhibited by birds and insects can be taken as a prototype of the most perfect form of flying machine ever created. The design of Micro Air Vehicles (MAV) which tries mimic the flight of birds and insects has generated a great deal of interest as the MAVs can be utilized for a number of commercial and military operations which is usually not easily accessible by manned motion. The size and speed of operation of a MAV results in low Reynolds number flight, way below the flying conditions of a conventional aircraft. The insensitivity to wind shear and gust is one of the required factors to be considered in the design of airfoil for MAVs. The stability of flight under wind shear is successfully accomplished in the flight of birds and insects, through the flapping motion of their wings. Numerous studies which attempt to model the flapping motion of the birds and insects have neglected the effect of wind gust on the stability of the motion. Also sudden change in flight conditions makes it important to have the ability to have an instantaneous change of the lift force without disturbing the stability of the MAV. In the current study, two dimensional rigid airfoil, undergoing flapping motion is studied numerically using a compressible Navier-Stokes solver discretized using high-order finite difference schemes. The high-order schemes in space and in time are needed to keep the numerical solution economic in terms of computer resources and to prevent vortices from smearing. The numerical grid required for the computations are generated using an inverse panel method for the streamfunction and potential function. This grid generating algorithm allows the creation of single-block orthogonal H-grids with ease of clustering anywhere in the domain and the easy resolution of boundary layers. The developed numerical algorithm has been validated successfully against benchmark problems in computational aeroacoustics (CAA), and unsteady viscous flows. The numerical results for pure-plunge and pure-pitching motion of SD 7003 airfoil are compared with the particle image velocimetry data of Michael Ol by plotting the contours of streamwise velocity and vorticity and also by observing the wake profile of the streamwise velocity. A very good agreement in the location of the vortices was observed between the numerical and experimental results. Also the numerical tracking of streaklines was compared with the dye injection experiments and excellent agreement in the horizontal and vertical locations of the vortex cores was observed. The importance of using the angle of attack to match the wake structures and lift forces of airfoils in pure-pitch and pure-plunge was investigated and it was found that matching the plunging amplitude with the maximum displacement of the leading edge provides a closer match in the observed wake structures and coefficient of lift. Next, the average coefficient of list of an airfoil in pure-pitch was studied and it was found that the pitching about the leading edge produced the maximum value. Two difference methods of enhancements were considered: (i) axis of rotation, and (ii) moving airfoil, as possible ways to enhance the average coefficient of lift for an airfoil pitching about its leading edge. The first case produced two times increase and the second case produced almost four times increase in the average coefficient of lift respectively. Hence these two kinds of motion can be used for lift enhancement to overcome sudden changes in the flight conditions. Finally the effect of a sinusoidal gust on an airfoil in pure-pitch and pure-plunge motion was examined. The pitching motion showed a much lesser drop in the average coefficient of lift compared to the plunging motion, suggesting its effectiveness to overcome disturbances in the freestream. The plunging motion on the other hand can be employed for cases that require the suppression of the oscillation in the lift coefficient.

  17. Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

    2004-01-01

    This paper describes an approach based on using both bias momentum and multiple control moment gyros for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The stabilization approach described in this paper uses these internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other outer loop control functions, including CMG stabilization/ desaturation under persistent external disturbances. Simulation results show the feasibility of (1) improved vehicle performance beyond bias momentum assisted vector thrusting control, and (2) using control moment gyros to significantly reduce the external torque required from the vector thrusting machinery.

  18. Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

    SciTech Connect

    Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

    1989-04-01

    This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

  19. DPPG Liposomes Adsorbed on Polymer Cushions: Effect of Roughness on Amount, Surface Composition and Topography.

    PubMed

    Duarte, Andreia A; Botelho do Rego, Ana M; Salerno, Marco; Ribeiro, Paulo A; El Bari, Nezha; Bouchikhi, Benachir; Raposo, Maria

    2015-07-01

    The adsorption of intact liposomes onto solid supports is a fundamental issue when preparing systems with encapsulated biological molecules. In this work, the adsorption kinetic of 1,2-dipalmitoyl-sn-glycero-3-[phospho-rac-(1-glycerol)] (sodium salt) liposomes onto cushions prepared from commom polyelectrolytes by the layer-by-layer technique was investigated with the main objective of finding the surface conditions leading to the adsorption of intact liposomes. For this purpose, different cushion surface roughnesses were obtained by changing the number of cushion bilayers. The adsorbed amount per unit area was measured through quartz crystal microbalance, surface morphology was characterized by atomic force microscopy, and the surface composition was assessed by X-ray photoelectron spectroscopy. The results show that (1) the amount of adsorbed lipids depends on the number of cushion bilayers, (2) the cushions are uniformly covered by the adsorbed lipids, and (3) the surface morphology of polymer cushions tunes liposome rupture and its adsorption kinetics. The fraction of ruptured liposomes, calculated from the measured amount of adsorbed lipids, is a function of surface roughness together with other surface morphology parameters, namely the dominating in-plane spatial feature size, the fractal dimension, and other textural features as well as amplitude and hybrid parameters. PMID:26076391

  20. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conditioner will be included in the equivalent test weight calculations for emission testing. ... estimated weight of that item must be included in the curb weight computation for each vehicle available... equipment or an option), no weight for that item will be added in computing the curb weight for any...

  1. ANALYSIS OF MOTOR VEHICLE EMISSIONS IN A HOUSTON TUNNEL DURING THE TEXAS AIR QUALITY STUDY 2000

    EPA Science Inventory

    Measurements from a Houston tunnel were used to develop fuel consumption based emission factors for CO, NOx, and Non-Methane Organic Compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (pr...

  2. 78 FR 11122 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... Philadelphia Area) to reflect the use of the most recent version of the Motor Vehicle Emission Simulator model... determined on May 16, 2012 (77 FR 28782) that the Philadelphia Area attained the 1997 PM 2.5 NAAQS by the... (MOBILE6.2). On March 2, 2010 (75 FR 9411), EPA published a notice of availability for the MOVES2010...

  3. 75 FR 38023 - Approval and Promulgation of Air Quality Implementation Plans; California; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-01

    ...)(2)). List of Subjects in 40 CFR Part 52 Air pollution control, Carbon monoxide, Incorporation by... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; California; Motor... ``we'', ``us'', and ``our'' refer to EPA. I. Summary of the Proposed Actions On August 19, 2009 (74...

  4. Structural studies of lipid-protein interactions on cushioned bilayers

    NASA Astrophysics Data System (ADS)

    Ghosh, S. K.; Mukhopadhyay, M. K.; Ma, Y.; Lopez, I.; Bera, S.; Lurio, L. B.; Chakrabarti, A.; Kim, J. E.; Sanyal, M. K.; Sinha, S. K.

    2013-03-01

    Biological membranes are heterogeneous and dynamical organizations of lipids and proteins, which perform functions fundamental to cell survival. Lipid-protein interactions control these functions by influencing folding and stability of integral or peripheral membrane proteins. Further, the incorporation or adsorption of these proteins into the membrane can in turn influence the lipid bilayer properties. In spite of some progress in understanding this process, a detailed structural analysis is lacking. Towards a better understanding of this interaction, we have performed an advanced interface sensitive scattering experiment using synchrotron x-rays. To accurately mimic the biological membranes with their natural thermal fluctuations and in-plane mobility of lipid molecules, polymer cushioned lipid bilayers have been used. This study shows that the adsorption of peripheral membrane proteinspectrindepends on the lipid headgroups, exhibiting different types of binding to phosphatidylcholine (PC) and phosphatidylethanolamie (PE). Further, the interaction of outer membrane protein A (OMP-A), an integral membrane protein is sensitive to the thermodynamic phase of the lipids. A detailed physical modeling of the lipid-protein interactions is under way.

  5. An evaluation of a novel alternating mattress and cushion technology.

    PubMed

    Chamanga, Edwin; Butcher, Ann

    2016-03-01

    Pressure ulcer prevention and management remain a challenge across all health-care settings, and the incidence and prevalence of pressure ulcers in nursing homes and residential homes continues to remain unknown. The use of suitable support surfaces has been found to be beneficial in the prevention and management of pressure ulcers. Carrying out a holistic assessment of the patient and recording the patient's at-risk score would help the clinician to determine the most suitable pressure-relieving surface for the patient. The clinician's clinical experience and judgment are also important. The Domus Auto (by APEX) mattress system and Dynamic Seat Cushion (by APEX) are effective dynamic, support surfaces in the prevention and management of pressure ulceration. They meet the recommendations by both national and international guidelines; they also partly fulfil the SSKIN bundle. From a four-week evaluation carried out in a nursing home, it has been demonstrated that, together with regular assessments and repositioning of the patients, these devices are useful tools in preventing patients' risk of tissue damage and improving the patients' quality of life. PMID:26940731

  6. Air

    MedlinePLUS

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  7. Comparison of the SCAQS tunnel study with other on-road vehicle emission data. [Southern California Air Quality Study (SCAQS)

    SciTech Connect

    Pierson, W.R.; Gertler, A.W. ); Bradow, R.L.

    1990-11-01

    The Van Nuys Tunnel experiment conducted in 1987 by Ingalls et al. (see A and WMA Paper 89-137.3), to verify automotive emission inventories as part of the Southern California Air Quality Study (SCAQS), gave higher Co and HC emission-rate values than expected on the basis of automotive-emission models - by factors of approximately 3 and 4, respectively. The CO/NO{sub x} and HC/NO{sub x} emission-rate ratios moreover were higher than expected - by similar factors (NO{sub x} emission rates were about as expected). The purpose of the present paper is to review the literature on dynamometer and on-road (in tunnels and along roadways) testing of in-use vehicles, and on urban-air CO/HC/NO{sub x} concentration ratios, to see whether the Van Nuys Tunnel results are reasonable in terms of previous experience. The conclusions are that (1) on-road CO and HC emissions higher than expected have been reported before, (2) on-road CO and HC emissions consistent with the Van Nuys Tunnel results have been reported before, and (3) on-road CO/NO{sub x} and HC/NO{sub x} emission-rate ratios higher than expected have been reported before. The Van Nuys Tunnel NO{sub x} results actually are lower than in other on-road experiments, and the CO/NO{sub x} and HC/NO{sub x} ratios consequently are higher. The higher-than-predicted CO/NO{sub x} and HC/NO{sub x} ratios at Van Nuys and other on-road sites suggest richer operation on-road than predicted or than observed in the in-use-vehicle dynamometer tests which serve as the model inputs. Support for these suggestions and conclusions is found in comparison of urban-air and emission-inventory HC/NO{sub x} ratios.

  8. A Feasibility Study on the Control of a Generic Air Vehicle Using Control Moment Gyros

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.

    2006-01-01

    This paper examines feasibility and performance issues in using Control Moment Gyroscopes (CMGs) to control the attitude of a fixed-wing aircraft. The paper describes a control system structure that permits allocating control authority and bandwidth between a CMG system and conventional aerodynamic control surfaces to stabilize a vehicle with neutral aerodynamic stability. A simulation study explores the interplay between aerodynamic and CMG effects, and indicates desirable physical characteristics for a CMG system to be used for aircraft attitude control.

  9. Net air emissions from electric vehicles: the effect of carbon price and charging strategies.

    PubMed

    Peterson, Scott B; Whitacre, J F; Apt, Jay

    2011-03-01

    Plug-in hybrid electric vehicles (PHEVs) may become part of the transportation fleet on time scales of a decade or two. We calculate the electric grid load increase and emissions due to vehicle battery charging in PJM and NYISO with the current generation mix, the current mix with a $50/tonne CO(2) price, and this case but with existing coal generators retrofitted with 80% CO(2) capture. We also examine all new generation being natural gas or wind+gas. PHEV fleet percentages between 0.4 and 50% are examined. Vehicles with small (4 kWh) and large (16 kWh) batteries are modeled with driving patterns from the National Household Transportation Survey. Three charging strategies and three scenarios for future electric generation are considered. When compared to 2020 CAFE standards, net CO(2) emissions in New York are reduced by switching from gasoline to electricity; coal-heavy PJM shows somewhat smaller benefits unless coal units are fitted with CCS or replaced with lower CO(2) generation. NO(X) is reduced in both RTOs, but there is upward pressure on SO(2) emissions or allowance prices under a cap. PMID:21309508

  10. An air launched, highly responsive military transatmospheric vehicle (TAV), based on existing aerospace systems

    NASA Astrophysics Data System (ADS)

    Hampsten, Kenneth R.

    1996-03-01

    A novel vehicle design is presented that minimizes Research Development Test and Evaluation (RDT&E) cost. The proposed TAV can satisfy a broad range of military mission applications for the 21st century. TAV deployment is provided by a Rockwell B-1B bomber. Pre-launch orientation of the vehicle is centerline, underneath the B-1B forward weapon bays. Launch occurs at 30,000 ft, Mach 0.90, and at a flight path angle of 15-20 degrees. The TAV is a Two-Stage-To-Orbit (TSTO) vehicle utilizing Liquid Oxygen (LOX) and RP-1 (kerosene) propellants. The reusable upper stage, or TAV, incorporates a 130 cubic foot payload bay for mission specific equipment. The booster can either be expended, or potentially recovered for reuse. TAV reentry relies on a biconic aeroshell for the hypersonic flight phase and a parafoil for the subsonic, terminal recovery phase. Nominal mission performance is between 1,150-1,800 lbs of payload into a 100 nmi circular orbit.

  11. Fundamental understanding of the cycloidal-rotor concept for micro air vehicle applications

    NASA Astrophysics Data System (ADS)

    Moble, Benedict

    The cycloidal-rotor (cyclorotor) is a revolutionary flying concept which has not been systematically studied in the past. Therefore, in the current research, the viability of the cyclorotor concept for powering a hover-capable micro-air-vehicle (MAV) was examined through both experiments and analysis. Experimental study included both performance and flow field measurements on a cyclorotor of span and diameter equal to 6 inches. The analysis developed was an unsteady large deformation aeroelastic analysis to predict the blade loads and average aerodynamic performance of the cyclorotor. The flightworthiness of the cyclorotor concept was also demonstrated through two cyclocopters capable of tethered hover. Systematic performance measurements have been conducted to understand the effect of the rotational speed, blade airfoil profile, blade flexibility, blade pitching amplitude (symmetric and asymmetric blade pitching), pitching axis location, number of blades with constant chord (varying solidity), and number of blades at same rotor solidity (varying blade chord) on the aerodynamic performance of the cyclorotor. Force measurements showed the presence of a significant sideward force on the cyclorotor (along with the vertical force), analogous to that found on a spinning circular cylinder. Particle image velocimetry (PIV) measurements made in the wake of the cyclorotor provided evidence of a significant wake skewness, which was produced by the sideward force. PIV measurements also captured the blade tip vortices and a large region of rotational flow inside the rotor. The thrust produced by the cyclorotor was found to increase until a blade pitch amplitude of 45° was reached without showing any signs of blade stall. This behavior was also explained using the PIV measurements, which indicated evidence of a stall delay as well as possible increase in lift on the blades from the presence of a leading edge vortex. Higher blade pitch amplitudes also improved the power loading (thrust/power) of the cyclorotor. When compared to the flat-plate blades, the NACA 0010 blades produced the highest values of thrust at all blade pitching amplitudes. The NACA blades also produced higher power loading than the flat plate blades. However, the reverse NACA 0010 blades produced better power loadings at lower pitching amplitudes, even though at high pitch amplitudes, regular NACA blades performed better. Among the three NACA sections (NACA 0006, NACA 0010 and NACA 0015) tested on the cyclorotor, NACA 0015 had the highest power loading followed by NACA 0010 and then NACA 0006. The power loading also increased when using more blades with constant chord (increasing solidity); this observation was found over a wide range of blade pitching amplitudes. Asymmetric pitching with higher pitch angle at the top of the blade trajectory than at the bottom produced better power loading. The chordwise op timum pitching axis location was approximately 25--35% of the blade chord. For a constant solidity, the rotor with fewer number of blades produced higher thrust and the 2-bladed rotor had the best power loading. Any significant bending and torsional flexibility of the blades had a deleterious effect on performance. The optimized cyclorotor had slightly higher power loading when compared to a conventional micro-rotor when operated at the same disk loading. The optimum configuration based on all the tests was a 4-bladed rotor using 1.3 inch chord NACA 0015 blade section with an asymmetric pitching of 45° at top and 25° at bottom with the pitching axis at 25% chord. The aeroelastic analysis was performed using two approaches, one using a second-order non-linear beam FEM analysis for moderately flexible blades and second using a multibody based large-deformation analysis (especially applicable for extremely flexible blades) incorporating a geometrically exact beam model. An unsteady aerodynamic model is included in the analysis with two different inflow models, single streamtube and a double-multiple streamtube inflow model. For the cycloidal rotors using moderately flexible blades, the aeroelastic analysis was able to predict the average thrust with sufficient accuracy over a wide range of rotational speeds, pitching amplitudes and number of blades. However, for the extremely flexible blades, the thrust was underpredicted at higher rotational speeds and this may be because of the overprediction of blade deformations. The inclusion of the actual blade pitch kinematics and unsteady aerodynamics was found crucial in the accurate sideward force prediction.

  12. Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

    PubMed Central

    2014-01-01

    Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions. PMID:24621126

  13. Some factors affecting the use of lighter than air systems. [economic and performance estimates for dirigibles and semi-buoyant hybrid vehicles

    NASA Technical Reports Server (NTRS)

    Havill, C. D.

    1974-01-01

    The uses of lighter-than-air vehicles are examined in the present day transportation environment. Conventional dirigibles were found to indicate an undesirable economic risk due to their low speeds and to uncertainties concerning their operational use. Semi-buoyant hybrid vehicles are suggested as an alternative which does not have many of the inferior characteristics of conventional dirigibles. Economic and performance estimates for hybrid vehicles indicate that they are competitive with other transportation systems in many applications, and unique in their ability to perform some highly desirable emergency missions.

  14. Ride quality improvement ability of semi-active, active, and passive suspension systems for railway vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Dai-Hua; Liao, Wei-Hsin

    2003-08-01

    It is one of effective ways to increase the running speed of railway vehicles to make the railways more competitive with air transport while providing better safety. However, the high speed of the train would cause significant car body vibrations, which induce the following problems: the ride stability, the ride quality, and the cost of track maintenance. Thus various kinds of railway vehicle suspensions, which can be categorized as passive, active, and semi-active types, have been designed to cushion riders from vibrations. In this paper, it is aimed to investigate semi-active suspension systems using magnetorheological (MR) fluid dampers for improving the ride quality of railway vehicles. A full-scale railway vehicle model with seventeen degrees of freedom is proposed to cope with lateral, yaw and roll motions of the car body, trucks and wheelsets. The governing equations of the railway vehicle integrated with MR fluid dampers in the secondary suspension are developed and the LQG control law using the acceleration feedback is adopted, in which the state variables are estimated from the measurable accelerations with the Kalman estimator. The performance of the semi-active suspension system exploiting MR fluid dampers is compared with those of the active suspension system with linear and unconstraint actuators and the passive suspension system with springs and oil dampers. The results show that the semi-active suspension system with MR fluid dampers possesses a good ride quality improvement ability.

  15. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, Boyu; Wu, Lin; Mao, Hongjun; Gong, Sunning; He, Jianjun; Zou, Chao; Song, Guohua; Li, Xiaoyu; Wu, Zhong

    2016-03-01

    This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near-real-time traffic data on road segments to develop a vehicle emission inventory with high temporal-spatial resolution (HTSVE) for the Beijing urban area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Based on the results of this study, improved air quality simulation and the contribution of vehicle emissions to ambient pollutant concentration in Beijing have been investigated in a companion paper (He et al., 2016).

  16. Novel prescribed performance neural control of a flexible air-breathing hypersonic vehicle with unknown initial errors.

    PubMed

    Bu, Xiangwei; Wu, Xiaoyan; Zhu, Fujing; Huang, Jiaqi; Ma, Zhen; Zhang, Rui

    2015-11-01

    A novel prescribed performance neural controller with unknown initial errors is addressed for the longitudinal dynamic model of a flexible air-breathing hypersonic vehicle (FAHV) subject to parametric uncertainties. Different from traditional prescribed performance control (PPC) requiring that the initial errors have to be known accurately, this paper investigates the tracking control without accurate initial errors via exploiting a new performance function. A combined neural back-stepping and minimal learning parameter (MLP) technology is employed for exploring a prescribed performance controller that provides robust tracking of velocity and altitude reference trajectories. The highlight is that the transient performance of velocity and altitude tracking errors is satisfactory and the computational load of neural approximation is low. Finally, numerical simulation results from a nonlinear FAHV model demonstrate the efficacy of the proposed strategy. PMID:26456727

  17. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... develop unique or complicated braking systems to comply with these requirements. \\9\\ See 74 FR 37152-53.... 121, Air Brake Systems, to require improved stopping distance performance for heavy truck tractors.\\1... distance requirements on in-service braking performance set by the Federal Motor Carrier...

  18. Experimental Investigation of Project Orion Crew Exploration Vehicle Aeroheating: LaRC 20-Inch Mach 6 Air Tunnel Test 6931

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.

    2009-01-01

    An investigation of the aeroheating environment of the Project Orion Crew Entry Vehicle has been performed in the Langley Research Center 20-Inch Mach 6 Air Tunnel. Data were measured on a approx.3.5% scale model (0.1778-m/7-inch diameter) of the vehicle using coaxial thermocouples at free stream Reynolds numbers of 2.0 10(exp 6)/ft to 7.30 10(exp 6)/ft and computational predictions were generated for all test conditions. The primary goals of this test were to obtain convective heating data for use in assessing the accuracy of the computational technique and to validate test methodology and heating data from a test of the same wind tunnel model in the Arnold Engineering Development Center Tunnel 9. Secondary goals were to determine the extent of transitional/turbulent data which could be produced on a CEV model in this facility, either with or without boundary-layer trips, and to demonstrate continuous pitch-sweep operation in this tunnel for heat transfer testing.

  19. Micro air vehicle-motivated computational biomechanics in bio-flights: aerodynamics, flight dynamics and maneuvering stability

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Nakata, Toshiyuki; Gao, Na; Maeda, Masateru; Aono, Hikaru; Shyy, Wei

    2010-12-01

    Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles (MAVs) design, we propose a comprehensive computational framework, which integrates aerodynamics, flight dynamics, vehicle stability and maneuverability. This framework consists of (1) a Navier-Stokes unsteady aerodynamic model; (2) a linear finite element model for structural dynamics; (3) a fluid-structure interaction (FSI) model for coupled flexible wing aerodynamics aeroelasticity; (4) a free-flying rigid body dynamic (RBD) model utilizing the Newtonian-Euler equations of 6DoF motion; and (5) flight simulator accounting for realistic wing-body morphology, flapping-wing and body kinematics, and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight. Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly. The present approach can support systematic analyses of bio- and bio-inspired flight.

  20. Novel adaptive neural control design for a constrained flexible air-breathing hypersonic vehicle based on actuator compensation

    NASA Astrophysics Data System (ADS)

    Bu, Xiangwei; Wu, Xiaoyan; He, Guangjun; Huang, Jiaqi

    2016-03-01

    This paper investigates the design of a novel adaptive neural controller for the longitudinal dynamics of a flexible air-breathing hypersonic vehicle with control input constraints. To reduce the complexity of controller design, the vehicle dynamics is decomposed into the velocity subsystem and the altitude subsystem, respectively. For each subsystem, only one neural network is utilized to approach the lumped unknown function. By employing a minimal-learning parameter method to estimate the norm of ideal weight vectors rather than their elements, there are only two adaptive parameters required for neural approximation. Thus, the computational burden is lower than the ones derived from neural back-stepping schemes. Specially, to deal with the control input constraints, additional systems are exploited to compensate the actuators. Lyapunov synthesis proves that all the closed-loop signals involved are uniformly ultimately bounded. Finally, simulation results show that the adopted compensation scheme can tackle actuator constraint effectively and moreover velocity and altitude can stably track their reference trajectories even when the physical limitations on control inputs are in effect.

  1. Prediction of thermal behaviors of an air-cooled lithium-ion battery system for hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Choi, Yong Seok; Kang, Dal Mo

    2014-12-01

    Thermal management has been one of the major issues in developing a lithium-ion (Li-ion) hybrid electric vehicle (HEV) battery system since the Li-ion battery is vulnerable to excessive heat load under abnormal or severe operational conditions. In this work, in order to design a suitable thermal management system, a simple modeling methodology describing thermal behavior of an air-cooled Li-ion battery system was proposed from vehicle components designer's point of view. A proposed mathematical model was constructed based on the battery's electrical and mechanical properties. Also, validation test results for the Li-ion battery system were presented. A pulse current duty and an adjusted US06 current cycle for a two-mode HEV system were used to validate the accuracy of the model prediction. Results showed that the present model can give good estimations for simulating convective heat transfer cooling during battery operation. The developed thermal model is useful in structuring the flow system and determining the appropriate cooling capacity for a specified design prerequisite of the battery system.

  2. Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs)

    NASA Astrophysics Data System (ADS)

    Hatfield, M. C.; Webley, P.; Saiet, E., II

    2014-12-01

    Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs) Numerous scientific and logistical applications exist in Alaska and other arctic regions requiring analysis of expansive, remote areas in the near infrared (NIR) and thermal infrared (TIR) bands. These include characterization of wild land fire plumes and volcanic ejecta, detailed mapping of lava flows, and inspection of lengthy segments of critical infrastructure, such as the Alaska pipeline and railroad system. Obtaining timely, repeatable, calibrated measurements of these extensive features and infrastructure networks requires localized, taskable assets such as UAVs. The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) provides practical solutions to these problem sets by pairing various IR sensors with a combination of fixed-wing and multi-rotor air vehicles. Fixed-wing assets, such as the Insitu ScanEagle, offer long reach and extended duration capabilities to quickly access remote locations and provide enduring surveillance of the target of interest. Rotary-wing assets, such as the Aeryon Scout or the ACUASI-built Ptarmigan hexcopter, provide a precision capability for detailed horizontal mapping or vertical stratification of atmospheric phenomena. When included with other ground capabilities, we will show how they can assist in decision support and hazard assessment as well as giving those in emergency management a new ability to increase knowledge of the event at hand while reducing the risk to all involved. Here, in this presentation, we illustrate how UAV's can provide the ideal tool to map and analyze the hazardous events and critical infrastructure under extreme environmental conditions.

  3. A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System

    NASA Technical Reports Server (NTRS)

    VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

    2008-01-01

    Suborbital space flight and space tourism are new potential markets that could significantly impact the National Airspace System (NAS). Numerous private companies are developing space flight capabilities to capture a piece of an emerging commercial space transportation market. These entrepreneurs share a common vision that sees commercial space flight as a profitable venture. Additionally, U.S. space exploration policy and national defense will impose significant additional demands on the NAS. Air traffic service providers must allow all users fair access to limited airspace, while ensuring that the highest levels of safety, security, and efficiency are maintained. The FAA's Next Generation Air Transportation System (NextGen) will need to accommodate spacecraft transitioning to and from space through the NAS. To accomplish this, space and air traffic operations will need to be seamlessly integrated under some common communications, navigation and surveillance (CNS) infrastructure. As part of NextGen, the FAA has been developing the Automatic Dependent Surveillance Broadcast (ADS-B) which utilizes the Global Positioning System (GPS) to track and separate aircraft. Another key component of NextGen, System-Wide Information Management/ Network Enabled Operations (SWIM/NEO), is an open architecture network that will provide NAS data to various customers, system tools and applications. NASA and DoD are currently developing a space-based range (SBR) concept that also utilizes GPS, communications satellites and other CNS assets. The future SBR will have very similar utility for space operations as ADS-B and SWIM has for air traffic. Perhaps the FAA, NASA, and DoD should consider developing a common space-based CNS infrastructure to support both aviation and space transportation operations. This paper suggests specific areas of research for developing a CNS infrastructure that can accommodate spacecraft and other new types of vehicles as an integrated part of NextGen.

  4. Novel operation and control of an electric vehicle aluminum/air battery system

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Yang, Shao Hua; Knickle, Harold

    The objective of this paper is to create a method to size battery subsystems for an electric vehicle to optimize battery performance. Optimization of performance includes minimizing corrosion by operating at a constant current density. These subsystems will allow for easy mechanical recharging. A proper choice of battery subsystem will allow for longer battery life, greater range and performance. For longer life, the current density and reaction rate should be nearly constant. The control method requires control of power by controlling electrolyte flow in battery sub modules. As power is increased more sub modules come on line and more electrolyte is needed. Solenoid valves open in a sequence to provide the required power. Corrosion is limited because there is no electrolyte in the modules not being used.

  5. Numerical Simulation and Experiment on Supersonic Air-Breathing Laser-Spike Propulsion Vehicle

    NASA Astrophysics Data System (ADS)

    Kim, Sukyum; Kim, Young-Taek; Jeung, In-Seuck

    2005-04-01

    As a kind of application of laser propulsion, air-breathing laser-spike engine can be designed for aircraft in atmospheric flight. Laser-spike engine generates thrust using the blast wave induced by laser energy instead of combustion process. This engine uses air as propellant, therefore, it needs no on-board propellant. For experimental study, a blow-down type supersonic wind tunnel and spark generator were used. Supersonic wind tunnel blows Mach number 2.5 supersonic flow and a spark generator was used as energy source in place of laser. Flow visualization was performed for 2-dimensional laser-spike engine model and numerical simulation of the corresponding case for the experiment was done and compared with experimental case.

  6. Air pollutant emissions from on-road vehicles in China, 1999-2011.

    PubMed

    Lang, Jianlei; Cheng, Shuiyuan; Zhou, Ying; Zhang, Yonglin; Wang, Gang

    2014-10-15

    The on-road vehicular emission in China from 1999 to 2011 was estimated, based on the emission factors of vehicles with different emission standards calculated by the COPERT model. The CO, NMVOC, NOX, BC and OC emissions changed from 19.7 Tg, 4.4 Tg, 2.3 Tg, 47.1 Gg and 74.4 Gg in 1999 to 32.7 Tg, 4.1 Tg, 7.6 Tg, 177.6 Gg and 101.5 Gg in 2011, respectively. The general trend for CO, NOX and BC was increasing, while the tendency for NMVOC and OC was firstly increase before 2002 and then decrease from 2003. The spatial analysis results showed that high emissions occurred in developed provinces (Guangdong, Shandong, Hebei, Jiangsu and Henan). The correlation between vehicular emissions and GDP were further investigated and good linear correlation was found. The not-obvious change of the inter-annual (1999-2011) fitted straight line slope and the sustained increasing emissions for NOX and BC suggested that the challenge of mitigating vehicular NOX and BC emissions is severe in China. The contribution from different vehicle types was also analyzed. Passenger car (PC) and motorcycle (MC) was the main contributor to the CO and NMVOC emissions. However, the contribution ratio of MC was decreasing from 36.6% and 68.8% in 1999 to 15.7% and 25.7% in 2011. Heavy duty truck (HDT) was the dominant contributor to NOX, BC and OC, with proportions of 58.9%, 57.6% and 52.8% in 2011, respectively. In addition, the uncertainty of the estimated emissions was also assessed based on the Monte Carlo simulation. PMID:25051424

  7. Design and development of an unconventional VTOL micro air vehicle: The Cyclocopter

    NASA Astrophysics Data System (ADS)

    Benedict, Moble; Chopra, Inderjit

    2012-06-01

    This paper discusses the systematic experimental and vehicle design/development studies conducted at the University of Maryland which culminated in the development of the first flying Cyclocopter in the history. Cyclocopter is a novel Vertical Take-Off and Landing (VTOL) aircraft, which utilizes cycloidalrotors (cyclorotors), a revolutionary horizontal axis propulsion concept, that has many advantages such as higher aerodynamic efficiency, maneuverability and high-speed forward flight capability when compared to a conventional helicopter rotor. The experimental studies included a detailed parametric study to understand the effect of rotor geometry and blade kinematics on cyclorotor hover performance. Based on the experimental results, higher blade pitch angles were found to improve thrust and increase the power loading (thrust per unit power) of the cyclorotor. Asymmetric pitching with higher pitch angle at the top than at the bottom produced better power loading. The chordwise optimum pitching axis location was observed to be around 25-35% of the blade chord. Because of the flow curvature effects, the cycloidal rotor performance was a strong function of the chord/radius ratio. The optimum chord/radius ratios were extremely high, around 0.5-0.8, depending on the blade pitching amplitude. A flow field investigation was also conducted using Particle Image Velocimetry (PIV) to unravel the physics behind thrust production of a cyclorotor. PIV studies indicated evidence of a stall delay as well as possible increases in lift on the blades from the presence of a leading edge vortex. The goal of all these studies was to understand and optimize the performance of a micro-scale cyclorotor so that it could be used in a flying vehicle. An optimized cyclorotor was used to develop a 200 gram cyclocopter capable of autonomous stable hover using an onboard feedback controller.

  8. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta.

    PubMed

    Kleier, Catherine; Trenary, Tim; Graham, Eric A; Stenzel, William; Rundel, Philip W

    2015-01-01

    Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr(-1). Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20 from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant. PMID:25802811

  9. Examples of the application of the cause-effect ergonomic evaluation model to the wheelchair cushions.

    PubMed

    Barber-Guillem, Ricard; Page, lvaro; Laparra, Jos; Dur, Juan V

    2015-01-01

    This article highlights the potential of the application of the cause-effect model for the ergonomic evaluation in the field of cushions. User involvement in the prescription and development of assistive devices have been identified a key aspect for positive interventions, although the reality is that we lack of systematic approaches and examples of best practices. The potential benefits are identified for the development of new products and in the prescription process. Additional research would be necessary to better link the characteristics of the cushions and users with the biomechanical and physiological performance of the interface cushion-user and the consequences measured in health, user perception and activity performance. This article shows examples of the relationship in this three levels from the point of view of the user perception. PMID:26294494

  10. Size class structure, growth rates, and orientation of the central Andean cushion Azorella compacta

    PubMed Central

    Trenary, Tim; Graham, Eric A.; Stenzel, William; Rundel, Philip W.

    2015-01-01

    Azorella compacta (llareta; Apiaceae) forms dense, woody, cushions and characterizes the high elevation rocky slopes of the central Andean Altiplano. Field studies of an elevational gradient of A. compacta within Lauca National Park in northern Chile found a reverse J-shape distribution of size classes of individuals with abundant small plants at all elevations. A new elevational limit for A. compacta was established at 5,250 m. A series of cushions marked 14 years earlier showed either slight shrinkage or small degrees of growth up to 2.2 cm yr?1. Despite their irregularity in growth, cushions of A. compacta show a strong orientation, centered on a north-facing aspect and angle of about 20 from horizontal. This exposure to maximize solar irradiance closely matches previous observations of a population favoring north-facing slopes at a similar angle. Populations of A. compacta appear to be stable, or even expanding, with young plants abundant. PMID:25802811

  11. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle

    PubMed Central

    Chan, Woei-Leong; Hsiao, Fei-Bin

    2011-01-01

    This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly. PMID:22163819

  12. Criteria and air-toxic emissions from in-use automobiles in the National Low-Emission Vehicle program.

    PubMed

    Baldauf, Rich W; Gabele, Pete; Crews, William; Snow, Richard; Cook, J Rich

    2005-09-01

    The U.S. Environmental Protection Agency (EPA) implemented a program to identify tailpipe emissions of criteria and air-toxic contaminants from in-use, light-duty low-emission vehicles (LEVs). EPA recruited 25 LEVs in 2002 and measured emissions on a chassis dynamometer using the cold-start urban dynamometer driving schedule of the Federal Test Procedure. The emissions measured included regulated pollutants, particulate matter, speciated hydrocarbon compounds, and carbonyl compounds. The results provided a comparison of emissions from real-world LEVs with emission standards for criteria and air-toxic compounds. Emission measurements indicated that a portion of the in-use fleet tested exceeded standards for the criteria gases. Real-time regulated and speciated hydrocarbon measurements demonstrated that the majority of emissions occurred during the initial phases of the cold-start portion of the urban dynamometer driving schedule. Overall, the study provided updated emission factor data for real-world, in-use operation of LEVs for improved emissions modeling and mobile source inventory development. PMID:16259421

  13. Implementation of the Rauch-Tung-Striebel smoother for sensor compatibility correction of a fixed-wing unmanned air vehicle.

    PubMed

    Chan, Woei-Leong; Hsiao, Fei-Bin

    2011-01-01

    This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly. PMID:22163819

  14. The plantar cushion reflex circuit: an oligosynaptic cutaneous reflex

    PubMed Central

    Egger, M. David; Wall, Patrick D.

    1971-01-01

    1. Reflex toe extension elicited by pressure on the plantar cushion (PC) was studied in cats anaesthetized with Dial. Receptive fields and adequate stimuli for the reflex were evaluated. It was concluded that the receptors for the reflex were chiefly cutaneous pressure receptors in PC. 2. The fastest impulses from the PC receptors for this reflex are conducted to the spinal cord at about 64 m/sec via fibres about 10-11 ?m in diameter, i.e. the largest afferent fibres from PC. The motoneurones active in the reflex mainly supplied the intrinsic plantar muscles. Most active axons ran in the S1 ventral root. 3. Extracellular recordings of interneurones in the dorsal horn of L7 spinal segment revealed that many units at the medial edge of the dorsal horn, chiefly in Rexed's laminae IV and V, were activated by stimuli similar to those eliciting the PCtoe extension reflex. These were termed intermediate threshold PC units. Some of these medially located units were activated monosynaptically by PC stimulation. Intermediate threshold PC units activated disynaptically or polysynaptically were also found in this medial region of the dorsal horn, as well as ventrolaterally and caudally in lamina V. 4. No intermediate threshold PC units sent axons into dorsolateral ipsilateral thoracic white matter, in contrast to lower threshold PC units, 42% of which were driven by lateral column stimulation. 5. Extracellular and intracellular recordings were made from motoneurones activated by adequate stimuli for the reflex. Minimum latencies of EPSPs revealed that, for the fastest component of the reflex, at most two interneurones could be interposed between a primary sensory neurone and a motoneurone. 6. Although convergence of low threshold PC units on to intermediate threshold PC units or on to motoneurones may play a part in the PCtoe extension reflex, it appears probable that the two populations of intermediate threshold PC interneurones described above, that is, the monosynaptic and the disynaptic (with higher order interneurones), mediate the reflex. PMID:5559630

  15. Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009

    PubMed Central

    Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

    2014-01-01

    On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs) during 19952009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NOx, and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 19952009 period despite an increase in total vehicle distance traveled. The CO and NOx emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NOx in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001 2009. Although this trend coexists with the declining trends in on-road NOx, VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NOx in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NOx during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of the benefits of past control measures. PMID:25122954

  16. ISO 16840-2:2007 load deflection and hysteresis measurements for a sample of wheelchair seating cushions.

    PubMed

    Hollington, James; Hillman, Susan J; Torres-Sánchez, Carmen; Boeckx, Jens; Crossan, Neil

    2014-04-01

    Load deflection and hysteresis measurements were made on 37 wheelchair seating cushions according to ISO 16840-2:2007. Load deflection plots for all 37 cushions are reported and fundamental aspects of graph interpretation discussed. ISO hysteresis data are also reported and interpretation discussed. PMID:24230981

  17. Association of digital cushion thickness with sole temperature measured with the use of infrared thermography.

    PubMed

    Oikonomou, G; Trojacanec, P; Ganda, E K; Bicalho, M L S; Bicalho, R C

    2014-07-01

    The main objective of this study was to investigate the association between digital cushion thickness and sole temperature measured by infrared thermography. Data were collected from 216 lactating Holstein cows at 4 to 10d in milk (DIM). Cows were locomotion scored and sole temperature was measured after claw trimming (a minimum delay of 3 min was allowed for the hoof to cool) using an infrared thermography camera. Temperature was measured at the typical ulcer site of the lateral digit of the left hind foot. Immediately after the thermographic image was obtained, the thickness of the digital cushion was measured by ultrasonography. Rumen fluid samples were collected with a stomach tube and sample pH was measured immediately after collection. Additionally, a blood sample was obtained and used for measurements of serum concentrations of β-hydroxybutyrate (BHBA), nonesterified fatty acids (NEFA), and haptoglobin. To evaluate the associations of digital cushion thickness with sole temperature, a linear regression model was built using the GLIMMIX procedure in SAS software (SAS Institute Inc., Cary, NC). Sole temperature was the response variable, and digital cushion thickness quartiles, locomotion score group, rumen fluid pH, rumen fluid sample volume, environmental temperature, age in days, and serum levels of NEFA, BHBA, and haptoglobin were fitted in the model. Only significant variables were retained in the final model. Simple linear regression scatter plots were used to illustrate associations between sole temperature (measured by infrared thermography at the typical ulcer site) and environmental temperature and between NEFA and BHBA serum levels and haptoglobin. One-way ANOVA was used to compare rumen fluid pH for different locomotion score groups and for different digital cushion quartiles. Results from the multivariable linear regression model showed that sole temperature increased as locomotion scores increased and decreased as digital cushion thickness increased. These results were adjusted for environmental temperature, which was significantly associated with sole temperature. Serum levels of NEFA, BHBA, and haptoglobin were not associated with sole temperature. However, significant correlations existed between serum levels of NEFA and haptoglobin and between serum levels of BHBA and haptoglobin. Rumen fluid pH was not associated with either locomotion score or digital cushion thickness. In conclusion, we show here that digital cushion thickness was associated with sole temperature in cows at 4 to 10 DIM. PMID:24835964

  18. KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development

    SciTech Connect

    J. W. Schneider

    2009-10-01

    The S-5370 RTV blown foam previously produced by Dow Corning is no longer commercially available. The S-5370 material has been used on all of Los Alamos National Laboratory (LANL) programs to manufacture Stress Cushions up through the W88. The Kansas City Plant (KCP) did not have a sufficient supply of S-5370 material to cover the schedule requirements for the Program. This report provides information on the numerous activities conducted at KCP involving the development of the Program Stress Cushion and replacement RTV material.

  19. Unmanned air vehicle flow separation control using dielectric barrier discharge plasma at high wind speed

    NASA Astrophysics Data System (ADS)

    Zhang, Xin; Huang, Yong; Wang, WanBo; Wang, XunNian; Li, HuaXing

    2014-06-01

    The present paper described an experimental investigation of separation control of an Unmanned Aerial Vehicle (UAV) at high wind speeds. The plasma actuator was based on Dielectric Barrier Discharge (DBD) and operated in a steady manner. The flow over a wing of UAV was performed with smoke flow visualization in the ?0.75 m low speed wind tunnel to reveal the flow structure over the wing so that the locations of plasma actuators could be optimized. A full model of the UAV was experimentally investigated in the ?3.2 m low speed wind tunnel using a six-component internal strain gauge balance. The effects of the key parameters, including the locations of the plasma actuators, the applied voltage amplitude and the operating frequency, were obtained. The whole test model was made of aluminium and acted as a cathode of the actuator. The results showed that the plasma acting on the surface of UAV could obviously suppress the boundary layer separation and reduce the model vibration at the high wind speeds. It was found that the maximum lift coefficient of the UAV was increased by 2.5% and the lift/drag ratio was increased by about 80% at the wind speed of 100 m/s. The control mechanism of the plasma actuator at the test configuration was also analyzed.

  20. A multimodal micro air vehicle for autonomous flight in near-earth environments

    NASA Astrophysics Data System (ADS)

    Green, William Edward

    Reconnaissance, surveillance, and search-and-rescue missions in near-Earth environments such as caves, forests, and urban areas pose many new challenges to command and control (C2) teams. Of great significance is how to acquire situational awareness when access to the scene is blocked by enemy fire, rubble, or other occlusions. Small bird-sized aerial robots are expendable and can fly over obstacles and through small openings to assist in the acquisition and distribution of intelligence. However, limited flying space and densely populated obstacle fields requires a vehicle that is capable of hovering, but also maneuverable. A secondary flight mode was incorporated into a fixed-wing aircraft to preserve its maneuverability while adding the capability of hovering. An inertial measurement sensor and onboard flight control system were interfaced and used to transition the hybrid prototype from cruise to hover flight and sustain a hover autonomously. Furthermore, the hovering flight mode can be used to maneuver the aircraft through small openings such as doorways. An ultrasonic and infrared sensor suite was designed to follow exterior building walls until an ingress route was detected. Reactive control was then used to traverse the doorway and gather reconnaissance. Entering a dangerous environment to gather intelligence autonomously will provide an invaluable resource to any C2 team. The holistic approach of platform development, sensor suite design, and control serves as the philosophy of this work.

  1. Verification and Tuning of an Adaptive Controller for an Unmanned Air Vehicle

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

    2010-01-01

    This paper focuses on the analysis and tuning of a controller based on the Adaptive Control Technology for Safe Flight (ACTS) architecture. The ACTS architecture consists of a nominal, non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off-nominal ones. A framework unifying control verification and gain tuning is used to make the controller s ability to satisfy the closed-loop requirements more robust to uncertainty. In this paper we tune the gains of both controllers using this approach. Some advantages and drawbacks of adaptation are identified by performing a global robustness assessment of both the adaptive controller and its non-adaptive counterpart. The analyses used to determine these characteristics are based on evaluating the degradation in closed-loop performance resulting from uncertainties having increasing levels of severity. The specific adverse conditions considered can be grouped into three categories: aerodynamic uncertainties, structural damage, and actuator failures. These failures include partial and total loss of control effectiveness, locked-in-place control surface deflections, and engine out conditions. The requirements considered are the peak structural loading, the ability of the controller to track pilot commands, the ability of the controller to keep the aircraft s state within the reliable flight envelope, and the handling/riding qualities of the aircraft. The nominal controller resulting from these tuning strategies was successfully validated using the NASA GTM Flight Test Vehicle.

  2. Inertial attitude control of a bat-like morphing-wing air vehicle.

    PubMed

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-03-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (?) and pitch (?) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms?. PMID:23211685

  3. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Astrophysics Data System (ADS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-06-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  4. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  5. Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.

    PubMed

    Lee, Eon S; Zhu, Yifang

    2014-02-18

    Modern passenger vehicles are commonly equipped with cabin air filters but their filtration efficiency for ultrafine particle (UFP) is rather low. Although setting the vehicle ventilation system to recirculation (RC) mode can reduce in-cabin UFPs by ∼ 90%, passenger-exhaled carbon dioxide (CO2) can quickly accumulate inside the cabin. Using outdoor air (OA) mode instead can provide sufficient air exchange to prevent CO2 buildup, but in-cabin UFP concentrations would increase. To overcome this dilemma, we developed a simultaneous mitigation method for UFP and CO2 using high-efficiency cabin air (HECA) filtration in OA mode. Concentrations of UFP and other air pollutants were simultaneously monitored in and out of 12 different vehicles under 3 driving conditions: stationary, on local roadways, and on freeways. Under each experimental condition, data were collected with no filter, in-use original equipment manufacturer (OEM) filter, and two types of HECA filters. The HECA filters offered an average in-cabin UFP reduction of 93%, much higher than the OEM filters (∼ 50% on average). Throughout the measurements, the in-cabin CO2 concentration remained in the range of 620-930 ppm, significantly lower than the typical level of 2500-4000 ppm observed in the RC mode. PMID:24471775

  6. Assessment of Charging Infrastructure for Plug-in Electric Vehicles at Naval Air Station Whidbey Island: Task 3

    SciTech Connect

    Schey, Steve; Francfort, Jim

    2015-07-01

    Several U.S. Department of Defense base studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 1 consisted of a survey of the non-tactical fleet of vehicles at NASWI to begin the review of vehicle mission assignments and types of vehicles in service. Task 2 selected vehicles for further monitoring and involved identifying daily operational characteristics of these select vehicles. Data logging of vehicle movements was initiated in order to characterize the vehicle’s mission. The Task 3 Vehicle Utilization report provided the results of the data analysis and observations related to the replacement of current vehicles with PEVs. This report provides an assessment of charging infrastructure required to support the suggested PEV replacements.

  7. Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle

    PubMed Central

    Zhang, G. Q.; Yu, S. C. M.

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  8. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    NASA Astrophysics Data System (ADS)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2) energy harvesting to extend operational time and autonomy, and (3) sensing of an aerodynamic force associated with wing deformation.

  9. Air toxics exposure from vehicle emissions at a U.S. border crossing: Buffalo Peace Bridge Study.

    PubMed

    Spengler, John; Lwebuga-Mukasa, Jamson; Vallarino, Jose; Melly, Steve; Chillrud, Steve; Baker, Joel; Minegishi, Taeko

    2011-07-01

    The Peace Bridge in Buffalo, New York, which spans the Niagara River at the east end of Lake Erie, is one of the busiest U.S. border crossings. The Peace Bridge plaza on the U.S. side is a complex of roads, customs inspection areas, passport control areas, and duty-free shops. On average 5000 heavy-duty diesel trucks and 20,000 passenger cars traverse the border daily, making the plaza area a potential "hot spot" for emissions from mobile sources. In a series of winter and summer field campaigns, we measured air pollutants, including many compounds considered by the U.S. Environmental Protection Agency (EPA*) as mobile-source air toxics (MSATs), at three fixed sampling sites: on the shore of Lake Erie, approximately 500 m upwind (under predominant wind conditions) of the Peace Bridge plaza; immediately downwind of (adjacent to) the plaza; and 500 m farther downwind, into the community of west Buffalo. Pollutants sampled were particulate matter (PM) < or = 10 microm (PM10) and < or = 2.5 microm (PM2.5) in aerodynamic diameter, elemental carbon (EC), 28 elements, 25 volatile organic compounds (VOCs) including 3 carbonyls, 52 polycyclic aromatic hydrocarbons (PAHs), and 29 nitrogenated polycyclic aromatic hydrocarbons (NPAHs). Spatial patterns of counts of ultrafine particles (UFPs, particles < 0.1 microm in aerodynamic diameter) and of particle-bound PAH (pPAH) concentrations were assessed by mobile monitoring in the neighborhood adjacent to the Peace Bridge plaza using portable instruments and Global Positioning System (GPS) tracking. The study was designed to assess differences in upwind and downwind concentrations of MSATs, in areas near the Peace Bridge plaza on the U.S. side of the border. The Buffalo Peace Bridge Study featured good access to monitoring locations proximate to the plaza and in the community, which are downwind with the dominant winds from the direction of Lake Erie and southern Ontario. Samples from the lakeside Great Lakes Center (GLC), which is upwind of the plaza with dominant winds, were used to characterize contaminants in regional air masses. On-site meteorologic measurements and hourly truck and car counts were used to assess the role of traffic on UFP counts and pPAH concentrations. The array of parallel and perpendicular residential streets adjacent to the plaza provided a grid on which to plot the spatial patterns of UFP counts and pPAH concentrations to determine the extent to which traffic emissions from the Peace Bridge plaza might extend into the neighboring community. For lake-wind conditions (southwest to northwest) 12-hour integrated daytime samples showed clear evidence that vehicle-related emissions at the Peace Bridge plaza were responsible for elevated downwind concentrations of PM2.5, EC, and benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as 1,3-butadiene and styrene. The chlorinated VOCs and aldehydes were not differentially higher at the downwind site. Several metals (aluminum, calcium, iron, copper, and antimony) were two times higher at the site adjacent to the plaza as they were at the upwind GLC site on lake-wind sampling days. Other metals (beryllium, sodium, magnesium, potassium, titanium, manganese, cobalt, strontium, tin, cesium, and lanthanum) showed significant increases downwind as well. Sulfur, arsenic, selenium, and a few other elements appeared to be markers for regional transport as their upwind and downwind concentrations were correlated, with ratios near unity. Using positive matrix factorization (PMF), we identified the sources for PAHs at the three fixed sampling sites as regional, diesel, general vehicle, and asphalt volatilization. Diesel exhaust at the Peace Bridge plaza accounted for approximately 30% of the PAHs. The NPAH sources were identified as nitrate (NO3) radical reactions, diesel, and mixed sources. Diesel exhaust at the Peace Bridge plaza accounted for 18% of the NPAHs. Further evidence for the impact of the Peace Bridge plaza on local air quality was found when the differences in 10-minute average UFP counts and pPAH concentrations were calculated between pairs of sites and displayed by wind direction. With winds from approximately 160 degrees through 220 degrees, UFP counts adjacent to the plaza were 10,000 to 20,000 particles/cm3 higher than those upwind of the plaza. A similar pattern was displayed for pPAH concentrations adjacent to the plaza, which were between 10 and 20 ng/m3 higher than those at the upwind GLC site. Regression models showed better correlation with traffic variables for pPAHs than for UFPs. For pPAHs, truck counts and car counts had significant positive correlations, with similar magnitudes for the effects of trucks and cars, despite lower truck counts. Examining all traffic variables, including traffic counts and counts divided by wind speed, the multivariate regression analysis had an adjusted coefficient of determination (R2) of 0.34 for pPAHs, with all terms significant at P < 0.002. Study staff members traversed established routes in the neighborhood while carrying instruments to record continuous UFP and pPAH values. They also carried a GPS, which was used to provide location-specific time-stamped data. Analyses using a geographic information system (GIS) demonstrated that emissions at the Peace Bridge plaza, at times, affected ambient air quality over several blocks (a few hundred meters). Under lake-wind conditions, overall spatial patterns in UFP and pPAH levels were similar for summer and winter and for morning and afternoon sampling sessions. The Buffalo Peace Bridge Study demonstrated that a concentration of motor vehicles resulted in elevated levels of mobile-source-related emissions downwind, to distances of 300 m to 600 m. The study provides a unique data set to assess interrelationships among MSATs and to ascertain the impact of heavy-duty diesel vehicles on air quality. PMID:21913504

  10. LPV H-infinity Control for the Longitudinal Dynamics of a Flexible Air-Breathing Hypersonic Vehicle

    NASA Astrophysics Data System (ADS)

    Hughes, Hunter Douglas

    This dissertation establishes the method needed to synthesize and simulate an Hinfinity Linear Parameter-Varying (LPV) controller for a flexible air-breathing hypersonic vehicle model. A study was conducted to gain the understanding of the elastic effects on the open loop system. It was determined that three modes of vibration would be suitable for the hypersonic vehicle model. It was also discovered from the open loop study that there is strong coupling in the hypersonic vehicle states, especially between the angle of attack, pitch rate, pitch attitude, and the exible modes of the vehicle. This dissertation outlines the procedure for synthesizing a full state feedback Hinfinity LPV controller for the hypersonic vehicle. The full state feedback study looked at both velocity and altitude tracking for the exible vehicle. A parametric study was conducted on each of these controllers to see the effects of changing the number of gridding points in the parameter space and changing the parameter variation rate limits in the system on the robust performance of the controller. As a result of the parametric study, a 7 x 7 grid ranging from Mach 7 to Mach 9 in velocity and from 70,000 feet to 90,000 feet in altitude, and a parameter variation rate limit of [.5 200]T was used for both the velocity tracking and altitude tracking cases. The resulting Hinfinity robust performances were gamma = 2.2224 for the velocity tracking case and = 1:7582 for the altitude tracking case. A linear analysis was then conducted on five different selected trim points from the Hinfinity LPV controller. This was conducted for the velocity tracking and altitude tracking cases. The results of linear analysis show that there is a slight difference in the response of the Hinfinity LPV controller and the fixed point H infinity controller. For the tracking task, the Hinfinity controller responds more quickly, and has a lower Hinfinity performance value. Next, the H infinity LPV controller was simulated using the nonlinear flexible hypersonic model for both the velocity tracking and altitude tracking cases. Both of these cases were subject to a ramp input and a multi-step input both with and without perturbation in the model. The results of the simulation show that the tracking state follows the command signal successfully though the perturbed system does show some higher frequency characteristics in the non-tracking states. It was discovered that there is an issue with integral windup when switching takes place in the controller, so an algorithm was implemented to reset the integration of the error on the tracking state when the switch takes place. It was also seen that there was a decline in altitude when tracking velocity, and a large change in velocity that occurred during altitude tracking. These results lead to the decision to include a unity gain regulation state on velocity for the altitude tracking and the altitude for the velocity tracking during the output feedback control synthesis. The procedure for synthesizing an output feedback H infinity LPV controller for the hypersonic vehicle is also discussed in this dissertation. The output feedback design looked at velocity tracking and altitude tracking with rigid body motion variables for both the exible and rigid body hypersonic vehicle models. As with the full state feedback controller, a parametric study was conducted on each of these controllers to determine the number of gridding points in the parameter space and the parameter variation rate limits in the system. The parametric study reveals a 7x7 grid ranging from Mach 7 to Mach 9 in velocity and from 70,000 feet to 90,000 feet in altitude, and a parameter variation rate limit of [.1 200]T is preferable for both the velocity tracking and altitude tracking cases with both the exible and rigid body assumptions. The resulting Hinfinity robust performances were gamma = 113:2146 for the exible body velocity tracking case, gamma = 83.6931 for the rigid body velocity tracking case, gamma = 107:2043 for the exible body altitude tracking case, and gamma = 97:7403 for the rigid body altitude tracking case. A linear analysis was then conducted on five different selected trim points from the Hinfinity LPV controller. The results of this analysis show that there is a larger difference in the response of the Hinfinity LPV controller and the Hinfinity controller. For the tracking task, the Hinfinity controller responds more quickly, and has a lower Hinfinity performance value. Next, the Hinfinity LPV controller was applied to the exible nonlinear plant model. The rigid body controllers were applied to the exible plant model to see if the exible nature of the vehicle could be treated as a perturbation to the system. Additionally, there were simulations run both with and without sensor noise and parametric uncertainty. The results of simulation show that the rigid body controller is able to successfully apply to the exible body model for the velocity tracking case, but is unable to stabilize the altitude tracking case. It was also seen that the system is able to track the command signal while minimizing the variations seen in the altitude for the velocity tracking case and in the velocity during the altitude tracking case. Additionally, there was no obvious effect of perturbations in the system on the tracking state or secondary regulation state. There were high frequency responses associated with the other perturbed states.

  11. Collaboration for Land, Air, Sea, and Space Vehicles: Developing the Common Ground in Vehicle Dynamics, System Identification, Control, and Handling Qualities

    NASA Astrophysics Data System (ADS)

    2002-11-01

    This technical report is the culmination of the SCI-053 Task Group - Vehicle Dynamics, System Identification, Control and Handling Qualities. It summarizes the discussions of tank, truck, aircraft, helicopter, ship, submarine and satellite experts held over a three-year period. It addresses the various technical areas identified in the name of the task group, exploring the similarities and differences between the vehicle types and identifying areas where collaboration between experts would be the most valuable. Twenty-three specific technical issues are identified as initial areas with high potential for valuable collaboration. Overall, the report provides the vehicle expert of one environment a sufficient background on the other vehicle environments, so that meaningful discussions towards these technical collaborations can be initiated.

  12. Nonlinearity, Viscosity and Air-Compressibility Effects on the Helmholtz Resonant Wave Motion Generated by an Oscillating Twin Body in a Free Surface

    NASA Astrophysics Data System (ADS)

    Ananthakrishnan, Palaniswamy

    2012-11-01

    The problem is of practical relevance in determining the motion response of multi-hull and air-cushion vehicles in high seas and in littoral waters. The linear inviscid problem without surface pressure has been well studied in the past. In the present work, the nonlinear wave-body interaction problem is solved using finite-difference methods based on boundary-fitted coordinates. The inviscid nonlinear problem is tackled using the mixed Eulerian-Lagrangian formulation and the solution of the incompressible Navier-Stokes equations governing the viscous problem using a fractional-step method. The pressure variation in the air cushion is modeled using the isentropic gas equation pVγ = Constant. Results show that viscosity and free-surface nonlinearity significantly affect the hydrodynamic force and the wave motion at the resonant Helmholtz frequency (at which the primary wave motion is the vertical oscillation of the mean surface in between the bodies). Air compressibility suppresses the Helmholtz oscillation and enhances the wave radiation. Work supported by the ONR under the grant N00014-98-1-0151.

  13. High resolution modeling of the effects of alternative fuels use on urban air quality: introduction of natural gas vehicles in Barcelona and Madrid Greater Areas (Spain).

    PubMed

    Gonalves, Mara; Jimnez-Guerrero, Pedro; Baldasano, Jos M

    2009-01-01

    The mitigation of the effects of on-road traffic emissions on urban air pollution is currently an environmental challenge. Air quality modeling has become a powerful tool to design environment-related strategies. A wide range of options is being proposed; such as the introduction of natural gas vehicles (NGV), biofuels or hydrogen vehicles. The impacts on air quality of introducing specific NGV fleets in Barcelona and Madrid (Spain) are assessed by means of the WRF-ARW/HERMES/CMAQ modeling system with high spatial-temporal resolution (1 km(2), 1 h). Seven emissions scenarios are defined taking into account the year 2004 vehicle fleet composition of the study areas and groups of vehicles susceptible of change under a realistic perspective. O(3) average concentration rises up to 1.3% in Barcelona and up to 2.5% in Madrid when introducing the emissions scenarios, due to the NO(x) reduction in VOC-controlled areas. Nevertheless, NO(2), PM10 and SO(2) average concentrations decrease, up to 6.1%, 1.5% and 6.6% in Barcelona and up to 20.6%, 8.7% and 14.9% in Madrid, respectively. Concerning SO(2) and PM10 reductions the most effective single scenario is the introduction of 50% of NGV instead of the oldest commercial vehicles; it also reduces NO(2) concentrations in Barcelona, however in Madrid lower levels are attained when substituting 10% of the private cars. This work introduces the WRF-ARW/HERMES/CMAQ modeling system as a useful management tool and proves that the air quality improvement plans must be designed considering the local characteristics. PMID:19022477

  14. Wind tunnel experiments on flow separation control of an Unmanned Air Vehicle by nanosecond discharge plasma aerodynamic actuation

    NASA Astrophysics Data System (ADS)

    Kang, Chen; Hua, Liang

    2016-02-01

    Plasma flow control (PFC) is a new kind of active flow control technology, which can improve the aerodynamic performances of aircrafts remarkably. The flow separation control of an unmanned air vehicle (UAV) by nanosecond discharge plasma aerodynamic actuation (NDPAA) is investigated experimentally in this paper. Experimental results show that the applied voltages for both the nanosecond discharge and the millisecond discharge are nearly the same, but the current for nanosecond discharge (30 A) is much bigger than that for millisecond discharge (0.1 A). The flow field induced by the NDPAA is similar to a shock wave upward, and has a maximal velocity of less than 0.5 m/s. Fast heating effect for nanosecond discharge induces shock waves in the quiescent air. The lasting time of the shock waves is about 80 μs and its spread velocity is nearly 380 m/s. By using the NDPAA, the flow separation on the suction side of the UAV can be totally suppressed and the critical stall angle of attack increases from 20° to 27° with a maximal lift coefficient increment of 11.24%. The flow separation can be suppressed when the discharge voltage is larger than the threshold value, and the optimum operation frequency for the NDPAA is the one which makes the Strouhal number equal one. The NDPAA is more effective than the millisecond discharge plasma aerodynamic actuation (MDPAA) in boundary layer flow control. The main mechanism for nanosecond discharge is shock effect. Shock effect is more effective in flow control than momentum effect in high speed flow control. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503302, 51207169, and 51276197), the China Postdoctoral Science Foundation (Grant No. 2014M562446), and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2015JM1001).

  15. Infection cushion formation by Rhizoctonia spp. on peanut and wheat root systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The formation of infection cushions by Rhizoctonia solani (isolate G-24) and R. cerealis (isolate Fellers) was examined on cellophane membranes in response to stimulation by roots of peanut (Okrun, Tamspan 90, Southwest runner and Line 209) and hard red winter wheat (Jagger, 2137, and 2174). Root s...

  16. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Building product standards and certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT...

  17. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Building product standards and certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT...

  18. New compliant strain gauges for self-sensing dynamic deformation of flapping wings on miniature air vehicles

    NASA Astrophysics Data System (ADS)

    Wissman, James; Perez-Rosado, Ariel; Edgerton, Alex; Levi, Benjamin M.; Karakas, Zeynep N.; Kujawski, Mark; Philipps, Alyssa; Papavizas, Nicholas; Fallon, Danielle; Bruck, Hugh A.; Smela, Elisabeth

    2013-08-01

    Over the past several years there has been an increasing interest in the development of miniature air vehicles (MAVs) with flapping wings. To allow these MAVs to adjust to changes in wind direction and to maximize their efficiency, it is desirable to monitor the deformation of the wing during flight. This paper presents a step in this direction, demonstrating the measurement of strain on the surface of the wing using minimally invasive compliant piezoresistive sensors. The strain gauges consisted of latex mixed with electrically conducting exfoliated graphite, and they were applied by spray coating. To calibrate the gauges, both static and dynamic testing up to 10 Hz were performed using cantilever structures. In tension the static sensitivity was a linear 0.4 ? ??-1 and the gauge factor was 28; in compression, the gauge factor was -5. Although sensitivities in tension and compression differed by a factor of almost six, this was not reflected in the dynamic data, which followed the strain reversibly with little distortion. There was no attenuation with frequency, indicating a sufficiently small time constant for this application. The gauges were thin, compliant, and light enough to measure, without interference, deformations due to shape changes of the flexible wing associated with generating lift and thrust. During flapping the resistance closely tracked the generated thrust, measured on a test stand, with both signals tracing figure-8 loops as a function of wing position throughout each cycle.

  19. Ethanol and air quality: influence of fuel ethanol content on emissions and fuel economy of flexible fuel vehicles.

    PubMed

    Hubbard, Carolyn P; Anderson, James E; Wallington, Timothy J

    2014-01-01

    Engine-out and tailpipe emissions of NOx, CO, nonmethane hydrocarbons (NMHC), nonmethane organic gases (NMOG), total hydrocarbons (THC), methane, ethene, acetaldehyde, formaldehyde, ethanol, N2O, and NH3 from a 2006 model year Mercury Grand Marquis flexible fuel vehicle (FFV) operating on E0, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer are reported. With increasing ethanol content in the fuel, the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx and NMHC decreased; while CO, ethene, and N2O emissions were not discernibly affected. NMOG and THC emissions displayed a pronounced minimum with midlevel (E20-E40) ethanol blends; 25-35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30-E40, with no further decrease seen with E55 or E80. We demonstrate that emission trends from FFVs are explained by fuel chemistry and engine calibration effects. Fuel chemistry effects are fundamental in nature; the same trend of increased ethanol, acetaldehyde, formaldehyde, and CH4 emissions and decreased NMHC and benzene emissions are expected for all FFVs. Engine calibration effects are manufacturer and model specific; emission trends for NOx, THC, and NMOG will not be the same for all FFVs. Implications for air quality are discussed. PMID:24328061

  20. Effects on Air Pollution and Regional Climate of Producing and Using Hydrogen in Fuel Cells in all U.S. OnroadVehicles

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2004-12-01

    The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3) will be available to destroy it. Results for the scenarios involving hydrogen from wind and coal gasification, and from the hybrid scenario will also be discussed, as will regional climate effects (including effects of H2O). Findings to date suggest that, even under a worst-case scenario of 10% hydrogen leakage, the conversion of the current fleet to hydrogen-fuel cell vehicles, where hydrogen is generated by steam-reforming of methane, may result in a measurable improvement in U.S. air quality.

  1. Federal certification test results for 1992 model year. Control of air pollution from new motor vehicles and new motor vehicle engines

    SciTech Connect

    Not Available

    1992-01-01

    Each manufacturer of a passenger car, (light-duty-vehicle), light-duty truck, motorcycle, heavy-duty gasoline engine, and heavy-duty diesel engine is required to demonstrate compliance with the applicable exhaust emission standard. This report contains all of the individual tests that were required by the certification-procedures found in Title 40 of the Code of Federal Regulations in Part 86. These data were submitted to the Environmental Protection Agency's Certification Division at the National Vehicle and Fuel Emissions Laboratory.

  2. Analysis of impacts on urban air quality by restricting the operation of passenger vehicles during Asian Game events in Busan, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Byeong-Kyu; Jun, Na-Young; Lee, Haengah Kim

    This study is an analysis of the impacts on urban air quality of restricting the operation of passenger vehicles during the 24th Asian Games (AG). Passenger vehicles in Busan were not allowed to operate on the alternative days during the AG period. This restricted operation of passenger vehicles was enforced to improve an urban air quality in Busan during the AG period. The average usage rate of passenger vehicles under an alternate (or restricted) operation was 95.4% and thus the average traffic flow rate (vehicle operation speed) increased approximately 28.1% as compared to normal periods. We analyzed the ambient concentrations of criteria air pollutants measured at 13 air-monitoring stations in Busan (Pusan), Korea, for the three periods of "before (13-28 September 2002)", "during (29 September-14 October 2002)" and "after (15-30 October 2002)" the AG. The 1-h, 24-h and 16-day averages or median concentrations of each classified term were compared to those of other terms. The median concentrations, based on 24-h average data of each day, of PM 10, CO, NO 2, and SO 2 in the ambient during the alternate operation period of 16 days substantially increased as compared to the terms before or after. However, the median concentration of O 3 during the AG period was slightly less than that of the term before. The ambient O 3 concentrations during daytime (12:00-19:00) under alternate operation substantially increased as compared to the terms before or after. However, the ambient O 3 concentrations during nighttime (22:00-07:00) under alternate operation decreased when compared to the terms before or after. For the alternate operation period of passenger vehicles, the average concentrations of PM 10, NO 2, SO 2, and daytime O 3 measured at the air-monitoring stations near the stadiums were much higher than those of the other areas excluding the stadium areas. However, average CO concentrations at the other areas were higher than those nearby the stadiums during the alternate operation period.

  3. Life-cycle assessment of greenhouse gas and air emissions of electric vehicles: A comparison between China and the U.S.

    NASA Astrophysics Data System (ADS)

    Huo, Hong; Cai, Hao; Zhang, Qiang; Liu, Fei; He, Kebin

    2015-05-01

    We evaluated the fuel-cycle emissions of greenhouse gases (GHGs) and air pollutants (NOx, SO2, PM10, and PM2.5) of electric vehicles (EVs) in China and the United States (U.S.), two of the largest potential markets for EVs in the world. Six of the most economically developed and populated regions in China and the U.S. were selected. The results showed that EV fuel-cycle emissions depend substantially on the carbon intensity and cleanness of the electricity mix, and vary significantly across the regions studied. In those regions with a low share of coal-based electricity (e.g., California), EVs can reduce GHG and air pollutant emissions (except for PM) significantly compared with conventional vehicles. However, in the Chinese regions and selected U.S. Midwestern states where coal dominates in the generation mix, EVs can reduce GHG emissions but increase the total and urban emissions of air pollutants. In 2025, EVs will offer greater reductions in GHG and air pollutant emissions because emissions from power plants will be better controlled; EVs in the Chinese regions examined, however, may still increase SO2 and PM emissions. Reductions of 60-85% in GHGs and air pollutants could be achieved were EVs charged with 80% renewable electricity or the electricity generated from the best available technologies of coal-fired power plants, which are futuristic power generation scenarios.

  4. Patterns of correlation between vehicle occupant seat pressure and anthropometry.

    PubMed

    Paul, Gunther; Daniell, Nathan; Fraysse, Franois

    2012-01-01

    Seat pressure is known as a major factor of seat comfort in vehicles. In passenger vehicles, there is lacking research into the seat comfort of rear seat occupants. As accurate seat pressure measurement requires significant effort, simulation of seat pressure is evolving as a preferred method. However, analytic methods are based on complex finite element modeling and therefore are time consuming and involve high investment. Based on accurate anthropometric measurements of 64 male subjects and outboard rear seat pressure measurements in three different passenger vehicles, this study investigates if a set of parameters derived from seat pressure mapping are sensitive enough to differentiate between different seats and whether they correlate with anthropometry in linear models. In addition to the pressure map analysis, H-Points were measured with a coordinate measurement system based on palpated body landmarks and the range of H-Point locations in the three seats is provided. It was found that for the cushion, cushion contact area and cushion front area/force could be modeled by subject anthropometry, while only seatback contact area could be modeled based on anthropometry for all three vehicles. Major differences were found between the vehicles for other parameters. PMID:22317045

  5. The Alpine Cushion Plant Silene acaulis as Foundation Species: A Bug’s-Eye View to Facilitation and Microclimate

    PubMed Central

    Molenda, Olivia; Reid, Anya; Lortie, Christopher J.

    2012-01-01

    Alpine ecosystems are important globally with high levels of endemic and rare species. Given that they will be highly impacted by climate change, understanding biotic factors that maintain diversity is critical. Silene acaulis is a common alpine nurse plant shown to positively influence the diversity and abundance of organisms–predominantly other plant species. The hypothesis that cushion or nurse plants in general are important to multiple trophic levels has been proposed but rarely tested. Alpine arthropod diversity is also largely understudied worldwide, and the plant-arthropod interactions reported are mostly negative, that is,. herbivory. Plant and arthropod diversity and abundance were sampled on S. acaulis and at paired adjacent microsites with other non-cushion forming vegetation present on Whistler Mountain, B.C., Canada to examine the relative trophic effects of cushion plants. Plant species richness and abundance but not Simpson’s diversity index was higher on cushion microsites relative to other vegetation. Arthropod richness, abundance, and diversity were all higher on cushion microsites relative to other vegetated sites. On a microclimatic scale, S. acaulis ameliorated stressful conditions for plants and invertebrates living inside it, but the highest levels of arthropod diversity were observed on cushions with tall plant growth. Hence, alpine cushion plants can be foundation species not only for other plant species but other trophic levels, and these impacts are expressed through both direct and indirect effects associated with altered environmental conditions and localized productivity. Whilst this case study tests a limited subset of the membership of alpine animal communities, it clearly demonstrates that cushion-forming plant species are an important consideration in understanding resilience to global changes for many organisms in addition to other plants. PMID:22655035

  6. The Bottom Line For Air Quality.

    ERIC Educational Resources Information Center

    Ellis, Tom

    2000-01-01

    Discusses how the right type of flooring can help schools reduce indoor-air-quality problems. Using vinyl composition flooring to handle moisture and reduce fungi growth is examined as are the benefits of vinyl cushion tufted textile flooring for cost effectiveness, learning environment improvement, installation, and effectiveness in emergencies.

  7. The Bottom Line For Air Quality.

    ERIC Educational Resources Information Center

    Ellis, Tom

    2000-01-01

    Discusses how the right type of flooring can help schools reduce indoor-air-quality problems. Using vinyl composition flooring to handle moisture and reduce fungi growth is examined as are the benefits of vinyl cushion tufted textile flooring for cost effectiveness, learning environment improvement, installation, and effectiveness in emergencies.…

  8. BMPER Promotes Epithelial-Mesenchymal Transition in the Developing Cardiac Cushions

    PubMed Central

    Dyer, Laura; Lockyer, Pamela; Wu, Yaxu; Saha, Arnab; Cyr, Chelsea; Moser, Martin; Pi, Xinchun; Patterson, Cam

    2015-01-01

    Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP) signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator) display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT) and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects. PMID:26418455

  9. Volatile organic chemical emissions from carpet cushions: Screening measurements. Final report

    SciTech Connect

    Hodgson, A.T.; Phan, T.A.

    1994-05-01

    The US Consumer Product Safety Commission (CPSC) has received complaints from consumers regarding the occurrence of adverse health effects following the installation of new carpeting (Schachter, 1990). Carpet systems are suspected of emitting chemicals which may be the cause of these complaints, as well as objectionable odors. Carpets themselves have been shown to emit a variety of volatile organic compounds (VOCs). The objective of this study was to screen the representative samples of carpet cushions for emissions of individual VOCS, total VOCs (TVOC), formaldehyde, and, for the two types of polyurethane cushions, isomers of toluene diisocyanate (TDI). The measurements of VOCS, TVOC and formaldehyde were made over six-hour periods using small-volume (4-L) dynamic chambers. Sensitive gas chromatography-mass spectrometry (GC-MS) techniques were used to identify many of the VOCs emitted by the cushion samples and to obtain quantitative estimates of the emission rates of selected compounds. Separate screening measurements were conducted for TDI. The data from the screening measurements were used by the CPSC`s Health Sciences Laboratory to help design and conduct week-long measurements of emission rates of selected compounds.

  10. Behaviour of Load-Bearing Components of a Cushioned Composite Piled Raft Foundation Under Axial Loading

    NASA Astrophysics Data System (ADS)

    Sharma, V. J.; Vasanvala, S. A.; Solanki, C. H.

    2014-12-01

    In the last decade piled raft foundations have been widely used around the world as intermediate foundation systems between piles and rafts to control the settlement of foundations. However, when those piles are structurally connected to rafts, relatively high axial stresses develop in relatively small numbers of piles, which are often designed to fully mobilize their geotechnical capacities. To avoid a concentration of stress at the head of piles in a traditional piled raft foundation, the raft is disconnected from the piles, and a cushion is introduced between them. Also, to tackle an unfavourable soil profile for a piled raft foundation, the conventional piled raft has been modified into a cushioned composite piled raft foundation, where piles of different materials are used. In the current study the behavior of cushioned foundation components, which transfer the load from the structure to the subsoil, are analyzed in detail, i.e., the thickness of the raft, the length of a long pile and the modulus of a flexible pile.

  11. Clean Cities ozone air quality attainment and maintenance strategies that employ alternative fuel vehicles, with special emphasis on natural gas and propane

    SciTech Connect

    Santini, D.J.; Saricks, C.L.

    1998-08-04

    Air quality administrators across the nation are coming under greater pressure to find new strategies for further reducing automotive generated non-methane hydrocarbon (NMHC) and nitrogen oxide (NOx) emissions. The US Environmental Protection Agency (EPA) has established stringent emission reduction requirements for ozone non-attainment areas that have driven the vehicle industry to engineer vehicles meeting dramatically tightened standards. This paper describes an interim method for including alternative-fueled vehicles (AFVs) in the mix of strategies to achieve local and regional improvements in ozone air quality. This method could be used until EPA can develop the Mobile series of emissions estimation models to include AFVs and until such time that detailed work on AFV emissions totals by air quality planners and emissions inventory builders is warranted. The paper first describes the challenges confronting almost every effort to include AFVs in targeted emissions reduction programs, but points out that within these challenges resides an opportunity. Next, it discusses some basic relationships in the formation of ambient ozone from precursor emissions. It then describes several of the salient provisions of EPA`s new voluntary emissions initiative, which is called the Voluntary Mobile Source Emissions Reduction Program (VMEP). Recent emissions test data comparing gaseous-fuel light-duty AFVs with their gasoline-fueled counterparts is examined to estimate percent emissions reductions achievable with CNG and LPG vehicles. Examples of calculated MOBILE5b emission rates that would be used for summer ozone season planning purposes by an individual Air Quality Control Region (AQCR) are provided. A method is suggested for employing these data to compute appropriate voluntary emission reduction credits where such (lighter) AFVs would be acquired. It also points out, but does not quantify, the substantial reduction credits potentially achievable by substituting gaseous-fueled for gasoline-fueled heavy-duty vehicles. Finally, it raises and expands on the relevance of AFVs and their deployment to some other provisions embedded in EPA`s current guidance for implementing 1-hour NAAQS--standards which currently remain in effect--as tools to provide immediate reductions in ozone, without waiting for promised future clean technologies.

  12. Ethical and economic issues in the use of zero-emission vehicles as a component of an air-pollution mitigation strategy.

    PubMed

    Duvall, Tim; Englander, Fred; Englander, Valerie; Hodson, Thomas J; Marpet, Mark

    2002-10-01

    The air pollution generated by motor vehicles and by static sources is, in certain geographic areas, a very serious problem, a problem that exists because of a failure of the marketplace. To address this marketplace failure, the State of California has mandated that by 2003, 10% of the Light-Duty Vehicle Fleet (LDV) be composed of Zero-Emission Vehicles (ZEVs). However, the policy-making process that was utilized to generate the ZEV mandate was problematic and the resulting ZEV mandate is economically unsound. Moreover, an ethical analysis, based primarily upon the work of John Rawls, suggests that implementation of the California ZEV mandate is--in spite of the wide latitude that ought to be given to policy decision makers--unethical. A more ethical and economically efficient approach to the pollution caused by marketplace failure is one that relies on market incentives and thereby achieves the desired improvement in air quality by appealing both to the self-interest of motorists and to those businesses that are directly or indirectly involved with the automobile industry. Such an approach would take better advantage of the creative forces of the market and improvements in technology over time and avoid the infringements on individual liberty and fairness embodied in the ZEV mandate. PMID:12501725

  13. Energy absorption capability of foam-based composite materials and their applications as seat cushions in aircraft crashworthiness

    NASA Astrophysics Data System (ADS)

    Kh. Beheshti, Hamid

    This study is focusing on the application of foam materials in aviation. These materials are being used for acoustic purposes, as padding in the finished interior panels of the aircraft, and as seat cushions. Foams are mostly used in seating applications. Since seat cushion is directly interacting with the body of occupant, it has to be ergonomically comfortable beside of absorbing the energy during the impact. All the seats and seat cushions have to pass regulations defined by Federal Aviation Administration (FAA). In fact, all airplane companies are required to certify the subcomponents of aircrafts before installing them on the main structure, fuselage. Current Federal Aviation Administration Regulations require a dynamic sled test of the entire seat system for certifying the seat cushions. This dynamic testing is required also for replacing the deteriorated cushions with new cushions. This involves a costly and time-consuming certification process. AGATE group has suggested a procedure based on quasi-static testing in order to certify new seat cushions without conducting full-scale dynamic sled testing. AGATE subcomponent methodology involves static tests of the energy-absorbing foam cushions and design validation by conducting a full-scale dynamic seat test. Microscopic and macroscopic studies are necessary to provide a complete understanding about performance of foams during the crash. Much investigation has been done by different sources to obtain the reliable modeling in terms of demonstration of mechanical behavior of foams. However, rate sensitivity of foams needs more attention. A mathematical hybrid dynamic model for the cushion underneath of the human body will be taken into consideration in this research. Analytical and finite element codes such as MADYMO and LS-DYNA codes have the potential to greatly speed up the crashworthy design process, to help certify seats and aircraft to dynamic crash loads, to predict seat and occupant response to impact with the probability of injury, and to evaluate numerous crash scenarios not economically feasible with full-scale crash testing. Therefore, these codes are being used to find the accurate response of spinal load during the impact of model including human body, seat cushion and seat under different acceleration pulses. (Abstract shortened by UMI.)

  14. Static-electric field induction by a silicone cushion for the treatment of hypertrophic and keloid scars.

    PubMed

    Hirshowitz, B; Lindenbaum, E; Har-Shai, Y; Feitelberg, L; Tendler, M; Katz, D

    1998-04-01

    Silicone gel and silicone occlusive sheeting are widely used at present for the treatment of hypertrophic and keloid scars, without any scientific explanation as to their mode of action. In a recent paper the possibility was raised that static electricity generated by friction-activated silicone sheeting could be the reason for this effect, and that it can, with time, cause involution of hypertrophic and keloid scars. The objective of this study was to test this hypothesis and to observe whether a continuous and also an increased negatively charged static-electric field will shorten the treatment period. A device to implement these requirements gradually evolved over a 5-year period. A number of prototypes were tested until the final product was attained. Some of the patients in this study were treated initially with a silicone sponge inserted in the cushion. Later this version was changed to the final design described herein. A silicone cushion was developed with the purpose of increasing a negative static-electric charge to accelerate the regression process. The cushion is custom-made using a silicone occlusive sheeting envelope of 0.75-mm thickness, which does not deteriorate with use, and is partially filled with high viscosity silicone oil. Its edges are sealed, and its size is designed to extend a little beyond the scarred area. Static electricity readings, generated by activating the cushion by pumping action with the fingers, stretching or deforming the cushion, are invariably much higher when compared with those obtained with silicone occlusive sheeting and silicone gel sheeting. The interaction between the negatively charged ions of the cushion and the ionic charges of the tissue fluids may be the critical factor in achieving hypertrophic and keloid scars involution. Of the 30 patients enrolled in the study, 3 patients dropped out. Treatment with the silicone cushions yielded 63.3 percent cessation of itching and burning followed by pallor and flattening of the scar, some markedly so, over a few weeks to 6-month period. An additional 26.6 percent had their scars resolved in up to 12 months of treatment. Good contact of the cushion over the scar has been shown to be important in this clinical trial, and much creativity is needed for making elastic strap bindings that ensure this contact. The clinical trials extended over a 12-month period. Ten patients (33.3 percent) who had recalcitrant scars with little response to the use of the silicone cushion were given intralesional corticosteroid injections, in addition to the continued use of the cushion, resulting in a fairly rapid resolution of these scars over a period of months to a year. PMID:9529199

  15. Crystallization Behavior of M97 Series Silicone Cushions

    SciTech Connect

    Chien, A.; DeTeresa, S.; Cohenour, R.; Schnieder, J.; LeMay, J.; Balazs, B.

    2000-09-07

    M97 series siloxanes are poly(dimethyl-diphenyl) siloxanes that are reinforced through a mixture of precipitated and fumed silica fillers which are blended in through the addition of a short chain polydimethylsiloxane processing aid. M97 silicones exhibit crystallization at -80.25 C by thermal (modulated differential scanning calorimetry) and mechanical (dynamic mechanical analysis) techniques. Isothermal dynamic mechanical analysis experiments illustrated that crystallization occurred over a 1.8 hour period in silica-filled systems and 2.8 hours in unfilled systems. The onset of crystallization typically occurred after a 30 minute incubation/nucleation period. {gamma}-radiation caused the crystallization rate to decrease proportionally with dosage, but did not decrease the amount of crystallization that ultimately occurred. Irradiation in vacuum resulted in slower overall crystallization rates compared to air irradiation due to increased crosslinking of the polymer matrix under vacuum. Modulated differential scanning calorimetry contrasted the crystallization and melting behavior of pure PDMS versus the M97 base polymer and helped determine which component of the composite was the origin of the crystallization phenomena.

  16. Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

    SciTech Connect

    Cooper, J.F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K.; Koopman, R.

    1994-08-08

    We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

  17. Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module

    NASA Astrophysics Data System (ADS)

    Cooper, J. F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K.; Koopman, R.

    1994-08-01

    We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute, indicating a refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

  18. Membrane-Based Air Composition Control for Light-Duty Diesel Vehicles: A Benefit and Cost Assessment

    SciTech Connect

    K. Stork; R. Poola

    1998-10-01

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM{sub 2.5}). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles.

  19. Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications

    NASA Astrophysics Data System (ADS)

    Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Lffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

    2014-05-01

    In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1C and 0.8C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different radiation protection. Duration of each measurement tour lasted approximately 2 hours covering the distances in radius of about 10-30 km, logging the air temperature and geographical positioning in intervals of 1-5 seconds. The collected data were aggregated on a 100 m horizontal resolution grid and compared with the local-scale climate modelling simulations with the urban climate model MUKLIMO3 initialized with the atmospheric conditions for a given day. Both measurement and modelling results show similar features for distinct local climate zones (built-up area, near water environment, forest, parks, agricultural area, etc). The spatial gradients in temperature can be assigned to different orographical and land use characteristics. Even if many ambiguities remain in both modelling and the measurement approach, the collected data provide useful information for local-scale heat assessment and can serve as a base to increase the model reliability, especially in areas with low data coverage.

  20. Metal-Air Electric Vehicle Battery: Sustainable, High-Energy Density, Low-Cost Electrochemical Energy Storage Metal-Air Ionic Liquid (MAIL) Batteries

    SciTech Connect

    2009-12-21

    Broad Funding Opportunity Announcement Project: ASU is developing a new class of metal-air batteries. Metal-air batteries are promising for future generations of EVs because they use oxygen from the air as one of the batterys main reactants, reducing the weight of the battery and freeing up more space to devote to energy storage than Li-Ion batteries. ASU technology uses Zinc as the active metal in the battery because it is more abundant and affordable than imported lithium. Metal-air batteries have long been considered impractical for EV applications because the water-based electrolytes inside would decompose the battery interior after just a few uses. Overcoming this traditional limitation, ASUs new battery system could be both cheaper and safer than todays Li-Ion batteries, store from 4-5 times more energy, and be recharged over 2,500 times.

  1. Can static interface pressure mapping be used to rank pressure-redistributing cushions for active wheelchair users?

    PubMed

    Hollington, James; Hillman, Susan J

    2013-01-01

    Interface pressure mapping (IPM) is a clinical tool that assists the selection of seat cushions for pressure management for wheelchair users. Clinical pressure measurements are almost always made under static sitting conditions, although this does not consider the time-dependent properties of some cushion materials that may behave differently under the dynamic conditions of self-propulsion. This study investigated the potential for such differences by collecting seat IPM measurements from eight wheelchair users using four different seat cushion designs during static sitting and self-propulsion. Mean pressure corresponding to the approximate anatomical location of the ischial tuberosities was used to rank the four cushions under the two conditions. The two sets of rankings for each participant were then compared using correlation. Dynamic data from four participants was judged too inconsistent to be interpreted reliably and demonstrates the practical difficulties associated with dynamic IPM measurement when variations in individual propulsion technique cannot be controlled. Strong correlations were observed between rank orders for the remaining four participants and suggest that the statically derived pressure measures can be used for clinical decision making when selecting cushions for self-propelling wheelchair users. PMID:23516083

  2. Bacterial community of cushion plant Thylacospermum ceaspitosum on elevational gradient in the Himalayan cold desert.

    PubMed

    ?ehkov, Klra; Chro?kov, Alica; Krit?fek, Vclav; Kuchtov, Barbora; ?apkov, Kate?ina; Scharfen, Josef; ?apek, Petr; Doleal, Ji?

    2015-01-01

    Although bacterial assemblages are important components of soils in arid ecosystems, the knowledge about composition, life-strategies, and environmental drivers is still fragmentary, especially in remote high-elevation mountains. We compared the quality and quantity of heterotrophic bacterial assemblages between the rhizosphere of the dominant cushion-forming plant Thylacospermum ceaspitosum and its surrounding bulk soil in two mountain ranges (East Karakoram: 4850-5250 m and Little Tibet: 5350-5850 m), in communities from cold steppes to the subnival zone in Ladakh, arid Trans-Himalaya, northwest India. Bacterial communities were characterized by molecular fingerprinting in combination with culture-dependent methods. The effects of environmental factors (elevation, mountain range, and soil physico-chemical parameters) on the bacterial community composition and structure were tested by multivariate redundancy analysis and conditional inference trees. Actinobacteria dominate the cultivable part of community and represent a major bacterial lineage of cold desert soils. The most abundant genera were Streptomyces, Arthrobacter, and Paenibacillus, representing both r- and K-strategists. The soil texture is the most important factor for the community structure and the total bacteria counts. Less abundant and diverse assemblages are found in East Karakoram with coarser soils derived from leucogranite bedrock, while more diverse assemblages in Little Tibet are associated with finer soils derived from easily weathering gneisses. Cushion rhizosphere is in general less diverse than bulk soil, and contains more r-strategists. K-strategists are more associated with the extremes of the gradient, with drought at lowest elevations (4850-5000 m) and frost at the highest elevations (5750-5850 m). The present study illuminates the composition of soil bacterial assemblages in relation to the cushion plant T. ceaspitosum in a xeric environment and brings important information about heterotrophic bacteria in Himalayan soil. PMID:25932023

  3. Bacterial community of cushion plant Thylacospermum ceaspitosum on elevational gradient in the Himalayan cold desert

    PubMed Central

    Řeháková, Klára; Chroňáková, Alica; Krištůfek, Václav; Kuchtová, Barbora; Čapková, Kateřina; Scharfen, Josef; Čapek, Petr; Doležal, Jiří

    2015-01-01

    Although bacterial assemblages are important components of soils in arid ecosystems, the knowledge about composition, life-strategies, and environmental drivers is still fragmentary, especially in remote high-elevation mountains. We compared the quality and quantity of heterotrophic bacterial assemblages between the rhizosphere of the dominant cushion-forming plant Thylacospermum ceaspitosum and its surrounding bulk soil in two mountain ranges (East Karakoram: 4850–5250 m and Little Tibet: 5350–5850 m), in communities from cold steppes to the subnival zone in Ladakh, arid Trans-Himalaya, northwest India. Bacterial communities were characterized by molecular fingerprinting in combination with culture-dependent methods. The effects of environmental factors (elevation, mountain range, and soil physico-chemical parameters) on the bacterial community composition and structure were tested by multivariate redundancy analysis and conditional inference trees. Actinobacteria dominate the cultivable part of community and represent a major bacterial lineage of cold desert soils. The most abundant genera were Streptomyces, Arthrobacter, and Paenibacillus, representing both r- and K-strategists. The soil texture is the most important factor for the community structure and the total bacteria counts. Less abundant and diverse assemblages are found in East Karakoram with coarser soils derived from leucogranite bedrock, while more diverse assemblages in Little Tibet are associated with finer soils derived from easily weathering gneisses. Cushion rhizosphere is in general less diverse than bulk soil, and contains more r-strategists. K-strategists are more associated with the extremes of the gradient, with drought at lowest elevations (4850–5000 m) and frost at the highest elevations (5750–5850 m). The present study illuminates the composition of soil bacterial assemblages in relation to the cushion plant T. ceaspitosum in a xeric environment and brings important information about heterotrophic bacteria in Himalayan soil. PMID:25932023

  4. 77 FR 73459 - California State Motor Vehicle Pollution Control Standards; Notice of Waiver of Clean Air Act...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ...\\ See, e.g., 71 FR 44027 at 44028 (August 3, 2006)(``EPA believed it possible that CARB's amendments do... Resources Board (CARB) its request to confirm that its amendments to California's heavy-duty vehicle and... upon in making this decision, including those submitted to ] EPA by CARB, are contained in the...

  5. UPDATED PHOTOCHEMICAL MODELING FOR CALIFORNIA'S SOUTH COAST AIR BASIN: COMPARISON OF CHEMICAL MECHANISMS AND MOTOR VEHICLE EMISSION INVENTORIES. (R824792)

    EPA Science Inventory

    Large uncertainties remain in photochemical models used
    to relate emissions of VOC and NOx to ambient
    O3
    concentrations. Bias in motor vehicle emission
    estimates
    for VOC has been a long-standing concern. An improved
    Eul...

  6. Variations in speciated emissions from spark-ignition and compression-ignition motor vehicles in California's south coast air basin.

    PubMed

    Fujita, Eric M; Zielinska, Barbara; Campbell, David E; Arnott, W Patrick; Sagebiel, John C; Mazzoleni, Lynn; Chow, Judith C; Gabele, Peter A; Crews, William; Snow, Richard; Clark, Nigel N; Wayne, W Scott; Lawson, Douglas R

    2007-06-01

    The U.S. Department of Energy Gasoline/Diesel PM Split Study examined the sources of uncertainties in using an organic compound-based chemical mass balance receptor model to quantify the contributions of spark-ignition (SI) and compression-ignition (CI) engine exhaust to ambient fine particulate matter (PM2.5). This paper presents the chemical composition profiles of SI and CI engine exhaust from the vehicle-testing portion of the study. Chemical analysis of source samples consisted of gravimetric mass, elements, ions, organic carbon (OC), and elemental carbon (EC) by the Interagency Monitoring of Protected Visual Environments (IMPROVE) and Speciation Trends Network (STN) thermal/optical methods, polycyclic aromatic hydrocarbons (PAHs), hopanes, steranes, alkanes, and polar organic compounds. More than half of the mass of carbonaceous particles emitted by heavy-duty diesel trucks was EC (IMPROVE) and emissions from SI vehicles contained predominantly OC. Although total carbon (TC) by the IMPROVE and STN protocols agreed well for all of the samples, the STN/IMPROVE ratios for EC from SI exhaust decreased with decreasing sample loading. SI vehicles, whether low or high emitters, emitted greater amounts of high-molecular-weight particulate PAHs (benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and coronene) than did CI vehicles. Diesel emissions contained higher abundances of two- to four-ring semivolatile PAHs. Diacids were emitted by CI vehicles but are also prevalent in secondary organic aerosols, so they cannot be considered unique tracers. Hopanes and steranes were present in lubricating oil with similar composition for both gasoline and diesel vehicles and were negligible in gasoline or diesel fuels. CI vehicles emitted greater total amounts of hopanes and steranes on a mass per mile basis, but abundances were comparable to SI exhaust normalized to TC emissions within measurement uncertainty. The combustion-produced high-molecular-weight PAHs were found in used gasoline motor oil but not in fresh oil and are negligible in used diesel engine oil. The contributions of lubrication oils to abundances of these PAHs in the exhaust were large in some cases and were variable with the age and consumption rate of the oil. These factors contributed to the observed variations in their abundances to total carbon or PM2.5 among the SI composition profiles. PMID:17608006

  7. Relationship-Based Care for Newborns With Down Syndrome and Endocardial Cushion Defect.

    PubMed

    Phillips, Cathi; Boyd, Margaret

    2015-01-01

    Down syndrome with endocardial cushion defect is a challenging diagnosis for parents as well as members of the health care team. Utilizing a framework of relationship-based care, nurses are in a position to positively affect parents' experience by providing education, advocacy, and support from initial diagnosis through discharge. The plan of care is multidisciplinary and focuses on critical developmental needs, such as bonding and feeding. Because Down syndrome is associated with multiple anomalies, anticipatory guidance is needed to assist parents with establishing a health maintenance plan for their child after discharge. PMID:26460913

  8. Estimation of exhaust and non-exhaust gaseous, particulate matter and air toxics emissions from on-road vehicles in Delhi

    NASA Astrophysics Data System (ADS)

    Nagpure, Ajay Singh; Gurjar, B. R.; Kumar, Vivek; Kumar, Prashant

    2016-02-01

    Analysis of emissions from on-road vehicles in an Indian megacity, Delhi, have been performed by comparing exhaust emissions of gaseous, particulate matter and mobile source air toxics (MSATs), together with volatile organic compound (VOCs) and PM10 (particulate matter ≤10 μm) from non-exhaust vehicular sources, during the past (1991-2011) and future (2011-2020) scenarios. Results indicate that emissions of most of the pollutants from private vehicles (two wheelers and cars) have increased by 2- to 18-times in 2020 over the 1991 levels. Two wheelers found to be dominating the emissions of carbon monoxide (CO, 29-51%), hydrocarbons (HC, 45-73%), acetaldehyde (46-51%) and total poly aromatic hydrocarbons (PAHs, 37-42%). Conversely, private cars were found to be responsible for the majority of the carbon dioxide (CO2, 24-42%), 1,3-butadiene (72-89%), benzene (60-82%), formaldehyde (23-44%) and total aldehyde (27-52%) between 1991 and 2011. The heavy-duty commercial vehicles (HCVs) shows their accountability for most of the nitrogen oxide (NOx, 18-41%) and PM10 (33-43%) emissions during the years 1991-2011. In terms of PM10 emissions, vehicular exhaust contributed by 21-55%, followed by road dust (42-73%) and brake wear (3-5%) between 1991 and 2011. After 2002, non-exhaust emissions (e.g. road dust, brake wear and tyre wear) together indicate higher accountability (66-86%) for PM10 emission than the exhaust emissions (14-34%). The temporal trend of emissions of NOx and CO show reasonable agreement with available ambient air concentrations that were monitored at locations, significantly influenced by vehicular activity. Encouraging results were emerged, showing a good correlation coefficient for CO (0.94) and NOx (0.68).

  9. Transportation by Air-On the Ground

    NASA Technical Reports Server (NTRS)

    1985-01-01

    A Rolair air flotation system is a spinoff of NASA/General Motors technology developed for the Apollo Program. It allows heavy loads to be moved easily by separating the load from the ground by a thin air cushion, virtually eliminating surface friction. Rolair Systems, Inc. was formed by former General Motors engineers and has successfully employed the system for both aerospace and nonaerospace industries.

  10. N-Acetyl-S-(n-Propyl)-L-Cysteine in Urine from Workers Exposed to 1-Bromopropane in Foam Cushion Spray Adhesives

    PubMed Central

    Hanley, Kevin W.; Petersen, Martin R.; Cheever, Kenneth L.; Luo, Lian

    2009-01-01

    1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br(?)] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br(?) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers. PMID:19706636

  11. Autonomous vehicles

    SciTech Connect

    Meyrowitz, A.L.; Blidberg, D.R.; Michelson, R.C.

    1996-08-01

    There are various kinds of autonomous vehicles (AV`s) which can operate with varying levels of autonomy. This paper is concerned with underwater, ground, and aerial vehicles operating in a fully autonomous (nonteleoperated) mode. Further, this paper deals with AV`s as a special kind of device, rather than full-scale manned vehicles operating unmanned. The distinction is one in which the AV is likely to be designed for autonomous operation rather than being adapted for it as would be the case for manned vehicles. The authors provide a survey of the technological progress that has been made in AV`s, the current research issues and approaches that are continuing that progress, and the applications which motivate this work. It should be noted that issues of control are pervasive regardless of the kind of AV being considered, but that there are special considerations in the design and operation of AV`s depending on whether the focus is on vehicles underwater, on the ground, or in the air. The authors have separated the discussion into sections treating each of these categories.

  12. The effect of cushioning insoles on back and lower extremity pain in an industrial setting.

    PubMed

    Jefferson, John R

    2013-10-01

    The purpose of this study was to examine the relationship between low back pain and lower extremity pain in a group of factory workers and determine the effect of cushioning insoles on low back pain and lower extremity pain. Data were gathered via questionnaire from 306 employees of an aircraft engine assembly factory. A subset of 40 workers who had reported significant levels of back or lower extremity pain were sampled for four consecutive 12-hour shifts wearing their normal footwear and then a week later for four consecutive shifts wearing cushioning insoles. High levels of low back pain and lower extremity pain were reported by workers on the plant floor, but low back pain was poorly correlated to lower extremity pain (r = 0.371). The effect of insoles on the subset of 40 workers was to lower low back pain by 38%, foot pain by 37%, and knee pain by 38% (p < .001). The reduction in low back pain, however, was not correlated to the reduction in lower extremity pain; workers reporting a decrease in low back pain differed from those reporting less lower extremity pain. PMID:24053218

  13. [Grading of the functional sport shoe parameter "cushioning" and "forefoot flexibility" on running shoes].

    PubMed

    Kleindienst, F I; Krabbe, B; Walther, M; Brggemann, G-P

    2006-03-01

    On nearly every running event a heterogeneous structure of participants regarding body height and body weight can be observed. This study should figure out whether the running shoe manufacturers will consider this anthropometric variability. Moreover it should be investigated the runners needs based on different anthropometrics regarding preferred cushioning and forefoot flexibility properties. In order to check whether the running shoe manufacturers will apply a grading pattern, a dynamic material study with conventional running shoes in different sizes was conducted. In a second step a field study in Middle Europe and North America with 244 female and 227 male runners was organized. Every subject had to run and evaluate 7 different shoe modifications. Based on the material study it is to state, that the running shoe manufacturers currently do not consider a systematic grading of cushioning and forefoot flexibility properties. In contrast to this, the field study reveals the necessity to grade these properties. A shoe size dependent and a geographic grading concept are suggested. It is supposed, that the application of these grading concepts do not only provide a comfort improvement, but they also contribute to a reduction of joint loads of the lower extremities and consequently to a prevention of overuse injuries. PMID:16544212

  14. Exposure to acid anhydrides in three resin and one cushioned flooring manufacturing plants.

    PubMed

    van Tongeren, M J; Barker, R D; Gardiner, K; Harris, J M; Venables, K M; Taylor, A J; Harrington, J M

    1995-10-01

    Acid anhydrides are reactive organic chemicals of low molecular weight which cause occupational asthma. No previous research on the relationship between exposure to these chemicals and respiratory sensitization and development of occupational asthma has been reported. A retrospective cohort study was carried out in four factories (three alkyd resin factories and one cushioned flooring factory) to investigate the nature of exposure-response relationships for sensitization to phthalic anhydride (PA), trimellitic anhydride (TMA) and maleic anhydride (MA). This paper describes the results of full-shift and task-specific exposure measurements. Exposure to PA was low in relation to the Occupational Exposure Standard (OES). The highest full-shift PA exposures occurred among resin operators in the resin factory that used solid PA as compared to other resin factories where liquid PA was used. Arithmetic mean exposure levels to TMA and MA in the resin factories were well below their respective OESs. Short-term high exposures occurred during loading of acid anhydrides into the reactors and sampling and testing of the resin. Relatively high full-shift exposure to TMA occurred in the cushioned flooring factory, although no high peak exposures were detected. PMID:8526391

  15. Influence of mobile air-conditioning on vehicle emissions and fuel consumption: a model approach for modern gasoline cars used in Europe.

    PubMed

    Weilenmann, Martin F; Vasic, Ana-Marija; Stettler, Peter; Novak, Philippe

    2005-12-15

    The influence of air-conditioning activity on the emissions and fuel consumption of passenger cars is an important issue, since fleet penetration and use of these systems have reached a high level. Apart from the MOBILE6 study in the United States, little data is available on the impact of air-conditioning devices (A/Cs). Since weather conditions and A/C technologies both differ from those in the U. S., a test series was designed for the European setting. A fleet of six modern gasoline passenger cars was tested in different weather conditions. Separate test series were carried out for the initial cooldown and for the stationary situation of keeping the interior of the vehicle cool. As assumed, CO2 emissions and fuel consumption rise with the thermal load. This also causes a notable rise in CO and hydrocarbons (HCs). Moreover, A/Cs do not stop automatically at low ambient temperatures; if necessary, they produce dry air to demist the windscreen. A model is proposed that shows a constant load for lower temperatures and a linear trend for higher temperatures. The initial cooldown tests highlight significant differences among cars but show that A/C operation for the initial cooling of an overheated passenger compartment does not result in any extra emissions for the fleet as a whole. PMID:16475341

  16. Flapping Wing Micro Air Vehicles: An Analysis of the Importance of the Mass of the Wings to Flight Dynamics, Stability, and Control

    NASA Astrophysics Data System (ADS)

    Orlowski, Christopher T.

    The flight dynamics, stability, and control of a model flapping wing micro air vehicle are analyzed with a focus on the inertial and mass effects of the wings on the position and Orientation of the body. A multi-body, flight dynamics model is derived from first principles. The multi-body model predicts significant differences in the position and orientation of the flapping wing micro air vehicle, when compared to a flight dynamics model based on the standard aircraft, or six degree of freedom, equations of motion. The strongly coupled, multi-body equations of motion are transformed into first order form using an approximate inverse and appropriate assumptions. Local (naive) averaging of the first order system does not produce an accurate result and a new approximation technique named 'quarter-cycle' averaging is proposed. The technique is effective in reducing the error by at least an order of magnitude for three reference flight conditions. A stability analysis of the local averaged equations of motions, in the vicinity of a hover condition, produces a modal structure consist with the most common vertical takeoff or landing structure and independent stability analyses of the linearized flight dynamics of insect models. The inclusion of the wing effects produces a non-negligible change in the linear stability of a hawkmoth-sized model. The hovering solution is shown, under proper control, to produce a limit cycle. The control input to achieve a limit cycle is different if the flight dynamics model includes the wing effects or does not include the wing effects. Improper control input application will not produce the desired limit cycle effects. A scaling analysis is used to analyze the relative importance of the mass of the wings, based on the quarter-cycle approximation. The conclusion of the scaling analysis is that the linear momentum effects of the wings are always important in terms of the inertial position of the flapping wing micro air vehicle. Above a flapping frequency of approximately 30-40 Hz, the mass and inertial effects of the wings on the orientation of the body can be neglected.

  17. Cushions of Thylacospermum caespitosum (Caryophyllaceae) do not facilitate other plants under extreme altitude and dry conditions in the north-west Himalayas

    PubMed Central

    de Bello, Francesco; Doleal, Ji?; Dvorsk, Miroslav; Chlumsk, Zuzana; ?ehkov, Klra; Klimeov, Jitka; Klime, Leo

    2011-01-01

    Background Cushion plants are commonly considered as keystone nurse species that ameliorate the harsh conditions they inhabit in alpine ecosystems, thus facilitating other species and increasing alpine plant biodiversity. A literature search resulted in 25 key studies showing overwhelming facilitative effects of different cushion plants and hypothesizing greater facilitation with increased environmental severity (i.e. higher altitude and/or lower rainfall). At the same time, emerging ecological theory alongside the cushion-specific literature suggests that facilitation might not always occur under extreme environmental conditions, and especially under high altitude and dryness. Methods To assess these hypotheses, possible nursing effects of Thylacospermum caespitosum (Caryophyllaceae) were examined at extremely high altitude (5900 m a.s.l.) and in dry conditions (precipitation <100 mm year?1) in Eastern Ladakh, Trans-Himalaya. This is, by far, the highest site, and the second driest, at which the effects of cushions have been studied so far. Key Results In accordance with the theoretical predictions, no nursing effects of T. caespitosum on other alpine plants were detected. The number and abundance of species were greater outside cushions than within and on the edge of cushions. None of the 13 species detected was positively associated with cushions, while nine of them were negatively associated. Plant diversity increased with the size of the area sampled outside cushions, but no speciesarea relationship was found within cushions. Conclusions The results support the emerging theoretical prediction of restricted facilitative effects under extreme combinations of cold and dryness, integrating these ideas in the context of the ecology of cushion plants. This evidence suggests that cases of missing strong facilitation are likely to be found in other extreme alpine conditions. PMID:21813564

  18. Aerothermodynamic measurements on a proposed assured crew return vehicle (ACRV) lifting-body configuration at Mach 6 and 10 in air

    NASA Technical Reports Server (NTRS)

    Horvath, Thomas J.; Rhode, Matthew N.; Buck, Gregory M.

    1990-01-01

    A 0.02-scale model of a lifting-body concept for possible application to the Assured Crew Return Vehicle from Space Station Freedom was tested at Mach 6 and 10 in air. Thermal mappings and surface streamline patterns were obtained at angles of attack ranging from 0 to 30 deg and unit Reynolds numbers Re from 2 to 8 x 10 to the 6th/ft. Areas that experienced the highest heating were near the model nose and tip-fin leading edges. The effect of Re on windward centerline heating coefficients was negligible, whereas increases in angles of attack produced increases in heating. At Mach 6 and the highest unit Re, turbulent heat at the windward centerline was three to four times the laminar level. Leeward crossflow separation and vortex reattachment along the centerline are evident across the Re and angle-of-attack ranges tested, indicative of a complex flowfield.

  19. A synergistic glance at the prospects of distributed propulsion technology and the electric aircraft concept for future unmanned air vehicles and commercial/military aviation

    NASA Astrophysics Data System (ADS)

    Gohardani, Amir S.

    2013-02-01

    Distributed propulsion is one of the revolutionary candidates for future aircraft propulsion. In this journal article, the potential role of distributed propulsion technology in future aviation is investigated. Following a historical journey that revisits distributed propulsion technology in unmanned air vehicles and military aircraft, features of this specific technology are highlighted in synergy with an electric aircraft concept and a first-of-a-kind comparison to commercial aircraft employing distributed propulsion arrangements. In light of propulsion-airframe integration and complementary technologies such as boundary layer ingestion, thrust vectoring and circulation control, transpired opportunities and challenges are addressed in addition to a number of identified research directions proposed for future aircraft. The motivation behind enhanced means of communication between engineers, researchers and scientists has stimulated a novel proposed definition for the distributed propulsion technology in aviation and is presented herein.

  20. Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel

    NASA Technical Reports Server (NTRS)

    Liechty, Derek S.

    2008-01-01

    An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

  1. Breaking the Fall: Cushioning the Impact of Rural Declining Enrollment. Rural Trust Policy Brief Series on Rural Education

    ERIC Educational Resources Information Center

    Jimerson, Lorna

    2006-01-01

    For those rural schools and communities across the country facing declining student enrollment, there are no easy answers. But there are steps policymakers and communities can take to help cushion the negative impact of declining enrollment on schools to ensure that "no child left behind" also means "no place left behind." This report details 20

  2. Tbx20 acts upstream of Wnt signaling to regulate endocardial cushion formation and valve remodeling during mouse cardiogenesis

    PubMed Central

    Cai, Xiaoqiang; Zhang, Weijia; Hu, Jun; Zhang, Lu; Sultana, Nishat; Wu, Bingruo; Cai, Weibin; Zhou, Bin; Cai, Chen-Leng

    2013-01-01

    Cardiac valves are essential to direct forward blood flow through the cardiac chambers efficiently. Congenital valvular defects are prevalent among newborns and can cause an immediate threat to survival as well as long-term morbidity. Valve leaflet formation is a rigorously programmed process consisting of endocardial epithelial-mesenchymal transformation (EMT), mesenchymal cell proliferation, valve elongation and remodeling. Currently, little is known about the coordination of the diverse signals that regulate endocardial cushion development and valve elongation. Here, we report that the T-box transcription factor Tbx20 is expressed in the developing endocardial cushions and valves throughout heart development. Ablation of Tbx20 in endocardial cells causes severe valve elongation defects and impaired cardiac function in mice. Our study reveals that endocardial Tbx20 is crucial for valve endocardial cell proliferation and extracellular matrix development, but is not required for initiation of EMT. Elimination of Tbx20 also causes aberrant Wnt/?-catenin signaling in the endocardial cushions. In addition, Tbx20 regulates Lef1, a key transcriptional mediator for Wnt/?-catenin signaling, in this developmental process. Our study suggests a model in which Tbx20 regulates the Wnt pathway to direct endocardial cushion maturation and valve elongation, and provides new insights into the etiology of valve defects in humans. PMID:23824573

  3. Transportation and Air Quality

    MedlinePLUS

    ... protects public health and the environment by regulating air pollution from motor vehicles, engines, and the fuels used ... Overview: Pollutants and Programs Information on how much air pollution, air toxics, and greenhouse gases are emitted by ...

  4. Evaluation of vehicle emission inventories for carbon monoxide and nitrogen oxides for Bogot, Buenos Aires, Santiago, and So Paulo

    NASA Astrophysics Data System (ADS)

    Gallardo, Laura; Escribano, Jernimo; Dawidowski, Laura; Rojas, Nstor; de Ftima Andrade, Maria; Osses, Mauricio

    2012-02-01

    We use concurrent morning peak observations of carbon monoxide (CO) and nitrogen oxides (NO x) to evaluate mobile emissions estimates for CO and NO x at Bogot (Colombia), Buenos Aires (Argentina), Santiago (Chile) and So Paulo (Brazil). In all cities, molar ratios of CO to NO x decrease over the last 10-15 years. These ratios are not captured by available inventories. Comparison among inventories suggests that major uncertainties are linked to inadequate emission factors for CO and inadequate activity data for NO x. These results, in combination with previous studies, suggest that current NO x emissions are overestimated by a factor of up to 3 in Santiago and So Paulo, and Buenos Aires shows a slight overestimate by 20%. In the case of Bogot we suspect that the current CO emission inventory is overestimated. Available observations provide valuable information, as exemplified hereby, but more careful attention must be paid to calibration and continuity of the stations.

  5. A ballistic investigation of the aerodynamic characteristics of a blunt vehicle at hypersonic speeds in carbon dioxide and air

    NASA Technical Reports Server (NTRS)

    Packard, James D.; Griffith, Wayland C.; Yates, Leslie A.; Strawa, Anthony W.

    1992-01-01

    Missions to Mars require the successful development of aerobraking technology, and therefore a blunt cone representative of aerobrake shapes is investigated. Ballistic tests of the Pioneer Venus configuration are conducted in carbon dioxide and air at Mach numbers from 7 to 20 and Reynolds numbers from 0.1 x 10 exp 5 to 4 x 10 exp 6. Experimental results show that for defined conditions aerodynamic research can be conducted in air rather than carbon dioxide, providing savings in time and money. In addition, the results offer a prediction of flight aerodynamics during entry into the Martian atmosphere. Also discussed is a comparison of results from two data-reduction techniques showing that a five-degree-of-freedom routine employing weighted least-squares with differential corrections analyzes ballistic data more accurately.

  6. Computer graphic of Lockheed Martin X-33 Reusable Launch Vehicle (RLV) mounted on NASA 747 ferry air

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is an artist's conception of the NASA/Lockheed Martin X-33 Advanced Technology Demonstrator being carried on the back of the 747 Shuttle Carrier Aircraft. This was a concept for moving the X-33 from its landing site back to NASA's Dryden Flight Research Center, Edwards, California. The X-33 was a technology demonstrator vehicle for the Reusable Launch Vehicle (RLV). The RLV technology program was a cooperative agreement between NASA and industry. The goal of the RLV technology program was to enable significant reductions in the cost of access to space, and to promote the creation and delivery of new space services and other activities that will improve U.S. economic competitiveness. NASA Headquarter's Office of Space Access and Technology oversaw the RLV program, which was being managed by the RLV Office at NASA's Marshall Space Flight Center, located in Huntsville, Alabama. Responsibilities of other NASA Centers included: Johnson Space Center, Houston, Texas, guidance navigation and control technology, manned space systems, and health technology; Ames Research Center, Mountain View, CA., thermal protection system testing; Langley Research Center, Langley, Virginia, wind tunnel testing and aerodynamic analysis; and Kennedy Space Center, Florida, RLV operations and health management. Lockheed Martin's industry partners in the X-33 program are: Astronautics, Inc., Denver, Colorado, and Huntsville, Alabama; Engineering & Science Services, Houston, Texas; Manned Space Systems, New Orleans, LA; Sanders, Nashua, NH; and Space Operations, Titusville, Florida. Other industry partners are: Rocketdyne, Canoga Park, California; Allied Signal Aerospace, Teterboro, NJ; Rohr, Inc., Chula Vista, California; and Sverdrup Inc., St. Louis, Missouri.

  7. Comparison of cotton and acrylic socks using a generic cushion sole design for runners.

    PubMed

    Herring, K M; Richie, D H

    1993-09-01

    A longitudinal single-blind study was conducted to test the friction blister prevention properties of synthetic acrylic socks in a generic construction. This study serves as a comparison with the authors' previous work comparing acrylic and cotton socks in a patented padded construction. Twenty-seven long-distance runners provided data regarding dampness, temperature, friction blister incidence, severity, and size. Two different socks were tested; each was identical in every aspect of construction except the fiber content. One test sock was composed of 100% synthetic acrylic fibers, and the other was composed of 100% natural cotton fibers. These results were unsuccessful at demonstrating any superiority of cotton or acrylic fibers when knitting produced a generic "cushion sole" sock. The superiority of acrylic fibers has thus far been demonstrated only when sock knitting provides adequate anatomical padding [corrected]. PMID:8289142

  8. Polymeric capsule-cushioned leukocyte cell membrane vesicles as a biomimetic delivery platform.

    PubMed

    Gao, Changyong; Wu, Zhiguang; Lin, Zhihua; Lin, Xiankun; He, Qiang

    2016-02-14

    We report a biomimetic delivery of microsized capsule-cushioned leukocyte membrane vesicles (CLMVs) through the conversion of freshly reassembled leukocyte membrane vesicles (LMVs), including membrane lipids and membrane-bound proteins onto the surface of layer-by-layer assembled polymeric multilayer microcapsules. The leukocyte membrane coating was verified by using electron microscopy, a quartz crystal microbalance, dynamic light scattering, and confocal laser scanning microscopy. The resulting CLMVs have the ability to effectively evade clearance by the immune system and thus prolong the circulation time in mice. Moreover, we also show that the right-side-out leukocyte membrane coating can distinctly improve the accumulation of capsules in tumor sites through the molecular recognition of membrane-bound proteins of CLMVs with those of tumor cells in vitro and in vivo. The natural cell membrane camouflaged polymeric multilayer capsules with the immunosuppressive and tumor-recognition functionalities of natural leukocytes provide a new biomimetic delivery platform for disease therapy. PMID:26804725

  9. Endocardial Cushion Morphogenesis and Coronary Vessel Development Require Chicken Ovalbumin Upstream Promoter-Transcription Factor II

    PubMed Central

    Lin, Fu-Jung; You, Li-Ru; Yu, Cheng-Tai; Hsu, Wen-Hsin; Tsai, Ming-Jer; Tsai, Sophia Y.

    2013-01-01

    Objective Septal defects and coronary vessel anomalies are common congenital heart defects, yet their ontogeny and the underlying genetic mechanisms are not well understood. Here, we investigated the role of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, NR2F2) in cardiac organogenesis. Methods and Results We analyzed embryos deficient in COUP-TFII and observed a spectrum of cardiac defects, including atrioventricular septal defect, thin-walled myocardium, and abnormal coronary morphogenesis. We show by expression analysis that COUP-TFII is expressed in the endocardium and the epicardium but not in the myocardium of the ventricle. Using endothelial-specific COUP-TFII mutants and molecular approaches, we show that COUP-TFII deficiency resulted in endocardial cushion hypoplasia. This was attributed to the reduced growth and survival of atrioventricular cushion mesenchymal cells and defective epithelial-mesenchymal transformation (EMT) in the underlying endocardium. In addition, the endocardial EMT defect was accompanied by downregulation of Snai1, one of the master regulators of EMT, and upregulation of vascular endothelial-cadherin. Furthermore, we show that although COUP-TFII does not play a major role in the formation of epicardial cell cysts, it is critically important for the formation of epicardium. Ablation of COUP-TFII impairs epicardial EMT and coronary plexus formation. Conclusion Our results reveal that COUP-TFII plays cell-autonomous roles in the endocardium and the epicardium for endocardial and epicardial EMT, which are required for proper valve and coronary vessel formation during heart development. PMID:22962329

  10. Direct compression of cushion-layered ethyl cellulose-coated extended release pellets into rapidly disintegrating tablets without changes in the release profile.

    PubMed

    Hosseini, Armin; Krber, Martin; Bodmeier, Roland

    2013-12-01

    The aim of this study was to develop and optimize a segregation-free ethyl cellulose-coated extended release multiparticulate formulation to be compressed into tablets without affecting the drug release. Standard tableting excipients (e.g., microcrystalline cellulose, lactose or sorbitol) were layered onto ethyl cellulose-coated propranolol hydrochloride pellets to form a cushion layer in order to eliminate segregation problems normally resulting from particle size difference between coated pellets and excipient powders and second to protect the integrity of the brittle ethyl cellulose coating during compression. The disintegration behavior of the tablets depended strongly on the composition of the cushion layer. Rapid tablet disintegration was obtained with microcrystalline cellulose and the disintegrant sodium croscarmellose. However, the drug release from these cushion-layered pellets still increased upon compression. Incorporation of a glidant into the cushion layer or between the cushion layer and the ethyl cellulose coating reduced the compression effect on drug release markedly. Glidant-containing formulations showed a delayed deformation and damage of the ethyl cellulose-coated pellet upon mechanical stress. In summary, cushion layer based on microcrystalline cellulose facilitated segregation-free compression of a highly compression-sensitive extended release ethyl cellulose-coated pellets into fast-disintegrating and hard tablets without compromising the release properties of the multiparticulates. Directly compressible cushion-layered pellets protected the pellet coating significantly better from damages during tabletting when compared to the conventional compression of blends of coated pellets and excipient powders. PMID:23892153

  11. 40 CFR 86.1724-01 - Emission data vehicle selection.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... vehicles certified to the SFTP exhaust emission standards, if air conditioning is projected to be available... which have air conditioning available and would require that any vehicle selected under this section has air conditioning installed and operational....

  12. 40 CFR 86.1724-01 - Emission data vehicle selection.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vehicles certified to the SFTP exhaust emission standards, if air conditioning is projected to be available... which have air conditioning available and would require that any vehicle selected under this section has air conditioning installed and operational....

  13. 40 CFR 86.1724-01 - Emission data vehicle selection.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vehicles certified to the SFTP exhaust emission standards, if air conditioning is projected to be available... which have air conditioning available and would require that any vehicle selected under this section has air conditioning installed and operational....

  14. Kinematics and Shoulder Belt Position of Child Rear Seat Passengers during Vehicle Maneuvers

    PubMed Central

    Bohman, Katarina; Stockman, Isabelle; Jakobsson, Lotta; Osvalder, Anna-Lisa; Bostrom, Ola; Arbogast, Kristy B.

    2011-01-01

    Head impact to the seat back has been identified as one important injury causation scenario for seat belt restrained, head-injured children and previous research highlighted vehicle maneuvers prior to impact as possible contributing factors. The aim was to quantify kinematics of child occupants during swerving maneuvers focusing on the childs lateral movement and seat belt position relative to the childs shoulder. A study was conducted on a closed-circuit test track with 16 children aged 412, restrained in the rear seat of a modern passenger vehicle. A professional driving instructor drove at 50 km/h making sharp turns in a repeatable fashion, resulting in inboard motion of the children. The children were exposed to two turns in each of two restraint systems. Shorter children were on a booster or highback booster cushion. The taller children were seated on a booster cushion or with only a lap and shoulder seat belt. Four film cameras were fixed in the vehicle monitoring the child. Vehicle data were also collected. The seat belt slipped off the shoulder in 1 of 5 turns, varying by age and restraint type. Among shorter children, the belt slipped off in a majority of turns when seated on a booster cushion while the belt remained on the shoulder when seated on the highback booster cushion. Among taller children, the shoulder belt moved far laterally on the shoulder in half of the turns. This data provides valuable knowledge on possible pre-impact postures of children as a result of vehicle swerving maneuvers for a variety of restraint systems. PMID:22105379

  15. Launch vehicle effluent measurements during the May 12, 1977, Titan 3 launch at Air Force Eastern Test Range

    NASA Technical Reports Server (NTRS)

    Gregory, G. L.; Bendura, R. J.; Woods, D. C.

    1979-01-01

    Airborne effluent measurements and cloud physical behavior for the May 21, 1977, Titan 3 launch from the Air Force Eastern Test Range, Fla. are presented. The monitoring program included airborne effluent measurements in situ in the launch cloud, visible and infrared photography of cloud growth and physical behavior, and limited surface collection of rain samples. Airborne effluent measurements included concentrations of HCl, NO, NOx, and aerosols as a function of time in the exhaust cloud. For the first time in situ particulate mass concentration and aerosol number density were measured as a function of time and size in the size range of 0.05 to 25 micro meters diameter. Measurement results were similar to those of earlier launch monitorings. Maximum HCl and NOx concentrations ranged from 10 ppm and 500 ppb, respectively, several minutes after launch to about 1 ppm and 100 ppb at 45 minutes after launch.

  16. A probabilistic and multi-objective conceptual design methodology for the evaluation of thermal management systems on air-breathing hypersonic vehicles

    NASA Astrophysics Data System (ADS)

    Ordaz, Irian

    This thesis addresses the challenges associated with thermal management systems (TMS) evaluation and selection in the conceptual design of hypersonic, air-breathing vehicles with sustained cruise. The proposed methodology identifies analysis tools and techniques which allow the proper investigation of the design space for various thermal management technologies. The design space exploration environment and alternative multi-objective decision making technique defined as Pareto-based Joint Probability Decision Making (PJPDM) is based on the approximation of 3-D Pareto frontiers and probabilistic technology effectiveness maps. These are generated through the evaluation of a Pareto Fitness function and Monte Carlo analysis. In contrast to Joint Probability Decision Making (JPDM), the proposed PJPDM technique does not require preemptive knowledge of weighting factors for competing objectives or goal constraints which can introduce bias into the final solution. Preemptive bias in a complex problem can degrade the overall capabilities of the final design. The implementation of PJPDM in this thesis eliminates the need for the numerical optimizer which is required with JPDM in order to improve upon a solution. In addition, a physics-based formulation is presented for the quantification of TMS safety effectiveness corresponding to debris impact/damage and how it can be applied towards risk mitigation. Lastly, a formulation loosely based on non-preemptive Goal Programming with equal weighted deviations is provided for the resolution of the inverse design space. This key step helps link vehicle capabilities to TMS technology subsystems in a top-down design approach. The methodology provides the designer more knowledge up front to help make proper engineering decisions and assumptions in the conceptual design phase regarding which technologies show greatest promise, and how to guide future technology research.

  17. An adaptive dual-optimal path-planning technique for unmanned air vehicles with application to solar-regenerative high altitude long endurance flight

    NASA Astrophysics Data System (ADS)

    Whitfield, Clifford A.

    2009-12-01

    A multi-objective technique for Unmanned Air Vehicle (UAV) path and trajectory autonomy generation, through task allocation and sensor fusion has been developed. The Dual-Optimal Path-Planning (D-O.P-P.) Technique generates on-line adaptive flight paths for UAVs based on available flight windows and environmental influenced objectives. The environmental influenced optimal condition, known as the driver' determines the condition, within a downstream virtual window of possible vehicle destinations and orientation built from the UAV kinematics. The intermittent results are pursued by a dynamic optimization technique to determine the flight path. This sequential optimization technique is a multi-objective optimization procedure consisting of two goals, without requiring additional information to combine the conflicting objectives into a single-objective. An example case-study and additional applications are developed and the results are discussed; including the application to the field of Solar Regenerative (SR) High Altitude Long Endurance (HALE) UAV flight. Harnessing solar energy has recently been adapted for use on high altitude UAV platforms. An aircraft that uses solar panels and powered by the sun during the day and through the night by SR systems, in principle could sustain flight for weeks or months. The requirements and limitations of solar powered flight were determined. The SR-HALE UAV platform geometry and flight characteristics were selected from an existing aircraft that has demonstrated the capability for sustained flight through flight tests. The goals were to maintain continual Situational Awareness (SA) over a case-study selected Area of Interest (AOI) and existing UAV power and surveillance systems. This was done for still wind and constant wind conditions at altitude along with variations in latitude. The characteristics of solar flux and the dependence on the surface location and orientation were established along with fixed flight maneuvers for the SR-HALE UAV. A sustained turn circle flight pattern, common for vehicles in loiter was selected as a baseline for comparisons. The objectives of the D-O.P-P. Technique for SR-HALE flight were to determine the minimum required power flight paths to the predetermined location and orientation for obtaining maximum solar flux established by the 'driver.' The on-line path generation technique prolonged the flight duration, over the baseline by approximately two months for a year of flight over the case-study AOI. This prolonged flight was consistent for all latitude locations, including two months of available flight at 60 degree latitude---where sustained turn baseline flight was no longer capable. This was possible by increasing the total solar power by as much as 28% while decreasing the averaged power required for flight.

  18. Magnitude and value of electric vehicle emissions reductions for six driving cycles in four US cities with varying air quality problems

    SciTech Connect

    Wang, Q. ); Santini, D.L. )

    1992-01-01

    The emissions of logically competing mid-1990 gasoline vehicles (GVs) and electric vehicles (EVs) are estimated as if the vehicles were driven in the same pattern of driving. Six different driving cycles are evaluated, ranging in speed from 7 to 49 miles per hour (mph). These steps are repeated using specifics of fuel composition, electric power mix, and environmental conditions applicable to Chicago, Denver, Los Angeles, and New York in the month of July. The year 2000 emissions differences for each of four regulated pollutants - HC, CO, NO[sub x,] SO[sub x] - are estimated. CO[sub 2] emissions are also estimated. With use of EVs, HC and CO emissions are consistently lowered by 98% or more. CO[sub 2] emissions reductions are uniformly large at low speed, but variable at high speed. It is found that initially introduced EVs could achieve 100% emission reductions in Chicago by using off-peak power from nuclear power plants for EV electricity generation. Emissions reductions occur for all combinations in Los Angeles, and for most combinations in New York, excepting SO[sub x]. NO[sub x] emissions are reduced in all four cities. An avoided cost'' value for each regulated pollutant is estimated for each of the cities. The values for each city depend on severity of air quality violations. It is estimated that the emissions reduction value of EVs driven an average of one and one half hours per day in Los Angeles ranges from $1050 to $3,900; $590 to $2100 in New York; $270 to $1200 in Chicago, and $330 to $1250 in Denver (1989$). Assuming a range of about 100 miles in congested conditions with speeds of 10 mph or less, the estimates range from $3600 to $13300 for Los Angeles; $2004 to $7200 for New York; $930 to $2930 for Chicago; and $1120 to $4290 for Denver. Low estimates are obtained using EPA's draft Mobile5 model for GV emissions, high values by using California's EMFAC7EP-SCF1 model. The dollar value benefit estimates include no economic value.

  19. Magnitude and value of electric vehicle emissions reductions for six driving cycles in four US cities with varying air quality problems

    SciTech Connect

    Wang, Q.; Santini, D.L.

    1992-12-31

    The emissions of logically competing mid-1990 gasoline vehicles (GVs) and electric vehicles (EVs) are estimated as if the vehicles were driven in the same pattern of driving. Six different driving cycles are evaluated, ranging in speed from 7 to 49 miles per hour (mph). These steps are repeated using specifics of fuel composition, electric power mix, and environmental conditions applicable to Chicago, Denver, Los Angeles, and New York in the month of July. The year 2000 emissions differences for each of four regulated pollutants - HC, CO, NO{sub x,} SO{sub x} - are estimated. CO{sub 2} emissions are also estimated. With use of EVs, HC and CO emissions are consistently lowered by 98% or more. CO{sub 2} emissions reductions are uniformly large at low speed, but variable at high speed. It is found that initially introduced EVs could achieve 100% emission reductions in Chicago by using off-peak power from nuclear power plants for EV electricity generation. Emissions reductions occur for all combinations in Los Angeles, and for most combinations in New York, excepting SO{sub x}. NO{sub x} emissions are reduced in all four cities. An ``avoided cost`` value for each regulated pollutant is estimated for each of the cities. The values for each city depend on severity of air quality violations. It is estimated that the emissions reduction value of EVs driven an average of one and one half hours per day in Los Angeles ranges from $1050 to $3,900; $590 to $2100 in New York; $270 to $1200 in Chicago, and $330 to $1250 in Denver (1989$). Assuming a range of about 100 miles in congested conditions with speeds of 10 mph or less, the estimates range from $3600 to $13300 for Los Angeles; $2004 to $7200 for New York; $930 to $2930 for Chicago; and $1120 to $4290 for Denver. Low estimates are obtained using EPA`s draft Mobile5 model for GV emissions, high values by using California`s EMFAC7EP-SCF1 model. The dollar value benefit estimates include no economic value.

  20. Testing the Stress-Gradient Hypothesis at the Roof of the World: Effects of the Cushion Plant Thylacospermum caespitosum on Species Assemblages

    PubMed Central

    Dvorský, Miroslav; Doležal, Jiří; Kopecký, Martin; Chlumská, Zuzana; Janatková, Kateřina; Altman, Jan; de Bello, Francesco; Řeháková, Klára

    2013-01-01

    Many cushion plants ameliorate the harsh environment they inhabit in alpine ecosystems and act as nurse plants, with significantly more species growing within their canopy than outside. These facilitative interactions seem to increase with the abiotic stress, thus supporting the stress-gradient hypothesis. We tested this prediction by exploring the association pattern of vascular plants with the dominant cushion plant Thylacospermum caespitosum (Caryophyllaceae) in the arid Trans-Himalaya, where vascular plants occur at one of the highest worldwide elevational limits. We compared plant composition between 1112 pair-plots placed both inside cushions and in surrounding open areas, in communities from cold steppes to subnival zones along two elevational gradients (East Karakoram: 4850–5250 m and Little Tibet: 5350–5850 m). We used PERMANOVA to assess differences in species composition, Friedman-based permutation tests to determine individual species habitat preferences, species-area curves to assess whether interactions are size-dependent and competitive intensity and importance indices to evaluate plant-plant interactions. No indications for net facilitation were found along the elevation gradients. The open areas were not only richer in species, but not a single species preferred to grow exclusively inside cushions, while 39–60% of 56 species detected had a significant preference for the habitat outside cushions. Across the entire elevation range of T. caespitosum, the number and abundance of species were greater outside cushions, suggesting that competitive rather than facilitative interactions prevail. This was supported by lower soil nutrient contents inside cushions, indicating a resource preemption, and little thermal amelioration at the extreme end of the elevational gradient. We attribute the negative associations to competition for limited resources, a strong environmental filter in arid high-mountain environment selecting the stress-tolerant species that do not rely on help from other plants during their life cycle and to the fact the cushions do not provide a better microhabitat to grow in. PMID:23326446