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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 ACV’s 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 ACV’s 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. 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.

  13. 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.

  14. 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…

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Air cushion landing system stability study

    NASA Astrophysics Data System (ADS)

    Burton, T. D.

    1981-02-01

    An analysis of an inelastic ACLS plunge mode dynamic model is presented. The ACLS has unrestrained side elements and frozen end elements. The model exhibits unstable behavior at certain operating conditions for which the side elements are in contact with the ground. A linear analysis showed this instability to be due mainly to the altitude sensitivities of the cushion to atmosphere airflows and the attendant influence on the dynamic pressure forces on the vehicle. The model instability can be alleviated by isolating side and end elements so that they are all unrestrained and by simultaneously venting the air cushion directly to atmosphere.

  2. Air cushion craft development, first revision

    NASA Astrophysics Data System (ADS)

    Mantle, P. J.

    1980-01-01

    The development of air cushion craft from their inception to the present day is described. Both aerostatic craft known as air cushion vehicles and surface effect ships as well as aerodynamic craft such as wing-in-ground effect vehicles are covered. The various available theories, empirical laws, and experimental data were brought together and expressed in unified form. Emphasis is given to reducing the data and analysis to their simplest forms for easy understanding and isolation of fundamental parameters. Currently operational craft, those still in their construction jigs, or in some cases those still on the drawing board are assessed and compared to the basic theories to give a measure of the state-of-the-art. Such topics as performance, propulsion, ride quality, and high speed aerodynamic craft are included.

  3. 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.

  4. 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.

  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. Injuries in children associated with trampolinelike air cushions.

    PubMed

    Olsen, P A

    1988-01-01

    During a 7-month period, we registered 112 children who had been injured in an amusement park. Despite the large number of other playground apparatuses, 78 injuries were associated with jumping on three giant air cushion trampolinelike apparatuses. Moreover, the air cushions caused a significantly larger number of severe and moderate injuries than did other apparatuses (p less than 0.01). Thirty-one percent of the injuries were fractures or growth plate lesions. Seventy percent of the children explained that they had either been pushed or had lost their balance because of the constantly changing rhythm of the canvas. We therefore warn against this trampolinelike apparatus.

  7. 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.

  8. 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.

  9. An alternating pressure sequence proposal for an air-cell cushion for preventing pressure ulcers.

    PubMed

    Arias, Sandra; Cardiel, Eladio; Rogeli, Pablo; Mori, Taketoshi; Nakagami, Gojiro; Noguchi, Hiroshi; Sanada, Hiromi

    2014-01-01

    The distribution and release of pressure on ischial regions are two important parameters for evaluating the effectiveness of a cushion; especially the release of pressure over time on ischial tuberosities, which is significant for preventing pressure ulcers. The aim of this work is to evaluate the effect on interface pressure through the application of a proposed alternating pressure sequence for an air-cell cushion. Six healthy volunteers were asked to sit on the air cell cushion, in static and alternating modes, as well as on a typical foam cushion for 12 minutes. Interface pressure was monitored with a matrix sensor system. Interface pressure values on ischial tuberosities, user contact area and pressure distribution were analyzed. Results showed that IP on IT tends to increase in both foam and static cushions, while in alternating cushion IP on IT tends to decrease. User contact area was significantly larger in alternating cushion than in static or foam cushions. Moreover, there is a better pressure re-distribution with alternating cushion than with the other cushions. The goal of the alternating sequence is to redistribute pressure and stimulate the ischial regions in order to promote blood flow and prevent pressure occurring in wheelchair users.

  10. 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.

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

    DOEpatents

    Vaughn, Mark R.; Constantineau, Edward J.; Groves, Gordon E.

    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.

  12. 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.

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

    DOEpatents

    Stevens, Wayne W.; Solbrig, Charles W.

    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.

  14. 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.

  15. An analysis of contact stiffness between a finger and an object when wearing an air-cushioned glove: the effects of the air pressure.

    PubMed

    Wu, John Z; Wimer, Bryan M; Welcome, Daniel E; Dong, Ren G

    2012-04-01

    Air-cushioned gloves have the advantages of lighter weight, lower cost, and unique mechanical performance, compared to gloves made of conventional engineering materials. The goal of this study is to analyze the contact interaction between fingers and object when wearing an air-cushioned glove. The contact interactions between the the fingertip and air bubbles, which is considered as a cell of a typical air-cushioned glove, has been analyzed theoretically. Two-dimensional finite element models were developed for the analysis. The fingertip model was assumed to be composed of skin layers, subcutaneous tissue, bone, and nail. The air bubbles were modeled as air sealed in the container of nonelastic membrane. We simulated two common scenarios: a fingertip in contact with one single air bubble and with two air cushion bubbles simultaneously. Our simulation results indicated that the internal air pressure can modulate the fingertip-object contact characteristics. The contact stiffness reaches a minimum when the initial air pressure is equal to 1.3 and 1.05 times of the atmosphere pressure for the single air bubble and the double air bubble contact, respectively. Furthermore, the simulation results indicate that the double air bubble contact will result in smaller volumetric tissue strain than the single air bubble contact for the same force.

  16. 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.

  17. 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.

  18. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    NASA Astrophysics Data System (ADS)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. System safety engineering in the development of advanced surface transportation vehicles

    NASA Technical Reports Server (NTRS)

    Arnzen, H. E.

    1971-01-01

    Applications of system safety engineering to the development of advanced surface transportation vehicles are described. As a pertinent example, the paper describes a safety engineering efforts tailored to the particular design and test requirements of the Tracked Air Cushion Research Vehicle (TACRV). The test results obtained from this unique research vehicle provide significant design data directly applicable to the development of future tracked air cushion vehicles that will carry passengers in comfort and safety at speeds up to 300 miles per hour.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Aluminum air battery for electric vehicle propulsion

    SciTech Connect

    Cooper, J.F.; Homsy, R.V.; Landrum, J.H.

    1980-01-01

    The status of aluminum-air battery development and the use of aluminum as a recyclable electrochemical fuel are discussed. The battery combines high specific energy (above 300 Wh/kg) and specific power (150 to 200 W/kg) with the capability of rapid refueling by addition of reactants. The objective is a commercially-feasible, general-purpose electric vehicle. Progress is reported in the scale-up of aluminum-air single cells to the automotive scale (0.1 m/sup 2/-anodes) and in the development of a hydrargillite crystallizer, which is required to control electrolyte composition. Major technical problems and development strategy are discussed. The total cost and energy required to produce aluminum, and projected consumption by electric vehicles indicates that the aluminum-air powered electric vehicle is potentially competitive with advanced automobiles using synthetic liquid fuels.

  12. Clean fuel vehicles: The air pollution solution

    SciTech Connect

    Meotti, M.P.

    1995-11-01

    Clean fuels for cars and trucks can do more for air quality, and do it sooner, than any other alternative on the drawing boards today. In much of the country, vehicles are the single biggest cause of air pollution. It`s not the industrial smoke stacks, but the tail pipes on cars that foul the air. Ninety percent of the carbon monoxide, 50% of the volatile organic compounds, and 40% of the ozone in metropolitan areas come from motor vehicles. Many state and local government officials are pursuing vehicle emission inspection, high occupancy vehicle lanes, and carpooling programs to reduce auto pollution. These efforts are valuable and should be continued. But clean fuels can quickly reduce auto emissions at a much lower cost. Alternative fuel vehicles produce fewer emissions, are much less dependent on foreign sources, and have the potential to create new jobs. One alternative fuel, natural gas, emits no particulates, 90% less carbon monoxide, and 85% fewer of the gases that form ozone.

  13. Biofuels, vehicle emissions, and urban air quality.

    PubMed

    Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

    2016-07-18

    Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel. PMID:27112132

  14. Biofuels, vehicle emissions, and urban air quality.

    PubMed

    Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

    2016-07-18

    Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel.

  15. 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.

  16. Aluminum-air batteries for vehicles

    SciTech Connect

    Behrin, E.; Cooper, J.F.

    1981-02-23

    The aluminum-air battery is an advanced electrochemical energy source in the early stages of development. The battery is potentially capable of providing an electric vehicle with the range, acceleration, and rapid refueling capability of today's automobile. The Lawrence Livermore National Laboratory leads this DOE-funded program with a major part of the research being conducted by industrial laboratories. Peak cell energy yields above 4 kWh/kg-Al and peak power densities greater than 6 kW/m/sup 2/ have been demonstrated in single cells. Projected energy density and power density of a complete vehicle battery are greater than 300 Wh/kg and 150 W/kg. The concept, technical status, development strategy, and the results of battery and vehicle analyses are reviewed.

  17. 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.

  18. 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.

  19. The perfect ash-storm: large-scale Pyroclastic Density Current experiments reveal highly mobile, self-fluidising and air-cushioned flow transport regime

    NASA Astrophysics Data System (ADS)

    Lube, G.; Cronin, S. J.; Breard, E.; Valentine, G.; Bursik, M. I.; Hort, M. K.; Freundt, A.

    2013-12-01

    -solids concentrations of 1-5 vol%. The front shows a brief phase of negative pore pressure due to the entrainment and upward elutriation of ambient air inside this front. It is immediately followed by the fine-ash rich and highly impermeable main flow body. Passage of the flow body is accompanied by strongly increasing pore-pressures of 1-3 kPa that almost fully supports the weight of the entire underflow - depicting flow-induced fluidisation of the main flow part. The remainder of the flow body shows further increases in pore-pressure aside with strong reductions in flow mass. This suggests the occurrence of zones of air-cushions forming at the base of the underflow that largely aid its inviscid runout. This sequence is repeated during arrival and passage of up to three more flow pulses. The low-permeability deposits maintain high internal gas pore pressures for several minutes after emplacement, before sudden deaeration, settling and gas loss is caused by fracturing. Flow-induced fluidisation and basal air-cushioning provide key processes behind the enigmatic long runout behaviour of dense PDCs.

  20. Air cushioning in droplet impact. I. Dynamics of thin films studied by dual wavelength reflection interference microscopy

    NASA Astrophysics Data System (ADS)

    de Ruiter, Jolet; Mugele, Frieder; van den Ende, Dirk

    2015-01-01

    When a liquid droplet impacts on a solid surface, it not only deforms substantially but also an air film develops between the droplet and the surface. This thin air film—as well as other transparent films—can be characterized by reflection interference microscopy. Even for weakly reflecting interfaces, relative thickness variations of the order of tens of nanometers are easily detected, yet the absolute thickness is generally known only up to an additive constant which is a multiple of half of the wavelength. Here, we present an optical setup for measuring the absolute film thickness and its spatial and temporal behavior using a combination of a standard Hg lamp, an optical microscope, and three synchronized high-speed cameras to detect conventional side-view images as well as interferometric bottom view images at two different wavelengths. The combination of a dual wavelength approach with the finite coherence length set by the broad bandwidth of the optical filters allows for measuring the absolute thickness of transient air films with a spatial resolution better than 30 nm at 50 μs time resolution with a maximum detectable film thickness of approximately 8 μm. This technique will be exploited in Part II to characterize the air film evolution during low velocity droplet impacts.

  1. Characterization of volatile organic chemical emissions from carpet cushions

    SciTech Connect

    Schaeffer, V.H.; Bhooshan, B.; Chen, S.B.; Sonenthal, J.S.; Hodgson, A.T.

    1996-09-01

    The U.S. Consumer Product Safety Commission is investigating chemical emissions from carpet systems in order to determine whether the emissions may be responsible for the numerous health complaints associated with carpet installation. As part of this effort, a study was conducted to identify and quantify volatile organic compounds (VOCs) released into the air by five major product types of new carpet cushions. Cushion samples were tested in small-volume dynamic chambers over a six-hour exposure period. Airborne VOCs collected on multisorbent samplers were identified using sensitive gas chromatography/mass spectrometry. A separate chamber method was developed to screen polyurethane cushions for emissions of toluene diisocyanates (TDI). Over 100 VOCs, spanning a broad range of chemical classes, were emitted from 17 carpet cushions. The pattern of emitted VOCs varied between and among product types, which reflects probable differences in manufacturing processes and ingredients. No significant quantities of TDI or formaldehyde were released by any cushions. Emission profiles were characterized for total VOCs and for the predominant individual VOCs. As a group, the synthetic fiber cushion samples emitted the lowest quantities of VOCs. Cushion samples purchased from carpet retailers released lesser amounts of VOCs than samples of the same cushion types obtained directly from the manufacturing mills. 11 refs., 2 figs., 3 tabs.

  2. Zinc air battery development for electric vehicles

    NASA Astrophysics Data System (ADS)

    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 (greater than 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high resistance failure of the cell. The Phase 1 program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/sq cm. By the end of the Phase 1 program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase 2 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.

  3. 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.

  4. 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.

  5. 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.

  6. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.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. 8 figs., 2 tabs.

  7. 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.

  8. 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

  9. 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

  10. Interior Beale Air Force Base, Perimeter Acquisition Vehicle Entry ...

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

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

  11. 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

  12. 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.

  13. 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

  14. 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

  15. Design and analysis of a gyroscopically controlled micro air vehicle

    NASA Astrophysics Data System (ADS)

    Thorne, Christopher Everett

    Much of the current research on micro air vehicle design relies on aerodynamic forces for attitude control. The aerodynamic environment in which micro air vehicles operate is characterized by a low Reynolds number and is not fully understood, resulting in decreased performance and efficiency when compared to large-scale vehicles. In this work, we propose a new rotary-wing micro air vehicle design that utilizes gyroscopic dynamics for attitude control. Unlike traditional micro air vehicles where attitude control moments are generated by aerodynamic control surfaces, the proposed vehicle will leverage the existing angular momentum of its rotating components to generate gyroscopic moments for controlling attitude. We explore this paradigm in an effort to reduce mechanical complexity that is inherent in blade pitch modulation mechanisms such as the swashplate, and to increase agility and possibly even efficiency when compared to state-of-the-art micro vertical-take-off-and-landing vehicles. The evolution of the mechanical design, including the evaluation of three prototypes that explore the use of gyroscopic attitude control, is presented along with a comprehensive dynamic and aerodynamic model of the third prototype. Two controllers that utilize gyroscopic moments are developed and tested in simulation. In addition, several experiments were performed using a VICON motion tracking system and off-board control. These results will also be presented.

  16. 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

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

    PubMed

    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

  18. 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''),...

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. Large lighter-than-air vehicles

    NASA Technical Reports Server (NTRS)

    Mayer, N. J.

    1979-01-01

    The background of experience and the results achieved in building large airships are discussed. Two current applications are identified. These are in heavy vertical lift and in long endurance patrol. The most promising concepts for these missions include hybrid combinations of helicopters and aerostats and more conventional rigid types. These new approaches will require some technology development in aerodynamics and structures, but all vehicles will benefit from application of modern methods and materials.

  4. The aluminum-air battery for electric vehicles - An update

    SciTech Connect

    Not Available

    1980-11-01

    The development of aluminum-air batteries as mechanically rechargeable power sources to be used in electric vehicles is discussed. The chemistry of the aluminum-air battery, which has a potential for providing the range, acceleration and rapid refueling capability of contemporary automobiles and is based on the reaction of aluminum metal with atmospheric oxygen in the presence of an aqueous sodium hydroxide/sodium aluminate electrolyte, is examined, and it is pointed out that the electric vehicle would be practically emissionless. The battery development program at the Lawrence Livermore National Laboratory, which includes evaluations of electrochemical and chemical phenomena, studies of the economics and energy balance of a transportation system based on aluminum, and power cell design and performance analysis, is presented. It is concluded that although difficult problems must be overcome before the technical and economic feasibility of aluminum-air batteries for electric vehicles can be established, projections indicate that the aluminum-air vehicle is potentially competitive with internal combustion vehicles powered by synthetic liquid fuels.

  5. 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.

  6. Electric Vehicle Preparedness - Implementation Approach for Electric Vehicles at Naval Air Station Whidbey Island. Task 4

    SciTech Connect

    Schey, Stephen; Francfort, Jim

    2015-06-01

    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). This study is focused on the Naval Air Station Whidbey Island (NASWI) located in Washington State. 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. In Task 2, daily operational characteristics of vehicles were identified to select vehicles for further monitoring and attachment of data loggers. Task 3 recorded vehicle movements in order to characterize the vehicles’ missions. The results of the data analysis and observations were provided. Individual observations of the selected vehicles provided the basis for recommendations related to PEV adoption, i.e., whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively PEVs) can fulfill the mission requirements. It also provided the basis for recommendations related to placement of PEV charging infrastructure. This report focuses on an implementation plan for the near-term adoption of PEVs into the NASWI fleet.

  7. Unmanned Air Vehicle -Version 1.0

    SciTech Connect

    Fred Oppel, SNL 06134

    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.

  8. 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.

  9. 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.

  10. 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.

  11. Mechanically refuelable zinc/air electric vehicle cells

    SciTech Connect

    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 a 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 in this report focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  12. An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

    SciTech Connect

    Cunningham, C.T.; Roberts, R.S.

    2000-09-12

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  13. 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.

  14. Adaptive path planning algorithm for cooperating unmanned air vehicles

    SciTech Connect

    Cunningham, C T; Roberts, R S

    2001-02-08

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  15. 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.

  16. Powering future vehicles with the refuelable zinc/air battery

    SciTech Connect

    1995-10-01

    A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to 4.0 metric tons, in battery weight from 2.0 to 0.3 metric tons, in battery volume from 0.79 to 0.25 m{sup 3}, and in electricity cost from 5.6 cents per mile to 4.7 cents per mile. The power, however, remains the same.

  17. Episodic air quality impacts of plug-in electric vehicles

    NASA Astrophysics Data System (ADS)

    Razeghi, Ghazal; Carreras-Sospedra, Marc; Brown, Tim; Brouwer, Jack; Dabdub, Donald; Samuelsen, Scott

    2016-07-01

    In this paper, the Spatially and Temporally Resolved Energy and Environment Tool (STREET) is used in conjunction with University of California Irvine - California Institute of Technology (UCI-CIT) atmospheric chemistry and transport model to assess the impact of deploying plug-in electric vehicles and integrating wind energy into the electricity grid on urban air quality. STREET is used to generate emissions profiles associated with transportation and power generation sectors for different future cases. These profiles are then used as inputs to UCI-CIT to assess the impact of each case on urban air quality. The results show an overall improvement in 8-h averaged ozone and 24-h averaged particulate matter concentrations in the South Coast Air Basin (SoCAB) with localized increases in some cases. The most significant reductions occur northeast of the region where baseline concentrations are highest (up to 6 ppb decrease in 8-h-averaged ozone and 6 μg/m3 decrease in 24-h-averaged PM2.5). The results also indicate that, without integration of wind energy into the electricity grid, the temporal vehicle charging profile has very little to no effect on urban air quality. With the addition of wind energy to the grid mix, improvement in air quality is observed while charging at off-peak hours compared to the business as usual scenario.

  18. 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.

  19. 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.

  20. Multi-hole pressure probes to air data system for subsonic small-scale air vehicles

    NASA Astrophysics Data System (ADS)

    Shevchenko, A. M.; Berezin, D. R.; Puzirev, L. N.; Tarasov, A. Z.; Kharitonov, A. M.; Shmakov, A. S.

    2016-10-01

    A brief review of research performed to develop multi-hole probes to measure of aerodynamic angles, dynamic head, and static pressure of a flying vehicle. The basis of these works is the application a well-known classical multi-hole pressure probe technique of measuring of a 3D flow to use in the air data system. Two multi-hole pressure probes with spherical and hemispherical head to air-data system for subsonic small-scale vehicles have been developed. A simple analytical probe model with separation of variables is proposed. The probes were calibrated in the wind tunnel, one of them is in-flight tested.

  1. 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.

  2. 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...

  3. Potential impacts of electric vehicles on air quality in Taiwan.

    PubMed

    Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

    2016-10-01

    The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions.

  4. Potential impacts of electric vehicles on air quality in Taiwan.

    PubMed

    Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

    2016-10-01

    The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions. PMID:27285533

  5. 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.

  6. Conceptual design of flapping-wing micro air vehicles.

    PubMed

    Whitney, J P; Wood, R J

    2012-09-01

    Traditional micro air vehicles (MAVs) are miniature versions of full-scale aircraft from which their design principles closely follow. The first step in aircraft design is the development of a conceptual design, where basic specifications and vehicle size are established. Conceptual design methods do not rely on specific knowledge of the propulsion system, vehicle layout and subsystems; these details are addressed later in the design process. Non-traditional MAV designs based on birds or insects are less common and without well-established conceptual design methods. This paper presents a conceptual design process for hovering flapping-wing vehicles. An energy-based accounting of propulsion and aerodynamics is combined with a one degree-of-freedom dynamic flapping model. Important results include simple analytical expressions for flight endurance and range, predictions for maximum feasible wing size and body mass, and critical design space restrictions resulting from finite wing inertia. A new figure-of-merit for wing structural-inertial efficiency is proposed and used to quantify the performance of real and artificial insect wings. The impact of these results on future flapping-wing MAV designs is discussed in detail. PMID:22498507

  7. 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.

  8. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, James M.; Luna, Daniel A.; Gwinn, Kenneth W.

    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.

  9. Attachment device for an inflatable protective cushion

    DOEpatents

    Nelsen, James M.; Luna, Daniel A.; Gwinn, Kenneth W.

    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.

  10. 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.

  11. 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.

  12. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Optional equipment and air conditioning for test vehicles. For test vehicles selected under §§ 86.1822-01... be expected to influence emissions include, but are not limited to: air conditioning, power steering...) Except for air conditioning, where it is expected that 33 percent or less of a car line, within a...

  13. 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.

  14. 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.

  15. Solar panel driven air purging apparatus for motor vehicles

    SciTech Connect

    Bobier, J.A.; Brown, G.E.

    1992-02-18

    This patent describes improvement in a motor vehicle having an enclosable cabin an internal combustion engine, a battery, an ignition switch having an on position for enabling the internal combustion engine and an off position, an electric motor coupled in driving relationship with an air circulating fan for circulating air through the cabin. The improvement comprises: a solar panel mounted upon the vehicle having a panel output exhibiting variable voltage levels including a peak voltage level and substantially constant current; a power transfer regulator for transferring power form the panel to the motor when enabled, including: energy storage means connectable across the panel output and chargeable by the current to variable charge levels; solid-state switch means connected in energy transfer relationship with the energy storage means and actuable between conducting and non-conducting states when the power transfer regulator is enabled; inductor means connected with the solid-state switch means and connectable with the electric motor for conveying current thereto from the panel and the energy storage means when the solid-state switch means is in the conducting state.

  16. 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.

  17. 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....

  18. 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....

  19. 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....

  20. 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....

  1. 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....

  2. Flexible Wing Base Micro Aerial Vehicles: Micro Air Vehicles (MAVs) for Surveillance and Remote Sensor Delivery

    NASA Technical Reports Server (NTRS)

    Ifju, Peter

    2002-01-01

    Micro Air Vehicles (MAVs) will be developed for tracking individuals, locating terrorist threats, and delivering remote sensors, for surveillance and chemical/biological agent detection. The tasks are: (1) Develop robust MAV platform capable of carrying sensor payload. (2) Develop fully autonomous capabilities for delivery of sensors to remote and distant locations. The current capabilities and accomplishments are: (1) Operational electric (inaudible) 6-inch MAVs with novel flexible wing, providing superior aerodynamic efficiency and control. (2) Vision-based flight stability and control (from on-board cameras).

  3. Feasibility study of applying laminar flow control to an lta vehicle. Final report. [Lighter than air vehicles

    SciTech Connect

    Warner, D.J.; Ozgur, S.A.; Haigh, W.W.

    1980-04-01

    The feasibility of applying laminar boundary-layer control with body shaping to a high altitude, Lighter-Than-Air vehicle was investigated. Solar-radiation-induced surface heating was shown to have a destablizing effect on laminar flow and caused the laminar flow to break down on regions of the vehicle surface exposed to high levels of solar radiation. Aerodynamic drag estimates were made for the vehicle. Surface waviness and roughness criteria for achieving laminar flow were determined.

  4. 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.

  5. Vehicle expectations in air transportation for the year 2000

    NASA Technical Reports Server (NTRS)

    Hearth, D. P.

    1980-01-01

    This paper is intended to provide an overview of the air transportation system for the year 2000 in terms of vehicle expectations. Emphasis is placed on civil air transportation with the time period approached from the standpoint of evolutionary changes for the near term and also with the assumption of more revolutionary changes for the far term. The view along the evolutionary path begins with a historical review of airline market growth and the impact that technologies have had on airplane designs. Projections of the life expectancy of existing, derivative, and new airplanes are examined in terms of their productivity and fuel efficiency in view of the present and projected fuel usage and availability. The factors influencing airline growth are outlined and some views on whether another new generation of subsonic airplanes are in the offing are given along with an assessment of the economic viability of an advanced commercial supersonic transport in terms of its higher speed, higher productivity, and higher fuel usage. With regard to revolutionary changes, major technology breakthroughs are assumed to occur at a specified date. As an example, the impact of a dramatic reduction in skin friction drag is examined in terms of its effect on the airplane configuration, its propulsion systems, it projected fuel usage, and the air transportation system in which it must operate.

  6. A novel zinc-air battery for electric vehicles

    SciTech Connect

    Ross, P.N.

    1995-07-01

    A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12 M KOH saturated or supersaturated with zincate. Single cells as large as 200 cm{sup 2} (1/5 EV design scale) having a capacity of 20 AH have been tested with C/4--C/16 constant current cycling. More extensive and realistic life cycle testing was done with 2 Ah cells, including the Simplified Federal Urban Driving Schedule (SFUDS) cycle. This testing has confirmed that these cells can provide the necessary transient power response required for urban EV applications. The cells achieved an average of 72 SFUDS repetitions (7.2 hrs) per discharge cycle, more than twice the number with a sealed lead acid EV battery in similar testing. The full scale (30 kWh) EV battery design based on these single cell tests indicate an energy density of 90--100 Wh/kg, 60--80 W/kg, and a very low materials cost ($50 per kWh). These results indicate this battery would provide at least twice the vehicle range of a lead acid battery of the same volume at a comparable or even lower materials cost.

  7. 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.

  8. Analysis of aluminum-air battery propulsion systems for passenger vehicles

    SciTech Connect

    Salisbury, J.D.; Behrin, E.

    1980-05-01

    The performance characteristics of three electric-propulsion systems based on the Al-air battery were analyzed and compared to the internal combustion engine (ICE). Battery characteristics projected from late 1979 and early 1980 experimental results were used in the analysis. In this comparison, the engine and fuel systems of a current five-passenger vehicle were conceptually replaced by three Al-air systems: (1) an Al-air battery-only system; (2) an Al-air battery combined with a nickel-zinc secondary battery for power leveling; and (3) an Al-air battery combined with a flywheel power leveler. The resultant vehicles were constrained to have range and acceleration performance equivalent to the ICE-powered vehicle. Performance characteristics such as the average consumption rate of Al metal for the selected drive cycle, vehicle mass, and power system mass were determined for each Al-air propulsion system. Estimates of initial-vehicle and life-cycle costs of Al-air battery-only vehicles indicate that all three systems can achieve performance and operation costs comparable to an ICE vehicle, and that the initial cost of Al-air battery-only vehicles can approach the cost of ICE vehicles but at reduced power levels.

  9. Verification of the dose attenuation of a newly developed vacuum cushion for intensity-modulated radiation therapy of prostate cancer.

    PubMed

    Takakura, Toru; Ito, Yoshiyuki; Higashikawa, Akinori; Nishiyama, Tomohiro; Sakamoto, Takashi

    2016-07-01

    This study measured the dose attenuation of a newly developed vacuum cushion for intensity-modulated radiation therapy (IMRT) of prostate cancer, and verified the effect of dose-correction accuracy in a radiation treatment planning system (RTPS). The new cushion was filled with polystyrene foams inflated 15-fold (Sφ ≒ 1 mm) to reduce contraction caused by air suction and was compared to normal polystyrene foam inflated to 50-fold (Sφ ≒ 2 mm). The dose attenuation at several thicknesses of compression bag filled with normal and low-inflation materials was measured using an ionization chamber; and then the calculated RTPS dose was compared to ionization chamber measurements, while the new cushion was virtually included as region of interest in the calculation area. The dose attenuation rate of the normal cushion was 0.010 %/mm (R (2) = 0.9958), compared to 0.031 %/mm (R (2) = 0.9960) in the new cushion. Although the dose attenuation rate of the new cushion was three times that of the normal cushion, the high agreement between calculated dose by RTPS and ionization chamber measurements was within approximately 0.005 %/mm. Thus, the results of the current study indicate that the new cushion may be effective in clinical use for dose calculation accuracy in RTPS. PMID:27260347

  10. 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

  11. 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.

  12. Virtual flight simulation of a dual rotor micro air vehicle

    NASA Astrophysics Data System (ADS)

    Cai, Hongming

    2015-02-01

    In this paper, a new computational method is developed based on computational fluid dynamics (CFD) coupled with rigid body dynamics (RBD) and flight control law in an in-house programmed source code. The CFD solver is established based on momentum source method, preconditioning method, lower-upper symmetric Gauss-Seidel iteration method, and moving overset grid method. Two-equation shear-stress transport k - ω turbulence model is employed to close the governing equations. Third-order Adams prediction-correction method is used to couple CFD and RBD in the inner iteration. The wing-rock motion of the delta wing is simulated to validate the capability of the computational method for virtual flight simulation. Finally, the developed computational method is employed to simulate the longitudinal virtual flight of a dual rotor micro air vehicle (MAV). Results show that the computational method can simulate the virtual flight of the dual rotor MAV.

  13. 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

  14. Air pollution and health risks due to vehicle traffic.

    PubMed

    Zhang, Kai; Batterman, Stuart

    2013-04-15

    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 speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response 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 NO2-NOx 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

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

    SciTech Connect

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

    1980-02-29

    Three electric propulsion systems using an aluminum-air battery were analyzed and compared to the internal-combustion-engine (ICE) vehicle. The analysis used projected battery characteristics extrapolated from laboratory measurements which were obtained in late 1979 and early 1980. In the analysis, 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. Projected Al-air battery power density, energy density, mass, and volume characteristics were based on recent experimental results of the Al-air battery development program at Lawrence Livermore Laboratory. All three electric systems compared favorably with the ICE vehicle.

  16. 78 FR 9623 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... National Highway Traffic Safety Administration 49 CFR Part 571 RIN 2127-AL11 Federal Motor Vehicle Safety... published a final rule that amended the Federal motor vehicle safety standard for air brake systems by... published a final rule in the Federal Register amending Federal Motor Vehicle Safety Standard (FMVSS)...

  17. 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.

  18. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 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 HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Foam-filled cushions for sliding trays

    NASA Technical Reports Server (NTRS)

    Nahin, S. B.; Robb, P. H.

    1980-01-01

    Polytetrafluoroethylene tube filled with polyurethane foam forms low friction sliding surface that cushions vibrations and absorbs manufacturing tolerances and misalignment. Possible uses include packaging of components for shipping and seals for doors in lockers, cars, and refrigerators.

  4. 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.

  5. 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

  6. 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.

  7. Dynamics, stability, and control analyses of flapping wing micro-air vehicles

    NASA Astrophysics Data System (ADS)

    Orlowski, Christopher T.; Girard, Anouck R.

    2012-05-01

    The paper presents an overview of the various analyses of flight dynamics, stability, and control of flapping wing micro-air vehicles available in the literature. The potential benefits of flapping wing micro-air vehicles for civil, military, and search and rescue operations are numerous. The majority of the flight dynamics research involves the standard aircraft (6DOF) equations of motion, although a growth is evident in examining the multibody flight dynamics models of flapping wing micro-air vehicles. The stability of flapping wing micro-air vehicles is largely studied in the vicinity of hover and forward flight. The majority of stability studies focus on linear, time-invariant stability in the vicinity of reference flight conditions, such as hover or forward flight. The consistent result is that flapping wing micro-air vehicles are unstable in an open loop setting. The unstable result is based on linear and nonlinear stability analyses. Control has been demonstrated for hovering and forward flight through various methods, both linear and nonlinear in nature. The entirety of reported research into the stability and control of flapping wing micro-air vehicles has neglected the mass effects of the wings on the position and orientation of the central body. Successful control of a flapping wing micro-air vehicle, with the wings' mass effects included, is still an open research area.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Target location by self-organizing autonomous air vehicles

    NASA Astrophysics Data System (ADS)

    Brown, Kim; Bowyer, Richard S.; Koks, Don

    2002-08-01

    Target location is a problem where the application of multiple sensors that are geographically distributed can determine or improve the location estimate of a target. If these sensors are capable of cooperative behaviour then the information from each sensor can be autonomously fused to provide an estimate of the target position. The individual sensors may be quite unsophisticated, yet the observation system that is created through cooperation and adaptive networking of these sensors provides sufficient process gain to achieve target location accuracies similar to those of expensive centralized sensor systems. The accuracy of target location estimates depends heavily on the separation distance between the sensors. Large baseline geometry takes advantage of many seemingly unsophisticated bearing measurements that are organised into a coordinated observation system to locate a target. Team formation is one method to address coordination of distributed sensors, data fusion, sensor resource and energy management, and communication link control based on the concept of cooperating machines1,2,3. We apply an algorithm for agent team formation4 inspired by the self-organising behaviour observed in colonies of ants, to the problem of integrating the sensors of a group of networked mini-Autonomous Air Vehicles (AAVs). The mini-AAVs are tasked to locate targets within a region of interest. The challenge we address is to make the location estimation system adaptive to a dynamic environment and robust to failure. Simulation results are presented which address issues in distributed data fusion, sensor resource and energy management, and communication link control, for a group of mini-AAVs.

  13. 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

  14. 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

  15. 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

  16. 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

  17. 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, Techinical Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  18. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray ...

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

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

  19. 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, Supply Warehouse, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  20. 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

  1. 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

  2. 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/L’GARDE team’s long-lived, maneuverable platform to explore the Venus upper atmosphere. It focuses on the air vehicle design and entry CONOPs and their interdependencies.

  3. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES General Compliance Provisions for Control of Air Pollution From New and In-Use Light...-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a test group, will...

  4. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  5. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  6. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conditioning for test vehicles. 86.1832-01 Section 86.1832-01 Protection of Environment ENVIRONMENTAL... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... and 86.1828-01: (a)(1) Where it is expected that more than 33 percent of a car line, within a...

  7. 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…

  8. [Impact of heavy-duty diesel vehicles on air quality and control of their emissions].

    PubMed

    Zhou, Lei; Wang, Bo-Guang; Tang, Da-Gang

    2011-08-01

    Through an analysis of the characteristics of diesel vehicle emissions and motor vehicle emissions inventories, this paper examines the impact of heavy-duty diesel vehicles on air quality in China as well as issues related to the control of their emissions. Heavy-duty diesel vehicles emit large amounts of nitrogen oxides and particulate matter. Nitrogen oxides is one of the important precursors for the formation of secondary particles and ozone in the atmosphere, causing regional haze. Diesel particulate matter is a major toxic air pollutant with adverse effect on human health, and in particular, the ultrafine particles in 30-100 nm size range can pose great health risks because of its extremely small sizes. Motor vehicles have become a major source of air pollution in many metropolitan areas and city cluster in China, and among them the heavy-duty diesel vehicles are a dominant contributor of nitrogen oxides and particulate matter emissions. Hence, controlling heavy-duty diesel vehicle emissions should be a key component of an effective air quality management plan, and a number of issues related to heavy-duty diesel vehicle emissions need to be addressed.

  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. 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.

  11. Environmental impacts associated with the aluminum-air battery electric vehicle fuel cycle

    SciTech Connect

    Berger, K.J.E.

    1982-01-01

    The aluminum-air battery concept is discussed, and a scenario is developed which forecasts ten million aluminum-air electric vehicles in the US by the year 2000. An estimation is made regarding the consumption of natural resources and generation of wastes due to the aluminum-air battery's fuel cycle and to the increased demand on the US aluminum industry because of the scenario. The battery's fuel cycle considers the entire process of its generation and use; this includes the extraction of the raw material, processing, transportation, distribution, implementation and recycling. An analysis is also performed in which a comparison is made between the air emissions from an aluminum-air battery electric vehicle and those generated by a standard internal combustion engine vehicle. Finally, an examination is made of various ways by which potential adverse environmental impacts may be eliminated or reduced. The document concludes that no serious environmental impacts should be expected from the aluminum-air battery electric vehicle fuel cycle (provided a clean and inexpensive source of electricity is available) and that the introduction of such a vehicle could aid in reducing urban air pollution.

  12. 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.

  13. 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...

  14. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false OTC denture cushion or pad. 872.3540 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a prefabricated or noncustom made disposable device that...

  15. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false OTC denture cushion or pad. 872.3540 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a prefabricated or noncustom made disposable device that...

  16. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false OTC denture cushion or pad. 872.3540 Section 872...) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad. (a) Identification. An OTC denture cushion or pad is a prefabricated or noncustom made disposable device that...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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 engine... mammals must only be placed in animal cargo spaces that have a supply of air sufficient for each...

  18. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 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 animals... the animal cargo space in a manner that provides protection from the elements and that allows...

  19. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 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 animals... the animal cargo space in a manner that provides protection from the elements and that allows...

  20. 9 CFR 3.15 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to transport dogs and cats must be designed, constructed, and maintained in a manner that at all times protects... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  1. 9 CFR 3.37 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... the safety and comfort of the live guinea pigs and hamsters at all times. (b) The animal cargo space... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... be placed in an animal cargo space that does not have a supply of air sufficient for normal...

  2. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... comfort of the live animals contained therein at all times. (b) The animal cargo space shall be... (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...

  3. 9 CFR 3.37 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... the safety and comfort of the live guinea pigs and hamsters at all times. (b) The animal cargo space... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... be placed in an animal cargo space that does not have a supply of air sufficient for normal...

  4. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... conveyances (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used to transport nonhuman primates must be designed, constructed, and maintained in a manner that at all times... cargo space must have a supply of air that is sufficient for the normal breathing of all the...

  5. 9 CFR 3.88 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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 animals... the animal cargo space in a manner that provides protection from the elements and that allows...

  6. 9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 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 engine... mammals must only be placed in animal cargo spaces that have a supply of air sufficient for each...

  7. 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... cargo space must have a supply of air that is sufficient for the normal breathing of all the animals... the animal cargo space in a manner that provides protection from the elements and that allows...

  8. Modified fire-resistant foams forseat cushions

    NASA Technical Reports Server (NTRS)

    Gagliani, J.; Lee, R.; Sorathia, U. A. K.; Wilcoxson, A. L.

    1981-01-01

    Modified polyimide-polymer resins are precursors for new family of resilient fire-resistant foams. Terpolyimide foams containing long-chain aliphatic diamines withstand 50,000 cycles of compression over a 200 pound load - an equivalent of 3 years of continuous use as seat cushion filler.

  9. A preliminary study of the air data sensing problem on a re-entry vehicle

    NASA Astrophysics Data System (ADS)

    Hettena, E.

    1995-03-01

    A brief review of different measurement techniques for speed, pressure, and temperature on a re-entry vehicle is given in order to evaluate their applicability and limitations to the design of an air data system. A pressure-sensors based air data system is then assumed and an engineering aerodynamic model is used to investigate the influence of the measurement errors on the relevant air data parameters necessary for light guidance and control.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA

    NASA Astrophysics Data System (ADS)

    Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

    2008-04-01

    The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

  20. Multi-Disciplinary Design Optimization of Hypersonic Air-Breathing Vehicle

    NASA Astrophysics Data System (ADS)

    Wu, Peng; Tang, Zhili; Sheng, Jianda

    2016-06-01

    A 2D hypersonic vehicle shape with an idealized scramjet is designed at a cruise regime: Mach number (Ma) = 8.0, Angle of attack (AOA) = 0 deg and altitude (H) = 30kms. Then a multi-objective design optimization of the 2D vehicle is carried out by using a Pareto Non-dominated Sorting Genetic Algorithm II (NSGA-II). In the optimization process, the flow around the air-breathing vehicle is simulated by inviscid Euler equations using FLUENT software and the combustion in the combustor is modeled by a methodology based on the well known combination effects of area-varying pipe flow and heat transfer pipe flow. Optimization results reveal tradeoffs among total pressure recovery coefficient of forebody, lift to drag ratio of vehicle, specific impulse of scramjet engine and the maximum temperature on the surface of vehicle.

  1. 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.

  2. Indoor-outdoor air quality relationships in vehicle: effect of driving environment and ventilation modes

    NASA Astrophysics Data System (ADS)

    Chan, Andy T.; Chung, Michael W.

    Nitrogen oxides and carbon monoxide concentration were measured inside and outside of a light-goods-vehicle at different locations and driving conditions for a 6-month period. To investigate the exposure of the vehicle passenger to the specified outdoor pollutant, the indoor-outdoor air quality (IO) relationships under various driving conditions, namely traffic density, ventilation modes and type of roadway were studied. Four main types of driving environments were selected: highway, countryside, urban street and tunnel. The vehicle was driven under the three main types of ventilation conditions: air-conditioning with air-recirculation, air-conditioning with fresh air intake and natural ventilation. It is found that the IO ratio is not specific only to the mode of ventilation but also depends on the driving environment. The IO value can vary drastically even using the same ventilation mode when the vehicle is travelling in a different environment. It is found that using fresh-air ventilation mode, the IO can change from approximately 0.5-3 as it commutes from a highway to the countryside. The results also indicate that indoor NO level increased as the traffic density increases. The fluctuation of indoor NO level of naturally ventilated vehicle followed the variation of outdoor NO concentration with the IO value varying from 0.5 to 5. The results also show that even in an air-conditioned van, the indoor NO and CO concentration is significantly affected by that outdoor. It suggests the use of different ventilation mode when commuting in different environment.

  3. 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.

  4. Measurement of Load Redistribution Properties of Wheelchair Cushions Using a Compliant Cushion Loading Indenter.

    PubMed

    Kumar, Nagmesh; Sprigle, Stephen; Martin, James S

    2015-01-01

    The aim of this project was to develop and validate a compliant cushion loading indenter (CCLI) capable of evaluating wheelchair cushion performance by measuring internal pressures and deflection. The design of the CCLI consists of 3 subsystems: 1) an internal substructure with medial and lateral protuberances to mimic the load-bearing ischial tuberosities and trochanters, 2) an elastomeric shell to mimic soft tissue and 3) instrumentation to measure internal pressures at both protuberances and deflection of the elastomer at 7 locations. It is parametrically designed so can be scaled larger or smaller to represent different body sizes. To assess the repeatability and sensitivity of measurements, the model was loaded onto two wheelchair cushions, 3″ flat foam and Jay3, using two loads, 44kgf and 53kgf, representing the average upper body mass of 70kg and 83kg persons, respectively. The results showed a high precision of pressure and deflection measurement across two different cushions and loads. Under both loads, pressure measurements exhibited a standard error of < 1 mm and <3 mmHg. The standard deviations of deflection values were less than 2.5 mm (0.1 in.). The pressures and absolute deflection differed significantly across load and cushion type indicating sensitivity to change. PMID:26427740

  5. 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.

  6. 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 55°C, 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

  7. 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.

  8. Vehicle height and posture control of the electronic air suspension system using the hybrid system approach

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    The electronic air suspension (EAS) system can improve ride comfort, fuel economy and handling safety of vehicles by adjusting vehicle height. This paper describes the development of a novel controller using the hybrid system approach to adjust the vehicle height (height control) and to regulate the roll and pitch angles of the vehicle body during the height adjustment process (posture control). The vehicle height adjustment system of EAS poses challenging hybrid control problems, since it features different discrete modes of operation, where each mode has an associated linear continuous-time dynamic. In this paper, we propose a novel approach to the modelling and controller design problem for the vehicle height adjustment system of EAS. The system model is described firstly in the hybrid system description language (HYSDEL) to obtain a mixed logical dynamical (MLD) hybrid model. For the resulting model, a hybrid model predictive controller is tuned to improve the vehicle height and posture tracking accuracy and to achieve the on-off statuses direct control of solenoid valves. The effectiveness and performance of the proposed approach are demonstrated by simulations and actual vehicle tests.

  9. 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.

  10. Use of cooperative unmanned air and ground vehicles for detection and disposal of mines

    NASA Astrophysics Data System (ADS)

    Zawodny MacArthur, Erica; MacArthur, Donald; Crane, Carl

    2005-11-01

    The objective of this research is to extend the sensing capabilities of a multi-vehicle ground system by incorporating the environmental perception abilities of unmanned aerial vehicles. The aerial vehicle used in this research is a Miniature Aircraft Gas Xcell RC helicopter. It is outfitted with a sensor payload containing stereo vision cameras, GPS, and a digital compass. Geo- referenced images are gathered using the above sensors that are used in this research to create a map of the operating region. The ground vehicle used in this research is an automated Suzuki Mini-Quad ATV. It has the following onboard sensors: single-vision camera, laser range device, digital compass, GPS, and an encoder. The ground vehicle uses the above sensors and the map provided by the helicopter to traverse the region, locate, and isolate simulated land mines. The base station consists of a laptop that provides a communication link between the aerial and ground vehicle systems. It also provides the operator with system operation information and statistics. All communication between the vehicles and the base station is performed using JAUS (Joint Architecture for Unmanned Systems) messages. The JAUS architecture is employed as a means to organize inter-vehicle and intra-vehicle communication and system component hierarchy. The purpose of JAUS is to provide interoperability between various unmanned systems and subsystems for both military and commercial applications. JAUS seeks to achieve this through the development of functionally cohesive building blocks called components whose interface messages are clearly defined. The JAUS architecture allows for a layered control strategy which has specific message sets for each layer of control. Implementation of the JAUS architecture allows for ease of software development for a multi- vehicle system. This experiment demonstrates how an air-ground vehicle system can be used to cooperatively locate and dispose of simulated mines.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... comfort of the rabbits contained therein at all times. (b) The animal cargo space shall be constructed and... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... during transportation in commerce. (c) No live rabbit shall be placed in an animal cargo space that...

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

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... conveyances (motor vehicle, rail, air and marine). (a) The animal cargo space of primary conveyances used in... safety and comfort of the marine mammals contained within at all times. All primary conveyances used must... animal cargo space must be constructed and maintained in a manner that will prevent the ingress of...

  17. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... comfort of the rabbits contained therein at all times. (b) The animal cargo space shall be constructed and... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... during transportation in commerce. (c) No live rabbit shall be placed in an animal cargo space that...

  18. 75 FR 51521 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Technical Report on the Effectiveness...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... National Highway Traffic Safety Administration Federal Motor Vehicle Safety Standards; Air Brake Systems... AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation. ACTION... charge by sending a self-addressed mailing label to Charles J. Kahane (NVS-431), National Highway...

  19. 76 FR 17487 - Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air Conditioning Sector...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ... expanding the list of acceptable substitutes for use in the motor vehicle air conditioning end-use as a...-duty trucks. The substitute is a non-ozone-depleting gas and consequently does not contribute to... Order FMEA--Failure Mode and Effect Analysis FR--Federal Register GWP--Global Warming Potential...

  20. 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.

  1. 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...

  2. Ancillary benefits for climate change mitigation and air pollution control in the world's motor vehicle fleets.

    PubMed

    Walsh, Michael P

    2008-01-01

    The global motor vehicle population has grown very rapidly in the past half century and is expected to continue to grow rapidly for the next several decades, especially in developing countries. As a result, vehicles are a major source of urban air pollution in many cities and are the fastest-growing source of greenhouse emissions. Strategies exist to reduce both problems, but many countries emphasize one over the other rather than pursuing strategies that reduce both concerns. Using diesel as an example, this article illustrates that it is now possible not only to reduce carbon dioxide with the increased use of diesel vehicles but also to improve urban air pollution. Doing so requires both stringent emissions regulations and clean fuels. Several principles contained in the Bellagio Memorandum are highlighted as guides for policy makers.

  3. 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.

  4. Structural characteristics via SLDV for a class of morphing micro-air-vehicles

    NASA Astrophysics Data System (ADS)

    Diggs, Edward C.; Bilgen, Onur; Kurdila, Andrew; Kochersburger, Kevin; Inman, Dan; Vignola, Joe

    2007-04-01

    Conventional control surfaces have been used in most carbon fiber composite, membrane-wing autonomous micro air vehicles (MAV). In some cases, vehicle morphing is achieved using servo actuators to articulate vehicle kinematic joints, or to deform crucial wing / tail surfaces. However, articulated lifting surfaces and articulated wing sections are difficult to instrument and fabricate in a repeatable fashion. Assembly is complex and time consuming. The goal of this paper is to establish the feasibility of morphing wings on autonomous MAVs that are actuated via active materials. Active actuation is achieved via a type of piezoceramic composite called Macro Fiber Composite (MFC). This paper investigates the structural dynamics of morphing wings on MAVs that are actuated via active composites. This paper continues the work presented in1 by considering structural dynamic characteristics of the morphing vehicle determined through Scanning Laser Doppler Vibrometry (SLDV).

  5. 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.

  6. 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

  7. Zinc/air fuel cell for electric vehicles

    SciTech Connect

    Cherepy, N. J.; Krueger, R.; Cooper, J. F.

    1999-01-01

    We are conducting tests of an advanced zinc/air fuel cell design to determine effectiveness in various commercial applications. Our 322-cm2 cell uses gravity-fed zinc pellets as the anode, 12 M KOH electrolyte, and an air cathode catalyzed by a cobalt-porphyrin complex on carbon black. A single 322 cm2 cell runs at a standard operating power of 38 W (1200 W/m2) at 39 A (1245 A/m2) and 0.96 V with a power density of 2400 W/m2 at 0.67 V. With improved current collection hardware, already demonstrated in the laboratory, power generation increases to -3600 W/m2 at 1V. We conducted a 50-hour test in which a cell generated 587 Ah and 569 Wh. The power that may be generated increases by a factor of 2.5 between T = 28 °C and 52 °C. Electrolyte capacity, without stabilization additives, was measured at 147 Ah/L

  8. Design analysis of an aluminum-air battery for vehicle operations. Transportation systems research

    SciTech Connect

    Behrin, E.; Wood, R.L.; Salisbury, J.D.; Whisler, D.J.; Hudson, C.L.

    1983-03-18

    The objective of the study reported was to perform a detailed configuration analysis of an aluminum-air battery, evaluate various automobile propulsion systems utilizing the Al-air battery, and estimate the performance and cost of vehicles incorporating these propulsion systems. A preliminary engineering design is performed. A physical model and a cell-performance model of a conceptual mass-produced Al-air battery were constructed and work together to characterize the battery system. The physical battery model is based on a specific battery design concept and defines the mass and volume of a complete Al-air battery system. The cell-performance model simulates the electrical and electrochemical characteristics of the battery. The physical model and two versions of the cell-performance model - near-term and optimistic - were used in a vehicle-conversion analysis to evaluate three automotive propulsion systems - Al-air battery only, Al-air battery/secondary battery, and Al-air battery/flywheel. (LEW)

  9. 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

  10. Effect of vehicle type on the performance of second generation air bags for child occupants.

    PubMed

    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

  11. Concentrations of air toxics in motor vehicle-dominated environments.

    PubMed

    Fujita, Eric M; Campbell, David E; Zielinska, Barbara; Arnott, William P; Chow, Judith C

    2011-02-01

    We at the Desert Research Institute (DRI*) measured volatile organic compounds (VOCs), including several mobile-source air toxics (MSATs), particulate matter with a mass mean aerodynamic diameter < or = 2.5 pm (PM2.5), black carbon (BC), nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO) on highways in Los Angeles County during summer and fall 2004, to characterize the diurnal and seasonal variations in measured concentrations related to volume and mix of traffic. Concentrations of on-road pollutants were then compared to corresponding measurements at fixed monitoring sites. The on-road concentrations of CO and MSATs were higher in the morning under stable atmospheric conditions and during periods of higher traffic volumes. In contrast, BC concentrations, measured as particulate light absorption, were higher on truck routes during the midday sampling periods despite more unstable atmospheric conditions. Compared to the measurements at the three near-road sites, the 1-hour averages of on-road BC concentrations were as much as an order of magnitude higher. The peak 1-minute average concentrations were two orders of magnitude higher for BC and were between two and six times higher for PM2.5 mass. The on-road concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) during the summer were 3.5 +/- 0.7 and 1.2 +/- 0.6 times higher during morning and afternoon commuting periods, respectively, compared to annual average 24-hour concentrations measured at air toxic monitoring network sites. These ratios were higher during the fall, with smaller diurnal differences (4.8 +/- 0.7 and 3.9 +/- 0.6 for morning and afternoon commuting periods, respectively). Ratios similar to those for BTEX were obtained for 1,3-butadiene (BD) and styrene. On-road concentrations of formaldehyde and acetaldehyde were up to two times higher than at air toxics monitoring sites, with fall ratios slightly higher than summer ratios. Chemical mass balance (CMB) receptor

  12. 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.

  13. Modulation of vesicle adhesion and spreading kinetics by hyaluronan cushions.

    PubMed

    Limozin, Laurent; Sengupta, Kheya

    2007-11-01

    The adhesion of giant unilamellar phospholipid vesicles to planar substrates coated with extracellular matrix mimetic cushions of hyaluronan is studied using quantitative reflection interference contrast microscopy. The absolute height of the vesicle membrane at the vicinity of the substrate is measured by considering, for the first time, the refractive indices of the reflecting media. The thickness of the cushion is varied in the range of approximately 50-100 nm, by designing various coupling strategies. On bare protein-coated substrates, the vesicles spread fast (0.5 s) and form a uniform adhesion disk, with the average membrane height approximately 4 nm. On thick hyaluronan cushions (>80 nm), the membrane height is approximately the same as the thickness of the cushion, implying that the vesicle lies on top of the cushion. On a thin and inhomogeneous hyaluronan cushion, the adhesion is modified but not prevented. The spreading is slow ( approximately 20 s) compared to the no-cushion case. The average membrane height is approximately 10 nm and the adhesion disk is studded with blisterlike structures. Observations with fluorescent hyaluronan indicate that the polymer is compressed under, rather than expelled from, the adhesion disk. The adhesion energy density is approximately threefold higher in the no-cushion case (1.2 microJ/m(2)) as compared to the thin-cushion case (0.54 microJ/m(2)). In the thin-cushion case, the presence of short ( approximately 4 nm) glyco-polymers on the vesicles results in a hitherto unreported stable partial adhesion state--the membrane height ranges from zero to approximately 250 nm. The minimal model system presented here mimics in vitro the hyaluronan-modulated early stages of cell adhesion, and demonstrates that the presence of a polymer cushion influences both the final equilibrium adhesion-state and the spreading kinetics. PMID:17631530

  14. A regional review of air medical transports for fatal motor vehicle crashes.

    PubMed

    Garthe, E A; Mango, N K; Prenney, B

    2000-01-01

    This article presents study results from an assessment of the performance of the air medical (and advanced life support) components of the EMS system in response to fatal motor vehicle crashes. Results are presented for one of Massachusetts' five EMS regions, including the finding that air medical transports are involved in 20% of the fatal crashes for the region and transport 11% of the involved individuals. Although the study focused on air medical utilization, it also identified issues related to the future implementation of motor vehicle automatic crash notification (ACN) and telematics that could relay crash severity data from onboard computers (e.g., event data recorders) to auto manufacturers' help centers or state emergency call centers. This technology will place new demands on state EMS systems. To meet the challenges posed by these technological changes, states will need to assess the type and number of EMS services required to respond to ACN motor vehicle crashes and develop methods to determine what level of service to deploy based on the information relayed from the vehicles. An initial step in this evaluation process is to determine the current use of EMS resources to place planned system changes and demand into context.

  15. 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.

  16. 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).

  17. 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.

  18. 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

  19. 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).

  20. Concentrations of vehicle-related air pollutants in an urban parking garage.

    PubMed

    Kim, Sung R; Dominici, Francesca; Buckley, Timothy J

    2007-11-01

    There is growing evidence that traffic-related air pollution poses a public health threat, yet the dynamics of human exposure are not well understood. The urban parking garage is a microenvironment that is of concern but has not been characterized. Using time-resolved measurement methods, we evaluated air toxics levels within an urban parking garage and assessed the influence of vehicle activity and type on their levels. Carbon monoxide (CO) and particle-bound polycyclic aromatic hydrocarbons (pPAH) were measured with direct-reading instruments. Volatile organic compounds (VOCs) were measured in 30 min intervals using a sorbent tube loaded sequential sampler. Vehicle volume and type were evaluated by video recording. Sampling was conducted from June 24 to July 17, 2002. We observed garage traffic median volumes of 71 counts/h on weekdays and 6 counts/h on weekends. The 12-fold reduction in traffic volume from weekday to weekend corresponded with a decrease in median air pollution that varied from a minimum 2- (CO) to a maximum 7 (pPAH)-fold. The actual 30-min median weekday and weekend values were: CO--2.6/1.2 ppm; pPAH--19/2.6 ng/m(3); 1,3-butadiene-0.5/0.2 microg/m(3), MTBE-7.4/0.4 microg/m(3); and benzene-2.7/0.3 microg/m(3). The influence of traffic was quantified using longitudinal models. The pollutant coefficients provide an indication of the average air pollution vehicle source contribution and ranged from 0.31 (CO) to 1.08 (pPAH) percent increase/vehicle count. For some pollutants, a slightly higher (0.5-0.6%) coefficient was observed for light-trucks relative to cars. This study has public health relevance in providing a unique assessment of air pollution levels and source contribution for the urban parking garage.

  1. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false OTC denture cushion or pad. 872.3540 Section 872.3540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad....

  2. 21 CFR 872.3540 - OTC denture cushion or pad.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false OTC denture cushion or pad. 872.3540 Section 872.3540 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3540 OTC denture cushion or pad....

  3. 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 audiometric testing. (a) Identification. An earphone cushion for audiometric testing is a device that is used... controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of...

  4. 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 audiometric testing. (a) Identification. An earphone cushion for audiometric testing is a device that is used... controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Estimates of the cost and energy consumption of aluminum-air electric vehicles

    SciTech Connect

    Cooper, J.F.

    1980-11-01

    Economic costs and primary energy consumption are estimated for general purpose electric vehicles using aluminum-air propulsion batteries within the time frame of the 1990's (earliest possible date of introduction). Critical assumptions are given. The results show that, for a 40 kW, 70 kWh battery used in a vehicle traveling 16,000 km/y, the total capital investment in electricity and aluminum production plants and fuels distribution system was $2250 or $32/kWh. Of this, the aluminum plants contributed 60%, and the fuels distribution system, 3% (less than $1/kWh). The introduction of 1,000,000 vehicles per year in 1995 would increase domestic aluminum demand by below 5% per year, and electricity demand by less than 0.2% per year.

  12. 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.

  13. 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.

  14. 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.

  15. Weight and volume estimates for aluminum-air batteries designed for electric vehicle applications

    SciTech Connect

    Cooper, J.F.

    1980-01-01

    The weights and volumes of reactants, electrolyte, and hardware components are estimated for an aluminum-air battery designed for a 40-kW (peak), 70-kWh aluminum-air battery. Generalized equations are derived which express battery power and energy content as functions of total anode area, aluminum-anode weight, and discharge current density. Equations are also presented which express total battery weight and volume as linear combinations of the variables, anode area and anode weight. The sizing and placement of battery components within the engine compartment of typical five-passenger vehicles is briefly discussed.

  16. 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.

  17. 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

  18. Estimates of the cost and energy consumption of aluminum-air electric vehicles

    SciTech Connect

    Cooper, J.F.

    1980-11-01

    Economic costs and primary energy consumption are estimated for general purpose electric vehicles using aluminium-air propulsion batteries within the time frame of the 1990's (earliest possible date of introduction). Critical assumptions were: aluminum production at efficiencies at least as high as those of the best currently operating industrial installations; competitive performance automobiles with gasoline or diesel fuel economies at least as high as those of the best currently-available vehicles-13.5 to 19.3 tonne-km/liter (35 to 50 gross ton-miles/gal-fuel); and aluminum-air battery discharge efficiencies at least as high as those obtained with electrodes available prior to the start of the present alloy development program. For an aluminum-air fuel economy of 36 tonne/km/kg-Al (optimized low-gallium alloys), a total refueling cost of 5.6 cents/km (1979$) was estimated for a 1.27 tonne vehicle. This is equivalent to $2 to 3/gal for automobiles of the same weight with fuel economies of 13.5 to 19.3 tonne-km/liter. Critical to the cost estimate is the assumption of anode slab production directly from the product of a reduction cell by low cost casting and shearing operations. The total primary energy consumption was estimated to be 1.3 to 1.7 kWh/km (coal) for the electric vehicle, which corresponds roughly to the energy cost of the automobiles using liquid fuels synthesized from coal. The energy consumption is 30 to 70% greater than the reference automobile using petroleum-derived gasoline. The cost of the battery (including air-electrodes) was estimated to be about $30/kW including 30% markup over producer's cost; or $36/kW, if electrodes are used with 0.25 mg/cm/sup 2/ Pt loadings. (LCL)

  19. 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.

  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. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Development of the aluminum-air battery for electric vehicle applications

    SciTech Connect

    Cooper, J.F.; Homsy, R.V.

    1981-08-12

    Current progress is reported concerning the development of hardware for the aluminum-air electric vehicle battery. The polarization curves of large-scale aluminum-air cells (0.1-m/sup 2/ anodes) have been replicated in rapidly-refuelable cells of subscale size (167-cm/sup 2/) which were constructed for stacking into multicell modules. Solution-side current colllection by a structure which makes point- or line contacts at the aluminum/electrolyte interface is described. The technique allows rapid anode addition, minimizes anode fabrication costs, and simplifies cell design. The possible application of solution-side current collection to wedge-shaped cells allowing continuous anode feed and full utilization is discussed. Life-cycle testing of air electrodes in candidate battery electrolytes is reported. Temperature and aluminate concentration transients are modeled using experimental rate data. Program structure, technical strategy, goals, and economic analysis are briefly discussed.

  11. 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.

  12. 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.

  13. Indoor air as a vehicle for human pathogens: Introduction, objectives, and expectation of outcome.

    PubMed

    Sattar, Syed A

    2016-09-01

    Airborne spread of pathogens can be rapid, widespread, and difficult to prevent. In this international workshop, a panel of 6 experts will expound on the following: (1) the potential for indoor air to spread a wide range of human pathogens, plus engineering controls to reduce the risk for exposure to airborne infectious agents; (2) the behavior of aerosolized infectious agents indoors and the use of emerging air decontamination technologies; (3) a survey of quantitative methods to recover infectious agents and their surrogates from indoor air with regard to survival and inactivation of airborne pathogens; (4) mathematical models to predict the movement of pathogens indoors and the use of such information to optimize the benefits of air decontamination technologies; and (5) synergy between different infectious agents, such as legionellae and fungi, in the built environment predisposing to possible transmission-related health impacts of aerosolized biofilm-based opportunistic pathogens. After the presentations, the panel will address a set of preformulated questions on selection criteria for surrogate microbes to study the survival and inactivation of airborne human pathogens, desirable features of technologies for microbial decontamination of indoor air, knowledge gaps, and research needs. It is anticipated that the deliberations of the workshop will provide the attendees with an update on the significance of indoor air as a vehicle for transmitting human pathogens with a brief on what is currently being done to mitigate the risks from airborne infectious agents. PMID:27590701

  14. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives.

    PubMed

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research.

  15. Health effects associated with passenger vehicles: monetary values of air pollution.

    PubMed

    Marzouk, Mohamed; Madany, Magdy

    2012-01-01

    Air pollution is regarded as one of the highest priorities in environmental protection in both developed and developing countries. High levels of air pollution have adverse effects on human health that might cause premature death. This study presents the monetary value estimates for the adverse human health effects resulted from ambient air pollution. It aids decision makers to set priorities in the public health relevance of pollution abatement. The main driver of policymaker is the need to reduce the avoidable cardiopulmonary morbidity and mortality from pollutant exposures. The monetary valuation involves 2 steps: (i) relate levels of pollutants to mortality and morbidity (concentration-response relationships) and (ii) apply unit economic values. Cost of air pollution associated with passenger vehicles running over a major traffic bridge (6th of October Elevated Highway) is presented as a case study to demonstrate the use of monetary value of air pollution. The study proves that the cost of air pollution is extremely high and should not be overlooked.

  16. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives.

    PubMed

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research. PMID:27420065

  17. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives

    PubMed Central

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D.; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research. PMID:27420065

  18. 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.

  19. 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.

  20. OCTAVE: a bioinspired visuo-motor control system for the guidance of micro-air-vehicles

    NASA Astrophysics Data System (ADS)

    Ruffier, Franck; Franceschini, Nicolas

    2003-04-01

    We have developed a visually based autopilot for Micro Air Vehicles (MAV), which we have called OCTAVE (Optical altitude Control sysTem for Autonomous VEhicles). First we built a miniature MAV and an indoor test-bed. The mini-helicopter is tethered to a whirling arm and rotates around a central pole equipped with ground-truth positioning sensors for experimental evaluation. The 100-gram rotorcraft lifts itself by means of a single rotor that can also be tilted forward (pitch) to give the craft a horizontal thrust component (propulsive force). The helicopter"s eye is automatically oriented downwards over an environment composed of contrasting features randomly arranged on the floor. Here we show the feasibility of a ground avoiding system based on a low complexity opto-electronic system. The latter relies on an Elementary Motion Detector (EMD) that estimates the optic flow in the downward direction. The EMD functional structure is directly inspired by that of the fly"s EMDs, the functional scheme of which has been elucidated at our Laboratory by performing electrophysiological recordings while applying optical microstimuli to the retina. The OCTAVE autopilot makes the aircraft capable of effective terrain following at various speeds: the MAV performs reproducible manoeuvers such as smooth cruise flight over a planar ground and hill climbing. The overall processing electronics is very light-weight, which makes it highly suitable for mounting on-board micro air vehicles with an avionic payload in the order of only a few grams.

  1. 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

  2. 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 (iν) 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%).

  3. Development of a method for manufacturing customized nasal mask cushion for CPAP therapy.

    PubMed

    Hsu, Ding-Yang; Cheng, Yih-Lin; Bien, Mauo-Ying; Lee, Hsin-Chien

    2015-12-01

    A continuous positive airway pressure (CPAP) device is considered one of the most effective treatments for obstructive sleep apnea (OSA). However, many patients receiving this treatment complain of mask discomfort and other issues. Therefore, this study aimed to develop a customized nasal mask cushion to reduce the discomfort associated with conventional masks. First, a 3D face scanner was used to obtain 3D facial data of participants. Second, a model of the face was created by reverse-engineering and then used for the computer-aided design (CAD) of the cushion. Finally, computer numerical control (CNC) was used to manufacture the mold, into which silicone was then injected slowly. A perceived comfort questionnaire was used to compare the customized and conventional cushions. 40 patients were randomly divided into two groups: 20 patients in the control group used a conventional cushion, and the remaining 20 patients used the customized cushion. The customized cushion was found to be superior to the conventional cushion. There are clear differences in the headgear force of the two cushion types (P = 0.001). The customized cushion applied less force to a patient’s face than a conventional cushion. Furthermore, there were obvious differences in the fit of the cushions (P = 0.001). Patients using the customized cushions experienced a better fit than those using the conventional cushions. This study has developed a new method for manufacturing customized cushions with better cushion fit through rapid tooling.

  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.

  5. 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...

  6. 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...

  7. 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...

  8. 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

    ... procedure, Air pollution control, Reporting and recordkeeping requirements, Stratospheric ozone layer. Dated... AGENCY 40 CFR Part 82 RIN 2060-AR20 Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule... substitute for ozone- depleting substances (ODSs) in the motor vehicle air conditioning end- use within...

  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. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Multi-sensor fusion techniques for state estimation of micro air vehicles

    NASA Astrophysics Data System (ADS)

    Donavanik, Daniel; Hardt-Stremayr, Alexander; Gremillion, Gregory; Weiss, Stephan; Nothwang, William

    2016-05-01

    Aggressive flight of micro air vehicles (MAVs) in unstructured, GPS-denied environments poses unique challenges for estimation of vehicle pose and velocity due to the noise, delay, and drift in individual sensor measurements. Maneuvering flight at speeds in excess of 5 m/s poses additional challenges even for active range sensors; in the case of LIDAR, an assembled scan of the vehicles environment will in most cases be obsolete by the time it is processed. Multi-sensor fusion techniques which combine inertial measurements with passive vision techniques and/or LIDAR have achieved breakthroughs in the ability to maintain accurate state estimates without the use of external positioning sensors. In this paper, we survey algorithmic approaches to exploiting sensors with a wide range of nonlinear dynamics using filter and bundle-adjustment based approaches for state estimation and optimal control. From this foundation, we propose a biologically-inspired framework for incorporating the human operator in the loop as a privileged sensor in a combined human/autonomy paradigm.

  17. 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.

  18. 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.

  19. 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.

  20. Impact of multisource VOC emission on in-vehicle air quality: test chamber simulation

    NASA Astrophysics Data System (ADS)

    Brodzik, K.; Faber, J.; Goƚda-Kopek, A.; Łomankiewicz, D.

    2016-09-01

    Air quality inside vehicle may be strongly influenced by the presence of volatile organic compounds (VOC). The sources of these compounds may be different. In case of new vehicles VOC mainly originate from off-gassing of interior materials, while in used cars exterior pollution, like exhaust gases, starts to dominate. The aim of this work was to check the influence of multiple VOC sources on concentration of volatile organic compounds emitted from car interior parts. For this purpose material emission tests were performed in 1 m3 emission testing chamber (WKE 1000, Weiss, Germany) at 65 °C, 5% RH and with air exchange. Three different car parts were studied: sun visor, headlining, and handbrake lever cover. It was stated that volatile organic compounds concentration inside test chamber during the test performed with three different parts inside was significantly lower than those being result of addition of the results obtained for parts tested separately. Presented results indicate interactions between different materials and their emissions as well as prove that some of materials acts like sorbents.

  1. Air quality impacts of climate mitigation: UK policy and passenger vehicle choice.

    PubMed

    Mazzi, Eric A; Dowlatabadi, Hadi

    2007-01-15

    In 2001-2002 the UK began taxing vehicles according to CO2 emission rates. Since then, there has been a significant increase in consumer choice of small cars and diesel engines. We estimate CO2 reductions and air quality impacts resulting from UK consumers switching from petrol to diesel cars from 2001 to 2020. Annual reductions of 0.4 megatons (Mt) of CO2 and 1 million barrels of oil are estimated from switching to diesels. However, diesels emit higher levels of particulate matter estimated to result in 90 deaths annually (range 20-300). We estimate 570, 460, and 0 additional deaths per Mt of CO2 abated, for Euro III, Euro IV, and post-Euro IV emission class vehicles, respectively. CO2 policies are suspected to have contributed substantially to diesel growth, but the magnitude of impact has yet to be quantified rigorously. To the extent that CO2 policies contribute to diesel growth, coordinating CO2 controls with tightening of emission standards would save lives. This research shows that climate policy, while reducing fuel use and CO2, does not always ensure ancillary health benefits. Lessons from the UK can help inform policies designed elsewhere which strive to balance near-term ambient air quality and health with long-term climate mitigation.

  2. 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.

  3. 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

  4. 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.

  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. Mach 6.5 air induction system design for the Beta II 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, are developed and evaluated for performance benefits. The design is optimized by maximizing installed propulsion/vehicle system performance, and 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 approximately 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.

  7. 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

  8. 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

  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. Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

    NASA Astrophysics Data System (ADS)

    Tahmasian, Sevak; Woolsey, Craig A.

    2016-09-01

    A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

  12. Improved Adaptive-Reinforcement Learning Control for morphing unmanned air vehicles.

    PubMed

    Valasek, John; Doebbler, James; Tandale, Monish D; Meade, Andrew J

    2008-08-01

    This paper presents an improved Adaptive-Reinforcement Learning Control methodology for the problem of unmanned air vehicle morphing control. The reinforcement learning morphing control function that learns the optimal shape change policy is integrated with an adaptive dynamic inversion control trajectory tracking function. An episodic unsupervised learning simulation using the Q-learning method is developed to replace an earlier and less accurate Actor-Critic algorithm. Sequential Function Approximation, a Galerkin-based scattered data approximation scheme, replaces a K-Nearest Neighbors (KNN) method and is used to generalize the learning from previously experienced quantized states and actions to the continuous state-action space, all of which may not have been experienced before. The improved method showed smaller errors and improved learning of the optimal shape compared to the KNN. PMID:18632393

  13. 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.

  14. Improved Adaptive-Reinforcement Learning Control for morphing unmanned air vehicles.

    PubMed

    Valasek, John; Doebbler, James; Tandale, Monish D; Meade, Andrew J

    2008-08-01

    This paper presents an improved Adaptive-Reinforcement Learning Control methodology for the problem of unmanned air vehicle morphing control. The reinforcement learning morphing control function that learns the optimal shape change policy is integrated with an adaptive dynamic inversion control trajectory tracking function. An episodic unsupervised learning simulation using the Q-learning method is developed to replace an earlier and less accurate Actor-Critic algorithm. Sequential Function Approximation, a Galerkin-based scattered data approximation scheme, replaces a K-Nearest Neighbors (KNN) method and is used to generalize the learning from previously experienced quantized states and actions to the continuous state-action space, all of which may not have been experienced before. The improved method showed smaller errors and improved learning of the optimal shape compared to the KNN.

  15. Experimental Study on the Wing Lift Characteristics of Biplane Micro Air Vehicle

    NASA Astrophysics Data System (ADS)

    Akiyama, Kohei; Tezuka, Asei; Sunada, Yasuto; Rinoie, Kenichi

    This paper investigates wing aerodynamic characteristics used for bi-plane micro-air vehicles. Surface pressure distributions of two-dimensional biplane airfoils (4% cambered-plate airfoil) were measured at a chord Reynolds number of 6.4 × 104. Lift characteristics of three-dimensional biplane rectangular wings (aspect ratio of 3) were also measured at the same Reynolds number. It was indicated that the behaviors of laminar separation bubble formed both on the upper and lower airfoils/wings affects their lift characteristics. Bi-plane wings with positive stagger, i.e. protruded upper wing indicated higher maximum lift coefficient. This is caused by different behaviors of laminar separation bubble formed on the wing.

  16. Monitoring of atmospheric aerosol emissions using a remotely piloted air vehicle (RPV)-Borne Sensor Suite

    SciTech Connect

    1996-05-01

    We have developed a small sensor system, the micro-atmospheric measurement system ({mu}-AMS), to monitor and track aerosol emissions. The system was developed to fly aboard a remotely piloted air vehicle, or other mobile platform, to provide real-time particle measurements in effluent plumes and to collect particles for chemical analysis. The {mu}-AMS instrument measures atmospheric parameters including particle mass concentration and size distribution, temperature, humidity, and airspeed, altitude and position (by GPS receiver) each second. The sensor data are stored onboard and are also down linked to a ground station in real time. The {mu}-AMS is battery powered, small (8 in. dia x 36 in.), and lightweight (15 pounds). Aerosol concentrations and size distributions from above ground explosive tests, airbone urban pollution, and traffic-produced particulates are presented.

  17. 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.

  18. Robust tracking control for an air-breathing hypersonic vehicle with input constraints

    NASA Astrophysics Data System (ADS)

    Gao, Gang; Wang, Jinzhi; Wang, Xianghua

    2014-12-01

    The focus of this paper is on the design and simulation of robust tracking control for an air-breathing hypersonic vehicle (AHV), which is affected by high nonlinearity, uncertain parameters and input constraints. The linearisation method is employed for the longitudinal AHV model about a specific trim condition, and then considering the additive uncertainties of three parameters, the linearised model is just in the form of affine parameter dependence. From this point, the linear parameter-varying method is applied to design the desired controller. The poles for the closed-loop system of the linearised model are placed into a desired vertical strip, and the quadratic stability of the closed-loop system is guaranteed. Input constraints of the AHV are addressed by additional linear matrix inequalities. Finally, the designed controller is evaluated on the nonlinear AHV model and simulation results demonstrate excellent tracking performance with good robustness.

  19. In-flight oxygen collection for a two-stage air-launch vehicle: integration of vehicle and separation cycle design

    NASA Astrophysics Data System (ADS)

    Verstraete, D.; Bizzarri, D.; Hendrick, P.

    2009-09-01

    In-flight oxygen collection is a very promising technique to reduce the launch costs and improve the payload capabilities of two-stage-to-orbit semireusable launchers. Using liquid hydrogen the incoming air is deeply cooled and enriched in oxygen during the cruise phase of the first stage. The liquified enriched air is stored in the second stage which is then launched into orbit. This paper gives the result of a conceptual design of a two-stage-to-orbit air launched space vehicle. The mass, aerodynamic, and propulsive characteristics of the first stage are determined and an assessment of the influence of the collection plant performance on the subsonic first stage is made. The results for a centrifugally enhanced destillation unit are given together with the plant cycle arrangement. Integration options for the plant into the first stage are proposed and a short description of the air separation test unit and its test bench is also given.

  20. 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.

  1. 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.

  2. A parallel expert system for the control of a robotic air vehicle

    NASA Technical Reports Server (NTRS)

    Shakley, Donald; Lamont, Gary B.

    1988-01-01

    Expert systems can be used to govern the intelligent control of vehicles, for example the Robotic Air Vehicle (RAV). Due to the nature of the RAV system the associated expert system needs to perform in a demanding real-time environment. The use of a parallel processing capability to support the associated expert system's computational requirement is critical in this application. Thus, algorithms for parallel real-time expert systems must be designed, analyzed, and synthesized. The design process incorporates a consideration of the rule-set/face-set size along with representation issues. These issues are looked at in reference to information movement and various inference mechanisms. Also examined is the process involved with transporting the RAV expert system functions from the TI Explorer, where they are implemented in the Automated Reasoning Tool (ART), to the iPSC Hypercube, where the system is synthesized using Concurrent Common LISP (CCLISP). The transformation process for the ART to CCLISP conversion is described. The performance characteristics of the parallel implementation of these expert systems on the iPSC Hypercube are compared to the TI Explorer implementation.

  3. 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.

  4. Stereo vision-based obstacle avoidance for micro air vehicles using an egocylindrical image space representation

    NASA Astrophysics Data System (ADS)

    Brockers, R.; Fragoso, A.; Matthies, L.

    2016-05-01

    Micro air vehicles which operate autonomously at low altitude in cluttered environments require a method for onboard obstacle avoidance for safe operation. Previous methods deploy either purely reactive approaches, mapping low-level visual features directly to actuator inputs to maneuver the vehicle around the obstacle, or deliberative methods that use on-board 3-D sensors to create a 3-D, voxel-based world model, which is then used to generate collision free 3-D trajectories. In this paper, we use forward-looking stereo vision with a large horizontal and vertical field of view and project range from stereo into a novel robot-centered, cylindrical, inverse range map we call an egocylinder. With this implementation we reduce the complexity of our world representation from a 3D map to a 2.5D image-space representation, which supports very efficient motion planning and collision checking, and allows to implement configuration space expansion as an image processing function directly on the egocylinder. Deploying a fast reactive motion planner directly on the configuration space expanded egocylinder image, we demonstrate the effectiveness of this new approach experimentally in an indoor environment.

  5. 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.

  6. 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 Liénard system perspective. At last, simulations demonstrate the great control performance and the uncertainty rejection ability of the robust scheme.

  7. 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.

  8. 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.

  9. 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.

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

    SciTech Connect

    Rudd, E.J. . Research and Development Center); 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--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.

  11. Aerodynamic experimentation with ducted models as applied to hypersonic air-breathing vehicles

    NASA Astrophysics Data System (ADS)

    Goon'ko, Yu. P.

    A methodology of experimentation in high supersonic wind tunnels for studying aerodynamic characteristics of hypersonic flying vehicles powered by air-breathing engines is discussed. Investigations of such total aerodynamic forces as drag, lift and pitching moment at testing the models are implicit when the air flow through the model ducts is accomplished so that to provide the simulation of the external flow around the airplane and flow over the inlets, but the operating engines and, hence, the exhaust jets are not modeled. The methods used for testing such models are based on the measurement of duct stream parameters alongside with the balance measurement of aerodynamic forces acting on the models. In the tests, aerometric tools are used such as narrow metering nozzles (plugs), pitot and static pressure probes, stagnation temperature probes and pressure orifices in walls of the model duct. The aerometric data serve to determine the flow rate and momentum of the stream at the duct exit. The internal non-simulated forces of the model ducts are also determined using the conservation equations for energy, mass flow and momentum, and these forces are eliminated from the aerodynamic test results. The techniques of the said model testing have been well developed as applied to supersonic aircraft, however their application for hypersonic vehicles whose models are tested at high supersonic speeds, Mach number M∞>4, implies some specific features. In the present paper, the results of experimental and theoretical study of these features are discussed. Some experimental data on aerodynamics of hypersonic aircraft models received in methodological tests are also presented. The tunnel experiments have been carried out in the Mach number range M∞=2-6.

  12. Evaluation of pressure and durability of a low-cost wheelchair cushion designed for developing countries.

    PubMed

    Guimaraes, Evandro; Mann, William C

    2003-06-01

    Pressure sores are a medical problem for wheelchair users worldwide. In developing countries this problem is more critical because of lack of access to specialized technologies and medical assessment. Seat cushions to relieve pressure represent one of best ways to prevent pressure sores for people with spinal cord injury, amputation, cerebral palsy, and other disabilities that require use of wheelchairs for long periods of time. The purpose of this study was to evaluate the performance of a low cost cushion, called the Tuball, designed for low-income communities in developing countries. The Tuball is made from bicycle inner tubes and plastic balls. Its durability and pressure-relieving characteristics were compared with the ROHOTM cushion and the foam cushions now used in Brazil. A sample of 30 participants tested the three cushions: 15 persons with paraplegia and 15 matched able-bodied persons evaluated the capacity of the cushions to distribute pressure. This study also addressed the use of samples of persons without disabilities to test wheelchair cushions.The Tuball cushion provided significantly better pressure distribution than the foam cushion. A t-test was used to compare disabled persons and non-disabled persons as samples in testing cushions. No difference between pressure distribution between non-disabled and disabled participants was found in testing the ROHO cushion or the foam cushion. However, both capacities of pressure distribution and HICPR varied between non-disabled and disabled participants for the Tuball cushion. To determine the useful life of the Tuball cushion, a fatigue test was conducted to simulate sitting and transfer. Both the Tuball and ROHO cushions withstood the equivalent of at least 1 year of use, whereas the foam cushion broke down. PMID:12799609

  13. 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

  14. 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.

  15. 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.

  16. 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

  17. A model to assess the comfort of automotive seat cushions.

    PubMed

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed.

  18. A model to assess the comfort of automotive seat cushions.

    PubMed

    Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

    2014-01-01

    A large number of independent and interacting factors affect seating comfort such as seat shape, stability, lumbar support and seat height. Although many subjective comfort studies have been conducted, few of them considered seating comfort from its subassembly level. This paper analyzed the automotive seat cushion designed with geared four-bar linkage for the seat height adjustment. The operation torque and lift distance of this mechanism was investigated as 2 major comfort factors. Ten cushions with this kind of design in the market were compared and assessed. PMID:25189755

  19. 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

  20. 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.

  1. 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

  2. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations... Minimum Property Standards § 200.948 Building product standards and certification program for carpet cushion. (a) Applicable standards. (1) All carpet cushion shall be designed, manufactured, and tested...

  3. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations... Minimum Property Standards § 200.948 Building product standards and certification program for carpet cushion. (a) Applicable standards. (1) All carpet cushion shall be designed, manufactured, and tested...

  4. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations... Minimum Property Standards § 200.948 Building product standards and certification program for carpet cushion. (a) Applicable standards. (1) All carpet cushion shall be designed, manufactured, and tested...

  5. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations... Minimum Property Standards § 200.948 Building product standards and certification program for carpet cushion. (a) Applicable standards. (1) All carpet cushion shall be designed, manufactured, and tested...

  6. 24 CFR 200.948 - Building product standards and certification program for carpet cushion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... certification program for carpet cushion. 200.948 Section 200.948 Housing and Urban Development Regulations... Minimum Property Standards § 200.948 Building product standards and certification program for carpet cushion. (a) Applicable standards. (1) All carpet cushion shall be designed, manufactured, and tested...

  7. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets.

  8. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets. PMID:19406910

  9. 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 Australia—using the existing WTF launching and tracking facilities and sponsor-provided laser pointing and tracking and illumination systems.

  10. Ground moving target geo-location from monocular camera mounted on a micro air vehicle

    NASA Astrophysics Data System (ADS)

    Guo, Li; Ang, Haisong; Zheng, Xiangming

    2011-08-01

    The usual approaches to unmanned air vehicle(UAV)-to-ground target geo-location impose some severe constraints to the system, such as stationary objects, accurate geo-reference terrain database, or ground plane assumption. Micro air vehicle(MAV) works with characteristics including low altitude flight, limited payload and onboard sensors' low accuracy. According to these characteristics, a method is developed to determine the location of ground moving target which imaged from the air using monocular camera equipped on MAV. This method eliminates the requirements for terrain database (elevation maps) and altimeters that can provide MAV's and target's altitude. Instead, the proposed method only requires MAV flight status provided by its inherent onboard navigation system which includes inertial measurement unit(IMU) and global position system(GPS). The key is to get accurate information on the altitude of the ground moving target. First, Optical flow method extracts background static feature points. Setting a local region around the target in the current image, The features which are on the same plane with the target in this region are extracted, and are retained as aided features. Then, inverse-velocity method calculates the location of these points by integrated with aircraft status. The altitude of object, which is calculated by using position information of these aided features, combining with aircraft status and image coordinates, geo-locate the target. Meanwhile, a framework with Bayesian estimator is employed to eliminate noise caused by camera, IMU and GPS. Firstly, an extended Kalman filter(EKF) provides a simultaneous localization and mapping solution for the estimation of aircraft states and aided features location which defines the moving target local environment. Secondly, an unscented transformation(UT) method determines the estimated mean and covariance of target location from aircraft states and aided features location, and then exports them for the

  11. 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.

  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

  13. 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.

  14. 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.

  15. 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.

  16. 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⁻¹, operate in a Reynolds number regime of 10⁵ 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

  17. 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⁻¹, operate in a Reynolds number regime of 10⁵ 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.

  18. 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

  19. 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.

  20. Design of flapping wings for application to single active degree of freedom micro air vehicles

    NASA Astrophysics Data System (ADS)

    Chang, Kelvin Thomas

    This dissertation covers an experimental program to understand how wing compliance influences the performance of flapping micro air vehicle wings. The focus is the design of a membraned flapping wing for a single active degree of freedom mechanism, looking to maximize thrust performance in hover conditions. The optimization approach is unique in that experiments were the chosen engine as opposed to a computation model; this is because of the complexity involved in hover-mode flapping aerodynamics. The flapping mechanism and manufacturing process for fabricating the wings were carefully developed. The uncertainty in the thrust measurement was identified and reduced by implementing precision machining and repeatable techniques for fabrication. This resulted in a reduction of the manufacturing coefficient of variation from 16.8% to 2.6%. Optimization was then conducted for a single objective (Maximize thrust), using a three parameter design space, finding the highest thrust performance in wings with high aspect ratio; then, a multi-objective optimization was conducted with two objectives (Thrust and Power) and a four parameter space. The research then shifted focus to identifying the stiffness and deformation characteristics of high performance wing designs. Static stiffness measurements with a simple line load suggested that high chordwise stiffness or lower spanwise stiffness would be favorable for aerodynamic performance. To explore more components of the deformation, a full-field imaging technique was used and a uniform load was substituted to engage with the membrane. It was found that there is a range of torsional compliance where the wing is most efficient especially at higher flapping frequencies. The final component of the study was the dynamic deformation measurement. The two system, four camera digital image correlation setup uses stroboscopic measurement to capture the wing deformation. The phase shift between the twist and stroke, and the tip deflection

  1. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    PubMed

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles.

  2. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    PubMed

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. PMID:27219504

  3. 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 Øland, 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.

  4. 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 Øland, 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

  5. 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

  6. 78 FR 11122 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-15

    ... Vehicle Emissions Budgets for the Pennsylvania Counties in the Philadelphia-Wilmington, PA-NJ-DE 1997 Fine... Motor Vehicle Emissions Budgets (MVEBs) for the Pennsylvania counties in the Philadelphia-Wilmington, PA... Philadelphia Area) to reflect the use of the most recent version of the Motor Vehicle Emission Simulator...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Roof Modelling Potential of Unmanned Air Vehicle Point Clouds with Respect to Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Karakis, Serkan; Gunes Sefercik, Umut; Atalay, Can

    2016-07-01

    In parallel with the improvement of laser scanning technologies, dense point clouds which provide the detailed description of terrain and non-terrain objects became indispensable for remotely-sensed data users. Owing to the large demand, besides laser scanning, point clouds were started to achieve using photogrammetric images. Unmanned air vehicle (UAV) images are one of the most preferred data for creating dense point clouds by the advantage of low cost, rapid and periodically gain. In this study, we tried to assess the roof modelling potential of UAV point clouds by comparing three dimensional (3D) roof models produced from UAV and terrestrial laser scanning (TLS) point clouds. In the study, very popular low cost action camera SJ4000 and Faro Laser Scanner Focus3D X 330 were used to provide point clouds and the roof of Bulent Ecevit University Civil Aviation Academy building was utilized. For the validation of horizontal and vertical geolocation accuracies, standard deviation was used as the main indicator. The visual results demonstrated that UAV roof model is almost coherent with TLS roof model after the filtering-based refinement on noisy pixels and systematic bias correction. Moreover, the horizontal geolocation accuracy is approx. |5cm| both in X and Y directions and bias corrected vertical geolocation accuracy is approx. 17cm for zero roof slope.

  17. 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.

  18. 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.

  19. 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.

  20. GPS navigation algorithms for Autonomous Airborne Refueling of Unmanned Air Vehicles

    NASA Astrophysics Data System (ADS)

    Khanafseh, Samer Mahmoud

    Unmanned Air Vehicles (UAVs) have recently generated great interest because of their potential to perform hazardous missions without risking loss of life. If autonomous airborne refueling is possible for UAVs, mission range and endurance will be greatly enhanced. However, concerns about UAV-tanker proximity, dynamic mobility and safety demand that the relative navigation system meets stringent requirements on accuracy, integrity, and continuity. In response, this research focuses on developing high-performance GPS-based navigation architectures for Autonomous Airborne Refueling (AAR) of UAVs. The AAR mission is unique because of the potentially severe sky blockage introduced by the tanker. To address this issue, a high-fidelity dynamic sky blockage model was developed and experimentally validated. In addition, robust carrier phase differential GPS navigation algorithms were derived, including a new method for high-integrity reacquisition of carrier cycle ambiguities for recently-blocked satellites. In order to evaluate navigation performance, world-wide global availability and sensitivity covariance analyses were conducted. The new navigation algorithms were shown to be sufficient for turn-free scenarios, but improvement in performance was necessary to meet the difficult requirements for a general refueling mission with banked turns. Therefore, several innovative methods were pursued to enhance navigation performance. First, a new theoretical approach was developed to quantify the position-domain integrity risk in cycle ambiguity resolution problems. A mechanism to implement this method with partially-fixed cycle ambiguity vectors was derived, and it was used to define tight upper bounds on AAR navigation integrity risk. A second method, where a new algorithm for optimal fusion of measurements from multiple antennas was developed, was used to improve satellite coverage in poor visibility environments such as in AAR. Finally, methods for using data-link extracted

  1. 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.

  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. 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,...

  4. Structural studies of polymer-cushioned lipid bilayers.

    PubMed

    Majewski, J; Wong, J Y; Park, C K; Seitz, M; Israelachvili, J N; Smith, G S

    1998-11-01

    The structure of softly supported polymer-cushioned lipid bilayers, prepared in two different ways at the quartz-solution interface, were determined using neutron reflectometry. The polymer cushion consisted of a thin layer of branched, cationic polyethyleneimine (PEI), and the bilayers were formed by adsorption of small unilamellar dimyristoylphosphatidylcholine (DMPC) vesicles. When vesicles were first allowed to adsorb to a bare quartz substrate, an almost perfect bilayer formed. When the polymer was then added to the aqueous solution, it appeared to diffuse beneath this bilayer, effectively lifting it from the substrate. In contrast, if the polymer layer is adsorbed first to the bare quartz substrate followed by addition of vesicles to the solution, there is very little interaction of the vesicles with the polymer layer, and the result is a complex structure most likely consisting of patchy multilayers or adsorbed vesicles.

  5. Field test of the Electric Fuel{trademark} zinc-air refuelable battery system for electric vehicles

    SciTech Connect

    Goldstein, J.R.; Koretz, B.; Harats, Y.

    1996-12-31

    The Electric Fuel Limited (EFL) zinc-air refuelable battery system will be tested over the next two years in a number of electric vehicle demonstration projects, the largest of which is an $18-million, 64-vehicle, two-year test sponsored chiefly by Deutsche Post AG (the German Post Corporation). The German field test is the largest-ever EV fleet test of a single advanced-battery technology. It also represents a marked departure from other EV test and demonstration programs, in that it is being sponsored not by government or electric utility interests, but by large fleet operators committed to shifting significant proportions of their vehicles to electric over the next 5--10 years. The Electric Fuel battery has specific energy of 200 Wh/kg, an achievement that allows electric vehicles to go as far on a charge as conventionally fueled vehicles go on a tank of gasoline. Fast, convenient refueling eliminates the need for lengthy electrical recharging, and clean, centralized zinc regeneration plants ensure the most efficient and environment-friendly use of energy resources.

  6. 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.

  7. 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.

  8. 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.

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

    NASA Astrophysics Data System (ADS)

    Michel, Silvain; Dürager, 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. 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.

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

    NASA Astrophysics Data System (ADS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-12-01

    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.

  12. 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.

  13. 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.

  14. 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.

  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

    ... attainment date (77 FR 11739). EPA issued a 1-year attainment date extension (i.e., from June 2010 to June..., 2011 attainment date (77 FR 17341). EPA issued a 1-year attainment date extension (i.e., from June 2010... subsequent model year passenger cars, light trucks, and medium-duty vehicles having a gross vehicle...

  16. 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

  17. 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

  18. High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

    NASA Astrophysics Data System (ADS)

    Zhang, Shaojun; Wu, Ye; Huang, Ruikun; Wang, Jiandong; Yan, Han; Zheng, Yali; Hao, Jiming

    2016-08-01

    Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach) to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet - Macau, EMBEV-Macau), this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model) model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other vehicle-populated cities

  19. Development and evaluation of a new contoured cushion system with an optimized normalization algorithm.

    PubMed

    Li, Sujiao; Zhang, Zhengxiang; Wang, Jue

    2014-01-01

    Prevention of pressure sores remains a significant problem confronting spinal cord injury patients and the elderly with limited mobility. One vital aspect of this subject concerns the development of cushions to decrease pressure ulcers for seated patients, particularly those bound by wheelchairs. Here, we present a novel cushion system that employs interface pressure distribution between the cushion and the buttocks to design custom contoured foam cushion. An optimized normalization algorithm was proposed, with which interface pressure distribution was transformed into the carving depth of foam cushions according to the biomechanical characteristics of the foam. The shape and pressure-relief performance of the custom contoured foam cushions was investigated. The outcomes showed that the contoured shape of personalized cushion matched the buttock contour very well. Moreover, the custom contoured cushion could alleviate pressure under buttocks and increase subjective comfort and stability significantly. Furthermore, the fabricating method not only decreased the unit production cost but also simplified the procedure for manufacturing. All in all, this prototype seat cushion would be an effective and economical way to prevent pressure ulcers. PMID:25227054

  20. FOG-2 Attenuates Endothelial-to-Mesenchymal Transformation in the Endocardial Cushions of the Developing Heart

    PubMed Central

    Flagg, Alleda E.; Earley, Judy U.; Svensson, Eric C.

    2007-01-01

    Development of the heart valves is a complex process that relies on the successful remodeling of endocardial cushions. This process is dependent on a number of transcriptional regulators, including GATA4 and its interacting partner FOG-2. We have previously shown that the endocardial cushions in FOG-2 deficient mice are hyperplastic and fail to remodel appropriately, suggesting a defect late in endocardial cushion development. To elucidate this defect, we examined the later steps in endocardial cushion development including mesenchymal cell proliferation, differentiation, and apoptosis. We also measured myocardialization and endothelial-to-mesenchymal transformation (EMT) using previously described in vitro assays. We found no difference in the ability of the endocardial cushions to undergo myocardialization or in the rates of mesenchymal cell proliferation, differentiation, or apoptosis in the FOG-2 deficient cushions when compared to wild-type controls. However, using a collagen gel invasion assay, we found a 75% increase in outflow tract cushion EMT and a 35% increase in atrioventricular cushion EMT in the FOG-2 deficient mice when compared with wild-type mice. Taken together with GATA4’s known role in promoting EMT, these results suggest that FOG-2 functions in cardiac valve formation is as an attenuator of EMT by attenuating GATA4 activity within the developing endocardial cushions. PMID:17274974

  1. 76 FR 44829 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ... Speed in ft/sec t r = Air pressure rise time in seconds a f = Steady-state deceleration in ft/sec For the final rule, the agency selected an air pressure rise time of 0.45 seconds, which is equal to the... Standards; Air Brake Systems AGENCY: National Highway Traffic Safety Administration (NHTSA), Department...

  2. Aggregated GPS tracking of vehicles and its use as a proxy of traffic-related air pollution emissions

    NASA Astrophysics Data System (ADS)

    Chen, Shimon; Bekhor, Shlomo; Yuval; Broday, David M.

    2016-10-01

    Most air quality models use traffic-related variables as an input. Previous studies estimated nearby vehicular activity through sporadic traffic counts or via traffic assignment models. Both methods have previously produced poor or no data for nights, weekends and holidays. Emerging technologies allow the estimation of traffic through passive monitoring of location-aware devices. Examples of such devices are GPS transceivers installed in vehicles. In this work, we studied traffic volumes that were derived from such data. Additionally, we used these data for estimating ambient nitrogen dioxide concentrations, using a non-linear optimisation model that includes basic dispersion properties. The GPS-derived data show great potential for use as a proxy for pollutant emissions from motor-vehicles.

  3. 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.

  4. 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.

  5. 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.

  6. 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).

  7. 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 ...

  8. Ascent performance of an air-breathing horizontal-takeoff launch vehicle

    NASA Astrophysics Data System (ADS)

    Powell, Richard W.; Shaughnessy, John D.; Cruz, Christopher I.; Naftel, J. C.

    1991-08-01

    Simulations are conducted to investigate a proposed NASA launch vehicle that is fully reusable, takes off horizontally, and uses airbreathing propulsion in a single stage. The propulsion model is based on a cycle analysis method, and the vehicle is assumed to be a rigid structure with distributed fuel, operating under a range of atmospheric conditions. The program to optimize simulated trajectories (POST) is modified to include a predictor-corrector guidance capability and then used to generate the trajectories. Significant errors are encountered during the unpowered coast phase due to uncertainty in the atmospheric density profile. The amount of ascent propellant needed is shown to be directly related to the thrust-vector angle and the location of the center of gravity of the vehicle because of the importance of aim-drag losses to total ideal velocity.

  9. Determination of the volatile fraction of phosphorus flame retardants in cushioning foam of upholstered furniture: towards respiratory exposure assessment.

    PubMed

    Ghislain, Mylène; Beigbeder, Joana; Dumazert, Loïc; Lopez-Cuesta, José-Marie; Lounis, Mohammed; Leconte, Stéphane; Desauziers, Valérie

    2016-10-01

    The purpose of this paper was to highlight potential exposure in indoor air to phosphorus flame retardants (PFRs) due to their use in upholstered furniture. For that, an analytical method of PFRs by headspace coupled to solid-phase micro-extraction (HS-SPME) was developed on cushioning foams in order to determine the PFRs' volatile fraction in the material. Tests on model foams proved the feasibility of the method. The average repeatability (RSD) is 6.3 % and the limits of detection range from 0.33 to 1.29 μg g(-1) of foam, depending on the PFRs. Results showed that some PFRs can actually be emitted in air, leading to a potential risk of exposure by inhalation. The volatile fraction can be high (up to 98 % of the total PFRs amount) and depends on the physicochemical properties of flame retardants, on the textural characteristics of the materials and on the temperature. The methodology developed for cushioning foams could be further applied to other types of materials and can be used to rate them according to their potential releases of phosphorus flame retardants.

  10. Determination of the volatile fraction of phosphorus flame retardants in cushioning foam of upholstered furniture: towards respiratory exposure assessment.

    PubMed

    Ghislain, Mylène; Beigbeder, Joana; Dumazert, Loïc; Lopez-Cuesta, José-Marie; Lounis, Mohammed; Leconte, Stéphane; Desauziers, Valérie

    2016-10-01

    The purpose of this paper was to highlight potential exposure in indoor air to phosphorus flame retardants (PFRs) due to their use in upholstered furniture. For that, an analytical method of PFRs by headspace coupled to solid-phase micro-extraction (HS-SPME) was developed on cushioning foams in order to determine the PFRs' volatile fraction in the material. Tests on model foams proved the feasibility of the method. The average repeatability (RSD) is 6.3 % and the limits of detection range from 0.33 to 1.29 μg g(-1) of foam, depending on the PFRs. Results showed that some PFRs can actually be emitted in air, leading to a potential risk of exposure by inhalation. The volatile fraction can be high (up to 98 % of the total PFRs amount) and depends on the physicochemical properties of flame retardants, on the textural characteristics of the materials and on the temperature. The methodology developed for cushioning foams could be further applied to other types of materials and can be used to rate them according to their potential releases of phosphorus flame retardants. PMID:27650437

  11. On aerodynamic modelling of an insect-like flapping wing in hover for micro air vehicles.

    PubMed

    Zbikowski, Rafał

    2002-02-15

    This theoretical paper discusses recent advances in the fluid dynamics of insect and micro air vehicle (MAV) flight and considers theoretical analyses necessary for their future development. The main purpose is to propose a new conceptual framework and, within this framework, two analytic approaches to aerodynamic modelling of an insect-like flapping wing in hover in the context of MAVs. The motion involved is periodic and is composed of two half-cycles (downstroke and upstroke) which, in hover, are mirror images of each other. The downstroke begins with the wing in the uppermost and rearmost position and then sweeps forward while pitching up and plunging down. At the end of the half-cycle, the wing flips, so that the leading edge points backwards and the wing's lower surface becomes its upper side. The upstroke then follows by mirroring the downstroke kinematics and executing them in the opposite direction. Phenomenologically, the interpretation of the flow dynamics involved, and adopted here, is based on recent experimental evidence obtained by biologists from insect flight and related mechanical models. It is assumed that the flow is incompressible, has low Reynolds number and is laminar, and that two factors dominate: (i) forces generated by the bound leading-edge vortex, which models flow separation; and (ii) forces due to the attached part of the flow generated by the periodic pitching, plunging and sweeping. The first of these resembles the analogous phenomenon observed on sharp-edged delta wings and is treated as such. The second contribution is similar to the unsteady aerodynamics of attached flow on helicopter rotor blades and is interpreted accordingly. Theoretically, the fluid dynamic description is based on: (i) the superposition of the unsteady contributions of wing pitching, plunging and sweeping; and (ii) adding corrections due to the bound leading-edge vortex and wake distortion. Viscosity is accounted for indirectly by imposing the Kutta condition

  12. Rotor hover performance and system design of an efficient coaxial rotary wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Bohorquez, Felipe

    2007-12-01

    Rotary-wing Micro air vehicles (MAVs) due to their unique hovering and low-speed flight capabilities are specially suited for missions that require operation in constrained spaces. Size restrictions force MAVs to operate in a low Reynolds number aerodynamic regime where viscous effects are dominant. This results in poor aerodynamic performance of conventional airfoils and rotor configurations. This dissertation explores the design issues that affect the hover performance of small-scale rotors and the implementation of a working coaxial MAV prototype. A computerized hover test stand was used for the systematic testing of single and coaxial small-scale rotors. Thin circular arcs were chosen for blade manufacturing because of their good aerodynamic characteristics at low Reynolds numbers, and simplified parameterization. Influence of airfoil geometry on single rotor hover performance was studied on untwisted rectangular blades. Non rectangular blades were used to study coupled airfoil and blade parameters. Tip tapered geometries were manufactured by removing material from baseline rectangular blades producing a coupling between blade planform, twist distribution, and spanwise airfoil shape. Performance gains were obtained by introducing large negative twist angles over short radial distances at the blade tips. A parametric study of the blade geometries resulted in maximum figures of merit of 0.65. Coaxial rotor performance at torque equilibrium was explored for different trims and operating conditions. It was found that the upper rotor was marginally affected by the lower one at spacings larger than 35% of the rotor radius, and that it produced about 60% of the total thrust. Experiments showed that power loading was maximized when higher collectives were used at the lower rotor, resulting in sizable differences in rotational speed between rotors. The CFD solver INS2d was used for a two-dimensional parametric aerodynamic study of circular arc airfoils. Lift, drag, and

  13. 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.

  14. Special problems and capabilities of high altitude lighter than air vehicles

    NASA Technical Reports Server (NTRS)

    Wessel, P. R.; Petrone, F. J.

    1975-01-01

    Powered LTA vehicles have historically been limited to operations at low altitudes. Conditions exist which may enable a remotely piloted unit to be operated at an altitude near 70,000 feet. Such systems will be launched like high altitude balloons, operate like nonrigid airships, and have mission capabilities comparable to a low altitude stationary satellite. The limited lift available and the stratospheric environment impose special requirements on power systems, hull materials and payloads. Potential nonmilitary uses of the vehicle include communications relay, environmental monitoring and ship traffic control.

  15. Cabin air temperature of parked vehicles in summer conditions: life-threatening environment for children and pets calculated by a dynamic model

    NASA Astrophysics Data System (ADS)

    Horak, Johannes; Schmerold, Ivo; Wimmer, Kurt; Schauberger, Günther

    2016-07-01

    In vehicles that are parked, no ventilation and/or air conditioning takes place. If a vehicle is exposed to direct solar radiation, an immediate temperature rise occurs. The high cabin air temperature can threaten children and animals that are left unattended in vehicles. In the USA, lethal heat strokes cause a mean death rate of 37 children per year. In addition, temperature-sensitive goods (e.g. drugs in ambulances and veterinary vehicles) can be adversely affected by high temperatures. To calculate the rise of the cabin air temperature, a dynamic model was developed that is driven by only three parameters, available at standard meteorological stations: air temperature, global radiation and wind velocity. The transition from the initial temperature to the constant equilibrium temperature depends strongly on the configuration of the vehicle, more specifically on insulation, window area and transmission of the glass, as well as on the meteorological conditions. The comparison of the model with empirical data showed good agreement. The model output can be applied to assess the heat load of children and animals as well as temperature-sensitive goods, which are transported and/or stored in a vehicle.

  16. 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.

  17. The design of passively athermalized narrow- and wide-field-of-view infrared objectives for the OBSERVER unmanned air vehicle

    NASA Astrophysics Data System (ADS)

    Simmons, Richard C.; Manning, Paul A.; Chamberlain, Trevor V.

    2004-12-01

    Some years ago QinetiQ introduced a short-range reconnaissance unmanned air vehicle (UAV), known as OBSERVER, which carried a visible three-camera sensor. To increase its versatility, a compatible infrared (IR) thermal imaging (TI) sensor was developed for the vehicle for operation in the 8-12mm waveband with a dual field of view function. The sensor incorporates a specially designed camera board, employing two IR lead scandium tantalate (PST) detectors based on UK un-cooled TI technology. Since no cooling engine is required for the detectors, the sensor module is very lightweight and hence well suited to its UAV application. So as to achieve the minimum possible payload for the vehicle, in addition to the lightweight detectors and electronics board, compact low mass optical solutions were devised for the camera objectives. These functioned at a relative aperture of f/1.0 and were designed to provide stable focus and imaging performance over a comparatively large temperature span (-10°C to + 50°C) to enable all weather operation. In order to achieve an athermalisation scheme devoid of elaborate electro-mechanical drives, thermally passive solutions were developed for the objectives in which the differing thermal characteristics of the components were designed to self-cancel optically. In this paper, the design and performance limitations of the optics are discussed and the procedure employed for establishing a thin lens pre-design for one of the objectives is described.

  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. Ozone variations through vehicle emissions reductions based on air quality monitoring data in Taipei City, Taiwan, from 1994 to 2003

    NASA Astrophysics Data System (ADS)

    Chang, Shuenn-Chin; Lee, Chung-Te

    The ozone (O 3) ambient air quality is evaluated using two indices in Taiwan: the daily maximum O 3 concentration (O 3, max ) greater than 120 ppb and the daily 8-h O 3 moving average (O 3, 8 h ) greater than 60 ppb. Results of air quality monitoring data from 1994 to 2003 in Taipei City indicate that the 99th percentile O 3, max was reduced, but those below the 90th percentile O 3, max obviously increased and days with O 3, 8 h greater than 60 ppb were doubled after the reduction of O 3 precursor emissions. Because of Taipei's unique vehicle emissions pattern in having more motorcycles than cars, Sunday, as compared to weekdays, has more reductions of non-methane hydrocarbons (NMHCs) than NO X. This results in Sunday O 3, max being lower than weekday O 3, max average for those days with O 3, max exceeding 80 ppb. On the contrary, if O 3, max is lower than 60 ppb, Sunday O 3, max is relatively higher than weekday O 3, max average, due to the reduced NO titration effect. In addition, our evaluations of O 3 levels with respect to the ambient air quality standards show that the number of Sundays with O 3, max greater than 120 ppb is fewer than the number average of weekdays with O 3, max exceeding 120 ppb for every month. Concerning O 3, 8 h , only in June, July, and August, when the meteorological conditions favor O 3 production, does the reduction of Sunday vehicle exhaust reduce the number of days with O 3,8h greater than 60 ppb. However, in September and October, the reduction of Sunday vehicle exhaust will increase the number of days. The results presented in this paper indicate that the O 3 pollution in Taipei City is VOC-limited. Thus, for a greater reduction in NMHCs, like the Sunday vehicle reduction in Taipei City, the upper percentile O 3, max is reduced more and those below the moderately high percentile O 3, max are increased less.

  20. 78 FR 19991 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... August 28, 2012 (77 FR 51930). The MVEBs were previously developed using Highway Mobile Source Emission..., 2002 Base Year portion of the 8/3/12 77 FR 51930 Emissions Inventory, Philadelphia-Wilmi 1/29/13 4/3/13... Vehicle Emissions Budgets for the Pennsylvania Counties in the Philadelphia-Wilmington, PA-NJ-DE 1997...

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

    PubMed Central

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

    2015-01-01

    This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system. PMID:27351020

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

    PubMed

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

    2015-01-01

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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. Unusual basal skull fracture in a vehicle equipped with an air bag.

    PubMed

    Bandstra, R A; Carbone, L S

    2001-09-01

    A woman who was the lap/shoulder belt-restrained driver of a car equipped with a full-size air bag was involved in an oblique frontal collision with a tractor-trailer combination. She was extremely out of position, i.e., witnessed to be slumped over the steering wheel before impact. This preimpact positioning led to fatal injuries resulting from the inflating air bag. Postmortem examination showed an unusual partial ring fracture of the base of the skull, which to the authors' knowledge has not previously been reported.

  9. Unusual basal skull fracture in a vehicle equipped with an air bag.

    PubMed

    Bandstra, R A; Carbone, L S

    2001-09-01

    A woman who was the lap/shoulder belt-restrained driver of a car equipped with a full-size air bag was involved in an oblique frontal collision with a tractor-trailer combination. She was extremely out of position, i.e., witnessed to be slumped over the steering wheel before impact. This preimpact positioning led to fatal injuries resulting from the inflating air bag. Postmortem examination showed an unusual partial ring fracture of the base of the skull, which to the authors' knowledge has not previously been reported. PMID:11563734

  10. An audit of cushioned diabetic footwear: relation to patient compliance.

    PubMed

    Chantelau, E; Haage, P

    1994-01-01

    The recurrence rate of neuropathic foot ulcers is reported in 51 diabetic patients regularly attending a diabetic foot clinic. All of the patients were provided with protective footwear reducing peak plantar pressure at the forefoot area by 50% (versus normal shoes), and were followed up for up to 4 years. Compliance with this footwear was recorded by assessing the daily time of wearing protective or normal shoes, and compliance with foot care was recorded from the entries in the patients charts. The results of this observational study demonstrate that wearing protective shoes for > 60% of the daytime significantly (p = 0.0002) reduced the ulcer relapse rate by > 50% in comparison with shorter wearing times for these shoes. In addition, patients without ulcer relapses had foot care significantly more frequently than patients with relapse (p < 0.05). It is concluded that cushioned protective footwear in association with frequent foot care is essential in the prevention of neuropathic diabetic foot ulcer recurrence.

  11. HSI Guidelines Outline for the Air Vehicle Control Station. Version 2

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This document provides guidance to the FAA and manufacturers on how to develop UAS Pilot Vehicle Interfaces to safely and effectively integrate UASs into the NAS. Preliminary guidelines are provided for Aviate, Communicate, Navigate and Avoid Hazard functions. The pilot shall have information and control capability so that pilot-UA interactions are not adverse, unfavorable, nor compromise safety. Unfavorable interactions include anomalous aircraft-pilot coupling (APC) interactions (closed loop), pilot-involved oscillations (categories I, II or III), and non-oscillatory APC events (e.g., divergence). - Human Systems Integration Pilot-Technology Interface Requirements for Command, Control, and Communications (C3)

  12. Study of distribution and characteristics of the time average of pressure of a water cushion pool

    NASA Astrophysics Data System (ADS)

    Guo, Y. H.; Fu, J. F.

    2016-08-01

    When a dam discharges flood water, the plunging flow with greater kinetic energy, will scour the riverbed, resulting in erosion damage. In order to improve the anti-erosion capacity of a riverbed, the cushion pool created. This paper is based on turbulent jet theoryto deduce the semi-empirical formula of the time average of pressure in the impinging portion of the cushion pool. Additionally, MATLAB numerical is used to conduct a simulation analysis according to turbulent jet energy and watercushion depth when water floods into the water cushion pool, to determine the regularities of distribution and related characteristics.

  13. 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.

  14. 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.

  15. On the Application of Rapid Prototyping Technology for the Fabrication of Flapping Wings for Micro Air Vehicles

    NASA Astrophysics Data System (ADS)

    Kraemer, Kurtis Leigh

    Micro air vehicles (MAV) are a class of small uninhabited aircraft with dimensions less than 15 cm (6 in) and mass less than 500g (1.1 lbs). The aim of this research was to develop a fast, accurate, low-cost, and repeatable fabrication process for flapping MAV wings. Through the use of the RepRap Mendel open-source fused-deposition modeling (FDM) rapid prototyping machine ("3-D printer"), various wing prototypes were designed and fabricated using a bio-inspired approach. Testing of the aerodynamic performance of both real locust wings and the 3-D printed wing prototypes was performed through axial spin testing. Bending stiffness measurements were also performed on the 3-D printed wings. Through the use of open-source rapid prototyping technology, a fast and low-cost fabrication process for flapping MAV wings has been developed, out of which further understanding of flapping wing design and fabrication has been gained.

  16. 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..., Care, Treatment, and Transportation of Marine Mammals Transportation Standards § 3.114 Primary... safeguards (such as, but not limited to, cooling the animal with cold water, adding ice to...

  17. Control system considerations for an aluminum-air battery powered electric vehicle. Final report

    SciTech Connect

    Cox, L.E.; Hassman, G.V.; Post, S.F.

    1980-05-15

    The study established basic motor-controller requirements and trade-offs between 30-cell and 60-cell aluminum-air battery systems. A sample controller design was evolved and basic characteristics were evaluated. Advantages of a 60-cell battery system over a 30-cell were found in the areas of control system costs, weights, and efficiency.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. An investigation of drag reduction for tractor trailer vehicles with air deflector and boattail. Final report

    SciTech Connect

    Muirhead, V.U.

    1981-01-01

    A wind tunnel investigation was conducted to determine the influence of several physical variables on the aerodynamic drag of a trailer model. The physical variables included: a cab mounted wind deflector, boattail on trailer, flow vanes on trailer front, forced transition on trailer, and decreased gap between tractor and trailer. Tests were conducted at yaw angles (relative wind angles) of 0, 5, 10, 20, and 30 degrees and Reynolds numbers of 3.58 x 10 to the 5th power 6.12 x 10 to the 5th power based upon the equivalent diameter of the vehicles. The wind deflector on top of the cab produced a calculated reduction in fuel consumption of about 5 percent of the aerodynamic portion of the fuel budget for a wind speed of 15.3 km/hr (9.5 mph) over a wind angle range of 0 deg to 180 deg and for a vehicle speed of 88.5 km/hr (55 mph). The boattail produced a calculated 7 percent to 8 percent reduction in fuel consumption under the same conditions. The decrease in gap reduced the calculated fuel consumption by about 5 percent of the aerodynamic portion of the fuel budget.

  4. 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.

  5. 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).

  6. Thermodynamic rigid cushion loading indenter: a buttock-shaped temperature and humidity measurement system for cushioning surfaces under anatomical compression conditions.

    PubMed

    Ferguson-Pell, Martin; Hirose, Hideyuki; Nicholson, Graham; Call, Evan

    2009-01-01

    A method is described for measuring the heat and water vapor dissipation characteristics of wheelchair cushions and seating systems while under simulated loading conditions. Thermal interaction between the body and seating surfaces can result in elevated tissue temperature and moisture build-up, which may increase the risk of pressure ulcers associated with prolonged ischemia or due to macerative damage. Both the materials and geometry of commercial seating systems are thought to influence the body-support surface microclimate. A thermodynamic rigid cushion loading indenter (TRCLI) has been developed to simulate the thermal and loading conditions of the body on seating surfaces. Results are reported for 32 commercially available wheelchair cushions. The results differentiate the cushions into clusters of comparable properties that offer the potential for classification of support surfaces based on their heat and water vapor dissipation performance. This study has shown that deducing the heat and water vapor dissipation characteristics of a seating system from material physical properties is of limited value because of the influences of particular design features of combinations of materials. Testing of individual products with the use of the TRCLI can, however, reliably differentiate wheelchair cushions by their ability to dissipate heat and water vapor. PMID:20104417

  7. Visual Servoing of Quadrotor Micro-Air Vehicle Using Color-Based Tracking Algorithm

    NASA Astrophysics Data System (ADS)

    Azrad, Syaril; Kendoul, Farid; Nonami, Kenzo

    This paper describes a vision-based tracking system using an autonomous Quadrotor Unmanned Micro-Aerial Vehicle (MAV). The vision-based control system relies on color target detection and tracking algorithm using integral image, Kalman filters for relative pose estimation, and a nonlinear controller for the MAV stabilization and guidance. The vision algorithm relies on information from a single onboard camera. An arbitrary target can be selected in real-time from the ground control station, thereby outperforming template and learning-based approaches. Experimental results obtained from outdoor flight tests, showed that the vision-control system enabled the MAV to track and hover above the target as long as the battery is available. The target does not need to be pre-learned, or a template for detection. The results from image processing are sent to navigate a non-linear controller designed for the MAV by the researchers in our group.

  8. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    NASA Astrophysics Data System (ADS)

    Burke, A. Alan; Carreiro, Louis G.

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5 kW for 40 h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. a Vibrational Model of Open Celled Polyurethane Foam Automotive Seat Cushions

    NASA Astrophysics Data System (ADS)

    Patten, W. N.; Sha, S.; Mo, C.

    1998-10-01

    A mechanistic model of a seat cushion is developed. The work relates the kinematic motion of the seat to the geometric and constitutive properties of the cellular foam used in the seat. The model includes the influence of pneumatic damping caused by friction between the gas within the open-celled foam and matrix polymer. A continuous shape function is introduced to characterize the piecewise continuous stress-strain characteristic of flexible open-celled foam. After some simplification, a non-linear dynamic automotive seat cushion model is derived, which relies explicitly on the constitutive properties of polyurethane foams and on the geometry of the seat cushion. Experimental and analytical models of the two automotive seats are compared to verify the model. The comparisons indicate that the new model is able to predict the dynamic performance of an automotive seat cushion with fidelity.

  16. Effects of conventional and alternating cushion weight-shifting in persons with spinal cord injury

    PubMed Central

    Wu, Gary A.; Bogie, Kath M.

    2015-01-01

    A repeated-measures study of 13 adult full-time wheelchair users with spinal cord injury (SCI) was carried out to determine whether alternating-pressure air cushion (APAC) use compared with independent pressure relief (IPR) provides reliable, effective pressure relief for individuals with SCI. Bilateral mean ischial interface pressure (IP), transcutaneous oxygen tension (TcPO2), and unilateral laser Doppler blood flow were evaluated. Blood flow component contributions were determined using short-time Fourier transform (STFT)-based spectral analysis. IPR assessment was carried out at recruitment. Study participants then used an APAC for 2 wk every 3 mo for 18 mo. IPR weight-shifting decreased mean ischial IP (p < 0.05) and increased mean TcPO2 (p < 0.05). All variables rapidly returned to preintervention levels following weight-shifting except for the cardiac component of blood flow. APAC-induced weight-shifting decreased mean ischial IP (p < 0.05). Mean TcPO2 increased and was higher than for IPR. STFT analysis indicated that quiet sitting following APAC-induced weight-shifting produced a higher neurogenic component of blood flow than following IPR (p = 0.02). Thus, IPR positively affects multiple aspects of tissue health but produces transient improvements and must be repeated regularly. APAC activation dynamically and continuously alters IP distribution with more sustained positive tissue health effects. PMID:25629607

  17. Effects of conventional and alternating cushion weight-shifting in persons with spinal cord injury.

    PubMed

    Wu, Gary A; Bogie, Kath M

    2014-01-01

    A repeated-measures study of 13 adult full-time wheelchair users with spinal cord injury (SCI) was carried out to determine whether alternating-pressure air cushion (APAC) use compared with independent pressure relief (IPR) provides reliable, effective pressure relief for individuals with SCI. Bilateral mean ischial interface pressure (IP), transcutaneous oxygen tension (TcPO2), and unilateral laser Doppler blood flow were evaluated. Blood flow component contributions were determined using short-time Fourier transform (STFT)-based spectral analysis. IPR assessment was carried out at recruitment. Study participants then used an APAC for 2 wk every 3 mo for 18 mo. IPR weight-shifting decreased mean ischial IP (p < 0.05) and increased mean TcPO2 (p < 0.05). All variables rapidly returned to preintervention levels following weight-shifting except for the cardiac component of blood flow. APAC-induced weight-shifting decreased mean ischial IP (p < 0.05). Mean TcPO2 increased and was higher than for IPR. STFT analysis indicated that quiet sitting following APAC-induced weight-shifting produced a higher neurogenic component of blood flow than following IPR (p = 0.02). Thus, IPR positively affects multiple aspects of tissue health but produces transient improvements and must be repeated regularly. APAC activation dynamically and continuously alters IP distribution with more sustained positive tissue health effects. PMID:25629607

  18. Misuse of Booster Cushions – An Observation Study of Children’s Performance during Buckling Up

    PubMed Central

    Osvalder, Anna-Lisa; Bohman, Katarina

    2008-01-01

    Booster cushions are effective tools to protect children from injuries in car crashes, but there remains a large amount of misuse. The aim of this study was to assess potential misuse of booster cushions in an observational laboratory study, and to identify whether booster cushion design, age or clothing had any effect. 130 Swedish children from the ages of 4–12 years participated. Each child buckled up on an integrated and on an aftermarket booster cushion in the rear seat. The older children also buckled up with seat belt only. Interviews, observations and body measurements were performed. Time to buckle up and amount of belt slack were registered. Photographs were taken to document misuse. Results showed that 77% failed to perform correct belt routing on the aftermarket cushion, independent of age, although they were familiar with this system. The misuse rate for the integrated cushion was only 4%. No misuse was found for seat belt only. Few children tightened the belt. The belt slack increased when wearing winter jackets. This indicates the importance of adding pretensioners to the rear seat. Sled tests with HIII&TNO 6y dummies were also performed for the most frequent misuse situations found. The main conclusion is that an integrated booster cushion has many advantages compared to an aftermarket cushion regarding both safety and comfort. It is easy and quick to handle, has few possibilities for misuse, has an intuitive design, the buckling up sequence is equal to buckling up with an ordinary seat belt, and younger children can buckle up correctly. PMID:19026222

  19. Misuse of booster cushions - an observation study of children's performance during buckling up.

    PubMed

    Osvalder, Anna-Lisa; Bohman, Katarina

    2008-10-01

    Booster cushions are effective tools to protect children from injuries in car crashes, but there remains a large amount of misuse. The aim of this study was to assess potential misuse of booster cushions in an observational laboratory study, and to identify whether booster cushion design, age or clothing had any effect. 130 Swedish children from the ages of 4-12 years participated. Each child buckled up on an integrated and on an aftermarket booster cushion in the rear seat. The older children also buckled up with seat belt only. Interviews, observations and body measurements were performed. Time to buckle up and amount of belt slack were registered. Photographs were taken to document misuse. Results showed that 77% failed to perform correct belt routing on the aftermarket cushion, independent of age, although they were familiar with this system. The misuse rate for the integrated cushion was only 4%. No misuse was found for seat belt only. Few children tightened the belt. The belt slack increased when wearing winter jackets. This indicates the importance of adding pretensioners to the rear seat. Sled tests with HIII&TNO 6y dummies were also performed for the most frequent misuse situations found. The main conclusion is that an integrated booster cushion has many advantages compared to an aftermarket cushion regarding both safety and comfort. It is easy and quick to handle, has few possibilities for misuse, has an intuitive design, the buckling up sequence is equal to buckling up with an ordinary seat belt, and younger children can buckle up correctly. PMID:19026222

  20. 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

  1. 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.

  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 (ϕ) and pitch (θ) 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⁻¹.

  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. 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 (ϕ) and pitch (θ) 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⁻¹. PMID:23211685

  6. 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 ϕ0.75 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 ϕ3.2 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.

  7. 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.

  8. 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

  9. VisNAV 100: a robust, compact imaging sensor for enabling autonomous air-to-air refueling of aircraft and unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Katake, Anup; Choi, Heeyoul

    2010-01-01

    To enable autonomous air-to-refueling of manned and unmanned vehicles a robust high speed relative navigation sensor capable of proving high accuracy 3DOF information in diverse operating conditions is required. To help address this problem, StarVision Technologies Inc. has been developing a compact, high update rate (100Hz), wide field-of-view (90deg) direction and range estimation imaging sensor called VisNAV 100. The sensor is fully autonomous requiring no communication from the tanker aircraft and contains high reliability embedded avionics to provide range, azimuth, elevation (3 degrees of freedom solution 3DOF) and closing speed relative to the tanker aircraft. The sensor is capable of providing 3DOF with an error of 1% in range and 0.1deg in azimuth/elevation up to a range of 30m and 1 deg error in direction for ranges up to 200m at 100Hz update rates. In this paper we will discuss the algorithms that were developed in-house to enable robust beacon pattern detection, outlier rejection and 3DOF estimation in adverse conditions and present the results of several outdoor tests. Results from the long range single beacon detection tests will also be discussed.

  10. 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

    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

  11. 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

    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

  12. Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.

    PubMed

    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

  13. 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

  14. 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.

  15. 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

  16. 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).

  17. SIG: Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    NASA Technical Reports Server (NTRS)

    Feary, Michael; Palanque, Philippe; Martinie, Célia; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  18. 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.

  19. Dynamic output feedback control of a flexible air-breathing hypersonic vehicle via T-S fuzzy approach

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoxiang; Wu, Ligang; Hu, Changhua; Wang, Zhaoqiang; Gao, Huijun

    2014-08-01

    By utilising Takagi-Sugeno (T-S) fuzzy set approach, this paper addresses the robust H∞ dynamic output feedback control for the non-linear longitudinal model of flexible air-breathing hypersonic vehicles (FAHVs). The flight control of FAHVs is highly challenging due to the unique dynamic characteristics, and the intricate couplings between the engine and fight dynamics and external disturbance. Because of the dynamics' enormous complexity, currently, only the longitudinal dynamics models of FAHVs have been used for controller design. In this work, T-S fuzzy modelling technique is utilised to approach the non-linear dynamics of FAHVs, then a fuzzy model is developed for the output tracking problem of FAHVs. The fuzzy model contains parameter uncertainties and disturbance, which can approach the non-linear dynamics of FAHVs more exactly. The flexible models of FAHVs are difficult to measure because of the complex dynamics and the strong couplings, thus a full-order dynamic output feedback controller is designed for the fuzzy model. A robust H∞ controller is designed for the obtained closed-loop system. By utilising the Lyapunov functional approach, sufficient solvability conditions for such controllers are established in terms of linear matrix inequalities. Finally, the effectiveness of the proposed T-S fuzzy dynamic output feedback control method is demonstrated by numerical simulations.

  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

  1. Endocardial cushion defect associated with cor triatriatum sinistrum or supravalve mitral ring.

    PubMed

    Thilenius, O G; Vitullo, D; Bharati, S; Luken, J; Lamberti, J J; Tatooles, C; Lev, M; Carr, I; Arcilla, R A

    1979-12-01

    Clinical and angiographic or autopsy data, or both, on three children with a subdivided left atrium (cor triatriatum) and an associated endocardial cushion defect are reviewed. (One child had ostium primum defect, and two had complete atrioventricular [A-V] canal.) A fourth patient demonstrates the difficulties in differentiating subdivided left atrium from supravalve mitral stenosis in the presence of an endocardial cushion defect. The clinical findings are greatly influenced by the endocardial cushion defect. A pressure gradient between the pulmonary wedge and (left or right) ventricular end-diastolic pressures in patients with an endocardial cushion defect indicates pulmonary venous obstruction and should alert one to the possibility of these combined lesions. The exact diagnosis is made with injections of angiographic contrast medium into the proximal and distal left atrial chambers, to documented the respective relations of the pulmonary veins, left atrial appendage and A-V valves to these atrial chambers. All three patients with an endocardial cushion defect and a subdivided left atrium had an associated patent ductus arteriosus. The common association of subdivided left atrium with intracardiac, pulmonary venous and aortic anomalies is again demonstrated.

  2. Numerical simulation on the seismic absorption effect of the cushion in rigid-pile composite foundation

    NASA Astrophysics Data System (ADS)

    Han, Xiaolei; Li, Yaokun; Ji, Jing; Ying, Junhao; Li, Weichen; Dai, Baicheng

    2016-06-01

    In order to quantitatively study the seismic absorption effect of the cushion on a superstructure, a numerical simulation and parametric study are carried out on the overall FEA model of a rigid-pile composite foundation in ABAQUS. A simulation of a shaking table test on a rigid mass block is first completed with ABAQUS and EERA, and the effectiveness of the Drucker-Prager constitutive model and the finite-infinite element coupling method is proved. Dynamic time-history analysis of the overall model under frequent and rare earthquakes is carried out using seismic waves from the El Centro, Kobe, and Bonds earthquakes. The different responses of rigid-pile composite foundations and pile-raft foundations are discussed. Furthermore, the influence of thickness and modulus of cushion, and ground acceleration on the seismic absorption effect of the cushion are analyzed. The results show that: 1) the seismic absorption effect of a cushion is good under rare earthquakes, with an absorption ratio of about 0.85; and 2) the seismic absorption effect is strongly affected by cushion thickness and ground acceleration.

  3. Inflorescences of alpine cushion plants freeze autonomously and may survive subzero temperatures by supercooling.

    PubMed

    Hacker, Jürgen; Ladinig, Ursula; Wagner, Johanna; Neuner, Gilbert

    2011-01-01

    Freezing patterns in the high alpine cushion plants Saxifraga bryoides, Saxifraga caesia, Saxifraga moschata and Silene acaulis were studied by infrared thermography at three reproductive stages (bud, anthesis, fruit development). The single reproductive shoots of a cushion froze independently in all four species at every reproductive stage. Ice formation caused lethal damage to the respective inflorescence. After ice nucleation, which occurred mainly in the stalk or the base of the reproductive shoot, ice propagated throughout that entire shoot, but not into neighboring shoots. However, anatomical ice barriers within cushions were not detected. The naturally occurring temperature gradient within the cushion appeared to interrupt ice propagation thermally. Consequently, every reproductive shoot needed an autonomous ice nucleation event to initiate freezing. Ice nucleation was not only influenced by minimum temperatures but also by the duration of exposure. At moderate subzero exposure temperatures (-4.3 to -7.7 °C) the number of frozen inflorescences increased exponentially. Due to efficient supercooling, single reproductive shoots remained unfrozen down to -17.4 °C (cooling rate 6 K h⁻¹). Hence, the observed freezing pattern may be advantageous for frost survival of individual inflorescences and reproductive success of high alpine cushion plants, when during episodic summer frosts damage can be avoided by supercooling.

  4. 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.

  5. 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.

  6. Evaluation of on-road vehicle CO and NOx National Emission Inventories using an urban-scale source-oriented air quality model

    NASA Astrophysics Data System (ADS)

    Kota, Sri Harsha; Zhang, Hongliang; Chen, Gang; Schade, Gunnar W.; Ying, Qi

    2014-03-01

    The MOBILE6.2 model was replaced by the Motor Vehicle Emission Simulator (MOVES) in 2012 as an official tool recommended by the United States Environmental Protection Agency (US EPA) to predict vehicular pollutant emission factors. In this study, on-road vehicle emission inventories of CO and NOx for Southeast Texas generated by MOVES and MOBILE6.2 in two versions of the 2005 National Emission Inventory (NEI) were studied by comparing predicted CO and NOx using the EPA's Community Multiscale Air Quality (CMAQ) Model incorporated with a source-oriented gas phase chemical mechanism with measurements made at six urban and industrial sites in Southeast Texas. The source tracing technique allows direct determination of contributions of on-road vehicles to overall CO and NOx concentrations and identification of ambient concentration measurements which are mostly impacted by vehicle emissions. By grouping the fractional bias (FB) values of the hourly predictions based on vehicle contributions to total CO or NOx concentrations, clear trends in the FB were observed, indicating systematic biases in the emission inventory for these species. Data points dominated by vehicle emissions suggest that surface CO concentrations due to vehicle exhaust are significantly over-estimated by a factor of 2 using either MOVES or MOBILE6.2. NOx concentrations are overestimated by approximately 20-35% and 70% by using the MOBILE6.2 and MOVES emissions, respectively. Emission scaling runs show that a domain-wide reduction of MOBILE6.2 CO emissions by 60% and NOx emissions by 15-25% leads to better model performance of exhaust CO and NOx concentrations in the current study.

  7. 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.

  8. Examples of the application of the cause-effect ergonomic evaluation model to the wheelchair cushions.

    PubMed

    Barberà-Guillem, Ricard; Page, Álvaro; Laparra, José; Durà, 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

  9. 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

  10. Friction and lubrication in cushion form bearings for artificial hip joints.

    PubMed

    Auger, D D; Dowson, D; Fisher, J; Jin, Z M

    1993-01-01

    Two hip joint prostheses were designed and constructed to be elastohydrodynamically equivalent producing approximately equal initial contact areas and theoretical film thicknesses. One was made from conventional UHMWPE (ultra-high molecular weight polyethylene) and the other was a cushion component which had a low modulus layer introduced into the joint space. Friction measurements were carried out on a pendulum simulator apparatus and the two joints were compared. In addition the experimental results were compared with theoretical values of friction predicted from elastohydrodynamic lubrication theory. Values for the friction factor at peak load and peak velocity in the cushion cup (0.003-0.009) were much lower than in the UHMWPE cup (0.017-0.042). The low friction values in the cushion cup are consistent with fluid film lubrication in the contact with the thin lubricating film being preserved by microelastohydrodynamic action.

  11. Examples of the application of the cause-effect ergonomic evaluation model to the wheelchair cushions.

    PubMed

    Barberà-Guillem, Ricard; Page, Álvaro; Laparra, José; Durà, 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.

  12. Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009.

    PubMed

    Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

    2014-07-01

    On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO(x)), and volatile organic compounds (VOCs) during 1995-2009 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, NO(x), and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995-2009 period despite an increase in total vehicle distance traveled. The CO and NO(x) emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO(x) 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 NO(x), 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 NO(x) 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 NO(x) 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

  13. 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

  14. Applying ISO 16840-2 Standard to differentiate impact force dissipation characteristics of selection of commercial wheelchair cushions.

    PubMed

    Ferguson-Pell, Martin; Ferguson-Pell, Grace; Mohammadi, Farhood; Call, Evan

    2015-01-01

    Results from applying the International Organization for Standardization (ISO) 16840-2 test method for determining the impact damping characteristics of 35 wheelchair cushions plus a high resilience (HR70) polyurethane reference foam sample are reported. The generation of impact forces when a wheelchair user either transfers onto a cushion or the wheelchair encounters rough terrain or bumps down a step can endanger the viability of tissues, especially if these forces occur repeatedly. The results demonstrate significant differences in the impact force dissipation characteristics of different cushion products but do not reliably identify differences in performance that can be attributed to descriptive information about cushion composition alone. Instead, these results demonstrate that the materials, proprietary design, and construction features of wheelchair cushions in combination dictate impact force dissipation properties. The results of a cluster analysis are used to generate a model that can be used to compare the impact damping properties obtained from the ISO 16840-2 test method with those of a range of cushions and the reference cushion. Manufacturers will therefore be able to provide users and clinicians with information about the impact force dissipation properties of the cushions that will enable them to make more informed product choices for achieving improved comfort and to protect skin integrity. PMID:26230038

  15. 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

  16. 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.

  17. Patterns of correlation between vehicle occupant seat pressure and anthropometry.

    PubMed

    Paul, Gunther; Daniell, Nathan; Fraysse, François

    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.

  18. 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.…

  19. 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

  20. 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