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1

Nuclear air cushion vehicles  

NASA Technical Reports Server (NTRS)

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.

Anderson, J. L.

1973-01-01

2

Air cushion vehicles: A briefing  

NASA Technical Reports Server (NTRS)

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.

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

1971-01-01

3

Open tube guideway for high speed air cushioned vehicles  

NASA Technical Reports Server (NTRS)

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.

Goering, R. S. (inventor)

1974-01-01

4

Creating new cities through the large air-cushion vehicle.  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

5

Operational noise data for the LACV-30 air cushion vehicle  

NASA Astrophysics Data System (ADS)

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

Schomer, P. D.

1985-03-01

6

Air cushion landing system  

NASA Technical Reports Server (NTRS)

Static and dynamic performance of air cushion landing system is simulated in computer program that treats four primary ACLS subsystems: fan, feeding system, trunk, and cushion. Configuration of systems is sufficiently general to represent variety of practical designs.

Boghami, K. M.; Captain, K. M.; Fish, R. B.

1978-01-01

7

Air cushion landing system stability study  

NASA Astrophysics Data System (ADS)

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.

Burton, T. D.

1981-02-01

8

Air cushioning in drop impact  

NASA Astrophysics Data System (ADS)

Liquid drops impacting on solid surfaces deform under the influence of the ambient gas that needs to be squeezed out before a true solid-liquid contact can be established. We demonstrate experimentally the existence of this theoretically predicted air layer and follow its evolution with time for moderate impact speeds (We ˜ 1 10) using reflection interference microscopy with a thickness resolution of approximately 10nm. For a wide range of fluid properties (?, ?, ?) we find a very robust generic behavior that includes the predicted formation of a dimple in the center of the drop with a local minimum of the air film thickness at its boundary. Depending on We as well as the fluid properties, a skating layer of more or less constant thickness as well as a second local minimum of the air film thickness farther away from the drop center develop in time. Eventually, solid-liquid contact is generated via random nucleation event. The nucleation spot spreads across the drop-substrate interface within a few milliseconds. This process can lead to the entrapment of an air bubble.

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

2011-11-01

9

Braking and cornering studies on an air cushion landing system  

NASA Technical Reports Server (NTRS)

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

Daugherty, R. H.

1983-01-01

10

Air-cushion tankers for Alaskan North Slope oil  

NASA Technical Reports Server (NTRS)

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.

Anderson, J. L.

1973-01-01

11

Experimental and analytical studies of advanced air cushion landing systems  

NASA Technical Reports Server (NTRS)

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.

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

12

Reduced energy and volume air pump for a seat cushion  

DOEpatents

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.

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

1997-08-19

13

Reduced energy and volume air pump for a seat cushion  

DOEpatents

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.

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

1997-01-01

14

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

PubMed

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

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

1975-01-01

15

A review on the aviation piston engine power assembly for the air cushion boat  

NASA Astrophysics Data System (ADS)

The aviation piston engine has a suitable power rating. The weight of the air cushion boat developed early was rather small, mostly ranging from 2 to 4 tons. The power rating of the air cushion boat is about 100 to 135 horsepower/ton. According to this, a single engine's power rating ranges from 200 to 500 horsepower. It is well known that this is exactly the most common power rating of an aviation piston engine (and an air-cooled diesel engine).

Jianzhang, Zhu

1986-09-01

16

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

PubMed

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

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

2014-06-01

17

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

PubMed Central

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

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

2014-01-01

18

Characteristics of an Air Cushion Landing System incorporating an inelastic trunk  

NASA Technical Reports Server (NTRS)

A series of static and dynamic tests performed on an Air Cushion Landing System (ACLS) incorporating inelastic trunk are described. The tests were performed on an apparatus which had provisions to isolate heave-pitch and roll motion on the prototype cushion. The results of the test show that the sides of the trunk behave differently from the trunk ends. The tests also demonstrate that the current ACLS designs suffer from low heave damping, low roll stiffness and fan stall problems.

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

1978-01-01

19

Air cushioning in droplet impact. II. Experimental characterization of the air film evolution  

NASA Astrophysics Data System (ADS)

A liquid drop approaching a solid surface deforms substantially under the influence of the ambient air which needs to be squeezed out before the liquid can actually touch the solid. We use nanometer- and microsecond-resolved dual wavelength interferometry described in Part I (also published in this issue) to reveal the complex spatial and temporal evolution of the squeezed air layer. In low-velocity droplet impact, i.e., We numbers of order unity, the confined air layer below the droplet develops two local minima in thickness. We quantitatively measure the evolution of the droplet bottom interface and find that surface tension determines the air film thickness below the first kink, after which fluid is diverted outward to form a second even sharper kink. Depending on We, one of the two kinks approaches the surface more closely forming liquid-solid contact. The early time spreading of liquid-solid contact is controlled by the capillary driving force and the inertia of the liquid. The cushioned air film geometry, i.e., a flat micrometer-thin gap, induces an increase of the spreading velocity; the contact area first spreads over the cushioned region, only then followed by radial spreading. This spreading mechanism can lead to the entrapment of one or more air bubbles.

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

2015-01-01

20

Speed control with end cushion for high speed air cylinder  

DOEpatents

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.

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

1991-01-01

21

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

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

22

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

PubMed

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. PMID:21890395

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

2012-04-01

23

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

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

24

Do pressure relief cushions really relieve pressure?  

PubMed

In a laboratory setting, interface pressures of 29 cushions and a sheepskin were measured on 20 healthy volunteers. Each participant was seated in an upright posture with their back against the back of the chair, hands resting on the lap, knees bent at an angle of 90 degrees, and feet resting on the floor. Only 13 cushions had any pressure-reducing effect. Gel cushions and sheepskins appear to have no pressure-reducing effect. The category of foam includes both cushions that reduce interface pressure very well and cushions that increase interface pressure. The lowest interface pressures were measured on air cushions and on some foam cushions. PMID:10804896

Defloor, T; Grypdonck, M H

2000-04-01

25

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)

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.

Thompson, W. C.

1973-01-01

26

Piloting Of Unmanned Air Vehicles  

NASA Astrophysics Data System (ADS)

The use of unmanned air vehicles to perform tactical operations is an increasing factor in battlefield strategy. Such systems can inexpensively satisfy a number of military missions in highly contested senarios without hazard to an aircrew. Computer controlled and piloted preplanned missions can be accomplished by autonomous air vehicles. However, such systems are lacking in flexibility to a degree that fails to respond to the fluidic processes of a modern battlefield. The incorporation of piloting capabilities to the unmanned air vehicles greatly increases their flexi-bility, enabling a wider range of mission capabilities, a higher success ratio and a greater survivability. New technological developments, taking advantage of quick response possibilities, allow of real time oper-ation under battlefield conditions. In future warfare, due to interdiction of operational airfields, unman-ned vehicles are likely to be the major source of the exercise of tactical air power. This paper discusses the piloting requirements for unmanned air vehicles as imposed by command and con-trol sequences, visual display, communications and the design and operation of remote control stations.

Clapp, Robert E.

1985-04-01

27

THE NRL MITE AIR VEHICLE  

Microsoft Academic Search

Micro Air Vehicles (MAVs) offer the promise of affordably expendable, covert sensor platforms for a range of close-in situational awareness activities. Since 1996, the US Naval Research Laboratory (NRL) has been developing technologies that will enable Navy-relevant missions with the smallest practical MAVs. This effort includes the development and integration of sensors, avionics, and advanced intelligent autopilots for flight control,

James Kellogg; Christopher Bovais; Jill Dahlburg; Richard Foch; John Gardner; Adam Sciambi; William Spears; Donald Srull; Carol Sullivan

2001-01-01

28

Oldenburg and Pan CO2 as Cushion Gas for CAES 1  

E-print Network

Oldenburg and Pan CO2 as Cushion Gas for CAES 1 CO2 as Cushion Gas for Compressed Air Energy of CAES is natural gas storage which is done in aquifers and depleted reservoirs. · Alternative cushion gas has been used in natural gas storage (specifically, N2). · Use of non-air cushion gas for CAES

Eisen, Michael

29

Cooperative Control for Autonomous Air Vehicles  

Microsoft Academic Search

The main objective of this research is to develop and evaluate the performance of strategies for cooperative control of autonomous\\u000a air vehicles that seek to gather information about a dynamic target environment, evade threats, and coordinate strikes against\\u000a targets. The air vehicles are equipped with sensors to view a limited region of the environment they are visiting, and are\\u000a able

Kevin Passino; Marios Polycarpou; David Jacques; Meir Pachter; Yang Liu; Yanli Yang; Matt Flint; Michael Baum

30

Piloting Of Unmanned Air Vehicles, II  

NASA Astrophysics Data System (ADS)

The use of unmanned air vehicles to perform tactical operations is an increasing factor in battlefield strategy. Such a system can inexpensively satisfy a number of military missions in highly contested scenarios without hazard to an aircrew. Computer controlled and piloted preplanned missions can be accomplished by autonomous air vehicles. However, such systems are lacking in flexibility to a degree that fails to respond to the fluidic processes of a modern battlefield. The incorporation of piloting capabilities to the unmanned air vehicles greatly increases their flexibility, enabling a wider range of mission capabilities, a higher success ratio and greater survivability. New technological developments, taking advantage of quick response possibilities, allow of real time operation under battlefield conditions. In future warfare, due to interdiction of operational airfields, unmanned vehicles are likely to the major source of the exercise of tactical air power. This paper discusses the piloting requirements for unmanned air vehicles as imposed by command and control sequences, visual display, communications and the design and operation of remote control stations. This paper is a continuation of SPIE paper 548-34 (Arlington, Va. , Apr 1985).

Clapp, Robert E.

1985-12-01

31

Air cushioned landing craft (LCAC) based ship to shore movement simulation: A decision aid for the amphibious commander. A (SMMAT) application  

NASA Astrophysics Data System (ADS)

Amphibious forces are the enabling force of choice to globally project rapid and sustainable combat power in the littoral. Whether delivering supplies and equipment for military operations or for humanitarian or disaster relief, the air cushioned landing craft (LCAC) is the primary surface ship-to-shore movement craft. The time needed to transfer the forces ashore may be critical to operational success and is an important planning consideration. Many factors complicate accurate prediction of this time. Even so, various commanders must use the best available information, given mission priorities and resource and capability limitations, to make numerous tradeoff decisions in planning and executing the movement of forces. A simulation toolbox, the simulated mobility modeling and analysis toolbox (SMMAT), is introduced, and a robust LCAC ship-to-shore simulation model is developed as an extension to SMMAT. This model provides the commander a prediction and tradeoff analysis tool for planning and executing the projection of power ashore.

Kearns, Edward P., III

1994-09-01

32

Aerodynamics for Revolutionary Air Vehicles  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

33

Flexible-Wing-Based Micro Air Vehicles  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

34

Membrane wing aerodynamics for micro air vehicles  

Microsoft Academic Search

The aerodynamic performance of a wing deteriorates considerably as the Reynolds number decreases from 106 to 104. In particular, flow separation can result in substantial change in effective airfoil shape and cause reduced aerodynamic performance. Lately, there has been growing interest in developing suitable techniques for sustained and robust flight of micro air vehicles (MAVs) with a wingspan of 15cm

Yongsheng Lian; Wei Shyy; Dragos Viieru; Baoning Zhang

2003-01-01

35

Micro air vehicle endurance versus battery size  

Microsoft Academic Search

Micro Air Vehicles (MAVs) operate with many inter-related constraints, including size, weight, power, processing, and communications bandwidth. Basic equations can be used to provide initial estimates of subsystem parameters that are consistent with the targeted size and related parameters. For most current MAVs, the power source of choice is batteries, and the choice of battery type and size will determine

Daniel W. Beekman

2010-01-01

36

Micro air vehicle. architecture and implementation  

Microsoft Academic Search

This paper presents the development of an electrically powered micro air vehicle (MAV) with a wingspan of 360 mm. A miniature flight control system including a self-made micro video image system especially suitable for MAV is developed. The aerodynamic performance of several airfoil sections at low chords Reynolds number is analyzed in order to find an optimum airfoil section for

Dong Sun; Zhao-ying Zhou I; Shen-shu Xiong; Xiao-hao Wang I

2003-01-01

37

ANINTEGERPROGRAMMINGMODELFORASSIGNING UNMANNED AIR VEHICLES TO TASKS  

E-print Network

the probability of destroying it, ii) deliberately utilizing a low-cost UAV as a decoy to induce an enemy radar of unmanned air vehicles (UAVs), deployed to carry out tasks such as searching for, classifying, attacking, and performing battle damage assessment of enemy targets. In some missions, it may be advantageous for the UAVs

Nygard, Kendall E.

38

Covert air vehicle 2003 LDRD final report.  

SciTech Connect

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.

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

2003-11-01

39

Ventilation control for improved cabin air quality and vehicle safety  

Microsoft Academic Search

Motor vehicles are a prime pollution source. In certain circumstances, the vehicle's exhaust may enter the vehicle cabin causing driver discomfort and adverse health effects. As a result, driver reflexes decrease and fatigue may be exhibited. Oxygen depletion due to vehicle occupant breathing can also threaten vehicle safety. Cabin air filters and ventilation control are capable of improving passenger comfort,

Kosmas Galatsis; W. Wlodarski; Yongxiang Li; K. Kalantar-zadeh

2001-01-01

40

Motor Vehicles, Air Pollution, and Climate Change  

NASA Astrophysics Data System (ADS)

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.

Mark, Jason

2000-04-01

41

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)

We report on the first systematic series of large-scale Pyroclastic Density Current (PDC) experiments using the New Zealand PDC Generator, a novel international research facility in Physical Volcanology recently commissioned at Massey University. Repeatable highly energetic and hot PDCs are synthesized by the controlled ';eruption column-collapse' of up to 3500 kg of homogenously aerated Taupo ignimbrite material from a 15 m-elevated hopper onto an instrumented inclined flume. At discharge rates between 250-1300 kg/s and low- to moderate gas injection rates (yielding initial solids concentration of 15-70 vol%) channelized gas-particle mixture flows life-scaled to dense PDCs can be generated. The flow fronts of the currents reach velocities of up to 9.5 m/s over their first 12 m of travel and rapidly develop strong vertical density stratification. The PDCs typically form a highly mobile, <60 cm-thick dense and channel-confined underflow, with an overriding dilute and turbulent ash cloud surge that also laterally escapes the flume boundaries. Depending on the PDC starting conditions underflows with 1-45 vol% solids concentration are formed, while the upper surge contains <<1 vol.% solids. A characteristic feature of the underflow is the occurrence of 'ignitive' front breakouts, producing jetted lobes that accelerate outward from the flow front, initially forming a lobe-cleft structure, followed by segregation downslope into multiple flow pulses. Depending on initial solids concentration and discharge rate, stratified, dune-bedded and inversely graded bedforms are created whose thicknesses are remarkably uniform along the medial to distal runout path characterising highly mobile flow runout. Along with high-speed video footage we present time-series data of basal arrays of load- and gas-pore pressure transducers to characterise the mobile dense underflows. Data shows that the PDCs are comprised of a turbulent coarse-grained and air-ingesting front with particle-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.

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

2013-12-01

42

Morphing Unmanned Air Vehicle Intelligent Shape and Flight Control  

E-print Network

the aircraft industry. Hong et al. develop an unmanned combat aerial vehicle that use shape changing to meetMorphing Unmanned Air Vehicle Intelligent Shape and Flight Control John Valasek , Amanda Lampton and demonstrates a complete methodology for the control of a morphing unmanned air vehicle. The shape learning

Valasek, John

43

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

NASA Astrophysics Data System (ADS)

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 ?s time resolution with a maximum detectable film thickness of approximately 8 ?m. This technique will be exploited in Part II to characterize the air film evolution during low velocity droplet impacts.

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

2015-01-01

44

Medium Altitude Endurance Unmanned Air Vehicle  

NASA Astrophysics Data System (ADS)

The medium altitude endurance unmanned air vehicle (MAE UAV) program (formerly the tactical endurance TE UAV) is a new effort initiated by the Department of Defense to develop a ground launched UAV that can fly out 500 miles, remain on station for 24 hours, and return. It will transmit high resolution optical, infrared, and synthetic aperture radar (SAR) images of well-defended target areas through satellite links. It will provide near-real-time, releasable, low cost/low risk surveillance, targeting and damage assessment complementary to that of satellites and manned aircraft. The paper describes specific objectives of the MAE UAV program (deliverables and schedule) and the program's unique position as one of several programs to streamline the acquisition process under the cognizance of the newly established Airborne Reconnaissance Office. I discuss the system requirements and operational concept and describe the technical capabilities and characteristics of the major subsystems (airframe, propulsion, navigation, sensors, communication links, ground station, etc.) in some detail.

Ernst, Larry L.

1994-10-01

45

Membrane wing aerodynamics for micro air vehicles  

NASA Astrophysics Data System (ADS)

The aerodynamic performance of a wing deteriorates considerably as the Reynolds number decreases from 10 6 to 10 4. In particular, flow separation can result in substantial change in effective airfoil shape and cause reduced aerodynamic performance. Lately, there has been growing interest in developing suitable techniques for sustained and robust flight of micro air vehicles (MAVs) with a wingspan of 15 cm or smaller, flight speed around 10 m/ s, and a corresponding Reynolds number of 10 4-10 5. This paper reviews the aerodynamics of membrane and corresponding rigid wings under the MAV flight conditions. The membrane wing is observed to yield desirable characteristics in delaying stall as well as adapting to the unsteady flight environment, which is intrinsic to the designated flight speed. Flow structures associated with the low Reynolds number and low aspect ratio wing, such as pressure distribution, separation bubble and tip vortex are reviewed. Structural dynamics in response to the surrounding flow field is presented to highlight the multiple time-scale phenomena. Based on the computational capabilities for treating moving boundary problems, wing shape optimization can be conducted in automated manners. To enhance the lift, the effect of endplates is evaluated. The proper orthogonal decomposition method is also discussed as an economic tool to describe the flow structure around a wing and to facilitate flow and vehicle control.

Lian, Yongsheng; Shyy, Wei; Viieru, Dragos; Zhang, Baoning

2003-10-01

46

75 FR 6338 - Protection of Stratospheric Ozone: New Substitute in the Motor Vehicle Air Conditioning Sector...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Substitute in the Motor Vehicle Air Conditioning Sector Under the Significant...for CFC-12 in motor vehicle air conditioning. The proposed substitute is...refrigerant for motor vehicle air conditioning, subject to use...

2010-02-09

47

Air-Conditioning for Electric Vehicles  

NASA Technical Reports Server (NTRS)

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.

Popinski, Z.

1984-01-01

48

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

49

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

50

Xebra Electric Vehicle ZAP stands for Zero Air Pollution.  

E-print Network

Page 1/7 CASE STUDY ZAP - USA Xebra Electric Vehicle #12;Page 2/7 ZAP stands for Zero Air Pollution, and cell-balanced battery pack. Normal driving lights were on and the indicator light was used when

51

AIR QUALITY IMPACTS OF ELECTRIC VEHICLE ADOPTION IN TEXAS  

E-print Network

conventional passenger cars in Texas, after recognizing the emissions and energy impacts of battery provisionAIR QUALITY IMPACTS OF ELECTRIC VEHICLE ADOPTION IN TEXAS Brice G. Nichols Associate Planner Puget adoption of plug-in electric vehicles (PEVs) may substantially reduce emissions of greenhouse gases while

Kockelman, Kara M.

52

Secure Firmware Updates over the Air in Intelligent Vehicles  

Microsoft Academic Search

Modern intelligent vehicles have electronic control units containing firmware that enables various functions in the vehicle. New firmware versions are constantly developed to remove bugs and improve functionality. Automobile manufacturers have traditionally performed firmware updates over cables but in the near future they are aiming at conducting firmware updates over the air, which would allow faster updates and improved safety

Dennis K. Nilsson; Ulf E. Larson

2008-01-01

53

Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings  

PubMed Central

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

Slegers, Nathan

2014-01-01

54

Design and analysis of a gyroscopically controlled micro air vehicle  

NASA Astrophysics Data System (ADS)

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.

Thorne, Christopher Everett

55

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

SciTech Connect

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.

Habors, D.T.; Hossain, M.

1998-09-01

56

Camber-adjustable flapping wing air vehicles  

Microsoft Academic Search

This paper introduces the implementation of adjustable camber of flapping wing and tail of a typical artificial flapping vehicle using a flexible piezoelectric actuator, called macro-fiber composites (MFC). When MFC is applied to the main wing of an ornithopter, the induced camber greatly affects aerodynamic characteristics such as mean lift and thrust. The tail wing actuation can be useful to

Jun-Seong Lee; Jae-Hung Han; Dae-Kwan Kim

2011-01-01

57

Effect of Intake Air Filter Condition on Vehicle Fuel Economy  

SciTech Connect

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

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

2009-02-01

58

Prototype air bag restraint for use in patrol vehicles  

SciTech Connect

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.

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

1995-03-01

59

Department of Mechanical Engineering Spring 2011 General Motors 2 Variable Height Vehicle Air Dam  

E-print Network

Vehicle Air Dam Overview The fundamental issue with fixed air dams is the bottom edge of the dam needs to be high enough to meet defined vehicle ground clearance and front approach angle criteria. Air dams must a solution to this problem by designing an variable height vehicle air dam. Objectives Our mission

Demirel, Melik C.

60

Air-Breathing Launch Vehicle Technology Being Developed  

NASA Technical Reports Server (NTRS)

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

Trefny, Charles J.

2003-01-01

61

Study of long term options for electric vehicle air conditioning  

SciTech Connect

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.

Dieckmann, J.; Mallory, D. (Little (Arthur D.), Inc., Cambridge, MA (United States))

1991-07-01

62

Study of long term options for electric vehicle air conditioning  

SciTech Connect

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.

Dieckmann, J.; Mallory, D. [Little (Arthur D.), Inc., Cambridge, MA (United States)

1991-07-01

63

Mechanically refuelable zinc/air electric vehicle cells  

NASA Astrophysics Data System (ADS)

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.

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

1992-12-01

64

Vector Field Path Following for Miniature Air Vehicles  

Microsoft Academic Search

In this paper, a method for accurate path following for miniature air vehicles is developed. The method is based on the notion of vector fields, which are used to generate desired course inputs to inner-loop attitude control laws. Vector field path following control laws are developed for straight-line paths and circular arcs and orbits. Lyapunov stability arguments are used to

Derek R. Nelson; D. Blake Barber; Timothy W. Mclain; Randal W. Beard

2007-01-01

65

Micro air vehicle: configuration, analysis, fabrication, and test  

Microsoft Academic Search

This paper presents the development of two electrically powered micro air vehicle (MAV) prototypes with wingspans of 380 and 360 mm, respectively. A miniature flight control system is constructed using small and light components. A vision system consisting of a micro radio frequency (RF) transmitter and a miniature vision-receiving antenna with a low-noise amplifier is designed, which exhibits advantages over

Huaiyu Wu; Dong Sun; Zhaoying Zhou

2004-01-01

66

An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles  

SciTech Connect

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.

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

2000-09-12

67

Adaptive path planning algorithm for cooperating unmanned air vehicles  

SciTech Connect

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.

Cunningham, C T; Roberts, R S

2001-02-08

68

Dioxin-receptor ligands in urban air and vehicle exhaust.  

PubMed Central

The ability of extracts of urban air and vehicle exhaust particulates to bind to the dioxin receptor has been determined. It was shown that such extracts do contain significant amounts of dioxin-receptor binding activity. The level of dioxin-receptor binding found in ambient air reflects its pollution level as determined by mutagenic activity. Furthermore, it was shown that the extracts of both urban air and vehicle exhaust particulates could provoke the induction of cytochrome P450IA1 in cultured rat hepatoma cells. Chemical fractionation of the extracts revealed that the majority of the dioxin-receptor binding activity from urban air and gasoline vehicle samples fractionated with the polycyclic aromatic compounds. However, unknown polycyclic aromatic compounds were responsible for the majority of the binding activity measured. In the case of diesel vehicle exhausts, the majority of the dioxin-receptor binding activity was found to be associated with nitro-polycyclic aromatic compounds. Studies with a variety of diesel fuels showed that the amount of dioxin-receptor ligands present in exhaust emissions are fuel-dependent and that substantial amounts of dioxin-receptor ligands are present in the semivolatile phase of exhaust emissions. PMID:7529698

Mason, G G

1994-01-01

69

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

SciTech Connect

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.

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

2001-08-28

70

A pressure control scheme for air brakes in commercial vehicles  

E-print Network

This research is focused on developing a control scheme for regulating the pressure in the brake chamber of an air brake system found in most commercial vehicles like trucks, tractor-trailers and buses. Such a control scheme can be used...

Bowlin, Christopher Leland

2007-04-25

71

Low-Observable Nonlinear Trajectory Generation for Unmanned Air Vehicles  

E-print Network

Keywords: Trajectory Generation, Path Planning, Low-Observable, UAV, RADAR, Probability of Detection Abstract This paper explores low observability flight path planning of unmanned air vehicles (UAV's) in the presence of radar detection systems. The probability of detection model of an aircraft near an enemy radar

Murray, Richard M.

72

Nonlinear trajectory generation for unmanned air vehicles with multiple radars  

Microsoft Academic Search

The problem of finding a real time optimal trajectory to minimize the probability of detection of unmanned air vehicles by opponent radar detection systems is investigated. This paper extends our preliminary results on low observable trajectory generation in three ways. First, trajectory planning in the presence of detection by multiple radar systems, rather than a single radar system, is considered.

Tamer Inanc; Kathy Misovec; Richard M. Murray

2004-01-01

73

Nonlinear Trajectory Generation for Unmanned Air Vehicles with Multiple Radars  

E-print Network

for constrained nonlinear optimization problems. Numerical simulations of multiple radar scenarios illustrate UAV Air Vehicles (UAVs) is radar detection systems. Designing optimal tra- jectories for UAV's which. In [18], we find low­observable trajectories for a UAV in the presence of a single radar without modeling

Murray, Richard M.

74

The real air quality benefits of gaseous-fueled vehicles.  

SciTech Connect

This paper provides a justification for prominent inclusion of currently available gaseous-fueled vehicles (i.e., vehicles powered by propane, sometimes called liquefied petroleum gas [LPG], or natural gas--chiefly, methane--stored onboard the vehicle in gaseous or liquid state but combusted as a gas) in the mix of strategies to (a) reduce public exposure to toxic and fine particulate emissions in the urbanized areas of the developing world and (b) achieve local and regional improvements in ozone air quality. It also presents estimates of associated emission reduction credits into the future. Important considerations discussed are the location of fine particle and toxic emissions in congested urban areas, and the location and timing of ozone precursor emissions, with emphasis on how gaseous-fueled vehicles' role in the relationship among and magnitude of these variables differs from that of their conventionally-fueled counterparts. Efforts to enhance the measurement and quantification of gaseous-fuel benefits are also described.

Saricks, C. L.

2002-03-28

75

Highway Crash Cushions  

E-print Network

. D. Sign Post E. Guardrail? Outside F. Guardrail? Inside 2. CAR STALLED ? HIT BY ANOTHER VEHICLE 10 16* 3. THROWN OR FELL OUT 4 ~ PEDESTRIAN 5 ~ WRONG-WAY COLL. 6. ACROSS MEDIAN ACCIDENT 12 12 7 ~ HIT RAIL ? STRUCK BY ANOTHER VEHICLE 8...- driver tests and 17 tests without a driver. The results of the two live-driver tests are presented at the end of this section. The results of the head-on hits are summari. zed in Table 10 whereas the side-angle tests are summarized in Table 11...

White, Monroe Carlton

2012-06-07

76

Analysis of Aeroelastic Flapping-Wing Signals for Micro Air-Vehicles.  

E-print Network

??Flapping-wing micro air-vehicles are being investigated for their potential to provide enhanced aerodynamic efficiency, maneuverability and gust tolerance. The flight dynamics of flapping-wing micro air-vehicles… (more)

Love, Robert

2009-01-01

77

61 FR 60635 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Air Compressor Cut-In  

Federal Register 2010, 2011, 2012, 2013, 2014

...automatic activation of the air compressor on a powered vehicle whenever...1996 final rule, the air compressor was required to automatically...balance between protection valve settings between the tractors...determined that the change in compressor cut-in pressure will...

1996-11-29

78

77 FR 1892 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Promulgation of Air Quality Implementation...removing the light duty vehicle...went into effect on January...ambient air quality standard...remove the light duty vehicle...went into effect on January...ambient air quality data from...2, the light duty vehicle...went into effect on...

2012-01-12

79

Multipurpose Uninhabited Air Vehicle (UAV) design and verification  

NASA Astrophysics Data System (ADS)

A multipurpose Uninhabited Air Vehicle was designed and built for the NASA University Research Center. It is capable of carrying a payload of up to 14 lbs with an estimated endurance of 3 hours. This thesis will describe the work that was completed on the aerodynamic and preliminary structural design of the air vehicle. It will be demonstrated how the size and configuration of the airframe were chosen based on the design requirements. The detailed design process will be described to achieve initial performance and mission requirements. Although the URC has successfully constructed airframes in the past, it is the intention of this thesis to also take a different approach on alternative construction methods in an effort to reduce cost and improve aircraft performance.

Barquero, Juan P.

80

Air liquefaction and enrichment system propulsion in reusable launch vehicles  

NASA Astrophysics Data System (ADS)

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.

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

1994-07-01

81

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

...proposed rule ``Control of Air Pollution from Motor Vehicles: Tier...emissions from passenger cars, light-duty trucks, medium- duty...important source of exposure to air pollution both regionally and near roads...fuel efficiency standards for light-duty vehicles, as part...

2013-04-08

82

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

Code of Federal Regulations, 2014 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL...Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty...1832-01 Optional equipment and air conditioning for test vehicles....

2014-07-01

83

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

Code of Federal Regulations, 2012 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL...Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty...1832-01 Optional equipment and air conditioning for test vehicles....

2012-07-01

84

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

Code of Federal Regulations, 2011 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL...Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty...1832-01 Optional equipment and air conditioning for test vehicles....

2011-07-01

85

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

Code of Federal Regulations, 2013 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL...Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty...1832-01 Optional equipment and air conditioning for test vehicles....

2013-07-01

86

Attachment device for an inflatable protective cushion  

DOEpatents

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.

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

1998-01-01

87

21 CFR 890.3175 - Flotation cushion.  

Code of Federal Regulations, 2011 CFR

...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a) Identification. A flotation...

2011-04-01

88

21 CFR 890.3175 - Flotation cushion.  

Code of Federal Regulations, 2010 CFR

...AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Prosthetic Devices § 890.3175 Flotation cushion. (a) Identification. A flotation...

2010-04-01

89

Conceptual design of flapping-wing micro air vehicles.  

PubMed

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

Whitney, J P; Wood, R J

2012-09-01

90

Avionics and control system development for mid-air rendezvous of two unmanned aerial vehicles  

E-print Network

A flight control system was developed to achieve mid-air rendezvous of two unmanned aerial vehicles (UAVs) as a part of the Parent Child Unmanned Aerial Vehicle (PCUAV) project at MIT and the Draper Laboratory. A lateral ...

Park, Sanghyuk, 1973-

2004-01-01

91

77 FR 3386 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Clean Vehicles Program  

Federal Register 2010, 2011, 2012, 2013, 2014

...Promulgation of Air Quality Implementation Plans; Pennsylvania; Clean Vehicles Program AGENCY: Environmental...revision submitted by the Commonwealth of Pennsylvania. This SIP revision contains Pennsylvania's Clean Vehicle Program, which...

2012-01-24

92

Electrospinning of a Micro-air Vehicle Wing Skin  

NASA Technical Reports Server (NTRS)

Electrospinning was utilized to create lightweight, electrically responsive wing skins for micro-air vehicle (MAV) wing frame designs. Various compositions of an electroactive polymer were investigated to determine the appropriate electrospinning conditions for these materials. Electrospun mats of these materials were characterized via optical microscopy and scanning electron microscopy. Tensile properties of the electrospun fibers were also measured. An optimal polymer composition was electrospun onto MAV wing frames to create a bird wing-like texture. Preliminary testing of electroactivity of these prototype MAV wings is reported here.

Pawlowski, K. J.; Belvin, H. L.; Raney, D. L.; Su, J.; Harrison, J. S.; Siochi, E. J.

2003-01-01

93

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

Federal Register 2010, 2011, 2012, 2013, 2014

...SNAP Rule for Motor Vehicle Air Conditioning Sector AGENCY: Environmental...ODSs) in the motor vehicle air conditioning end- use within the refrigeration and air conditioning sector, as acceptable...

2012-03-23

94

77 FR 17344 - Protection of Stratospheric Ozone: Amendment to HFO-1234yf SNAP Rule for Motor Vehicle Air...  

Federal Register 2010, 2011, 2012, 2013, 2014

...SNAP Rule for Motor Vehicle Air Conditioning Sector AGENCY: Environmental...ODSs) in the motor vehicle air conditioning end-use within the refrigeration and air conditioning sector, to be acceptable...

2012-03-26

95

Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles  

NASA Technical Reports Server (NTRS)

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.

Allen, Michael J.

2006-01-01

96

GPS Auto-Navigation Design for Unmanned Air Vehicles  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

97

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

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

98

Gas cushion control of OVJP print head position  

SciTech Connect

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.

Forrest, Stephen R

2014-10-07

99

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

SciTech Connect

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.

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

1980-04-01

100

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

NASA Technical Reports Server (NTRS)

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).

Ifju, Peter

2002-01-01

101

Optimal Trajectory Determination for Increased Relative Navigation Observability of Air Vehicles  

E-print Network

they Aerospace Engineer. Email: afrl.rvsv@kirtland.af.mil. Member AIAA. Professor, Department of Mechanical Adam M. Fosbury Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, NM

Crassidis, John L.

102

A novel zinc-air battery for electric vehicles  

SciTech Connect

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.

Ross, P.N. [Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

1995-07-01

103

Abstract--Unmanned Air Vehicles (UAVs) have several advantages and disadvantages compared with Unmanned  

E-print Network

at 30Hz. The pay- load attached to aircraft landing gear is shown in Figure 2. Unmanned Ground VehicleAbstract--Unmanned Air Vehicles (UAVs) have several advantages and disadvantages compared with Unmanned Ground Vehicles (UGVs). Both systems have different mobility and perception abilities. UAV systems

Florida, University of

104

Pioneer unmanned air vehicle accomplishments during Operation Desert Storm  

NASA Astrophysics Data System (ADS)

This paper will describe the accomplishments and lessons learned of the Pioneer Unmanned Air Vehicle (UAV) during Operations Desert Shield and Desert Storm. The Pioneer UAV has been deployed with three branches of the U.S. military (USA, USN, and USMC) for the past four years. Although the system has compiled over 6,000 flight hours, the recent conflict in the Gulf is the first opportunity to demonstrate its true value in a combat scenario. In a relatively short time (42 days), 307 flights and 1,011 flight hours were completed on Operation Desert Storm. This, coupled with the accuracy of various weapons systems that Pioneer observed/cued for, resulted in timely target engagements. This paper will chronicle the Pioneer deployment and accomplishments on Operations Desert Shield and Desert Storm. Various employment methods, tactics, doctrine, and lessons learned will be presented.

Christner, James H.

1991-12-01

105

Development and testing of an unmanned air vehicle telemetry system  

NASA Astrophysics Data System (ADS)

Unmanned air vehicles (UAV's) provide a low-cost, low-maintenance, and effective platform upon which experimentation can be performed to validate conceptual aerodynamic ideas. However, the UAV flight test data acquisition process is complex and requires a reliable recording system for post-flight data analysis. The thrust of this thesis was the development, construction, and validation of a viable telemetry system for data gathering and processing. Major areas of focus were: integration of the telemetry into a 1/8 scale model, radio controlled F-16A airplane; telemetry circuitry optimization; recording and display of instrumented parameters; and data reduction techniques necessary to obtain useful information. A flight test was flown and data was gathered using a steady-heading side-slip maneuver to demonstrate successful integration of all supporting elements.

Wilhelm, Kevin T.

1991-09-01

106

Attachment device for an inflatable protective cushion  

DOEpatents

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.

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

1998-12-08

107

Investigation of an energy harvesting small unmanned air vehicle  

NASA Astrophysics Data System (ADS)

The addition of energy harvesting is investigated to determine the benefits of its integration into a small unmanned air vehicle (UAV). Specifically, solar and piezoelectric energy harvesting techniques were selected and their basic functions analyzed. The initial investigation involved using a fundamental law of thermodynamics, entropy generation, to analyze the small UAV with and without energy harvesting. A notional mission was developed for the comparison that involved the aircraft performing a reconnaissance mission. The analysis showed that the UAV with energy harvesting generated less entropy. However, the UAV without energy harvesting outperformed the other UAV in total flight time at the target. The analysis further looked at future energy harvesting technologies and their effect on the energy harvesting UAV to conduct the mission. The results of the mission using the advanced solar technology showed that the effectiveness of the energy harvesting vehicle would increase. Designs for integrating energy harvesting into the small UAV system were also developed and tests were conducted to show how the energy harvesting designs would perform. It was demonstrated that the addition of the solar and piezoelectric devices would supply usable power for charging batteries and sensors and that it would be advantageous to implement them into a small UAV.

Magoteaux, Kyle C.; Sanders, Brian; Sodano, Henry A.

2008-03-01

108

Integration of an Autopilot for a Micro Air Vehicle  

NASA Technical Reports Server (NTRS)

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

Platanitis, George; Shkarayev, Sergey

2005-01-01

109

Suppressing Vertical Vibration in Railway Vehicles through Air Spring Damping Control  

Microsoft Academic Search

To improve the riding comfort of railway vehicles equipped with the air suspension system now in widespread use, we tested a semi-active air suspension control system with a variable orifice. The system is installed between the air spring and the auxiliary air chamber, and is adjusted using a controller with a design based on the H? control algorithm. We carried

Yoshiki Sugahara; Tadao Takigami; Akihito Kazato

2007-01-01

110

Q-Learning Approach to Automated Unmanned Air Vehicle (UAV) Demining  

E-print Network

Q-Learning Approach to Automated Unmanned Air Vehicle (UAV) Demining Silvia Ferrari and Greyson 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

Ferrari, Silvia

111

77 FR 75388 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Promulgation of Air Quality Implementation...by removing the light duty vehicle emission...that went into effect on January 1...national ambient air quality standard. (iv...by removing the light duty vehicle emission...that went into effect on January...

2012-12-20

112

An analytical comparison of adsorption and vapor compression air conditioners for electric vehicle applications  

Microsoft Academic Search

This paper shows an analysis of the applicability of an adsorption system for electric vehicle (EV) air conditioning. Adsorption systems are designed and optimized to provide the required cooling for four combinations of vehicle characteristics and driving cycles. The resulting adsorption systems are compared with vapor compression air conditioners that can satisfy the cooling load. The objective function is the

S. M. Aceves

1996-01-01

113

Improvement of Passengers Ride Comfort in Rail Vehicles Equipped with Air Springs  

Microsoft Academic Search

In rail vehicles, air springs are very important isolating component, which guarantee good ride comfort for passengers during their trip. In the most new rail-vehicle models, developed by researchers, the thermo-dynamical effects of air springs are ignored and secondary suspension is modeled by simple springs and dampers. As the performance of suspension components have significant effects on rail-vehicle dynamics and

H. Sayyaadi; N. Shokouhi

2009-01-01

114

77 FR 73459 - California State Motor Vehicle Pollution Control Standards; Notice of Waiver of Clean Air Act...  

Federal Register 2010, 2011, 2012, 2013, 2014

...PROTECTION AGENCY [FRL-9759-4] California State Motor Vehicle Pollution Control...Waiver of Clean Air Act Preemption; California's 2010 Model Year Heavy-Duty Vehicle...SUMMARY: EPA has granted the California Air Resources Board (CARB) its...

2012-12-10

115

Air Quality Impacts of Some Alternative Vehicle Options UC Irvine National Fuel Cell Research Center 1 March 28, 2008  

E-print Network

Air Quality Impacts of Some Alternative Vehicle Options UC Irvine National Fuel Cell Research of California, Irvine (UCI) #12;Air Quality Impacts of Some Alternative Vehicle Options UC Irvine National Fuel.......................................................................................................... 37 #12;Air Quality Impacts of Some Alternative Vehicle Options UC Irvine National Fuel Cell Research

Dabdub, Donald

116

BLDC motor drive system of air-condition of hybrid electric vehicle  

Microsoft Academic Search

Recently the research and development of electric compressor in the electric automobile have being focused on. In HEV (hybrid electric vehicle), the engine is turned off in the case of stop to raise fuel efficiency and prevent air pollution. The conventional air conditioner system which is worked by the engine power through belt connection can't provide cool air to inside

Tae Uk Jung; Sung Ho Lee; Sung Jun Park; Cheol Ho Yun; Yu Tao

2007-01-01

117

Aerial networking communication solutions using Micro Air Vehicle (MAV)  

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

118

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

NASA Technical Reports Server (NTRS)

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

Wood, Richard M.

2002-01-01

119

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

120

Membrane and adaptively-shaped wings for micro air vehicles  

NASA Astrophysics Data System (ADS)

Micro air vehicles (MAVs), with wing span of 15 cm or less and flight speed around 10 m/s, have many applications in both civilian and military areas. The Reynolds number based on the given parameters is around 10 4, which often yields insufficient lift-to-drag ratio. Furthermore, one expects the unsteady effect to be noticeable for such flight vehicles. The flexible wing has been demonstrated to exhibit favorable characteristics such as passive adaptation to the flight; environment and delayed stall. The present study focuses on developing computational and modeling capabilities to better understand the MAV aerodynamics. Both flexible wings, utilizing membrane materials, and adaptively-shaped wings, utilizing piezo-actuated flaps, have been studied. In the adaptively-shaped wing study, we use piezo-actuated flaps to actively control the flow. We assess the impacts of the flap geometry, flapping amplitude, and turbulence; modeling on the flow structure with a parallel experimental effort. The membrane wing uses a passive control mechanism to delay the stall angle and to provide a smoother flight platform. Our study focuses on the mutual interactions between the membrane wing and its surrounding viscous flow. We compare the lift-to-drag ratio and the flow structure between the flexible wing and the corresponding rigid wing. We also investigate the aerodynamic characteristics associated with the low Reynolds number and low aspect ratio wing. To assist our study, we propose an automatic and efficient moving grid technique to facilitate the fluid and structure interaction computations; we also present a dynamic membrane model to study the intrinsic large deformation of the flexible membrane wing. Solutions obtained from the three-dimensional Navier-Stokes equations are presented to highlight, the salient features of the wing aerodynamics. Besides the aerodynamic study, we also perform shape optimization to improve the membrane wing performance. Since direct optimization of a membrane wing is too time consuming to be practical, we optimize a surrogate rigid wing model based on an integrated optimization algorithm, which consists of a Navier-Stokes solver, an automatic grid generation tool; and a gradient-based optimizer. Then, we assess the membrane wing performance based on the outcome from the surrogate model. Our numerical results confirm that the membrane wing exhibits consistent improvement in the lift-to-drag ratio with the surrogate model.

Lian, Yongsheng

121

Co-ordinated Tracking and Planning Using Air and Ground Vehicles  

E-print Network

The MAV ’08 competition in Agra, India focused on the problem of using air and ground vehicles to locate and rescue hostages being held in a remote building. Executing this mission required addressing a number of technical ...

Bachrach, Abraham Galton

122

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

123

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

124

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

125

Unmanned air vehicle (UAV) ultra-persitence research  

SciTech Connect

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

Dron, S. B.

2012-03-01

126

A Selfish Approach to Coalition Formation among Unmanned Air Vehicles in Wireless Networks  

E-print Network

A Selfish Approach to Coalition Formation among Unmanned Air Vehicles in Wireless Networks Walid aerial vehicles (UAVs) have a great potential for deployment in next generation wireless networks. While in military ad hoc networks, this paper proposes a novel usage model for UAVs in wireless communication

Boyer, Edmond

127

Coupled Vehicle Design and Network Flow Optimization for Air Transportation Systems  

E-print Network

Coupled Vehicle Design and Network Flow Optimization for Air Transportation Systems Christine: 10.2514/1.27320 Traditionally, the design of a transportation system has focused on either vehicle for a transportation system, it is advantageous to expand the system boundary during the design process to include

de Weck, Olivier L.

128

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

PubMed

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. PMID:22619934

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

2011-08-01

129

Vision-Based Control of MicroAirVehicles: Progress and Problems In Estimation  

E-print Network

Vision-Based Control of Micro­Air­Vehicles: Progress and Problems In Estimation A. Kurdila, M, Columbia, SC 29208 Abstract-- Vision-based control of agile autonomous vehicles in complicated 3-D. These disciplines include control theory, vision processing, signal processing, sensor development, micro

DeVore, Ronald

130

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

131

Ambient particulate air pollution from vehicles promotes lipid peroxidation and inflammatory responses in rat lung  

Microsoft Academic Search

Oxidative stress plays a major role in the pathogenesis of particle- dependent lung injury. Ambient particle levels from vehicles have not been previously shown to cause oxidative stress to the lungs. The present study was conducted to a) determine whether short-term exposure to ambient levels of particulate air pollution from vehicles elicits inflammatory responses and lipid peroxidation in rat lungs,

C. E. L. Pereira; T. G. Heck; P. H. N. Saldiva; C. R. Rhoden

2007-01-01

132

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

Code of Federal Regulations, 2010 CFR

...Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1832-01 Optional equipment...available to the Agency upon request by the Administrator within 15 business days. (c) Except for air conditioning, where it...

2010-07-01

133

Vibration testing of off-road vehicle seats  

SciTech Connect

The US Bureau of Mines, in cooperation with Carter Mining Co., conducted vibration tests of four off-road vehicle seats. The purpose of the tests was to determine which seat provides the best vibration attenuation under laboratory conditions. Laboratory tests were constructed to simulate the mining vibration environment within the limitations of the test equipment. The acceleration test levels and corresponding response of the seats were low compared to ISO 2631's fatigue-decreased-proficiency time limits. Two of the seats employed mechanical suspensions and two seat employed air suspensions. The seats were tested using a 22,241-N (5,000-IBF) electrodynamic shaker. Mechanical suspension seats were tested with various preload-to-mass ratios (PMR's) and cushion densities. Air suspension seats were tested with various air pressure levels and seat cushion densities. Air suspension seats provides good vibration attenuation if pressurized greater than 552 kPa psi. Mechanical suspension seats attenuation performance decreases if the PMR exceeded 9.8. Seat cushions of lower density provides less vibration damping.

Gagliardi, J.C.; Utt, W.K.

1993-01-01

134

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

NASA Astrophysics Data System (ADS)

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

Christensen, Kirk Le

135

The promise of air cargo: System aspects and vehicle design  

NASA Technical Reports Server (NTRS)

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.

Whitehead, A. H., Jr.

1976-01-01

136

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

Microsoft Academic Search

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

Elizabeth A. Garthe; Nicholas K. Mango; Brad Prenney

2000-01-01

137

Numerical simulation of engine cooling air flow of a road vehicle  

Microsoft Academic Search

A modeling method for a heat exchanger is presented to predict engine cooling air flow rate. The comparison between calculations and experiments confirms accuracy of the modeling method. A modeling of vehicle body configuration is also discussed. It is found that precise modeling of engine room outlet configuration is important to improve estimation accuracy of engine cooling air flow rate.

Tetsuji Ukita; Takuya Kataoka; Hiroshi China

1993-01-01

138

75 FR 39251 - Control of Air Pollution From New Motor Vehicles: Announcement of Public Workshop for Heavy-Duty...  

Federal Register 2010, 2011, 2012, 2013, 2014

...ENVIRONMENTAL PROTECTION AGENCY [FRL-9173-5] Control of Air Pollution From New Motor Vehicles: Announcement of Public Workshop for...1\\ See ``Certification Procedure for Light-Duty and Heavy-Duty Diesel Vehicles and Heavy-Duty...

2010-07-08

139

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

SciTech Connect

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.

Rugh, J. P.

2010-04-01

140

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

141

California's Zero Emission Vehicle Program Cleaner air needed  

E-print Network

Stage 1 smog alerts each year in the Los Angeles area. Major efforts to reduce air pollution, mainly smog alerts in Los Angeles never exceeded 14 in one year. There were no Stage 1 alerts in 1999 or 2000 that fail to meet federal or state air quality standards. ? Roughly 50% of smog-forming pollutants still

Gille, Sarah T.

142

Towards energy efficiency in micro hovering air vehicles  

Microsoft Academic Search

Micro Aerial Vehicles (MAVs) have gained a sig- nificant amount of research lately, with a number of uni- versities and industry sponsors paving the way with micro flying robots to perform Intelligence, Surveillance and Re- connaissance (ISR) Missions. However, much of the work done in VTOL\\/Hover-Capable MAVs till date has not shown performance improvement in flight endurance and payload capacities.

Jayant Ratti; George Vachtsevanos

2011-01-01

143

Radar-based detection and identification for miniature air vehicles  

Microsoft Academic Search

It is claimed that Unmanned Aerial Vehicles (UAVs) used for civilian\\/publicdomain applications will be dom- inant in the near future. Compared to UAVs used by the mili- tary, civilian UAVs are often operated by pilots without formal training, and hence they require increased levels of autonomy and intelligence, especially with regard to reducing threats to public safety. UAV integration into

Allistair Moses; Matthew J. Rutherford; Kimon P. Valavanis

2011-01-01

144

Adaptive Neuro-Fuzzy Inference System Based Autonomous Flight Control of Unmanned Air Vehicles  

Microsoft Academic Search

This paper proposes ANFIS logic based autonomous flight controller for UAVs (unmanned aerial vehicles). Three fuzzy logic\\u000a modules are developed for the control of the altitude, the speed, and the roll angle, through which the altitude and the latitude-longitude\\u000a of the air vehicle is controlled. The implementation framework utilizes MATLAB’s standard configuration and the Aerosim Aeronautical\\u000a Simulation Block Set which

Sefer Kurnaz; Okyay Kaynak; Ekrem Konakoglu

2007-01-01

145

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

SciTech Connect

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.

NONE

1995-03-01

146

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

NASA Astrophysics Data System (ADS)

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.

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

2008-04-01

147

Relative Navigation of Air Vehicles Adam M. Fosbury  

E-print Network

. Most applications Aerospace Engineer. Email: afrl.rvsv@kirtland.af.mil. Member AIAA. Professor Directorate, Kirtland Air Force Base, NM 87117 John L. Crassidis University at Buffalo, State University

Crassidis, John L.

148

Fire resistant resilient foams. [for seat cushions  

NASA Technical Reports Server (NTRS)

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.

Gagliani, J.

1976-01-01

149

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)

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.

Hall, David W.

2001-01-01

150

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

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

151

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

NASA Astrophysics Data System (ADS)

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 not as significant as the increase in the current density away from the entrance. By extending the cathode below the anode, the high local current density can be reduced.

Yang, Shaohua

152

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

Microsoft Academic Search

In recent years, air-spring-type tilting vehicles, which use air springs as the car-body tilt mechanism, have been employed, even in Shinkansen trains, to increase the operation speed on curved sections. On a test train running at a speed of about 300 km\\/h with the tilt mechanism, however, it was found that the car-body roll and lateral vibrations increased in compound

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

2009-01-01

153

Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle  

NASA Technical Reports Server (NTRS)

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.

Allen, Michael J.

2005-01-01

154

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

NASA Astrophysics Data System (ADS)

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.

Yang, Shaohua; Knickle, Harold

155

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

NASA Technical Reports Server (NTRS)

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.

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

156

Wireless Video Noise Classification for Micro Air Vehicles  

Microsoft Academic Search

Onboard processing of video is currently outside the capabilities of power limited micro air vehi- cles (MAVs), which forces researchers to transmit video and telemetry to a ground control station for capture and offline processing. Unfortunately, wireless video transmission can introduce struc- tured noise, which can corrupt image processing algorithms if the noisy frames are not identified and rejected from

Jeffrey Byrne; Raman Mehra

157

Design of an air sampler for a small unmanned aerial vehicle.  

PubMed

In the aftermath of a nuclear accident or malevolent act, it is of paramount importance to have the capability to monitor airborne radioactive substances by collecting air samples. For potentially dangerous missions, the Radiation and Nuclear Safety Authority of Finland (STUK) has developed an air sampler to be used on a small unmanned aerial vehicle. When a Petrianov or Fluoropore filter is used in the sampler and the air velocity is 71 km h(-1), the air flow rate through the filter is 0.73 m(3) h(-1) or 0.23 m(3) h(-1), respectively. The present article introduces the developed air sampler using fluid dynamic simulations and wind tunnel data. The operation of the system was validated by collecting airborne radioactive aerosols from air. PMID:19091809

Peräjärvi, K; Lehtinen, J; Pöllänen, R; Toivonen, H

2008-01-01

158

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

NASA Astrophysics Data System (ADS)

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

Rege, Alok Ashok

159

AIAA 2004-6598 FLOW SIMULATION AROUND A MICRO AIR VEHICLE  

E-print Network

, when the smallest air- planes in use were the Uninhibited Aerial Vehicles (UAVs) with a wingspan a 1 cm wingspan ve- hicle that can carry a 1 gram payload [1]. It is clear that this goal has not been; in most cases the chord is roughly equal to the wingspan. This com- bination of low Reynolds number flight

Mohseni, Kamran

160

FLOW SEPARATION WITHIN THE ENGINE INLET OF AN UNINHABITED COMBAT AIR VEHICLE (UCAV)  

Microsoft Academic Search

This paper discusses the structure of the flow within the engine inlet of an uninhabited combat air vehicle (UCAV). The UCAV features a top-mounted, serpentine inlet leading to an engine buried within the fuselage. The performance of the inlet is found to depend strongly on a flow separation that occurs within the inlet. Both the time-averaged and the unsteady structure

Michael J. Brear; Zachary Warfield; John F. Mangus; Steve Braddom; James D. Paduano; Jeffry S. Philhower

2003-01-01

161

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...

162

Radar Cross Section measurements of small Unmanned Air Vehicle Systems in non-cooperative field environments  

Microsoft Academic Search

The growing use of unmanned air vehicle systems (UAVS) is drawing increased interest in their radar signature to search and track radars. Because it is not always possible to transport UAVS to radar cross section (RCS) measurement facilities, a portable RCS measurement system has been developed and demonstrated in non-cooperative field environments. This paper presents the portable RCS measurement system

A. Bati; D. Hilliard

2009-01-01

163

Seacoaster advanced marine vehicle. Final report  

SciTech Connect

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

Burg, D.

1998-08-18

164

Optimal design for hybrid rocket engine for air launch vehicle  

Microsoft Academic Search

A feasibility study and the optimal design was conducted for the application of a hybrid motor with HTPB\\/LOX combination to\\u000a the first stage of an air launch system. The feasibility analysis showed that the hybrid motor could successfully be used\\u000a as a substitute for the solid rocket motor of the first stage of the Pegasus XL if the average specific

Ihnseok Rhee; Changjin Lee; Jae-Woo Lee

2008-01-01

165

60 FR 31135 - Federal Motor Vehicle Safety Standards; Air Brake Systems Air Compressor Cut-In  

Federal Register 2010, 2011, 2012, 2013, 2014

...building tractors whose nominal compressor cut-in pressure is at least...increasing the minimum air compressor cut-in pressure requirement...match up'' of protection valve settings between the tractors...governors that activate the air compressor when air pressure drops...

1995-06-13

166

61 FR 6173 - Federal Motor Vehicle Safety Standards; Air Brake Systems; Air Compressor Cut-In  

Federal Register 2010, 2011, 2012, 2013, 2014

...required minimum air compressor cut-in pressure from...up'' of protection valve settings between the...activation of the air compressor whenever the pressure...up'' of protection valve settings between the...decided to apply the air compressor cut-in pressure...

1996-02-16

167

Fire blocking systems for aircraft seat cushions  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

168

Segmented tubular cushion springs and spring assembly  

NASA Technical Reports Server (NTRS)

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).

Haslim, Leonard A. (Inventor)

1988-01-01

169

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

PubMed

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. PMID:11184482

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

2000-01-01

170

3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Vehicle Conference and Flight Competition (EMAV2007), 17-21 September 2007, Toulouse, France  

E-print Network

3rd US-European Competition and Workshop on Micro Air Vehicle Systems (MAV07) & European Micro Air Mission Planning for a Fleet of Micro Air Vehicules Pierre-Selim Huard and Nicolas Barnier ´Ecole: the manual level, the augmented stability level with or without pilot through video, the flight plan level

Paris-Sud XI, Université de

171

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

PubMed

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

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

2009-12-01

172

Thermal Performance of Aircraft Polyurethane Seat Cushions  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

173

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

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

174

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

SciTech Connect

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.

Jacobson, M.Z.; Colella, W.G.; Golden, D.M. [Stanford University, Stanford, CA (US). Dept. of Civil & Environmental Engineering

2005-06-24

175

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

PubMed

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

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

2005-06-24

176

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

NASA Astrophysics Data System (ADS)

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.

Cooper, J. F.

1980-01-01

177

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

PubMed

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

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

2014-08-15

178

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

PubMed Central

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

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

2014-01-01

179

Concurrent trajectory and conceptual vehicle design optimization of an aerobatic air race aircraft  

NASA Astrophysics Data System (ADS)

This paper deals with the development of a framework for the concurrent optimization of trajectory and conceptual vehicle design. The tool is applied to the design of an aerobatic air race aircraft that is required to fly a prescribed slalom course consisting of inflatable pylons in the fastest possible time. It is shown that when the aircraft design is tailored to the characteristics of the race track, an improvement in the lap time of about 1 percent can be achieved.

Visser, Hendrikus G.; Liem, Christiaan

2014-10-01

180

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

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

181

Hover and wind-tunnel testing of shrouded rotors for improved micro air vehicle design  

Microsoft Academic Search

The shrouded-rotor configuration has emerged as the most popular choice for rotary-wing Micro Air Vehicles (MAVs), because of the inherent safety of the design and the potential for significant performance improvements. However, traditional design philosophies based on experience with large-scale ducted propellers may not apply to the low-Reynolds-number (˜20,000) regime in which MAVs operate. An experimental investigation of the effects

Jason L. Pereira

2008-01-01

182

Measurement and modelling of the y-direction apparent mass of sitting human body–cushioned seat system  

Microsoft Academic Search

Laboratory tests were conducted using 13 male subjects seated on a cushioned commercial vehicle driver's seat. The hands gripped a mock-up steering wheel and the subjects were in contact with the lumbar region of the backrest. The accelerations and forces in the y-direction were measured during random lateral whole-body vibration with a frequency range between 0.25 and 30Hz, vibration magnitudes

George Juraj Stein; Peter Múcka; Barbara Hinz; Ralph Blüthner

2009-01-01

183

AirCRED : the rationale and structure of a tool for estimating air pollutant reduction credits for alternative fuel vehicles.  

SciTech Connect

Primarily to assist the U.S. Department of Energy's Clean Cities coalitions in estimating the net benefits of reducing air pollutant emissions gained by acquiring original equipment manufacture (OEM) alternativefuel vehicles (AFVs), Argonne National Laboratory has developed a graphical user interface-based benefit calculation model called AirCred. The application of this modeling tool has been extended to the estimation of state implementation plan credits for AFVs that may be claimed in nonattainment and maintenance regions for ozone and carbon monoxide. The tool also has been approved for and applied to the quantification of projected program benefits in applications for grant support to purchase OEM AFVs under the U.S. Department of Transportation's Congestion Mitigation and Air Quality Program. First, the model's founding principles and relatively simple mechanics are presented, accompanied by graphic displays of data input screens and comparative results for various vehicular categories. Current and future plans are cited for enhancement of the tool, including its respecification for consistency with MOBILE6 and for air planning in the yet-to-be-designated nonattainment areas for ambient particulate matter of 2.5 {mu}m and smaller. Then some issues and controversies about how and where AirCred should be applied are chronicled. Finally, some example applications are presented to illustrate the residual benefits of AFVs over time relative to their conventionally fueled counterparts of the same (recent) model year. Results indicate that AFVs of certain categories will remain viable and attractive candidates for reducing air emissions in ozone and carbon monoxide air quality control regions well into the future.

Saricks, C. L.; Energy Systems

2002-01-01

184

Adjusting stiffness of air spring and damping of oil damper using fuzzy controller for vehicle seat vibration isolation  

Microsoft Academic Search

In this paper we present one of the concepts of vehicle seat vibration damping, using a fuzzy controller. We used a fuzzy controller as a part of a semi-active vehicle suspension system, which consists of semi-active air spring and semi-active damper. System is implemented between the cabin floor and vehicle seat. Fuzzy controller is designed to adjust the stiffness of

Senad Huseinbegovic; Omer Tanovic

2009-01-01

185

Radar-Based Detection and Identification for Miniature Air Vehicles Allistair Moses, Matthew J. Rutherford, Kimon P. Valavanis  

E-print Network

Radar-Based Detection and Identification for Miniature Air Vehicles Allistair Moses, Matthew J. Rutherford, Kimon P. Valavanis Abstract-- It is claimed that Unmanned Aerial Vehicles (UAVs) used for civilian/public domain applications will be dom- inant in the near future. Compared to UAVs used

Minnesota, University of

186

Cushion system for multi-use child safety seat  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

187

Cushion System for Multi-Use Child Safety Seat  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

188

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

NASA Technical Reports Server (NTRS)

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

1963-01-01

189

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

PubMed

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

Wadud, Zia; Khan, Tanzila

2013-12-17

190

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

PubMed

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

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

2015-01-01

191

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

NASA Astrophysics Data System (ADS)

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.

Dalle, Derek J.

192

Design of composite plastic foams for improved cushioning  

E-print Network

the shipping environment. Shock and vibration ? ASTM D4169 2) Assess product fragility. Shock ? ASTM D3332 Vibration ? ASTM D3580 3) Redesign product (if required to improve fragili- ty). 4) Evaluate cushion material. Shock (slab materials) ? ASTM D1596...

Eskew, James Oliver

2012-06-07

193

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

NASA Astrophysics Data System (ADS)

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

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

2009-09-01

194

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

PubMed

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

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

2015-01-01

195

Dynamic modelling of servo pneumatic actuators with cushioning  

Microsoft Academic Search

Precise modelling of servo-pneumatic actuation plants continues to remain a major challenge. In this work, the complete mathematical\\u000a model of a double-acting pneumatic cylinder with cushioning sections at both ends of the piston stroke has been developed.\\u000a The proposed model considers the entire stroke of the piston, including cushioning sections as these sections affect the positioning\\u000a accuracy of the piston.

Farid Najafi; Morteza Fathi; Mozafar Saadat

2009-01-01

196

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...

197

International Micro Air Vehicle Conference and Flight Competition (IMAV2013) 17-20 September 2013, Toulouse, France  

E-print Network

International Micro Air Vehicle Conference and Flight Competition (IMAV2013) 17-20 September 2013 parameters used for both configurations such as wing surface area, cruise speed, battery capacity, different-board battery energy found interactively by a post-filtering program developed in-house. A custom air- foil

Boyer, Edmond

198

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

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

199

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

NASA Technical Reports Server (NTRS)

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

Roche, Joseph M.; Kosareo, Daniel N.

2001-01-01

200

Electric vehicles  

Microsoft Academic Search

The renewed interest in electric vehicles (EVs) in the wake of the California Air Resources Board mandate that 2% of the vehicles lighter than 3750 lb (1700 kg) sold by each manufacturer in that state in 1998 be zero-emission vehicles is examined. The reasons why replacing an internal combustion vehicle (ICV) with an electrically powered equivalent greatly reduces air pollution,

M. J. Riezenman

1992-01-01

201

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

202

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

203

Thermal performance of aircraft polyurethane seat cushions  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

204

Formation of photochemical air pollution in central California 1. Development of a revised motor vehicle emission inventory  

NASA Astrophysics Data System (ADS)

Photochemical air pollution problems have proved difficult to understand and control in central California. A major source of uncertainty is the rate of precursor volatile organic compounds and NOx emissions, especially from motor vehicles. We develop alternative emissions estimates for on-road motor vehicles in 1990, using fuel sales data, emission factors measured in on-road studies, and ambient pollutant ratios, for a region that includes the San Francisco Bay and San Joaquin Valley air basins and Sacramento County. Fuel-based emissions estimates are compared with predictions of California's most recent motor vehicle emission factor model (EMFAC) and with an inventory that has been used in previous regional-scale photochemical modeling studies. The fuel-based inventory contains 10-50% less CO, 40-100% more nonmethane organic compounds, and 10-20% less NOx than estimated both by EMFAC and the photochemical modeling inventory. We also describe new temporal distributions of vehicle emissions by hour and day of week. Diesel trucks, a major source of NOx, have a broad midday peak in emissions on weekdays, in contrast to passenger vehicles, which show morning and afternoon commuter peaks. While passenger vehicle travel is similar on weekdays and weekends, diesel truck activity and emissions decrease by 70-80% on weekends. Vehicle emission rates and their temporal patterns are linked to a regional photochemical air pollution episode that spans a weekend in August 1990.

Marr, Linsey C.; Black, Douglas R.; Harley, Robert A.

2002-03-01

205

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

NASA Astrophysics Data System (ADS)

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.

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

206

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

PubMed

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. PMID:17310696

Mazzi, Eric A; Dowlatabadi, Hadi

2007-01-15

207

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

208

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

DOEpatents

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.

Farrington, Robert B. (Golden, CO); Anderson, Ren (Broomfield, CO)

2001-01-01

209

Effect of Connecting the Front and Rear Air Suspensions of a Vehicle on the Transmissibility of Road Undulation Inputs  

Microsoft Academic Search

Airsprings have been used for vehicle suspensions over the last 40 years. They are mostly used as independent suspensions. Analysis of air springs available in literature is mostly limited to a single-degree-of-freedom system or a two-degrees-of-freedom system only in the translation mode. This paper deals with a model of a vehicle where the front and the rear springs are connected

S. Y. BHAVE

1992-01-01

210

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

NASA Technical Reports Server (NTRS)

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.

Midea, Anthony C.

1991-01-01

211

Mach 6.5 air induction system design for the Beta II Two-Stage-to-Orbit booster vehicle  

NASA Technical Reports Server (NTRS)

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.

Midea, Anthony C.

1991-01-01

212

76 FR 55859 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems  

Federal Register 2010, 2011, 2012, 2013, 2014

...Federal Motor Vehicle Safety Standard...newly-manufactured vehicles equipped with...agency require a driver-controllable...increase in two-vehicle rear end crashes...the striking vehicle. However, this...mph, allowing drivers to disable the...altogether on heavy vehicles. The...

2011-09-09

213

Vibration Effects Examination of Cushions Used on Tractor Driving Seat  

NASA Astrophysics Data System (ADS)

Vibration effect of driver’s seat of agricultural tractor which works in land condition has been researched. In this research, three dif- ferent cushions on driver’s seat have been used. These are wool, sponge and cotton. Pad acceleration receiver is put on seat. Moreover, HVM100 tool has been used to record data. Data has been converted to graphs in BLAZE software. Statistical methods have been used in examining the graphs. In vibration isolation, ordering has been achieved as wool, cotton and sponge and without a cushion, respectively. Wool cushion has the best isolation. It is seen that data obtained from test results is appropri- ate according to ISO 2631 standards and scientific researches.

Marul, Musa; Karabulut, Abdurrahman

2012-12-01

214

A model to assess the comfort of automotive seat cushions.  

PubMed

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

Jiaxing, Zhan; Fard, Mohammad; Jazar, Reza

2014-01-01

215

Expression and function of bone morphogenetic proteins in the development of the embryonic endocardial cushions  

Microsoft Academic Search

Bone morphogenetic proteins (BMPs) are considered to be significant factors in the morphogenesis of the endocardial cushions of the developing embryonic heart. Previous studies have suggested that they are involved in the epithelial–mesenchymal transformation and migration of the cells forming the cushions, or in triggering an apoptotic cascade in a sub-population of cushion cells. We investigated the expression and function

William M. Keyes; Cairine Logan; Eve Parker; Esmond J. Sanders

2003-01-01

216

Low-emission vehicle adoption in a UK local authority fleet: economic barriers and air quality benefits  

Microsoft Academic Search

Local air quality was one of the main stimulants for low carbon vehicle development during the 1990s. Issues of national fuel security and global air quality (climate change) have added pressure for their development, stimulating schemes to facilitate their deployment in the UK. In this case study, Coventry City Council aimed to adopt an in-house fleet of electric and hybrid-electric

Samantha Cruickshank; Michaela Kendall

2011-01-01

217

NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept  

NASA Technical Reports Server (NTRS)

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.

Nguyen, Nhan

2010-01-01

218

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

NASA Astrophysics Data System (ADS)

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

Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

219

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

PubMed

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

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

2011-12-01

220

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

NASA Astrophysics Data System (ADS)

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

Kress, Gregory A.

1992-09-01

221

An adsorption air conditioning system to integrate with the recent development of emission control for heavy-duty vehicles  

Microsoft Academic Search

The recent development to control the emissions of large diesel engines has provided opportunities for heat-driven cooling methods in vehicles. An adsorption air conditioning system is therefore proposed in this work for heavy-duty truck application. This system is powered by engine waste heat when the engine of a truck is running. When the engine is off, it can be operated

Yongfang Zhong; Tiegang Fang; Kevin L. Wert

2011-01-01

222

Highly efficient brushless motor design for an air-conditioner of the next generation 42 V vehicle  

Microsoft Academic Search

In the past few years, worldwide awareness of environmental problems has grown dramatically. The idling stop and 42 V battery system has attracted large attention for next generation vehicle. In order to adapt to idling stop, air-conditioning compressors are required to be changed to electric-motor driven from gasoline engine driven. This paper discusses the optimum design of a high speed

Hiroshi Murakami; Hisakazu Kataoka; Yukio Honda; Shigeo Morimoto; Yoji Takeda

2001-01-01

223

Towed-body trajectory tracking in aerial recovery of micro air vehicle in the presence of wind  

Microsoft Academic Search

This paper presents a method for recovering Micro Air Vehicles (MAVs) in flight using a mothership and towed drogue, in which the mothership executes an orbit that places the drogue in a stable, slower orbit that can be tracked by a MAV. This paper is particularly challenging in the presence of wind. The equations of motion of the cable using

Liang Sun; Randal W. Beard

2011-01-01

224

Heavy Metal Contamination of Soil, Plant and Air of Scrapyard of Discarded Vehicles at Zarqa City, Jordan  

Microsoft Academic Search

Ninety soil samples, forty plant samples (Anabasis articulata), and twenty air samples were collected from the scrap yard of discarded vehicles near Zarqa city, Jordan. These samples were analyzed for heavy metals: Cd, Pb, Zn, Cu, Mn, Al, and Fe. Longitudinal and vertical profiles of soil samples were studied. Generally, the levels of all heavy metals studied in the scrap

Qasem M. Jaradat; Adnan Masadeh; Mohammed A. Zaitoun; Baheyah M. Maitah

2005-01-01

225

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

NASA Astrophysics Data System (ADS)

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.

Froning, David

2010-05-01

226

21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2012 CFR

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

2012-04-01

227

21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2011 CFR

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

2011-04-01

228

21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2010 CFR

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

2010-04-01

229

21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2013 CFR

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

2013-04-01

230

21 CFR 872.3540 - OTC denture cushion or pad.  

Code of Federal Regulations, 2014 CFR

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

2014-04-01

231

Chitosan cushioned phospholipid membrane and its application in imaging ellipsometry based-biosensor  

NASA Astrophysics Data System (ADS)

Chitosan cushion can support the air stability of phospholipid membrane, but the problem of serum solubility of phospholipid membrane prevents it from use in serum detection applications. Poly (ethylene glycol) (PEG) shielding promises both stability and non-specific adsorption resistance for phospholipid membrane. An air stable phospholipid membrane microarray has been successfully fabricated on chitosan modified silicon wafer. We have demonstrated the potential application of PEGylated phospholipid membrane in imaging ellipsometry-based protein biosensor. Because of the strong resistance against non-specific adsorption of serum, antigens are immobilized onto the membrane surface through chemical activation and further bind their antibodies without using blocking agent. Taking advantage of the multiple and parallel reaction capabilities of microfluidic reactor system, we have assayed the binding by varying both the density of antigen on the membrane surface and the concentration of antibody in solution.

Zhang, Yibang; Chen, Yanyan; Jin, Gang

2011-09-01

232

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

PubMed

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

Sand-Jensen, Kaj; Hammer, Kathrine Jul

2012-10-01

233

Short communication: Genetic characterization of digital cushion thickness.  

PubMed

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

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

2014-01-01

234

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)

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

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

2010-01-01

235

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

236

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

NASA Astrophysics Data System (ADS)

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

Hall, Asha J.; Riddick, Jaret C.

2012-04-01

237

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

238

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

...leaks at the nominal minimal level of detection for OBD systems (0.020 inch...for High Evaporative Emissions Vehicle Detection: Denver Summer 2008 Pilot Study at...a leak of 0.020 inches which is the detection standard for OBD II...

2013-05-21

239

64 FR 26004 - Control of Air Pollution From New Motor Vehicles: Proposed Tier 2 Motor Vehicle Emissions...  

Federal Register 2010, 2011, 2012, 2013, 2014

...This would be no smaller burden than computing an NMOG average for California vehicles...standards for each model year by separately computing the sales weighted average NO X level...complying with the California ZEV mandate, computing partial and full ZEV allowance...

1999-05-13

240

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

Microsoft Academic Search

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

Erica Zawodny MacArthur; Donald MacArthur; Carl Crane

2005-01-01

241

MODELING, TESTING AND CORRELATION OF INTERLINKED AIR SUSPENSION SYSTEMS FOR PREMIUM VEHICLE PLATFORMS  

Microsoft Academic Search

Since a vehicle is actuated by road irregularities in many different ways the improvement of the passengers driving comfort is a major focus of automotive research and development work especially in the premium vehicle segment. Apart from the acoustic properties of a vehicle generally referred to as NVH (noise vibration harshness), the low- frequent and mechanical kind of vibrations mainly

Michael Frantzen

242

Design and performance of an insect-inspired nano air vehicle  

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

243

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

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

244

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

NASA Astrophysics Data System (ADS)

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.

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

2008-04-01

245

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

NASA Technical Reports Server (NTRS)

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.

Kohout, Lisa L.; Schmitz, Paul C.

2003-01-01

246

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

NASA Technical Reports Server (NTRS)

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.

Beeman, R. R.

1972-01-01

247

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

248

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

NASA Technical Reports Server (NTRS)

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.

Hattis, Philip D.; Malchow, Harvey L.

1991-01-01

249

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

NASA Technical Reports Server (NTRS)

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.

Hattis, Philip D.; Malchow, Harvey L.

1992-01-01

250

Energy dissipation characteristics of rubber crash cushion elements  

E-print Network

to perform satisfactorily in a variety of impact conditions. The ability to reshape and reuse the steel tubular members is also demonstrated. The primary difference between this design and the proposed low-maintenance rubber crash cushion is the goal... better physical properties, better ultraviolet light resistance, and other properties depending on its intended use. About 704 of all natural rubber produced is used in automotive tires, usually composing the carcass and sidewalls [11]. General...

Thompson, Michael Fowlkes

1988-01-01

251

Optimization of aircraft seat cushion fire blocking layers  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

252

Cushioning and lateral stability functions of cloth sport shoes  

Microsoft Academic Search

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 ± 5.9 kg, height 1.50 ± 0.04 m). Cloth sport shoes, running shoes, basketball shoes, cross-training shoes, and barefoot conditions were investigated in random sequence. Human pendulum and cutting movement tests were used to assess

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

2007-01-01

253

Optimal Programming of Multipoint Cushion Systems for Sheet Metal Forming  

Microsoft Academic Search

Numerical optimization technique coupled with finite element analysis of the stamping\\/sheet hydroforming process was developed to predict four possible modes for application of blank holder force (BHF) in multiple-point cushion systems, namely a) BHF constant in space\\/location and time\\/stroke, b) BHF variable in time\\/stroke and constant in space\\/location, c) BHF variable in space\\/location and constant in time\\/stroke and d) BHF

H. Palaniswamy; M. Braedel; A. Thandapani; T. Altan

2006-01-01

254

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

PubMed

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

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

2014-07-01

255

Modeling dispersions in initial conditions for air-launched rockets and their effect on vehicle performance  

E-print Network

Growing interest in air-launched rockets as a method for lofting satellites into orbit motivates the need to investigate the unique challenges that air launch presents. This thesis explores how uncertainties in an air-launched ...

Beerer, Ingrid Mary

2013-01-01

256

Integrated Air/Ground Vehicle System for Semi-Autonomous Off-Road Navigation Tony Stentz (Carnegie Mellon University); axs@cmu.edu  

E-print Network

Integrated Air/Ground Vehicle System for Semi-Autonomous Off-Road Navigation Tony Stentz (Carnegie on the performance of the system. Figure 1: Blitz concept, with Flying Eye scouting for UGV. 2. Perception for Off-Road Pittsburgh, PA 15201 412-268-8155 412-681-6961 (FAX) www.rec.ri.cmu.edu 1. Abstract Current unmanned vehicle

Kelly, Alonzo

257

A study of the dynamics of low energy cushioning material using scale models  

E-print Network

widespread acceptance in the field of cushioning. Ethafoarn's cushioning characteristics are not diminished to a large degree by repeated impacts. Z. TYRILFOAM 50- Tyrilfoam 50 is a white multicellular?molded styrene-acrylonitrile copolymer foam... polyurethane with a density 3 of 1, 9 lb/ft . Of the five materials tested Thurane tends to lose its cushioning ability much more rapidly than the rest on repeated impacts. In some instances the Thurane samples were completely destroyed. The above...

Woolam, William Edward

2012-06-07

258

Roles of TGF? and BMP during valvulo–septal endocardial cushion formation  

Microsoft Academic Search

The primordia of valves and the atrioventricular septum arise from endocardial cushion tissue that is formed in the outflow\\u000a tract (OFT) and in the atrioventricular (AV) regions during cardiogenesis. Abnormal development of the endocardial cushion\\u000a results in various congenital heart diseases. Endocardial epithelial–mesenchymal transformation (EMT) is a critical process\\u000a in cushion tissue formation and is regulated by many factors, such

Toshiyuki Yamagishi; Katsumi Ando; Hiroaki Nakamura

2009-01-01

259

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

PubMed Central

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

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

2006-01-01

260

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

NASA Astrophysics Data System (ADS)

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.

Michel, Silvain; Dürager, Christian; Zobel, Martin; Fink, Erich

2007-04-01

261

Bio-inspired multi-mode optic flow sensors for micro air vehicles  

NASA Astrophysics Data System (ADS)

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 (?-Compound eyes) and to attitude control (?- 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 ?- Compound eyes and ?-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.

Park, Seokjun; Choi, Jaehyuk; Cho, Jihyun; Yoon, Euisik

2013-06-01

262

Emerging Fuel Cell Technology Being Developed: Offers Many Benefits to Air Vehicles  

NASA Technical Reports Server (NTRS)

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.

Walker, James F.; Civinskas, Kestutis C.

2004-01-01

263

Mixed-mode VLSI optic flow sensors for micro air vehicles  

NASA Astrophysics Data System (ADS)

We develop practical, compact optic flow sensors. To achieve the desired weight of 1--2 grams, mixed-mode and mixed-signal VLSI techniques are used to develop compact circuits that directly perform computations necessary to measure optic flow. We discuss several implementations, including a version fully integrated in VLSI, and several "hybrid sensors" in which the front end processing is performed with an analog chip and the back end processing is performed with a microcontroller. We extensively discuss one-dimensional optic flow sensors based on the linear competitive feature tracker (LCFT) algorithm. Hardware implementations of this algorithm are shown able to measure visual motion with contrast levels on the order of several percent. We argue that the development of one-dimensional optic flow sensors is therefore reduced to a problem of engineering. We also introduce two related two-dimensional optic flow algorithms that are amenable to implementation in VLSI. This includes the planar competitive feature tracker (PCFT) algorithm and the trajectory method. These sensors are being developed to solve small-scale navigation problems in micro air vehicles, which are autonomous aircraft whose maximum dimension is on the order of 15 cm. We obtain a proof-of-principle of small-scale navigation by mounting a prototype sensor onto a toy glider and programming the sensor to control a rudder or an elevator to affect the glider's path during flight. We demonstrate the determination of altitude by measuring optic flow in the downward direction. We also demonstrate steering to avoid a collision with a wall, when the glider is tossed towards the wall at a shallow angle, by measuring the optic flow in the direction of the glider's left and right side.

Barrows, Geoffrey Louis

264

The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets  

NASA Technical Reports Server (NTRS)

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.

Anderson, Bernhard H.; Miller, Daniel N.; Gridley, Marvin C.; Agrell, Johan

2003-01-01

265

Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.  

SciTech Connect

This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM2.5). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles. For nearly a decade, Argonne has been evaluating membrane-based methods to control the composition of air used in combustion. Membranes are the only practical method of modifying air composition for on-board use. The applicability of the technique depends strongly on both the technical and economic feasibility of implementing it on a vehicle. Over the past 10 years, significant technical advances have been made in the development of air-separation membranes. Researchers have developed and commercialized novel membrane materials that can efficiently separate air at the concentrations required for vehicle applications and have developed compact membrane modules that can be incorporated into vehicle design. Previous analysis by Argonne and others has demonstrated the effectiveness of oxygen enrichment at reducing PM, smoke, hydrocarbon (HC), and carbon monoxide (CO) emissions while increasing engine power output. Under appropriate oxygen-enriched operating conditions, diesel engines have achieved a net increase of 10-20% in power density and a decrease of 30-60% in PM emissions. Nitrogen-enriched air can be used as an alternative to exhaust gas recirculation to control NO{sub x} emissions and can also be used to generate a monatomic nitrogen plasma for exhaust post-treatment to reduce emissions of NO{sub x}. Argonne has recently identified an operating regime that can simultaneously reduce NO{sub x} and PM while increasing power output when oxygen-enriched combustion air is used. This promising technique, which will be verified by additional experimental work at Argonne (using a range of engine sizes), will require the use of membranes similar to those analyzed in this study.

Poola, R.; Stork, K.

1998-11-09

266

Characterizing the Spatial Variation of Air Pollutants and the Contributions of High Emitting Vehicles in Pittsburgh, PA.  

PubMed

We used a mobile measurement platform to characterize a suite of air pollutants (black carbon (BC), particle-bound polycyclic aromatic hydrocarbons (PB-PAH), benzene, and toluene) in the city of Pittsburgh and surrounding areas. More than 270 h of data were collected from forty-two sites which were selected based on analysis in the geographic information system (GIS). Mobile measurements were performed during three different times of day (mornings, afternoons/evenings, and overnight) in both winter (November 2011 to February 2012) and summer (June 2012 to August 2012). Pollutant concentrations were elevated in river valleys by 9% (benzene) to 30% (PB-PAH) relative to upland areas. Traffic had strong impacts on measured pollutants. PB-PAH and BC concentrations at high traffic sites were a factor of 2 and 30% higher than at low traffic sites, respectively. Pollutant concentrations were highest in the morning sessions due to a combination of traffic and meteorological conditions. The highly time-resolved data indicated that elevated pollutant concentrations at high traffic sites were due to short duration plume events associated with high emitting vehicles. High emitting vehicles contributed up to 70% of the near road PB-PAH and 30% of BC; emissions from these vehicles drove substantial spatial variations in BC and PB-PAH concentrations. Many high emitting vehicles were presumably diesel trucks or buses, because plumes were strongly correlated with truck traffic volume. In contrast, PB-PAH and BC in the nonplume background air was weakly correlated with traffic, and their spatial patterns were more influenced by terrain and point source emissions. The spatial variability in contributions of high emitting vehicles suggests that the effect of potential control strategies vary for different pollutants and environments. PMID:25393032

Tan, Yi; Lipsky, Eric M; Saleh, Rawad; Robinson, Allen L; Presto, Albert A

2014-12-16

267

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

PubMed Central

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

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

2007-01-01

268

Urban air pollution from private vehicles has been declining since the 1970s (1012) even as the number of vehicles and vehicle miles  

E-print Network

), volatile organic compounds (VOC), and ammonia (NH3)] cost 1.3 to 1.4 cents per VMT for automobiles using from 1.1 to 1.2 cents per VMT for compressed nat- ural gas to 1.5 to 1.6 cents per VMT for hybrid-electric vehicles. For 2007, the American Automobile Association (AAA) estimated that the average cost of automobile

Jaramillo, Paulina

269

An efficient fluid-structure interaction method for conceptual design of flexible micro air vehicle wings: Development, comparison, and application  

NASA Astrophysics Data System (ADS)

This thesis summarizes the development, comparison, and applications of an efficient fluid-structure interaction method capable of simulating the effects that wing flexibility has on micro air vehicle (MAV) performance. Micro air vehicles wing designs often incorporate flexible wing structures that mimic the skeleton / membrane designs found in natural flyers such as bats and insects. However, accurate performance prediction for these wings requires the coupling of the simulation of the fluid physics around the wing and the simulation of the structural deformation. These fluid-structure interaction (FSI) simulations are often accomplished using high fidelity, computationally expensive techniques such as computational fluid dynamics (CFD) for the fluid physics and nonlinear finite element analysis (FEA) for the structural simulation. The main drawback of these methods, especially for use simulating vehicles that are able to be manufactured relatively quickly, is that the computational cost required to perform relevant trade studies on the design is prohibitively large and time-consuming. The main goal of this research is the development of a coupled fluid-structure interaction method computationally efficient and accurate enough to be used for conceptual design of micro air vehicles. An advanced potential flow model is used to calculate aerodynamic performance and loading, while a simplified finite element structural model using frame and shell elements calculates the wing deflection due to aerodynamic loading. The contents of this thesis include a literature survey of current approaches, an introduction to the efficient FSI formulation, comparison of the presented FSI method with higher-fidelity simulation methods, demonstrations of the method's capability for tradeoff and optimization studies, and an overview of contributions to a nonlinear dynamic algorithm for the simulation of flapping flight.

Combes, Thomas P.

270

A COMPARISON OF THE CUSHIONING EFFECT OF A POPULAR RUNNING SHOE AND A SHOE USING A NEW SPRING TECHNOLOGY DURING RUNNING  

Microsoft Academic Search

The purpose of the study was to compare the cushioning effect of the Nike Air Pegasus 2004 and the Spira Volare IITM during running. Measured variables were peak force, peak force relative to body weight and time-to-peak force. It was determined that time-to- peak force was not significantly different (p=0.1745) between the Spira and the Nike. There were significant differences

Mike Flores; Darla R. Smith

271

Investigation of the Landing Characteristics of a Re-entry Vehicle Having a Canted Multiple Air Bag Load Alleviation System  

NASA Technical Reports Server (NTRS)

An investigation was made to determine the landing-impact characteristics of a reentry vehicle having a multiple-air-bag load-alleviation system. A 1/16-scale dynamic model having four canted air bags was tested at flight-path angles of 90 degrees (vertical), 45 degrees, and 27 degrees for a parachute or paraglider vertical letdown velocity of 30 feet per second (full scale). Landings were made on concrete at attitudes ranging from -l5 degrees to 20 degrees. The friction coefficient between the model heat shield and the concrete was approximately 0.4. An aluminum diaphragm, designed to rupture at 10.8 pounds per square inch gage, was used to maintain initial pressure in the air bags for a short time period.

McGehee, John R.; Stubbs, Sandy M.

1963-01-01

272

An experimental investigation of a micro air vehicle-scale cycloidal rotor in forward flight  

NASA Astrophysics Data System (ADS)

The current research aims to explore the forward flight capability of an unconventional rotary-wing concept for micro air vehicle (MAV) applications, known as the cycloidal rotor (or cyclorotor). Two approaches are undertaken to fulfill this objective: 1) performance studies to examine the time-averaged forces produced by the cyclorotor, and 2) flow field studies to investigate the underlying physics of force production. In the performance studies, the dependence of time-averaged lift, propulsive force and power on blade pitching kinematics, rotor geometry and forward flight operating conditions (i.e. advance ratio) were first examined through independent parametric studies. Next, the performance results were interpolated to determine the steady level flight characteristics of the cyclorotor, specifically the power consumption, lift-to-drag ratio and control input requirements at various forward speeds. The baseline values of lift and rotational speed for these trimmed flight studies were determined based on an existing twin-cyclorotor MAV. These studies showed the cyclorotor to be capable of achieving relatively high advance ratios (up to 0.94), with significant reductions in power consumption. In the second research approach, flow visualization experiments and time-resolved, planar particle image velocimetry (PIV) measurements were performed to gain a qualitative and quantitative understanding of the flow field. The time-averaged and phase-averaged flow fields of a 2-bladed cyclorotor were examined at different advance ratios. The PIV measurements were then correlated with previous computational fluid dynamics (CFD) simulations to help explain the distribution of forces along the rotor azimuth. The flow field studies revealed that the cyclorotor needs to operate in the counter-clockwise direction (freestream velocity from left to right) in order to produce the necessary lift force in high-speed forward flight, the primary lift and propulsive force producing regions of the cyclorotor are located in the lower-rear half of the rotor azimuth (symmetric pitching kinematics), and that unsteady aerodynamics (e.g. blade-vortex interactions) plays an important role in the generation of lift and propulsive blade force production.

Jarugumilli, Tejaswi

273

Study on control of air suspension system for railway vehicle to prevent wheel load reduction at low-speed transition curve negotiation  

Microsoft Academic Search

This article presents the curving performance of railway vehicles with air suspensions. Air suspensions sometimes cause reduction of wheel load at transition curve, which will reduce the margin for the safety of curve passing. And it may be the reason of derailment. In this study, the reduction of wheel load was restrained by using the new concept devices. The proposed

Y. Suda; W. Wang; H. Komine; Y. Sato; T. Nakai; Y. Shimokawa

2006-01-01

274

Air quality impacts of plug-in hybrid electric vehicles in Texas: evaluating three battery charging scenarios  

NASA Astrophysics Data System (ADS)

The air quality impacts of replacing approximately 20% of the gasoline-powered light duty vehicle miles traveled (VMT) with electric VMT by the year 2018 were examined for four major cities in Texas: Dallas/Ft Worth, Houston, Austin, and San Antonio. Plug-in hybrid electric vehicle (PHEV) charging was assumed to occur on the electric grid controlled by the Electricity Reliability Council of Texas (ERCOT), and three charging scenarios were examined: nighttime charging, charging to maximize battery life, and charging to maximize driver convenience. A subset of electricity generating units (EGUs) in Texas that were found to contribute the majority of the electricity generation needed to charge PHEVs at the times of day associated with each scenario was modeled using a regional photochemical model (CAMx). The net impacts of the PHEVs on the emissions of precursors to the formation of ozone included an increase in NOx emissions from EGUs during times of day when the vehicle is charging, and a decrease in NOx from mobile emissions. The changes in maximum daily 8 h ozone concentrations and average exposure potential at twelve air quality monitors in Texas were predicted on the basis of these changes in NOx emissions. For all scenarios, at all monitors, the impact of changes in vehicular emissions, rather than EGU emissions, dominated the ozone impact. In general, PHEVs lead to an increase in ozone during nighttime hours (due to decreased scavenging from both vehicles and EGU stacks) and a decrease in ozone during daytime hours. A few monitors showed a larger increase in ozone for the convenience charging scenario versus the other two scenarios. Additionally, cumulative ozone exposure results indicate that nighttime charging is most likely to reduce a measure of ozone exposure potential versus the other two scenarios.

Thompson, Tammy M.; King, Carey W.; Allen, David T.; Webber, Michael E.

2011-04-01

275

Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales  

NASA Astrophysics Data System (ADS)

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.

McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

2012-09-01

276

Long-term trends in nitrogen oxide emissions from motor vehicles at national, state, and air basin scales  

NASA Astrophysics Data System (ADS)

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.

McDonald, Brian C.; Dallmann, Timothy R.; Martin, Elliot W.; Harley, Robert A.

2011-11-01

277

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

Code of Federal Regulations, 2010 CFR

...Handling, Care, Treatment, and Transportation of Warmblooded Animals Other Than Dogs, Cats, Rabbits, Hamsters, Guinea Pigs, Nonhuman Primates, and Marine Mammals Transportation Standards § 3.138 Primary conveyances (motor vehicle,...

2010-01-01

278

Integrated Air\\/Ground Vehicle System for SemiAutonomous Off-Road Navigation  

Microsoft Academic Search

1.Abstract Current unmanned vehicle systems enable exploration of and travel through remote areas, but demand significant ,communications resources and constant human operation. DARPA and the US Army have,recognized these limitations and are now,pursuing semi-autonomous vehicle systems in the Future Combat Systems (FCS) program. FCS places high demands on robotic systems, which must assess mobility hazards under all weather conditions, day

Tony Stentz; Alonzo Kelly; Robert Mandelbaum; Peter Rander

2002-01-01

279

International Conference 'Transport and Air Pollution' 2008, Graz EMISSION FACTOR MODELLING FOR LIGHT VEHICLES  

E-print Network

- 1 - 16th International Conference 'Transport and Air Pollution' 2008, Graz EMISSION FACTOR in Europe: The European MEET (Methodologies for Estimating air pollutant Emissions from Transport) project. Transport and Air Pollution, Graz : Austria (2008)" #12;- 2 - 16th International Conference 'Transport

Paris-Sud XI, Université de

280

73 FR 12354 - Federal Motor Vehicle Safety Standards No. 121; Air Brake Systems  

Federal Register 2010, 2011, 2012, 2013, 2014

...that activates the air compressor (cut-in pressure) and then turns off the air compressor once the reservoirs...brake pedal (treadle valve). Therefore, a light...directly from the air compressor. The primary and secondary...equipped with check valves for isolation so...

2008-03-07

281

Model prediction of vibration effects on human subject seated on various cushions  

Microsoft Academic Search

Vertical and horizontal vibrations of a 100 kg seated human body on cushions of various mechanical parameters have been investigated. The vibration inputs were from (a) steering, (b) cushion and (c) a combination of the two. A previously developed model has been used in this study. Resonance frequencies and gains of body segments have been found. The results obtained have

W. Qassem

1996-01-01

282

Experimental and predicted pressure and heating distributions for an Aeroassist Flight Experiment vehicle in air at Mach 10  

NASA Technical Reports Server (NTRS)

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.

Micol, John R.

1989-01-01

283

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

NASA Technical Reports Server (NTRS)

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.

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

1980-01-01

284

Cooperative Electronic Attack for Groups of Unmanned Air Vehicles based on Multi-agent Simulation and Evaluation  

E-print Network

In this paper, the issue of path planning is addressed for unmanned air vehicles (UAVs) cooperative joint-forces electronic attack operating in a hostile environment. Specifically, the objective is to plan path to a target location in a way that minimizes exposure to threats while keeping fuel usage at acceptable levels. We consider a scenario where a group of UAVs flies in a close formation and cooperates in their use of jamming resources to prevent being tracked by Surface-to-Air Missile (SAM) tracking radars. The main goal of this research effort is develop cooperating UAVs within multi-agent simulation environment. Simulations were generated to test the path planning and control strategies given UAVs/SAM tracking radar network scenarios, and overall UAVs cooperative electronic attack performance in each simulation was analyzed.

Yee Ming; Chen Wen-yuan Wu

285

Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system  

SciTech Connect

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.

Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

1989-04-01

286

Hover and wind-tunnel testing of shrouded rotors for improved micro air vehicle design  

NASA Astrophysics Data System (ADS)

The shrouded-rotor configuration has emerged as the most popular choice for rotary-wing Micro Air Vehicles (MAVs), because of the inherent safety of the design and the potential for significant performance improvements. However, traditional design philosophies based on experience with large-scale ducted propellers may not apply to the low-Reynolds-number (˜20,000) regime in which MAVs operate. An experimental investigation of the effects of varying the shroud profile shape on the performance of MAV-scale shrouded rotors has therefore been conducted. Hover tests were performed on seventeen models with a nominal rotor diameter of 16 cm (6.3 in) and various values of diffuser expansion angle, diffuser length, inlet lip radius and blade tip clearance, at various rotor collective angles. Compared to the baseline open rotor, the shrouded rotors showed increases in thrust by up to 94%, at the same power consumption, or reductions in power by up to 62% at the same thrust. These improvements surpass those predicted by momentum theory, due to the additional effect of the shrouds in reducing the non-ideal power losses of the rotor. Increasing the lip radius and decreasing the blade tip clearance caused performance to improve, while optimal values of diffuser angle and length were found to be 10 and 50% of the shroud throat diameter, respectively. With the exception of the lip radius, the effects of changing any of the shrouded-rotor parameters on performance became more pronounced as the values of the other parameters were changed to degrade performance. Measurements were also made of the wake velocity profiles and the shroud surface pressure distributions. The uniformity of the wake was improved by the presence of the shrouds and by decreasing the blade tip clearance, resulting in lower induced power losses. For high net shroud thrust, a favorable pressure distribution over the inlet was seen to be more important than in the diffuser. Strong suction pressures were observed above the blade-passage region on the inlet surface; taking advantage of this phenomenon could enable further increases in thrust. However, trade studies showed that, for a given overall aircraft size limitation, and ignoring considerations of the safety benefits of a shroud, a larger-diameter open rotor is more likely to give better performance than a smaller-diameter shrouded rotor. The open rotor and a single shrouded-rotor model were subsequently tested at a single collective in translational flight, at angles of attack from 0° (axial flow) to 90° (edgewise flow), and at various advance ratios. In axial flow, the net thrust and the power consumption of the shrouded rotor were lower than those of the open rotor. In edgewise flow, the shrouded rotor produced greater thrust than the open rotor, while consuming less power. Measurements of the shroud surface pressure distributions illustrated the extreme longitudinal asymmetry of the flow around the shroud, with consequent pitch moments much greater than those exerted on the open rotor. Except at low airspeeds and high angles of attack, the static pressure in the wake did not reach ambient atmospheric values at the diffuser exit plane; this challenges the validity of the fundamental assumption of the simple-momentum-theory flow model for short-chord shrouds in translational flight.

Pereira, Jason L.

287

Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle  

NASA Technical Reports Server (NTRS)

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.

Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

2004-01-01

288

Acute effects of motor vehicle traffic-related air pollution exposures on measures of oxidative stress in human airways  

PubMed Central

Epidemiological studies have linked exposure to traffic-related air pollutants to increased respiratory and cardiovascular morbidity and mortality. Evidence from human, animal, and in vitro studies supports an important role for oxidative stress in the pathophysiological pathways underlying the adverse health effects of air pollutants. In controlled-exposure studies of animals and humans, emissions from diesel engines, a major source of traffic-related air pollutants, cause pulmonary and systemic inflammation that is mediated by redox-sensitive signaling pathways. Assessment of human responses to traffic-related air pollution under realistic conditions is challenging due to the complex, dynamic nature of near-roadway exposure. Noninvasive measurement of biomarkers in breath and breath condensate may be particularly useful for evaluating the role of oxidative stress in acute responses to exposures that occur in vehicles or during near-roadway activities. Promising biomarkers include nitric oxide in exhaled breath, and nitrite/nitrate, malondialdehyde, and F2-isoprostanes in exhaled breath condensate. PMID:20716291

Laumbach, Robert J.; Kipen, Howard M.

2014-01-01

289

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 ...

290

DESIGN AND DEVELOPMENT OF A MICRO AIR VEHICLE (AV) CONCEPT: PROJECT BIDULE  

E-print Network

to the wing loading and a high maximum lift. The wind tunnel testing of a propelled model of the "Bidule, propeller effects, wind tunnel. Introduction The concept of micro-sized Unmanned Aerial Vehicles (UAVs immersed in a propeller slipstream, providing that the destabilising effects due to the power system

Wong, K. C.

291

ANALYSIS OF MOTOR VEHICLE EMISSIONS IN A HOUSTON TUNNEL DURING THE TEXAS AIR QUALITY STUDY 2000  

EPA Science Inventory

Measurements from a Houston tunnel were used to develop fuel consumption based emission factors for CO, NOx, and Non-Methane Organic Compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (pr...

292

Research Positionsfor Development of Novel Green Air Conditioning and Refrigeration Systems for Transportation Vehicles  

E-print Network

vehicles and reefers under various driving cycles and climates; ii) Development of nextgeneration system inside the cabin and refrigerated compartment; iii) Design and development of new vapor compression A/CR featuring Liion batteries and regenerative auxiliary power systems; iv) Development

Bahrami, Majid

293

PEGylated phospholipid membrane on polymer cushion and its interaction with cholesterol.  

PubMed

By employing poly(ethylene glycol) (PEG) shielding and a polymer cushion to achieve air stability of the lipid membrane, we have analyzed PEG influence on dried membranes and the interaction with cholesterol. Small unilamellar vesicles (SUVs) formed by the mixture of 1,2-dimyristoylphosphatidylcholine (DMPC) with different molar fraction of 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000] (DSPE-PEG(2000)) adsorb and fuse into membranes on different polymer-modified silicon dioxide surfaces, including chitosan, poly(L-lysine) (PLL), and hyaluronic acid. Dried membranes are further examined by ellipsometer and atomic force microscopy (AFM). Only chitosan can support a visible and uniform lipid array. The thickness of dry PEGylated lipid membrane is reduced gradually as the molar fraction of PEG increases. AFM scanning confirms the lipid membrane stacking for vesicles containing low PEG, and only a proper amount of PEG can maintain a single lipid bilayer; however, the air stability of the membrane will be destroyed if overloading PEG. Cholesterol incorporation can greatly improve the structural stability of lipid membrane, especially for those containing high molar fraction of PEG. Different amounts of cholesterol influence the thickness and surface morphology of dried membrane. PMID:20415472

Zhang, Yibang; Chen, Yanyan; Jin, Gang

2010-07-01

294

BMP-2 induces versican and hyaluronan that contribute to post-EMT AV cushion cell migration.  

PubMed

Distal outgrowth and maturation of mesenchymalized endocardial cushions are critical morphogenetic events during post-EMT atrioventricular (AV) valvuloseptal morphogenesis. We explored the role of BMP-2 in the regulation of valvulogenic extracellular matrix (ECM) components, versican and hyaluronan (HA), and cell migration during post-EMT AV cushion distal outgrowth/expansion. We observed intense staining of versican and HA in AV cushion mesenchyme from the early cushion expansion stage, Hamburger and Hamilton (HH) stage-17 to the cushion maturation stage, HH stage-29 in the chick. Based on this expression pattern we examined the role of BMP-2 in regulating versican and HA using 3D AV cushion mesenchymal cell (CMC) aggregate cultures on hydrated collagen gels. BMP-2 induced versican expression and HA deposition as well as mRNA expression of versican and Has2 by CMCs in a dose dependent manner. Noggin, an antagonist of BMP, abolished BMP-2-induced versican and HA as well as mRNA expression of versican and Has2. We further examined whether BMP-2-promoted cell migration was associated with expression of versican and HA. BMP-2- promoted cell migration was significantly impaired by treatments with versican siRNA and HA oligomer. In conclusion, we provide evidence that BMP-2 induces expression of versican and HA by AV CMCs and that these ECM components contribute to BMP-2-induced CMC migration, indicating critical roles for BMP-2 in distal outgrowth/expansion of mesenchymalized AV cushions. PMID:24147033

Inai, Kei; Burnside, Jessica L; Hoffman, Stanley; Toole, Bryan P; Sugi, Yukiko

2013-01-01

295

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)

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.

Havill, C. D.

1974-01-01

296

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

Code of Federal Regulations, 2010 CFR

...sufficient air. (d) Primary transport enclosures must be positioned in primary conveyances in such a manner...of animal cargo spaces in primary conveyances must be kept...material, substance, or device that may be injurious...

2010-01-01

297

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

Code of Federal Regulations, 2012 CFR

...sufficient air. (d) Primary transport enclosures must be positioned in primary conveyances in such a manner...of animal cargo spaces in primary conveyances must be kept...material, substance, or device that may be injurious...

2012-01-01

298

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

Code of Federal Regulations, 2013 CFR

...sufficient air. (d) Primary transport enclosures must be positioned in primary conveyances in such a manner...of animal cargo spaces in primary conveyances must be kept...material, substance, or device that may be injurious...

2013-01-01

299

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

Code of Federal Regulations, 2011 CFR

...sufficient air. (d) Primary transport enclosures must be positioned in primary conveyances in such a manner...of animal cargo spaces in primary conveyances must be kept...material, substance, or device that may be injurious...

2011-01-01

300

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

Code of Federal Regulations, 2014 CFR

...sufficient air. (d) Primary transport enclosures must be positioned in primary conveyances in such a manner...of animal cargo spaces in primary conveyances must be kept...material, substance, or device that may be injurious...

2014-01-01

301

Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers  

PubMed Central

Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the active charcoal combination filter appeared less inflammatory to A549 cells. Conclusions A cabin air inlet particle filter including an active charcoal component was highly effective in reducing both DE particulate and gaseous components, with reduced exhaust-induced symptoms in healthy volunteers. These data demonstrate the effectiveness of cabin filters to protect subjects travelling in vehicles from diesel exhaust emissions. PMID:24621126

2014-01-01

302

Pair plasma cushions in the hole-boring scenario  

NASA Astrophysics Data System (ADS)

Pulses from a 10 PW laser are predicted to produce large numbers of gamma-rays and electron-positron pairs on hitting a solid target. However, a pair plasma, if it accumulates in front of the target, may partially shield it from the pulse. Using stationary, one-dimensional solutions of the two-fluid (electron-positron) and Maxwell equations, including a classical radiation reaction term, we examine this effect in the hole-boring scenario. We find the collective effects of a pair plasma ‘cushion’ substantially reduce the reflectivity, converting the absorbed flux into high-energy gamma-rays. There is also a modest increase in the laser intensity needed to achieve threshold for a non-linear pair cascade.

Kirk, J. G.; Bell, A. R.; Ridgers, C. P.

2013-09-01

303

A Small SemiAutonomous Rotary-Wing Unmanned Air Vehicle (UAV)  

Microsoft Academic Search

Small radio controlled (R\\/C) rotary-wing UAVs have many potential military and civilian applications, but can be very difficult to fly. Small and lightweight sensors and computers can be used to implement a control system to make these vehicles easier to fly. To develop a control system for a small UAV, an 8-bit microcontroller has been interfaced with MEMS (Micro-Electro-Mechanical Systems)

Scott D. Hanford; Lyle N. Long; Joseph F. Horn

2005-01-01

304

Design and development of effective manual control system for unmanned air vehicle  

Microsoft Academic Search

Unmanned Aerial Vehicles (UAVs) are remotely piloted or self-piloted aircraft that are capable of flight without any on-board operator and can carry cameras, sensors, communications equipment or other payloads. UAVs have been used in a reconnaissance and intelligence-gathering role, including combat and rescue missions. This paper describes development and implementation of remote manual control system for a UAV. The paper

Muhammad Aamir Zafar; Ansar Rauf; Zeeshan Ashraf; Humza Akhtar

2011-01-01

305

Analysis of motor vehicle emissions in a Houston tunnel during the Texas Air Quality Study 2000  

Microsoft Academic Search

Measurements from a Houston tunnel were used to develop fuel consumption-based emission factors for CO, NOx, and non-methane organic compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (primarily pre-1996) tunnel studies while the NMOC emission factor was slightly higher than that reported in the previous tunnel

Gary R. McGaughey; Nimish R. Desai; David T. Allen; Robert L. Seila; William A. Lonneman; Matthew P. Fraser; Robert A. Harley; Alison K. Pollack; Jason M. Ivy; James H. Price

2004-01-01

306

A Feasibility Study on the Control of a Generic Air Vehicle Using Control Moment Gyros  

NASA Technical Reports Server (NTRS)

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.

Lim, Kyong B.; Moerder, Daniel D.

2006-01-01

307

The optimization of aircraft seat cushion fire-blocking layers. Full Scale: Test description and results  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

308

Lateral Deflections of Webs in Air-Flotation Ovens  

E-print Network

­ lateral tilt angle of air-bar, in radians ­ spring constant of air cushion supporting web over bar ­ webLateral Deflections of Webs in Air-Flotation Ovens Peter M. Moretti March 2, 2001 Abstract A long web span supported by many, regularly spaced, alternating air- bars is studied. The focus

309

Mixed-mode VLSI optic flow sensors for in-flight control of a micro air vehicle  

NASA Astrophysics Data System (ADS)

NRL is developing compact optic flow sensors for use in a variety of small-scale navigation and collision avoidance tasks. These sensors are being developed for use in micro air vehicles (MAVs), which are autonomous aircraft whose maximum dimension is on the order of 15 cm. To achieve desired weight specifications of 1 - 2 grams, mixed-signal VLSI circuitry is being used to develop compact focal plane sensors that directly compute optic flow. As an interim proof of principle, we have constructed a sensor comprising a focal plane sensor head with on-chip processing and a back-end PIC microcontroller. This interim sensors weighs approximately 25 grams and is able to measure optic flow with real-world and low-contrast textures. Variations of this sensor have been used to control the flight of a glider in real-time to avoid collisions with walls.

Barrows, Geoffrey L.; Neely, C.

2000-11-01

310

Experimental Investigation of Project Orion Crew Exploration Vehicle Aeroheating: LaRC 20-Inch Mach 6 Air Tunnel Test 6931  

NASA Technical Reports Server (NTRS)

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.

Hollis, Brian R.

2009-01-01

311

A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System  

NASA Technical Reports Server (NTRS)

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.

VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

2008-01-01

312

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

NASA Technical Reports Server (NTRS)

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)

2006-01-01

313

Testing of aircraft passenger seat cushion materials. Full scale, test description and results, volume 1  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

314

INCORPORATION OF PASSIVE WING FOLDING IN FLAPPING WING MINIATURE AIR VEHICLES  

Microsoft Academic Search

Flapping wing motion produces positive lift in the down stroke and negative lift in the upstroke under zero forward velocity. Large birds frequently exhibit flight behavior where their wings are folded during the upstroke, thus lowering the air resistance as the wing is moved upwards. The result is reduced magnitude of negative lift produced during the upstroke, relative to the

Dominik Mueller; John W. Gerdes; Satyandra K. Gupta

315

Voltage clamping of Xenopus laevis oocytes utilizing agarose-cushion electrodes  

Microsoft Academic Search

Two-electrode voltage clamping of expressed ion channels in intact oocytes of the South African clawed frog Xenopus laevis has been refined to allow stable, low-resistance electrical access to the cytosol (50–800 kO). Glass microelectrodes were filled with a cushion of 1 % agarose at their tips to prevent KC1 leakage (agarose-cushion electrodes). Insertion of these electrodes into X. laevis oocytes

Wolfgang Schreibmayer; Henry A. Lester; Nathan Dascal

1994-01-01

316

Progress on "pico" air vehicles R.J. Wood, B. Finio, M. Karpelson, K. Ma, N.O. Perez-Arancibia, P.S. Sreetharan,  

E-print Network

of a flapping-wing robotic insect. These include a butterfly-like ornithopter from the University of Tokyo [1 ornithopters and RC helicopters on the scale of micro air vehicles such as the Silverlit `iBird' and the Wowwee

Wood, Robert

317

Implementation of the Rauch-Tung-Striebel smoother for sensor compatibility correction of a fixed-wing unmanned air vehicle.  

PubMed

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

Chan, Woei-Leong; Hsiao, Fei-Bin

2011-01-01

318

Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle  

PubMed Central

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

Chan, Woei-Leong; Hsiao, Fei-Bin

2011-01-01

319

Vehicle emissions  

NSDL National Science Digital Library

Air pollution in the United States is a major problem; transportation plays a major role in air pollution. This informational piece, part of a series about the future of energy, provides students with data on pollution caused by vehicles. Pollutants covered include carbon monoxide, nitrogen oxide, sulfur dioxide, and lead, among others. Copyright 2005 Eisenhower National Clearinghouse

Project, Iowa P.

2004-01-01

320

Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.  

PubMed

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

Lee, Eon S; Zhu, Yifang

2014-02-18

321

Vehicle suspension apparatus  

Microsoft Academic Search

A vehicle suspension apparatus is described comprising: suspension units each provided for each wheel and each having an air spring chamber; a reservoir tank for storing compressed air to be supplied through an air supply valve to the air spring chambers of the suspension units; exhausting means for exhausting compressed air from the air spring chambers of the suspension units

M. Tatemoto; N. Kumagai; H. Abe; S. Takizawa; T. Tanaka; S. Chikamori; M. Harara; Y. Taniguchi; M. Suzumura

1987-01-01

322

Massachusetts Electric Vehicle Efforts  

E-print Network

Massachusetts Electric Vehicle Efforts Christine Kirby, MassDEP ZE-MAP Meeting October 24, 2014 #12 · Provide Clean Air · Grow the Clean Energy Economy · Electric vehicles are a key part of the solution #12 is promoting EVs 4 #12;TCI and Electric Vehicles · Established the Northeast Electric Vehicle Network through

California at Davis, University of

323

Composed cushions and coexistence with neighbouring species promoting the persistence of Eritrichium nanum in high alpine vegetation  

Microsoft Academic Search

.  Zoller H. and Lenzin H. 2006. Composed cushions and coexistence with neighbouring species promoting the persistence of Eritrichium nanum in high alpine vegetation. Bot. Helv. 116: 31–40.\\u000a \\u000a Cushions of high alpine plants may consist of several individuals, either of the same or of different species (composed cushions).\\u000a To clarify the role of this coexistence for the life history of alpine

Heinrich Zoller; Heiner Lenzin

2006-01-01

324

Verification and Tuning of an Adaptive Controller for an Unmanned Air Vehicle  

NASA Technical Reports Server (NTRS)

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.

Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

2010-01-01

325

Unmanned air vehicle flow separation control using dielectric barrier discharge plasma at high wind speed  

NASA Astrophysics Data System (ADS)

The present paper described an experimental investigation of separation control of an Unmanned Aerial Vehicle (UAV) at high wind speeds. The plasma actuator was based on Dielectric Barrier Discharge (DBD) and operated in a steady manner. The flow over a wing of UAV was performed with smoke flow visualization in the ?0.75 m low speed wind tunnel to reveal the flow structure over the wing so that the locations of plasma actuators could be optimized. A full model of the UAV was experimentally investigated in the ?3.2 m low speed wind tunnel using a six-component internal strain gauge balance. The effects of the key parameters, including the locations of the plasma actuators, the applied voltage amplitude and the operating frequency, were obtained. The whole test model was made of aluminium and acted as a cathode of the actuator. The results showed that the plasma acting on the surface of UAV could obviously suppress the boundary layer separation and reduce the model vibration at the high wind speeds. It was found that the maximum lift coefficient of the UAV was increased by 2.5% and the lift/drag ratio was increased by about 80% at the wind speed of 100 m/s. The control mechanism of the plasma actuator at the test configuration was also analyzed.

Zhang, Xin; Huang, Yong; Wang, WanBo; Wang, XunNian; Li, HuaXing

2014-06-01

326

The best for the guest: high Andean nurse cushions of Azorella madreporica enhance arbuscular mycorrhizal status in associated plant species.  

PubMed

Positive interactions between cushion plant and associated plants species in the high Andes of central Chile should also include the effects of fungal root symbionts. We hypothesized that higher colonization by arbuscular mycorrhizal (AM) fungi exists in cushion-associated (nursling) plants compared with conspecific individuals growing on bare ground. We assessed the AM status of Andean plants at two sites at different altitudes (3,200 and 3,600 ma.s.l.) in 23 species, particularly in cushions of Azorella madreporica and five associated plants; additionally, AM fungal spores were retrieved from soil outside and beneath cushions. 18 of the 23 examined plant species presented diagnostic structures of arbuscular mycorrhiza; most of them were also colonized by dark-septate endophytes. Mycorrhization of A. madreporica cushions showed differences between both sites (68% and 32%, respectively). In the native species Hordeum comosum, Nastanthus agglomeratus, and Phacelia secunda associated to A. madreporica, mycorrhization was six times higher than in the same species growing dispersed on bare ground at 3,600 ma.s.l., but mycorrhiza development was less cushion dependent in the alien plants Cerastium arvense and Taraxacum officinale at both sites. The ratio of AM fungal spores beneath versus outside cushions was also 6:1. The common and abundant presence of AM in cushion communities at high altitudes emphasizes the importance of the fungal root symbionts in such situations where plant species benefit from the microclimatic conditions generated by the cushion and also from well-developed mycorrhizal networks. PMID:21384201

Casanova-Katny, M Angélica; Torres-Mellado, Gustavo Adolfo; Palfner, Goetz; Cavieres, Lohengrin A

2011-10-01

327

Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle  

PubMed Central

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

Zhang, G. Q.; Yu, S. C. M.

2014-01-01

328

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)

The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3) will be available to destroy it. Results for the scenarios involving hydrogen from wind and coal gasification, and from the hybrid scenario will also be discussed, as will regional climate effects (including effects of H2O). Findings to date suggest that, even under a worst-case scenario of 10% hydrogen leakage, the conversion of the current fleet to hydrogen-fuel cell vehicles, where hydrogen is generated by steam-reforming of methane, may result in a measurable improvement in U.S. air quality.

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

2004-12-01

329

Sensitivity of urban airshed model results for test fuels to uncertainties in light-duty vehicle and biogenic emissions and alternative chemical mechanisms—Auto\\/oil air quality improvement research program  

Microsoft Academic Search

Three sources of uncertainty in the air quality modeling performed for the Auto\\/Oil Air Quality Improvement: Research Program, Phase I, were investigated to assess their impact on predicted ozone for test fuels in Los Angeles in year 2010. First, quadrupling the estimated total organic gas (TOG) and tripling the CO emissions from light-duty gasoline vehicles in the air quality model

Charles H. Schleyer

1995-01-01

330

40 CFR 1066.810 - Vehicle preparation.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Vehicle preparation. 1066.810 Section...CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Exhaust Emission Test Procedures for Motor Vehicles § 1066.810 Vehicle...

2014-07-01

331

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

PubMed Central

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. PMID:21151351

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

2011-01-01

332

Design of a High-Altitude Long-Endurance Solar-Powered Unmanned Air Vehicle for Multi-Payload and Operations  

Microsoft Academic Search

Several researches are being carried out at the Politecnico di Torino with the aim of designing a high altitude very-long endurance\\/unmanned air vehicle (HAVE\\/UAV). Being able to fly in the stratosphere (15-20 km) and with an endurance of about 4 months offers an advan- tage and possibility that is presently not available with conventional aircraft or satellites. A computer program

G Romeo; G Frulla; E Cestino

2007-01-01

333

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

PubMed

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 the benefits of past control measures. PMID:25122954

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

2014-07-01

334

KCP Activities Supporting the W76LEP Stress Cushions and LK3626 RTV Replacement Material Development  

SciTech Connect

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.

J. W. Schneider

2009-10-01

335

20/07/2011 09:30Will male cottony cushion scales survive their own mating strategy? | Molecular Love (and other facts of life) Page 1 of 3http://nittygrittyscience.com/2011/07/19/will-male-cottony-cushion-...=will-male-cottony-cushion-scales-survive-their  

E-print Network

scale and her offspring. Image via NY Times. Will male cottony cushion scales survive their own mating to this article in the New York Times Science section today. An insect known as the cottony cushion scale (Icerya as the male part of the insect and all0ws her to fertilize her own eggs. So, if the hermaphrodites can just

Gardner, Andy

336

The Bottom Line For Air Quality.  

ERIC Educational Resources Information Center

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.…

Ellis, Tom

2000-01-01

337

Ethical and economic issues in the use of zero-emission vehicles as a component of an air-pollution mitigation strategy.  

PubMed

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

Duvall, Tim; Englander, Fred; Englander, Valerie; Hodson, Thomas J; Marpet, Mark

2002-10-01

338

Distribution of Tardigrades within a Moss Cushion: Do Tardigrades Migrate in Response to Changing Moisture Conditions?  

Microsoft Academic Search

The distribution of tardigrades within the layers of the cushion moss Grimmia alpicola Hedwig, 1801 was investigated. The aim of this study was to determine the tardigrade species present within the moss layers during both wet and dry periods and to determine if migration occurred in response to changing moisture conditions. Samples of the moss were removed from concrete caps

Diane R. Nelson; Rebecca G. Adkins

2001-01-01

339

A global meta-analytic contrast of cushion-plant effects on plants and on arthropods  

PubMed Central

Nurse plant facilitation is a commonly reported plant–plant interaction and is an important factor influencing community structure in stressful environments. Cushion plants are an example of alpine nurse plants that modify microclimatic conditions within their canopies to create favourable environments for other plants. In this meta-analysis, the facilitative effects of cushion plants was expanded from previous syntheses of the topic and the relative strength of facilitation for other plants and for arthropods were compared globally.The abundance, diversity, and species presence/absence effect size estimates were tested as plant responses to nurse plants and a composite measure was tested for arthropods. The strength of facilitation was on average three times greater for arthropods relative to all plant responses to cushions. Plant species presence, i.e., frequency of occurrence, was not enhanced by nurse-plants. Cushion plants nonetheless acted as nurse plants for both plants and arthropods in most alpine contexts globally, and although responses by other plant species currently dominate the facilitation literature, preliminary synthesis of the evidence suggests that the potential impacts of nurses may be even greater for other trophic levels. PMID:24688848

Liczner, Amanda R.

2014-01-01

340

A comparison of interface pressure readings to wheelchair cushions and positioning: a pilot study.  

PubMed

Occupational therapists are often involved in assessing the seating needs of clients who have quadriplegia. One component of this process involves determining the appropriate use of wheelchair cushions and pressure relieving techniques in the prevention of pressure sores. The purpose of this study was to assess the effect of tilt and recline positioning and various wheelchair cushions on interface pressures at the ischial tuberosities and the sacrum of two subjects with C5 quadriplegia. In addition, interface pressures under bony prominences were assessed in the personal driving position (when the subject enters), neutral, 35 degree tilt, 45 degree tilt, and maximum recline (150 degrees). The results of this study indicate that for the two subjects evaluated, higher average interface pressures at the ischial tuberosities were obtained when using one of the three cushions under scrutiny. Furthermore, the general trend observed with both subjects is a reduction of pressure readings at the ischial tuberosities with tilt and recline positioning (especially with 45 degree tilt and 150 degree recline). The findings of this study are in keeping with previous studies which identified that individual and ongoing assessment is essential in providing the best cushion and pressure relief techniques for individuals. PMID:10462887

Pellow, T R

1999-06-01

341

PREDICTING THE RELATIVE IMPACTS OF URBAN DEVELOPMENT POLICIES AND ON-ROAD VEHICLE TECHNOLOGIES ON AIR QUALITY IN  

E-print Network

14 2.3 Air Quality Modeling Predictions 15 2.3.1 Daily Maximum 1-hour Ozone Concentrations 16 2 ON AIR QUALITY IN THE UNITED STATES: MODELING AND ANALYSIS OF A CASE STUDY IN AUSTIN, TEXAS Final Report.6 Air Quality Modeling Predictions 67 4.0 Conclusions 71 5.0 Publications/Presentations 74 6

Kockelman, Kara M.

342

Influence of entrapped air pockets on hydraulic transients in water pipelines  

Microsoft Academic Search

The pressure variations associated with a filling undulating pipeline containing an entrapped air pocket are investigated both experimentally and numerically. The influence of entrapped air on abnormal transient pressures is often ambiguous since the compressibility of the air pocket permits the liquid flow to accelerate but also partly cushions the system, with the balance of these tendencies being associated with

Ling Zhou; Deyou Liu; Byran W. Karney

2011-01-01

343

Demonstration of zinc/air fuel battery to enhance the range and mission of fleet electric vehicles: Preliminary results in the refueling of a multicell module  

SciTech Connect

We report progress in an effort to develop and demonstrate a refuelable zinc/air battery for fleet electric vehicle applications. A refuelable module consisting of twelve bipolar cells with internal flow system has been refueled at rates of nearly 4 cells per minute refueling time of 10 minutes for a 15 kW, 55 kWh battery. The module is refueled by entrainment of 0.5-mm particles in rapidly flowing electrolyte, which delivers the particles into hoppers above each cell in a parallel-flow hydraulic circuit. The concept of user-recovery is presented as an alternative to centralized service infrastructure during market entry.

Cooper, J.F.; Fleming, D.; Keene, L.; Maimoni, A.; Peterman, K.; Koopman, R.

1994-08-08

344

Membrane-Based Air Composition Control for Light-Duty Diesel Vehicles: A Benefit and Cost Assessment  

SciTech Connect

This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM{sub 2.5}). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles.

K. Stork; R. Poola

1998-10-01

345

Low-cost multi-vehicle air temperature measurements for heat load assessment in local-scale climate applications  

NASA Astrophysics Data System (ADS)

In the recent years there has been a strong interest in exploring the potential of low-cost measurement devices as alternative source of meteorological monitoring data, especially in the urban areas where high-density observations become crucial for appropriate heat load assessment. One of the simple, but efficient approaches for gathering large amount of spatial data is through mobile measurement campaigns in which the sensors are attached to driving vehicles. However, non-standardized data collecting procedure, instrument quality, their response-time and design, variable device ventilation and radiation protection influence the reliability of the gathered data. We investigate what accuracy can be expected from the data collected through low-cost mobile measurements and whether the achieved quality of the data is sufficient for validation of the state-of-the-art local-scale climate models. We tested 5 types of temperature sensors and data loggers: Maxim iButton, Lascar EL-USB-2-LCD+ and Onset HOBO UX100-003 as market available devices and self-designed solar powered Arduino-based data loggers combined with the AOSONG AM2315 and Sensirion SHT21 temperature and humidity sensors. The devices were calibrated and tested in stationary mode at the Austrian Weather Service showing accuracy between 0.1°C and 0.8°C, which was mostly within the device specification range. In mobile mode, the best response-time was found for self-designed device with Arduino-based data logger and Sensirion SHT21 sensor. However, the device lacks the mechanical robustness and should be further improved for broad-range applications. We organized 4 measurement tours: two taking place in urban environment (Vienna, Austria in July 2011 and July 2013) and two in countryside with complex terrain of Mid-Adriatic islands (Hvar and Korcula, Croatia in August 2013). Measurements were taken on clear-sky, dry and hot days. We combined multiple devices attached to bicycle and cars with different radiation protection. Duration of each measurement tour lasted approximately 2 hours covering the distances in radius of about 10-30 km, logging the air temperature and geographical positioning in intervals of 1-5 seconds. The collected data were aggregated on a 100 m horizontal resolution grid and compared with the local-scale climate modelling simulations with the urban climate model MUKLIMO3 initialized with the atmospheric conditions for a given day. Both measurement and modelling results show similar features for distinct local climate zones (built-up area, near water environment, forest, parks, agricultural area, etc). The spatial gradients in temperature can be assigned to different orographical and land use characteristics. Even if many ambiguities remain in both modelling and the measurement approach, the collected data provide useful information for local-scale heat assessment and can serve as a base to increase the model reliability, especially in areas with low data coverage.

Zuvela-Aloise, Maja; Weyss, Gernot; Aloise, Giulliano; Mifka, Boris; Löffelmann, Philemon; Hollosi, Brigitta; Nemec, Johana; Vucetic, Visnja

2014-05-01

346

Fine and landscape-scale spatial genetic structure of cushion rockjasmine, Androsace tapete (Primulaceae), across southern Qinghai-Tibetan Plateau  

Microsoft Academic Search

The cushion rockjasmine, Androsace tapete (Primulaceae), is among the angiosperms with highest altitudal distribution in the world. Cushion rockjasmine is a prominent\\u000a pioneer species in alpine deserts and alpine flowstone slope habitats up to 5,300 m on Qinghai-Tibetan Plateau. In this study,\\u000a we use inter simple sequence repeat (ISSR) markers to investigate the spatial genetic structure of A. tapete at

Yupeng Geng; Shaoqing Tang; Tsering Tashi; Zhiping Song; Guangrong Zhang; Liyan Zeng; Jiayuan Zhao; Li Wang; Jing Shi; Jiakuan Chen; Yang Zhong

2009-01-01

347

The best for the guest: high Andean nurse cushions of Azorella madreporica enhance arbuscular mycorrhizal status in associated plant species  

Microsoft Academic Search

Positive interactions between cushion plant and associated plants species in the high Andes of central Chile should also include\\u000a the effects of fungal root symbionts. We hypothesized that higher colonization by arbuscular mycorrhizal (AM) fungi exists\\u000a in cushion-associated (nursling) plants compared with conspecific individuals growing on bare ground. We assessed the AM status\\u000a of Andean plants at two sites at

M. Angélica Casanova-Katny; Gustavo Adolfo Torres-Mellado; Goetz Palfner; Lohengrin A. Cavieres

348

40 CFR 1066.415 - Vehicle operation.  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 2014-07-01 false Vehicle operation. 1066.415 Section 1066.415...AGENCY (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Preparing Vehicles and Running an Exhaust Emission Test §...

2014-07-01

349

Metal-Air Electric Vehicle Battery: Sustainable, High-Energy Density, Low-Cost Electrochemical Energy Storage – Metal-Air Ionic Liquid (MAIL) Batteries  

SciTech Connect

Broad Funding Opportunity Announcement Project: ASU is developing a new class of metal-air batteries. Metal-air batteries are promising for future generations of EVs because they use oxygen from the air as one of the battery’s main reactants, reducing the weight of the battery and freeing up more space to devote to energy storage than Li-Ion batteries. ASU technology uses Zinc as the active metal in the battery because it is more abundant and affordable than imported lithium. Metal-air batteries have long been considered impractical for EV applications because the water-based electrolytes inside would decompose the battery interior after just a few uses. Overcoming this traditional limitation, ASU’s new battery system could be both cheaper and safer than today’s Li-Ion batteries, store from 4-5 times more energy, and be recharged over 2,500 times.

None

2009-12-21

350

Using the absorbed power method to evaluate effectiveness of vibration absorption of selected seat cushions during manual wheelchair propulsion.  

PubMed

Although wheelchair users are frequently subjected to oscillatory and shock vibrations, little research has been conducted to assess the whole-body vibration exposure of wheelchair users. The purpose of this study was to determine if selected wheelchair cushions alter potentially harmful whole-body vibrations transferred to wheelchair users. Thirty-two participants, who use wheelchairs as their primary mode of mobility, contributed to this study. Four of the most commonly prescribed wheelchair cushions were selected. Participants were asked to propel their wheelchair over a simulated activities of daily living (ADL) course while acceleration and force data were recorded. A repeated measures ANOVA showed no significant differences between the different cushions for the total averaged absorbed power (p = 0.190), the 50 mm curb drop (p = 0.234), or the rumble strip (p = 0.143). A repeated measure ANOVA for the peak curb drop absorbed power revealed a significant difference in the cushions (p = 0.043). The cushions that were most effective in this testing appear to be the Invacare Pindot and the Varilite Solo. Not only did those cushions appear to have the lowest values much of the time but also they did not display the highest values. When comparing results from a similar study, absorbed power appears to be as effective in determining vibration effects in the time domain as the methods in the ISO 2631 Standard. PMID:15564117

Wolf, Erik J; Cooper, M S Rory A; DiGiovine, Carmen P; Boninger, Michael L; Guo, Songfeng

2004-11-01

351

Development of a new type of electric off-road vehicle powered by microwaves transmitted through air  

Microsoft Academic Search

Needless to say, we are now facing a critical state in the global environment, i.e. global warming. We have to change our way of thinking and our economic systems from those dependent on fossil resources to those dependent on renewable energy resources, such as solar energy. In our field of research, electric vehicles are considered the best choice for reducing

Akira Oida; Hiroshi Nakashima; Juro Miyasaka; Katsuaki Ohdoi; Hiroshi Matsumoto; Naoki Shinohara

2007-01-01

352

A Compressed Air Reduction Program  

E-print Network

Jring the "press running" mode were four tinles the "press idle" readings. Under original ecuipment design, these re>adings should have not even doubled. I NTRODL:CTI ON Compressed Air, how much does it cost us? What ways can we, U$ers of a costly energy... of compressed air on t.he manufacturi ng f1 oor are: counterba1ances, cushions, and clutch/brake components on stamping presses. In addition to determining which pif'ces of equipment are using large amounts of compressed air, B-O-C Facilities Enyineering...

Hawks, K. D.

353

Liner-on-plasma system near stagnation: Stabilizing effect of a magnetic cushion  

NASA Astrophysics Data System (ADS)

This brief communication is concerned with the adiabatic compression of a high-beta plasma by a heavy liner. Elongated cylindrical and quasi-cylindrical geometries are considered. The magnetic field in a plasma is parallel to the axis, whereas the drive field has azimuthal direction. During the liner acceleration, the most dangerous modes are axisymmetric (m = 0) modes. Near stagnation, these modes are further amplified at the inner surface, as the liner is decelerated by the isotropic pressure of a high-beta plasma. This picture, however, is not complete: due to a heat loss from the plasma core to the relatively cold liner, a zone of a strong axial magnetic field may appear between a hot, high-beta plasma and a cold liner. This magnetic cushion is backed from inside by a very high-beta plasma. The stability of such a system with respect to m = 0 modes is studied and the conclusion is drawn that the stabilizing effect of the magnetic cushion remains strong even for relatively thin cushions and moderate magnetic fields in them.

Ryutov, D. D.

2011-06-01

354

Volatile organic chemical emissions from carpet cushions: Screening measurements. Final report  

SciTech Connect

The US Consumer Product Safety Commission (CPSC) has received complaints from consumers regarding the occurrence of adverse health effects following the installation of new carpeting (Schachter, 1990). Carpet systems are suspected of emitting chemicals which may be the cause of these complaints, as well as objectionable odors. Carpets themselves have been shown to emit a variety of volatile organic compounds (VOCs). The objective of this study was to screen the representative samples of carpet cushions for emissions of individual VOCS, total VOCs (TVOC), formaldehyde, and, for the two types of polyurethane cushions, isomers of toluene diisocyanate (TDI). The measurements of VOCS, TVOC and formaldehyde were made over six-hour periods using small-volume (4-L) dynamic chambers. Sensitive gas chromatography-mass spectrometry (GC-MS) techniques were used to identify many of the VOCs emitted by the cushion samples and to obtain quantitative estimates of the emission rates of selected compounds. Separate screening measurements were conducted for TDI. The data from the screening measurements were used by the CPSC`s Health Sciences Laboratory to help design and conduct week-long measurements of emission rates of selected compounds.

Hodgson, A.T.; Phan, T.A.

1994-05-01

355

Transportation and Air Quality  

MedlinePLUS

... protects public health and the environment by regulating air pollution from motor vehicles, engines, and the fuels used ... Overview: Pollutants and Programs Information on how much air pollution, air toxics, and greenhouse gases are emitted by ...

356

The politics of consensus-building : case study of diesel vehicles and urban air pollution in South Korea  

E-print Network

Look at the three efforts to resolve public disputes over diesel passenger cars and urban air quality management in South Korea. this dissertation explores the main obstacles in nascent democracies to meeting the necessary ...

Kim, Dong-Young, Ph. D. Massachusetts Institute of Technology

2006-01-01

357

Advanced computer technology - An aspect of the Terminal Configured Vehicle program. [air transportation capacity, productivity, all-weather reliability and noise reduction improvements  

NASA Technical Reports Server (NTRS)

NASA is conducting a Terminal Configured Vehicle program to provide improvements in the air transportation system such as increased system capacity and productivity, increased all-weather reliability, and reduced noise. A typical jet transport has been equipped with highly flexible digital display and automatic control equipment to study operational techniques for conventional takeoff and landing aircraft. The present airborne computer capability of this aircraft employs a multiple computer simple redundancy concept. The next step is to proceed from this concept to a reconfigurable computer system which can degrade gracefully in the event of a failure, adjust critical computations to remaining capacity, and reorder itself, in the case of transients, to the highest order of redundancy and reliability.

Berkstresser, B. K.

1975-01-01

358

Aerothermodynamic Testing of Protuberances and Penetrations on the NASA Crew Exploration Vehicle Heat Shield in the NASA Langley 20-Inch Mach 6 Air Tunnel  

NASA Technical Reports Server (NTRS)

An experimental wind tunnel program is being conducted in support of an Agency wide effort to develop a replacement for the Space Shuttle and to support the NASA s long-term objective of returning to the moon and then on to Mars. This paper documents experimental measurements made on several scaled ceramic heat transfer models of the proposed Crew Exploration Vehicle. Global heat transfer images and heat transfer distributions obtained using phosphor thermography were used to infer interference heating on the Crew Exploration Vehicle Cycle 1 heat shield from local protuberances and penetrations for both laminar and turbulent heating conditions. Test parametrics included free stream Reynolds numbers of 1.0x10(exp 6)/ft to 7.25x10(exp 6)/ft in Mach 6 air at a fixed angle-of-attack. Single arrays of discrete boundary layer trips were used to trip the boundary layer approaching the protuberances/penetrations to a turbulent state. Also, the effects of three compression pad diameters, two radial locations of compression pad/tension tie location, compression pad geometry, and rotational position of compression pad/tension tie were examined. The experimental data highlighted in this paper are to be used to validate CFD tools that will be used to generate the flight aerothermodynamic database. Heat transfer measurements will also assist in the determination of the most appropriate engineering methods that will be used to assess local flight environments associated with protuberances/penetrations of the CEV thermal protection system.

Liechty, Derek S.

2008-01-01

359

C.E. Schwartz, T.G. Bryant. J.H. Cosgrove, G.B. Morse, andJ.K. Noonan A Radar for Unmanned Air Vehicles  

E-print Network

Overtheyears airborneradars haveproven theirvalue aswide-area, nearly all-weather surveillance tools. Typically, airborne radars are large systems mounted in manned aircraft. Lincoln Laboratory, however, has built a very capable radar system that is compact and lightweight; the radar has been integrated into an unmanned air vehicle (UAV). The work is sponsored by the Army's Harry Diamond Laboratories and the Defense Advanced Research Projects Agency (DARPA). A significant component of the radar is a Lincoln Laboratory-designed programmable processor that performs moving-target detection on board the UAV. The onboard processing permits the use of a UAV data link that transmits kilobits per second of moving-target reports instead of tens of megabits per second of raw radar data. The system-the airborne portion ofwhich weighs only 110 lb-detects and tracks moving vehicles such as tanks, trucks, and low-flying helicopters out to a range of 15 km, and classifies them at shorter ranges. Unmanned airvehicles (UAV) have proven to be useful for observing activity on the ground

unknown authors

360

An investigation of drag reduction for tractor trailer vehicles with air deflector and boattail. [wind tunnel tests  

NASA Technical Reports Server (NTRS)

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.

Muirhead, V. U.

1981-01-01

361

Effects of floral neighborhood on seed set and degree of outbreeding in a high-alpine cushion plant.  

PubMed

Plants flowering together may influence each other's pollination and fecundity over a range of physical distances. Their effects on one another can be competitive, neutral, or facilitative. We manipulated the floral neighborhood of the high-alpine cushion plant Eritrichium nanum in the Swiss Alps and measured the effects of co-flowering neighbors on both the number of seeds produced and the degree of inbreeding and outbreeding in the offspring, as deduced from nuclear microsatellite markers. Seed set of E. nanum did not vary significantly with the presence or absence of two Saxifraga species growing as near neighbors, but it was higher in E. nanum cushions growing at low conspecific density than in those growing at high density. In addition, floral neighborhood had no detectable effect on the degree of selfing of E. nanum, but seeds from cushions growing at low conspecific density were more highly outbred than seeds from cushions at high density. Thus, there was no evidence of either competition or facilitation between E. nanum and Saxifraga spp. as mediated by pollinators at the spatial scale of our experimental manipulation. In contrast, the greater fecundity of E. nanum cushions at low density was consistent with reduced intraspecific competition for pollinators and might also represent a beneficial effect of highly outbred seeds as brought about by more long-distance pollinator flights under low-density conditions. PMID:21484399

Wirth, Lea R; Waser, Nickolas M; Graf, René; Gugerli, Felix; Landergott, Urs; Erhardt, Andreas; Linder, Hans Peter; Holderegger, Rolf

2011-10-01

362

N-Acetyl-S-(n-Propyl)-L-Cysteine in Urine from Workers Exposed to 1-Bromopropane in Foam Cushion Spray Adhesives  

PubMed Central

1-Bromopropane (1-BP) has been marketed as an alternative for ozone depleting and other solvents; it is used in aerosol products, adhesives, metal, precision, and electronics cleaning solvents. Mechanisms of toxicity of 1-BP are not fully understood, but it may be a neurological and reproductive toxicant. Sparse exposure information prompted this study using 1-BP air sampling and urinary metabolites. Mercapturic acid conjugates are excreted in urine from 1-BP metabolism involving debromination. Research objectives were to evaluate the utility of urinary N-acetyl-S-(n-propyl)-L-cysteine (AcPrCys) for assessing exposure to 1-BP and compare it to urinary bromide [Br(?)] previously reported for these workers. Forty-eight-hour urine specimens were obtained from 30 workers at two factories where 1-BP spray adhesives were used to construct polyurethane foam seat cushions. Urine specimens were also obtained from 21 unexposed control subjects. All the workers' urine was collected into composite samples representing three time intervals: at work, after work but before bedtime, and upon awakening. Time-weighted average (TWA) geometric mean breathing zone concentrations were 92.4 and 10.5 p.p.m. for spraying and non-spraying jobs, respectively. Urinary AcPrCys showed the same trend as TWA exposures to 1-BP: higher levels were observed for sprayers. Associations of AcPrCys concentrations, adjusted for creatinine, with 1-BP TWA exposure were statistically significant for both sprayers (P < 0.05) and non-sprayers (P < 0.01). Spearman correlation coefficients for AcPrCys and Br(?) analyses determined from the same urine specimens were highly correlated (P < 0.0001). This study confirms that urinary AcPrCys is an important 1-BP metabolite and an effective biomarker for highly exposed foam cushion workers. PMID:19706636

Hanley, Kevin W.; Petersen, Martin R.; Cheever, Kenneth L.; Luo, Lian

2009-01-01

363

Analytical characterization of some components used in cellular silicon cushions: round-robin results  

SciTech Connect

The analytical characterization of a polysiloxane gum, General Electric's SE-54, has been completed in a round-robin fashion between Lawrence Livermore National Laboratory and Bendix Corporation (Kansas City Division). Three lots of gum were analyzed for the following chemical and physical properties: volatiles, molecular weight, weight percent vinyl and weight percent phenyl. The net result was specifications and procedures to be used for material acceptance at Bendix. In addition, a preliminary characterization has been completed of the silica filler used in conjunction with the polysiloxane gum to make cellular silicone cushions.

Catalano, E.; Clarkson, J.E.; Cupps, J.

1983-01-01

364

Cushioned centrifugation of stallion semen: factors impacting equine sperm recovery rate and quality  

E-print Network

osmolarity of 170 + 15 mOsm [72]. Two other high-density cushion fluids have recently become available commercially and were developed to be isotonic (~ 300 mOsm) to protect sperm during high-speed centrifugation. These products, Eqcellsire® Component... to be both metabolically inert and non toxic to cells [72]. The high density (1.320 + .001 g/mL) of this medium prevents interaction with mammalian cells [72] when appropriately layered in a centrifugation tube. This medium is hypotonic, with a reported...

Waite, Jessica Arlene

2008-10-10

365

Cushioned centrifugation of stallion semen: factors impacting equine sperm recovery rate and quality  

E-print Network

osmolarity of 170 + 15 mOsm [72]. Two other high-density cushion fluids have recently become available commercially and were developed to be isotonic (~ 300 mOsm) to protect sperm during high-speed centrifugation. These products, Eqcellsire? Component... to be both metabolically inert and non toxic to cells [72]. The high density (1.320 + .001 g/mL) of this medium prevents interaction with mammalian cells [72] when appropriately layered in a centrifugation tube. This medium is hypotonic, with a reported...

Waite, Jessica Arlene

2009-05-15

366

Measurement-systems evaluation for the Support Cushion Life Test Program  

SciTech Connect

A series of experiments were conducted to determine accuracy and precision (repeatability) capabilities of the measurement systems being used in the Support Cushion Life Test Program. Also, the experiments were intended to expose any system weaknesses, and provide baseline data for continuous monitoring of the measurement systems during the Life Test Program. Systems evaluated were the Instron Tension/Compression Tester System and the Kaman Eddy Current Thickness Measuring System. The experiments were conducted such that they evaluated all primary functions of the systems (i.e., multiple independent functions for the Instron). Interpretation of the experimental analyses indicated that both systems were acceptable for use in the Life Test Program.

Rodin, L.W.; Jasper, S.E.; Myers, J.C.

1982-02-01

367

43 CFR 36.2 - Definitions.  

Code of Federal Regulations, 2014 CFR

...periodically marked, brushed, or broken for off-road vehicles are excluded. (j) Incident to its...rights-of-way for snowmachines, air cushion vehicles and other all-terrain vehicles. (7) Roads, highways, railroads, tunnels,...

2014-10-01

368

43 CFR 36.2 - Definitions.  

Code of Federal Regulations, 2010 CFR

...periodically marked, brushed, or broken for off-road vehicles are excluded. (j) Incident to its...rights-of-way for snowmachines, air cushion vehicles and other all-terrain vehicles. (7) Roads, highways, railroads, tunnels,...

2010-10-01

369

43 CFR 36.2 - Definitions.  

Code of Federal Regulations, 2011 CFR

...periodically marked, brushed, or broken for off-road vehicles are excluded. (j) Incident to its...rights-of-way for snowmachines, air cushion vehicles and other all-terrain vehicles. (7) Roads, highways, railroads, tunnels,...

2011-10-01

370

43 CFR 36.2 - Definitions.  

Code of Federal Regulations, 2012 CFR

...periodically marked, brushed, or broken for off-road vehicles are excluded. (j) Incident to its...rights-of-way for snowmachines, air cushion vehicles and other all-terrain vehicles. (7) Roads, highways, railroads, tunnels,...

2012-10-01

371

43 CFR 36.2 - Definitions.  

Code of Federal Regulations, 2013 CFR

...periodically marked, brushed, or broken for off-road vehicles are excluded. (j) Incident to its...rights-of-way for snowmachines, air cushion vehicles and other all-terrain vehicles. (7) Roads, highways, railroads, tunnels,...

2013-10-01

372

Whole-body vibration during manual wheelchair propulsion with selected seat cushions and back supports.  

PubMed

Although the exposure to whole-body vibrations (WBV) has been shown to be detrimental to seated humans, the effects of wheelchairs and seating systems on the transmission of vibration to an individual have not been thoroughly examined. The purpose of this study was to determine if the selected wheelchair seat cushions and back supports minimize the transmission of vibrations. Thirty-two wheelchair users traversed an activities of daily living course three times using 16 randomly selected seating systems as well as their own. Vibrations were measured using triaxial accelerometers at the seat and participant's head. The weighted fore-to-aft (Tx), vertical (Tz), and resultant (Tr) transmissibility based on the vibrational-dose-value (VDV) were used to determine if differences existed among the four seat cushions and back supports. The obstacles that seem to have the largest effect on the transmission of WBV are the single event shocks and the repeated event shocks. Comparisons between the individuals own seating system and the tested seating systems suggest that the individuals are not using the most appropriate seating system in terms of the reduction of vibration transmission. PMID:14518796

DiGiovine, Carmen P; Cooper, Rory A; Fitzgerald, Shirley G; Boninger, Michael L; Wolf, Erik J; Guo, Songfeng

2003-09-01

373

Modal analysis of an artificial wing mimicking an Allomyrina dichotoma beetle's hind wing for flapping-wing micro air vehicles by noncontact measurement techniques  

NASA Astrophysics Data System (ADS)

Recently, the development of flapping-wing micro air vehicles (FW-MAV) for operation in extreme environmental conditions has demanded properly designed, biologically inspired wings that can produce enough lift force to keep the vehicles aloft. The structural analysis of an artificial wing is carried out in the design of an FW-MAV. In this study, the dynamic characteristics of an artificial wing mimicking an Allomyrina dichotoma beetle's hind wing were investigated by a non-contact measurement method. The natural frequencies, mode shapes, and damping ratios of the first three basic vibration modes in the operating frequency range were determined using a Bruel & Kjaer (B&K) fast Fourier transform analyzer, along with a laser sensor. The laser sensor was used to obtain the displacement history of the marked points on the wing to calculate the frequency response function. To confirm the results, a three-dimensional digital image correlation (3D-DIC) method, as well as high speed digital cameras, were employed to construct the mode shapes of the wing when it was vibrated at a pre-determined natural frequency. The mode shapes by the DIC method showed good agreement with those by the laser displacement sensor. These results provide a method for the modal analysis of a light weight structure like an insect wing as well as for the construction of the mode shapes using DIC. The high speed 3D-DIC method, used successfully in mode shape measurements, can also be used to study the wing deformation of an insect during flight, which is challenging in an insect study.

Ha, Ngoc San; Jin, Tailie; Goo, Nam Seo

2013-05-01

374

Cushions of Thylacospermum caespitosum (Caryophyllaceae) do not facilitate other plants under extreme altitude and dry conditions in the north-west Himalayas  

PubMed Central

Background Cushion plants are commonly considered as keystone nurse species that ameliorate the harsh conditions they inhabit in alpine ecosystems, thus facilitating other species and increasing alpine plant biodiversity. A literature search resulted in 25 key studies showing overwhelming facilitative effects of different cushion plants and hypothesizing greater facilitation with increased environmental severity (i.e. higher altitude and/or lower rainfall). At the same time, emerging ecological theory alongside the cushion-specific literature suggests that facilitation might not always occur under extreme environmental conditions, and especially under high altitude and dryness. Methods To assess these hypotheses, possible nursing effects of Thylacospermum caespitosum (Caryophyllaceae) were examined at extremely high altitude (5900 m a.s.l.) and in dry conditions (precipitation <100 mm year?1) in Eastern Ladakh, Trans-Himalaya. This is, by far, the highest site, and the second driest, at which the effects of cushions have been studied so far. Key Results In accordance with the theoretical predictions, no nursing effects of T. caespitosum on other alpine plants were detected. The number and abundance of species were greater outside cushions than within and on the edge of cushions. None of the 13 species detected was positively associated with cushions, while nine of them were negatively associated. Plant diversity increased with the size of the area sampled outside cushions, but no species–area relationship was found within cushions. Conclusions The results support the emerging theoretical prediction of restricted facilitative effects under extreme combinations of cold and dryness, integrating these ideas in the context of the ecology of cushion plants. This evidence suggests that cases of missing strong facilitation are likely to be found in other extreme alpine conditions. PMID:21813564

de Bello, Francesco; Doležal, Ji?í; Dvorský, Miroslav; Chlumská, Zuzana; ?eháková, Klára; Klimešová, Jitka; Klimeš, Leoš

2011-01-01

375

The morphological characterization of the forewing of the Manduca sexta species for the application of biomimetic flapping wing micro air vehicles.  

PubMed

To properly model the structural dynamics of the forewing of the Manduca sexta species, it is critical that the material and structural properties of the biological specimen be understood. This paper presents the results of a morphological study that has been conducted to identify the material and structural properties of a sample of male and female Manduca sexta specimens. The average mass, area, shape, size and camber of the wing were evaluated using novel measurement techniques. Further emphasis is placed on studying the critical substructures of the wing: venation and membrane. The venation cross section is measured using detailed pathological techniques over the entire venation of the wing. The elastic modulus of the leading edge veins is experimentally determined using advanced non-contact structural dynamic techniques. The membrane elastic modulus is randomly sampled over the entire wing to determine global material properties for the membrane using nanoindentation. The data gathered from this morphological study form the basis for the replication of future finite element structural models and engineered biomimetic wings for use with flapping wing micro air vehicles. PMID:23093001

O'Hara, R P; Palazotto, A N

2012-12-01

376

The Vehicle Ecosystem  

NASA Astrophysics Data System (ADS)

Ubiquitous computing in the vehicle industry has primarily focused on sensor data serving different ubiquitous on-board services (e.g., crash detection, antilock brake systems, or air conditioning). These services mainly address vehicle drivers while driving. However, in view of the role of vehicles in today's society, it goes without saying that vehicles relate to more than just the driver or occupants; they are part of a larger ecosystem, including traffic participants, authorities, customers and the like. To serve the ecosystem with ubiquitous services based on vehicle sensor data, there is a need for an open information infrastructure that enables service development close to the customer. This paper presents results from a research project on designing such an infrastructure at a major European vehicle manufacturer. Our empirical data shows how the vehicle manufacturer's conceptualization of services disagrees with the needs of vehicle stakeholders in a more comprehensive vehicle ecosystem. In light of this, we discuss the effect on information infrastructure design and introduce the distinction between information infrastructure as product feature and service facilitator. In a more general way, we highlight the importance of information infrastructure to contextualize the vehicle as part of a larger ecosystem and thus support open innovation.

Kuschel, Jonas

377

Direct compression of cushion-layered ethyl cellulose-coated extended release pellets into rapidly disintegrating tablets without changes in the release profile.  

PubMed

The aim of this study was to develop and optimize a segregation-free ethyl cellulose-coated extended release multiparticulate formulation to be compressed into tablets without affecting the drug release. Standard tableting excipients (e.g., microcrystalline cellulose, lactose or sorbitol) were layered onto ethyl cellulose-coated propranolol hydrochloride pellets to form a cushion layer in order to eliminate segregation problems normally resulting from particle size difference between coated pellets and excipient powders and second to protect the integrity of the brittle ethyl cellulose coating during compression. The disintegration behavior of the tablets depended strongly on the composition of the cushion layer. Rapid tablet disintegration was obtained with microcrystalline cellulose and the disintegrant sodium croscarmellose. However, the drug release from these cushion-layered pellets still increased upon compression. Incorporation of a glidant into the cushion layer or between the cushion layer and the ethyl cellulose coating reduced the compression effect on drug release markedly. Glidant-containing formulations showed a delayed deformation and damage of the ethyl cellulose-coated pellet upon mechanical stress. In summary, cushion layer based on microcrystalline cellulose facilitated segregation-free compression of a highly compression-sensitive extended release ethyl cellulose-coated pellets into fast-disintegrating and hard tablets without compromising the release properties of the multiparticulates. Directly compressible cushion-layered pellets protected the pellet coating significantly better from damages during tabletting when compared to the conventional compression of blends of coated pellets and excipient powders. PMID:23892153

Hosseini, Armin; Körber, Martin; Bodmeier, Roland

2013-12-01

378

40 CFR 86.1828-01 - Emission data vehicle selection.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-01...

2012-07-01

379

40 CFR 86.1828-01 - Emission data vehicle selection.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-01...

2010-07-01

380

40 CFR 86.1807-07 - Vehicle labeling.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1807-07...

2012-07-01

381

40 CFR 86.1807-07 - Vehicle labeling.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1807-07...

2010-07-01

382

40 CFR 86.1828-01 - Emission data vehicle selection.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-01...

2013-07-01

383

40 CFR 86.1828-10 - Emission data vehicle selection.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-10...

2010-07-01

384

40 CFR 86.1807-07 - Vehicle labeling.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1807-07...

2011-07-01

385

40 CFR 86.1828-10 - Emission data vehicle selection.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-10...

2012-07-01

386

40 CFR 86.1822-01 - Durability data vehicle selection.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1822-01...

2012-07-01

387

40 CFR 86.1822-01 - Durability data vehicle selection.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1822-01...

2013-07-01

388

40 CFR 86.1822-01 - Durability data vehicle selection.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1822-01...

2010-07-01

389

40 CFR 86.1828-01 - Emission data vehicle selection.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-01...

2011-07-01

390

40 CFR 86.1828-10 - Emission data vehicle selection.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-10...

2013-07-01

391

40 CFR 86.1828-10 - Emission data vehicle selection.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1828-10...

2011-07-01

392

40 CFR 86.1822-01 - Durability data vehicle selection.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1822-01...

2011-07-01

393

5-Star Safety Ratings: 2011-Newer Vehicles  

MedlinePLUS

5-Star Safety Ratings 2011-Newer Vehicles 1990-2010 Vehicles Air Bags Child Safety at Parents Central Resources Rollover ... to the most frequently asked questions about 5-Star Safety Ratings. Shop Smart for a Safer Car, ...

394

40 CFR 88.306-94 - Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle. 88.306-94 Section 88.306-94... AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program §...

2013-07-01

395

40 CFR 88.306-94 - Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle. 88.306-94 Section 88.306-94... AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program §...

2012-07-01

396

40 CFR 88.306-94 - Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle.  

Code of Federal Regulations, 2014 CFR

...2013-07-01 true Requirements for a converted vehicle to qualify as a clean-fuel fleet vehicle. 88.306-94 Section 88.306-94... AIR PROGRAMS (CONTINUED) CLEAN-FUEL VEHICLES Clean-Fuel Fleet Program §...

2014-07-01

397

40 CFR 86.1842-01 - Addition of a vehicle after certification; and changes to a vehicle covered by certification.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1842-01...

2011-07-01

398

40 CFR 86.1842-01 - Addition of a vehicle after certification; and changes to a vehicle covered by certification.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1842-01...

2013-07-01

399

40 CFR 86.1842-01 - Addition of a vehicle after certification; and changes to a vehicle covered by certification.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1842-01...

2010-07-01

400

40 CFR 86.1842-01 - Addition of a vehicle after certification; and changes to a vehicle covered by certification.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1842-01...

2012-07-01

401

Lifting Body Flight Vehicles  

NASA Technical Reports Server (NTRS)

NASA has a technology program in place to build the X-33 test vehicle and then the full sized Reusable Launch Vehicle, VentureStar. VentureStar is a Lifting Body (LB) flight vehicle which will carry our future payloads into orbit, and will do so at a much reduced cost. There were three design contenders for the new Reusable Launch Vehicle: a Winged Vehicle, a Vertical Lander, and the Lifting Body(LB). The LB design won the competition. A LB vehicle has no wings and derives its lift solely from the shape of its body, and has the unique advantages of superior volumetric efficiency, better aerodynamic efficiency at high angles-of-attack and hypersonic speeds, and reduced thermal protection system weight. Classically, in a ballistic vehicle, drag has been employed to control the level of deceleration in reentry. In the LB, lift enables the vehicle to decelerate at higher altitudes for the same velocity and defines the reentry corridor which includes a greater cross range. This paper outlines our LB heritage which was utilized in the design of the new Reusable Launch Vehicle, VentureStar. NASA and the U.S. Air Force have a rich heritage of LB vehicle design and flight experience. Eight LB's were built and over 225 LB test flights were conducted through 1975 in the initial LB Program. Three LB series were most significant in the advancement of today's LB technology: the M2-F; HL-1O; and X-24 series. The M2-F series was designed by NASA Ames Research Center, the HL-10 series by NASA Langley Research Center, and the X-24 series by the Air Force. LB vehicles are alive again today.

Barret, Chris

1998-01-01

402

Endocardial Cushion Morphogenesis and Coronary Vessel Development Require Chicken Ovalbumin Upstream Promoter-Transcription Factor II  

PubMed Central

Objective Septal defects and coronary vessel anomalies are common congenital heart defects, yet their ontogeny and the underlying genetic mechanisms are not well understood. Here, we investigated the role of chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII, NR2F2) in cardiac organogenesis. Methods and Results We analyzed embryos deficient in COUP-TFII and observed a spectrum of cardiac defects, including atrioventricular septal defect, thin-walled myocardium, and abnormal coronary morphogenesis. We show by expression analysis that COUP-TFII is expressed in the endocardium and the epicardium but not in the myocardium of the ventricle. Using endothelial-specific COUP-TFII mutants and molecular approaches, we show that COUP-TFII deficiency resulted in endocardial cushion hypoplasia. This was attributed to the reduced growth and survival of atrioventricular cushion mesenchymal cells and defective epithelial-mesenchymal transformation (EMT) in the underlying endocardium. In addition, the endocardial EMT defect was accompanied by downregulation of Snai1, one of the master regulators of EMT, and upregulation of vascular endothelial-cadherin. Furthermore, we show that although COUP-TFII does not play a major role in the formation of epicardial cell cysts, it is critically important for the formation of epicardium. Ablation of COUP-TFII impairs epicardial EMT and coronary plexus formation. Conclusion Our results reveal that COUP-TFII plays cell-autonomous roles in the endocardium and the epicardium for endocardial and epicardial EMT, which are required for proper valve and coronary vessel formation during heart development. PMID:22962329

Lin, Fu-Jung; You, Li-Ru; Yu, Cheng-Tai; Hsu, Wen-Hsin; Tsai, Ming-Jer; Tsai, Sophia Y.

2013-01-01

403

Traffic-related air pollution in the community of San Ysidro, CA, in relation to northbound vehicle wait times at the US-Mexico border Port of Entry  

NASA Astrophysics Data System (ADS)

The San Diego/Tijuana US-Mexico border crossing at the San Ysidro Port of Entry (POE) is the world's busiest international land border crossing (GSA, 2013). San Ysidro, California, is the US community immediately adjacent to the border crossing. More than 90% of San Ysidro residents are Hispanic, and the average household income is less than 60% of the San Diego regional average. This study investigated the San Ysidro POE as a source of traffic-related air pollutants in San Ysidro, especially in relation to wind direction and northbound vehicle wait times. The pollutants ultrafine particulate matter (UFP), black carbon (BC), and particulate matter <2.5 ?m in diameter (PM2.5) were periodically sampled through the course of 2010 at four rooftop locations: one commercial establishment near the POE, two elementary schools in San Ysidro, and a coastal estuary reference site. Weather data from two nearby sites and northbound border wait times were also collected. Results indicate consistently higher daytime BC and UFP concentrations at the measurement sites near the POE. Pollution concentrations were higher during low wind speeds or when wind was blowing from the POE towards San Ysidro. In February, March and November measurements, black carbon pollution appeared to be significantly positively associated with the POE northbound wait times when the wind direction was blowing from the POE towards San Ysidro or during low wind speeds, but not when the wind direction was from the west/northwest towards the POE. This pilot study is the first to investigate the potential effect of the POE, especially the long northbound traffic delays, on the nearby community of San Ysidro. Disparities in traffic exposures are an environmental justice issue and this should be taken into account during planning and operation of POEs.

Quintana, Penelope J. E.; Dumbauld, Jill J.; Garnica, Lynelle; Chowdhury, M. Zohir; Velascosoltero, José; Mota-Raigoza, Arturo; Flores, David; Rodríguez, Edgar; Panagon, Nicolas; Gamble, Jamison; Irby, Travis; Tran, Cuong; Elder, John; Galaviz, Vanessa E.; Hoffman, Lisa; Zavala, Miguel; Molina, Luisa T.

2014-05-01

404

40 CFR 1066.105 - Ambient controls and vehicle cooling fans.  

Code of Federal Regulations, 2014 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Equipment...the vehicle is exposed, which includes intake air; other than the intake air, humidity does not affect emissions, so...

2014-07-01

405

RECONSTRUCTING THE ORIGINS OF HIGH-ALPINE NICHES AND CUSHION LIFE FORM IN THE GENUS ANDROSACE S.L. (PRIMULACEAE)  

PubMed Central

Relatively, few species have been able to colonize extremely cold alpine environments. We investigate the role played by the cushion life form in the evolution of climatic niches in the plant genus Androsace s.l., which spreads across the mountain ranges of the Northern Hemisphere. Using robust methods that account for phylogenetic uncertainty, intraspecific variability of climatic requirements and different life-history evolution scenarios, we show that climatic niches of Androsace s.l. exhibit low phylogenetic signal and that they evolved relatively recently and punctually. Models of niche evolution fitted onto phylogenies show that the cushion life form has been a key innovation providing the opportunity to occupy extremely cold environments, thus contributing to rapid climatic niche diversification in the genus Androsace s.l. We then propose a plausible scenario for the adaptation of plants to alpine habitats. PMID:22486702

Boucher, Florian C.; Thuiller, Wilfried; Roquet, Cristina; Douzet, Rolland; Aubert, Serge; Alvarez, Nadir; Lavergne, Sébastien

2014-01-01

406

Thrombus Formation on the Tricuspid Valve After De Vega’s Annuloplasty and Repair of Endocardial Cushion Defect  

PubMed Central

Endocardial cushion defect (ECD) can be partial (with two distinct valves) or complete (only one atrioventricular valve), and surgical therapy is usually required. The optimal surgical technique is controversial but De Vega’s annuloplasty is widely performed. Tricuspid valve thrombosis are rarely seen after surgery. We present a 39-year-old male patient with tricuspid valve thrombosis after De Vega’s annuloplasty without the use of a ring. PMID:25320670

Efe, Süleyman Ça?an; Unkun, Tuba; ?zci, Servet; Çap, Murat; Bakal, Ruken Bengi; Acar, Rezzan Deniz; Geçmen, Çetin; Erdo?an, Emrah; Özdemir, Nihal

2014-01-01

407

Effects of floral neighborhood on seed set and degree of outbreeding in a high-alpine cushion plant  

Microsoft Academic Search

Plants flowering together may influence each other’s pollination and fecundity over a range of physical distances. Their effects\\u000a on one another can be competitive, neutral, or facilitative. We manipulated the floral neighborhood of the high-alpine cushion\\u000a plant Eritrichium nanum in the Swiss Alps and measured the effects of co-flowering neighbors on both the number of seeds produced and the degree

Lea R. WirthNickolas; Nickolas M. Waser; René Graf; Felix Gugerli; Urs Landergott; Andreas Erhardt; Hans Peter Linder; Rolf Holderegger

408

THE EFFECT OF KNEE POSTURES AND CUSHIONS IN THE LOAD TRANSMISSION OF IMPACT LOADING - AN IN VITRO BIOMECHANICAL PORCINE MODEL  

Microsoft Academic Search

Degenerative drteoarttiritls is dU('cushions and flexed posture are two important factors to reduce the impact force; however, no

JAW-LIN WANG; YEN-LIN LEE

2004-01-01

409

Spatial Transcriptional Profile of the Chick and Mouse Endocardial Cushions Identify Novel Regulators of Endocardial EMT in vitro  

PubMed Central

Valvular Interstitial Cells (VICs) are a common substrate for congenital and adult heart disease yet the signaling mechanisms governing their formation during early valvulogenesis are incompletely understood. We developed an unbiased strategy to identify genes important in endocardial epithelial-to-mesenchymal transformation (EMT) using a spatial transcriptional profile. Endocardial cells overlaying the cushions of the atrioventricular canal (AVC) and outflow tract (OFT) undergo an EMT to yield VICs. RNA sequencing (RNA-seq) analysis of gene expression between AVC, OFT, and ventricles (VEN) isolated from chick and mouse embryos at comparable stages of development (chick HH18; mouse E11.0) was performed. EMT occurs in the AVC and OFT cushions, but not VEN at this time. 198 genes in the chick (n=1) and 105 genes in the mouse (n=2) were enriched 2-fold in the cushions. Gene regulatory networks (GRN) generated from cushion-enriched gene lists confirmed TGF? as a nodal point and identified NF-?B as a potential node. To reveal previously unrecognized regulators of EMT four candidate genes, Hapln1, Id1, Foxp2, and Meis2, and a candidate pathway, NF-?B, were selected. In vivo spatial expression of each gene was confirmed by in situ hybridization and a functional role for each in endocardial EMT was determined by siRNA knockdown in a collagen gel assay. Our spatial-transcriptional profiling strategy yielded gene lists which reflected the known biology of the system. Further analysis accurately identified and validated previously unrecognized novel candidate genes and the NF-?B pathway as regulators of endocardial cell EMT in vitro. PMID:23557753

DeLaughter, Daniel M.; Christodoulou, Danos C.; Robinson, Jamille Y.; Seidman, Christine E.; Baldwin, H. Scott; Seidman, J. G.; Barnett, Joey V.

2013-01-01

410

Measurement and modelling of x-direction apparent mass of the seated human body–cushioned seat system  

Microsoft Academic Search

For modelling purposes and for evaluation of driver's seat performance in the vertical direction various mechano-mathematical models of the seated human body have been developed and standardized by the ISO. No such models exist hitherto for human body sitting in an upright position in a cushioned seat upper part, used in industrial environment, where the fore-and-aft vibrations play an important

George Juraj Stein; Peter Mú?ka; Rudolf Chmúrny; Barbara Hinz; Ralph Blüthner

2007-01-01

411

Sensitivity of urban airshed model results for test fuels to uncertainties in light-duty vehicle and biogenic emissions and alternative chemical mechanisms—Auto/oil air quality improvement research program  

NASA Astrophysics Data System (ADS)

Three sources of uncertainty in the air quality modeling performed for the Auto/Oil Air Quality Improvement: Research Program, Phase I, were investigated to assess their impact on predicted ozone for test fuels in Los Angeles in year 2010. First, quadrupling the estimated total organic gas (TOG) and tripling the CO emissions from light-duty gasoline vehicles in the air quality model increases the predicted peak ozone, as expected. The percent increase in peak ozone for the test fuels, about 25% of total ozone, is essentially the same as the percent increase in TOG emissions, about 25% of the total emissions from all sources. However, there is no important effect on the ranking of the test fuels from lowest to highest in predicted ozone formation. Second, replacing the original biogenic emission inventory with an alternative inventory having substantially lower biogenic emissions reduces the predicted peak ozone. The percent decrease in peak ozone, about 6% of total ozone, is considerably less than the percent decrease in TOG emissions, about 34% of total emissions. Fuel rankings are unchanged except for a reversal of two test gasolines in the ranking based on peak ozone. However, this reversal is not found in fuel rankings based on other measures of ozone formation. Third, replacing the Carbon Bond Mechanism version IV (CBM-IV) in the air quality model with an alternative representation of atmospheric chemistry, the Statewide Air Pollution Research Center (SAPRC) mechanism, increases the peak ozone by about 9%. There are also important changes in fuel rankings. For one research test gasoline, the contribution of light-duty gasoline vehicles to ozone is similar with both chemical mechanisms, but for another test gasoline that gives the lowest ozone with the CBM-IV, the contribution of light-duty gasoline vehicles to ozone is substantially higher with the SAPRC mechanism. With the CBM-IV mechanism, the most promising of the test gasolines studied has lower predicted ozone than any of the cases representing use of methanol fuels in prototype, flexible/variable fuel vehicles. With the SAPRC mechanism, the most promising test gasoline studied has lower predicted ozone than one methanol case and higher ozone than the other methanol case. These changes in fuel rankings are probably due to known differences in the reactivity of toluene and formaldehyde in the two mechanisms.

Chock, David P.; Yarwood, Greg; Dunker, Alan M.; Morris, Ralph E.; Pollack, Alison K.; Schleyer, Charles H.

412

DBD Plasma Actuators for Flow Control in Air Vehicles and Jet Engines - Simulation of Flight Conditions in Test Chambers by Density Matching  

NASA Technical Reports Server (NTRS)

Dielectric Barrier Discharge (DBD) Plasma actuators for active flow control in aircraft and jet engines need to be tested in the laboratory to characterize their performance at flight operating conditions. DBD plasma actuators generate a wall-jet electronically by creating weakly ionized plasma, therefore their performance is affected by gas discharge properties, which, in turn, depend on the pressure and temperature at the actuator placement location. Characterization of actuators is initially performed in a laboratory chamber without external flow. The pressure and temperature at the actuator flight operation conditions need to be simultaneously set in the chamber. A simplified approach is desired. It is assumed that the plasma discharge depends only on the gas density, while other temperature effects are assumed to be negligible. Therefore, tests can be performed at room temperature with chamber pressure set to yield the same density as in operating flight conditions. The needed chamber pressures are shown for altitude flight of an air vehicle and for jet engines at sea-level takeoff and altitude cruise conditions. Atmospheric flight conditions are calculated from standard atmosphere with and without shock waves. The engine data was obtained from four generic engine models; 300-, 150-, and 50-passenger (PAX) aircraft engines, and a military jet-fighter engine. The static and total pressure, temperature, and density distributions along the engine were calculated for sea-level takeoff and for altitude cruise conditions. The corresponding chamber pressures needed to test the actuators were calculated. The results show that, to simulate engine component flows at in-flight conditions, plasma actuator should be tested over a wide range of pressures. For the four model engines the range is from 12.4 to 0.03 atm, depending on the placement of the actuator in the engine. For example, if a DBD plasma actuator is to be placed at the compressor exit of a 300 PAX engine, it has to be tested at 12.4 atm for takeoff, and 6 atm for cruise conditions. If it is to be placed at the low-pressure turbine, it has to be tested at 0.5 and 0.2 atm, respectively. These results have implications for the feasibility and design of DBD plasma actuators for jet engine flow control applications. In addition, the distributions of unit Reynolds number, Mach number, and velocity along the engine are provided. The engine models are non-proprietary and this information can be used for evaluation of other types of actuators and for other purposes.

Ashpis, David E.; Thurman, Douglas R.

2011-01-01

413

Vehicle Cabin Atmosphere Monitor  

NASA Technical Reports Server (NTRS)

Vehicle Cabin Atmosphere Monitor (VCAM) identifies gases that are present in minute quantities in the International Space Station (ISS) breathing air that could harm the crew s health. If successful, instruments like VCAM could accompany crewmembers during long-duration exploration missions to the Moon or traveling to Mars.

Chutjian, Ara; Darrach, Muray

2007-01-01

414

Suspension for vehicle  

Microsoft Academic Search

A suspension is described for a vehicle comprising: a shock absorber capable of adjusting the damping force for damping vibration given from a wheel; a bushing interposed between the shock absorber and a car body and capable of adjusting the spring constant and damping force; an air spring capable of adjusting the spring constant for damping the vibration given from

Buma

1987-01-01

415

Personnel emergency carrier vehicle  

NASA Technical Reports Server (NTRS)

A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

Owens, Lester J. (inventor); Fedor, Otto H. (inventor)

1987-01-01

416

Endothelial SUR-8 acts in an ERK-independent pathway during atrioventricular cushion development.  

PubMed

SUR-8, a conserved leucine-rich repeats protein, was first identified as a positive regulator of Ras pathway in Caenorhabditis elegans. Biochemical studies indicated that SUR-8 interacts with Ras and Raf, leading to the elevated ERK activity. However, the physiological role of SUR-8 during mammalian development remains unclear. Here we found that germline deletion of SUR-8 in mice resulted in early embryonic lethality. Inactivated SUR-8 specifically in mouse endothelial cells (ECs) revealed that SUR-8 is essential for embryonic heart development. SUR-8 deficiency in ECs resulted in late embryonic lethality, and the mutant mice displayed multiple cardiac defects. The reduced endothelial-mesenchymal transformation (EMT) and the reduced mesenchyme proliferation phase were observed in the atrioventricular canal (AVC) within the mutant hearts, leading to the formation of hypoplastic endocardial cushions. However, ERK activation did not appear to be affected in mutant ECs, suggesting that SUR-8 may act in an ERK-independent pathway to regulate AVC development. PMID:20549726

Yi, Jing; Chen, Muyun; Wu, Xiaohui; Yang, Xiao; Xu, Tian; Zhuang, Yuan; Han, Min; Xu, Rener

2010-07-01

417

Molecular analysis of the nondisjoined chromosome in trisomy 21 with and without endocardial cushion defects  

SciTech Connect

Congenital heart disease is found in approximately 40% of patients with Down syndrome (DS), with endocardial cushion defects (ECDs) comprising one-third of the defects. Sixteen highly polymorphic microsatellite markers were typed in two groups (Group 1: DS with ECD, n=43, and Group 2: DS without ECD, n=52) to determine: (1) the parental origin of the extra chromosome, (2) the presence or absence of disomic homozygosity (reduced) or heterozygosity (nonreduced) of the markers along 21q, and (3) the presence or absence of recombination in the nondisjoined chromosome. The association of these three factors with the presence of ECD in DS was then determined. The origin of the nondisjoined chromosome was maternal in 86.3% of the total cases with no significant differences between groups 1 and 2. The most centromeric marker was nonreduced in 77% of the maternally-derived trisomies (indicative of a meiosis II nondisjunction) with no significant differences between groups 1 and 2. The most telomeric markers showed no differences in the number of reduced or nonreduced markers between maternally and paternally derived chromosomes or between groups 1 and 2. Recombination was significantly decreased in group 1 (28%) compared to group 2 (56%) (chi-square 7.45, p < 0.01) with similar values for both paternally and maternally-derived trisomies. Overall, recombination was present in 43.2% of the nondisjoined chromosomes which is similar to the 42.3% recombination reported in nondisjoined chromosomes in trisomy 21.

Zittergruen, M.M.; Murray, J.C.; Lauer, R.M. [Univ. of Iowa, Iowa City, IA (United States)] [and others

1994-09-01

418

A nanometric cushion for enhancing scratch and wear resistance of hard films  

PubMed Central

Summary Scratch resistance and friction are core properties which define the tribological characteristics of materials. Attempts to optimize these quantities at solid surfaces are the subject of intense technological interest. The capability to modulate these surface properties while preserving both the bulk properties of the materials and a well-defined, constant chemical composition of the surface is particularly attractive. We report herein the use of a soft, flexible underlayer to control the scratch resistance of oxide surfaces. Titania films of several nm thickness are coated onto substrates of silicon, kapton, polycarbonate, and polydimethylsiloxane (PDMS). The scratch resistance measured by scanning force microscopy is found to be substrate dependent, diminishing in the order PDMS, kapton/polycarbonate, Si/SiO2. Furthermore, when PDMS is applied as an intermediate layer between a harder substrate and titania, marked improvement in the scratch resistance is achieved. This is shown by quantitative wear tests for silicon or kapton, by coating these substrates with PDMS which is subsequently capped by a titania layer, resulting in enhanced scratch/wear resistance. The physical basis of this effect is explored by means of Finite Element Analysis, and we suggest a model for friction reduction based on the "cushioning effect” of a soft intermediate layer. PMID:25161836

Gotlib-Vainshtein, Katya; Girshevitz, Olga; Barlam, David

2014-01-01

419

ROCK1 expression is regulated by TGFbeta3 and ALK2 during valvuloseptal endocardial cushion formation.  

PubMed

During early heart development at the looped heart stage, endothelial cells in the outflow tract and atrioventricular (AV) regions transform into mesenchyme to generate endocardial cushion tissue. This endocardial epithelial-mesenchymal transition (EMT) is regulated by several regulatory pathways, including the transforming growth factor-beta (TGFbeta), bone morphogenetic protein (BMP), and Rho-ROCK pathways. Here, we investigated the spatiotemporal expression pattern of ROCK1 mRNA during EMT in chick and examined whether TGFbeta or BMP could induce the expression of ROCK1. At the onset of EMT, ROCK1 expression was up-regulated in endothelial/mesenchymal cells. A three-dimensional collagen gel assay was used to examine the mechanisms regulating the expression of ROCK1. In AV endocardium co-cultured with associated myocardium, ROCK1 expression was inhibited by either anti-TGFbeta3 antibody, anti-ALK2 antibody or noggin, but not SB431542 (ALK5 inhibitor). In cultured preactivated AV endocardium, TGFbeta3 protein induced the expression of ROCK1, but BMP did not. AV endothelial cells that were cultured in medium supplemented with TGFbeta3 plus anti-ALK2 antibody failed to express ROCK1. These results suggest that the expression of ROCK1 is up-regulated at the onset of EMT and that signaling mediated by TGFbeta3/ALK2 together with BMP is involved in the expression of ROCK1. PMID:18461597

Sakabe, Masahide; Sakata, Hirokazu; Matsui, Hiroko; Ikeda, Kazuo; Yamagishi, Toshiyuki; Nakajima, Yuji

2008-07-01

420

Wettability-independent bouncing on flat surfaces mediated by thin air films  

NASA Astrophysics Data System (ADS)

The impingement of drops onto solid surfaces plays a crucial role in a variety of processes, including inkjet printing, fog harvesting, anti-icing, dropwise condensation and spray coating. Recent efforts in understanding and controlling drop impact behaviour focused on superhydrophobic surfaces with specific surface structures enabling drop bouncing with reduced contact time. Here, we report a different universal bouncing mechanism that occurs on both wetting and non-wetting flat surfaces for both high and low surface tension liquids. Using high-speed multiple-wavelength interferometry, we show that this bouncing mechanism is based on the continuous presence of an air film for moderate drop impact velocities. This submicrometre `air cushion' slows down the incoming drop and reverses its momentum. Viscous forces in the air film play a key role in this process: they provide transient stability of the air cushion against squeeze-out, mediate momentum transfer, and contribute a substantial part of the energy dissipation during bouncing.

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

2015-01-01

421

40 CFR 86.000-24 - Test vehicles and engines.  

Code of Federal Regulations, 2012 CFR

...test vehicle is selected. If air conditioning is projected to be available...selections to engine codes which have air conditioning available and will require...selected under this section has air conditioning installed and...

2012-07-01

422

40 CFR 86.000-24 - Test vehicles and engines.  

Code of Federal Regulations, 2010 CFR

...test vehicle is selected. If air conditioning is projected to be available...selections to engine codes which have air conditioning available and will require...selected under this section has air conditioning installed and...

2010-07-01

423

40 CFR 86.000-24 - Test vehicles and engines.  

Code of Federal Regulations, 2013 CFR

...test vehicle is selected. If air conditioning is projected to be available...selections to engine codes which have air conditioning available and will require...selected under this section has air conditioning installed and...

2013-07-01

424

40 CFR 86.000-24 - Test vehicles and engines.  

Code of Federal Regulations, 2011 CFR

...test vehicle is selected. If air conditioning is projected to be available...selections to engine codes which have air conditioning available and will require...selected under this section has air conditioning installed and...

2011-07-01

425

Respiratory Health and Air Pollution  

MedlinePLUS

... CDC.gov . Healthy Places Share Compartir Respiratory Health & Air Pollution Transportation-related pollutants are one of the largest ... Motor vehicles contribute to more than 50% of air pollution in urban areas. The design of communities and ...

426

A new mulinane diterpenoid from the cushion shrub Azorella compacta growing in Perú  

PubMed Central

Background: Azorella compacta is a rare yellow-green compact resinous cushion shrub growing from the high Andes of southern Perú to northwestern Argentina, and which is a producer of biologically active and unique diterpenoids. Objective: This study investigated the secondary metabolites present in a Peruvian sample of Azorella compacta and the evaluation of gastroprotective activity of the isolated compounds in a gastric- induced ulcer model in mice. Material and Methods: Six secondary metabolites (diterpenoids 1-6) present in the dichloromethane (DCM) extract of A. compacta growing in Perú were isolated by a combination of Sephadex LH-20 permeation and silica gel chromatography and their chemical structures were elucidated by spectroscopic methods (NMR) and molecular modeling. The gastroprotective activity of the new compound 1 was evaluated on the HCl/EtOH-induced gastric lesion model in mice and compared to the activity showed by the known compounds. Results: A new mulinane diterpene along with five known diterpenoids have been isolated from a Peruvian sample of A. compacta and the gastroprotective results show that compound 1 is less active than the other known mulinane diterpenoids isolated. Conclusions: A. compacta growing in Perú showed the presence of the new mulinane 1, which was poorly active in the HCl/EtOH-induced gastric lesion model in mice. Indeed, the activity was lower than other diterpenoids (2-6) showing an oxygenated function at C-16 or/and C-20, which confirm the role of an oxygenated group (OH or carboxylic acid) for the gastroprotective activity of mulinane compounds. PMID:25298672

Salgado, Francisco; Areche, Carlos; Sepúlveda, Beatriz; Simirgiotis, Mario J.; Cáceres, Fátima; Quispe, Cristina; Quispe, Lina; Cano, Teresa

2014-01-01

427

Clinical Evaluation of the Articulinx Intercarpometacarpal Cushion for the First CMC Joint: A Feasibility Study  

PubMed Central

Background The Intercarpometacarpal Cushion (ICMC; Articulinx, Cupertino, CA, USA) is an implantable spacer designed as a less invasive surgical treatment for osteoarthritis (OA) of the first carpometacarpal joint (CMC-1). Description of Technique Following local anesthesia and exposure of the joint capsule the ICMC, attached to a needle and suture tethers, is guided into the joint space under fluoroscopic visualization through a dorsal approach. The needle is pulled through the thenar eminence to the opposite side of the hand and, once proper device placement is confirmed, cut free and the joint capsule closed. Patients and Methods Eight female patients (median age 56 years; range, 42-83) were treated and followed for 6 to 24 months. Safety of the implant procedure was evaluated intraoperatively. Pain, joint function, and strength were evaluated at 6 weeks, 3, 6, 12 and 24 months with a Visual Analog Scale (VAS) for pain, the QuickDASH inventory, Canadian Occupational Performance Measure (COPM), and pinch and grip strength measurements. Results At 2 years (n = 6), mean VAS pain scores decreased from 6.3 (± 1.5) to 2.2 (± 1.1) (p < 0.001), mean QuickDASH scores improved from 47 (± 15) to 31 (± 11) (p < 0.10), mean COPM performance scores improved from 5.0 (± 1.2) to 5.5 ( ± 1.3) (p = NS). Mean pinch and grip strength measurements also improved compared with baseline. No serious adverse events occurred. Two device removals occurred, associated with a traumatic event and Stage IV OA with device displacement, at 6 and 9 months respectively. Conclusion The ICMC can be implanted safely. Effectiveness needs to be confirmed in future studies. PMID:24436828

van der Veen, Fiente J. C.; White, David N.; Dapper, Mattie M. L.; Griot, J. Peter W. don; Ritt, Marco P. J. F.

2013-01-01

428

65 FR 16899 - Availability of Government-Owned Inventions for Licensing  

Federal Register 2010, 2011, 2012, 2013, 2014

...AIR-DELIVERED POSITION MARKING DEVICE AND METHOD; filed 8 December 1997; patented 14 September 1999.//Patent 5,951,607: AUTONOMOUS CRAFT CONTROLLER SYSTEM FOR LANDING CRAFT AIR CUSHIONED VEHICLE; filed 6 March 1997; patented 14 September...

2000-03-30

429

Metal-air battery assessment  

SciTech Connect

The objective of this report is to evaluate the present technical status of the zinc-air, aluminum/air and iron/air batteries and assess their potential for use in an electric vehicle. In addition, this report will outline proposed research and development priorities for the successful development of metal-air batteries for electric vehicle application. 39 refs., 25 figs., 11 tabs.

Sen, R.K.; Van Voorhees, S.L.; Ferrel, T.

1988-05-01

430

Design of an environmental assessment model on the effect of vehicle emission in greater Tehran on air pollution with economic sensitivity  

Microsoft Academic Search

Air pollution is the presence of pollutants in the atmosphere from anthropogenic or natural substances in quantities likely to harm human, plant or animal life; to damage human-made materials and structures; to bring about changes in weather or climate; or to interfere with enjoyment of life or property. With regard to the quality of air in most of the megacities

M. Abbaspour; A. Soltaninejad

431

Experimental Aeroheating Study of Mid-L/D Entry Vehicle Geometries: NASA LaRC 20-Inch Mach 6 Air Tunnel Test 6966  

NASA Technical Reports Server (NTRS)

Aeroheating data on mid lift-to-drag ratio entry vehicle configurations has been obtained through hypersonic wind tunnel testing. Vehicles of this class have been proposed for high-mass Mars missions, such as sample return and crewed exploration, for which the conventional sphere-cone entry vehicle geometries of previous Mars missions are insufficient. Several configurations were investigated, including elliptically-blunted cylinders with both circular and elliptical cross sections, biconic geometries based on launch vehicle dual-use shrouds, and parametrically-optimized analytic geometries. Testing was conducted at Mach 6 over a range of Reynolds numbers sufficient to generate laminar, transitional, and turbulent flow. Global aeroheating data were obtained using phosphor thermography. Both stream-wise and cross-flow transition occured on different configurations. Comparisons were made with laminar and turbulent computational predictions generated with an algebraic turbulence model. Predictions were generally in good agreement in regions of laminar or fully-turbulent flow; however for transitional cases, the lack of a transition onset prediction capability produced less accurate comparisons. The data obtained in this study are intended to be used for prelimary mission design studies and the development and validation of computational methods.

Hollis, Brian R.; Hollingsworth, Kevin E.

2014-01-01

432

A Review of Intelligent Systems Software for Autonomous Vehicles  

Microsoft Academic Search

The need for intelligent unmanned vehicles has been steadily increasing. These vehicles could be air-, ground-, space-, or sea-based. This paper will review some of the most common software systems and methods that could be used for controlling such vehicles. Early attempts at mobile robots were confined to simple laboratory environments. For vehicles to operate in real-world noisy and uncertain

L. N. Long; S. D. Hanford; O. Janrathitikarn; G. L. Sinsley; J. A. Miller

2007-01-01

433

Air bag restraint device  

DOEpatents

A rear-seat air bag restraint device is disclosed that prevents an individual, or individuals, from continuing violent actions while being transported in a patrol vehicle`s rear seat without requiring immediate physical contact by the law enforcement officer. The air bag is activated by a control switch in the front seat and inflates to independently restrict the amount of physical activity occurring in the rear seat of the vehicle while allowing the officer to safely stop the vehicle. The air bag can also provide the officer additional time to get backup personnel to aid him if the situation warrants it. The bag is inflated and maintains a constant pressure by an air pump. 8 figs.

Marts, D.J.; Richardson, J.G.

1995-10-17

434

Thermal management optimization of an air-cooled Li-ion battery module using pin-fin heat sinks for hybrid electric vehicles  

NASA Astrophysics Data System (ADS)

Three dimensional transient thermal analysis of an air-cooled module that contains prismatic Li-ion cells next to a special kind of aluminum pin fin heat sink whose heights of pin fins increase linearly through the width of the channel in air flow direction was studied for thermal management of Lithium-ion battery pack. The effects of pin fins arrangements, discharge rates, inlet air flow velocities, and inlet air temperatures on the battery were investigated. The results showed that despite of heat sinks with uniform pin fin heights that increase the standard deviation of the temperature field, using this kind of pin fin heat sink compare to the heat sink without pin fins not only decreases the bulk temperature inside the battery, but also decreases the standard deviation of the temperature field inside the battery as well. Increasing the inlet air temperature leads to decreasing the standard deviation of the temperature field while increases the maximum temperature of the battery. Furthermore, increasing the inlet air velocity first increases the standard deviation of the temperature field till reaches to the maximum point, and after that decreases. Also, increasing the inlet air velocity leads to decrease in the maximum temperature of the battery.

Mohammadian, Shahabeddin K.; Zhang, Yuwen

2015-01-01

435

Electric vehicles  

NASA Astrophysics Data System (ADS)

Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. These concepts are discussed.

1990-03-01

436

Electric vehicles  

SciTech Connect

Quiet, clean, and efficient, electric vehicles (EVs) may someday become a practical mode of transportation for the general public. Electric vehicles can provide many advantages for the nation's environment and energy supply because they run on electricity, which can be produced from many sources of energy such as coal, natural gas, uranium, and hydropower. These vehicles offer fuel versatility to the transportation sector, which depends almost solely on oil for its energy needs. Electric vehicles are any mode of transportation operated by a motor that receives electricity from a battery or fuel cell. EVs come in all shapes and sizes and may be used for different tasks. Some EVs are small and simple, such as golf carts and electric wheel chairs. Others are larger and more complex, such as automobile and vans. Some EVs, such as fork lifts, are used in industries. In this fact sheet, we will discuss mostly automobiles and vans. There are also variations on electric vehicles, such as hybrid vehicles and solar-powered vehicles. Hybrid vehicles use electricity as their primary source of energy, however, they also use a backup source of energy, such as gasoline, methanol or ethanol. Solar-powered vehicles are electric vehicles that use photovoltaic cells (cells that convert solar energy to electricity) rather than utility-supplied electricity to recharge the batteries. This paper discusses these concepts.

Not Available

1990-03-01

437

19 CFR 12.73 - Motor vehicle and engine compliance with Federal antipollution emission requirements.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 false Motor vehicle and engine compliance with Federal antipollution...73 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...of Motor Vehicles, Motor Vehicle Engines and Nonroad Engines Under the Clean Air...

2013-04-01

438

19 CFR 12.73 - Motor vehicle and engine compliance with Federal antipollution emission requirements.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 false Motor vehicle and engine compliance with Federal antipollution...73 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...of Motor Vehicles, Motor Vehicle Engines and Nonroad Engines Under the Clean Air...

2011-04-01

439

19 CFR 12.73 - Motor vehicle and engine compliance with Federal antipollution emission requirements.  

Code of Federal Regulations, 2010 CFR

... 2010-04-01 false Motor vehicle and engine compliance with Federal antipollution...73 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...of Motor Vehicles, Motor Vehicle Engines and Nonroad Engines Under the Clean Air...

2010-04-01

440

19 CFR 12.73 - Motor vehicle and engine compliance with Federal antipollution emission requirements.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 false Motor vehicle and engine compliance with Federal antipollution...73 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND...of Motor Vehicles, Motor Vehicle Engines and Nonroad Engines Under the Clean Air...

2012-04-01

441

40 CFR 86.1830-01 - Acceptance of vehicles for emission testing.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1830-01...

2012-07-01

442

40 CFR 86.1817-05 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-05...

2013-07-01

443

40 CFR 86.1830-01 - Acceptance of vehicles for emission testing.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1830-01...

2013-07-01

444

40 CFR 86.1817-08 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-08...

2011-07-01

445

40 CFR 86.1863-07 - Optional chassis certification for diesel vehicles.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1863-07...

2010-07-01

446

40 CFR 86.1830-01 - Acceptance of vehicles for emission testing.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1830-01...

2011-07-01

447

40 CFR 86.1816-08 - Emission standards for complete heavy-duty vehicles.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1816-08...

2011-07-01

448

40 CFR 86.1830-01 - Acceptance of vehicles for emission testing.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1830-01...

2010-07-01

449

40 CFR 86.1816-08 - Emission standards for complete heavy-duty vehicles.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1816-08...

2010-07-01

450

40 CFR 86.1831-01 - Mileage accumulation requirements for test vehicles.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1831-01...

2010-07-01

451

40 CFR 86.1831-01 - Mileage accumulation requirements for test vehicles.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1831-01...

2011-07-01

452

40 CFR 86.1831-01 - Mileage accumulation requirements for test vehicles.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1831-01...

2013-07-01

453

40 CFR 86.1831-01 - Mileage accumulation requirements for test vehicles.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1831-01...

2012-07-01

454

40 CFR 86.1817-08 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-08...

2013-07-01

455

40 CFR Appendix I to Subpart S of... - Vehicle Procurement Methodology  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles Pt. 86, Subpt. S,...

2012-07-01

456

40 CFR 86.1817-08 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-08...

2012-07-01

457

40 CFR 86.1863-07 - Chassis certification for diesel vehicles.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1863-07...

2012-07-01

458

40 CFR 86.1863-07 - Chassis certification for diesel vehicles.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1863-07...

2013-07-01

459

40 CFR 86.1817-05 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-05...

2012-07-01

460

40 CFR 86.1836-01 - Manufacturer-supplied production vehicles for testing.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1836-01...

2012-07-01

461

40 CFR 86.1817-05 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-05...

2011-07-01

462

40 CFR 86.1836-01 - Manufacturer-supplied production vehicles for testing.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1836-01...

2010-07-01

463

40 CFR 86.1817-05 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-05...

2010-07-01

464

40 CFR Appendix I to Subpart S of... - Vehicle Procurement Methodology  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles Pt. 86, Subpt. S,...

2011-07-01

465

40 CFR 86.1816-08 - Emission standards for complete heavy-duty vehicles.  

Code of Federal Regulations, 2012 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1816-08...

2012-07-01

466

40 CFR Appendix I to Subpart S of... - Vehicle Procurement Methodology  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles Pt. 86, Subpt. S,...

2010-07-01

467

40 CFR 86.1816-08 - Emission standards for complete heavy-duty vehicles.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1816-08...

2013-07-01

468

40 CFR 86.1836-01 - Manufacturer-supplied production vehicles for testing.  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1836-01...

2013-07-01

469

40 CFR 86.1817-08 - Complete heavy-duty vehicle averaging, trading, and banking program.  

Code of Federal Regulations, 2010 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1817-08...

2010-07-01

470

40 CFR Appendix I to Subpart S of... - Vehicle Procurement Methodology  

Code of Federal Regulations, 2013 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles Pt. 86, Subpt. S,...

2013-07-01

471

40 CFR 86.1836-01 - Manufacturer-supplied production vehicles for testing.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1836-01...

2011-07-01

472

40 CFR 86.1863-07 - Optional chassis certification for diesel vehicles.  

Code of Federal Regulations, 2011 CFR

...HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1863-07...

2011-07-01

473

5-Star Safety Ratings: 1990-2010 Vehicles  

MedlinePLUS

5-Star Safety Ratings 2011-Newer Vehicles 1990-2010 Vehicles Air Bags Child Safety at Parents Central Resources Rollover ... to the most frequently asked questions about 5-Star Safety Ratings. Shop Smart for a Safer Car, ...

474

Mapping sub-antarctic cushion plants using random forests to combine very high resolution satellite imagery and terrain modelling.  

PubMed

Monitoring changes in the distribution and density of plant species often requires accurate and high-resolution baseline maps of those species. Detecting such change at the landscape scale is often problematic, particularly in remote areas. We examine a new technique to improve accuracy and objectivity in mapping vegetation, combining species distribution modelling and satellite image classification on a remote sub-Antarctic island. In this study, we combine spectral data from very high resolution WorldView-2 satellite imagery and terrain variables from a high resolution digital elevation model to improve mapping accuracy, in both pixel- and object-based classifications. Random forest classification was used to explore the effectiveness of these approaches on mapping the distribution of the critically endangered cushion plant Azorella macquariensis Orchard (Apiaceae) on sub-Antarctic Macquarie Island. Both pixel- and object-based classifications of the distribution of Azorella achieved very high overall validation accuracies (91.6-96.3%, ? = 0.849-0.924). Both two-class and three-class classifications were able to accurately and consistently identify the areas where Azorella was absent, indicating that these maps provide a suitable baseline for monitoring expected change in the distribution of the cushion plants. Detecting such change is critical given the threats this species is currently facing under altering environmental conditions. The method presented here has applications to monitoring a range of species, particularly in remote and isolated environments. PMID:23940805

Bricher, Phillippa K; Lucieer, Arko; Shaw, Justine; Terauds, Aleks; Bergstrom, Dana M

2013-01-01

475

Identification and characterization of a novel Schwann and outflow tract endocardial cushion lineage-restricted periostin enhancer  

PubMed Central

Periostin is a fasciclin-containing adhesive glycoprotein that facilitates the migration and differentiation of cells that have undergone epithelial-mesenchymal transformation during embryogenesis and in pathological conditions. Despite the importance of post-transformational differentiation as a general developmental mechanism, little is known how periostin’s embryonic expression is regulated. To help resolve this deficiency, a 3.9kb periostin proximal promoter was isolated and shown to drive tissue-specific expression in the neural crest-derived Schwann cell lineage and in a sub-population of periostin-expressing cells in the cardiac outflow tract endocardial cushions. In order to identify the enhancer and associated DNA binding factor(s) responsible, in vitro promoter dissection was undertaken in a Schwannoma line. Ultimately a 304bpperi enhancer was identified and shown to be capable of recapitulating 3.9kbperi-lacZ in vivo spatiotemporal patterns. Further mutational and EMSA analysis helped identify a minimal 37bp region that is bound by the YY1 transcription factor. The 37bp enhancer was subsequently shown to be essential for in vivo 3.9kbperi-lacZ promoter activity. Taken together, these studies identify an evolutionary-conserved YY1-binding 37bp region within a 304bp periostin core enhancer that is capable of regulating simultaneous novel tissue-specific periostin expression in the cardiac outflow-tract cushion mesenchyme and Schwann cell lineages. PMID:17540359

Lindsley, Andrew; Snider, Paige; Zhou, Hongming; Rogers, Rhonda; Wang, Jian; Olaopa, Michael; Kruzynska-Frejtag, Agnieszka; Koushik, Shrinagesh V.; Lilly, Brenda; Burch, John B.E.; Firulli, Anthony B.; Conway., Simon J.

2007-01-01

476

Polymer-cushioned bilayers. II. An investigation of interaction forces and fusion using the surface forces apparatus.  

PubMed Central

We have created phospholipid bilayers supported on soft polymer "cushions" which act as deformable substrates (see accompanying paper, Wong, J. Y., J. Majewski, M. Seitz, C. K. Park, J. N. Israelachvili, and G. S. Smith. 1999. Biophys. J. 77:1445-1457). In contrast to "solid-supported" membranes, such "soft-supported" membranes can exhibit more natural (higher) fluidity. Our bilayer system was constructed by adsorption of small unilamellar dimyristoylphosphatidylcholine (DMPC) vesicles onto polyethylenimine (PEI)-supported Langmuir-Blodgett lipid monolayers on mica. We used the surface forces apparatus (SFA) to investigate the long-range forces, adhesion, and fusion of two DMPC bilayers both above and below their main transition temperature (T(m) approximately 24 degrees C). Above T(m), hemi-fusion activation pressures of apposing bilayers were considerably smaller than for solid-supported bilayers, e.g., directly supported on mica. After separation, the bilayers naturally re-formed after short healing times. Also, for the first time, complete fusion of two fluid (liquid crystalline) phospholipid bilayers was observed in the SFA. Below T(m) (gel state), very high pressures were needed for hemi-fusion and the healing process became very slow. The presence of the polymer cushion significantly alters the interaction potential, e.g., long-range forces as well as fusion pressures, when compared to solid-supported systems. These fluid model membranes should allow the future study of integral membrane proteins under more physiological conditions. PMID:10465756

Wong, J Y; Park, C K; Seitz, M; Israelachvili, J

1999-01-01

477